IRLF
ETROL AlR-GAS
Henry O'Connor
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AEROGEN SAFETY GAS.
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HIGHEST TESTIMONIALS.
Six Gold Medals.
WITH THE WEIGHT-DRIVEN MACHINE THE LIGHT IS ALWAYS AVAILABLE
Machines also supplied driven by Hot-air Motors, Water Motors, Ac., and Storage Holders.
ADVANTAGES OF ,
AEROGEN GAS.
High illuminating power. Small consumption. Small pipes can be used.
Burners and mantles have* a long life.
Non-explosive.
Uniform mixture always pro- duced.
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" Country-House Lighting."
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PETROL QA5.
THE DELAITTE SYSTEM.
OVER 8000 SATISFACTORY INSTALLATIONS.
Is particularly suitable for country houses, small towns, factories, schools, and churches, as whilst its illuminating power is 2O per cent, greater than that of coal-gas, its use shows great economy over all other methods of lighting adopted by British Railway Companies.
SALIENT FEATURES «| ESTIMATES FREE.
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EDIIMESUFSGH A IM O GLASGOW.
PETROL AIR-GAS
A PRACTICAL HANDBOOK
OAr THE INSTALLATION AND WORKING OF
AIR -GAS LIGHTING SYSTEMS FOR
COUNTRY HOUSES
BY
HENRY O'CONNOR
FELLOW OF THE ROYAL SOCIETY, EDINBURGH
ASSOCIATE MEMBER OF THE INSTITUTION OF CIVIL ENGINEERS 1'AST PRESIDENT OF THE SOCIETY OF ENGINEERS
LONDON CROSBY LOCKWOOD AND SON
7 STATIONERS' HALL COURT, LUDGATE HILL 1909
Printed at THE DARIEN PRESS, Edinburgh,
PREFACE.
THE danger of fire where paraffin lamps are used has long been recognised, hence the numerous plants which have been invented to obviate their use.
The latest process is the Petrol Air-Gas System, and the following pages have been written to help those who are proposing the installation of such a plant, in the choosing and working of same.
As this book is intended for the lay reader, as little reference as possible has been made to technical
matters.
HENRY O'CONNOR.
i DRUMMOND PLACE, EDINBURGH.
CONTENTS.
CHAPTER I.
Description of Previous Plants and Systems for Country- House Lighting — Difficulties with — Objections and Prices - - I
CHAPTER II. History of Petrol Gas — Comparative Costs 10
CHAPTER IJI.
Petrol — Its Nature, Dangers, and Storing — Notes on the
Law regarding same - 13
CHAPTER IV. Burners — Description of same — Piping — Mantles 24
CHAPTER V.
General Principles of Parts of Plants — Motive Power Meters — Weight-driven Plants — Root's Blowers — Hot-air Engines— Pelton Water- Wheels - 31
CHAPTER VI. Descriptions of Various Plants - 38
CHAPTER VII.
Extract from an Act for the safe keeping of Petroleum
and other Substances of a like nature • 63
APPENDIX.
Useful Notes . . 69
INDEX ....... 7I
PETROL AIR-GAS.
CHAPTER I.
Description of Previous Plants and Systems for Country- House Lighting — Difficulties with — Objections and Prices.
THE question of the provision of light in houses, which are situated at too great a distance from the usual town supply of gas or electricity to warrant the laying of pipes or leads for the conveyance of such forms of light, has interested the inventor and the public for many years past. The use of lamps, burning either colza or paraffin oil, has always had its objections, not the least of these being the imperative need of daily attention, trimming of wicks, and the refilling of each separate unit, with all its attendant mess and trouble, and also the liability of breakage of the necessary chimneys and possible pilfering of oil by servants. The first of these types of lamps had no danger attached to its use, but it required somewhat expensive and elaborate lamps with clockwork contained in them to ensure the full supply of the oil to the wicks. The latter type are always accompanied by an objectionable odour, as even the very best lamps are liable to creeping of the paraffin which then covers the out- side of the container with a film of oil. These objections are small, however, when compared with the danger always present when such lamps are in use, the overturning of an unattached lamp, especially if it should have a glass or china reservoir, generally resulting in a conflagration more or less
A
PETROL AIR-GAS.
serious. In fact the fire statistics show that the greater number of fires in our cities are due to the use of paraffin lamps, and therefore any means of procuring light which removes this ever-present danger must receive attention from a large number of persons.
The lamp up to quite recently has been the only practical means to the hand of the proprietor of a house of moderate size and whose purse is also only of moderate dimensions. For the owner of a large country mansion there have been several types of gas-making plant obtainable. In a great number of such mansions a coal-gas plant has been installed, generally worked by one of the gardeners or a handy-man on the estate. These plants followed closely those employed for the lighting of small villages, but generally the gas was not purified to the same extent, and the quantity of gas obtainable from a ton of coal was not nearly so great.
The plant consists, in most cases, of a single retort made of cast iron instead of fireclay, on account of its being frequently heated and allowed to cool, which would make the fireclay crack, and so allow the gas to escape, instead of passing to what is properly called the gasholder, but more generally the gasometer. This retort is supplied with a furnace and set in firebricks, so that the heat can pass slowly around it, and thence to a flue and to the chimney; the gas from the coal, which is placed inside the retort as soon as it is hot, passes up a pipe and then down into a sealing chamber called a hydraulic main, which prevents the return of the gas when the door is opened for the removal of the coke and refilling with fresh coal. Here is deposited some of the tar and ammoniacal liquor contained in the coal, while still more is thrown down as the gas passes through the condenser, a vessel composed of a number of pipes which are exposed to the atmosphere, so that the gas is cooled to the temperature of the air.
COAL-GAS PLANTS.
In a large gas-works a washer and scrubber are provided to remove all the final traces of tar and ammonia, but these pieces of apparatus are not usually to be found in the private gas-works, so that the gas passes direct to the purifier or purifiers, which are boxes containing wetted lime on grids, through which the gas passes and delivers up the impurities, carbonic acid, sulphuretted hydrogen, and perhaps some of the other sulphur compounds. The purification, so far as it is carried, is now complete, and the gas is then led direct to the gasholder to be stored until it is required for use.
As it is not usually found convenient to keep a man constantly employed making gas, and indeed it would prove very expensive if such constant attendance were required, the gasholder must be large enough so as to contain probably a sufficiency for a week's supply, and this is perhaps the portion of the plant costing the largest proportion of the whole apparatus, which may be taken as costing on an average about ^400 (without counting the price of the build- ings) in even the most favourable circumstances, while the gas made will vary in cost according to the quality of the coal used, the cost of its carriage and carting, the labour expended and available, but in any case cannot be less than 53. to 6s. per 1,000 cubic feet, and may easily reach double that figure, with a candle-power of say 16 to 20. Despite this cost, however, a very large number of such gas-works are to be found in country houses in outlying districts.
Another form of gas plant which has been received with some favour in the past has been one in which a crude form of petroleum has been gasified. Here also some of the plant already described for the coal-gas manufacture has to be provided, a cast-iron retort of a different form, set in a fire- brick furnace encased in iron, a washer or hydraulic main, a condenser and gasholder ; but this latter need not be quite
PETROL AIR-GAS.
so large, as the gas made from the oil will be much richer and capable of giving a light of some 45 to 50 candle-power, and therefore less will be required for the same light than if coal-gas were being used. The house for the plant is not required to be large, and the gasholder is fixed in the open, as it is not affected by exposure to the weather. This gas- holder is a bottomless iron bell moving up and down in a tank of water, which tank is usually made of brickwork in a hole excavated in the ground, and backed up with puddle to ensure its being watertight.
The crude shale oil is run in from an overhead tank into the retort in a fine stream through a syphon to prevent the escape of gas. When the oil reaches the red-hot retort it is instantly cracked and converted into a fixed gas, which should not condense or be converted into oil again. The retort has to be periodically cleaned out after each period of gas- making, and a certain amount of fuel, coal, wood, or gas is required to keep the retort red hot. Such a plant, although cheaper than the coal-gas plant already described, will cost, say, ^285 for fifty lights, while the cost of such gas will not often be much below 123. per 1,000 cubic feet.
The more modern plan of lighting country houses by means of acetylene gas has some points of advantage. Acetylene is a combination of carbon and hydrogen (C2H2), and by weight 92.3 per cent. C and 7.7 per cent. H. It has a specific gravity of .9, or about twice the weight of coal-gas. It is easiest made from calcium carbide (CaC2), which con- tains 62.5 per cent, by weight of calcium and 37.5 per cent, of carbon, and these are fused together in an electric furnace. It decomposes in contact with water according to the equation CaC2 + 2H2O = Ca(H2O2) (slaked lime), plus C2H2 (acetylene), making from 4 to 5 cubic feet per Ib. of the carbide. It then gives up the stored or latent heat which it gained in the electric furnace, so that it gives off 753
ACETYLENE FLAWS.
B.Th.U. per lb., and this is where the difficulty of designing a good generator comes in. The impurities present are ammonia, sulphuretted hydrogen, and phosphuretted hydro- gen, and perhaps some other compounds of sulphur and phosphorus, if the heat of generation has been too great. The materials generally used for purifying are chloride of lime, an acid solution of cuprous chloride, or a solution of chromic acid, the two latter absorbed in kieselguhr. The gas should also be allowed to bubble through water to take out the soluble impurities, and also to cool the gas.
The best apparatus, it has always been the writer's opinion, and this is confirmed by the Government Acetylene Committee, is one much on the lines of a coal-gas works, wherein the carbide is placed into a water-cooled retort, and the gas carried to a gasholder large enough for one day's consumption, and thence as required through the purifying apparatus, the automatic apparatus being liable to get out of order in the hands of the inexperienced. The pressure is kept from 2 J inches to 3 inches water column, and the larger sizes of burners give the greater proportion of light. The burner has to be of peculiar construction to ensure con- tinuously good lighting, as the gas being so rich in carbon, it is easily deposited on the tip and causes smoking. The proper burner allows air to approach the outlet of the gas by side channels, and the jets issue some distance apart from the spot where they unite and form the flat flame.
The candle-power of acetylene gas is 240 candles when calculated to a rate of 5 cubic feet per hour. The gas costs some 505. per 1,000 cubic feet, so that any loss through leakage in pipe or fittings is a very expensive matter, and the quantity lost, despite the greater specific gravity of the gas, is about the same as with ordinary coal-gas, owing to it being supplied at a higher pressure. The small quantity used is an
PETROL AIR-GAS.
advantage, in that it does not vitiate as much air as the coal-gas flame, and the heat given off is less.
Explosions, which have certainly been more heard of from the Continent than in this country, are generally found to have taken place when the gas has been under a pressure of over 2 atmospheres or 30 Ibs. per square inch. Copper, however, has caused trouble, and should never be used, as in the presence of moisture copper acetylide is formed, which is a red precipitate, and will explode when heated or struck, but if the copper be in an acid solution, the acetylide cannot be formed. The fittings for acetylene gas require to be specially made, as they have to be better fitting, and have their surfaces ground in, owing to the searching nature of the gas. Burners may now be obtained which give three times the light of the gas in the flat flame, but the lasting power of the necessary mantles is not very great.
Electric light for country houses is only possible on a somewhat extended scale, as power of some kind has to be available for manufacturing the electricity, and this is of itself a costly item, besides the necessity of having a man to look after the installation who understands something of the process, and this man is not usually to be found in the service of the owner of the house. For such lighting, a dynamo, to make the current, has to be driven at a high speed by means of an engine, which may be either worked by oil or petrol or steam, and both these have to be looked after, oiled, and kept clean, and where arrangements cannot be made for watching the plant during the working, or rather lighting hours, accumulators have to be installed, which are costly, and require considerable room. They, however, act as a stand-by during any temporary breakdown of the plant, and serve for giving out current during the night, if few lamps only are required. Beside the first cost they are liable to require frequent renewals or repairs which add to the
ELECTRIC PLANTS.
expense of the light. It would not be wise, however, to do without them where reliability is required.
The arrangement usually adopted then consists of an engine to drive the dynamo, which manufactures the current, and this dynamo must run at a high and very regular speed if the light is to be steady and even, and any fluctuation is extremely objectionable. An ampere-meter and a volt-meter are required and to be understood, and also various forms of "cut-out" to regulate the quantity and strength of the current, according to the speed of the dynamo and the number of lamps in use.
We have thus four systems which have been adopted in recent times for lighting where gas and electricity supply works are not available. There have also been other plans of obtaining light without oil lamps, such as the "Alpha" and " Sun " gas-making machines, which will be described later. Enough has been said, however, to show the many details which have to be understood and attended to with each of the four plants, and we may now perhaps enumerate these.
With a coal-gas plant we have the trouble of carting a supply of coal of a special quality to the site, also a certain quantity of lime, and the distribution of the latter when fouled, which, while usually readily taken by farmers, has a most objectionable smell, and has frequently to be stored until a sufficient amount has accumulated to make it worth while to cart it away. The ammoniacal liquor has to be got rid of, but this can be watered down and used, in place of nitrate of soda, for agricultural purposes ; the tar can generally be utilised locally. And last, the attendance of a man during the hours of gasmaking and some hours before, while the apparatus is being heated up, all make for expense in working.
With the oil-gas plant there is less carting to be done, as
PETROL AIR-GAS.
the oil makes more gas per ton than the coal, and there are less residuals to be disposed of, but the trouble of making is nearly as great as in the case of the coal gas. The gas made is rich but expensive, and special fittings are generally required.
As regards acetylene lighting, this at first seemed the solution of the difficulty, but the calcium carbide has to be obtained and carefully stored ; although this can be obtained in most towns in small quantities at a very high price, com- pared with that charged for the same in bulk, there is always the trouble of getting rid of the sludge made and a possible danger in its use, not to mention a most disagreeable odour should the gas escape. The purifying, also, has to be watched, as if this is not attended to there is an objection- able smell when the light is burning, and a haze spread over the room.
With electricity the expense is the principal objection, although the trouble of supervision is greater than with acetylene, and the cost of the use of electricity for heating and cooking is prohibitive.
Up to quite recently no other system had been found to take the place of these, but now the petrol safety plants which have been introduced seem to have few, if any, of the troubles which beset the other illuminants. They can be filled with petrol and worked by a domestic, male or female, and require little or no attention while working. The safety is assured by the fact that the gas made is practically in- explosible, owing to the small quantity of vapour employed. The price, both for the original outlay and the working, is very low as compared with the others, and the petrol can be obtained everywhere, as it is the same as that used for motor cars, which have caused a great number of depots to be opened in all parts of the country ; while the fact that the gas can be used for heating or cooking makes it almost
PETROL PLANTS.
as useful as coal-gas itself. The fact that a full supply of air to ensure complete combustion is passed through the pipes to the burner, satisfactorily prevents the deprivation of the atmosphere of the room from oxygen, and the pro- ducts of combustion are only the harmless carbon dioxide, there being no sulphur, ammonia, sulphuretted or phosphur- etted hydrogen carried with the gas.
CHAPTER II.
History of Petrol Gas — Comparative Costs.
THE use of the lighter hydrocarbons for gas-making pur- poses is not a new thing, as in 1831 Lowe took out a patent (No. 6,179), anc* again in 1841 (No. 8,883). Van Vriesland invented what he called "Aerogene Gas"; he used a revolving coil of pipes dipping into the spirit, while air passed through the pipes and was thus carburetted and formed a rich gas of some 30 candles-power per cubic foot when used in an ordinary C Welsbach burner at a pressure of from 6 to 8 inches. The difficulty he experienced was with the varying temperatures, which caused a greater or lesser quantity of the vapour to be taken up by the passing air, and conse- quently an adjustment of the air allowed to enter the burner is required.
Curtains of flannel dipping in the petrol have been often used in the carburettors, and these keep moist by the attraction, in the same way that a wick draws up the oil in a lamp — in fact, such carburettors are frequently called " wick " carburettors. The name " carburettor " is given to that portion of the apparatus in which the petrol, or other hydrocarbon liquid, is vaporised, and the air saturated, more or less, with carbon vapour. If a rich gas, which will require some 3 to 6 gallons of gasoline per 1,000 cubic feet of air, is required, it has to be used immediately as it is made, or some of the spirit is likely to be condensed in the pipes, should they be colder than the carburettor. This gas will burn in an ordinary flat-flame or Argand burner.
HEATING FLAMES. II
Hooker was probably the first to make a non-explosive spirit gas, and this was, of course, only useful with mantles, as it had no illuminating power of itself. This fact must be distinctly understood, that ihe Safety Petrol gas can only be used as a heating and not a lighting gas, as there is practi- cally no light in the flame, only of a blue kind, which is intensely hot, and therefore admirable for use in the burner made for heating an incandescent mantle, where the hotter the flame the greater the light. If a gas is required to give a lighting flame, then more vapour must be taken up by the air, and then it is no longer non-explosive, as there will be enough of the hydrocarbon to form an explosive mixture when combined with a certain quantity of the atmosphere. The gas made in the safety plants, however, contains an insufficient quantity of such vapours to form an explosive mixture even without the addition of more air, so that should there be an escape, then the vapour is still more watered down and made poorer, thus an explosive mixture is almost impossible. The real novelty in the Petrol Safety gases is that contained in the finding out that a gas could be made to burn at a suitable burner which was so poor in hydrocarbon vapour that it was hardly capable of exploding.
The difficulty with all gases made by the passing of air over a liquid hydrocarbon is to ensure that this liquid is always of the same vapour tension, or in other words, has the same power of evaporating. If the air is passed over a mass of petrol, then the more volatile parts will evaporate first, and the air will be over-enriched, and the gas too strong, and later, when the less volatile portion of the petrol is reached, the gas will be of too poor a quality.
The petrol supplied nowadays is fairly uniform in gravity and vapour tension, so that some of the difficulties in the past have disappeared.
The question of safety is the most important in any
PETROL AIR-GAS.
system of lighting which is to be operated by unskilled labour, such as domestics, male and female, and this must be assured in any installation of the petrol gas. The gas itself, as has been explained, is to all intents and purposes non-explosive. In fact, a light could be thrown into the gasholder, when the gas might light, but there would be no explosion. In the same way, when lighting a burner or a gas-stove, there is no explosion to shatter the mantles or nerves, as is the case with coal-gas, if turned on before the light is offered to it. Escapes, however, can be detected, because the gas has a distinct odour, which is not objection- able, and must not be confounded with the smell from motor cars, which is not due to petrol, as many suppose, but to the burnt oil used for lubrication of the cylinder, which is subjected to a very high heat. The gas, however, when burning, has no smell, and the safety is still further assured as the gas will only burn at a suitably arranged burner, so that should a light be applied to a leak, it will not light the issuing gas, but most probably the light itself will be extinguished.
A plant complete, for about 10 to 15 lights, will cost from ;£2o upwards, and a comparative test of petrol gas used in a burner giving a light of 40 candle-power, and consuming 6.3 cubic feet of the air-gas with petrol at is. 4d. per gallon, gives 427 candle hours per id. Coal-gas, at 33. per 1,000 cubic feet, gives 555 candle hours per id., so that the cost of the petrol air-gas may be said to equal coal- gas at 33. i id. per 1,000 cubic feet, or in round figures, 45. per 1,000.
It might be mentioned here that makers generally speak of the efficiency of their plants by the number of candle hours obtainable from a gallon of petrol, or in other words how many hours' burning of a certain candle-power will one gallon of petrol provide ?
CHAPTER III.
Petrol — Its Nature, Dangers, and Storing — Notes on the Law regarding same.
PETROLEUM, from the Latin petra (a rock) and oleum (oil), is found in many parts of the world, but the petrol which has been brought to this country has been controlled by two powerful concerns. Some has come from Rou mania and the Dutch East Indies, brought by the Shell Transport and Trading Company, the Asiatic, the Royal Dutch, and the British Petroleum Companies, and some by the Anglo- American Oil Company from the American oil-fields.
More recently, a new source of supply has been added to the above by the opening of a branch in London of the Societe Anonyme des Petroles de Grosnyi, which will bring some 20,000 tons, or 6,000,000 gallons, annually to this country. The importance of this latter supply to users is that so long as the owners keep out of the combine, formerly controlling the market, the competition will tend to the reduction of prices. The amount of Russian oil thus available will equal about one-fifth of the whole quantity imported, as, according to the Board of Trade returns for 1907, about 100,000 tons, or 30,000,000 gallons, were delivered into this country.
From the crude petroleum is obtained "petrol," "motor spirit " or " carburine," and " gasoline," by means of fractional distillation, and they are the product by re-distillation from the 8 to 10 per cent, of naphtha contained in the petroleum, and consist of about 84 per cent, carbon and 16 per cent.
14 PETROL AIR-GAS.
hydrogen. It is called "gasoline," from its use in air-gas machines, and this is of a specific gravity of 0.680 (water = 1,000), or 76° Baume, with a boiling-point between 120° and 250° F., and a vapour pressure at 155° F. of 10 Ibs. per square inch, rising to 40 Ibs. per square inch at 212° F. Hofer gives the boiling-point of gasoline spirit, of specific gravity 0.640 to 0.667, at 15&° to 176° F. (70° to 80° C.), and of spirit of 0.667 to 0.707 specific gravity as 176° to 212° F. (80° to 1 00° C.). Gasoline is principally composed of pentane (C5H12), 0.628 specific gravity, boiling-point 76° to 128° F. (24.5° to 53° C.); hexane (C6H14), boiling- point 156° F. (69° C.), iso-hexane, boiling-point 142° F. (61° C.). "Spirit," of 0.685 to 0.705 specific gravity, is mostly heptane (C7H16), boiling-point 207.5° F. (97.5° C.), and octane (C8H18), boiling-point 257° F. (125° C.).
The pentane vapour is 2.5 times heavier than air, while the "spirit" vapour is 3.4 times heavier than air. The petrol is usually purified by treatment successively with sulphuric acid and a solution of caustic soda, and then washed with water. The name " petrol " is registered as a trade mark, and can only be used by the one firm owning same, and consequently this spirit is generally advertised as "motor spirit," although the name petrol is more usually employed in speaking of it. In this book the expression "petrol" may be taken as referring to the spirit usually sold for motor work.
Prof. Boverton Redwood (the accepted authority on petroleum) has found that
100 vols. air at 32° F. will retain 10.7 % gasoline vapour of 0.65 sp. gr. ,, „ 50° F. ,, 17.5 % ,, „ „
68° F. „ 27.0%
while air charged with 735 grams gasoline vapour per cubic foot will give a light equal to i6j candle-power at 3^ cubic feet per hour, when burned in a i5-hole Argand burner, or
VAPOUR CARRIED BY AIR.
equal to, say, 23.6 candle-power, when consumed at the standard rate at which all gases are tested, namely, 5 cubic feet per hour.
While the above table refers to the quantity of vapour able to be carried by a given quantity of air, there is another point of view which Dr Redwood observed, and that is the amount of liquid which is absorbable by 100 volumes of air at 60° F., which is as follows : —
With gasoline, of 0.639 specific gravity, 0.59 volume liquid absorbed
by loo volumes air. With petroleum spirit, 0.679 specific gravity, o. 18 volume liquid absorbed
by 100 volumes air. With petroleum spirit, 0.700 specific gravity, o. 17 volume liquid absorbed
by 100 volumes air.
Now, it is clear from the first table that if a certain volume of air, which has been passed over gasoline at a high temperature, and has absorbed all the gasoline it can take up, and is afterwards reduced to a lower temperature, the air is not capable of carrying so much of the vapour, and therefore some will be condensed and deposited in the pipes or other cold part of the apparatus. It is this fact which hindered the extended use of the earlier types of plant, wherein the gas made was required to be as rich as possible, as the burners used were all of the luminous kind, either of the flat-flame or Argand type. The introduction, however, of the Welsbach mantle rendered it unnecessary to make any other than a heating gas, and some plants were designed which made such a gas, which was very near the explosion point, and as the arrangements for carburetting or gasifying the air were not of the best, the gas was variable in quality, and not infrequently explosions, more or less acute, were experienced.
Where a very small quantity of vapour only, say 1.8 per cent., is allowed to mix with the air a gas is made
i6 PETROL AIR-GAS.
which is inflammable but practically non-explosive, and such gas contains all the air required for its complete combustion. In this respect it differs from the ordinary coal-gas, which requires to take from the atmosphere sur- rounding the flame about 5.6 times its bulk of air to ensure it being properly consumed. In the petrol gas above mentioned, all the air is passed with the gas along the pipes. When rather more than 2 per cent, of vapour, say 2.15 per cent., is present, an explosive mixture is formed, and this is the case up to between 4 and 5 per cent, of the vapour when the limit of the explosive nature is reached and a greater proportion of vapour to air becomes again inflammable only. In the petrol motor the mixture at the time of the explosion will probably vary from 1.5 per cent, to 5 per cent., the weaker mixture only firing when there is a good compression. It must be distinctly understood that although the gas con- taining over 5 per cent, of petrol vapour is not of itself explosive, if it be allowed to escape into an apartment and there to mix with the air, it will then possibly attain the necessary proportion of air to become explosive, and will in fact explode if a light is brought near such mixture. In this way the danger is always present when a rich gas, whether coal or petrol gas, is being supplied.
The public have now become so used to the ordinary coal-gas, and know its dangers, that little fear need be felt of such danger, as proper precautions will generally be taken to avoid risk of accidents. However, it is necessary to point out clearly that all petrol gas is not non-explosive, and while so many firms are advertising the safety of their petrol gas, it must be clearly understood that a petrol gas can be dangerous if more than a certain quantity of vapour is allowed to mix with the air.
It is one of the accepted facts in science, that whatever gives off heat must have first absorbed heat from somewhere,
HEAT FROM 1 LB. PETROL. 17
and there is no doubt that considerable heat has been used in the formation of petrol from its elements, which is stored up in it as chemical energy. One pound of petrol will give up when completely consumed with a sufficient quantity of air from 19,000 to 30,000 British thermal units, or to put it in a way more easily understood by the lay mind, i gallon of petrol will give out enough heat to raise from 90 to 140 gallons of water from 60° F. to boiling-point (212° R), according to its specific gravity. On the other hand, when any solid body, such as petrol, is vaporised, there is always a certain amount of heat absorbed, and to show this amount of heat absorbed (or rendered latent) during the vaporisation of petrol, if 2 gallons are contained in a vaporiser and i of these gallons is gasified, the remaining gallon will be reduced to about 12° F., or 20 degrees of frost, when the hydrocarbon will no longer give off gas until heat has been absorbed by it from the atmosphere.
Petrol, unlike alcohol, which can be extinguished by water, is very difficult to put out when lighted, and for this purpose a mat, or blanket, or rug, or in fact anything which will exclude the air from the flame, is the best extinguisher. Water, being heavier than petrol, only causes it to spread over a larger area. It should be remembered that, should a petrol can get alight, by any mischance, the flame is all outside and not inside, because the flame can only live while oxygen is able to approach the carbon and hydrogen and to convert these elements into the compounds carbon dioxide and water (hydrogen and oxygen), and consequently there is no danger of explosion if the opening is closed, and this should be done as speedily as possible, before the heat melts the joints of the can and the spirit can spread over the ground and perhaps cause a serious conflagration.
There have been several cases of explosions due to the pouring of petrol down drains, when it has been carried
IS
PETROL AIR-GAS.
forward on the surface of the water and gradually formed an explosive mixture, which -has become ignited and caused serious damage by the sewer manholes being violently blown out. If waste petrol has to be disposed of, it should be poured over the soft soil of the garden, in an open part where it can evaporate and mix with the air until it forms a non-explosive mixture. Even here there is danger of fire for some time after the petrol has been distributed, if a light should be applied to the spot, especially if there is no wind to dissipate the vapour, which, being heavier than air, hangs about the spot where it has been deposited for some time. In fact, a train can be made, like gun- powder, to ignite a bonfire, at even so great a distance as 50 yards away, and when ignited at one end a flash and a dull report will follow, and the flame will rush along the train with great speed, especially if the grass or ground is wet, when the petrol cannot sink into the soil. The petrol will burn very much like the brandy poured around the Christmas pudding, but it would not be advis- able to substitute the former for the latter, as a possible taint might ensue, which would not be appreci- ated by the eater.
When considerable quantities of petrol are stored, it is not inadvis- able to have one or other of the chemical fire extinguishers about, although this should not be necessary if ordinary care be exercised. One of these,
FIG. i.— "New Era" Petrol Fire Extinguisher.
POURING PETROL.
which was carried by order of the Royal Automobile Club on all vehicles competing in the recent Commercial Motor Vehicles Trial, was the "New Era" Petrol Fire Ex- tinguisher, manufactured throughout in Great Britain by the Valor Company Ltd., near Aston Cross, Birmingham.
One source of danger is the spilling of petrol when filling tanks with the same, and this can be largely avoided by the use of the tins in the proper manner, which is perhaps the reverse of that ordinarily adopted. The tins are usually pro- vided with an air-vent tube, which is designed to allow the air to pass into the can to take the place of the petrol as it issues from it. These air-vents are only efficient when the can is held so that the nozzle is in the upper corner, not the lower, as is usually the fashion when pouring petrol. When the nozzle is uppermost it is obvious that the air can then enter through the vent and so prevent the gurgling and
FIG. 2.— Petrol Filler.
splashing of the spirit, and consequent waste, with its possible danger of fire.
The United Motor Industries Ltd., of 45 and 46 Poland
20 PETROL AIR-GAS.
Street, London, W., have designed a means of conveying petrol from the can to any tank, which, although primarily designed for motor-car work, could be employed for gas- making purposes with advantage. This arrangement con- sists of the use of a pump — the ordinary bicycle or motor tyre pump — to cause a pressure in the petrol can, and a flexible tube which is inserted into and through the plug to the bottom, and which tube can be carried to the tank to be rilled, so that on an air pressure being conveyed to the can, the petrol is forced through the tube to the tank without any spilling and consequent loss.
This represents a 40 gallon safe.
FIG. 3. — Tupholme's Spirit Safe.
Another piece of useful apparatus which might be em- ployed where petrol gas is in use is Tupholme's Spirit Safe, which is made of galvanised iron, and fitted with ventilators with "Davy" gauze. In this can be stored a number of tins, when in the event of their leaking, the spirit passes to a well below the door, made large enough to hold the same amount of loose spirit as is in the tins, thereby ensuring the non-escape of spirit from leaky tins. They are made to hold 10, 20, 30, or 50 tins.
It may be said that petrol cannot freeze at any natural
FROM PETROL. 21
frost we may be likely to experience in this country ;\ how- ever, by means of liquid air, it has been rendered solid. It is quite safe, therefore, to store petrol out of doors, without any fear that it will not be available when wanted.
From a given quantity of any hydrocarbon, such as petrol, only a given amount of heat can be obtained. It has already been pointed out that in the case of petrol of 0.722 specific gravity this equals 19,000 to 23,000 British thermal units per lb., and this amount of heat may be spread over a large quantity of gas, if much air is mixed with it, or it may be contracted into a small quantity of gas. Thus the amount made in cubic feet by any air-gas system does not of itself show the value of the arrangement, as, with the larger quantity made, more will be required to make the mantles equally white hot. This is not generally understood, and is a point which cannot be too well noted, as many makers, knowing the lack of general knowledge on the point, make a great matter that their machine will make so many more feet of gas from the gallon of petrol than that of some other maker.
One gallon of petrol will make, say, 200 cubic feet of rich gas, requiring some 1,700 cubic feet of air, partly delivered at the base of the burner, and partly around the flame, or it will make some 1,500 to 1,800 cubic feet of poor gas, containing sufficient air to support combustion, without any air being required to be taken from the atmosphere of the room. This is an important matter, as what the burner requires in the former case is the oxygen, which is the life- giving portion of the air, and the resultant gas, carbon dioxide, while not poisonous, is of no value to support existence, and the nitrogen (the other principal constituent of the air) remains, and is only a diluent. If the composition of the petrol vapour be 16 per cent, hydrogen, and 84 per cent, carbon, each cubic foot will require, for complete
22 PETROL AIR-GAS,
combustion, 1.76 cubic feet of oxygen, which it will be able to obtain from 8.4 cubic feet of air, and this quantity must, therefore, be mixed with the vapour, if the gas is to be self-burning, and able to burn without requiring any air from the surrounding atmosphere.
In the regulations as to the keeping and use of petroleum for the purposes of light locomotives the following paragraph occurs, and as this contains exceedingly good advice to any user of petrol, it has been thought advisable to insert a copy of it here : —
"In promulgating the following regulations relating to the keeping, conveyance, and use of petroleum in connection with light locomotives, the Secretary of State for the Home Department desires to direct public attention to the dangers that may arise from the careless use of the more volatile descriptions of petroleum, commonly known as petroleum spirit. Not only is the vapour therefrom, which is given off at ordinary temperatures, capable of being easily ignited, but it is also capable, when mixed with air, of forming an explosive atmosphere. It is, therefore, necessary, in dealing with and handling the spirit, to take strict precautions, by the employment of thoroughly sound and properly closed vessels, to prevent leakage of the spirit, and by avoiding the use of naked lights in dangerous proximity, to prevent the contact of any form of artificial light with the highly inflammable vapour which it is always evolving."
There is no doubt that, according to the "Petroleum Acts of 187 1- 188 1, "a license must be obtained for the storage of petrol, unless it is kept in separate glass, earthenware, or metal vessels, each of which contains not more than a pint, and is securely stoppered ; or that the aggregate amount kept, supposing the whole of the contents to be in bulk, does not exceed 3 gallons.
It is an anomaly that such a license must be obtained
LICENSE TO STORE PETROL. 23
when the petrol is required for gas-making purposes, while, if it be wanted for motor-car work, it can be stored without. It is to be hoped that the Legislature will see this, and alter the law accordingly in the near future. The obtaining of a license is not a very elaborate process, as all that is required is to make an application to the officer under the Petroleum Acts, who is appointed by the Local Authority. If the petrol be kept in other than the above-mentioned way, without a license, then it is liable to be forfeited, together with the vessel containing the same, and, in addition, the occupier of the place where such petrol is kept is liable to a penalty not exceeding £20 a day for each day during which such petrol is kept.
As regards places which may be likely to be licensed as storehouses under the Act, the following may be usefully noted: — Where a portion of the storehouse is used as a dwelling, or as a place where persons assemble, or where the storehouse forms part of, or is attached to another building, and where the intervening floor or partition is of an unsub- stantial, or highly inflammable character, or has an opening therein, or where the storehouse has not a separate entrance from the open air, distinct from any dwelling or building in which persons assemble, or where the storehouse is not thoroughly ventilated, then it may be likely that the inspector will not recommend the Local Authority to grant the license.
The vessels in which the petrol must be kept must bear the words, "Petroleum Spirit, highly inflammable," con- spicuously and indelibly stamped or marked thereon, or a metallic or enamelled label attached thereto, and shall be of a capacity not exceeding 2 gallons.
The makers see to this last regulation, and all the petrol cans supplied are of this capacity and are suitably stamped.
In no case is petroleum spirit kept wholly, or partly, for sale exempt from the necessity of a license.
CHAPTER IV.
Burners — Description of Same — Piping — Mantles.
THE theory of the ordinary flat-flame gas burner is that the carbon in the gas combines with the oxygen of the air to form carbon dioxide (CO2), and the hydrogen combines with the oxygen to form water vapour (H2O), — the former of these reactions taking place in two separate stages, in the first of which, the gas being in excess, the carbon is converted into minute particles which are rendered white-hot during the second stage. In the Bunsen burner, however, the gas and air are partly mixed before combustion takes place, and consequently the carbon never becomes separated, but the change to CO2 is carried out direct. The two gases, CO2 and H2O, are, however, still made, and the full heat developed, but no carbon deposit is possible if the mixture of air is properly proportioned. This, of course, refers to the richer gases, which require a large proportion of air to ensure proper combustion.
On a casual examination the burners used with the safety gas appear to be of the Bunsen type, but, on looking further into them, we see that the usual air-holes at the side are closed completely. This is because the gas is already supplied with all the oxygen necessary for its complete com- bustion, and in this respect resembles the blow-pipe burner, with its intense, though short flame.
The great increase in the light from a Welsbach mantle, when the heat of the flame is only slightly raised, has been recognised for some time in the high pressure coal-gas distri-
PETROL GAS FLAMES. 25
bution systems, and the same effect is gained, of an intense combustion, by the use of the petrolised air-gas, so that the mantle used need only be a small one ; a bijou size (which with coal-gas is generally considered capable of giving a light of 20 candles, with a consumption of i cubic foot) is said to give a light of 62.5 candles with the air-gas. Of course, a much greater quantity of the air-gas must be used, as not only the gas but the air used from the surrounding atmo- sphere, which would be taken in at the air-holes of the Bunsen burner, would have to be supplied through the burner proper. The flame is a solid one, and the combustion must necessarily be complete when the necessary and correct quantity of air is being supplied with the gas. This quantity of air, in the case of coal-gas of about 16 candle-power, equals some five to six times (5.6 is the average) the quantity of coal- gas being burned, but this is passed along with the petrol vapour in the modern air-gas machines, hence the necessity of larger pipes; in fact, no pipe under f- -inch bore should be used.
The heat from a given quantity of hydrocarbons, when completely burned, is constant, and is due to a definite chemical combination, which is known and calculable from the proportions of carbon and hydrogen present, so that from such combination only a certain amount of heat is obtain- able, no matter how the gas is consumed. This is frequently misunderstood by the general public, and the fact that a Bunsen burner is no hotter than a flat-flame burner, con- suming equal quantities of gas, is hardly believed. It is, however, a fact which cannot be controverted ; at the same time it is necessary to remember that the flame of a Bunsen burner may be allowed to touch the object to be heated without depositing carbon upon it, if it be kept sufficiently far above the burner as not to touch the inner cone, which should be of a green colour.
26 PETROL AIR-GAS.
The flat-flame burner, which was almost the only one used some ten or fifteen years ago, would deposit carbon upon any cool surface exposed to the direct action of the flame, because the carbon in the gas was not fully gasified when it touched the cooler object, and therefore was de- posited in the solid form. This can be immediately proved by holding, say, a plate in the flame of an ordinary gas burner.
Another point which is not generally understood regard- ing the gas flame is that the blue portion is really uncon- sumed gas. This also can be proved by the insertion into this part of the flame of one end of a small tube, and the ignition of the gas at the other end proves that the gas drawn up the tube is combustible by its burning when a light is applied. This is also exemplified when a wax match is used for lighting a cigarette or cigar, which is frequently held in the blue portion of the flame, in the mistaken idea that this is the hottest part of the flame (because the Bunsen flame is of a blue colour). When this is done, and the gas inhaled, the unconsumed gases are drawn into the system, and as they consist of carbon monoxide and other poisonous gases, they are distinctly injurious, so that this practice should certainly be discontinued.
The laying of the pipes for this gas, which is usually dried before delivery to the carburettor, does not require quite so much care as in the case of coal-gas, which is saturated according to the temperature with water vapour. There should be no deposit from petrol air-gas, and therefore the sagging in pipes will not be so likely to cause a stoppage through the accumulation of condensation in such places.
Inverted burners are not really necessary, as all that is wanted is an inverted pipe through which the gas and air can pass out to the mantle, with suitable fixings to attach
AIR FOR COMBUSTION. 27
the mantle, and with suitable gauzes to break up the flame. The advantage of not requiring any oxygen from the air is a great one, as this intaking of air with the ordinary coal- gas inverted burner has always been a trouble, as the products of combustion in rising have fouled the ingoing air, and thus the proper proportion of oxygen has not entered and mixed with the gas, and a smoky flame has been the result. Although it is quite easy to utilise the inverted burner, several firms are making and supplying a special burner for this new gas only, and several arrange- ments of the gauzes have been patented to ensure perfect combustion.
It will be easily understood that, as all the air necessary for combustion is combined with the gas, no holes are required at the base of the burner as in the usual burners employed with incandescent lights, so that if the ordinary burners are used, these holes require almost, if not quite, closing by means of a band of sheet metal surrounding the holes. In that case, ordinary Kern Welsbach burners serve admirably for the purpose.
The fact that no oxygen is taken from the atmosphere of the room to support the combustion of the gas is a most important matter, especially in a small or badly ventilated and low-ceilinged room, such as is frequently found in the old country houses where the new petrol air-gas will be largely required.
With ordinary coal-gas a higher pressure of gas is an advantage, as it causes a more intimate admixture of the gas and air, and also draws in a greater quantity of air at the bottom holes of the Bunsen burner, thus approximating more nearly to the petrol air-gas burner, with its full quantity of air required for combustion. With petrol air- gas, this pressure is not so advantageous, as there is no induction of air required, and the pressure of the gas is
28 PETROL AIR-GAS.
brought to the inside of the mantle. Thus a pressure which will ensure the passage of the gas to the burner throughout the supply pipes is generally considered sufficient, or say 2 inches of water pressure, and the flame obtained is a very hot one, owing to the complete combustion in a reduced area.
This brings us to another point in the question of burning gas, which is that a quantity of gas of a given composition can only give out a certain quantity of heat, no matter how it is consumed, provided always that it is completely combusted. The difference between one flame and another in a heating burner is a matter of size. The hotter the flame the smaller the size, so that in effect the heat is concentrated into a smaller bulk, and is thus more intense. This intensity of heat will give a greatly increased light from the mantle. A richer mixture than is proper with the petrol air-gas will not give a proper light at the burner, as it will become illuminating, and there will be soot deposited on the mantle.
To show the advantage of keeping a mantle clean and free from dust, it may be mentioned that a mantle can be rendered non-illuminating if dipped in ink and thus coated with an iron oxide. This accounts for the fact that a mantle, which has been upon a burner unused during the summer, and accumulating dust, fails to give a satisfactory light when tried as the days get shorter.
All the instructions usually given regarding the use of mantles for coal-gas should also be followed with petrol air-gas. Such as seeing that the stalk or mantle rod is upright, so that the mantle exactly fits and envelops the flame. The burner also should be fixed perfectly upright. If a Kern burner is being used, the serrated wheel on top must be exactly central and lie evenly, perfectly flush with the top of the burner, otherwise the flame will be one-sided
WELSBACH C0:s INSTRUCTIONS. 29
and cause the mantle to shrink more on one side than on the other. The consequence is that the mantle will be out of shape after a few hours' burning.
The following instructions issued with each mantle by the Welsbach Company may prove useful and are therefore inserted here :—
" Do not pinch head of mantle between ringer and thumb."
" Remove burner head, fit fork. Hold mantle in palm of left hand, pass mantle gently over burner head until fork catches up the loop. Be careful that fork does not pierce mantle. Fit chimney before burning off mantle. Replace burner head on Bunsen tube, and before turning on the gas, light mantle from skirt and burn off toughening. Turn gas half on and hold light over chimney till gas ignites. Then turn gas full on, the lamp being ready for use. Bunsen tube should be blown through and gauze brushed periodically to remove dust."
The making of an incandescent mantle may be described shortly as follows. Cotton or ramie fibre (made from an Indian nettle) is knitted in a stocking machine into a cylindrical form about 2 inches in diameter and in a continuous length, and is then washed in hydrochloric acid and in ammonia to clean it and free it from all impurities. It is then placed in a liquid of the metallic oxide of thorium (99 per cent.) and cerium (i per cent.). Thorium is the light-giving rare earth, and cerium helps to make the colour of the flame warm and pleasant. The mantles are then squeezed and left to dry. The upper ends are sewn, so as to hang, with asbestos thread and stretched over a cone to shape them. When heat is applied the cotton or ramie fabric is burnt away. They are then subjected to a high temperature Bunsen flame to harden them and are then of course only ashes of thorium, and
30 PETROL AIR- GAS.
are very brittle and would not stand carriage, so they are dipped in a bath of soluble gun-cotton dissolved in good alcohol and acetone with castor oil and shellac. Before the mantle can be used on the burner this coating must be burned off.
Where petrol is being passed through pipes great care must be taken that all joints in same are sound, as this liquid is very liable to creep and will pass through a crack which will not allow water to leak through. In fact funnels are supplied with a very fine meshed gauze in them which will allow the petrol to pass through, but which retains the water, if any, accompanying it. Where a joint is required, which can be disconnected at will, this should always be a ground one, without washers, and of a good class and finish, or a leak will soon result with possible danger of explosion.
Where a leak has appeared, shellac may be used to temporarily repair same, or a putty made of French chalk worked up with silicate of soda and applied to the leaky place. This mixture, when made up of the consistency of paint, may also be used for the threads of any pipes to be jointed in the same way as red lead paint is used for ordinary pipe jointing, and the joint is then petrol tight, when with red lead paint it would in time be washed out by the thinning of the linseed oil in the ordinary joint.
CHAPTER V.
General Principles of Parts of Plants — Motive-Power Meters — Weight- driven Plants — Root's Blowers — Hot-Air Engines — Pelton Water- Wheels.
WHAT is termed in the gas industry a "Motive-Power Meter " is frequently used in machines for making air-gas. These consist of an ordinary wet-meter drum, which is made to revolve by a system of gearing connecting a barrel with the drum of the meter. This barrel has wound around it a rope, to the other end of which is attached a weight after the rope has been carried over a pulley, and the falling of this weight causes the drum to revolve and draw in air. In the ordinary way, the pressure of the gas upon the partitions of the meter-drum cause it to revolve, but if the drum is revolved by outside power faster than the gas is driving it, then it acts as an exhauster, and draws in the gas and expels it at a higher pressure on the outlet than the inlet.
The action of a meter is so little understood that one may be pardoned for referring to it here, as a proper under- standing of its working will go a long way to keeping it in order when in use. The wet meter consists of a cylindrical case containing a drum, which is divided by cross partitions into three or four chambers into each of which the gas enters in turn ; the pressure of the gas causes the drum to revolve, and the gas from the chamber which has been filled just previously, to leave by an opening on the further side from that by which it was filled, water, which is always filled nto the case, until it is above the level of the centre of the
32 PETROL AIR-GAS.
drum, forming a seal so that the gas cannot escape direct into this outlet. The gas then enters a hooded cover, to which each of the compartments has a connection, and passes into that whose entrance is above the water ; the exit to this compartment is then below the level of the water, and will be so until the revolving of the drum, by the pressure of the entering gas, first carries the entrance below the water surface, and then the outlet comes above the water line, and the gas can flow out. The pressure of the gas entering one compartment expels the gas from the one previously filled. In this way the entrance and the exit passage of a compartment are never open together, unless the level of the water is allowed to get below the proper height.
It is perhaps needless to enter into the arrangements which exist in an ordinary consumer's meter, to prevent fraud and to preserve the accuracy of the meter up to the standard required by Government, but it may be said that there is a species of ball-cock which shuts off the gas when the water has fallen too low, and the gas could pass through the meter without causing the drum to re- volve ; while, on the other hand, there is an overflow provided, so that too much water cannot be put in. These parts, however, do not usually form part of the "motive- power" meter, although the water level must be kept up, or no air will be drawn in, and consequently the gas will not be made. The weight fastened to the spindle will also run rapidly down, if there is no water in the meter or enough to ensure a proper seal, which would be more than the pressure at which the air is delivered, say 2 inches.
Where weights are used for obtaining the power to com- press the air and pass it through the machines, a height is required for the drop of such weights of from 20 to 30 feet, according to the size of the apparatus. A well or pit can
FRICTION OF PULLEYS. 33
be dug in the ground, which will allow the weight to have the required fall, if this is not available above ground, but this pit should be drained, or condensation may occur, and the pit become filled with water, when the effect of the weights upon the moving parts of the apparatus will be reduced and the plant possibly rendered unsatisfactory. Usually, however, a high wall can be found upon which a bracket can be fixed, or the fastening of the pulley made to the overhanging eaves of a house, so that the desired fall can be given without the necessity of a pit.
When a rope is passed around a number of sheaves in blocks, there is considerable friction due to stiffness of the ropes and the friction of the sheaves, and to allow for this one-eighth of the weight additional must be added to the weight for each sheave in use. Thus, if a power of 20 Ibs. is required to work the machine, and two five-sheave blocks are used to give the necessary time through which the full fall is to take place, then, beside the 200 Ibs. required to give this power without counting the friction, a further one- and-a-quarter times the 200 Ibs. will be wanted to overcome such friction, or a total weight of 450 Ibs. will be required. This is the rule adopted in the Royal Artillery.
A type of blower which is used in a good many of the plants, where the air pressure is obtained by a mechanically driven method, is what has been recently known as " Root's " Blower. This is made in a large number of sizes, and will give a steady pressure of air if the pressure required is not too great. They work up to 9 or 10 inches quite satis- factorily, and, as the pressure required by the petrol plants is only about 2 inches, it will be seen that they will serve the purpose in such machines. This blower is sometimes called the " two eights," owing to the shape of the feathers or fans forming the moving parts of the apparatus. The case is oval-shaped and provided with an inlet and outlet
c
34 PETROL AIR-GAS.
on opposite sides of same, and the two figure eights are enclosed within and have their axles passing through bear- ings, each with a toothed wheel on the outside, gearing into each other. The pulley or driving wheel is fixed to one of the axles, and the other is driven at the same speed by means of the toothed wheels, so that the speed is kept the same, and when the one " eight " is horizontal, the other is then vertical, with the end of the former closely fitting into the waist of the latter. The case fits the " eights " so that their ends rub through half a circle each, the space between being straight. These blowers require lubrication from time to time with a fairly thick grease, so as to keep the " eights " up to and tight against the case. This is one of the objec- tions to this form of blower, that it has no possibility of adjustment when worn, and, as it is constantly rubbing, the surfaces in time must get slightly apart.
Hot-air engines, which are frequently used to drive the blower or compressor, are capable of giving the small amount of power required when worked by a heating burner. They act by the expansion of the air in the cylinder, due to the heat derived from the burner. The air is generally cooled on entering by passing through a water-jacketed vessel, so as to give the maximum amount of expansion. When start- ing the plants worked by such engines, the motor has to be turned by hand for a time until the air-gas is being produced. Then the burner under the engine can be lighted, and the engine will start to work itself in about two minutes. The burner should not be lighted under the engine, but should be provided with a swivel arm, which will allow of its being drawn out, so that no unlighted gas may collect under the engine, as this may have become too rich in quality and cause an explosion.
These engines, and also the compressors, require a little attention in the way of cleaning and oiling, but this is not
PELTON WHEELS. 35
more than can easily be undertaken by any one without special training. Such engines require the employment of a light in the gas-making room, and should there be a leakage of petrol, or some of it get spilled when filling the tank, then there is a possibility of an explosion with such a light. Therefore the petrol tank should be outside the room where the hot-air engine is working. Again, this light must be kept burning ready for any lighting, or the gas actuating the engine must be lighted in time for use, and extinguished when the gas is no longer required, if gas is to be saved.
Where a head of water is obtainable, the power for drawing in the air under pressure may be had from a water motor on the Pelton principle ; this may come either from the town's water supply or other source, where a pressure of 15 Ibs. per square inch (or from 34 to 35 feet head) and upwards can be obtained, when a most economical means for small power is to hand.
The Pelton wheel consists of a wheel, truly turned and balanced, with a series of buckets fixed around its circum- ference. The water is projected from one or more nozzles set at an exact angle to the buckets, and this angle should not be altered as the power will be at once reduced, the makers assuring themselves that they have found the angle that suited the form of bucket used.
To obtain the highest results the speed of the wheel must be proportioned to the pressure of water in the supply pipe when the motor is running, and a pressure gauge should be used to obtain this. The makers issue a table showing the speed most economical at various pressures for each size of motor. The supply pipe should be of ample size, so as to reduce the loss of pressure from friction to a minimum. A smaller quantity of water is used when this is done, as the full pressure is brought to the wheel, and can be converted
36 PETROL AIR-GAS.
into work. Such motors should be fitted with double nozzles, so that, when working only slowly, the one can be shut off and water in this way saved, as the full pressure is brought to the single jet, instead of reducing the pressure on both jets with the larger quantity of water.
An arrangement on a small balance-holder can be used to close off the water from the wheel, when the holder is full,
FIG. 4. — Pelton Wheel.
and to open it again when the holder falls a certain distance. It is best to allow the holder to travel a certain distance before the water is again turned on, as then the pressures will be more even. The petrol supply can be obtained in the proper proportions by the use of a small pump fitted to the axle of the water motor, to which also is attached the blower or fan.
If preferred a system of holders can be used instead
WATER WHEELS. 37
of the blower. The holder would require to be moved up and down by any suitable gearing from the water wheel, and preferably the tank, containing the holder, should be made concentric, or in other words with a false centre, so that the quantity of water surface offered to the gas and air is as small as possible. This is necessary, because, on the move- ment of the holder up and down, the pressure varies from suction at one moment to pressure at another, and the water has first to be moved before any air is drawn in or expelled. The usual balance-holder should be used to ensure even pressure of the resulting gas.
These Pelton water motors can be purchased to give from 0.03 horse-power with 40 feet head to 0.23 horse-power with 1 60 feet head, up to any required power and head, and cost only some £2. los. each for the size mentioned above. While as regards the water used at 60 Ibs. pressure, each horse-power requires 5 cubic feet of water per minute, so that i cubic foot per minute, in the smallest machine (6 inches diameter), gives one-fifth horse-power, while 21.9 cubic feet per minute gives 4.35 horse-power in the larger size of 26 inches diameter.
When sending inquiries to makers of turbines or water wheels, the following particulars should be given : —
1. Quantity of water in cubic feet per minute, or sectional area and velocity of the stream.
2. The height from surface of head- water to the surface of tail-water.
3. Whether turbine is placed in an open flume or in an iron case ; if the latter, whether vertical or horizontal arrangement.
4. Kind of machinery to be driven.
5. Full particulars of buildings, gearing, and position of turbine.
CHAPTER VI.
Descriptions of Various Plants.
MULLER'S patent "Alpha" gas-making machine was intro- duced fully thirty years ago, and has been supplied in many places since that time. The apparatus consists of a revolving drum, driven by weights, an elevator to raise the gasoline, and trays to form a carburettor. The air is drawn in by the drum and made to pass over several trays,
automatically supplied with gasoline by the elevator, which brings it up from a reservoir which forms the base of the machine. The air, thus carburetted and saturated with the vapour, passes out as gas, which can be lighted and extinguished in exactly the same way as coal-gas and used in flat- flame, Argand, incandes- cent, or heating burners, the only labour necessary being to wind up the weights and replenish the reservoir with gasoline ; and so long as they are kept in a building with a temperature of 50° to 60° F. no heat is required. The makers state that from tests they have made, as compared with coal-gas, 1,000 cubic feet of 1 6 candle-power, passing through a burner consuming 5 feet an hour for 200 hours, will consume 2\ gallons of gasoline,
FIG. 5.— Muller's "Alpha" Machine.
OF
SUN" GAS- MA KING MACHINE.
39
and taking this at say is. 8d. per gallon would mean about 45. 2d. per 1,000 cubic feet. As showing the lasting of these machines, some sent out over twenty-five years ago are still in use and doing good service. The machines are automatic ; whatever the number of lights there may be burning, if all are extinguished except one, the machine will continue to make gas, but only sufficient for the one remaining light, and when that is put out the operation will stop. There is consequently no danger of escape.
FIG. 6. — Hearson's "Sun" Machine.
Hearson's " Sun " gas-making machine, which was a very early type of the rich gas-making plant, consists essentially of a motive power drum revolving in the gasoline by means of weights pulling on a cord which surrounds a barrel connected to the drum. The turning of the drum draws air in over the gasoline, when it absorbs the vapour ; the constant turning of the drum and consequent churning
40 PETROL AIR-GAS,
of the gasoline causes the complete vaporisation of the petrol. Where this is not the case, the air carries off the lighter proportions first, and leaves a large residuum of useless spirit. The use of the gasoline itself, and not water, for the drum to revolve in, has also the important advantage that it cannot freeze either in consequence of cold weather or the cold due to evaporation of the spirit used ; there is also no possibility of moisture being carried forward to be deposited in the pipes and perhaps cause them to become choked, or partially so, when blinking lights would be the result. The gas is made as fast as it is required and no faster, therefore there is never a large quantity on the premises and an independent gasholder is not needed.
Whenever a constant supply of water at a sufficient head is available, the machine can be driven by an auto- matic hydraulic motor, and with such an arrangement the machine requires no attention beyond supplying it with gasoline, and when the gas is not burning no water is expended. As regards space required, a building 12 feet square is sufficient for a machine of 120 lights, including storage for a three months' supply of gasoline. The cost of the gas works out at about 6s. 6d. per 1,000 cubic feet, but it must be remembered that it is much richer than ordinary coal-gas. It will be noticed that in both the "Alpha " and "Sun" plants gasoline is mentioned — this is because this spirit is necessary and not petrol.
The writer, as far back as January 1897, was shown by Mr P. B. Watson, the then manager of the gas-works at Falkirk, North Britain, what was probably the first petrol safety gas machine, and which that gentleman had patented. The invention consisted primarily of a scrubber or cylin- drical vessel, having within it a number of trays of per- forated material made of such shape as to permit of the
NOT KIN" LAMP. 41
thorough saturation of the absorbent material placed upon them. The hydrocarbon liquid was brought .to the top of this scrubber, and run in through a pipe at the top. Air was passed through the scrubber from the lower end, and in its passage took up some of the vapour of the hydro- carbon liquid, and, when expelled at the top end, was gasified sufficiently to allow it to burn with either a blue or an intensely white flame or any intermediate colour as required, so as to give either a heating or lighting flame. The air was passed in from a motive power meter, which only worked when the gas from the outlet of the scrubber was being used. On the same spindle as the drum was fixed a wheel which revolved with the drum, carrying on its periphery a series of cups or buckets ; these cups lifted up from a receptacle or tank a quantity of the hydrocarbon liquid, and when they arrived at the upper part of their travel, they emptied this liquid into a hopper, from the bottom of which the liquid was conveyed by gravity to the scrubber. The buckets were made of such a shape that, by setting them at varying angles, they could be made to lift any desired quantity of the liquid, and also that they could lift the said quantity independent of any variation in the quantity of liquid in the tank. Unfortunately Mr Watson did not pursue his investigation to a sufficient length, and the patent has now expired.
What was known as the " Notkin " lamp was also an early type of petrol-gas machine. The earliest of these con- tained a vessel filled with plaster of Paris and keiselghur, which formed a porous block, capable of absorbing a con- siderable quantity of a spirit which was not satisfactory if of more than 0.7 specific gravity. The block contained a number of holes right through it, and through which the air passed, becoming carburetted with the petrol vapour, and therefore heavier than air, and passed down a pipe to
PETROL ATR-GAS.
the burner, which was below the vessel containing the absorbent block.
The burner at first was of the Argand type, but later one of the Bunsen order was substituted for the purpose of heating a mantle, a long chimney causing a draught to obtain the necessary primary air for the burner. This long chimney and induced draught was afterwards made to draw not only the air, but also the petrol vapour from the con- tainer, then placed under the burner, and so supply the
heating flame for the _ ,, mantle. This was the
invention of Dr John
Marshall, F.R.S., of
Edinburgh, and some
others.
The improved lamp,
known as the " Petro-
lite," consists of a con- tainer, technically called
a carburettor, which is
made of metal, and is
partially filled with a
porous material which is
saturated (as required) with petrol or motor spirit. Paraffin oil of any grade will not answer. The porous material in the container is not affected by the liquid, and does not require renewal. As there is no petroleum spirit in a liquid form in the container there is no danger of fire, and should the lamp be overturned the light simply goes out, as there is then no draught from the chimney, and there is no oil to spoil carpets, &c. Many attempts have been made to cause mishaps, but they have all been unsuccessful. The lamps give a light of some 50 candle-power.
FIG. 7. The Lamp Body.
FIG. 8.— The "Petrolite" Container.
"PETROLfTE" LAMP, 43
The method of filling and lighting these lamps is very simple, and is as follows : — Remove the perforated cover, turn regulating lever to left side and pour petrol into centre tube of burner until liquid appears at top of outer tube of burner; leave for one minute and return all unabsorbed petrol into the can, and shake out any remaining drops. Turn regulating lever to right side and replace perforated top. Then, by the insertion of a match in the opening of the burner gallery, a slight draught is caused in the chimney,
sufficient to produce a r „..,....„ , ,
"^ suction in the inner burner tube. The cold air thus drawn into the '^fnMl^fe^l lamp has to make its way through the per- forations of the porous material saturated with petrol. During its pas- sage the air is being carburetted with vapour, and this diluted gas, •
FIG. 9 While bdng drawn Up FlG- I0-
The Burne/Tube. the burner tube, meets The"Petrolite"
on its way with a further Burner.
supply of cold air from the outside. Both are automatically mixed in the exact proportion to give a hot Bunsen flame.
The evaporation of the petrol is thus caused, not by heat, but by a draught of cold air through the container, and the lamp body is colder than the surrounding air.
The writer was one of a Committee appointed by the Royal Scottish Society of Arts to report on this invention, and who found its efficiency in round numbers to be i gram per candle hour, to give a mean candle-power of about 40 to 45. Although, to get the greatest lighting effect
44 PETROL AIR-GAS.
from the petrol, a double system of regulating the vapour and air would be necessary, the arrangement with a single lever obtains a sufficiently good result with obviously many advantages for household use, and from tests they made this has evidently been most carefully calculated. The regulation is very simple.
Mr Gillie patented an arrangement for using compressed air with this apparatus, which he obtained by means of weights and pulleys, and in this way he secured a higher candle-power from the same consumption of petrol. The apparatus consisted of a drum, round which the rope from the pulley and weight was wound, and which turned owing to the pull of the weight. This turning was multiplied by suitable gearing, and finally served to raise and lower two double-acting gasholders which drew in and expelled air through two specially devised valve chambers, so that on the expulsion of the air it was driven into a small gasholder. To this was attached a brake, so that when no air was being used the brake prevented the turning of the barrel by the weight, but when the holder fell, the brake was released, and the barrel turned and worked the gasholders until the small one was again full, when the brake was once more brought into operation. A further addition of Mr Gillie's was to supply petrol to the container by means 01 a small pump worked by the same levers as actuated the gasholders, and, as these worked in accordance with the air required, the petrol was supplied exactly as it was needed.
The " Carmien " portable gas consists of a tank, con- taining petrol, fixed on the roof of the house or outside the window-sill of an upper room — the higher it is placed the better, but 5 or 6 feet above the light will suffice. The tank is connected to the patent burner by a hollow copper tube, about the size of a knitting needle, and through this tube the liquid petrol passes to the burner, where it is vaporised,
FIG. ii.— "Carmien" Burner.
PETROL AIR-GAS.
and burning with a blue flame of the Bunsen order, it serves admirably to render a mantle incandescent, and a light said to be of fully 70 candle-power is obtained. One tank will serve for any number of lights, a 3 mm. main being large enough to supply up to fifty or sixty burners. The very thin tubes can be bent almost the same as wires, and lend themselves to easy laying, and do not disfigure the walls, &c. This method was introduced in 1902, and is largely used in France and England.
The " Invetrol " gas light is on something of the same lines, but uses an inverted burner, by which the Company claim they can give 100 to 1 20 hours of light of 70 to 80 candle-power per gallon of petrol. The burner has to be started with a methylated spirit flame with an asbestos square, which operation takes about one minute, and once the vaporiser is made hot the Bunsen flame in the mantle keeps it hot. The outlet for the petrol at each burner is so small that it takes at least 100 hours for i gallon of petrol to be vaporised and burnt. FIG. 12. Once started it burns steadily and
" Invetrol " Light. continuously. The tank in this case is not necessarily outside the building, but may be an ornamental container hanging on the wall or from the ceiling. This container should only be filled in the open air, away from any light.
" PITNER-INVETROL" PLANT. 47
In the Pitner-Invetrol system, which is a later type of the plant just described, the fluid is stored outside the premises in a specially constructed tank. A seamless brass tube about an eighth of an inch in diameter connects the tank through this tubing to the different lights in a fluid state, by a pres- sure of 10 Ibs. of air pressure, which is pumped into the tank only after each filling (twelve to fifteen strokes of the pump are sufficient). This tubing will supply anything up to thirty lights, and can be carried comparatively unseen along the ceiling of a room, thus avoiding the use of the ordinary and larger gas-piping and electric casing.
The fluid runs across the generator, which has been previously warmed by a lighting torch. The heat converts the petrol into gas, which is directed downwards to the base of the light, automatically mixes with the air, and is dis- charged through a specially constructed mantle. When ignited it burns with a white light, and the heat of the light itself, on the generator above, is sufficient to maintain the further conversion of the fluid into fresh gas.
In the apparatus which is being manufactured by the Non-Explosive Gas Co. Ltd., there is a hot air motor, cooled by a current of cold air being passed around the jacket, which drives a rotary pump or blower, and draws in a sufficient quantity of air to provide 98 per cent, of that substance, as compared with only 2 per cent, or rather less, of petrol vapour. The carburettor, made of cast iron, con- sists of screens of very fine wire gauze and has no moving parts. The correct mixture is not dependent upon the regular working of the motor, but is obtained by the use of the meter which controls the supply of air, and a correct mixture can thus be regularly expected. The petrol tank is hermetically sealed, which adds to the safety. The hot air engine, which is driven by the jet of gas underneath it, which gas is supplied by the apparatus itself, is automatically
PETROL AIR-GAS.
controlled, so that it slows down when only a small amount of gas is being made. The air passes from the blower to the jacket of the hot air engine, next to the carburettor, and thence to the inlet of the meter, which is of the ordinary wet type, and thence to the balance-holder, which regulates the speed of the engine. The gas is stable, as has been shown by the fixing of the machine 600 feet away from the burners, with- out any deposit being found in the intervening pipes. The carburettor does not require heating, as the very small quantity of petrol used is quite easily evaporated by the large quan- tity of air, i gallon of petrol serving for making about 1,000 cubic feet of gas. The small quantity of hydro- carbon vapour makes the gas non-explosive, so that it will only burn in a Bunsen burner, having a fine gauze near the outlet, when it gives a blue flame.
The " Praed " patent safety gas plant consists of a small hot air motor A, which is caused to work by a Bunsen burner beneath it, this burner using a small proportion of the safety gas that the plant makes ; an air propeller B, of a simple kind, working in a bath of paraffin (which is used because it will not freeze in cold weather). This propeller
FIG. 13. — The Non-Explosive Gas Co.'s Plant.
PR A ED" SAFETY PLANT.
49
furnishes a volume of air when working at a slow speed, is positive and noiseless in action. When the number of lights is not that of the full power of the machine, air (not gas) blows to waste through a spindle valve on the air com- pressor. A mixing or carburetting chamber D, where the air and spirit meet to form the gas, is provided ; from this chamber the gas goes direct to the gasholder, needing no
to GasHolde.
FIG. 14.— The "Praed" Safety Plant.
purifying or other treatment. The hot air motor, besides actuating the air propeller, also works a small petrol pump c, so that the speed of each is proportionate; the pump draws petrol from the tank E, where it is stored, and the petrol can be poured in through the tube and funnel F, which can be carried outside the building, there is then no opening indoors where petrol can escape, nor need it be taken into the building at all. The gasholders supplied with
50 PETROL AIR-GAS.
the plants are small, that for the No. 2 (twenty-five lights) being 3 feet high by 16 inches diameter. If sufficient gas to last any period of time is desired, without running the machine during that time, a larger gasholder can be obtained, anything from 25 to 500 cubic feet capacity, according to the requirements or the magnitude of the job. This also is to be recommended when, say, a forty-five light plant is to be used for, say, sixty lights, as the machine can be making a store of gas during the day for burning with or without the aid of the machine at night. The percentage of petrol vapour in Praed gas is higher than some of the other plants claiming a greater make per gallon, but the gas is thereby richer, and ordinary Welsbach Kern burners may be used with it, with the addition of a collar on the mixing tube of the burner to reduce the air supply at the air holes to a very small quantity. This is an advantage over those plants requiring special burners.
The " Eos " gas apparatus consists of a generator or base, and a gasholder or superstructure. In the base is a winged partition drum, which, when revolved, stirs up the water in the base, and at the same time draws in a quantity of air, the water thus becoming partially aerated. A wire rope supporting a weight is wound upon a drum on the same spindle as the partition drum which it moves. In a separate compartment in the superstructure is the reservoir of petrol, in which is a dipping gear. This is also revolved by the drum, a steel chain connecting the two. At every revolu- tion of the dipping gear a certain measured quantity of petrol is introduced into the base, where it is made to combine with the air, forming the gas, which is then forced into the gasholder above. Thus only a measured quantity of the petrol is introduced into the air-chamber. The "Eos" apparatus requires to be wound up about twice a week, and to be charged with petrol every month or two. A small
EOS" GAS APPARATUS.
FIG. 15. — "Eos" Gas Apparatus — Weight-Driven Type up to 50 Burners.
52 PETROL AIR-GAS.
hand pump is provided for pumping the petrol into the receptacle. The proportions of air and petrol vapour which the makers prefer is 95 per cent, of air to 5 per cent, of petrol vapour ; this, of course, necessitates the use of a certain quantity of air around the burner to ensure complete combustion. It is stated that i gallon of petrol will make 860 cubic feet of gas with this machine, and the special burners consume about 7 feet per hour. This is one of the few plants that employ what is termed wet carburation, as the air is allowed to freely pass over the water ; this, it is claimed, keeps the temperature of the air more constant. The quantity of petrol admitted can be varied while the machine is working in the event of a variation in the quality of the petrol.
The machine supplied by Safety Light Ltd. is made under the De Laitte and Elwell-Smith patents, and is worked without the use of a hot-air engine, which, if the light is to be ready for use at any time, must be kept running con- stantly. The carburetting is effected cold without heating the air by a flame. The gas produced in the carburettor is put under pressure by a motive power drum and driven through the piping into the gasholder, which works a pressure regulator. The latter is controlled by a brake, so regulated as to stop the movement of the drum as soon as the gasholder is full. The motive power required by the drum is not large, and the cheapest and simplest method of driving is by means of a weight, fitted preferably with an electric bell to give warning when the weight is fully wound up or nearly run down. An alternative method of providing the necessary power is by using a water motor of the Keith pressure-raising type, which can be worked off an ordinary house supply, when air is drawn in by it and compressed. The quantity of water used is small, as with 30 Ibs. pressure, 50 gallons per night is sufficient for a seventy lights installa-
SAFETY LIGHT CO.'S PLANT. 53
tion of about 40 candle-power. The water used can after- wards be used for washing or other purposes if desired. Where electricity is obtainable the current can be used to drive an electric motor, which can be started and stopped
FIG. 1 6.— Safety Light Co.'s Weight-Driven Plant.
automatically by the gasholder, and the consumption of current is not large. The carburettor is surrounded by water which serves to keep it of a fairly even temperature under varying loads, and the air is dried before it enters the carburettor. Petrol is supplied according to the speed of
54
PETROL AIR-GAS.
the machine, so that the gas is of a uniform nature. The carburettor presents a large surface over which the petrol
FIG. 17. — Safety Light Co.'s Water-Driven Plant.
drops, so that with the small quantity of vapour used the whole is vaporised before it can reach the bottom.
OF THE
UNIVERS'-""
"NATIONAL* AIR-GAS APPARATUS. 55
The National air-gas apparatus consists of a hot-air engine, an air-blower, a vertical cylinder containing the petrol, and a carburettor connected by a series of pipes and valves to a small gasholder. The engine is worked by a burner (20) consuming gas produced by the apparatus, and this drives the blower /. After leaving the blower the air is divided into two streams, the right-hand supply passing to the valve m ; the supply on the left flows direct to the car- burettor, in its passage through which it is caused to impinge on the surface of the petrol, and becomes impregnated with proportionately more or less vapour, according to the amount of gas being used — thus, if only a small quantity is being consumed, only a small volume of air is passing slowly over the surface of oil in the carburettor, and becomes impregnated with a large amount of vapour, and therefore requires diluting in the mixing-box n to a very considerable extent by air from the valve m, in order to bring the proportion of hydro- carbon vapour down to i \ per cent, of the whole. When a large number of burners are turned on, a large volume of air, with a greater speed of flow, is passed over the same surface, and, as the time during which it is in contact with the petrol is far less than when only a small quantity was being used, it necessarily contains less hydrocarbon vapour, so that a proportionate part of the volume of air passing into the mixing-box requires to be cut off in order to keep the mixture uniform. This is done in the following manner: — The air- valve m and the gas-valve <?, which work in contrary direc- tions, are connected to the gasholder, which is controlled by the main valve q • thus, if more burners are turned on, the holder falls, and proportionately closes the air-valve m and opens the gas-valve o. When the burners are turned off the reverse action takes place, and thus a uniform gas is obtained under varying demands. In order to replace the heat lost in vaporising the petrol, the heated water from the
PETROL AIR. GAS.
NATIONAL" AIR-GAS APPARATUS.
57
58 ' PETROL AIR-GAS.
cooling jacket of the engine is circulated through a chamber underneath the carburettor. The temperature of the water is controlled by automatically cutting down the supply of gas to the engine burner, this being the source of heat, according to the number of burners in use. A constant level is maintained in the carburettor by means of the float feed d. This apparatus is provided with a thermostatic control. It is constructed of steel, and has a diaphragm head, and is filled with mercury. This control works the air-valve. Attached to the bell of the gasholder by a rod and lever is an air by-pass valve. When the consumption of gas is varied, this valve is caused to open and close con- currently with the air and gas valves m and o • thus, when a large quantity of gas is being used, and a large volume of air is passing through the carburettor, this valve is closed proportionately, but as the consumption decreases, this valve opens, and allows a volume of air, equal to the decrease in the gas consumption, to escape from the air main j.
The " Aerogen " gas-plant machine makes a gas of a richer nature than most others. The motive power is by means of weights for installations up to 100 lights, and hot-air engines, water, or electric motors for larger plants. The power required to work the machine is small, as it only has to drive the pressure-raising drum, and a small petrol lifter which delivers the oil in proportionate quantities to the air, drop by drop, into the carburettor. A gasholder is provided to keep the pressure even and control the working of the machine. This plant has been working for many years, principally in Germany.
The Globe safety gas plant consists of a hot-air engine, which is driven by the gas made by the plant, and which drives the compressor. The carburettor is automatically supplied with petrol from the container, which can be filled
LOCO" VAPOUR-GAS MACHINE.
59
up or only partly filled as desired. The compressor supplies the air to the carburettor for vaporising the spirit, in propor- tion to the demand for gas, and the gas thus manufactured passes into the gasholder, and from thence is distributed to the burners. The production is automatic, only the quantity of gas required at any given period is made, and this con- tains 1.52 per cent, of hydrocarbon vapour to 98.48 per cent, of air.
The " Loco " vapour-gas machine is the invention of Mr F. C. Lynde, Assoc. M.Inst.C.E. It is also one of the hot-air engine type, which drives a fan or blower to compress the air. The petrol tank is fixed outside the building, and has a glass gauge above the petrol level, which prevents the escape of petrol should the glass break. It has no moving parts except the engine and compressor, and the burner in the former can be drawn out for lighting, and the apparatus only takes three minutes to start. The
petrol feed does not require any adjustment, and the gas is kept uniform in quality under severe conditions of test. The whole of the petrol is vaporised and no residue left.
The "Solux" generator has a compressor, which may be either water or weight driven, or supplied from a storage holder. The air is conveyed, by a pipe, from the compressor to the generator, which can be placed anywhere convenient to the mansion or house it is lighting, so that there is less chance of loss through long mains, as any leakage would
FIG. 20. — "Loco" Machine.
6o
PETROL AIR-GAS.
only be of air, and this air can, if desired, be delivered at a high pressure. The air passes first through a meter, the spindle of which is connected to the petrol regulator, which measures the equivalent supply of petrol. Before the air meets the petrol, it is passed through a drying chamber to
FIG. 21. — "Solux" Apparatus.
remove all the moisture, then through a regulating governor to the carburettor, in which the petrol flows on to the surface of a sphere or ball, and the air is made to swirl around the ball, and by means of vanes the gas is churned up ensuring a uniform density of mixture. The carburettor is surrounded by a radiator containing an anti-freezing liquid, which gives
CENTENARY GAS CO.'S PLANT.
61
FIG. 22.— The Centenary Gas Co.'s Plant.
OF THE
UNIVERSITY
62 PETROL AIR-GAS.
up its heat to the carburettor to counteract the great cold caused by the evaporation of the petrol.
The Centenary Gas Company's plant consists of petrol reservoir, means for raising the petrol from this reservoir to a fountain, and from this fountain, in any fixed amount, to a chamber in which a drum with a number of compartments rotates in a sealing fluid, of water or water and glycerine. The petrol is admitted with air into several compartments of the drum in definite proportions, and the carburetted air is thence delivered by the rotation of the drum, and in this way the drum forms a carburettor, a compressor, and a meter. The petrol reservoir is placed behind the drum, the shaft of which projects into the reservoir, and has fixed upon it a disc, with a number of cups, which serve to lift the petrol up and to drop it into a small tank, with a coned valve outlet into the drum chamber. This valve is at the end of a spindle, which has a screwed portion, and extends through a stuffing box and terminates in a petrol regulator on the top of the generator, with a dial as indicator, and can be set to allow any fixed quantity of petrol to pass into the drum chamber, where it meets the air and is vaporised, being lighter than the water it floats on top of it until vaporised. The whole plant is contained in one vessel and is very com- pact. The driving power may be either weights, with rope and pulleys, or by belts or spur wheels from existing shafts, or a water wheel or turbine, electric motor, gas or steam engine, may be used. A belt-shifter, worked from a small balance-holder, with a fast and loose pulley, or an electric switch or rheostat can be used to start or stop the electric motor. The air is dried and cleaned before it enters the mixing chamber.
CHAPTER VII.
EXTRACT FROM AN ACT FOR THE SAFE KEEPING OF PETRO- LEUM AND OTHER SUBSTANCES OF A LIKE NATURE.
[2ist August 1871.]
3. For the purposes of this Act the term " petroleum " Definition of includes any rock oil, Rangoon oil, Burmah oil, oil made "Petrole.um from petroleum, coal, schist, shale, peat, or other bituminous tion of Act. substance, and any products of petroleum, or any of the above-mentioned oils ; and the term " petroleum to which this Act applies," means such of the petroleum so defined as, when tested in manner set forth in Schedule One to this Act, gives off an inflammable vapour at a temperature of less than one hundred degrees of Fahrenheit's thermometer.
6. Where any petroleum to which this Act applies — Label on
(a.) Is kept at any place except during the seven days vessels con- next after it has been imported ; or petroleum.
(b.) If sent or conveyed by land or water between any two places in the United Kingdom ; or
(c.) Is sold or exposed for sale ;
the vessel containing such petroleum shall have attached thereto a label in conspicuous characters, stating the descrip- tion of the petroleum, with the addition of the words " highly inflammable," and with the addition —
(a.) In the case of a vessel kept, of the name and address of the consignee or owner :
(£.) In the case of a vessel sent or conveyed, of the name and address of the sender :
64
PETROL AIR-GAS.
Regulations as to storage of petroleum.
Mode of granting licenses.
(<r.) In the case of a vessel sold or exposed for sale, of the name and address of the vendor.
All petroleum to which this Act applies which is kept, sent, conveyed, sold, or exposed for sale, in contravention of this section, shall, together with the vessel containing the same, be forfeited, and in addition thereto the person keeping, sending, selling, or exposing for sale the same shall for each offence be liable to a penalty not exceeding five pounds.
7. Save as hereinafter mentioned, after the passing of this Act petroleum to which this Act applies shall not be kept, except in pursuance of a license given by such local authority as is in this Act mentioned.
All petroleum kept in contravention of this section shall, together with the vessel containing the same, be forfeited, and in addition thereto the occupier of the place in which such petroleum is so kept shall be liable to a penalty not exceeding twenty pounds a day for each day during which such petroleum is so kept.
This section shall not apply to any petroleum kept either for private use or for sale, provided the following conditions are complied with :
(i.) That it is kept in separate glass, earthenware, or metal vessels, each of which contains not more than a pint, and is securely stopped :
(2.) That the aggregate amount kept, supposing the whole contents of the vessels to be in bulk, does not exceed three gallons.
9. Licenses in pursuance of this Act shall be valid if signed by two or more of the persons constituting the local authority, or executed in any other way in which other licenses, if any, granted by such authority are executed. Licenses may be granted for a limited time and may be subject to renewal or not in such manner as the local authority think necessary.
PETROLEUM ACT, 1871. 65
There may be annexed to any such license such con- ditions as to the mode of storage, the nature and situation of the premises in which, and the nature of the goods with which petroleum to which this Act applies is to be stored, the facilities for the testing of such petroleum from time to time, the mode of carrying such petroleum within the district of the licensing authority, and generally as to the safe keeping of such petroleum as may seem expedient to the local authority.
Any licensee violating any of the conditions of his license shall be deemed to be an unlicensed person. There may be charged in respect of each license granted in pursuance of this Act such sum, not exceeding five shillings, as the local authority may think fit to charge.
IT. Any officer authorised by the local authority may Testing of purchase any petroleum from any dealer in it, or may, on P^™!611"1 by producing a copy of his appointment, purporting to be local authority certified by the clerk or some member of the local authority, or producing some other sufficient authority, require the dealer to show him every or any place, and all or any of the vessels in which any petroleum in his possession is kept, and to give him samples of such petroleum on payment of the value of such samples.
When the officer has by either of the means aforesaid taken samples of petroleum, he may declare in writing to the dealer that he is about to test the same, or cause the same to be tested, in manner set forth in Schedule One to this Act, and it shall be lawful for him to test the same or cause the same to be tested, at any convenient place at such reasonable time as he may appoint, and the dealer or any person appointed by him may be present at the testing, and if it appear to the officer or other person so testing that the petroleum from which such samples have been taken is petroleum to which this Act applies, such officer or other
E
. 66 PETROL AIR-GAS.
person may certify such fact, and the certificate so given shall be receivable as evidence in any proceedings that may be taken against a dealer in petroleum in pursuance of this Act ; but it shall be lawful for a dealer proceeded against to give evidence in proof that such certificate is incorrect, and thereupon the court before which any such proceedings may be taken may, if such court think fit, appoint some person skilled in testing petroleum to examine the samples to which such certificates relate, and to declare whether such certi- ficate is correct or incorrect.
Any expenses incurred in testing any petroleum of such dealer in pursuance of this section shall, if such dealer be convicted of keeping, sending, conveying, selling, or expos- ing for sale, petroleum in contravention of this Act, be deemed to be a portion of the costs of the proceedings against him, and shall be paid by him accordingly. In any other event such expenses shall be paid by the local autho- rity out of any funds for the time being in their hands, and in case the local authority are the justices, out of the county rate.
Penalty for I2- Any dealer who refuses to show to any officer autho-
refusing infor- rised by the local authority every or any place or all or any obstructing °* ^e vessels ^n which petroleum in his possession is kept, officer. or to give him such assistance as he may require for examin-
ing the same, or to give to such officer samples of such petroleum on payment of the value of such samples, or who wilfully obstructs the local authority, or any officer of the local authority, in the execution of this Act, shall incur a penalty not exceeding twenty pounds. Search for 13. Where any court of summary jurisdiction is satisfied by
petroleum. information on oath that there is reasonable ground to believe See 23 & 24 , . ......
Viet., c. 139, that any petroleum to which this Act applies is being kept,
s- 25- sent, conveyed, or exposed for sale within the jurisdiction of
such court in contravention of this Act, at any place, whether
PEl^KOLEUM ACT, 1871. 67
a building or not, or in any ship or vehicle, such court shall grant a warrant by virtue whereof it shall be lawful for any person named in such warrant to enter the place, ship, or vehicle named in such warrant, and every part thereof, and examine the same and search for petroleum therein, and take samples of any petroleum found therein, and if any petro- leum to which this Act applies be found therein, which is kept, sent, conveyed, or exposed for sale, in contravention of this Act, to seize and remove such petroleum, and the vessel containing the same, and to detain such petroleum and vessel until some court of summary jurisdiction has determined whether the same are or not forfeited, the pro- ceedings for which forfeiture shall be commenced forthwith after the seizure.
Any person seizing any petroleum to which this Act applies in pursuance of this section shall not be liable to any suit for detaining the same, or for any loss or damage incurred in respect of such petroleum, otherwise than by any wilful act or neglect while the same is so detained.
If any petroleum to which this Act applies is seized in pursuance of this section in any ship or vehicle, the person seizing the same may use for the purposes of the removal thereof, during twenty-four hours after the seizure, the said ship or vehicle, with the tackle, beasts, and accoutrements belonging thereto, and if he do so shall pay to the owner thereof a reasonable recompense for the use thereof, and the amount of such recompense shall, in case of dispute, be settled by the court of summary jurisdiction before whom proceedings for the forfeiture are taken, and may be re- covered in like manner as penalties under this Act may be recovered.
Any person who, by himself or by any one in his employ or acting by his direction or with his consent, refuses or fails to admit into any place occupied by or under the
68 PETROL AIR-GAS.
control of such person, any person demanding to enter in pursuance of this section, or in any way obstructs or prevents any person in or from making any such search, examina- tion, or seizure, or taking any such samples as authorised by this section, shall be liable to pay a penalty not exceed- ing twenty pounds, and to forfeit all petroleum to which this Act applies which is found in his possession or under his control.
MEMORANDA.
I inch = 25.40 millimetres.
I gallon = .1604 cubic foot=lO Ibs. water at 62° F.
i cubic foot of water weighs 62.4 Ibs.
I horse-power = 33,000 foot pounds per minute.
A column of water 27.6 inches high corresponds to a pressure of i Ib. per square inch.
The weight per gallon of a liquid may be obtained by multiplying the specific gravity by 10.
To test specific gravity of petrol use a hydrometer. (This can be obtained at most motor stores. )
i cubic foot of hydrogen at o° C. and i atmosphere weighs .00559 Ib. i cubic foot of air at o° C. and i atmosphere weighs .0807 Ib. 1,000 cubic feet = 28. 315 cubic metres, i cubic metre — 35.3156 cubic feet.
i atmosphere =14. 7 Ibs. per square inch = 2116. 8 Ibs. per square foot = 760 millimetres of mercury.
The composition of the atmosphere is as follows : — Oxygen by volume, 20.8 ; by weight, 23. Nitrogen by volume, 79.2 ; by weight, 77. It also contains a little
ammoniacal gas, and from 3 to 6 parts in 10,000 of its volume
of CO.^.
Gas expands ^f=r of its own volume for every i° C. 1 Charles's Law
» 1^2" » >» » ^ *• J
A British thermal unit (B.Th.U.) is the amount of heat required to raise I Ib. of water from 39.1 to 40.1° F.
70 MEMORANDA.
Standard candles are made of spermaceti, and about 4 to 5 per cent, of beeswax, measure 8f inches long, and are made 6 to the Ib. They must consume the spermaceti within 5 per cent, of the proper rate of 1 20 grains per hour.
A candle-hour is the amount of light given by I candle burning for a period of I hour.
A candle-foot is the light of a candle measured at I foot distance. Light diminishes as the square of the distance.
The specific gravity of a body is its weight as compared with that of an equal bulk of some other body. Solids and liquids are compared with water ; gas with air.
Iron pipes are measured inside ; brass and copper pipes outside.
INDEX.
ACETYLENE gas, 4 Acetylene gas explosions, 6 Advantages of petrol air-gas, 8 " Aerogen" machine, 58 "Alpha" machine, 38
BALANCE holder, 36 Blower, "Root's, "33 Bunsen burners, 24 Burner, " Carmian," 45 Burners, theory of, 24
SAKE of petrol, 22 ' ' Carmian " portable gas, 44 ntenary " plant, 61 Coal-gas plants, 2 Cost of acetylene gas, 5
— of coal-gas plant, 3 — of oil-gas plant, 4
— of petrol air-gas plant, 12
DEFINITION of petrol, 63 De Laitte patents, 52 Description of plants, 38 Disposing of waste petrol, 18
ELECTRIC light, 6 Elwell-Smith patents, 52 Engines, hot-air, 34 " Eos " apparatus, 50 Explosions with acetylene gas, 6 Explosive mixtures, 16 Extinguishing lighted petrol, 17
FIRE extinguisher, 19 Fitting up mantles, 28 Flame intensity, 28 Friction of pulleys, 33
21
GAS made per gallon getrol Gasoline, 14 Gasoline vapours retained by air, 14 Gillie's apparatus, 44 "Globe" safety plant, 58 Granting licenses, 64
HEARSON'S " Sun " machine, 39
Heat absorbed in vapourising, 17 Heat of flame, 25 Height required for weights, 32 History of petrol gas, 10 Holder pumps, 37 Hot-air engines, 34
INCANDESCENT mantle male- 1 ing, 29 Intensity of flame, 28 Inverted burners, 26 "Invetrol" light, 46
OINTS in petrol pipes, 30
LABELS on petrol vessels, 63 Lamps, oil, objections to, I Leaks in petrol pipes, 30
INDEX.
License granting, 64 — necessary, 22 " Loco" vapour-gas machine, 59
MAKING incandescent mantles, 29
Mantles, clean and dirty, 28 — fitting up, 28 Motive power meters, 31 Muller's " Alpha" machine, 38
air-gas appara-
"XTATIONAL'
IN tus, 55 Non-explosive Gas Co.'s plant, 47 Notes, useful, 69 Notkin lamp, 41
OBJECTIONS to acetylene gas, 8
— to coal-gas plants, 7
- to electricity, 8
— to oil-gas plants, 7
— to oil lamps, I Oil-gas plant, 3 Oxygen required, 22
P ELTON wheels, 35 Penalty for obstructing officer,
66
Pentane, 14 Petrol, 13
— care of, 22
- extinguishing lighted, 17
— filler, 19
— fire extinguisher, 19
— gas made per gallon, 21
— safety gas, 1 1
— store house, 23
Petrol storing, 64
— tanks, 35
— testing, 65
- thermal values of, 1 7
— waste, disposing of, 18 "Petrolite" lamp, 42 Petroleum Act, 1871, 63 Petroleum liquid absorbed by air, 15 Pipes for petrol, 30
— required, 27
Pitner " Invetrol" plant, 47 " Praed" safety lamp, 48 Pressure required, 27 Pulleys, friction of, 33
R
OOT'S blower, 33
SAFETY Light Co.'s plant, 52 Search for petroleum, 66 " Solux" generator, 59 Spirit safe, 20 Storehouse for petrol, 23 Storing petrol, 64 " Sun" machine, 39
TANKS for petrol, 35 Testing petrol, 65 Theory of burners, 24 Thermal values of petrol, 17
u
SEFUL notes, 69
WATER motors, 35 Watson's machine, 40 Weights, height required for, 3: Wet meters, 31
Printed at THE DAKIEN PRESS, Edinburgh.
ADVERTISEMENTS.
IV
GALSWORTHY
LIMITED.
Wholesale Manufacturers and Specialists in
GAS FITTINGS
For all Systems.
Showrooms and Offices:
15 & 16 NEWMAN STREET
OXFORD STREET, W.
Telephone: GERRARD, 5621. Factories :
ROBERTS WORKS, HAMPSTEAD RD., H.W.
Telephone: NORTH, 441.
ADVERTISEMENTS.
The "CENTENARY"
PETROL GAS
Turbine Generator
FOR 300 LIGHTS.
For Supply to a City or a Cottage.
Prices and full particulars from
The Centenary Gas Co.,
(DEPT. C.)
tt QUEEN VICTORIA ST., LONDON, E.C And 109 HOPE STREET, GLASGOW, j* <*
ADVERTISEMENTS. VI
"SOLUX"
AUTOMATIC SAFETY AIR-GAS
GENERATOR.
A simple yet perfectly automatic plant for generating Petrol Air Gas for country house and village lighting. The cheapest, cleanest, and safest gas known. Correspondence invited.
WM. SHEARER, A.M.l.Mech.E., A.M.I.E.E.,
'Phone, 1058. Patentee and Manufacturer,
Telegrams, "SOLUX."
ABC code, 5th Edition. 53 & 59 Thistle Street, EDINBURGH.
"CARMIEN" PORTABLE GAS
Cheapest, Safest, Best, and Simplest Illuminant for Country Use, also for Heating and Cooking.
The Light, which costs one penny per six hours for a 7o-candle power burner, is produced by a blue flame acting on an incandescent mantle.
The Gas for the Light is generated in the burner itself (there being no machinery) from Petrol supplied to it by a very fine 2 m/m copper tube leading from Petrol tank fixed on roof, wall, or window-sill.
There are no unsightly gas pipes, therefore no damage to walls, &c. The tubes can be bent like wire, and are practically invisible. No fumes to blacken ceiling.
The whole installation is of the utmost simplicity, and can be fitted by any tyro.
Write for Booklet "B" of Testimonials, Diagrams, and Catalogue. Agents wanted where not already represented. .'. Apply
HENRY DUTTOH & CO., 7 Fisher St., Southampton Row, LONDON
(Late of Leicester),
Vll
The
COUN=
SHOP:
A compl
THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW
AN INITIAL FINE OF 25 CFNTQ
FEB 27 1933
TheJ
8S1
i
Write for Catalogue.
LD 21-50m-l,'8J
ADVERTISEMENTS. Vlll
THE FINEST SPIRIT FOR PETROL GAS _- SYSTEMS
IS THE
ANGLO
SPECIAL
FOR GAS
AND
695.
aniform in quality, and points which renders it easy to vaporise.
Packed in green cans with label printed in red with the above wording. Obtainable of all Motor Spirit
Dealers.
ANGLO-AMERICAN OIL CO. LTD.
22 Billitcr Street, LONDON, E.C.