A, C, rlOVnN K. W. VAN VALZAM
,OGY
AlvAOUR ll-^STrrUir
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http://www.archive.org/details/proposeddesignfoOOhove
A PROPOSED DESIGN FOR THE REFRIGERA-
TION LABORATORY FOR THE GREATER
ARMOUR INSTITUTE OF TECHNOLOGY
12.
A THESIS
PRESENTED BY
ALFRED C. HOVEN AND ROBERT W. VAN VALZAH
TO THE
PRESIDENT AND FACULTY
OF
ARMOUR INSTITUTE OF TECHNOLOGY
FOB THE DEGREE OF
BACHELOR OF SCIENCE
IN MECHANICAL ENGINEERING
JUNE 2, 1921
APPROVED
ILLINOIS INSTITUTE OF TECHNOLOGY . ^.^--^CT^/^/ ,^/.-.^,l
PAUL V. GALViN LIBRARY '^"'""^ °' ^'"""'"^ Engineering
36 WEST 33RD STREET
CHICAGO, IL 60616 °"" °' Enemeenn. Studies
Dean of Cultural Studies
JTixe
TAE-LE OF CONTENTS
I . INTRODUCTION
II. BUILDING
A. Mater-lal and Construction
B . Layout
III. EXPSRII'IENTAL ROOMS A. Insulation B' Piping
C . Machines
IV. ICE IMICING
A. Freezing Tank
B. Water Supply C Machines
V. SMALL I.'IACHINES
A. Creamery Package Refrigerating Machine • B. Lipman Refrigerating Machine
C. Continental Refrigerating Machine
D. Frigldaire Refrigerator
.^981
o
PLATES
PAai
Autoraat-ic Carbonic Compressor 19
York Absorption Machine 26
York Compression Machine 52
York Piping Layout - W;i,ter and Brine 36
Raw TiVater Systeui 3S
Creamery Package Compressor 43
Creamery Package Refrigerating Machine 45
Continental Refrigerating System 48
Li'pman Refrigerating Machine 52
Frigidalre Refrigerator 57
Laboratory Floor Plan 59
I. introdiictiot:
Although refrlger: tion E.nd the production of ice by artificial means was known to the a,nc- ientsjit is only v/ithin comparatively recent times that improved systeris and appare^tus have enabled operations to be carried out on a cominer- cial basis- Fifty years ago the refrigeration in- dustry was in its infancy but great strides have been made since then. Last year, in America alone, there v/ei-e over seven thousand firms directly in- terested in the mechanical production of cold.
Few people realize the full significance of the part this industry plays in our daily life. Refrigerant ion machines are used for making ice, for chilling fresh kij.led meat, for preserving perishable foods, for conditioning of air, for mak- ing celluloid films, and for many other industri- al "processes. They make it possible for the "Salty Tar" to eat fresh foods when cruising off the South Sea Isles while his sv/eetheart sits com- fortably in an air cooled movie house in Brookl\Ti.
4
Because the future of the Inductry depends so largely on tho engineer, we are anxious that the New and Greater Armour Ii'.stitute of Technol- ogy shall have a refrigeration laboratory v/hlch la,cks not a single detail essential to complete experimentation. Therefore in the design of the new laboratory our first concern has been for completeness, '.'.'e have aimed to make the labora- tory of the greatest possible practical value. The units chosen, each in its class, represent the best in modern prs.ctice. Together they cover very thoroughly the present day methods for the production of cold.
The wor;: done by refrigeration machines may be divided into two general classes, as follows:
1. The Manufacture of Ice.
2. Cooliv.g by Direct Absorption of Heat. To re-oresent the first class of work, the
new laboratory will be equipped with a tank for the manufacture of ice by the can system, either on direct or indirect expansion, using either raw or distilled v/ater. The free:ring may be done by (O an aramonia compressor, (2) a carbon dioxide
5 compressor, or (3) cin ammonia absorption machine.
The second class of work Is represented in the three insulated rooms located at one end of the laboratory. Each of these rooms may be cooled 'Off by any of the above mentioned machines. One of the rooms will be equipped with ste;:,m coils and Y/111 be used in connection with experiments on heating and ventilating.
The equipment of the new laborf-.tory \illl also Include three small machines of the type used in butcher boxes, floral shops, and apart- ment buildings. The demand for machines of this type is growing rapidly s.nd the conpetitlon is keen. The merchant is awakening to the fact ths.t the ice man's muss and Irregularity are unneces- s8.ry evils.
One machine of the household size is provid- ed to afford data on the economy and reliability of machines designed for this purpose. The field is greater than Henry Ford's, but it has just been entered.
BIBLIOG-RAPKY
The Llechanlcal Production of Cold
Ewing The Carbonic Acid Industry
G-oosman Elements of Refrigeration
G-reene Evaporating, Condensing, and Cooling Apparatus
Hausbra.ad Modern Refrlgers.tion Llachines
Lorenze and Pope MechanlcaJ. Refrigeration
Mac In tyre Refrigeration, Cold Storage, and Ice Making
Tayler Complete Catalogue of Ammonia Valves and Fittings
York Manufa.cturing Company
II. ^UILDIIIG
MATERIAL AND CONSTRUCTION
The Refrigeration Labo re-tor;: for the Nevf and G-reater Armour Institute of TechnolOG2-^ v;ill be located in a one story brick building, sixty feet v.-ide and one hundred thirty feet long. The build- ing will be fireproof throughout. The inside of the W8.11s shall be of hollov/ tile except in th-j offices, wash rooms, and experimental rooms. The walls of offices and v/ash rooms will be finished in hard plaster. The insulation, v/hich forms the walls of the experimental rooms, is described in the part of the thesis devoted to the rooms.
The floor will be made of eight inch concrete, surfaced v;ith dust proof covering. The floor in the offices will be of a selected maple.
The roof will be of the garage type, support- ed by posts set twenty feet apart. On the roof, a platform will be constucted directly above the refrigerating machine to be used in cooling the altitude chamber. This platform is to support the atmospheric condenser to be used in connection
vfith that machine.
LAYOUT
In layin,3 out the refrigera,tion laboratory the ohject sought was compactness v.-lthout crowd- ing or inaccessibility. The future of the labor- atory,with Its probable expansion and moderniz- ing was kept constantly in view.
The entrance to the office and the labora- tory will be at an end of the building. The off- ice will be adjoining and connected to the vrash- room and lavatory. The work bench will be located jUEt outside of the wash-room. The Frigidaire re- frigerator and two cases for exhibits will be placed against the office wall.
The other end of the labora,tory v/ill be de- voted to the experimental rooms. There will be three rooms each thirty by tv/enty feet. They may may be cooled by any of the three machines to be located near the rooms. The Automatic Carbonic machine will be in front of the rooms and the York compression and absorption machines will be
9 placed near either v/:-,ll . The ice tanlc will occu.tj the "U" fornied by these three machines.
The altitude chanber will be across the lab- oratory from the office. It, and its equipment v/111 form a seperate unit. The small machines villi be placed along the wall between the altitude chamber and the Yorlc absorption mc-chine.
10
III. EXPERlIvIENTAL ROOMS
The tonnage of refrigeration devoted to cooling by direct absorption of heat has come to exceed that devoted to the manuf^.cture of ice. We are gradually aproe,ching an iceless age. In order th t the problems confronting the engin- eer T7ho designs coll storage houses and cooling rooms may be thoroughly studied, the nev/ labora- tory will contain three experimental rooms.
Each room will be thirty feet long by twenty feet T;ide. The two cold rooms will be ten feet high, but the constant temperature room will be twenty feet high to permit experimenting with structures of more than one story. Each room vrill open into the laboratory, and the room.s will also be interconnected. The wall between the constant temperature room end the adjoining cold room will contain a false section '.-hlch can be removed. This section will afford an opportunity to study heat conductivity of large sections placed be- tvfeen any desired difference of temperature.
An altitude chamber ha,s been provided for
11
the automotive department to be used in testing aeroplane motors under conditions found in high altitudes. All the necessa.ry Instruments and ap- paratus Virill be furnished by the automotive dep- artment. The room will be 8' x 10' x S ' . It v/ill be cooled indirectly by a two-stage carbon diox- ide compressor designed and built by the American Carbonic Company. This machine is especially a- dapted to the work which will be asked of it; similar machines are used throughout the country for just such work.
Experiments run in this room v/ill require the removal of about 150 tons of refrigera.ti jn per day..- ■ A ten ton machine is provided to be used in connection v/ith a brine tank which forms the inner walls of the room, and has a capacity of 650 cu . ft. of brine. By running the refrig- erating machine until all the brine is frozen, a cape.clty of about I80 tons may be stored up.
A ten ton York atmospheric condenser' will be provided for use in connection v/ith the al- titude cham.ber and in experiments on the effic- iency of this type of condenser.
12
INSULATION ■ All v;alln,partitlonG, floors, and ceilings shall be made of Wonpareil corkboard, manufact- ured by the Arnstrong Cork and Insulation Company, and shall comply to the follov.'lng spec- ifications :
TfALLS Directly against the brick walls, one course of three inch Nonpareil corkboard shall be erect- ed in a 1/2 inch bed of Portland cement mortar, mixed in the proportion of one part of Portland cement to tv/o parts of clean, sharp sand, all vert- ical joints being broken. A second course of three inch Nonpareil corkboard shall then be erected against the first in a 1/2 inch bed of Portland cement, a.nd additionally secured to the first v:lth galvanized wire nails or V700den skewers. All joints in the second course she.ll be broken v/ith respect to all joints -in the first course. All joints shall be made tight.
13
CEILING- The insulation against the ceiling chc.ll be the same as that specified above for the v;. lis.
FLOORS On a reasonably smooth and level concrete ba,se, one course of tjii'ee inch ITonpareil cork- board shall be laid dovrn In hot aspha,lt,all trancverse joints being broken. 2 inch x 3 inch sleepers sha,ll be laid dovrn on 38 inch centers. Between the sleepers, a second courseof 3 inch corkboard shall be laid on hot osphalt. All joints in the second course shall be broken \rlth respect to all joints in the first course. All joints shall be made tight. The upper surface shall be flooded v/oth hot asphalt, approximately l/S inch thick. T.& G-. flooring shall then be securely nailed dovm to the sleepers. Selected maple shall be used for the flooring.
?ARTITI01TS The insulation on partitions shall be ei-ect- ed according to the specifics.tions laid dovni foz"
14
the v/alls except, that two courser, of tv.-o-inch ITonparell corhboard shell be placed on each side of the partition proper.
PIPING
The ammonia coils in the direct expansion rooms and the brine colls in the indirect expan- sion rooms shall be placed on each thirty foot v^all, close up to ceilin/j;. Each coil shall be tv/o pipes v/ide and ten pipes high, with four inches between pipe centers. All pipes used shall be Byers ' 2-inch Virrought iron pipe.
The piping specified above is sufficient to remove 3'^,'^-^^'^ B.T.U. per hour with a ten degree difference in temperature betv/een the room and the brine or ammonia. 2.5 v/as used as the coef- ficient of hect transmission.
15
MCHIiJES
The machines which viere chosen to cool the experimenta,! rooms, and vfhich are also used for ice making, represent the entire field of large scale coumiercial refrigeration. The compression system is represented in the Automatic and York machines; the absorption system is represented in the York absorption machine. By means of these machines a comp;;,rison of ammonia and carbon diox- ide refrigeration may be obtained. The York v/ill be steam driven; an electric motor v;ill drive the carbon dioxide machine.
16
AUTOI/IATIC CARBONIC RSPRICr-^R/iTING SYCTEM
The use of carbon dioxide as a refrigerating agent is increasing ver^f rc^pidl;/,and the condi- tions under which it is adrnitedly superior arg becoming more numerous,. Carbon dioxide is more powerful! than any of the other practical refrig- erants. The saving in space vrtiich results from this fact is often of such great importance that it becomes the deciding factoi-.
Safety under any 3,nd all conditions is per- haps the most valuable characteristic of this gas; it Is non-Gxplosive,non-inflamable,and non- asphyxiating. It is this property v/hich has led to its almost universal adoption for use in hos- pitals,hotels, and asylurds .
■ Because of its very low boiling point, car- bon dioxide has come into great favor for low temperature work. In aerona.utical experimenta.l work and in the manufacture of films temperatures of forty to seventy degrees belovf zero are obtain- ed.
Taking these valuable features as a basis the
17
Automa.tic Carbonic Ilachine Company has designed and manufactured a machined v;hich hcs every favor- able point built into it and which applies the natural advanta.ges of this go-s in a thoi^oughly practical and simple way. A copy of the specifi- cations for a three ton system d.s taken from the contract is" given below.
18
COLIPRESSOR
The compressor shall be of the automatic carbonic safety type, arranged with safety pockets for the suction and discharge valves, automatical- ly controlled stuffing box, pressure controlling device, and safety valve.
The compressor sha.ll be lubricated in the folloTang manner: A tvfo compartment force feed lubricating pump of the Kills-Mc Canraa type shall be provided. One compartment of the pump shall be connected v/ith the stuffing box of the com- pressor for the lubrication of the same. The otlier compartment of the pump shall be used for the lubrication of all bearings and moving parts by meansof a speciaJ oil distributor with a vis- ible oil supply going to the distributor from the lubricating pump. Independently- oiled valve leads shall be connected from the distributor to each bearing and moving pa.rt.
The compressor suction and disch-arge valves shall be of the nevf plate type.
19
20
CONDENSER
The condenser shall be of tlie shell type, v/lth copper cooling coils, for the circulation of the water, so arranged that the carbonic gas after liquifaction will be cooled to the lowest temper- ature of the incoming water, arranged in counter current cycle.
Each condenser shell shall be designed to meet the requirements of the rules issued by tlB Safety Inspectors of the Cities of Chicago and New York
BRIDIE COOLER The brine cooler sha.ll be of the shell type of constuction with ample copper cooling surface to reduce the temperature of the circulating brine to within ten (10) degrees of the tempera- ture of the evaporating carbonic gas when the temperature of evaporation is zero degreesFahr.
21
AUTOriATIG EXPAITSIOIT VALVE The valve conurolllns the evaporation of the carbonic gc.s throush the brine coolers shall be of the automatic pressure relation type requir- ing no hand adjustment. This valve shall ';e pro- vided v/ith two diaphragms operated by the liquid a.nd evaporating pressures in such a v;ay that the valve orifice is controlled in its opening by the action of the tv/o pressures on the two diaphragms.
WATER FLOY; CONTROL VALVE The overflov/ v;joter from the condenser shall be provided with a thermostatically controlled valve in such a way that the quantity of water is controlled and regulated in accordance with the heat quantity going into the condenser-. That is, the control v.-.lve shall allow, automatic- ally, a greater amount of water to pass through the condenser cooling coils whenever the heat
22 flow into the condenser incre:^ses,and a less quantity of water with a decrease of heat flov; into the condenser. This flow of water shall be cut off automatically when the compressor is shut do v7n, and shall start automatically when the compressor is started.
OIL SEPERATOR There shall be co:anected in the high press- ure line,betY/een the compressor and the condens- er, an efficient oil separator so arranged that the entering gas is deflected in the direction of its flov/, reduced in velocity so that the en- trained oil may easily be deposited on a suitable perforated fumiel,the gas thereafter passing in- to the u^per pa.rt of the seperator. Suitable neans to draw off the oil,v;ithout ca-using splashing ■. . shall be Provided.
i^5 SCALE TRAP A scale trap similar in design to the oil sepax'ator shall be connected at a suits.ble lo- cation in the suction pipe leading from the e- vaporators to the compressor.
24 YOmi ABSORPTION REFRIGERATING SYSTEM
Absorption machiiieG viere first built to meet the increased demand for lov/ temperature v/ork.In many cases these machines can be installed and operated more economicaAly than any other type. This method of refrigerivtion is especially desir~ c.ble for the temperatures required by oil refin- eries, fish freezers, and cold storage plc.nts.
There are man;*" cases in which greatly in- creased economy has been obtained in existing compression plants by using the exlicust steam from the compression plant ;-uxiliaries in the ammonia generator of an absorption machine. It is often desirable to install this type of mach- , Ine in hotels, apartment housevS, hospitals, or elec-- trie poY/er plants, where exhaust steam is availa- ble. A pressure of one pound gauge is sufficient for satisfs.ctory opera-tion.
The Yorlc ".lanufac taring Company is the lead- ing m.aker of absorption machines- The system to be installed in the nevf laboratory will be designed by them to raeet the following specifications:
25 GENERATOR
The generator shall be of the shell and tube type and shall be raade of cast air furnace iron having a tensile strength of not less than 55,000 to 60,3";0 pounds per sq.uare inch.
No rivets shall be used in any part of the shell; all seams shall be welded, thus avoidin<j; leakage due' to contract lor. and expan3ion.
The shell sh-:.ll be designed for use with an external analyzer
ANALYZER . The analyzer shall be of the extenal type. It shall consist of a cast air furnace iron shell providedvrith cast iron heat exchanger trays, over which the incoming strong aqua flov/s, counter cur- rent to the outgoing gas, coming in direct conta.ct with the same.
26
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27
DSHYDR/iTOR
The dehydrc.tor shall be of the double pipe type,8.nd provided \ilth all the necessary fittings, valves, headers, sta.nds, and a drip tray. The pipin^^ shall be of selected 1 l/2" and 3" aramonia pipe. All parts shall be made of cast close grained air furno.ce iron.
The combined gas and water vapor shall enter the annular spc.ce of the coil a,t the top, and leave it at the botton, -vhere it shall enter the drip trap, which will effectually separate the condens- ed water from the ammonia g;-.,s and return it to the generator, vhile the anliydrous t.mmonia passes on to the ammonia condenser. The cooling water shall be circulated counter current to the ammon- ia, entering the inner c^il of the pipe at the bot- tom and lea.ving it a,t the top.
GOITDENSER ^^
The condenser snail be of the double pipe type, made of selected 1 l/4" and 2" ammonia pipe, and provided with all the necessary stands, head- ers, valves, and fittings.
The gas shall enter the annular spe.ce at the top, the liquid leaving at the bottom, while the cooling waiter enters the injier pipe at the bottom and passes through ':he coil counter current to the ammonia.
EXCHANGER The exchanger shall be of the double pipe type, made of selected 1 1/4" and 2" ammonia pipe. It shall be so a.rranged that the strong and v/eak liquor shall flow counter current and at high velocity so that a good hea.t transmission shall be obtained. The strong aqua ammonit. entering the generator shall have a temperature not more than
29 eight degrees below the temperature in the gen- erator.
WEAK AQUA COOLER The \7eak aqua cjolei' shall be of the double pipe t^'pe made of selected 1 1/4" .and 2" ammonia pipe. The v/eak aqua ammonia shall flovf counter current to the cooling v/ater and its temperature on leaving shall not be more than five degrees highei' than the tempera.ture of the cooling water,
ABSORBER The absorber shall be of the double pipe type of 2" and 3" selected amraonia pipe, complete with stands, valves, headers, special gas and weak
30 aqua anmonla injection fitting/, and purging drum. The cooling v/ater shall flov/ through the inner pipe counter current to the weak aqua ammonia and the amiuonla gas.
31
YORK COMPRESS lOI-I RITFRIC-ERATING IIACHIl^IE
The ainrnonia compression refrlf^erating syst- em Is at present hj far the moct prevalent meth- od of' refrigeration. The machine v/hich vill rep- resent this field is now located in the present refrigeration lahoi-jitory of the AD^mour Institute of Technology. It is complete and is in rtood op- f.ra.ting condition. It ha,s been used for experim- ental purposes since 1911 vrith very satisfactory results.
The compressor is of the single cylinder, single acting, vertical type. It is driven by a horizontal, slide valve direct coupled, ctem en- gine. It is fitted with a safety head. The main shaft is of forged and ha.mmered steel. The con- necting rods are cast steel made in an I-beam section. The piston ia fitted with metallic pack- ing and the piston rod is fitted v/ith soft pack- ing. All v/earing and bearing surfaces are fitted with automatic oilers.
The ammonia condenser and the brine cooler are of the double pipe type and are incased in granulated cork to reduce the radiation losses.
32
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Oil which is candied over from the compres- sor is removed by the oil separator located in the high pressure line.
The v; eight of aniLionia. used during any run can be determined hy mea.ns of two liquid receiv- ers which rest on platform scales.
An exchanger has been provided so that the system may be run dry,V'fet,or superheated.
This system will be removed to the new lab- ora.tory and set up there with but a ver.y fev/ changes in minor details. The only addition to the system will be the piping to the rooms.
34
ICE ■HAILING
The production of artificial ice has increased to such an extent that,althour;^h the yearly ice crop produces fluctuations in the price of ice, the public is no longer dependent upon the wint- er v^eather for its ice supply. In spite of the hlQa cost of material, labor, and fuel, there is a gradual decrease in the expense Involved in the production of a ton of ice.
Tlie ice tanlc nov; installed in the present refrigeration la,boratory y^III be moved, v/lth its appurtenances, to the new laboratory and, connected to the three three-tai refrigerating machines. This tank is six by fifteen feet and has a cap- acity of one and one half tons of ice. It contains thirty-six one hundred pound cans. The only add- ition to the freezing tank will be the air head- ers for the raw water system. The insulation v'ill be the same as how surrounds the tank.
35
WATER SUPPLY
With the development of the Internal com- bustion engine e/ad the possibility of getting electrical pov/ei' at a sufficiently low rate to justify its use in the operation of ice plants, there has come a remarkably o^uick change from the distilled water ice plant to the raw waiter ice plant.
When steam v/sx the most economical and sat- isfactiry method of driving compressors, the ex- haust steam from the driving engine vies condens- ed, filtered, and reboiled. From the reboiler the steam was run through another condenser into a holding te.nk. The ice can filler was connected to this tank.
In the new laboratory, the driving unit of the York compressor will furnish the stei.m for the distilled water method of making ice. All the apparatus necessary for the operation of such a system is installed in the old laboratory.
The rapidly increasing demand for raw water plants makes it inpera-tive that the nev; labora-
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tory contain apparatus necessary for the nicinufac- ture of ice from raw v/ater. Because of its sim- plicity and economy of operation, the York high pressure air system has been chosen to prevent the formation of y/hite or snov/ ice.
The air is drawn into the electrically driven compressor from a header extending above the roof. It is brought up to the necessary press- ure, virhich depends upon the temperature of the brine, is discharged into the receiver, and passes through the vrater cooled dehumidifier, to the brine cooled dehumidifier.
This dehumidifier is of the shell and tube type. The brine is circulated through the coils, and the air passes around them. In cooling the air the moisture is frozen off. The brine cooler is in duplicate so that the frost on one set of colls can be ths.wed off v;hile the other is doing the final work of cooling. This is done by allov/- ing the air from the water section to pass up through one chamber and dovm through the other. The brine is not circulated through the first chamber and the air, being warmer than the frost
38
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39 or Ice on the coils, melts it as it passes up through the chamber; then it cr3£Sf;s over into the other shell and comes into contact v;ith the coils through which the brine is being circulated, It is thus cooled to the temperature required to dry it sufficiently for use in the ice can. llhen the temperature of the air leaving the second chamber begins to rise, the four-way cock is throwr over,and the direction of flow is reversed. The brine is made to flow through the other coil;.. A reversal is necessary about twice a day.
An electrically driven centrifu^^al pump is provided to circulate the brine.
The apparatus to be Installed will be large enough to use in connection v/ith experiments in- volving air conditioning.
lilACHINES A complete description of the machines used for ice making is given In the secti.>n devoted to the experimental roo:ns. Any one of the three raa-chines may be used for makin,--^, ice.
40
SIiTALL REFRIGERATION I.IACHINES
The ton:ia{~e of reirlgere.tion produced "by snail refrigeration machines will perhaps never equal that of the large machines, but the number of men required to make and sell them and to supply the necessary service, will soon undoubted- ly, be far greater. The long felt need for depend- able, efficient refrisercttlon,by the merchant who does not conduct an exten.slve business, has been fulfilled in the machines now built for his needs.
Uncertainty of both prices and deliveries - poor, inefficient refrigeration, and conseajaently spoiled products - constitute a fev: of the many losses sustained through being everlastingly with- in the power of the ice man; all of them work to the menace of those dispensing perishable goods.
The thousands of merchants who today are pro- fiting and benefiting in many ways through the a- gency of nechanical refrigeratijn would not re- turn to the use of ice for refrigeration any more than they viould re- employ the ancient lethods of keeping charge accou its on a spindle, or weighing
41
their products ^by the sense of touch.
The equipment of the new laboratory will in- clude three rnachinec suitable for groceries or mcrkets and one refrigerator designed for house- hold use. A detailed description of each of these machines with its advantages and tie field it cov- ers is given belov/. Together they cover this branch of foechanical refrigeration very thoroughly.
42
CREAMERY PACKAGE RT^FRlGSRATINrT SYSTSi TYPE G
The Creamery Package Manufacturing Company was one of the first to engage in the manufacture . of refrigerating machines. Their staff of service and installation engineers are the peer, in length of experience and ski'i.ljOf any similar organiza- tion in the country. In general design the machines are small and compact and take very little room for the tonnage developed. They are ideal for belt- ing direct to electric motors. The Type C repre- sents the best in tv/in cylinder vertical design for this caoacity. The wide popularity of these refrigerating systems is excellent testimony to the efficiency of this method. TAiile each unit has its own distinctive features, the ammonia com- pressor is of course the most important.
CP vertical ammonia compressors, "master-built are of the single acting, enclosed, self-oiling type. They are built of semi-steel and are designed f )r long and constant use. The bearings are exceeding- ly large and are readily renev/ed. A specially de-
'45
CREAITTIRY PACICAG-E COMPRESSOR
44
signed fly-v/heel, halving the spokes at the side of th.e rlrn, brings the center of tlie weight over the bearing, v/hlch Is the stuffing box gland. This gland has a bracket support from the base of the machine thus avoiding the use of an outboard, bear- ing on the compressor shr.ft beyond the fly-Y/heel. The crank shaft has tv/o bearings. All bases are cast with a sediment pocket at the bottom to keep the oil ;: s clean as posfjible.
These compressors are provide! vrith a scale trap on the suction line, and also have a gas trap in tjie suction line In the cylinder, providing a large supply of gas to drav/ on v/hen the cylinder is being refilled on the suction stroke. All mach- ines are provided v;ith by-passes for reversing the operation and. pu.mping out all pi',rts of the systen for repairs. These machines are provided v/ith saf- ety devices Avhich viill prevent liowlng gaskets in case the com'iressor is started up v/ithout opening the discharge valve. Suction gas pockets are con- nected to the base of the machine so that any oil coming back to the machine is e-utomatically trap-
45
CREAI.iERY PACKAGE REFRIGERATING I.'IACHINE
Sice \^i£rv\<
CREAMERY PACKAGE REFRIGEI^TILTC- imCHiWE
46 "ped in the base of the compressor.
The C? verticc.l compressor is deslsned viith a double trunk piston, the bottom pi.rt serving as a cross-head aiid the upper part servinrr as the piston proper. Both are provided v/ith rings and equinpei vjith mutiple poopet valves. The valve lift is quick and the opening is large- The valves are made of tool steel.
This compressor h:.s no clearance at high speeds. Its cylinders have safety heads which are perfectly flat on the bottom and its pistons are perfectly flat on top. The piston of this compress- or can be adjusted for clearance by shimming up the crank pin boxes- Hence at every revolution all the gas which has been drav/n into the cylinder is compressed and completely discharged. Because of this non-clearance feature the GP compressor oper- ates at the same high efficiency at low tempera- tures -s it does Y/hen operating at high tempera- tures .
47
C01'ITII\TEMTAL REFRIGERATING- SYSTEI;!
Continental machinery is designed and man- ufactured v.'ith the one idea, that dependable and satisfactory service is remembered long aftei" price is forgotten. For durability and econofiiy their line of refrigerating machinery is excelled by none. The continental self-contained refriger- ating unit combines the entire high side in one machine.
The continental is a cerni- enclosed machine. In operating it there is no ammonia in the crank case to nix with the lubricating oil. -he ammonia Is taken directly into the cylinders througii the pipe manifold. Therefore there is no possibility of pumping lubricating oil from the crank case over into the cooling coils- Flooding of the cool- ing coils with oil a,nd thereby cutting their re- frigerating effect is impossible.
Any part of the continental may be inspected by simply closing the suction and discharge stop valves on the manifolds, and removing the crank
48
CONTIIIENTAL REFRIGERATING SYSTEM
49 case door, the plates of the cylinder nec':s,and the cylinder heiA.
The continental 1b built with. a crocs head similar to that of a steam enj^ine. This causes a straight vertical movement of the piston which prevents side thrust on the cylinder vralls.
The stuffing box betv?een the cylinder and the crank ca.se prevents the ammonia from entering the craiilr case. This stuffing box is of special design and is pa.cked v/ith 3. combination of fric- tionless packing, one side of which is in contact v;ith the piston rod, and a diagona^lly shaped flex- ible packing which contracts and expands accord- ing to the pressure exerted upon it.
One of the best features of the continental is the adjustment for clearance. This is accomp- lished bymeans of a lock nut and threaded piston rod.
The shaft is made of a solid steel forging, very liberally proportioned, giving ample strength and assuring continuous service.
The continenta.l is equipped v/ith feather weight suction and discharge valves. All valves
50
and their seats are easily removable for grindin^j.
Safety heads are provided to prevent the possibil- ity of an accident in case of a charge of liquid being C8.rried over into the cylinder.
The lubrication is automatic. The crank case oil lubricates the main bee^rin^s, the connecting rod bearings, and the cross-head. The oil from the mechanical lubricator is pumped directly into the space in the stuffing box which is occupied by the spring. Ammonia in the cylinder acts as a par- tial lubricant and the piston rod,v;orking in a bath of oil carries sufficient oil to the cylin- der to effect perfect lubrication there.
The condenser used in these units is of spec- ial compact design in which the condenser and the liquid receiver are combined. The co^nbina-tion is located in the base and is easily accessible through large liand holes.
51
LI?:.IA^! REFRICtERATING r.IACHINE
The Lipman Line has met with great favor among small merchants throughout the country be- Cc'.use of its compactness, smooth running, and econ- omj^. The Lipraan machine is full -automatic and many of the company's sales have been replacements of much larger hand operated machines. There is no longer any doubt but that the auto matic mach- ine is the most satisfactory solution of the small merchant's problems.
The Model T^'^O v;as chosen from the Lipman Line as a typical small-store automatic machine. This machine has a capacity of lOOOpounds of refriger- ation per day. The s-ntire high side is erected on a rigiil attra-ctive stand. All pai-^ts are easi- ly accessible. The control sv/itches are operated by an electrical contact exp^-nsion thermostat.
The compressor is vertical, single cylinder, and single acting. It is an enclosed type. It is belt driven by an electric motor. The belt tens- ion is kept constant by a counter weight.
An efficient oil separator is provided in
52
LIPLIAN REFRIGERATING- MACHINE
the high pressure 2^s line.
The condenser is of the shell and coil type; the cooling water runs through the coll and the ammonia flows through the shell counter current to the coolinf^, w?.ter.
54 THE ICELESS REFRIGERATOR
Housekeeping TiethodG have been completely re- volutionized in the past tvio decades. Llodern in- vention has turned the labor of the housekeeper into a real pleasure, -he electric stove starts and stops its cooking ;7ith a turn of a sv/it3h, the vacuum cle.,ner keeps the house spick and span and the electric washer takes the drudgery out of "blue "londay". And nov^ we have the iceless refrig- erator.
The iceless refrigerator is ecsentia-ly a machine for keeping food dry and at a constant temperature of thirty-eight to forty- four degrees Fahrenlieit. It is a scientific fact beyond argu- ment that food spoils rapidly due to gera grovfth at temperatures of fifty degrees or more. To prop- erly preserve food so that bacteria cannot flour- ish, the temperature must be kept beloy? forty-five degrees. The ordinary ice box is an inefficient and unsatisfactory food preserver because the tem- perature is always too high and because it for- ever varies with the varying quantity of ice and
the flucbuo.tion of outbade tern ^er'atures • The In- side temperature cannot be c.ntrolled.
A Frigidaire v/as selected as the laboratory's household Tiachiae. The Frigidairs Corporation is a division of -the G-eneral Motors Corporation. No Seles are made outside of the territory covered by Frigidaire service. The principle data concern- ing this refrigeratoi'' is given below.
5'' ■ FRIGIDAIRE • Model B-9
Total V/eiG^T-t - 855 lbs- '
Total Outside Volu:::e - 37.5cu. ft.
Total Inside Food Gapacit^^ - 9 cu. ft.
Exterior Dimensions - 25" x 39" x 67".
Interior Dimensions
Large Food Compartment - ■ 38 1l/l6 x 14 5/8
X 18 1/2, inches. Small Food Compartment - 15 1/8 x 16 1/2 X 18 1/2 inclies-
Total Refrigerating Capacity - 700 B.T.U./hr.
Type of Condenser - Water Coil.
Refrigerating Chamber - A jacketed expansion
unit or boiler filled vath brine made up of calcium chloi'ide and w-ter- This brine tanlc vreighs about one hundred pounds when charged.
Brine Tanl^ Temperature - Average 20 degrees F. It is controlled by a methyl chloride fill- ed gas thermostat which stops the compressor at 16 degrees •: nd starts it at 24 degrees. This control is located in the brine tank.
57
Model "B.9'
1 . Ice Drawers
2 . Temperature Damper
3. S;-nltary Lining
4. ?/ater Control
5« Shelves
6. Storage Space
7 . Rubber Seals
8. Starting Control
58
Ice Making - Thi-ee trays of ''hree pounds cap- acity are recessed into the brine tank. The maximum time of freezing is eight hours; the cost is about one ce.it for tv;enty four cubes .
Compressor - T\70 cylinder, piston type, driven
through four to one gear reduction by a 1/4 horae power motor.
Pood Compartment Temperature - 33 to 44 degrees.
Pood Compartment Control - Thermostatic damper, controlling circulation of air.
Percent Operating Time - 20 to 25,^
Normal I.Iotor Load - 250 v/atts.
Cost of Electricity - About 6</. a day @ 4^ per Kilowatt hour.
Quantity of Water Usod - About 20 cu.ft. per day.
Cost of Water - 'i)4.38 per year 3 60^2'' per 1,000 cu, ft.
^9
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