(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Biodiversity Heritage Library | Children's Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "The Flow Of Gases In Furnaces"

352

APPENDIX X


	Steam Atomizing
		Air Atomizing
	
	Calories per Kg-
	B.t.u.
 per Lb.
	Calories per Kg.
	B.t.u. per Lb.

Heat released by oil                    .   .   .
	10,400 1,960
	18,720 3,528
	10,400
 1,850
	18,720 3,330

Heat carried to stack at 400  C . (752 F.) Difference available in boiler .
				
	8,440
	15,192
	8,550 110
	15,390 198

Difference in favor of air atomizing . .
				
F. lower, due to firebox construction. In fact, much lower tem-
peratures may be obtained under unfavorable conditions. Similar
methods to the above make these curves and the volumetric data
in Tables 11 to 21 extremely useful in designing furnaces for a
particular fuel.

Several systems are in use for preheating the air for boilers on
ships and on land. The temperature drop of the waste gases
ranges from 70 C. (126 F.) to 120 C. (216 F.). The tempera-
ture rise in the air ranges from 60 C. (108 F.) to 105 C. (189 F.).
These curves may be utilized to approximate the effect of such
preheat:

Steam or Air Atomizing


	Calories per Kg.
	B.t.u. per Lb.

Heat in 120 per cent air supply at 120 C. (184 F )                . .            .........
	420
	756


	
	

This will result in an increase in calorific intensity of about 50 C.
(90 F.). This extra heat will be utilized at boiler efficiency in
producing steam. Preheating of the oil supply to secure fluidity
results in a slight addition to the heat available.
The ruling temperature of a heating operation is the tempera-
ture to which the material being heated must be raised in order to