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CHAPTER XXIII 



To reduce these figures to a pound of mill bagasse containing 55 per cent, 

 dry matter and 45 per cent, water, all that is necessary is to multiply by 

 0*55 and to add 0-45 lb. to the water, whence the following results are 

 obtained in terms of a pound of mill bagasse : — 



Pounds, per Pound of Bagasse 



At a temperature of o** C. and 760 mm. pressure, the volumes of i lb. 

 carbon dioxide, water vapour, nitrogen, and oxygen, are respectively 8-i, 

 19 '8, 12-8, 11-2 cu. ft. At a temperature of 273° C. or 523° R, which may 

 be taken as representative of that prevailing in flue gases, these volumes 

 are doubled. The volumes of the products of combustion of i lb. of mill 

 bagasse may then be estimated : — 



These results may be used to compute the required diameter of chimneys 

 or areas of flues. Engineering practice allows a velocity of 20 ft. to 30 ft. 

 per second to the waste gases. It is also customary to take the effective 

 diameter of a chimney as four inches less than the actual diameter. 



Temperature reached in Combustion of Bagasse. — One pound of dry 

 bagasse of the typical composition aflords on combustion 8,350 B.T.U. 

 with the exact quantity of air for combustion. If the latter is at 32° F., the 

 temperature of combustion T will be found from the following equation : — 

 8350 = 0-58 [180 + 970 + 0-48 (r - 212)] + T (1-7 X 0-217) + T 

 (o-o6 X 0-48) + r (4-30 X 0-244), whence T = 4410. 



If the air is at t° F. instead of 32° F., the temperature reached will be 

 r + (i - 32). 



In this equation the latent heat of steam is taken as 970, and the specific 

 heats of steam, nitrogen, and carbon dioxide, as 0-48, 0-24 and 0-22. 



