HEAT CONSUMPTION AND HEAT UTILIZATION. 



507 



"The kiln turns out an average of 3635 Ibs. of clinkered cement 

 per hour from 5980 Ibs. of material fed to it, producing 200 Ibs. of flue- 

 dust; equal to 3.35 per cent of the weight of mixture charged. The coal 

 used averages 110 Ibs. per barrel of cement produced." 



The temperature of the clinker falling out of the lower end of the 

 kiln was measured by the Le Chatelier pyrometer, and determined to 

 be 1200 C. = 2192 F. The temperature of the waste gases, deter- 

 mined 4 feet below the top of the stack, was 820 C. or 1508 F. The 

 sensible heat in the clinker (leaving the kiln at 1200 C.) was determined 

 by a calorimeter as 290 kilogram calories per kilo =522 B.T.U. per 

 pound. The waste gases in the stack analyzed as follows: 



Carbon dioxide 10 . 2 



Oxygen 11.8 



Carbon monoxide 0.2 



Sulphur dioxide not determined 



Water 



Nitrogen 



It will be noted that part of these preliminary data were deter- 

 mined by direct experiment, while others apparently are "averages," 

 or otherwise of less value than experimental results. This, unfortu- 

 nately, throws doubt upon some of the results obtained, as noted below. 

 At the close of his paper, after making the necessary calculations, Mr. 

 Richards summarized his results. This summary, recalculated to 

 calories and B.T.U. per barrel, is presented below. 



TABLE 192. 

 SUMMARY OF RICHARDS' TESTS OF ROTARY KILNS. 



Heat-units per Barrel. 



