294 ANNUAL REPORT 
which the flame was not deflected at all, but followed the left side of the 
kiln throughout. In this manner he succeeded in increasing the output 
from 140 to 200 barrels per day and the coal consumption was lowered 
from 138 to 110 pounds per barrel. ‘The saving in kiln repairs also was 
quite striking, it being reduced to two repairs per year. Likewise the 
Fig. 51. View along the s'de of a rotary kiln, showing the coal-dust storage tank, and 
pipe through which the dust is being blown into the furnace. The cement- 
batch tanks in the distance at the other end of the kiln. 
formation of rings, the wet method being used, was reduced to a mini- 
mum, so that the kiln could be operated for two weeks without stoppage 
on this account. 
Coal Used. —The kind of coal used is of great importance inasmuch 
as it must contain the proper amount of volatile combustible matter in 
order to ignite quickly, at the proper distance, so that the maximum tem- 
perature is produced at the right point, about 10% feet from the lower 
i eos ies 0 
