.......... 70,430
10-1/2 lb. ashes left, say at 500 deg................ 1,129
---------
Total work actually done.............. 1,927,459
Unaccounted for.................................. 26,521
---------
Calculated available work........................ 1,953,980
The unaccounted-for work, therefore, amounts to only 11/2 per cent.
of the calculated available work.
Sir Frederick Bramwell ingeniously arranged his data in the form
of a balance sheet, and showed 253,979 units unaccounted for; but
if from this we deduct the work lost in displacing the air, the
unaccounted-for heat falls to less than 4 per cent. of the total
heat of combustion. These results show how extremely accurate the
observations must have been, and that the loss mainly arises from
convection and radiation from the boiler.]
The data necessary for our purpose are:
Steam pressure 80 lb. temperature 324 deg. = 784 deg. absolute.
Mean temperature of smoke 389 deg. = 849 deg. "
Water evaporated per 1 lb of coal, from and at 212 deg. 11.83 lb.
Temperature of the air 60 deg. = 520 deg. absolute.
" of feed water 209 deg.
Pages:
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39