THE COMPLETE GASIFICATION OF COAL
761
Thermal efficiency of process =
28,449,900
34,973,100
X 100 = 81-3 per cent.
m, 1 æ • t J x- 8,010,000 _
1 henna 1 emciency oi gas production — —------—X 100 — 55-1 per
14,533,200
cent.
Thermal Efficiency of “ Blue ” Water Gäs Production
Heat Supplied. B.Th.U. Heat Recoveked. B.Th.U.
1 ton of coke at 12,100 B.Th.U. 60,000 c. ft. “blue” gas at 300
per 1b = 27,000,000 B.Th.U. per c. ft. . . . — 18,000,000
750 1b. of coke for steam in gener- 9| 1b. free sulphur at 4,100
ator and driving fan, etc., at B.Th.U. per 1b = 38,960
12,100 B.Th.U. per 1b. . . = 9,075,000 —
Total recovered .... 18,038,950
B.Th.U. used and lost 18,036,050
Total 36,075,000 Total 36,075,000
i f 18,038,950 inn
iliermal emciencv oi process =----------------X 100 = 50'0 per cent.
1 36,075,000 1
18 y 106
Thermal efficiency of gas production =------------x 100 = 49-9 per cent.
36,036,050
If the sensible heat of the blow gas and the combustibles therein are made use of after leaving the generator and are employed in a steam boiler, then the efficiency of gas production becomes—
I« y 106
100 = 66-8 per cent.
In calculating the thermal efficiency of complete gasification the figures taten for yield of products must naturally be more or less hypothetical, for at the present stage no really consistent results can be referred to. In view, however, of the considerable experience of H. Strache as an inventor and operator of plants of the kind it is admissible to assume tliat the yields he has obtained in practice (tar was found to yield 6-8 per cent, of the heat of the coal) approximate fairly closely to the results which. might be generally expected under good working conditions. In the following balance Strache’s gas and tar yields 1 are taken, while ammonia and recovered fuel as sources of heat have been neglected.
1 See page 767.