25 - 7.50)/7.50 =
63 per cent. to (12.25 - 7.00)/7.00 = 75 per cent. higher than that of
anthracite.
_Spray injector._--Steam not superheated, being the most convenient for
injecting the spray of liquid fuel into the furnace, it remains to be
proved how far superheated steam or compressed air is really superior to
ordinary saturated steam, taken from the highest point inside the boiler
by a special internal pipe. In using several systems of spray injectors
for locomotives, the author invariably noticed the impossibility of
preventing leakage of tubes, accumulation of soot, and inequality of
heating of the fire box. The work of a locomotive boiler is very different
from that of a marine or stationary boiler, owing to the frequent changes
of gradient on the line, and the frequent stoppages at stations. These
conditions render firing with petroleum very difficult; and were it not
for the part played by properly arranged brickwork inside the fire box,
the spray jet alone would be quite inadequate. Hitherto the efforts of
engineers have been mainly directed toward arriving at the best kind of
"spray injector," for so minutely subdividing a jet of petroleum into a
fine spray, by the aid of steam or compressed air, as to render it
inflammable and of easy ignition.
Pages:
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41