s
MODERN GASWORKS PRACTICE
for. The grouping of these, together with the shape of the upper generators, can be best seen by referring to the sectional view.
The D-shaped portions of the generators are provided -with an outlet at the top, whilst the regenerators have ports which serve the purpose of both inlets and outlets. A single biast miet (the blow is a positive one) is provided midway be-tween the two generators, beneath the fire-bars. The inlet, therefore, does duty for either generator.
As theplants so far erected have been pri-marily put down with. the i d e a of making “ blue ” water gas, the method of operating them for this purpose will be first described. As-suming that the generators, both upper and lower, are charged up and that the heats have been got up, a blow is first of all arranged for by admitting the biast through the inlet shown in the centre of the plant. This current of
Fie. 464.—Smith’s “Double-Gas” Plant.
air then splits i n t o two streams and travels through both coke beds simultaneously as far as the nostrils. Owing to the valves at the top of the D-shaped generators being closed, the products of the blow cannot force an exit this way ; hence
they pass through the nostrils, traverse the regenerators, and finally pass into the air by means of the stack valves. In this way the fuel in the generators is brought