Stoppages and Cleaning.—After closing the gas-inlet to the engine, the damper in the gas-outlet flue of the generator should be opened and the cocks controlling the feed of water to the scrubber and to the vaporizer should be closed.
If it is desired to keep up the fire of the generator during the stoppage so as to be able to start again quickly, the ash-pit door should be opened so as to produce a natural draft which will maintain combustion. While the door is open, the clinkers which have accumulated above the grate may be removed, as they are much more easily taken off the grate when they are hot.
At least once a week the fire in the generator should be put out and the generator completely cleaned—that is, when ordinary fuel is employed. For this purpose, as soon as the apparatus is stopped, a portion of the incandescent fuel is withdrawn through the doors of the combustion-chamber, and the retort is allowed to cool before it is emptied entirely. Too sudden a cooling of the retort may injure its refractory lining. In order to prevent explosions caused by the entrance of air, the feed-hopper should remain hermetically closed during the removal of the incandescent fuel through the doors of the combustion-chamber.
If the apparatus is placed in a room poorly ventilated, the cleaning should be attended to by two men, so that one may assist the other in case he is overcome by the gas. In all cases there should be a strict prohibition against the use of any light having an exposed flame liable to set on fire the explosive mixtures which may be formed.
When the generator, after cooling, is completely open, the charging-box is taken apart, and, if necessary, the feed-hopper also; the grates are taken out, if necessary;
and, by means of a poker inserted from above, the clinkers and slag adhering to the retort are broken off.
In the foregoing paragraphs the author has indicated how the several apparatus, such as the vaporizer, the washer, the conduits, etc., should be attended to and maintained in good working order.