摘要 |
A fixed bed gasifier has an annular series of spaced pokehole units thereabout, each unit of which is an outwardly and upwardly extending tapered tube with an end closure having an eccentrically positioned hole through which a poker may be inserted to pass through the unit for poking the fire zone of the gasifier. The tapered tube opens the gasifier vessel at the reduction zone. The hole at the end closure is closed when not in use by a movable closure that is opened only when the poker is to be inserted. The movable closure is connected with an air valve that admits atmospheric air from a manifold encircling the gasifier, at a pressure slightly above the internal pressure in the gasifier, to the interior of the unit as the movable closure is operated to expose the hole at the end of the unit, forcing hot gases in the unit back into the gasifier in the reduction zone, and permitting air only to blow out the end of the unit just before the poker may be inserted and until the pokehole is again covered. |