Shaft furnace gas cleaning - with automatic by-pass of gas cleaning appts in event of appts failure

摘要

Furnace gas passes into a scrubber, through a Venturi and into a drier from which it is extracted by a blower to be vented up a first chimney. Above the scrubber is a second chimney with a valve and second blower should the venturi, drier or first blower or its associated choke fail, a controller opens the valve and switches on the second blower in order to vent gas up the second chimney. At the same time water is pumped into the scrubber. A second controller may then be used to ensure smokeless working of the furnace. This is done by sensing gas pressure at the hearth and directing hearth gas along a tube into the second chimney to by-pass the scrubber or if necessary lowering the furnace cover.