Washing and purging apparatus for liquid seals

Claim 1

In combination with a liquid seal for preventing the flow of a contaminated hot gas through a conduit, the seal having a first duct means communicating with a gas supply conduit and defining a first plenum chamber, a second duct means communicating with a gas exhaust conduit and defining a second plenum chamber, said first and second duct means cooperating to define a generally horizontal passageway interconnecting said first and second plenum chambers at the lower ends thereof and means for admitting a liquid into said seal to a level completely immersing said passageway, the improvement which comprises: a. an inclined generally rectangular plate forming the bottom of said interconnecting passageway; b. drain means disposed in the lower portion of said duct means adjacent the lower end of said inclined bottom plate, said drain being selectively operable to an open or closed position to drain liquid from or retain liquid in said seal respectively; c. at least one series of nozzles positioned adjacent the upper side of said inclined plate, a portion of the nozzles in each of said series being angularly directed toward the opening in said drain means whereby liquid ejected from said nozzles is directed toward said drain opening; d. means for selectively supplying a liquid to said nozzles at a flow rate sufficient to maintain the normal liquid level in said seal when said drain means is in an open position; whereby when said liquid seal is filled to its normal level, said drain means is actuated to an open position, and said nozzle supply means is operating, a sluicing operation is performed on the inclined bottom plate of said liquid seal without requiring the gas tight seal to be broken.