Centrifugal separation apparatus

Claim 1

In a wet-wall, falling film centrifugal separation apparatus for centrifugally separating entrained black liquor and woodpulp from a gaseous effluent stream from a woodpulp digester, said apparatus comprising a generally frusto-conical shaped tubular housing terminating at the larger end in a bottom wall and having an upper smaller end opposite said bottom wall, said tubular housing having a first outlet for de-entrained liquids and solids positioned near said bottom wall, a second outlet for gaseous components positioned at or adjacent said upper end, and a tangential inlet for said gaseous stream positioned between said first outlet and said second outlet, said tangential inlet extending transversely to the axis of said tubular envelope; the improvement which comprises a diaphragm positioned radially within said housing between said first outlet and said tangential inlet, said diaphragm having a relatively smooth unobstructed upper surface and an aperture in the form of a substantially radial slot, said slot being in a zone of relatively low gas velocity removed, in the direction of flow of said gaseous stream, from the tangential inlet by a major portion of said upper surface, the periphery of said diaphragm extending to the conical wall of said housing thereby partitioning said housing into two zones and defining: a. an unobstructed settling chamber in that zone between said diaphragm and said bottom wall; and b. a de-entrainment chamber in that zone between said diaphragm and said upper end with the tangential inlet positioned adjacent the diaphragm, said aperture in said diaphragm communicating between the chambers, said aperture extending from adjacent the periphery of said diaphragm to adjacent the center and being sufficiently large and unobstructed by protrusions to continously pass black liquor and de-entrained woodpulp therethrough, whereby centrifugal separation of black liquor and woodpulp is achieved in said de-entrainment chamber, and black liquor and woodpulp collecting thereon pass therefrom into said settling chamber through said aperture.