| 摘要 |
PCT No. PCT/FI94/00485 Sec. 371 Date Jun. 1, 1995 Sec. 102(e) Date Jun. 1, 1995 PCT Filed Oct. 27, 1994 PCT Pub. No. WO95/12446 PCT Pub. Date May 11, 1995A cross-flow filtration apparatus is able to produce cleaner liquid, especially in the filtration of green liquor, then is typically possible. A housing contains a number of vertical filter elements each having a filter surface with first and second sides which are substantially free of filter cake. A higher gas pressure is provided on the first sides of the filter surfaces than the second sides, and filtered liquid passes through the filter surface from the first side to the second side. A first conduit withdraws filtrate from the second side of at least one of the surfaces, and a second conduit withdraws suspension liquid from adjacent the bottom of the filter elements and typically (though not necessarily) recirculates it. Suspension is introduced-such as in a tray with a perforated bottom mounted above the filter elements, and/or the nozzles-so that the suspension flows in a falling film down the first sides and in contact with them, so that filter cake does not form during operation. A sludge vessel is typically connected to the second conduit external of the housing, and an open dregs vessel distinct from the sludge vessel may be connected to a bottom portion of the housing.
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