| 摘要 |
PCT No. PCT/GB94/00132 Sec. 371 Date Jul. 20, 1995 Sec. 102(e) Date Jul. 20, 1995 PCT Filed Jan. 24, 1994 PCT Pub. No. WO94/17892 PCT Pub. Date Aug. 18, 1994A slurry is subjected to a filtration and washing process in order to separate the liquor from the solids. The filtration and washing process is carried out in a housing (101) enclosing an inert gaseous atmosphere which also passes through the filter cake and may be recycled, after treatment, to remove contaminants therefrom. To prevent recontamination of the filter cake as a result of the recycled gas entraining contaminant vapors within the housing (101), the gas is introduced into the housing (101) at a downstream location (152a, 166) relative to the direction of travel of the filter cake on a movable filter medium (100) and in such a way as to develop a contaminant concentration gradient whereby the cleanest cake is contacted by gas having the lowest contaminant level. |
