| 摘要 |
The filter system includes a plurality of porous metal filter tubes and is used in a method for extracting high purity solid para-xylene crystals from a mother liquor feed slurry of mixed xylenes in liquid and crystal form utilizing a separation unit which includes a crystallization stage where the mother liquor slurry is cooled in at least one crystallizer to crystallize liquid para-xylene into solid crystals, an isomerization stage where xylenes, such as ortho-xylene and meta-xylene, are reacted over a catalyst bed to convert these xylenes into para-xylene, and a distillation stage where the mixed xylenes are separated from the impurities from which byproducts are obtained. The method includes the steps of diverting and circulating some of the liquid crystal slurry from the crystallizer through a filter system and back to the crystallizer while at the same time extracting some of the liquid crystal slurry and supplying same to a centrifuge where solid crystal para-xylene is extracted from the liquid crystal slurry; and extracting essentially solid-free liquid from said filter system and supplying said to the isomerization stage thereby to increase the amount of solid para-xylene crystals extracted from the centrifuge over a given period of time.
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