| 摘要 |
A method of increasing the cross-flow filtration flux of a liquid through an elongated porous filter tube, comprising the steps of flowing a portion of the liquid transversely through the filter tube wall by establishing a pressure differential across the filter tube wall, and maintaining the filtration flux rate transversely through the filter tube wall at substantially the same value along the entire length of the filter tube during filtration. Typically, the portion of the liquid exiting from the downstream end of the filter tube is recycled back to the feed end of the filter tube via a return line having a recycle pump operatively connected thereto, and the filtration flux rate is maintained at substantially the same value along the entire length of the filter tube by pumping make-up of the liquid to be filtered into the return line at a point between the downstream end of the filter tube and the recycle pump connection, whereby the pressure drop measured between a point immediately upstream of the feed end and a point immediately following the downstream end is approximately zero during filtration. Apparatus for increasing the cross-flow filtration flux of a liquid through an elongated porous filter tube comprises an elongated porous filter tube, means for flowing the liquid into the tube and for flowing a portion of the liquid transversely through the filter tube wall, including means for establishing a pressure differential across the filter tube wall, and means for maintaining the filtration flux rate transversely through the filter tube wall at substantially the same value along the entire length of the filter tube. Broadly, the apparatus of the invention preferably further comprises a recycle line fluidly connected between the outlet and the feed end of the filter tube, a recycle pump operatively connected to the recycle line for recycling the portion of the liquid exiting from the outlet back to the feed end, and the means for maintaining the filtration flux rate at substantially the same value along the entire length of the filter tube includes a make-up pump operatively connected to the recycle line at a point between the tube oulet and the recycle pump connection for pumping make-up of the liquid to be filtered into the recycle line, thereby maintaining the pressure drop measured between a point immediately upstream of the feed end a point immediately following the outlet at approximately zero during filtration. |
