Hollow fibre filter cartridge and header

A bank of filter units wherein each filter unit comprises:

• (i) an elongated open-ended casing having transfer ports adjacent each end thereof to provide fluid communication between the outside and inside of the casing,
• (ii) a bundle of hollow, porous, polymeric fibres within the casing,
• (iii) a first plug at one end of the casing in which one end of the bundle of fibres is embedded whereby the plug prevents flow of fluid out said one end of the casing other than through the lumens of the fibres,
• (iv) means for preventing substantial flow of fluid out of said casing other than through the lumens of said fibres within said casing and which includes a second plug closing the other end of the casing for preventing the flow of feed through the end of the casing,
• (v) a first transfer header at said one end of the casing and including:
• (a) a body portion that encloses said one end of the casing,
• (b) a feed passageway extending through said first header having an inlet at one end for receiving feed to be treated, an outlet at the other end adapted to be connected to the inlet of the feed passageway of an adjacent first header and a discharge port for delivering feed to the casing,
• (c) an inlet chamber in fluid communication with the discharge port of the feed passageway and the transfer port at said one end of the casing,
• (d) an outlet chamber for receiving filtrate from the open ends of the fibre lumens, and,
• (e) a filtrate passageway extending through said first header having a receiving port for receiving filtrate from the outlet chamber, an outlet at one end for discharging filtrate and a inlet at the other end adapted to be connected to the outlet of the filtrate passageway of an adjacent first header,
• (vi) a second transfer header at the other end of the casing and including:
• (a) a body portion that encloses said other end of the casing,
• (b) an outlet chamber for receiving treated feed from the transfer port at said other end of the casing, and,
• (c) a treated feed passageway extending through said second header having a receiving port for receiving treated feed from the outlet chamber, an outlet at one end for discharging treated feed and an inlet at the other end adapted to be connected to the outlet of the feed passageway of an adjacent first header and the filters are connected together by said headers so that the feed passageways and filtrate passageways are connected in series whereby each filter may be supplied from the one source of feed with a portion of the feed being introduced into the inlet chamber of each filter, the filtrate from each filter is directed to the interconnected filtrate passageways and the treated feed from each filter is directed to the interconnected treated feed passageways.

A method of operating a filter unit which utilizes fibre lumens and which comprises:

• (i) draining the fibre lumens of filtrate,
• (ii) terminating the feed flow with feed remaining on the feed side of the filter and applying gas to the lumens to pressurize the filter,
• (iii) releasing the pressure on the feed side of the filter while maintaining the gas pressure and while there is no flow of feed,
• (iv) resuming flow of feed and maintaining gas pressure in the lumens to carry substantially all of the accumulated detritus out of the filter,
• (v) removing the gas pressure from the filtrate side of the filter and filtrate allowed to refill the lumens, and
• (vi) pressurizing the filter so as to replace the gas in the pores of the membrane with liquid.