A WATER PURIFIER AND A PROCESS OF CLEANING THE MEMBRANE

摘要

The present invention provides a water purifier (200) comprising, a pump (203); a membrane module (205) where the membrane is spiral wound membrane including reverse osmosis, nanofilter, ultrafilter and microfilter membranes; a first valve (204) to control the water flow into the membrane module (205); and a permeate line for purified water and a reject line for discarded water; wherein the reject line comprises a valve (208); and wherein the water purifier comprises a closed chamber (209) and a second valve (210) in sequence downstream the membrane module (205) in the permeate line and wherein said reject line is downstream of said membrane module (205). The invention also provides a process for cleaning the membrane module (205) of the water purifier (200), said process comprising, operating the purifier (200) with the pump (204) powered and the first (204) and second valves (210) open; closing the second valve (210) to initiate shut-down of the purifier (200) and to allow a pressure build up in the closed chamber (209); allowing the pump (203) to continue operation with the first valve (204) open; and shutting off the pump (203) and the first valve (204) to force purified water in the closed chamber (209) through the membrane module (205) in the reverse direction until the pressure in the closed chamber (209) dissipates to