A. O. Smith Corporation
Water filtration system with recirculation to reduce total dissolved solids creep effect

Abstract:

A point-of-use water filtration system having an idle mode and a filtration mode, the water filtration system including a feed water inlet, a pump in fluid communication with the feed water inlet via a feed water line, and a semi-permeable membrane having an upstream side and a downstream side. A first portion of the upstream side is in fluid communication with a membrane inlet and a second portion of the upstream side is in fluid communication with the concentrate outlet, and the downstream side is in fluid communication with a permeate outlet. The point-of-use water filtration system also includes a permeate line in fluid communication with the permeate outlet and a filtered water outlet, a concentrate line in fluid communication with the concentrate outlet, a flow path configured to selectively connect the permeate line to the feed water line; and a controller configured to anticipate demand for the filtration mode based on operator habit information stored in a memory of the controller when the water filtration system is in the idle mode and to recirculate water in the permeate line through the pump and the semi-permeable membrane in response to the anticipated demand for the filtration mode.