A. O. Smith Corporation
HIGH WATER EFFICIENCY TDS CREEP SOLUTION

Abstract:

A water purification system includes a tank which stores permeate during periods of standby during which impurities can migrate across a filtration membrane, resulting in impure water on the downstream side of the membrane. During an initial portion of a water draw immediately following a period of standby, the impure water on the downstream side of the membrane is used as a motive fluid to force the permeate out of the tank for delivery to the faucet. Permeate is provided on a continuous bases directly from the membrane to the faucet after the tank is depleted of permeate. The system includes a control system and a plurality of valves to recycle the impure water used as a motive fluid to the membrane to produce permeate. At the conclusion of a water draw, the tank is filled with permeate and the system enters a period of standby until the next water draw.