Apparatus and a method for using permeate to flush a reverse osmosis filter

A method of using permeate to flush a reverse osmosis filter membrane in the same direction of flow as when fluid is being filtered by said membrane, the method comprising the steps of:

• a) routing pressurized, untreated fluid through a housing having a reverse osmosis filter membrane positioned therein and having an inlet side and an outlet side, said membrane having an interior surface and an exterior surface, said housing having an inlet port located outward of said exterior surface of said membrane at said inlet side of said housing, and a first outlet port and a second outlet port both located at said outlet side of said housing, said first outlet port located outward of said exterior surface of said membrane and said second outlet port located inward of said interior surface of said membrane, said untreated fluid passing through said membrane to produce permeate;
• b) routing said permeate through said first outlet port to a storage tank, said storage tank holding from between 100 gallons to 5,000 gallons of permeate;
• c) stopping the flow of said untreated fluid to said housing;
• d) routing permeate from said storage tank to said inlet port of said housing and passing said permeate along said exterior surface of said membrane to remove solids and passing the remainder of said permeate through said membrane to flush said membrane, said permeate now containing solids producing a flush fluid;
• e) routing said flush fluid to a drain through said first outlet port;
• f) allowing said permeate to immerse said membrane for at least about 5 minutes at zero pressure to resorb solids from said membrane and form additional flush fluid;
• and
• g) flushing said additional flush fluid out of said housing and through said first outlet port to said drain using additional permeate.