Method and apparatus for recirculating tangential separation system

A feed fluid treatment apparatus, comprising:

• a tangential filtration device having an inlet to receive the feed fluid and configured to separate the feed fluid into a permeate fluid that is substantially free from contaminants, and a concentrate fluid wherein the contaminants removed from the feed fluid are concentrated;
• a concentrate fluid circuit configured to receive the concentrate fluid exiting the tangential filtration device and to circulate the concentrate fluid back to the inlet of the tangential filtration device, and to mix the circulating concentrate fluid with the feed fluid prior to the tangential filtration device, effectively increasing the concentration of the concentrate fluid;
• a monitoring device configured to monitor the concentrate fluid and initiate purging of the apparatus when the predetermined concentration of the concentrate fluid is reached;
• a purge system configured to purge the apparatus of the concentrate fluid when the predetermined concentration of the concentrate fluid is reached;
• an inlet configured to admit feed fluid to be added to the circulating concentrate fluid to replace the amount of permeate fluid permeating said tangential filtration device and to replenish the apparatus with fresh feed fluid as the apparatus is purged of the concentrated circulating concentrate fluid.

A filtration method, comprising:

• filtering raw water through a reverse osmosis filter system into permeate fluid and concentrate fluid;
• recirculating the concentrate fluid to the raw water prior to the reverse osmosis filter device;
• and
• purging the reverse osmosis filter system with permeate fluid when the concentrate fluid reaches a predetermined concentrate level.

A filtration device, comprising:

• a raw water inlet to receive raw water;
• a reverse osmosis filtration system configured to filter the raw water into permeate fluid and concentrate fluid;
• a recirculation system coupled to the reverse osmosis filtration system to receive the concentrate fluid and mix the same with the raw water prior to the reverse osmosis filtration system;
• a delivery system configured to receive the permeate fluid and deliver final product to a product outlet.