Abstract: A reverse osmosis water purification system for providing potable water from a municipal water or other source containing undesired impurities. A motor driven pump supplies a feed stream to a reverse osmosis unit resulting in the creation of a product water stream and a concentrate or brine stream. The inclusion of a product water holding tank may be optionally omitted by routing the product water outlet stream directly to the tap via a branched line. A pressure sensor causes a solenoid valve to open when the withdrawal of water from the tap is terminated, opening a valve in the branch line leading back to the pump. The pump then continues to run, recirculating the product water stream to a mixing unit where it is blended with a major part of the concentrate stream that is being recycled and with make-up fresh water to create a composite feed stream.

Abstract: A water purification apparatus utilizing a reverse osmosis cartridge which supplies a measured amount of potable water to substantially fill an open top pitcher of known desired size. This free-standing apparatus includes an electric pump which withdraws water from an overhead reservoir and pumps it through prefilters and the reverse osmosis cartridge, from which a brine stream returns to the reservoir and a product water stream discharges from an overhead outlet above the pitcher. Control means monitors the level and quality of water in the reservoir and halts the operation of the pump as soon as the water level falls below a lower predetermined level which is set so that the desired measured quantity will have been delivered to the pitcher from a full reservoir. The control means also halts operation when the total dissolved solids content in the reservoir reaches a preset upper limit.

Abstract: Self-standing apparatus for filtering supply water to provide purified water includes a base subassembly and two container subassemblies. One container subassembly provides supply water to filtering apparatus located in the base subassembly. The second container holds purified water which passes through a semipermeable membrane filter in the base subassembly. Concentrate from the membrane filter flows back to the supply water container for ultimate recirculation. The base subassembly and the container subassemblies have automatically closing valves which render each container water-tight when separated from the base subassembly, and which open to provide communication between the containers and filtering apparatus within the base subassembly.

Abstract: A water purification system having a first pressure vessel containing a reverse-osmosis filter and a second separate pressure vessel containing an activated carbon prefilter operatively connected in series and upstream of the first pressure vessel by means of a common header. The activated carbon prefilter includes a particulate trap upstream of the activated carbon to trap sediment carried in the unpurified water. The particulate trap is compressible under operational water pressures attained in the system when the trap becomes clogged with sediment, which serves to crack or break away from the surface thereof particle accumulations clogging the trap, permitting flow to continue through the trap into the activated carbon and, subsequently, through the reverse-osmosis filter element.

Abstract: An over-the-counter, free-standing, water purification system including a pressure vessel that encloses a reverse-osmosis separator. Tap water at a pressure of between approximately 20 and 100 psig is introduced into the pressure vessel and a portion of the water is forced through the reverse-osmosis separator, while the remaining water is discharged from the pressure vessel along with the pollutants that are too large to penetrate the membrane of the reverse-osmosis separator. The product water passes through the reverse-osmosis separator at a rate of between approximately 5 to 100 milliliters per minute and is then post-filtered at a slow rate through a large amount of activated carbon, between approximately 10 and 1,000 grams, contained within the housing for the purification system.

Abstract: A reverse osmosis water purification device for attachment to a kitchen faucet or the like employs a substantially leak-proof, two-piece pressure vessel containing a readily replaceable reverse osmosis module. In the preferred embodiment, a handle is provided on the module to facilitate removal thereof from the pressure vessel. Also in the preferred embodiment, carbon-felt disks are provided to provide filtering for water after the water has been purified by reverse osmosis membranes.