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US 4,784,771 AGranted
Method and apparatus for purifying fluids
AssigneeEnvironmental Water Technology, Inc.
InventorsRonald L. Wathen, Steven L. Miller
Life of this patent
Estimating the term…
Abstract
A method and apparatus for purifying and/or separating fluids including passing such fluid from a feed side of a reverse osmosis unit to the product side of such unit and to an ultimate user during a purifying cycle and recirculating residual fluid back to the feed side in bypass relation to the reverse osmosis unit during a treating cycle to introduce suitable treating fluids into the system for disinfecting and rejuvenating the system.
Claims39
A method of purifying fluid utilizing reverse osmosis comprising:
- passing fluid to be purified during a purifying cycle through an open ended feed zone, through a reverse osmosis zone to an open ended product zone and to an end user for a preselected time period;
- interrupting said purifying cycle after said preselected time period by closing said feed and product zones and recycling residual fluid in by-pass relation to said reverse osmosis zone from said product zone in direct, continuously circulating flow to said feed zone for a preselected time period during a treating cycle;
- and,
- introducing treating fluid from a treatment zone in direct, continuously circulating flow into the recycled fluid during said treating cycle to continuously disinfect/rejuvenate and flush said reverse osmosis zone throughout.
1 more element
A method of purifying fluid utilizing reverse osmosis comprising:
- passing fluid to be purified during a purifying cycle for a time period of approximately three (3) to four (4) hours through an open ended feed zone, through a reverse osmosis zone in shearlike relation with the feedside thereof to an open ended product zone and to an end user;
- interrupting said purifying cycle at the end of said time period by closing said feed and product zones and recycling residual fluid in by-pass relation to said reverse osmosis zone from the product zone to the feed zone;
- introducing an osmotically active formaldehyde solution having a rejection range of approximately 38% to approximately 50% with respect to the reverse osmosis zone to allow residual fluid to osmotically pass from said product zone through said reverse osmosis zone to said feed zone for a period of approximately one to two minutes to an equilibrium stage, said equilibrium stage lasting for a suitable preselected period of time;
- passing a flushing fluid at a controlled rate equal to passing said fluid simultaneously to a drain zone through said reverse osmosis unit from said treatment and feed zone to said product zone and recycling same back to said feed and treatment zone for a suitable preselected period of time;
- repeating said treatment and flushing step with a solution of hydrochloric acid having a rejection range of approximately 97% to approximately 99% with said initial treating stage lasting for a preselected period of time to equilibrium state and said equilibrium state lasting for a suitable preselected period of time;
- passing an osmotically inactive sodium hydroxide solution in similar fashion as said flushing solution but without draining through said zones for a suitable preselected period of time;
- and,
- repeating said flushing cycle.
5 more elements
A fluid purification apparatus comprising:
- a primary flow conduit having spaced upstream fluid feed inlet means and downstream fluid product outlet means;
- a reverse osmosis means disposed in said primary flow circuit between said fluid feed inlet means and said fluid product outlet means to include a feed side and a product side;
- motive means communicating with said primary flow conduit to enhance fluid flow from said feed inlet means through said reverse osmosis means to said product outlet means;
- treatment means connectable into said primary conduit to selectively introduce separate treating fluids into said primary flow conduit to treat said reverse osmosis means;
- and
- a secondary flow global loop conduit connectable to extend parallel said primary flow conduit in by-pass relation to said reverse osmosis means to communicate in direct, continuously circulating flow between said product outlet means and said feed inlet means of said primary conduit and with said treatment means to continuously treat said reverse osmosis means throughout when a separate treating fluid is selectively introduced into said treatment means.
3 more elements
A fluid purification apparatus comprising:
- a primary flow conduit having spaced upstream fluid feed inlet means and downstream fluid product outlet means;
- a reverse osmosis means disposed in said primary flow conduit between said fluid feed inlet means and said fluid product outlet means to include a feed side and a product side;
- said primary flow conduit successively including downstream of said feed inlet means and before said reverse osmosis means, a carbon treating tank, a rinse control valve having a flow control restrictor parallel thereto, a prefilter, and a recirculating valve;
- said primary flow conduit further including solvent drain control means and pressure limit control means on both feed and product sides of said reverse osmosis means to selectively open each of said drain control means when preselected fluid pressure levels have been reached in the primary circuit on each side of said reverse osmosis means and also including a conductivity/resistivity monitor means on said product side of said reverse osmosis means to open said drain control means when fluid current conductivity/resistivity conditions in said primary circuit reach a preselected level;
- pump means positioned in communicative relation with said primary conduit as part of a secondary nested closed loop treating conduit nested in parallel relation with said primary conduit before said recirculating valve and said feed side of said reverse osmosis means;
- treatment means communicating with said primary conduit through quick connect fittings on opposite sides of said recirculating valve, said treatment means including a vented treating fluid container having inlet and outlet conduits communicating with said primary flow conduit through said quick connect fittings and further including an inlet sensing and control valve sized to provide a preselected flow restriction and an outlet check valve in said container to regulate flow of fluid through said container to said primary conduit and through said drain control means in accordance with fluid level in said container;
- and,
- a secondary flow global loop conduit having quick connect fittings, at opposed ends thereof connectable to primary conduit fittings to extend parallel said primary flow conduit in by-pass relation to said reverse osmosis means to communicate directly between said product outlet means and said feed inlet means of said primary conduit and with said treatment means to flush said reverse osmosis means when a separate chemical treating fluid is selectively introduced into said treatment means, said primary flow conduit having quick connect fittings upstream said feed side of said reverse osmosis means and said prefilter and downstream said conductivity/resistivity monitor means on said product side of said reverse osmosis means to cooperate with quick connect fittings of said secondary flow loop conduit to allow placing of said secondary global loop conduit in by-pass relation to said reverse osmosis means, said quick connect fittings in said global loop including means to render said current conductivity/resistivity detection means inoperative with respect to drain when said secondary flow loop conduit is connected to said primary conduit in by-pass relation to said reverse osmosis means.
5 more elements
Dependencies are inferred from the claim text.