Pumps for filtration systems
First Claim
1. A membrane filtration system comprising:
- a first piston, said first piston separating a feed chamber from a retentate chamber;
a membrane filtration element; and
a differential pressure activated (DPA) valve which controls retentate discharge, said DPA valve disposed downstream of said membrane filtration element and said retentate chamber with respect to a flow of retentate, said DPA valve comprising;
a single housing comprising a port in fluid connection with an inlet to said filtration element, an inlet port for receiving retentate from said filtration element, and a retentate discharge port; and
a single second piston slideably disposed within said single housing, said second piston positively sealing said inlet port when a feed pressure on a first face of said second piston exceeds a retentate pressure on a second face of said second piston;
wherein pressure recovery is provided by a pressure difference between the feed chamber and the retentate chamber acting on said first piston.
8 Assignments
0 Petitions
Accused Products
Abstract
Improvements in product water throughput from a reverse osmosis (RO) membrane filter achieved by thinner feed spacers in the RO element, enhanced recovery (ratio of permeate to feed), pressure recovery of the retentate fluid pressure opposing the feed water pressure, and fluid pulsing of the RO element feed stream. The system of the invention preferably comprises a dual head reciprocating pump, an RO element, and a differential pressure activated (“DPA”) valve. The DPA valve, in combination with connecting the two pump heads to reduce required pump pressures, generates energy recovery. The frequency and amplitude of the reciprocating pump create a pulse wave in the RO element that improves permeate quality and throughput. A control system preferably monitors system parameters to optimize the reciprocating pump speed and amplitude in order to obtain maximum throughput and permeate quality from any given RO element configuration. Also a highly compact, portable RO system comprising a piston and a DPA valve. The piston separates the feed chamber from the retentate chamber. The pressure difference between the two chambers determines the pressure recovery of the system. The DPA valve opens and closes hydraulically to automatically control the retentate discharge as the system is pumped.
97 Citations
30 Claims
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1. A membrane filtration system comprising:
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a first piston, said first piston separating a feed chamber from a retentate chamber; a membrane filtration element; and a differential pressure activated (DPA) valve which controls retentate discharge, said DPA valve disposed downstream of said membrane filtration element and said retentate chamber with respect to a flow of retentate, said DPA valve comprising; a single housing comprising a port in fluid connection with an inlet to said filtration element, an inlet port for receiving retentate from said filtration element, and a retentate discharge port; and a single second piston slideably disposed within said single housing, said second piston positively sealing said inlet port when a feed pressure on a first face of said second piston exceeds a retentate pressure on a second face of said second piston; wherein pressure recovery is provided by a pressure difference between the feed chamber and the retentate chamber acting on said first piston. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method of filtering a substance comprising the steps of:
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pumping the substance with a first piston, wherein the first piston separates a feed chamber and a retentate chamber; passing the substance through at least one membrane filtration element, thereby separating the substance into permeate and retentate; and discharging the retentate using a differential pressure activated (DPA) valve, the DPA valve disposed downstream of the membrane filtration element and the retentate chamber with respect to a flow of the retentate, the DPA valve comprising; a single housing comprising a port in fluid connection with an inlet to said filtration element, an inlet port for receiving retentate from said filtration element, and a retentate discharge port; and a single second piston slideably disposed within said single housing, said second piston positively sealing said inlet port when a feed pressure on a first face of said second piston exceeds a retentate pressure on a second face of said second piston. - View Dependent Claims (26, 27, 28, 29, 30)
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Specification