Liquid purification or separation – Recirculation – Serially connected distinct treating or storage units
Reexamination Certificate
2000-07-06
2001-10-09
Drodge, Joseph W. (Department: 1723)
Liquid purification or separation
Recirculation
Serially connected distinct treating or storage units
C210S090000, C210S137000, C210S253000, C210S321660, C210S416300, C417S313000, C417S404000, C417S216000
Reexamination Certificate
active
06299766
ABSTRACT:
TECHNICAL FIELD
This invention relates to apparatus for providing a flow of pressurized liquid and passing the pressurized liquid through a plurality of reverse osmosis filters to separate the pressurized liquid into a permeate portion and a concentrate portion. The apparatus is particularly useful for desalinization of seawater.
BACKGROUND OF THE INVENTION
My U.S. Pat. No. 5,482,441, issued Jan. 9, 1996, discloses a system which can be utilized to desalinate seawater. The system includes a rotary variable displacement liquid pump and rotary metering device driven by a drive motor to pump liquid through containment structure and a single reverse osmosis filter.
My U.S. Pat. No. 5,462,414, issued Oct. 31, 1995 and U.S. Pat. No. 5,628,198, issued May 13, 1997, disclose other approaches to solving certain problems inherent in the prior art and have features in common, including the use of a reversible piston which cooperates with filter means to produce desalinated water.
U.S. Pat. No. 4,793,153, issued Dec. 27, 1998, discloses a prior art hydraulic circuit employing a reversible piston to accomplish “energy recovery” in a mixed-phase motor in a refrigeration system.
U.S. Pat. No. 4,367,140, issued Jan. 4, 1983, discloses apparatus for the reverse osmosis purification of water or other fluid wherein the water is forced into a module containing a membrane under pressure using two piston-cylinder assemblies mechanically inter-connected.
U.S. Pat. No. 6,017,200, issued Jan. 25, 2000, discloses an energy-recovery pump or pumping system which includes, in a double-action embodiment, first and second cylinders wherein respective first and second pistons, mounted to a common reciprocal reciprocating piston shaft, are mounted for reciprocating motion.
It is known to pump sea water or other liquid seriatim through a series of reverse osmosis filters, however, such arrangements are inefficient in that downstream filters tend to clog and operate with less efficiency since they receive essentially undiluted concentrate from upstream filters. This results in high operating costs and inefficiencies in the system.
DISCLOSURE OF INVENTION
The apparatus of the present invention, in common with some of the prior art patents noted above, is for the purpose of filtering liquid, such as sea water when the liquid is pressurized. However, the present invention is characterized by its ability to provide highly effective filtering with the expenditure of considerably less energy than the systems known in the prior art. As will be seen in greater detail below, the apparatus of this invention employs a plurality of reverse osmosis filters in a highly effective manner, as compared to prior art approaches using a plurality of reverse osmosis filters wherein each subsequent filter results in less recovery than filters upstream. Concentrate can be recirculated for refiltering without fouling the filters.
Each of the plurality of reverse osmosis filters employed in the liquid filtering apparatus of the present invention has an inlet, a permeate exit outlet and a concentrate exit outlet.
Liquid flow path defining means is connected to a liquid pump of the apparatus for receiving liquid under pressure and delivering the liquid under pressure separately to each of the reverse osmosis filters. The liquid flow path defining means inter-connects the reverse osmosis filters and provides liquid flow communication between the inlet of at least one of the reverse osmosis filters and the concentrate exit outlet of another of the reverse osmosis filters.
Liquid recirculation means is operatively associated with the plurality of reverse osmosis filters and with the liquid flow path defining means for recirculating under pressure liquid including concentrate produced by the reverse osmosis filters through the reverse osmosis filters seriatim.
The liquid recirculation means includes recirculation conduit means connected to an outlet of one of the reverse osmosis filters and to the concentrate exit outlet of another of the reverse osmosis filters as well as recirculation pump means for pumping liquid including concentrate through a liquid flow path loop at least partially defined by the reverse osmosis filters and the recirculation conduit means.
Other features, advantages, and objects of the present invention will become apparent with reference to the following description and accompanying drawings.
REFERENCES:
patent: 4342651 (1982-08-01), Ahrens
patent: 4367140 (1983-01-01), Wilson
patent: 4793153 (1988-12-01), Hembree et al.
patent: 5204001 (1993-04-01), Tonelli et al.
patent: 5306428 (1994-04-01), Tonner
patent: 5462414 (1995-10-01), Permar
patent: 5482441 (1996-01-01), Permar
patent: 5628198 (1997-05-01), Permar
patent: 5647973 (1997-07-01), Desaulniers
patent: 6017200 (2000-01-01), Childs et al.
patent: 6139740 (2000-10-01), Oklejas
Cecil Terry K.
Drodge Joseph W.
Lange Thomas R.
LandOfFree
Reverse osmosis filtering apparatus with concentrate dilution does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Reverse osmosis filtering apparatus with concentrate dilution, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Reverse osmosis filtering apparatus with concentrate dilution will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2586949