Pumping apparatus

• US 4,756,830 A
• Filed: 05/18/1987
• Issued: 07/12/1988
• Est. Priority Date: 05/18/1987
• Status: Expired due to Term

• Current Assignee: Edward Fredkin
• Original Assignee: Edward Fredkin
• Inventors: Fredkin, Edward
• Primary Examiner(s): SPEAR JR, FRANK
• Application Number:
  US07/050,780
• Time in Patent Office: 421 Days
• Field of Search: 210/416.1, 210/321.66
• US Class Current: 210/321.66
• CPC Class Codes: B01D 61/06 Energy recovery

Abstract

The pumping apparatus disclosed herein recovers pumping energy required in feeding solution to a reverse osmosis unit. The reverse osmosis unit generates a purified product but also a concentrate stream which is discharged at a pressure only slightly lower than the feed pressure. The discharge flow is utilized to displace hydraulic fluid in a work exchange vessel and this displaced fluid is then boosted in pressure and supplemented by an additional flow of hydraulic fluid, the combined hydraulic fluid flow being then utilized to pressurize, through another work exchange vessel, the solution feed flow to the reverse osmosis unit.

Claims

1. Pumping apparatus for feeding a reverse osmosis unit, said apparatus comprising:

a plurality of work exchange subsystems each of which includes first and second work exchange vessels, the first said vessels receiving solution on one side and hydraulic fluid on the other, the second said vessels receiving concentrate on one side and hydraulic fluid on the other;

interconnection means, including a selectively operable valve, for permitting hydraulic fluid displaced by the introduction of solution into the one side of the respective first vessel to flow into the other side of the respective second vessel thereby displacing concentrate;

booster pump means for transferring hydraulic fluid to the other side of a selected one of said first vessels from the other side of the respective second vessel;

pump means for introducing additional hydraulic fluid into the other side of the selected first vessel;

means for selectively connecting the one side of each of the first said work exchange vessels to the solution inlet of a reverse osmosis unit;

means for selectively connecting the concentrate outlet of a reverse osmosis unit to said on side of a selected one of said second vessels so that hydraulic fluid thereby displaced aids said pumps in driving solution from the one side of the respective first vessel into the reverse osmosis unit.

2. Pumping apparatus for feeding solution at high pressure to a reverse osmosis unit, said apparatus comprising:

a pair of work exchange subsystems each of which operate alternatingly in high pressure phases, each of said subsystems including first and second work exchange vessels, the first said vessels receiving solution on one side and hydraulic fluid on the other, the second said vessels receiving concentrate on one side and hydraulic fluid on the other;

interconnection means, including a selectively operable valve, for permitting hydraulic fluid displaced by the introduction of solution into the one side of the respective first vessel to flow into the other side of the respective second vessel thereby displacing concentrate during a low pressure phase of operation of the respective work exchange subsystem;

booster pump means for transferring hydraulic fluid to the other side of a selected one of said first vessels from the other side of the respective second vessel during a high pressure phase of operation of the respective work exchange subsystem, the amount of hydraulic fluid transferred being substantially equal to the concentrate produced by the reverse osmosis unit;

pump means for introducing additional hydraulic fluid into the other side of a selected first vessel also during the respective high pressure phase of operation, the amount being substantially equal to the product produced by the reverse osmosis unit;

means for selectively connecting said one side of each of the first said work exchange vessels to the solution inlet of a reverse osmosis unit;

means for selectively connecting the concentrate outlet of a reverse osmosis unit to said one side of a selected one of said second vessels so that hydraulic fluid thereby displaced aids said pumps in driving solution from the one side of the respective first vessel into the reverse osmosis unit.