Pump having liquid blades and an associated method of pumping

Patent metadata

Field	Value
Publication number	US-11719244-B2
Application number	US-201816639528-A
Country	US
Kind code	B2
Filing date	Aug 16, 2018
Priority date	Aug 17, 2017
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

A pump and method for pumping a gas are disclosed. The pump comprises a rotor and a stator. At least one of the rotor or stator comprises at least one liquid opening configured for fluid communication with a liquid source. The liquid opening is configured such that in response to a driving force exerted on liquid from the liquid source a stream of liquid is output from the opening, the stream of liquid forming a liquid blade between the rotor and the stator, gas confined by said stator, said rotor and said liquid blade being driven through said pump from a gas inlet towards a gas outlet.

First claim

The invention claimed is:

1. A positive displacement vacuum pump for pumping a gas, the positive displacement vacuum pump comprising:
a gas inlet and a gas outlet;
a rotor and a stator, the stator defining a stator bore, wherein the rotor is located within the stator bore;
a shaft connected with the rotor and configured to rotate the rotor within the stator bore, wherein the stator bore surrounds the rotor and the shaft;
at least the rotor comprising at least one liquid opening configured for fluid communication with a liquid source a bottom portion of the rotor and the shaft each being at least partially immersed in the liquid source located in a liquid reservoir at the bottom of the stator bore; and
the at least one liquid opening being configured such that, in response to a driving force exerted on liquid from the liquid source, a stream of liquid is output from the at least one liquid opening, the stream of liquid forming a liquid blade between the rotor and the stator, within the stator bore,
wherein the gas is confined by the stator, the rotor, and the liquid blade and the liquid blade drives the gas through the positive displacement vacuum pump from the gas inlet towards the gas outlet,
wherein the shaft extends away from and above the liquid reservoir within the stator bore in a vertical direction, and
wherein a longitudinal axis of the shaft of the rotor and a longitudinal axis of the stator are orientated in the vertical direction.

2. The positive displacement vacuum pump according to claim 1 , wherein the stream of liquid forming the liquid blade between the rotor and the stator is operable to drive the gas through the positive displacement vacuum pump on rotation of the rotor.

3. The positive displacement vacuum pump according to claim 2 , further comprising at least one hydrodynamic bearing using a liquid film with liquid from the liquid source to support at least one end of the rotor.

4. The positive displacement vacuum pump according to claim 1 , further comprising a driving mechanism for exerting the driving force on the liquid to drive the liquid from the liquid source through the at least one liquid opening.

5. The positive displacement vacuum pump according to claim 4 , wherein the rotor is a hollow body and the driving mechanism comprises a motor for rotating the rotor and the shaft.

6. The positive displacement vacuum pump according to claim 5 , wherein the liquid source comprises water.

7. The positive displacement vacuum pump according to claim 5 , wherein the rotor has an intake opening at a lower end extending into the liquid reservoir, wherein an internal diameter of said hollow body is greater than an internal diameter of the intake opening.

8. The positive displacement vacuum pump according to claim 1 , wherein the at least one liquid opening is formed on a surface of the rotor.

9. The positive displacement vacuum pump according to claim 1 , wherein the rotor and the stator are mounted, such that the rotor comprises an inner component and the stator comprises an outer component, wherein the inner component is concentrically mounted within a bore of the outer component.

10. The positive displacement vacuum pump according to claim 1 , wherein the rotor is eccentrically mounted within the bore of the stator.

11. The positive displacement vacuum pump according to claim 1 , wherein the at least one liquid opening extends along at least a portion of a length of the rotor, the at least one liquid opening being configured to provide the liquid blade as a surface extending at least partially in an axial direction between the stator and the rotor.

12. The positive displacement vacuum pump according to claim 1 , wherein the at least one liquid opening is arranged in the form of a helix extending around a surface of the rotor, the at least one liquid opening being configured to provide the liquid blade as a helical surface between the stator and the rotor.

13. The positive displacement vacuum pump according to claim 12 , wherein an angle of the helix changes from the gas inlet towards the gas outlet such that a pitch of the helix reduces towards the gas outlet.

14. The positive displacement vacuum pump according to claim 1 , wherein the stator is tapered such that a distance between the stator and the rotor reduces from the gas inlet towards the gas outlet.

15. The positive displacement vacuum pump according to claim 1 , wherein the at least one liquid opening comprises a plurality of liquid openings.

16. The positive displacement vacuum pump according to claim 15 , wherein the plurality of liquid openings provide a plurality of streams of liquid which form a plurality of liquid blades between the rotor and the stator.

17. The positive displacement vacuum pump according to claim 16 , wherein the qas inlet and the qas outlet comprise a plurality of pairs of gas inlets and gas outlets, each pair of gas inlets and gas outlets of the plurality of pairs of qas inlets and qas outlets being separated by a corresponding liquid opening providing the liquid blade between each pair of gas inlets and gas outlets.

18. The positive displacement vacuum pump according to claim 1 , wherein, during operation of the positive displacement vacuum pump, the pump is configured so that the liquid blade, an external surface of the rotor, and an internal surface of the stator that defines the stator bore form surfaces of at least one pumping chamber for moving the gas from the gas inlet towards the gas outlet.

19. A wet scrubber for reducing pollutants pumped from an abatement system, the wet scrubber comprising the positive displacement vacuum pump according to claim 1 .

20. The positive displacement vacuum pump of claim 1 , wherein during operation of the pump a gas pocket is defined by the stator, the rotor, and the liquid blade and the rotation of the rotor causes a change in volume of the gas pocket.

21. A method of positive displacement pumping of a gas comprising:
outputting liquid from at least one liquid opening on a rotor to form a liquid blade between an external surface of the rotor and an internal surface of a stator,
wherein a shaft is connected to the rotor and configured to rotate the rotor within a bore of the stator,
wherein remaining liquid from the liquid blade flows back down the surface of the stator in a vertical direction into a liquid reservoir;
wherein the rotor extends away from and above the liquid reservoir within the stator bore in the vertical direction; and
wherein a longitudinal axis of the shaft of the rotor and a longitudinal axis of the stator are orientated in the same vertical direction; and

rotating the rotor and thereby causing gas confined by the stator, the rotor, and the liquid blade to travel along a pumping path from a gas inlet to a gas outlet.

22. The method according to claim 21 , wherein rotating the rotor further includes rotating the rotor within the stator bore to cause the liquid blade to drive the gas along the pumping path.

23. A positive displacement vacuum pump for pumping a gas, said pump comprising:
a rotor and a stator defining a stator bore, the rotor received within the stator bore; and
a shaft connected to the rotor and configured to eccentrically rotate the rotor within the stator bore,
the rotor comprising at least one liquid opening configured for fluid communication with a liquid source;
wherein the at least one liquid opening, in response to a driving force exerted on the liquid from the l

Assignees

• Edwards Ltd

Inventors

• Stones Ian David
• Schofield Nigel Paul
• Norton Ian Andrew

Classifications

• F04D17/18 Primary

  characterised by use of centrifugal force of liquids entrained in pumps {(, e.g. by means of an auxiliary liquid; fluid ring compressors F04C19/00)} · CPC title

• F04C25/02

  for producing high vacuum (sealing arrangements F04C27/00; silencing F04C29/06) · CPC title

• F04C29/0057

  for eccentric movement · CPC title

• F04C29/0092

  Removing solid or liquid contaminants from the gas under pumping, e.g. by filtering or deposition; Purging; Scrubbing; Cleaning · CPC title

• F04C29/124

  with inlet and outlet valves specially adapted for rotary or oscillating piston pumps · CPC title