Method of converting liquid ring pumps having sealing liquid vents

Abstract

A conical member for a pump head of a liquid ring pump, the conical member including a body, the body defining a first body opening on a first end positioned to abut a first pump opening, a second body opening on the first end positioned to abut a second pump opening, and a port. The conical member further includes a radially outer lip arranged about the first end and positioned to abut a pump aperture. A sealing liquid introduction path is arranged to introduce sealing liquid to a working chamber, the sealing liquid introduction path arranged at least partially between the second body opening and an outlet, and a gas vent passage is arranged to vent gas from the working chamber, the gas vent passage arranged at least partially between the port and the first body opening.

Claims

1. A liquid ring pump comprising: a pump head arranged to operate using liquid venting, the pump head defining a first aperture, a first body opening, a second body opening, a sealing liquid vent aperture, a second aperture, and a main discharge to be coupled with a discharge piping system; and a gas venting conical member coupled to the pump head to provide gas venting, the gas venting conical member including a central aperture arranged to introduce sealing liquid into the pump and a cone port arranged to direct venting gas into the gas venting conical member; and piping disposed external to the pump head, downstream of the first aperture, and upstream of the discharge piping system, wherein the venting gas then flows through the first body opening and then the first aperture before exiting the pump head through the piping and either re-entering the pump head from the piping or entering the discharge piping system from the piping, and wherein sealing liquid enters the pump by first flowing through the second aperture and then through the second body opening before entering the gas venting conical member and passing through the central aperture.

2. The liquid ring pump of claim 1, wherein the pump head includes a radial lip sized to receive a flange formed as part of the conical member.

3. The liquid ring pump of claim 1, wherein the conical member defines a first end arranged to abut the pump head, a second end spaced apart from the first end, and a conical wall extending between the first end and the second end, and wherein the cone passage is formed in the conical wall between the first end and the second end.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a vertical sectional view of a prior art liquid ring pump taken along a plane parallel to the shaft of the pump.

(2) FIG. 1a is an end view of a pump head of the type shown in FIG. 1.

(3) FIG. 2 is a rough schematic of a blown up portion of the pump shown in FIG. 1 showing a sealing liquid vent path which allows discharge of sealing liquid around the rotor periphery.

(4) FIG. 3 is a stripped down horizontal sectional view of a pump of the type shown in FIG. 1 taken along a plane parallel to the pumps shaft; the Figure includes a pump head interfaced with a conical member.

(5) FIG. 4 is a horizontal sectional view through a liquid ring pump taken in a manner similar to the section of FIG. 3; the pump head and cone have been reconfigured in accordance with the present invention to allow gas to be vented in a channel previously used for sealing liquid introduction.

(6) FIG. 5 is an isometric view of the conical member shown in FIG. 3.

(7) FIG. 6 is an end view of the conical member shown in FIG. 5 looking into the nose or small end of the cone.

(8) FIG. 7 is an isometric view of the cone shown in FIG. 4.

(9) FIG. 8 is an end view of the cone shown in FIG. 7 looking into the nose or small end of the cone.

(10) FIG. 9 is an end view of a pump head of the type shown in FIG. 3.

(11) FIG. 10 is an end view of a reconfigured pump head of the type shown in FIG. 4.

DETAILED DESCRIPTION

(12) The present invention converts a pump, which relies on sealing liquid vent paths, also known as liquid leakage paths, into a pump which utilizes a gas vent path. The gas vent path is now used to accommodate varying compression ratios, instead of the sealing liquid vent path. Prior to conversion of the pump, the pump can have all of the features shown in FIGS. 1, 2 and 3. Prior to conversion, FIG. 3 shows a pump head 40 which has a sealing liquid (compressant) vent passage. The vent path or passage is formed by a channel 41a extending through pump head 40 and an aperture 41b extending through a flange 44 of conical member 46. The vent path allows unwanted sealing liquid 29 to exit the working chamber.

(13) Prior to conversion, the pump head 40 also has a sealing liquid introduction passage. The seal liquid introduction passage is formed by a channel passage 48a extending through pump head 40 and a channel 48b extending through conical member 46.

(14) To convert the pump shown in FIGS. 1 and 3 to a gas vented liquid ring pump, a new conical member 50, as shown in FIGS. 4, 7, 8 is provided. Additionally, the pump head 40 is reconfigured by possible machining and the like, such that the seal liquid introduction channel 48a is retasked to form a portion 448a of a gas vent passage. The new cone 50 forms another portion 448b of the gas vent passage. The cone passage 448b has a port 448b through which gas to be vented enters the cone passage 448b. As shown in FIG. 10, the gas vent passage could also include piping 55 to allow gas exiting the retasked pump head 440, through passage 448a, to terminate at the pump discharge 56 or to terminate in a discharge piping system 58. Accordingly, the gas vent is formed by cone port 448b, cone gas channel 448b, head gas passage 448a and the piping 55. As can be seen the pump in FIG. 10 has a main discharge 73.

(15) In providing a gas vent channel through a portion of the pump head 40 which was previously used as a portion of a sealing liquid introduction path, it is important to make sure the passageway provided has sufficient area for the release of gas from the working chamber. The smaller the passage, the greater the pressure required at the gas port 448b and the greater the power required by the vacuum pump to achieve that pressure at port 448b. The higher power represents increased operating cost to the end user. Tests have shown that a ratio of pump capacity to passage area of 490 to 1,160 CFM per square inch results in an adequate passage cross sectional area. Preferably, no portion of the passage should have a restricted area outside of the desired ratio range.

(16) As best seen in FIG. 8, for a cone 50 designed for operation at 20 inches of mercury vacuum that includes a single vent opening 448b, the leading edge 448b of the opening in the cone should occur between 130 and 140 angular degrees before the point of closest approach of the rotor blade 25a to rotor body 23. The point of closest approach of the rotor body is approximated by line 60. The direction of rotation is shown by arrow 61. The angle of the closing edge 448b of the vent opening (port) 448b is preferably from 110 to 115 angular degrees before the closest approach of the rotor to the body. The included angle from the closing of the vent opening to the opening of the cone's final discharge port 70 is approximately the angular distance between two successive rotor blades to a tolerance of 7 angular degrees. The inlet port is shown at 71.

(17) The new cone 50 is provided with a sealing liquid channel 441b which allows for sealing liquid 29 to now enter the working chamber through what was previously used as a compressant vent channel 41a. A portion of the compressant vent channel 41a is thus retasked to be a sealing liquid introduction path 441a. Also pump 40 is reconfigured so that the compressant vent passage 41a is partially sealed at 41a. Cone 50 seals the portion 41a of vent passage 41a by providing a cone flange 444 that omits vent port 41b. The flange 444 thus seals vent portion 41a at 41a. The path now retasked as the sealing liquid introduction path 441a, would be repiped as shown in FIGS. 9 and 10.

(18) The term gas used herein is broad enough to include air.

(19) Although an example of the invention has been disclosed, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the spirit and scope of the invention.

(20) All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

(21) Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

(22) The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.