Barrel-Type Pump with Venting Device and Associated Method

Abstract

A centrifugal pump with a barrel casing and a ventilation arrangement is provided. A plug-in unit is arranged in the barrel casing. The plug-in unit has a shaft, and at least one impeller is arranged on the shaft. The impeller is enclosed by a stage casing. The stage casing separates an inner pressure space from an outer pressure space. At least one venting device is arranged in the stage casing.

Claims

1-14. (canceled)

15. A centrifugal pump, comprising: a barrel casing; at least one stage casing located within the barrel casing between an inner pressure space radially inside the at least one stage casing and an outer pressure space between the at least one stage casing and the barrel casing; and at least one venting device arranged in the at least one stage casing arranged to control flow of a media between the inner pressure space and the outer pressure space.

16. The centrifugal pump as claimed in claim 15, wherein each of the at least one venting devices is arranged in a corresponding opening in the at least one stage casing, each opening being arranged to connect the inner pressure space to the outer pressure space.

17. The centrifugal pump as claimed in claim 16, wherein each of the at least one venting devices includes a corresponding flow control element configured to cooperate with the corresponding opening to enable or block flow of the media between the inner pressure space and the outer pressure space.

18. The centrifugal pump as claimed in claim 17, wherein the flow control element is arranged in a guide.

19. The centrifugal pump as claimed in claim 18, wherein the guide is a receptacle in the at least one stage casing configured to receive the flow control element.

20. The centrifugal pump as claimed in claim 19, wherein the opening located on a radially inward side of the receptacle.

21. The centrifugal pump as claimed in claim 20, wherein a free cross section for media exchange is present between a wall of the receptacle and the flow control element.

22. The centrifugal pump as claimed in claim 21, wherein the receptacle is a receptacle bore in the at least one stage casing.

23. The centrifugal pump as claimed in claim 22, wherein the opening is an opening bore into the at least one stage casing.

24. The centrifugal pump as claimed in claim 23, wherein a surface of the flow control element arranged is larger a diameter of the opening, such that when the flow control element is in a flow blocking position media flow through the opening is blocked.

25. The centrifugal pump as claimed in claim 24, wherein the flow control element is a disk.

26. The centrifugal pump as claimed in claim 24, wherein the venting device includes a stop arranged to prevent movement of the flow control element out of the receptacle bore.

27. The centrifugal pump as claimed in claim 15, wherein the venting device is arranged in an upper region of the at least one stage casing. preferably in a 12 o'clock position.

28. The centrifugal pump as claimed in claim 27, wherein the venting device is located at a highest location at which gas accumulates.

29. A method for performing a pressure test in a centrifugal pump as claimed in claim 1 at a location at which the pump is installed, comprising the steps of: priming the centrifugal pump with the media; maintaining the flow control element in a flow-enabled position while gas is purged from the inner pressure space to the outer pressure space; and maintaining the flow control element in a flow-blocked position after the gas is purged from the inner pressure space to the outer pressure space.

30. The method for performing a pressure test as claimed in claim 29, wherein after the media in the inner pressure space enters the at least one venting device, the flow control element shifts between the flow-enabled position and the flow-blocked position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 shows an axial section through a barrel-type pump in accordance with the present invention,

[0025] FIG. 2 shows a schematic illustration of the venting device in accordance with the present invention.

DETAILED DESCRIPTION

[0026] FIG. 1 shows a centrifugal pump having a barrel casing 1. A plug-in unit 2 is arranged in the barrel casing 1. The plug-in unit 2 comprises a shaft 3, on which a plurality of impellers 4 is arranged in series. In the illustrative embodiment, the impellers 4 are radial impellers.

[0027] Each impeller 4 is enclosed by a stage casing 5. Adjacent stage casings 5 adjoin one another. The joint between the stage casings 5 forms a metal seal in the illustrative embodiment.

[0028] Formed integrally on the barrel casing 1 is an intake connection 6, through which the operating medium enters the centrifugal pump. The operating medium leaves the centrifugal pump via a discharge connection 7.

[0029] According to the invention, a venting device 8 is arranged in an upper region in the pressure casings 5, in each case in a 12 o′clock position. The barrel-type pump according to the invention can thus be subjected to a pressure test in the fully assembled state. This is only made possible by the integration of the venting devices 8. The venting devices 8 ensure that the barrel-type pumps that are already fully installed in the plant can be primed and that, in the process, air can escape via the venting devices 8.

[0030] FIG. 2 shows a schematic illustration of a venting device 8. The venting device 8 is integrated into each stage casing 5. The stage casing 5 separates an inner pressure space 9 from an outer pressure space 10. The inner pressure space 9 is arranged around the impellers 4. The outer pressure space 10 is situated between the stage casing 5 and the barrel casing 1 and is connected in terms of pressure to the interior of the discharge connection 7.

[0031] According to the invention, the venting device 8 comprises an opening 11, which is introduced as a bore into the stage casing 5. The venting device 8 furthermore comprises a receptacle 12. The receptacle 12 is a depression which, in the illustrative embodiment, is introduced as a circular recess in the form of a bore into the outer circumferential surface of the stage casing 5. It forms a region of the opening 11 of enlarged inside diameter. Arranged in the receptacle 12 is an element 13. In the illustrative embodiment, the element 13 is a disk-type element, which is of cylindrical design. The diameter of the element 13 is smaller than the diameter of the receptacle 12, and therefore the element 13 is arranged in the receptacle 12 in such a way as to be movable in the radial direction.

[0032] In the variant illustrated in FIG. 2, the venting device 8 comprises a stop 14, which prevents the element 13 from being carried out of the receptacle 12. The stop 14 can comprise projections which protrude into the receptacle 12 or a snap ring inserted into an annular groove provided in the receptacle 12.

[0033] If the barrel-type pump is primed with operating medium for pressure testing, the element 13 is pushed upward or outward in a radial direction and opens a free cross section for the escape of the air. The stop 14 acts as a safety element and prevents the element 13 from being carried out of the receptacle 12, e.g. by vibration during operation or by the air flow during venting. During the priming process, the rising operating medium in the inner pressure space 9 raises the element 13 by means of the hydrostatic water column until all the air has escaped. The fully vented system is then put into operation. During operation, a higher operating pressure is established in the outer pressure space 10 than in the inner pressure space 9. Owing to this pressure difference, the element is pressed against the bottom of the receptacle 12 in the stage casing 5. The element 13 is embodied as a sealing element and prevents operating medium from flowing back from the outer pressure space 10 into the inner pressure space 9. For this purpose, the contact surfaces between the bottom of the receptacle 12 and the element 13 are embodied in such a way that reliable sealing is ensured.

[0034] The venting device according to the invention manages completely without spring elements. By dispensing with spring elements, the venting device according to the invention proves to be free from wear and requires little maintenance. It is distinguished by reliable operation and a long service life. Moreover, no further energy source is required apart from the operating medium. Thus, the venting device according to the invention is independent of external energy sources and does not additionally increase operating costs.

[0035] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.