GB2186027A - Pump housing for self-priming circulating pumps - Google Patents

Abstract

The internal surface 3 of the pump housing 2 has a cylindrical surface 6 coaxial with the pump axis pump and is matched to a cylindrical surface of a closure element 7 on the suction side of the pump, there being a seal 8 disposed therebetween. The flange 20 of an opposite housing part has a lid 15 with the intervention of a seal 21, the pump shaft 16 being rotatably attached to the lid 15. Between the pump impeller and the side-wall of the housing as well as lid 15 there is a concentric liquid channel 22. The inlet and outlet port may be disposed on a common axis. <IMAGE>

Description

SPECIFICATION "In-line" pump house for self-priming circulating pumps The invention relates to the design of a pump house, by the aid of which sealing problems of self-priming circulating pumps, in particular multistage pumps can be solved, in addition "in-line" insertion ofthe pumps becomes possible.

As it is a well-known fact, efficiency of self-priming circulating pumps used to befarworsethan that of the turbine pumps, accordingly, it has been generally accepted that due to improper sealings leakage could be frequently observed.

As soon as the pumps are used for the delivery of liquids containing a gas, sealing becomes critical, with increasing number of stages number of sealing also increases. Recently, these pumps are used in ever increasing fields of the chemical industry and oil industry, where leakages result in sever contamination of the environment or toxic substance may be discharged into the atmosphere.

The aim ofthe invention was to reduce ali the problems connectedwith sealing tothe minimum.

It is also well known that when designing the "in-line" version ofthe turbine pumps, to facilitate building-in intothesystem,a pumphousewas developed, which surrounds the actual pump quasi as a second casing. We arrived at the recognition, in sofaras a pump house having been designed in this way may solve some problems not oniy in respect two the arrangement but to sealing problems, too.

Accordingly, our invention relates to a pump houseforself-priming circulating pumps, with which onthe inner side ofthe bottom partofthe pump house - having the shape of a pot - a cylindrical surface being coaxial with the shaft of the pump is formed, matching with the cylindrical surface ofthe closing element ofthe pump on the suction-side in a leak-proof manner, while the flange ofthe lateral wall of the pump house is matching to a releasably fixed lid in a leak-proofmannerandthe shaftofthe pump extends therethrough, while the pump is fixed exclusivelyto said lid; between the pump and the side-wall of the pump and the lid there is a concentric liquid channel, while the suction channel extends into the space of the bottom of the pump house being enclosed by the cylindrical surface and the pressure channel discharges into the sidewall; at last inlet stud and outlet stud are preferably uni-axially arranged.

As itcan be well seen, the pump house separates hermeticallythe pump from the surroundings, as a consequence, the pressure space encloses completelythe actual pump and eliminates in such a manner leakages at the pump sealing. The pump house according to the invention can be prepared with the traditional pump arrangement, too, the possibility of "in-line" insertion represents but a plus possibility.

The invention will be described in details by means of a preferred embodiment serving as example, by the aid of the drawings enclosed, wherein.

Figure 1 is the half-section/half-view of the self-priming multistagecirculating pump, Figure2the axial section ofthe pump house of the pump according to Figure 1, Figure 3 is the top view of the pump house.

As may be seen in Figure 1, a multi-stage self-priming circulating pump 1 according to the invention is built-up essentially of elements which form a pump 1 arranged in a pump housing 2 inthe following manner: The pump housing 2 is a pot-shaped casting. From a bottom part3 a guideflange 5 projects into an inner space 4. The guide flange 5 is arranged coaxiallywith the pump housing 2 and its outer cylindrical surface 6 is machined to an accuracy and quality required for use with hydraulic seals.

The cylindrical surface of an annular closing element7 on the suction-side ofthe pump 1 is pulled onto the cylindrical surface 6. A seal 8 is arranged between the guide flange 5 and the closing element7 on the suction-side.

A suction orifice 10 of the pump 1 communicates with a space 9 confined by the guide flange 5. The space 9 also receives the discharge of the suction channel 11 of the pump housing 2, the suction channel 11 being continued in an inlet coupling 13 provided with a connecting flange 12.

The pump 1 is fixed to a cover 15 with its own fastening screws 14. A shaft 1 6 of the pump 1 extends - properly sealed -through the lid 15 and it is coupled by means of a clutch 17tothe axisofan electric motor 18.

The lid 15 fixed to a flange 20 of the side-wall of the pump housing 2 by means of screws 19. Aseal 21 is arranged between the flange 20 and the lid 15. The way in which the pump 1 is fixed to the cover 15 and the selection ofthe magnitude of the inner diameter ofthe pump housing 2 in relation to the outer diameter ofthe pump 1 are such as to form a concentric continuous liquid channel 22 between the pump 1 and cover lid 15 and the sidewall ofthe pump housing 2, respectively.

The delivery or pressure orifice 23 ofthe pump 1 communicateswith the liquid channel 22; a delivery channel 24 passed through the side wall of the pump housing 2 also discharges into this channel 22 which ends in an outflow 25 surrounded by a connecting flange 26. As an 'in-line' design is most advantageous from the point of view of design and assembly as well, the inflow 13 and the outflow 25 are formed coaxially.

The complete equipment operates as follows: The pump1 -driven bythe motor 18-sucks inthe liquid to be delivered via the inflow 13, the suction channel 11, the space 9 and the suction orifice 10. By means ofthe seal 8 arranged between the guide flange 5 and the closing element on the suction side it can be assured thatthe suction side ofthe pump 1 is separated from the delivery side in a leak-proof manner.

The liquid leaves the pump 1 throughthedelivery orifice 23, arrives at the concentric liquid channel 22, from there into the delivery channel 24 and leaves the pump housing 2 through the oufflow 25.

As may be seen, between the structural elements enclosing the liquid channel 22 remaining under an overpressurethere are only two seals through which the medium delivered could be discharged into the atmosphere. Atthe same time, with a two-stage pump three seals are needed; with a three-stage pump one more.

Claims (4)

1. A pump housing for self-priming circulating pumps, wherein the housing has an essentially pot-shaped bottom the interior of which has a cylindrical surface coaxial with the axis ofthe pump matched to the cylindrical surface of a closing element ofthe pump on the suction sidewith the intervention ofthe seal, while a flange of the side wall ofthe pump housing is matched to a releasably fixed coverwith the intermediation ofafurtherseal and the axis ofthe pump extends therethroug and the pump is fixed exclusively to said cover; and wherein there is a concentric liquid channel between the pump and the sidewall ofthe pump housing as well as the cover and the suction channel discharges into a space of the bottom of the pump housing which is surrounded by the cylindrical surface, and the delivery channel is guided to the side wall.

2. Apump housing according to claim 1,wherein the inflow and the outflow are coaxially arranged.

3. A pump housing substantially as herein described with reference to and as shown in the accompanying drawings.

4. A pump including a pump housing as claimed in any preceding claim.