AU5941800A

AU5941800A - A roto-dynamic high-pressure machine

Info

Publication number: AU5941800A
Application number: AU59418/00A
Authority: AU
Inventors: Ulf Arbeus
Original assignee: ITT Manufacturing Enterprises LLC
Current assignee: ITT Manufacturing Enterprises LLC
Priority date: 1999-09-15
Filing date: 2000-09-13
Publication date: 2001-03-22
Anticipated expiration: 2020-09-13
Also published as: AR026878A1; DE60026490T2; SE9903278L; BR0004211A; EP1085212B1; AU762289B2; CA2319607A1; EP1085212A3; CA2319607C; MXPA00008931A; SE521399C2; JP2001099091A; DE60026490D1; EP1085212A2; SE9903278D0; ZA200004443B; ATE319934T1

Description

S&F Ref: 521873

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant Actual Inventor(s): Address for Service: Invention Title: ITT Manufacturing Enterprises, Inc.

1105 North Market Street Wilmington Delaware 19801 United States of America Ulf Arbeus Spruson Ferguson St Martins Tower 31 Market Street Sydney NSW 2000 A Roto-dynamic High-pressure Machine The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845c

I

A ROTO-DYNAMIC HIGH-PRESSURE

MACHINE

Technical Field The invention concerns a high-pressure machine, and in particular a pump for liquids or a compressor for pressurising a gaseous media.

Background of the Invention When pumping liquids, for example, to high levels a high pressure is needed and a pump of the centrifugal type is preferred. Such a pump generally comprises a pump impeller on a rotating shaft, said impeller being designed with a hub and a circular disc provided with one or several impeller vanes. The liquid enters in an axial direction in the center and leaves the impeller at the periphery. A pump housing surrounding the impeller, transforms the kinetic energy to pressure energy which drives the liquid to a higher level.

At higher heads it is common to use pumps with high rotation speeds and relatively small diameters. It is also possible to connect a number of pumps in series by connecting the outlet from a first step of the inlet to a second step and so on. An example is shown in EP-A-3 55781, where five steps are connected in series.

0 V When a certain operation point at a certain rotation speed is chosen, it can be an advantage to use several steps, as the pump impellers can operate at rotation speeds which are superior with regard to efficiency. This increase of efficiency is mainly related to the fact that the friction losses at the back sides of the impeller hubs, as a part of the total losses, decrease. On the other hand the linking losses between the steps are added. One disadvantage is, that the relatively complicated design means that service and maintenance become complicated and in addition long shafts bring about increased mechanical stress.

Another way to obtain high pump heads is to connect two identical pressure steps in series as is shown in US-A-958 765 and DE-353 698. The pump impellers are here been arranged mirror-inverted, but have in other respects conventional designs.

US-A-2 136 939 for example discloses a pump with two pressure steps having a common hub disc, thereby obtaining a reduction of the disc losses. This solution, as well as the one previously mentioned, have in common that the principle only allows two pressure steps, which is not always sufficient for obtaining the desired pump head.

I R LIBLL] 10036.doc:KEH Object of the Invention It is an object of the present invention to overcome or ameliorate some of the disadvantages of the prior art, or at least to provide a useful alternative.

Summary of the Invention s There is firstly disclosed herein a pump or compressor of a centrifugal type for providing high pressures, comprising a rotary shaft connected to a motor and provided with an impeller surrounded by a housing, wherein: the impeller comprises a circular disc connected to a hub, said disc being provided on each side with vanes, which together with opposing parts of the housing 1o create two pressure steps, the edges of said vanes respectively are provided with cover discs, which on their outwardly directed sides are provided with additional vanes, which together with opposing parts of the housing form two additional pressure steps, and wherein single or multiple flow conduits are arranged respectively between the outlet of a first pressure step and the inlet of a second pressure step, between the outlet of said second pressure step and the inlet of a third pressure step and between the outlet of said third pressure step and the inlet of a fourth pressure step, the mutual order between said pressure steps being arbitrary.

The present invention, at least in a preferred embodiment, provides a pump or a 20 compressor including more than two pressure steps having a very high efficiency thanks to the fact that the disc losses are minimized, the design is very compact, easy to mount and adaptable with regard to axial force and seal pressure.

Brief Description of the Drawings A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings.

Fig. 1 shows an axial cut through section of a pump according to an embodiment of the invention; Fig. 2 shows the cut through section according to Fig. 1 inserted in a view over a submersible pump.

Detailed Description of the Preferred Embodiment In the drawings there is disclosed a rotary shaft 1, a pump impeller hub 2 having a disc 3. Impeller vanes 4, 5, 6 and 7, cover discs 8 and 9 and a part of a pump housing [R:\LIBLL] 10036.doc:KEH 3 comprise walls 1 and 12 opposing the impeller. 13, 14, 15, 16 and 17 symbolise seals, 18, 19, 20 and 21 stand for inlets to the pressure steps. 22, 23, 24 and 25 stand for diffusors in the pump steps. 26, 27 and 28 stand for flow conduits, 29 and 30 inlet and outlet respectively for the pump and 31 finally, a motor unit.

s According to the invention the high-pressure pump comprises a pump housing within which a rotating hub 2 with a connected disc 3 is arranged. The disc 3 is on each side provided with vanes 5 and 6 respectively, each group of vanes being provided with a cover disc 8 and 9 respectively and creating a double-sided closed pump impeller.

The cover discs 8 and 9 are on their respective opposite sides provided with additional to0 vanes which form another double sided pump impeller together with the pump housing walls 11 and 12 respectively. In this way a four-step pump impeller is created having two closed and two open channels.

The pump operates in the following way: the liquid is sucked in through the inlet .0 029 and flows to the inlet 18 of the first pressure step. This step is formed by the vanes 4, I s the cover disc 8 and the pump housing wall 11. A flow conduit 26 goes from the diffusor 22 of said first pressure step to the inlet 19 of a second pressure step, said second step 0 being formed by the vanes 5, the underside of the hub disc 3 and the cover disc 8. A second flow conduit 27 goes form the diffusor 23 of said second pressure steps to the inlet 20 of a third pressure step, said third step being formed by the vanes 6, the upside of the hub disc 3 and the cover disc 9. A third flow conduit 28 goes form the diffusor 24 of said third pressure step to the inlet 21 of a fourth pressure step, said fourth step being formed °by the vanes 7, the cover disc 9 and the pump housing wall 12. Finally the liquid leaves the pump via the diffusor 25 of the fourth pressure step through the inlet The pump according to at least a preferred embodiment of the invention provides a number of advantages when compared with conventional high-pressure pumps having one or several pressure steps.

The efficiency is very high thanks to the fact that several pressure steps bring about a more favourable specific rotation speed and that the disc losses are reduced considerably.

The mounting of the pump is much simpler in a comparison with mounting of conventional multi-step pumps. In addition, trimming of the very compact pump means possibilities to reduce axial forces as well as seal pressure thanks to the symmetrical design.

\LIBLLJ 10036.doc:KEH 4 In the preferred embodiment of the invention that is described above, the importance of minimising the pressure difference between two adjacent pressure steps has been stressed. If it is more important to minimise the axial forces, another order between the steps might be preferred. The invention can also include an embodiment where all channels in the impeller are closed.

As previously mentioned, the invention is not limited to pumps for liquids, but is also possible to apply for pressurising of gaseous media.

Within the scope of the invention there is also a possibility to increase the number of pressure steps by providing the outer vanes 4 and 7 with cover discs. Said 10 discs may in their turn be provided with additional vanes which form additional pressure steps in cooperation with additional pump housing walls and so on, the different pressure steps being connected via single or multiple flow conduits.

[R:\LIBLL] 0036.doc:KEH

Claims

1. A pump or compressor of a centrifugal type for providing high pressures, comprising a rotary shaft connected to a motor and provided with an impeller surrounded by a housing, wherein: the impeller comprises a circular disc connected to a hub, said disc being provided on each side with vanes, which together with opposing parts of the housing create two pressure steps, the edges of said vanes respectively are provided with cover discs, which on their outwardly directed sides are provided with additional vanes, which together with o opposing parts of the housing form two additional pressure steps, and wherein single or multiple flow conduits are arranged respectively between the outlet of a first pressure step and the inlet of a second pressure step, between the outlet of said second pressure step and the inlet of a third pressure step and between the outlet of said third pressure step and the inlet of a fourth pressure step, the mutual order between said pressure steps being arbitrary.

2. The pump or compressor according to claim 1, wherein the pressure r •steps are arranged in an ascending order with the last step adjacent the motor.

3. The pump or compressor according to claim 1 or claim 2, further including a ring-formed inlet.

4. The pump or compressor according to any one of claims 1 to 3, further including a radially to tangentially directed outlet connected to the last pressure step.

5. The pump or compressor according to claim 1, wherein the vanes are provided with cover discs having on their respective outwardly directed sides additional vanes which form additional pressure steps together with additional pump housing parts.

6. The pump or compressor of a centrifugal type for providing high pressures, substantially as herein described with reference to any one of the embodiments of the invention shown in the accompanying drawings. Dated 12 September, 2000 ITT Manufacturing Enterprises, Inc. Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON IR:\LIBLL 10036.doc:KEH