JP2001099091A - Rotary (roto-dynamic) high-pressure machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a centrifugal compressor so as to obtain the high pressure SOLUTION: A device of this invention includes an impeller, which has vanes 5, 6 forming two pressure steps and directed in the radial direction and a circular disk 3 provided on each side surface. The vanes are respectively provided with cover disks 8, 9, and these cover disks are provided with vanes 4, 7 directed in the radial direction on each outward side surface so as to form other two pressure steps.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-pressure machine (hig)
h-pressure machine, i.e. a pump for liquids, or a compressor for achieving medium transfer under high pressure.

Although reference is made below to liquid pumps, the invention is also applicable to machines for transporting gaseous media.

[0003]

2. Description of the Prior Art Centrifugal pumps are preferred when pumping liquid to a high level, and thus to the point where high pressure is required. Such pumps include a pump impeller on a rotating shaft, the impeller being designed with a hub and a circular disc with one or more impeller vanes. Liquid enters the center in the axial direction and exits the impeller from the periphery. The pump housing surrounding the impeller is kinetic energy (kinetic)
C energy) into pressure energy that achieves transfer to higher levels.

[0004] At higher heads, it is common to use pumps with high rotational speeds and relatively small diameters. By coupling the outlet from the first step to the inlet to the second step, etc.
It is also possible to connect several pumps in series.
An example of connecting five steps in series is described in EP-A-35.
5781.

[0005] When a particular operating point at a particular rotational speed is selected, the use of multiple steps may be advantageous since the pump impeller can operate at a superior rotational speed in terms of efficiency. There is. This improvement in efficiency is mainly related to a reduction in frictional losses behind the impeller hub as part of the total losses. On the other hand, losses due to the connection between the steps are added. There is one further drawback, this relatively complex design means that maintenance and maintenance is complicated, and that longer shafts cause increased mechanical stress.

[0006] Another way to obtain a high pump head is to combine two identical pressure steps in series, as shown in US-A-958765 and DE-353698. In this case, the pump impeller is mirror-inverted (mirror-inverte).
d) It is arranged but otherwise has a conventional design. U.S. Pat. No. 2,136,939 discloses a pump with two pressure steps having a common hub disk and thereby achieving a reduction in disk loss. This solution, as well as the one described above, has in common that the principle only allows for two pressure steps and is not always enough to achieve the desired lift.

[0007]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a pump or compressor having more than two pressure steps with very high efficiency by minimizing disk losses. . The device according to the invention is also characterized in that its design is very small, easy to implement and can be adapted for axial forces and sealing pressures.

[0008]

Accordingly, a pump or compressor of the present invention is a pump or compressor of the centrifugal type providing high pressure, including a rotating shaft coupled to a motor and having an impeller surrounded by a housing. Wherein the impeller comprises a circular disc coupled to the hub, the disc comprising, on each side, a respective blade producing two pressure steps with an opposing portion of the housing, the edge of each of the blades comprising: A cover disk, the cover disks each having on its outwardly facing side additional blades forming two additional pressure steps with opposing portions of the housing, and further comprising a single or multiple flow passages Are respectively the outlet of the first pressure step and the second
Arranged between the inlets of the pressure steps, between the outlet of the second pressure step and the inlet of the third pressure step, or between the outlet of the third pressure step and the inlet of the fourth pressure step, An arrangement is provided in which the order of each other between these pressure steps is arbitrary.

The present invention is disclosed below with reference to the enclosed drawings.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, reference numeral 1 denotes a rotating shaft, and 2 denotes a pump impeller hub having a disk 3. 4, 5, 6 and 7 represent impeller blades, 8 and 9 represent cover discs and 10 represents a portion of the pump housing including walls 11 and 12 facing the impeller. 13, 14, 15, 16 and 17 represent seals and 18, 19, 20, 21 represent entrances to pressure steps. 22, 23, 24 and 25 represent diffusers during the pump steps. 2
6, 27 and 28 represent flow paths, 29 and 30 represent the inlet and outlet of the pump, respectively, and finally 31 represents the motor unit.

According to the invention, the high-pressure pump comprises a pump housing 10 in which the rotating hub 2 to which the disc 3 is connected is arranged. The disc 3 comprises vanes 5 and 6 on each side, respectively, and each vane group comprises a cover disc 8 and 9, respectively, and comprises a double-sided closed impeller.
a). The cover disks 8 and 9 are provided with additional vanes on their respective opposite sides, which together with the pump housing walls 11 and 12 form another double-sided pump impeller. In this way, two closed circuits (closed c
channel and two open chan
nel) is created.

This pump operates as follows. Liquid is drawn in via the inlet 29 and flows to the inlet 18 of the first pressure step. This step is formed by the blade 4, the cover disc 8 and the pump housing wall 11. A flow path 26 extends from the first pressure step diffuser 22 to the second pressure step inlet 19. The second step is formed by the blade 5, the lower surface of the hub disk 3, and the cover disk 8. A second flow path 27 continues from the second pressure step diffuser 23 to the third pressure step inlet 20. The third step includes the steps of: blade 6, upper surface of hub disk 3;
And the cover disk 9. The third flow path 28 is the diffuser 24 of the third pressure step.
To the inlet 21 of the fourth pressure step. The fourth
This step is formed by the blade 7, the cover disk 9, and the pump housing wall surface 12. Finally, the liquid exits the pump through the inlet 30 via the fourth pressure step diffuser 25.

The pump according to the invention offers several advantages over conventional high-pressure pumps having one or more pressure steps.

[0014] A plurality of pressure steps are more preferred for the specific rotation speed.
The efficiency is very high because d) occurs and the disk loss is greatly reduced.

The implementation of the pump is much simpler than the implementation of a conventional multi-stage pump. Furthermore, the trimming of this very small pump means that, due to its symmetrical design, axial forces as well as sealing pressure can be reduced.

The above-described embodiments of the present invention emphasize the importance of minimizing the pressure difference between two adjacent pressure steps. If it is more important to minimize the axial forces, it may be preferable to arrange the order between the steps differently. The scope of the present invention also includes embodiments in which all channels in the impeller are closed.

As described above, the present invention is not limited to a pump for liquids, but can be applied to pressurization of a gaseous medium.

Within the scope of the present invention, the outer vanes 4 and 7
It is also possible to increase the number of pressure steps by providing a cover disc on the cover. The disc may also include additional vanes that cooperate with additional pump housing walls or the like to create additional pressure steps.
The various pressure steps are connected via single or multiple channels.

[Brief description of the drawings]

FIG. 1 is an axial sectional view of a pump according to the present invention.

FIG. 2 shows a sectional view according to FIG. 1 inserted in the view of the submersible pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotating shaft 2 Pump impeller hub 4 Impeller blade 8 Cover disk 10 Pump housing 11 Pump housing wall surface 12 Pump housing wall surface 13 Seal 18 Inlet to pressure step 22 Diffuser 26 Flow path 29 Pump inlet 30 Pump outlet 31 Motor unit

Claims (5)

[Claims] A rotating shaft (1) coupled to a motor (31) and having an impeller surrounded by a housing (10).
A centrifugal pump or compressor providing high pressure, said impeller comprising a circular disc (3) coupled to a hub (2), said disc being provided on each side with a housing (10). ) With vanes (5) and (6), respectively, which produce two pressure steps with opposing parts of said vanes, the edges of said vanes (5) and (6) comprising cover discs (8) and (9), respectively. , The cover discs rest on their outwardly facing sides with the housing (1).
0) with additional vanes (4) and (7), respectively, forming two additional pressure steps with the opposing parts, and single or multiple channels (26), (27) and (2)
8) are respectively between the outlet (22) of the first pressure step and the inlet (19) of the second pressure step, the outlet (23) of the second pressure step and the inlet (20) of the third pressure step, respectively. ) And between the outlet (24) of the third pressure step and the inlet (21) of the fourth pressure step, wherein the order of the pressure steps with respect to each other is arbitrary. , Pump or compressor. 2. The pump or compressor according to claim 1, wherein the pressure steps are arranged in ascending order, with the last step being close to the motor (31). 3. It has an annular inlet,
The pump or the compressor according to claim 1. 4. Combined with said last pressure step,
The pump or compressor according to claim 1, wherein the pump or compressor has an outlet that is directed tangentially from a radial direction. 5. The vane (4) and (7) comprises a cover disk having on each outwardly facing side an additional blade forming an additional pressure step with an additional pump housing part. The pump or compressor according to claim 1, wherein