CN204267300U - Centrifugal pump - Google Patents

Abstract

The embodiment of the utility model discloses a centrifugal pump, which comprises: a pump body, a flange pipe and an ejection device, and the ejection device is respectively connected to the pump body and the flange pipe; the pump body is provided with Pump body inlet pipe and diffuser pipe, one end of the diffuser pipe communicates with the pump body, the other end is provided with a pump outlet, and the flange pipe is provided with a pump inlet; the injection device includes a drainage pipe and an incident pipe , wherein, one end of the drainage pipeline communicates with the diffuser tube, and the other end communicates with the incident pipeline; one end of the incident pipeline communicates with the pump body inlet pipe, and the other end communicates with the flange tube, and the incident The pipelines are flexibly connected with the inlet pipe of the pump body and the flange pipe respectively. The injection device of the centrifugal pump in the embodiment of the present application is flexibly connected with the inlet pipe of the pump body and the flange pipe, and the distance between the fluid ejected by the injection device and the inlet of the impeller can be freely adjusted, thereby effectively avoiding the occurrence of cavitation and improving the centrifugal pump. Anti-cavitation performance of the pump.

Description

centrifugal pump

technical field

The utility model relates to the technical field of liquid conveying power equipment, in particular to a centrifugal pump capable of improving anti-cavitation performance.

Background technique

At present, in order to meet various conveying requirements, pump products are gradually developing towards high speed. As we all know, when the speed of the pump impeller is increased, the pressure at the impeller inlet will drop rapidly while the outlet pressure of the impeller rises rapidly, which makes cavitation more likely to occur (cavitation means that when the local pressure in the liquid decreases, the liquid inside the liquid or on the liquid-solid interface The process of the formation, development and collapse of steam or gas cavitation, cavitation will easily cause the efficiency of centrifugal pumps to decrease, the material of the pump body will be eroded, and vibration and noise will be generated), which will make the anti-cavitation performance of the pump body continue to deteriorate .

In the prior art, the usual way to improve the anti-cavitation performance of the centrifugal pump is to install an ejector device at the outlet of the centrifugal pump, through which the high-pressure fluid at the outlet of the pump is diverted to the inlet of the impeller, and the high-pressure fluid The low-pressure fluid is supplemented with energy, so that the fluid pressure at the inlet of the impeller rises to avoid the occurrence of cavitation.

However, the length of the axial pipeline from the injection hole to the inlet of the impeller in the injection device of the existing centrifugal pump is relatively fixed and cannot be adjusted freely, resulting in a small change in the pressure compensation of the high-pressure fluid entering the inlet of the impeller to the low-pressure fluid. When it is necessary to increase the impeller speed of the centrifugal pump, the pressure compensation of the high-pressure fluid to the low-pressure fluid cannot be adjusted freely with the increase of the impeller speed, and the occurrence of cavitation cannot be effectively avoided, which reduces the anti-cavitation performance of the centrifugal pump.

Utility model content

The embodiment of the utility model provides a centrifugal pump to solve the problem that the centrifugal pump in the prior art cannot freely compensate the fluid pressure at the inlet of the impeller with the increase of the impeller speed, which may cause cavitation and reduce the anti-cavitation performance of the centrifugal pump. question.

In order to solve the above technical problems, the embodiment of the utility model discloses the following technical solutions:

The embodiment of the present application provides a centrifugal pump, including: a pump body (3), a flange pipe (10) and an ejection device, and the ejection device is respectively connected to the pump body (3) and the flange pipe (10);

The pump body (3) is provided with a pump body inlet pipe (13) and a diffuser pipe (4), one end of the diffuser pipe (4) communicates with the pump body (3), and the other end is provided with a pump outlet (2 ), and the flanged pipe (10) is provided with a pump inlet (1);

The injection device includes a drainage pipeline and an incident pipeline, wherein,

One end of the drainage pipe communicates with the diffusion pipe (4), and the other end communicates with the incident pipe;

One end of the incident pipeline communicates with the pump body inlet pipe (13), and the other end communicates with the flange pipe (10), and the incident pipeline is connected to the pump body inlet pipe (13) and the flange respectively. Flexible connections between pipes (10).

Optionally, the incident pipeline includes a sleeve (11), both ends of the sleeve (11), and the pump body inlet pipe (13) connected to the sleeve (11) and the The connection positions of the flange pipes (10) are all provided with matingly connected threads.

Optionally, the casing (11) is provided with an incident cavity shell (12), and the incident cavity shell (12) communicates with the casing (11); wherein,

The incident cavity shell (12) is fixed around the sleeve (11), and the incident cavity (14) of the incident cavity shell (12) communicates with the inner cavity of the sleeve (11);

The drainage pipe is in communication with the incident cavity shell (12).

Optionally, an incident hole (15) is provided on the inner wall of the sleeve (11) in the circumferential direction, and the incident cavity (14) and the inner cavity of the sleeve (11) pass through the incident hole (15). The holes (15) are connected.

Optionally, the angle between the incident direction of the incident hole (15) and the axial direction of the casing (11) is 30°, and the incident direction of the incident hole (15) points to the pump body inlet tube (13).

Optionally, the casing (11) is provided with a plurality of incident holes (15), and the plurality of incident holes (15) are evenly distributed in the circumferential direction of the casing (11).

Optionally, the drainage pipeline includes a drainage tube (6), a drainage elbow (8) and a telescopic tube (9) connected in sequence, wherein,

One end of the drainage tube (6) is connected to the middle position of the diffuser tube (4) and communicated with the diffuser tube (4), and one end of the telescopic tube (9) is communicated with the incident pipeline.

Optionally, a regulating valve (7) is provided between the drainage pipe (6) and the drainage elbow (8), and the regulating valve (7) communicates with the drainage pipe (6) and the Drain elbow (8).

Optionally, the centrifugal pump further includes feet (5), and the feet (5) are fixed on the pump body (3).

It can be seen from the above technical solutions that the centrifugal pump provided by the embodiment of the present invention includes a pump body, a flange pipe and an ejection device, and the ejection device is respectively connected to the pump body and the flange pipe, wherein the pump body is provided with a An inlet pipe and a diffuser pipe, the injection device includes a drainage pipe and an incident pipe, one end of the drainage pipe communicates with the diffusion pipe, and the other end communicates with the incident pipe; one end of the incident pipe communicates with the inlet pipe of the pump body, and the other end communicates with the method blue pipe, and the incident pipe is respectively connected with the inlet pipe of the pump body and the flange pipe. Through the movable arrangement between the incident pipe and the inlet pipe of the pump body and the flange pipe, the incident pipe can move freely between the flange pipe and the pump body inlet pipe of the pump body, so that the drainage in the incident pipe can be shortened or lengthened The distance from the fluid to the impeller inlet in the pump body is equivalent to the free adjustment of the angle between the incident hole in the incident pipe and the impeller inlet, so as to adjust the incident effect when the high-pressure fluid enters the impeller inlet, so that the high-pressure fluid that is brought back has an impact on the impeller. The low-pressure fluid at the inlet is supplemented with energy to fully ensure that the pressure of the liquid is higher than the vaporization pressure of the liquid itself, avoiding cavitation, and effectively improving the anti-cavitation performance of the centrifugal pump.

Further, in the centrifugal pump provided by the embodiment of the present utility model, by setting a regulating valve in the drainage pipe and the drainage elbow, and connecting the drainage pipe and the drainage elbow through the regulating valve, the ejection flow can be freely adjusted through the regulating valve The size of the pump is used to compensate the low-pressure and low-energy fluid at the impeller inlet, so as to avoid the occurrence of cavitation and improve the anti-cavitation performance of the centrifugal pump as much as possible.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art In other words, other drawings can also be obtained from these drawings under the premise of not paying creative work.

Fig. 1 is a schematic structural view of a centrifugal pump provided by an embodiment of the present invention;

Fig. 2 is a schematic cross-sectional structure diagram of a centrifugal pump provided by an embodiment of the present invention.

Symbol means:

1-pump inlet, 2-pump outlet, 3-pump body, 4-diffusion tube, 5-foot, 6-drainage tube, 7-regulating valve, 8-drainage elbow, 9-telescopic tube, 10-flange Tube, 11-sleeve, 12-incidence cavity shell, 13-inlet pipe of pump body, 14-incidence cavity, 15-incidence hole.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution in the utility model, the technical solution in the utility model embodiment will be clearly and completely described below in conjunction with the accompanying drawings in the utility model embodiment. Obviously, The described embodiments are only some of the embodiments of the present utility model, but not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

Referring to Fig. 1, it is a schematic structural diagram of a centrifugal pump provided by an embodiment of the present utility model. As shown in the figure, the centrifugal pump includes a pump body 3, a flange pipe 10 and an injection device, and the injection device is respectively connected to the pump body 3 and flange pipe 10, through which the injection device drains high-pressure fluid into the pump body 3, so as to compensate the pressure of the low-pressure fluid at the inlet of the impeller in the pump body 3, realize weak cavitation or avoid the occurrence of cavitation, Thereby improving the anti-cavitation performance of the centrifugal pump.

The pump body 3 is provided with a pump body inlet pipe 13 and a diffuser pipe 4, one end of the diffuser pipe 4 communicates with the pump body 3 (i.e. at the position of the volute), and the other end of the diffuser pipe 4 is provided with a pump outlet; the diffuser pipe 4 is The device for converting kinetic energy into static pressure energy in the centrifugal pump, the diffusion pipe 4 is connected to the pump body 3, and the pipe diameter of the diffusion pipe 4 from the pump body 3 to the pump outlet 2 gradually expands; the flange pipe 10 One end is connected with the injection device, and the other end is provided with the pump inlet 1, so that the fluid enters the impeller inlet of the pump body 3 through the flange tube 10, the injection device and the pump body inlet pipe 13, and at the same time, the injection Under the action of the device, the injection device guides the high-pressure fluid flowing out of the impeller outlet in the pump body 3 to the impeller inlet, and performs pressure compensation for the low-pressure fluid entering the impeller inlet from the pump inlet 1.

In the centrifugal pump provided in this embodiment, the injection device includes a drainage pipe and an incident pipe, one end of the drainage pipe is connected to the diffuser pipe 4, and the other end is connected to the incident pipe, and the high-pressure fluid injected from the diffuser pipe 4 enters the drainage pipe , and enter the incident pipeline through the drainage pipeline; the incident pipeline is arranged between the inlet pipe 13 of the pump body and the flange pipe 10, and the incident pipe is flexibly connected to the connection between the inlet pipe 13 of the pump body and the flange pipe 10 , mainly used to transfer the high-pressure fluid drained by the drainage pipe and transport it to the impeller inlet of the pump body 3 to mix with the low-pressure fluid; since the incident pipe is flexibly connected with the pump body inlet pipe 13 and the flange pipe 10, as shown in Figure 1 Shown, the incident pipeline and the pump body inlet pipe 13 and the flange pipe 10 are threaded as an example, the incident pipeline can be screwed in or out between the pump body inlet pipe 13 and the flange pipe 10, and the incident pipeline and the flange pipe 10 are adjusted. The axial distance between the impeller inlets of the pump body 3 shortens or increases the axial distance for the high-pressure fluid to enter the impeller inlet, and improves the pressure compensation effect of the high-pressure fluid on the low-pressure fluid at the impeller inlet.

As shown in Figure 2, it is a schematic cross-sectional structure diagram of the centrifugal pump proposed in this embodiment, and referring to Figure 1, in the centrifugal pump proposed in this embodiment, the incident pipeline includes a casing 11, the two ends of the casing 11, and The positions of the pump body inlet pipe 13 and the flange pipe 10 connected with the sleeve pipe 11 are provided with matching threaded connections, wherein, as shown in the figure, the pump body inlet pipe 13 and the flange pipe 10 are all provided with External thread, the sleeve 11 is provided with an internal thread matched with the external thread, so that the sleeve 11 can move between the pump body inlet pipe 13 and the flange pipe 10 through the internal thread, shortening or increasing the high pressure Axial distance of incidence of the fluid.

The casing 11 also includes an incident cavity shell 12, which is fixed around the casing 11, and an incident cavity 14 is formed between the incident cavity shell 12 and the outer wall of the casing 11, and the incident cavity shell 12 is connected with the drainage pipe. The injection cavity shell 12 and the injection cavity 14 wrapped by the outer wall of the cannula 11 communicate with the inner cavity of the drainage tube, and the high-pressure fluid flowing through the drainage tube can enter the injection cavity 14 .

Since the incident cavity 14 communicates with the inner cavity of the sleeve 11, it is ensured that the high-pressure fluid in the incident cavity 14 can enter the sleeve 11 and flow to the impeller inlet of the pump body 3; In the casing 11, the casing 11 is provided with an incident hole 15, the incident hole 15 is arranged on the casing wall communicating with the incident cavity 14, and the incident hole 15 runs through the casing wall; the incident cavity 14 passes through the incident The hole 15 communicates with the inner cavity of the casing 11, and the high-pressure fluid is sprayed into the casing 11 through the injection hole 15, and merges with the low-pressure fluid at the inlet of the impeller to form pressure compensation for the low-pressure fluid.

As shown in Figure 2, in the centrifugal pump provided in this embodiment, a plurality of incident holes 15 are arranged on the same circumferential direction of the casing wall where the incident cavity 14 communicates, and the plurality of incident holes 15 are evenly distributed, so as to Twelve incident holes 15 are taken as an example, and the twelve incident holes 15 are uniformly distributed at intervals of 30° on the same circumferential direction of the casing wall (the 30° angle is a central angle in the circumferential direction of the casing wall, so that the Twelve incident holes 15) are arranged on the pipe wall. At the same time, the incident angle of the incident hole 15 is 30°, that is, the angle between the incident direction of the incident hole 15 and the axial direction of the casing 11 is 30°, and the incident direction points to the pump body inlet pipe 13, Therefore, the high-pressure fluid drained into the injection cavity 14 is directly introduced into the impeller inlet of the pump body 3, thereby improving the anti-cavitation performance. However, the number of incident holes 15 provided on the casing wall is not limited to twelve provided in this embodiment, and can also be set as multiple incident holes 15 such as 2, 4, 6, 8, 16, etc., as long as the The incident holes 15 can be evenly distributed on the casing wall in the same circumferential direction connected to the incident cavity 14; moreover, the included angle between the incident direction of the incident holes 15 and the casing wall is not limited to 30°, and the included angle can be set as Between 10° and 50°, however, in the centrifugal pump provided in this embodiment, under the condition that the included angle is constant, the distance between the casing 11 and the impeller inlet can be freely adjusted to improve the impact of the incident high-pressure fluid on the low-pressure fluid. energy compensation.

In the centrifugal pump provided in this embodiment, as shown in Figure 1, the drainage pipeline includes a drainage tube 6, a regulating valve 7, a drainage elbow 8 and a telescopic tube 9, wherein one end of the drainage tube 6 is connected to the diffusion tube 4 The middle position of the diffuser tube 4 is communicated with the inner cavity of the diffuser tube 4, the other end of the drainage tube 6 is connected with the drainage elbow 8, one end of the drainage elbow 8 is communicated with the drainage tube 6, and the other end is communicated with the telescopic tube 9, One end of the telescopic tube 9 communicates with the drainage elbow, and the other end is connected to the incident cavity shell 12 and communicated with the incident cavity 14 . The setting of the telescopic tube 9 is convenient for the sleeve tube 11 and the pump body fixing tube 13 to rotate, away from or close to the impeller inlet of the centrifugal pump, the telescopic tube 9 can be stretched or contracted, so that the sleeve tube 11 moves smoothly. Moreover, a regulating valve 7 is arranged between the drainage tube 6 and the drainage elbow 8, and the inner cavity of the drainage tube 6 and the drainage elbow 8 are communicated through the regulating valve 7, and the regulating valve 7 can freely adjust the injection flow rate. the size of.

In addition, in the centrifugal pump provided in this embodiment, the centrifugal pump also includes a foot 5, which is arranged at the bottom of the pump body 3 for fixedly supporting the pump body 3; of course, for supporting the pump body 3 The structure of the body 3 is not limited to the feet 5 proposed in this embodiment.

The centrifugal pump provided by this embodiment includes a pump body, a flange pipe, and an ejector device. The ejector device is connected to the pump body and the flange pipe respectively. The casing is connected with the inlet pipe of the pump body and the flange pipe freely, so that the casing can be screwed in or out freely, so as to flexibly adjust the incident position of the injection hole and improve the pressure of the high-pressure fluid. The energy compensation of the low-pressure fluid at the inlet of the impeller eliminates or weakens the occurrence of cavitation, thereby achieving the purpose of improving the anti-cavitation performance of the centrifugal pump.

Furthermore, the centrifugal pump provided by the embodiment of the utility model aims to improve the structure of the current conventional pump ejection device. With the aid of the ejector device of the centrifugal pump provided by this embodiment, the impeller inlet can be eliminated or weakened when the impeller rotates at high speed. cavitation phenomenon. Part of the high-energy fluid (or high-pressure fluid) in the diffuser pipe is introduced back to the impeller inlet of the pump body through the ejector device of the centrifugal pump provided in this embodiment, and the low-energy fluid (or low-pressure fluid) at the impeller inlet Energy supplementation is carried out to increase the fluid pressure, so that the mixed fluid is higher than the vaporization pressure of the low-pressure fluid pressure itself, so as to achieve the purpose of improving the anti-cavitation performance of the centrifugal pump.

Moreover, the regulating valve provided in the injection device in the centrifugal pump of this embodiment can freely adjust the flow rate of the high-pressure fluid led back by the drainage tube, and then can adjust the flow rate of the high-pressure fluid entering the impeller inlet through the incident hole provided on the casing. The flow rate can be adjusted to adjust the pressure of the high and low pressure mixed fluid, so as to avoid cavitation and effectively improve the anti-cavitation performance of the centrifugal pump.

The specific working mode of the centrifugal pump provided in this embodiment is: the fluid medium to be transported is sucked into the pump body through the pump inlet of the flange pipe, and the high-speed rotation of the impeller in the pump body acts on the fluid, and the transmission in the diffusion tube has high energy. The characteristic high-pressure fluid is output to the destination through the pump outlet. The drainage tube in the injection device of the centrifugal pump of the embodiment of the present application guides a part of the high-pressure fluid in the diffusion tube through the drainage tube, the regulating valve, the drainage elbow and the telescopic tube in sequence, and leads it back into the injection cavity, and passes through the injection cavity. Multiple injection holes evenly arranged on the connected casing wall spray high-pressure fluid to the impeller inlet of the pump body, thereby supplementing the energy of the low-pressure fluid flowing into the impeller inlet, eliminating or weakening the cavitation phenomenon at the impeller inlet, Improve the anti-cavitation performance of centrifugal pumps.

The casing in the injection device of the centrifugal pump of the present application is connected with the pump body inlet pipe and the flange pipe through threads, and the casing can be screwed in or out on the pump body inlet pipe and the flange pipe to adjust The axial distance between the casing and the impeller inlet of the pump body is to adjust the axial distance between the incident hole set on the casing and the impeller inlet; because the angle of the incident hole set on the casing is certain relative to the casing wall (30°), in the course of the incident hole changing with the distance between the incident hole and the impeller inlet, the angle of action between the high-pressure fluid flowing out of the incident hole and the low-pressure fluid at the impeller inlet changes, thereby improving the high pressure of the drainage The energy compensation effect of the fluid on the low-pressure fluid; therefore, the centrifugal pump provided by this embodiment can adjust the axial position of the casing to adapt to the rotational speed of the impeller in the pump body, and the injection device can be applied to various working conditions.

The above descriptions are only specific implementation methods of the present utility model, so that those skilled in the art can understand or realize the present utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims (9)

1. A centrifugal pump, characterized in that it comprises: a pump body (3), a flange pipe (10) and an ejection device, and the ejection device is connected to the pump body (3) and the flange pipe respectively (10); The pump body (3) is provided with a pump body inlet pipe (13) and a diffuser pipe (4), one end of the diffuser pipe (4) communicates with the pump body (3), and the other end is provided with a pump outlet (2 ), and the flanged pipe (10) is provided with a pump inlet (1); The injection device includes a drainage pipeline and an incident pipeline, wherein, One end of the drainage pipe communicates with the diffusion pipe (4), and the other end communicates with the incident pipe; One end of the incident pipeline communicates with the pump body inlet pipe (13), and the other end communicates with the flange pipe (10), and the incident pipeline is connected to the pump body inlet pipe (13) and the flange respectively. Flexible connections between pipes (10). 2. The centrifugal pump according to claim 1, characterized in that, the incident pipeline comprises a sleeve (11), two ends of the sleeve (11), and a pipe connected to the sleeve (11). The connection positions of the inlet pipe (13) of the pump body and the flange pipe (10) are all provided with matching threads. 3. The centrifugal pump according to claim 2, characterized in that, the casing (11) is provided with an incident cavity shell (12), and the incident cavity shell (12) communicates with the casing (11) ;in, The incident cavity shell (12) is fixed around the sleeve (11), and the incident cavity (14) of the incident cavity shell (12) communicates with the inner cavity of the sleeve (11); The drainage pipe is in communication with the incident cavity shell (12). 4. The centrifugal pump according to claim 3, characterized in that, the inner wall of the casing (11) is provided with an incident hole (15) in the circumferential direction, and the incident cavity (14) and the casing The inner cavities of (11) communicate with each other through the incident hole (15). 5. The centrifugal pump according to claim 4, characterized in that, the included angle between the incident direction of the incident hole (15) and the axial direction of the casing (11) is 30°, and the The incident direction of the incident hole (15) points to the pump body inlet pipe (13). 6. The centrifugal pump according to claim 4, characterized in that, the casing (11) is provided with a plurality of incident holes (15), and the plurality of incident holes (15) are evenly distributed in the sleeve In the circumferential direction of the pipe (11). 7. The centrifugal pump according to claim 1, characterized in that, the drainage pipeline comprises a drainage tube (6), a drainage elbow (8) and a telescopic tube (9) connected in sequence, wherein, One end of the drainage tube (6) is connected to the middle position of the diffuser tube (4) and communicated with the diffuser tube (4), and one end of the telescopic tube (9) is communicated with the incident pipeline. 8. The centrifugal pump according to claim 7, characterized in that, a regulating valve (7) is arranged between the drainage pipe (6) and the drainage elbow (8), and the regulating valve (7) The drainage pipe (6) and the drainage elbow (8) are connected respectively. 9. The centrifugal pump according to claim 1, characterized in that, the centrifugal pump further comprises a foot (5), and the foot (5) is fixed on the pump body (3).