CN218493826U

CN218493826U - High anti cavitation self-balancing's festival segmentation multistage pump

Info

Publication number: CN218493826U
Application number: CN202222506478.4U
Authority: CN
Inventors: 雍万喜; 强欢欢; 刘挺; 潘晶晶
Original assignee: Gansu Laideer Fluid Energy Saving Technology Development Co ltd
Current assignee: Gansu Laideer Fluid Energy Saving Technology Development Co ltd
Priority date: 2022-09-22
Filing date: 2022-09-22
Publication date: 2023-02-17
Anticipated expiration: 2032-09-22

Abstract

The utility model discloses a high cavitation resistance self-balancing sectional multistage pump, which comprises a suction box body, a primary impeller, a secondary water suction section, a discharge section, a pump shaft and a coupling; the suction box body and the secondary water suction section are arranged at two sides of the spitting section and are communicated through a flow passage; the first-stage impeller is arranged in the suction box body and comprises two groups of parallel centrifugal impellers which are fixedly connected, the two centrifugal impellers are arranged back to back, and liquid flow axially flows into the first-stage impeller from the left side and the right side through the suction box body; a secondary impeller and a guide vane are arranged between the suction box body and the secondary water suction section; a secondary reverse impeller and a reverse guide vane are arranged between the secondary water suction section and the discharge section; the secondary impeller, the secondary reverse impeller, the guide vanes and the reverse guide vanes are symmetrically arranged along the center line of the discharge section. The pump shaft is arranged on the central line of the pump shell and extends outwards along the end of the first-stage impeller to be connected with the coupling; the primary impeller, the secondary impeller and the secondary reverse impeller are all penetrated on the pump shaft and synchronously rotate along with the pump shaft through key connection.

Description

High anti cavitation self-balancing's festival segmentation multistage pump

Technical Field

The utility model belongs to the technical field of the multistage pump, concretely relates to festival segmentation multistage pump of high anti cavitation self-balancing.

Background

The multistage pump is widely applied to the industrial fields of electric power, steel, metallurgy, coal mines and the like, and along with the rapid development of the industrial fields, people have higher and higher requirements on the multistage pump on the cavitation resistance and the stability performance of the multistage pump besides the basic lift and efficiency. If the multi-stage pump has serious cavitation or fails in stability performance in the operation process, the multi-stage pump is forced to be shut down urgently, so that the whole industrial production system where the multi-stage pump is located is paralyzed, even unexpected disastrous results are generated, and the multi-stage pump plays a very important role in industrial production. Whether a multistage pump can have high cavitation resistance and good stability relates to various design requirements, wherein reasonable structural design is undoubtedly an important factor for ensuring cavitation performance and stability of the multistage pump.

The multistage pump is a high-lift pump, and the high-lift performance of the multistage pump is realized by connecting a plurality of centrifugal impellers in series and superposing the centrifugal impellers by applying work. However, the first-stage impeller of the multi-stage pump does not work by the previous-stage impeller to supplement the inlet pressure, so that the liquid flow pressure at the inlet of the first-stage impeller is very low, and when the liquid flow pressure is reduced to the local vaporization pressure, the first-stage impeller generates a cavitation phenomenon. Aiming at the problem of cavitation of the first-stage impeller of the multi-stage pump, a plurality of scholars optimize the geometric parameters of the first-stage impeller by properly moving the inlet edge of the first-stage impeller backwards or properly increasing the inlet diameter of the first-stage impeller and the like to enable the first-stage impeller to achieve better cavitation resistance, but the method is incomprehensible for special occasions with excessively high cavitation requirements or when the multi-stage pump needs to operate under an excessively large flow.

Traditional multistage pump is established ties a plurality of centrifugal impeller according to the order of same direction in proper order, axial force is very big when can leading to multistage pump operation like this, for this very big axial force of balance, generally balance the axial force through installing the balance plate additional, however under the unstable condition of a series of operating condition such as start-up process when the pump, the axial force can frequent change make the frequent axial pulsation of rotor part cause the balance plate to take place the friction in the twinkling of an eye, lead to the balance plate locking to generate heat, so that the balance plate destroys and takes place pump shaft rupture phenomenon even. In order to prevent the balance disc from being locked, a learner properly restricts axial pulsation by introducing an angular contact ball bearing, the introduction of the angular contact ball bearing limits the dynamic balance function of the balance disc, and the balance disc is additionally provided with a balance disc device to balance axial force, so that backflow leakage of balance liquid flow exists, the volume loss of the multistage pump is increased undoubtedly, and the working efficiency of the multistage pump is reduced.

SUMMERY OF THE UTILITY MODEL

The utility model provides a festival segmentation multistage pump of high anti cavitation self-balancing, aim at improve multistage pump anti cavitation erosion performance, prevent that multistage pump operation process axial force from too big leading to the rotor part frequent axial pulsation phenomenon to appear, and then improve the reliability and the stability of multistage pump operation.

Therefore, the utility model adopts the following technical scheme:

a high cavitation resistance self-balancing sectional type multistage pump comprises a suction box body, a primary impeller, a secondary water suction section, a discharge section, a pump shaft and a coupling;

the suction box body and the secondary water absorption section are positioned at the front side and the rear side of the spitting section; the first-stage impeller is arranged in the suction box body and comprises two groups of centrifugal impellers which are parallel and fixedly connected, the two centrifugal impellers are arranged back to back, and liquid flow axially flows into the first-stage impeller from the left side and the right side through the suction box body;

a secondary impeller and a guide vane are arranged between the suction box body and the secondary water suction section;

a secondary reverse impeller and a reverse guide vane are arranged between the secondary water suction section and the discharge section; the secondary impeller, the secondary reverse impeller, the guide vanes and the reverse guide vanes are symmetrically arranged along the center line of the discharge section.

The pump shaft is arranged on the central line of the pump shell and extends outwards along the end of the first-stage impeller to be connected with the coupling; the primary impeller, the secondary impeller and the secondary reverse impeller are all penetrated on the pump shaft and synchronously rotate along with the pump shaft through key connection. Furthermore, the liquid flow inflow direction of the suction box body is perpendicular to the axial center line of the pump shaft, and the liquid flow outflow direction of the spitting section is perpendicular to the axial center line of the pump shaft and perpendicular to the liquid flow inflow direction of the suction box body.

Further, the number of the intermediate sections between the suction and discharge sections is equal to the number of the intermediate sections between the secondary water absorption section and the discharge section.

Furthermore, the guide vanes are arranged at the outlet of the secondary impeller and the rear cover plate; the reverse guide vane is arranged at the outlet of the reverse impeller and the rear cover plate.

Further, the guide vanes and the secondary impellers, and the reverse guide vanes and the reverse secondary impellers are the same in number. The secondary impeller and the secondary reverse impeller blades are three-dimensional twisted blades. The guide vane and the reverse guide vane are radial guide vanes, and the appearance of the vane is spiral.

The number of the secondary impellers and the number of the secondary reverse impellers are the same or less than 1 group (when the number of the secondary impellers is odd). The secondary water suction section is arranged on one side far away from the coupling and is connected with the pump shaft in a sealing mode through a mechanical sealing part.

The beneficial effects of the utility model reside in that:

1. the traditional first-stage centrifugal impeller is replaced by the back-to-back double-suction impeller, the overflowing area of liquid flow entering the impeller is increased, the speed is reduced, the cavitation performance of the first-stage impeller is effectively improved, the double-suction impeller is arranged in a back-to-back mode, and the directions of axial forces generated by the two impellers are opposite and offset with each other, so that the self-balance of the axial force of the first-stage impeller of the sectional type multi-stage pump is realized, and the long-term stable and reliable operation of the sectional type multi-stage pump is facilitated;

2. by replacing a novel suction box body of a traditional water suction chamber, the smooth double-channel suction mode increases the inflow volume of liquid flow, reduces the loss caused by vortex and impact before the liquid flow enters the first-stage impeller, and improves the cavitation performance and efficiency of the pump;

3. the traditional balance disc structure for balancing the axial force is cancelled, the number of the secondary impellers is divided into two parts, the secondary water suction section is introduced, the discharge section is just arranged at the position of half of the number of the secondary impellers, the secondary impellers are symmetrically distributed along the center line of the discharge section, the axial forces generated by the secondary impellers at two sides of the discharge section are mutually offset, and the self-balancing of the axial force generated by the secondary impellers of the sectional multi-stage pump is realized;

4. after the structure of the balance disc is cancelled, instantaneous friction and frequent axial pulsation of the balance disc disappear, the centering performance of the secondary impeller and the guide vane is in a better state, and the problems of locking of the original balance disc, backflow leakage of balance liquid flow, reduction of volume loss, reduction of shaft power and the like are avoided; thereby ensuring that the sectional type multistage pump has high cavitation resistance and long-term stable and reliable operation.

Drawings

FIG. 1 is a sectional view of a multistage pump of the present invention;

FIG. 2 is a schematic structural view of the first-stage impeller of the present invention;

FIG. 3 is a front view of FIG. 2;

FIG. 4 is a left side view of FIG. 2;

FIG. 5 is a schematic view of the inlet of the suction box;

in the figure: 1-shaft coupling, 2-drive side bearing cap, 3-drive side bearing, 4-drive side bearing housing, 5-drive side mechanical seal component, 6-pump shaft, 7-suction box, 8-primary impeller, 9-secondary impeller, 10-middle section, 11-guide vane, 12-discharge section, 13-reverse guide vane, 14-secondary reverse impeller, 15-secondary suction section, 16-non-drive side mechanical seal component, 17-non-drive side bearing, 18-non-drive side bearing housing, 19-non-drive side bearing cap.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings:

as shown in FIG. 1, the segmented multistage pump of this embodiment can be used to deliver a liquid having a solids concentration of no greater than 2% (particle size less than 1 mm), a media solids concentration of less than 5% wt, and a temperature of 210 ℃ or less.

The utility model discloses to festival segmentation multistage pump design first level double suction impeller 8 and with double suction impeller assorted novel suction letter body 7 structure

Referring to fig. 2-4, the utility model is based on the traditional sectional multistage pump, the first-stage impeller is designed into the double-suction impeller 8 in a back-to-back manner, and the suction chamber is designed into the novel suction box body 7 matched with the double-suction impeller. The first-stage double-suction impeller 8 is connected on the pump shaft 6 through a key and synchronously rotates along with the pump shaft, the suction box body 7 is arranged outside the first-stage double-suction impeller 8, the central line of the inlet of the suction box body 7 is perpendicular to the axial central line of the pump shaft 6 and is also perpendicularly arranged with the central line of the spitting section 12, namely the installation form of the multistage pump is liquid flow horizontal inlet and vertical outlet when being seen from the motor direction. The liquid flow flows in from the inlet of the suction box body 7, passes through the smooth flow channel of the suction box body, is uniformly divided into two parts at the middle bracket of the suction box body, respectively flows into the inlet of the first-stage double-suction impeller 8 through the left and right flow channels of the suction box body, works through the double-suction impeller to send out the two parts of liquid flow, and the two parts of liquid flow at the outlet of the first-stage double-suction impeller are combined into one and enter the secondary impeller through the outer flow channel of the suction box body 7. The first-stage impeller is designed into the double-suction impeller 8, the area of the inlet of the impeller is increased, and liquid flow is decelerated and pressurized through the impeller, so that the pump can operate under the working condition of higher flow, the operating condition of the pump is widened, and the cavitation resistance of the first-stage impeller 8 is improved; the water suction chamber is designed into a novel suction box body 7 structure matched with the double-suction impeller, liquid flow can be uniformly divided into a left part and a right part, the left part and the right part are led into the first-stage double-suction impeller (as shown in figure 5) from a left flow channel and a right flow channel with the minimum loss, the loss generated by vortex and impact is reduced, and the circumferential smooth flow channel of the suction box body 7 collects the liquid flow at the outlet of the first-stage double-suction impeller 8 and leads the liquid flow into the next-stage impeller with the minimum loss, so that the cavitation resistance and the efficiency of the pump are improved.

The utility model discloses cancel the tradition and be used for balanced axial force's balance disk structure, designed a novel secondary impeller number structure of arranging for two back to back.

Referring to fig. 1, the utility model eliminates the traditional balance disc structure for balancing the axial force, divides the number of secondary impellers into two and arranges them back to back, introduces the secondary water suction section 15, arranges the discharge section 12 at the position of half the number of secondary impellers, herein still refers to the secondary impeller 9 at the left side of the discharge section 12, and refers to the secondary reverse impeller 14 at the right side of the discharge section because the secondary impeller at the right side of the discharge section is arranged in a reverse manner relative to the secondary impeller at the left side. The arrangement mode cancels a balance disc structure, so that the pump structure is simpler and more compact, and the axial force generated by the liquid flow passing through the secondary impeller is just opposite to the axial force generated by the secondary reverse impeller, and the two forces are just mutually offset, therefore, the structure can well realize the self-balance of the axial force; after the small-gap balance disc is eliminated, the multi-stage pump can convey liquid flow containing certain particles or with high concentration, so that the types of media which can be conveyed by the multi-stage pump are increased; and the back flow leakage of the liquid flow of the balance gap is avoided after the balance disc is eliminated, so that the operation efficiency of the multistage pump is improved. Therefore, the novel structure that the secondary impellers are arranged back to back for one part can ensure that the sectional type multistage pump can run more stably and reliably.

Claims

1. A high cavitation resistance self-balancing sectional type multistage pump is characterized by comprising a suction box body (7), a primary impeller (8), a secondary water suction section (15), a discharge section (12), a pump shaft (6) and a coupling (1);

the suction box body (7) and the secondary water absorption section (15) are positioned at the front side and the rear side of the discharge section (12); the first-stage impeller (8) is arranged in the suction box body (7), the first-stage impeller (8) comprises two groups of centrifugal impellers which are parallel and fixedly connected, the two centrifugal impellers are arranged back to back, and liquid flow axially flows into the first-stage impeller (8) from the left side and the right side through the suction box body (7);

a secondary impeller (9) and a guide vane (11) are arranged between the suction box body (7) and the secondary water suction section (15);

a secondary reverse impeller (14) and a reverse guide vane (13) are arranged between the secondary water suction section (15) and the discharge section (12); the secondary impeller (9), the secondary reverse impeller (14), the guide vanes (11) and the reverse guide vanes (13) are symmetrically arranged along the central line of the spitting section (12).

2. The segmented multistage pump with high cavitation resistance and self balancing according to claim 1, characterized in that the pump shaft (6) is arranged on the central line of the pump shell and extends outwards along the end of the first-stage impeller (8) to be connected with the coupling (1); the primary impeller (8), the secondary impeller (9) and the secondary reverse impeller (14) are all penetrated on the pump shaft (6) and synchronously rotate along with the pump shaft (6) through key connection.

3. The segmented multi-stage pump with high cavitation resistance and self-balancing according to claim 1, characterized in that the inflow direction of the liquid flow of the intake union (7) is perpendicular to the axial center line of the pump shaft (6), and the outflow direction of the liquid flow of the discharge segment (12) is perpendicular to the axial center line of the pump shaft (6) and perpendicular to the inflow direction of the liquid flow of the intake union (7).

4. Sectional multistage pump of high cavitation resistance and self-balancing according to claim 1, characterized in that the number of intermediate sections between the suction box (7) and the discharge section (12) is equal to the number of intermediate sections between the secondary suction section (15) and the discharge section (12).

5. The high cavitation erosion resistance self-balancing segmented multistage pump according to claim 1, characterized in that the guide vanes (11) are provided at the secondary impeller (9) outlet and at the back cover plate; the reverse guide vane (13) is arranged at the outlet of the reverse impeller and the rear cover plate.

6. The segmented multistage pump with high cavitation resistance and self balancing according to claim 1, characterized in that the number of guide vanes (11) and secondary impellers (9) and the number of reverse guide vanes (13) and reverse secondary impellers (9) are the same.