A rotary jet pump

Abstract

The present application relates to a rotary jet pump, comprising a pump cover, a cover plate, an impeller, a roller, a bearing body, a liquid collecting pipe, a mechanical seal, and a suction shaft. The pump cover is provided with a fluid inlet and a fluid outlet, and the outlet of the liquid collecting pipe is connected to the fluid outlet. The cover plate and the bearing body form a rotor cavity, the impeller and the roller are located inside the rotor cavity, the impeller and the roller form a rotating cavity, and the liquid collecting pipe is located inside the rotating cavity. The mechanical seal and the suction shaft are located between the pump cover and the impeller, the inlet of the suction shaft is connected to the fluid inlet, and the outer surface of the suction shaft is provided with a spiral sealing structure. Both the mechanical seal and the spiral sealing structure are used to prevent fluid leakage. The rotary jet pump can increase the service life of the sealing structure and improve the anti-cavitation performance.

Description

Technical Field

[0001] The present application relates to the technical field of fluid equipment, and in particular to a rotary jet pump. Background Art

[0002] Jet-jet pumps serve numerous national sectors, including aerospace, petrochemicals, and coal chemical industries. They offer advantages unmatched by conventional centrifugal and positive displacement pumps, including low flow rates, high head, high efficiency, and zero pulsation. As a rotating device, a jet-jet pump requires a sealed structure between the moving and stationary parts. Furthermore, as a fluid conveying device, improving its cavitation resistance can effectively reduce pipeline pressure in the conveying system, reducing project costs and enhancing product competitiveness.

[0003] In the existing technology, mechanical seals and inducers are generally used as sealing structures and to improve cavitation performance in rotary jet pumps. However, when conveying high-temperature media containing solid particles, mechanical seals are prone to failure and aging in a short period of time under the combined action of solid particles and high temperature. When conveying high-temperature fluid media, cavitation is prone to occur at the inlet of the pump, affecting the performance and life of the pump. Summary of the Invention

[0004] The embodiment of the present application provides a rotary jet pump, which can achieve a sealing effect, increase the service life of the sealing structure, and improve the anti-cavitation performance.

[0005] The embodiment of the present application provides a rotary jet pump, comprising a pump cover, a cover plate, an impeller, a roller, a bearing body, a liquid collecting pipe, a mechanical seal and a suction shaft;

[0006] The pump cover is connected to the cover plate and the liquid collecting pipe respectively;

[0007] The pump cover is provided with a fluid inlet end and a fluid outlet end, and the outlet of the collecting pipe is communicated with the fluid outlet end;

[0008] The cover plate and the bearing body form a rotor cavity, the impeller and the roller are located inside the rotor cavity, the impeller and the roller form a rotating cavity, and the collecting pipe is located inside the rotating cavity;

[0009] The mechanical seal and the suction shaft are located between the pump cover and the impeller. The inlet of the suction shaft is connected to the fluid inlet end. A spiral sealing structure is provided on the outer surface of the suction shaft. Both the mechanical seal and the spiral sealing structure are used to prevent fluid leakage.

[0010] Furthermore, a blade structure is provided on the inner surface of the suction shaft, and the blade structure is used to increase the kinetic energy of the fluid.

[0011] Furthermore, the blade structure includes a plurality of blades, and the widths of the plurality of blades increase sequentially along the direction in which the fluid enters.

[0012] Furthermore, the multiple blades include a first blade and a second blade; the gap between the outlet inner diameter of the first blade and the second blade and the outlet outer diameter of the collecting pipe is less than or equal to a first preset value; the gap between the inlet inner diameter of the first blade and the second blade and the outlet outer diameter of the collecting pipe is greater than or equal to 0.95 times the first preset value.

[0013] Furthermore, the spiral sealing structure includes a spiral sealing blade; or the spiral sealing structure includes an internally threaded sealing sleeve; the pump cover is provided with an externally threaded sealing sleeve matching the internally threaded sealing sleeve.

[0014] Furthermore, the rotary jet pump also includes a first fixing member; the suction shaft also includes a pillow block and a through hole; the mechanical seal is arranged between the pillow block and the pump cover; the first transmission screw is used to pass through the through hole to connect the suction shaft and the impeller.

[0015] Furthermore, the rotary jet pump also includes an O-ring; the O-ring is located between the impeller and the liquid collecting pipe, and the O-ring is installed on the liquid collecting pipe through an interference fit.

[0016] Furthermore, the rotary jet pump also includes a pump shaft; one end of the pump shaft extends into the rotor cavity and is connected to the drum, and the pump shaft is used to drive the rotating cavity to rotate.

[0017] Furthermore, the rotary jet pump also includes a bearing end cover and a sealing ring; the bearing end cover is connected to the bearing body through a second fixing member; and the sealing ring is arranged between the bearing end cover and the pump shaft.

[0018] Furthermore, the rotary jet pump further includes a rolling bearing; the rolling bearing is sleeved on the outer side of the pump shaft and abuts against the inner side of the bearing body.

[0019] The rotary jet pump provided in the embodiment of the present application has the following beneficial effects:

[0020] The rotary jet pump includes a pump cover, a cover plate, an impeller, a roller, a bearing body, a liquid collecting pipe, a mechanical seal, and a suction shaft. The pump cover is provided with a fluid inlet and a fluid outlet, and the outlet of the liquid collecting pipe is connected to the fluid outlet. The cover plate and the bearing body form a rotor cavity, and the impeller and the roller are located within the rotor cavity. The impeller and the roller form a rotating cavity, and the liquid collecting pipe is located within the rotating cavity. The mechanical seal and the suction shaft are located between the pump cover and the impeller, and the inlet of the suction shaft is connected to the fluid inlet. The outer surface of the suction shaft is provided with a spiral seal structure. Both the mechanical seal and the spiral seal structure are used to prevent fluid leakage. This rotary jet pump can increase the service life of the sealing structure and improve the anti-cavitation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1 This is a structural diagram of a rotary jet pump provided in an embodiment of the present application;

[0023] Figure 2 It is a cross-sectional view of an intake shaft provided by the present application;

[0024] Figure 3 is a side view of an intake shaft provided in an embodiment of the present application;

[0025] Figure 4 This is a schematic structural diagram of another suction shaft provided by the present application;

[0026] Figure 5 This is a bottom view of a blade structure provided in an embodiment of the present application;

[0027] Figure 6 This is a three-dimensional schematic diagram of a blade structure provided in an embodiment of the present application;

[0028] Figure 7 This is a comparison chart of the cavitation margin performance of the rotary jet pump of the present application and the traditional rotary jet pump;

[0029] Description of reference numerals:

[0030] 1- pump cover; 2- second fixing piece; 3- cover plate; 4- impeller; 5- roller; 6- bearing body; 6a- discharge hole; 7- third fixing piece; 8- bearing end cover; 9- sealing ring; 10- rolling bearing; 11- locking retaining ring; 12- pump shaft; 13- fourth fixing piece; 14- lifting ring; 15- fifth fixing piece; 16- sixth fixing piece; 17- collecting pipe; 18- first fixing piece; 19- mechanical seal; 20- suction shaft; 20a- spiral sealing structure; 20b- first blade; 20c- second blade; 20d- pillow block; 20e- through hole; 21- gasket; 22- seventh fixing piece; 23- spring gasket; 24- sealing cover; 25- O-ring. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0032] like Figure 1As shown, the embodiment of the present application provides a rotary jet pump, including a pump cover 1, a cover plate 3, an impeller 4, a roller 5, a bearing body 6, a liquid collecting pipe 17, a mechanical seal 19 and a suction shaft 20;

[0033] The pump cover 1 is connected to the cover plate 3 and the liquid collecting pipe 17 respectively;

[0034] The pump cover 1 is provided with a fluid inlet end and a fluid outlet end, and the outlet of the liquid collecting pipe 17 is connected to the fluid outlet end;

[0035] The cover plate 3 and the bearing body 6 form a rotor cavity, the impeller 4 and the roller 5 are located inside the rotor cavity, the impeller 4 and the roller 5 form a rotating cavity, and the collecting pipe 17 is located inside the rotating cavity;

[0036] The mechanical seal 19 and the suction shaft 20 are located between the pump cover 1 and the impeller 4. The inlet of the suction shaft 20 is connected to the fluid inlet end. A spiral sealing structure 20a is provided on the outer surface of the suction shaft 20. Both the mechanical seal 19 and the spiral sealing structure 20a are used to prevent fluid leakage.

[0037] The present application forms a spiral seal through the spiral sealing structure 20a on the outer surface of the suction shaft 20. Spiral seal is a form of contactless dynamic seal. By setting a spiral groove on the rotating shaft, the rotation of the shaft causes the spiral groove to produce a conveying effect similar to that of a pump, thereby preventing the leakage of the sealing liquid. In this way, the present application can ensure that under the condition that the overall structure of the traditional rotary spray pump remains unchanged, the spiral sealing structure 20a on the outer surface of the suction shaft 20 cooperates with the mechanical seal 19, not only achieving a double sealing effect, but also protecting the mechanical seal 19 from the influence of solid particles; at the same time, the mechanical seal 19 is away from the mainstream area in the flow channel, which can avoid the high temperature influence of the fluid medium, reduce the thermal fatigue strength of the mechanical seal 19, greatly improve the service life of the mechanical seal 19, and further, reduce the selection criteria and use cost of the mechanical seal 19.

[0038] In an optional embodiment, as Figure 2 and Figure 3 As shown, Figure 2 This is a cross-sectional view of a suction shaft 20 provided by the present application. Figure 3 This is a side view of a suction shaft 20 provided in an embodiment of the present application. The spiral sealing structure 20a is a spiral sealing blade arranged on the outer surface of the suction shaft 20. A spiral groove is formed between the spiral sealing blades, and its rotation direction is determined by the actual rotation direction of the impeller 4; the sparseness and number of the spiral sealing blades can be set according to actual conditions.

[0039] Specifically, the cross-section of the spiral groove may be a rectangular groove, a trapezoidal groove, a triangular groove, or an arc groove.

[0040] In another optional embodiment, as Figure 4 As shown, Figure 4 This is a schematic diagram of the structure of another suction shaft 20 provided in the present application. The spiral seal structure 20a is an internally threaded sealing sleeve sleeved onto the outer wall of the outlet of the manifold 17. Correspondingly, an externally threaded sealing sleeve is provided on the side of the pump cover 1 near the outer wall of the outlet of the manifold 17, which mates with the internally threaded sealing sleeve. The external surface of the internally threaded sealing sleeve is provided with an external spiral groove axially extending therefrom, while the internal surface of the externally threaded sealing sleeve is provided with an internal spiral groove axially extending therefrom. The internal and external spiral grooves are of equal size and have the same rotational direction. The dual action of the internal and external spiral sealing sleeves prevents leakage of the fluid medium into the rotor cavity.

[0041] Specifically, the cross-section of the outer spiral groove on the inner spiral sealing sleeve and the inner spiral groove on the outer spiral sealing sleeve may be a rectangular groove, a trapezoidal groove, a triangular groove or an arc groove.

[0042] In an optional embodiment, the inner surface of the suction shaft 20 is provided with a blade structure that increases the kinetic energy of the fluid. As the fluid passes through the suction shaft 20, the blade structure increases the fluid energy, thereby improving the pump's anti-cavitation capabilities, reducing the fluid inlet pressure and installation height of the jet pump, and lowering the cost of associated pump piping.

[0043] In a specific embodiment, the blade structure includes a plurality of blades, and the widths of the plurality of blades increase in sequence according to the direction in which the fluid enters. Figure 5 and Figure 6 As shown, Figure 5 This is a bottom view of a blade structure provided in an embodiment of the present application. Figure 6 This is a perspective schematic diagram of a blade structure provided in an embodiment of the present application. The multiple blades may include a first blade 20b and a second blade 20c. The clearance between the outlet inner diameter of the first blade 20b and the second blade 20c and the outlet outer diameter of the manifold 17 is less than or equal to a first preset value. The clearance between the inlet inner diameter of the first blade 20b and the second blade 20c and the outlet outer diameter of the manifold 17 is greater than or equal to 0.95 times the first preset value. Specifically, the first preset value is 0.5 mm.

[0044] In an optional embodiment, as Figure 1 As shown, the rotary spray pump further includes a first fixing member 18; Figure 2 、 Figure 3 、 Figure 5 and Figure 6 As shown, the suction shaft 20 may further include a pillow block 20d and a through hole 20e; the mechanical seal 19 is provided between the pillow block 20d and the pump cover 1; the first transmission screw 18 is used to pass through the through hole 20e to connect the suction shaft 20 and the impeller 4.

[0045] In an optional embodiment, as Figure 1 As shown, the rotary spray pump further includes an O-ring 25 ; the O-ring 25 is located between the impeller 4 and the liquid collecting pipe 17 , and the O-ring 25 is installed on the liquid collecting pipe 17 by interference fit.

[0046] In an optional embodiment, as Figure 1 As shown, the rotary jet pump further includes a pump shaft 12; one end of the pump shaft 12 extends into the rotor cavity and is connected to the drum 5, and the pump shaft 12 is used to drive the rotating cavity to rotate.

[0047] Specifically, if the inlet of the collecting pipe 17 faces outward, the spiral direction of the spiral sealing structure 20a is opposite to the rotation direction of the impeller 4, otherwise it is the opposite; for example, when the impeller 4 rotates in the clockwise direction when viewed from the end of the suction shaft 20 to the end of the pump shaft 12, the spiral direction of the spiral sealing structure 20a is counterclockwise.

[0048] In an optional embodiment, as Figure 1 As shown, the rotary spray pump further includes a bearing end cover 8 and a sealing ring 9 ; the bearing end cover 8 is connected to the bearing body 6 via a second fixing member 7 ; the sealing ring 9 is provided between the bearing end cover 8 and the pump shaft 12 .

[0049] In a specific embodiment, the bearing body 6 is further provided with a hanging ring 14 , and a discharge hole 6 a is further provided on a side of the bearing body 6 away from the hanging ring 14 .

[0050] In an optional embodiment, as Figure 1 As shown, the rotary jet pump further includes a rolling bearing 10 ; the rolling bearing 10 is sleeved on the outer side of the pump shaft 12 and abuts against the inner side of the bearing body 6 .

[0051] In an optional embodiment, as Figure 1 As shown, the rotary spray pump further includes a second fixing member 2, a third fixing member 7, a fourth fixing member 13, a fifth fixing member 15, a sixth fixing member 16 and a seventh fixing member 22;

[0052] The second fixing member 2 is used to connect the pump cover 1 and the cover plate 3; the third fixing member 7 is used to connect the bearing body 6 and the bearing end cover 8; the fourth fixing member 13 is used to connect the roller 5 and the pump shaft 12; the fifth fixing member 15 is used to connect the cover plate 3 and the bearing body 6; the sixth fixing member 16 is used to connect the roller 5 and the impeller 4; the seventh fixing member 22 is used to connect the sealing cover 24 and the pump cover 1.

[0053] Specifically, the second fixing member 2 , the third fixing member 7 , the fifth fixing member 15 , the sixth fixing member 16 and the seventh fixing member 22 may be bolts, and the fourth fixing member 13 and the first fixing member 18 may be transmission screws.

[0054] In an optional embodiment, as Figure 1As shown, the rotary jet pump further includes a locking ring 11 , which is sleeved on the outer side of the pump shaft 12 and abuts against the side of the rolling bearing 10 away from the rotor cavity.

[0055] Based on the above optional implementation methods, the working process of the rotary jet pump of this application is as follows:

[0056] Under the action of the rotating centrifugal force of the impeller 4, the high temperature fluid medium containing solid particles passes through the inlet pipe of the pump. Figure 1 As shown, the fluid enters from the lower right corner of the pump cover 1 and flows along the flow channel to the inlet of the suction shaft 20; then, under the action of the first blade 20b and the second blade 20c, it passes through the suction shaft 20 and the flow channel of the collecting pipe 17, the energy of the fluid medium increases, and the anti-cavitation performance of the fluid medium increases; then, under the action of the centrifugal force of the rotating impeller 4, the energy of the fluid medium continues to increase, and after the pressure increases, it enters the rotating cavity formed by the roller 5 and the impeller 4, and then the high-pressure fluid medium enters the collecting pipe 17 through the inlet of the collecting pipe 17; finally, the fluid medium in the collecting pipe 17 flows into the outlet flow channel of the pump and is discharged at the upper right corner of the pump cover 1. Under the action of the spiral sealing structure 20a, the high-temperature medium containing solid particles can be driven to Figure 1 The right direction of the flow in the middle plays a certain sealing role, and also avoids the solid particles from entering the sealing surface of the mechanical seal 19 to cause damage, so that the service life of the rotary spray pump sealing structure can be improved.

[0057] A rotary jet pump provided in an embodiment of the present application can reduce the damage of solid particles to the sealing structure through the suction shaft 20 and the spiral sealing structure 20a when conveying a fluid medium containing high-temperature solid particles, thereby improving the sealing effect of the rotary jet pump and increasing the service life by more than 2 times compared with traditional mechanical seals.

[0058] In addition, the anti-cavitation performance of the rotary jet pump can be improved by the blade structure inside the suction shaft 20. Figure 7 As shown, Figure 7 This is a comparison chart of the cavitation margin performance of the rotary jet pump in this application and the traditional rotary jet pump. The chart mainly compares the cavitation performance data tested by the standard test bench, and analyzes and compares the design flow rate of 5m 3 / h~30m 3 / h NPSH value, as shown in the figure, compared with the traditional rotary jet pump, when the design point flow rate is 20m 3 / h, the cavitation head (NPSH) of this application is reduced by 2m and the cavitation performance is improved by 40%.

[0059] In summary, the rotary jet pump provided in the embodiment of the present application can not only achieve a sealing effect and increase the service life of the sealing structure, but also improve the anti-cavitation performance.

[0060] It should be noted that the order of the embodiments of the present application is for descriptive purposes only and does not represent the superiority or inferiority of the embodiments. The above description is of specific embodiments of this specification. Other embodiments are within the scope of the appended claims. The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A rotary jet pump, comprising a pump cover (1), a cover plate (3), an impeller (4), a roller (5), a bearing body (6), a liquid collecting pipe (17), a mechanical seal (19) and a suction shaft (20); the pump cover is connected to the cover plate and the liquid collecting pipe respectively; the pump cover is provided with a fluid inlet end and a fluid outlet end, and the outlet of the liquid collecting pipe is communicated with the fluid outlet end; the cover plate and the bearing body form a rotor cavity, the impeller and the roller are located inside the rotor cavity, the impeller and the roller form a rotating cavity, and the liquid collecting pipe is located inside the rotating cavity; the mechanical seal and the suction shaft are located between the pump cover and the impeller, and the inlet of the suction shaft is communicated with the fluid inlet end; Its characteristics are: The suction shaft (20) is connected to the impeller via a first transmission screw (18); a spiral sealing structure (20a) is provided on the outer surface of the suction shaft; the spiral sealing structure comprises an internal thread sealing sleeve, the outer surface of which is axially provided with an external spiral groove; an inner circumferential surface of the pump cover (1) is provided with an external thread sealing sleeve that matches the internal thread sealing sleeve, and the inner surface of which is axially provided with an internal spiral groove; A blade structure is provided on the inner surface of the suction shaft, and the blade structure is used to increase the kinetic energy of the fluid. The blade structure includes a plurality of blades, and the widths of the plurality of blades increase in sequence according to the fluid entry direction.

2. The rotary spray pump according to claim 1, characterized in that The plurality of blades include a first blade (20b) and a second blade (20c), wherein the gap between the outlet inner diameters of the first blade and the second blade and the outlet outer diameter of the collecting pipe is less than or equal to a first preset value; and the gap between the inlet inner diameters of the first blade and the second blade and the outlet outer diameter of the collecting pipe is greater than or equal to 0.95 times the first preset value, and the first preset value is 0.5 mm.

3. The rotary spray pump according to claim 2, characterized in that: If the collecting pipe inlet faces outward, the spiral direction of the spiral sealing structure is opposite to the direction of rotation of the impeller; otherwise, it is the opposite; that is, when the impeller rotates clockwise when viewed from the suction shaft end to the pump shaft end, the spiral direction of the spiral sealing structure is counterclockwise.

4. The rotary spray pump according to claim 2, characterized in that The inner spiral groove and the outer spiral groove have the same size and the same rotation direction.

5. The rotary spray pump according to claim 1, characterized in that: The suction shaft further comprises a pillow block (20d) and a through hole (20e); a mechanical seal is arranged between the pillow block and the pump cover; and a first transmission screw is used to pass through the through hole to connect the suction shaft and the impeller.

6. The rotary spray pump according to claim 5, characterized in that: It also includes an O-type sealing ring (25); the O-type sealing ring is located between the impeller and the liquid collecting pipe, and the O-type sealing ring is installed on the liquid collecting pipe through interference fit.

7. The rotary spray pump according to claim 6, characterized in that The invention also includes a pump shaft (12), a bearing end cover (8), a sealing ring (9), and a rolling bearing (10); one end of the pump shaft extends into the rotor cavity and is connected to the roller, and the pump shaft is used to drive the rotating cavity to rotate; the bearing end cover is connected to the bearing body through a second fixing member (7), and the sealing ring is arranged between the bearing end cover and the pump shaft; the rolling bearing is sleeved on the outer side of the pump shaft and abuts against the inner side of the bearing body.

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