A high-efficiency jet pump with backflow prevention

Abstract

The present invention belongs to the technical field of jet pumps, and discloses a high-efficiency jet pump with backflow prevention, comprising a liquid inlet pipe, a suction chamber, a nozzle, a throat pipe, a diffuser, an overflow pipe and a valve; the inner wall of the throat pipe is provided with a fracture in the middle of the fluid channel, the outer wall of the throat pipe is provided with an overflow port at one end close to the diffuser, and one end of the overflow port is connected to the overflow port. The jet pump of the present invention prevents the jet pump from backflowing out of the suction port through the fracture and the overflow pipe. When the back pressure at the outlet of the jet pump is large, the mixed fluid in the centrifugal pump will flow out of the jet pump through the fracture and the overflow pipe through the jet pump, thereby preventing the jet pump from backflowing out of the suction port; when the centrifugal pump stops working, the residual liquid inside the jet pump is discharged through the fracture and the overflow pipe, and there is no need to frequently start and stop the centrifugal pump, thereby extending the working life of the centrifugal pump.

Description

Technical Field

[0001] The invention belongs to the technical field of jet pumps, and in particular relates to a high-efficiency jet pump with backflow prevention. Background Art

[0002] A jet pump is a mechanical device that uses the turbulent diffusion of a jet to eject a relatively low-pressure fluid. Two fluids mix within the jet pump, exchanging mass and energy. The mixed fluid is then pressurized and discharged from the jet pump outlet. Jet pumps feature a simple structure, easy processing, good sealing, no moving parts, and ease of maintenance. They are widely used in industries such as agriculture, animal husbandry, fishery, hydropower, and environmental protection.

[0003] The low energy transfer efficiency of jet pumps is the main factor hindering their wider application. Due to the high outlet back pressure, jet pumps are prone to backflow in the throat and diffuser. During experiments or work, jet pumps need to use centrifugal pumps to pressurize the working fluid. However, the frequent start and stop of centrifugal pumps will seriously shorten the life of centrifugal pumps and have a significant impact on the working efficiency and energy consumption of centrifugal pumps. Therefore, it is necessary to improve the working efficiency of jet pumps and extend the working life of centrifugal pumps. Summary of the Invention

[0004] In view of the above problems, the present invention provides a high-efficiency jet pump with anti-backflow, which adopts the following technical solutions:

[0005] A backflow-proof and high-efficiency jet pump comprises a liquid inlet pipe, a suction chamber, a nozzle, a throat pipe, a diffuser pipe, an overflow pipe and a valve;

[0006] The inlet of the liquid inlet pipe is connected to the water outlet of the centrifugal pump, the nozzle is arranged at the outlet of the liquid inlet pipe, the suction chamber surrounds the outside of the liquid inlet pipe, the outer wall of the outlet end of the liquid inlet pipe is fixedly connected to the inner wall of the suction chamber, and the suction chamber has a sucked flow channel;

[0007] One end of the suction chamber close to the outlet of the liquid inlet pipe is fixedly connected to the throat pipe, a fluid channel is defined in the middle of the throat pipe, and a cavity is defined between the inner and outer walls of the throat pipe;

[0008] The outlet of the sucked flow channel and the outlet of the nozzle are both connected to the inlet of the fluid channel, the inlet of the diffuser is connected to the outlet of the fluid channel, and the valve is arranged in the diffuser; the inner wall of the throat pipe is provided with a fracture in the middle position of the fluid channel, the outer wall of the throat pipe is provided with an overflow port at one end close to the diffuser, and one end of the overflow pipe is connected to the overflow port.

[0009] Furthermore, the inlet of the sucked flow channel is located at one end of the suction chamber close to the inlet of the liquid inlet pipe, and the outlet of the sucked flow channel is arranged at one end of the suction chamber close to the outlet of the liquid inlet pipe.

[0010] Furthermore, the suction chamber is annular, and an isolation cavity is provided between the inner wall surface of the suction chamber and the outer wall surface of the liquid inlet pipe.

[0011] Furthermore, the length d of the fracture is determined according to the length D of the throat pipe, wherein d=0.1D~0.3D.

[0012] Furthermore, the length L of the overflow pipe is determined according to the length d of the fracture, wherein L=1d~3d.

[0013] Furthermore, the wall thickness h of the throat pipe is determined according to the distance H between the outer wall surface of the suction chamber and the inner wall surface of the throat pipe, wherein h=0.25H~0.75H.

[0014] Furthermore, the liquid inlet pipe is provided with a tapered section upstream of the nozzle, and the cross-sectional area of ​​the tapered section gradually decreases from the inlet to the outlet.

[0015] Furthermore, the inner wall surface and the outer wall surface at the outlet of the suction chamber are both configured as tapered surfaces, so that the cross-sectional area at the outlet of the sucked flow channel is larger than the cross-sectional area at the inlet of the sucked flow channel.

[0016] Furthermore, the cross-sectional area of ​​the diffusion tube gradually increases from the inlet to the outlet.

[0017] Furthermore, the jet pump further comprises a flow stabilizing tube, one end of which is connected to the outlet of the diffuser, and the other end of which is a fluid outlet.

[0018] Beneficial effects of the present invention:

[0019] 1. The jet pump of the present invention prevents the jet pump from backflowing out of the suction port through the fracture and the overflow pipe. When the back pressure at the jet pump outlet is large, the mixed fluid in the centrifugal pump will pass through the fracture and flow out of the jet pump through the overflow pipe, thereby preventing the jet pump from backflowing out of the suction port; when the centrifugal pump stops working, the residual liquid in the jet pump is discharged through the fracture and the overflow pipe, eliminating the need to frequently start and stop the centrifugal pump, thereby extending the working life of the centrifugal pump.

[0020] 2. The jet pump of the present invention discharges the air in the centrifugal pump through the fracture and the overflow pipe to prevent the air from entering the downstream pipe network. When the centrifugal pump is started, the air in the centrifugal pump will be discharged through the fracture and the overflow pipe.

[0021] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 A schematic structural diagram of a high-efficiency jet pump with backflow prevention according to an embodiment of the present invention is shown;

[0024] Figure 2 A schematic diagram showing a jet pump in working state according to an embodiment of the present invention is shown;

[0025] Figure 3 FIG. 1 is a schematic diagram showing a jet pump in a closed state according to an embodiment of the present invention.

[0026] In the figure: 1. Centrifugal pump; 2. Liquid inlet pipe; 3. Suction chamber; 4. Nozzle; 5. Throat; 6. Diffuser; 7. Overflow pipe; 8. Valve; 9. Water inlet; 10. Working flow channel; 11. Suction flow channel; 12. Fluid channel; 13. Cavity; 14. Fracture; 15. Overflow port; 16. Isolation chamber; 17. Flow stabilizing pipe; 18. Fluid outlet. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first", "second" etc. in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the application described herein. In this application, the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "center", "vertical", "horizontal", "lateral", "longitudinal" etc. are based on the directions or positional relationships shown in the accompanying drawings.

[0029] The present invention provides a high-efficiency jet pump with backflow prevention, which can maintain normal and stable operation of the jet pump under high back pressure conditions, avoid backflow of the jet pump from the suction port, improve the working efficiency of the jet pump and extend the working life of the pump.

[0030] like Figure 1 As shown, a high-efficiency jet pump with backflow prevention includes a liquid inlet pipe 2, a suction chamber 3, a nozzle 4, a throat pipe 5, a diffusion pipe 6, an overflow pipe 7 and a valve 8.

[0031] Among them, the centrifugal pump 1 has a water inlet 9 and a water outlet, the water outlet of the centrifugal pump 1 is connected to the inlet of the liquid inlet pipe 2, the liquid inlet pipe 2 has a working flow channel 10 inside, the nozzle 4 is arranged at the outlet of the liquid inlet pipe 2, the suction chamber 3 surrounds the outside of the liquid inlet pipe 2, the outer wall of the outlet end of the liquid inlet pipe 2 is fixedly connected to the inner wall of the suction chamber 3, and the suction chamber 3 has a sucked flow channel 11, the inlet of the sucked flow channel 11 is located at one end of the suction chamber 3 close to the inlet of the liquid inlet pipe 2, and the outlet of the sucked flow channel 11 is arranged at one end of the suction chamber 3 close to the outlet of the liquid inlet pipe 2.

[0032] One end of the suction chamber 3 close to the outlet of the liquid inlet pipe 2 is fixedly connected to the throat pipe 5 . A fluid channel 12 is defined in the middle of the throat pipe 5 , and a cavity 13 is defined between the inner and outer walls of the throat pipe 5 .

[0033] The outlet of the sucked flow channel 11 and the outlet of the nozzle 4 are both connected to the inlet of the fluid channel 12 in the middle of the throat pipe 5, the inlet of the diffuser 6 is connected to the outlet of the fluid channel 12, and the valve 8 is arranged in the diffuser 6; the inner wall of the throat pipe 5 is provided with a fracture 14 in the middle position of the fluid channel 12, and the outer wall of the throat pipe 5 is provided with an overflow port 15 at one end close to the diffuser 6, and one end of the overflow pipe 7 is connected to the overflow port 15.

[0034] In this embodiment, the fracture 14 on the throat pipe 5 and the overflow pipe 7 are used to prevent the jet pump from flowing back out of the suction port. When the back pressure at the jet pump outlet is large, the mixed fluid in the centrifugal pump 1 will flow out of the jet pump through the fluid channel 12, the fracture 14, and the overflow pipe 7 in sequence, thereby preventing the jet pump from flowing back out of the suction port.

[0035] In this embodiment, the air in the centrifugal pump 1 is discharged through the fracture 14 on the throat pipe 5 and the overflow pipe 7 to prevent the air from entering the downstream pipe network. When the centrifugal pump 1 is started, the air in the centrifugal pump 1 will be discharged from the jet pump through the fracture 14 and the overflow pipe 7.

[0036] In this embodiment, the residual liquid in the centrifugal pump 1 is discharged through the fracture 14 and the overflow pipe 7. When the centrifugal pump 1 stops working, the residual liquid inside the jet pump can be discharged through the fracture 14 and the overflow pipe 7, reducing the damage to the centrifugal pump 1 caused by the residual liquid.

[0037] For example, the suction chamber 3 is annular, and an isolation cavity 16 is provided between the inner wall of the suction chamber 3 and the outer wall of the liquid inlet pipe 2 . The isolation cavity 16 separates the sucked flow channel 11 in the suction chamber 3 from the working flow channel 10 in the liquid inlet pipe 2 .

[0038] For example, the length d of the fracture 14 is determined according to the length D of the throat 5 , for example, d=0.1D to 0.3D. Preferably, it is found through experiments that when d=0.15D, the working efficiency of the jet pump is the highest.

[0039] For example, the length L of the overflow pipe 7 is determined according to the length d of the fracture 14 , for example, L=1d~3d. Preferably, through experiments, it is found that when L=1.5d, the fluid in the jet pump can flow out of the overflow pipe 7 with the highest efficiency.

[0040] For example, the wall thickness of the throat pipe 5 (the distance between the inner wall and the outer wall of the throat pipe 5) h is determined according to the distance H between the outer wall surface of the suction chamber 3 and the inner wall surface of the throat pipe 5, for example, h = 0.25H ~ 0.75H. Preferably, it can be obtained through experiments that when h = 0.5H, the working efficiency of the jet pump is the highest.

[0041] For example, the liquid inlet pipe 2 is provided with a tapered section upstream of the nozzle 4, and the cross-sectional area of ​​the tapered section gradually decreases from the inlet to the outlet. By providing the tapered section, the flow resistance of the working fluid in the liquid inlet pipe 2 is reduced and the flow rate of the working fluid is increased.

[0042] For example, the inner wall and outer wall at the outlet of the suction chamber 3 are both configured as tapered surfaces, so that the cross-sectional area at the outlet of the sucked flow channel 11 is larger than the cross-sectional area at the inlet of the sucked flow channel 11 .

[0043] For example, the cross-sectional area of ​​the diffuser 6 gradually increases from the inlet to the outlet, thereby increasing the flow rate of the working fluid and reducing the fluid flow rate.

[0044] For example, the jet pump further includes a flow stabilizing tube 17 , one end of which is connected to the outlet of the diffuser 6 , and the other end of which is the fluid outlet 18 .

[0045] The working principle of the jet pump of the present invention is as follows: Figure 2As shown, when the centrifugal pump 1 starts working, the valve 8 is opened, and the working fluid enters from the water inlet 9 of the centrifugal pump 1. Through the pressurization of the centrifugal pump 1, the working fluid will pass through the working flow channel 10 and the nozzle 4 at a faster speed, forming a negative pressure at the nozzle 4, and the sucked fluid enters from the sucked flow channel 11, mixes with the working fluid, and passes through the throat pipe 5. The working fluid will pass through the diffuser 6, the flow stabilizing tube 17 and the fluid outlet 18 in sequence.

[0046] like Figure 3 As shown, when the jet pump is not needed to work, the centrifugal pump 1 is not stopped, and the valve 8 is closed. Since the fluid in the jet pump cannot pass through the valve 8, it will flow through the fracture 14 and out of the overflow pipe 7.

[0047] In this embodiment, whether the jet pump is in working state is realized by opening and closing the valve 8. When the valve 8 is opened, the working fluid will drive the sucked fluid to flow out of the jet pump through the throat pipe 5, the diffuser 6 and the voltage-stabilizing tube. The fluid flow path is consistent with the flow path of the traditional jet pump. When flowing through the throat pipe 5, due to the presence of the fracture 14, a vortex is formed at the fracture 14 and the working fluid in the cavity 13 inside the throat pipe 5. The fluid will reduce the wear with the inner wall of the throat pipe 5, thereby improving the energy transfer efficiency of the jet pump and further improving the working efficiency of the jet pump.

[0048] When the valve 8 is closed, since the working fluid cannot enter the pressure-stabilizing tube through the diffuser 6, the working fluid will drive the sucked fluid to flow out of the overflow pipe 7 through the fracture 14. There is no need to frequently start and stop the centrifugal pump 1, which extends the service life of the centrifugal pump 1.

[0049] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-efficiency jet pump with backflow prevention, characterized in that: It includes a liquid inlet pipe (2), a suction chamber (3), a nozzle (4), a throat pipe (5), a diffusion pipe (6), an overflow pipe (7) and a valve (8); The inlet of the liquid inlet pipe (2) is connected to the water outlet of the centrifugal pump (1), the nozzle (4) is arranged at the outlet of the liquid inlet pipe (2), the suction chamber (3) surrounds the outside of the liquid inlet pipe (2), the outer wall of the outlet end of the liquid inlet pipe (2) is fixedly connected to the inner wall of the suction chamber (3), and the suction chamber (3) has a sucked flow channel (11); One end of the suction chamber (3) close to the outlet of the liquid inlet pipe (2) is fixedly connected to the throat pipe (5); a fluid channel (12) is provided in the middle of the throat pipe (5); and a cavity (13) is provided between the inner wall and the outer wall of the throat pipe (5); The outlet of the sucked flow channel (11) and the outlet of the nozzle (4) are both connected to the inlet of the fluid channel (12), the inlet of the diffuser (6) is connected to the outlet of the fluid channel (12), and the valve (8) is arranged in the diffuser (6); the inner wall of the throat pipe (5) is provided with a fracture (14) at a middle position of the fluid channel (12), the outer wall of the throat pipe (5) is provided with an overflow port (15) at one end close to the diffuser (6), and one end of the overflow pipe (7) is connected to the overflow port (15).

2. The anti-backflow high-efficiency jet pump according to claim 1, characterized in that: The inlet of the sucked flow channel (11) is located at one end of the suction chamber (3) close to the inlet of the liquid inlet pipe (2), and the outlet of the sucked flow channel (11) is arranged at one end of the suction chamber (3) close to the outlet of the liquid inlet pipe (2).

3. The anti-backflow high-efficiency jet pump according to claim 1, characterized in that: The suction chamber (3) is annular, and an isolation cavity (16) is provided between the inner wall surface of the suction chamber (3) and the outer wall surface of the liquid inlet pipe (2).

4. The anti-backflow high-efficiency jet pump according to claim 1, characterized in that: The length d of the fracture (14) is determined according to the length D of the throat (5), wherein d=0.1D-0.3D.

5. The anti-backflow high-efficiency jet pump according to claim 1, characterized in that: The length L of the overflow pipe (7) is determined according to the length d of the fracture (14), wherein L=1d-3d.

6. The anti-backflow high-efficiency jet pump according to claim 1, characterized in that: The wall thickness h of the throat pipe (5) is determined according to the distance H between the outer wall surface of the suction chamber (3) and the inner wall surface of the throat pipe (5), wherein h=0.25H~0.75H.

7. The anti-backflow high-efficiency jet pump according to claim 1, characterized in that: The liquid inlet pipe (2) is provided with a tapered section upstream of the nozzle (4), and the cross-sectional area of ​​the tapered section gradually decreases from the inlet to the outlet.

8. The anti-backflow high-efficiency jet pump according to claim 1, characterized in that: The inner wall surface and the outer wall surface at the outlet of the suction chamber (3) are both configured as tapered surfaces, so that the cross-sectional area at the outlet of the sucked flow channel (11) is larger than the cross-sectional area at the inlet of the sucked flow channel (11).

9. The anti-backflow high-efficiency jet pump according to claim 1, characterized in that: The cross-sectional area of ​​the diffusion tube (6) gradually increases from the inlet to the outlet.

10. The anti-backflow high-efficiency jet pump according to any one of claims 1 to 9, characterized in that: The jet pump further comprises a flow stabilizing tube (17), one end of which is connected to the outlet of the diffusion tube (6), and the other end of which is a fluid outlet (18).

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