Anti-backflow high-efficiency jet pump

Abstract

The invention belongs to the technical field of jet pumps, and discloses an anti-backflow high-efficiency jet pump which comprises a liquid inlet pipe, a suction chamber, a nozzle, a throat pipe, a diffusion pipe, 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 close to one end of the diffusion pipe, and one end of the overflow pipe is communicated with the overflow port. According to the jet pump, backflow of the jet pump is prevented through the fracture and the overflow pipe, when the back pressure of an outlet of the jet pump is large, mixed fluid in the centrifugal pump can flow out of the jet pump through the fracture and the overflow pipe, and therefore the situation that the jet pump flows back and flows out of the sucked opening is prevented; when the centrifugal pump stops working, residual liquid in the jet pump is discharged through the fracture and the overflow pipe, the centrifugal pump does not need to be started and stopped frequently, and the service life of the centrifugal pump is prolonged.

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] The jet pump is a mechanical device that uses the jet turbulence diffusion effect to eject a relatively low-pressure fluid. The two fluids are mixed in the jet pump to exchange mass and energy. The mixed fluid is pressurized and discharged from the jet pump outlet. The jet pump has the characteristics of simple structure, easy processing, good sealing, no moving parts and easy maintenance. It is widely used in agriculture, animal husbandry, fishery, hydropower, environmental protection and other industries.

[0003] The low energy transfer efficiency of the jet pump is the main factor hindering its wider application. Due to the high outlet back pressure, the jet pump is prone to backflow at the throat and diffuser. During experiments or work, the jet pump needs to pressurize the working fluid through a centrifugal pump, and the frequent start and stop of the centrifugal pump will seriously reduce the life of the centrifugal pump, and at the same time have a great impact on the working efficiency and energy consumption of the centrifugal pump. Therefore, it is necessary to improve the working efficiency of the jet pump and extend the working life of the centrifugal pump. 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 high-efficiency jet pump comprises a liquid inlet pipe, a suction chamber, a nozzle, a throat pipe, a diffusion 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 provided in the middle of the throat pipe, and a cavity is provided between the inner wall and the outer wall 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 is provided with a break in the middle position of the fluid channel, the outer wall of the throat 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, 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] Further, the wall thickness h of the throat is determined according to the distance H between the outer wall surface of the suction chamber and the inner wall surface of the throat, 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 relatively large, the mixed fluid in the centrifugal pump will flow out of the jet pump through the fracture and 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, and there is no 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 partly become obvious from the description, or be understood by implementing 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 briefly introduces 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 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 a working state according to an embodiment of the present invention is shown;

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

[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. sucked 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] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0028] It should be noted that the terms "first", "second" etc. in the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged in appropriate circumstances, so that the embodiments of the present application described here. In the present application, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "middle", "vertical", "horizontal", "lateral", "longitudinal" etc. are based on the orientation or positional relationship 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 flowing out of 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 backflow-proof and high-efficiency jet pump comprises 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 . A cavity 13 is defined between the inner wall and the outer wall 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 break 14 in the middle 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.

[0034] In this embodiment, the break 14 on the throat 5 and the overflow pipe 7 are used to prevent the jet pump from flowing back from 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 break 14, and the overflow pipe 7 in sequence, thereby preventing the jet pump from flowing back from the suction port.

[0035] In this embodiment, the air in the centrifugal pump 1 is discharged through the break 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 break 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, thereby reducing the damage of the residual liquid to the centrifugal pump 1.

[0037] For example, 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 . 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 break 14 is determined according to the length D of the throat 5, for example, d=0.1D-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, it is found through experiments 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 5 (the distance between the inner wall and the outer wall of the throat 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 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 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 .

[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 a 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 to work, 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 channel 10 and the nozzle 4 at a faster speed, and a negative pressure will be formed at the nozzle 4. The sucked fluid enters from the sucked channel 11, mixes with the working fluid and passes through the throat 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 flow out from the overflow pipe 7.

[0047] In this embodiment, whether the jet pump is in a 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 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 5, due to the existence of the fracture 14, a vortex is formed at the fracture 14 and the working fluid in the cavity 13 inside the throat 5. The fluid will reduce the wear with the inner wall of the throat 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 voltage regulator tube through the diffuser 6, the working fluid will drive the sucked fluid to flow out of the overflow pipe 7 through the break 14. There is no need to frequently start and stop the centrifugal pump 1, thereby extending the working 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 substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions 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 comprises 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); the valve (8) is arranged in the diffuser (6); the inner wall of the throat pipe (5) is provided with a break (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 in shape, 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 break (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 (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 (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 conical 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 diffuser (6), and the other end of which is a fluid outlet (18).

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