Sealing-free radial liquid turbine pump

Abstract

A sealing-free radial liquid turbine pump is composed of a single-stage high-speed centrifugal pump and a liquid turbine driving device. The liquid turbine driving device is composed of a volute, a liquid turbine pump shaft, a flow guide shell located in an inner cavity of the volute of the liquid turbine driving device, a liquid turbine located in the flow guide shell and connected with the right end of the liquid turbine shaft, a liquid turbine nut located in the flow guide shell and connected with the right end of the liquid turbine, and an anti-channeling shaft sleeve located on the left side of the liquid turbine. The flow guide shell is designed in a modularized mode, structural parameters of the liquid turbine rotor assembly are convenient to replace, the application range of the device is expanded, the anti-channeling shaft sleeve and the liquid turbine driving device rear cover plate form a labyrinth structure, and the anti-channeling shaft sleeve and the liquid turbine driving device rear cover plate form a labyrinth structure. High pressure in the liquid turbine driving device is prevented from being transmitted to the rear pump cavity of the centrifugal pump to affect internal flow of the centrifugal pump, a sealing structure is not needed between the high-speed centrifugal pump and the liquid turbine driving device, and the problem of leakage possibly caused by the high pressure in the high-speed centrifugal pump is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of fluid machinery, in particular to a seal-free radial liquid turbine pump. Background Art

[0002] As a fluid boosting device, centrifugal pumps are widely used in process industries such as petrochemicals. They can effectively boost the pressure of fluids to achieve the purpose of conveying fluids. However, for existing centrifugal pumps, due to the existence of motor drive devices, the size of the whole machine is large, the transportation cost is high, and it is difficult to install in occasions with small installation space. For high-speed centrifugal pumps, the internal fluid pressure is high, the sealing is difficult, and the leakage problem is difficult to avoid. At the same time, the design and development of the matching high-speed motor is difficult. The conventional practice is to increase the speed of the low-speed motor through a gear speed increaser, but the use of a speed increaser has an efficiency conversion problem, which affects the overall efficiency of the centrifugal pump.

[0003] Therefore, a new type of seal-free radial hydraulic turbine pump is needed, which can not only reduce the overall size of the centrifugal pump, but also solve the internal leakage problem of the centrifugal pump, and avoid the efficiency conversion problem existing in the gear speed increaser. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the above-mentioned background technology and provide a seal-free radial liquid turbine pump, which should be able to reduce the overall size of the centrifugal pump, solve the internal leakage problem of the centrifugal pump, and avoid the efficiency conversion problem existing in the use of a gear speed increaser.

[0005] The technical solution of the present invention is: A seal-free radial liquid turbine pump, the device comprises a liquid turbine drive device volute, a liquid turbine pump shaft, a guide shell fixedly positioned in the inner cavity of the liquid turbine drive device volute, a liquid turbine rotatably positioned in the guide shell and connected to the right end of the liquid turbine pump shaft, a liquid turbine nut rotatably positioned in the guide shell and connected to the right end of the liquid turbine, a shaft sleeve rotatably positioned on the left side of the liquid turbine, a liquid turbine drive device rear cover fixedly positioned on the back of the volute, a centrifugal pump volute, a second guide shell fixed in the inner cavity of the high-speed centrifugal pump volute, an impeller rotatably positioned in the second guide shell and connected to the left end of the liquid turbine pump shaft, an inducer rotatably positioned in the second guide shell and connected to the left end of the impeller, a centrifugal pump rear cover fixedly positioned on the back of the centrifugal pump volute, and a liquid turbine pump housing fixedly positioned at the right end of the centrifugal pump rear cover; a shell wall of the guide shell is provided with a plurality of circumferentially distributed spray holes, the spray holes connecting the inner cavity of the volute with the inner cavity of the guide shell.

[0006] Preferably, the central axis of the volute, the central axis of the guide casing, the rotation axis of the impeller, the rotation axis of the inducer, and the rotation axis of the turbine shaft are coaxially arranged.

[0007] Preferably, the shaft sleeve is an anti-cross-pressure shaft sleeve, and a sawtooth groove is provided on the outer periphery of the shaft sleeve along the axial direction of the liquid turbine pump shaft, forming a maze structure with the fixed rear cover plate of the liquid turbine drive device.

[0008] Preferably, the helix angle of the volute inlet section of the liquid turbine drive device is connected to the outer circumferential surface of the volute, and the outlet section of the volute is connected to the right end surface of the volute.

[0009] Preferably, the helix angle is calculated using the following formula: in, is the helix angle, is the axial velocity of the liquid turbine outlet, is the circumferential velocity at the outlet of the liquid turbine.

[0010] Preferably, the cross-section of the volute inlet section of the liquid turbine drive device is circular, and the cross-section gradually decreases along the flow direction of the working medium.

[0011] Preferably, a nozzle is provided on the guide shell, and the nozzle is installed in each spray hole through a threaded structure, and the axis of the nozzle maintains a certain angle with the rotation axis of the liquid turbine.

[0012] Preferably, the design parameters of the nozzle are calculated using the following formula: in, is the nozzle diameter, is the inlet flow rate, is the flow coefficient, It is the nozzle working pressure.

[0013] Preferably, the right end face of the guide shell is provided with an extension section extending into the volute outlet section, and a sealing structure is provided between the outer circumferential surface of the extension section and the inner wall of the volute, and the sealing structure includes a groove arranged on the outer circumferential surface of the extension section and a sealing ring arranged in the groove.

[0014] Preferably, the left end surface of the second guide shell is provided with a second extension section extending into the outlet section of the centrifugal pump volute, and the inducer is arranged in the second extension section.

[0015] The beneficial effects of the present invention are: 1. The nozzle of the present invention is a replaceable structure, and a suitable nozzle can be selected according to the speed working conditions of the centrifugal pump.

[0016] 2. The anti-cross-pressure sleeve of the present invention is provided with a serrated groove along the axial direction of the liquid turbine on the periphery, forming a maze structure with the fixed rear cover plate of the liquid turbine drive device. Before the high-pressure working fluid in the liquid turbine drive device is transmitted to the rear chamber of the centrifugal pump, the fluid pressure can be reduced, thereby preventing the high pressure in the liquid turbine drive device from being transmitted to the rear pump chamber of the centrifugal pump and affecting the internal flow of the centrifugal pump.

[0017] 3. The high-speed centrifugal pump of the present invention and its driving device do not need to be sealed, thus avoiding the leakage problem caused by the high internal pressure and high sealing difficulty of the high-speed centrifugal pump.

[0018] 4. The present invention can reduce the size of the high-speed centrifugal pump, making the centrifugal pump structure more compact and easier to install, while reducing transportation costs.

[0019] 5. The guide casing of the present invention adopts a modular design, which can realize the replacement of structural parameters of rotor components such as impellers, liquid turbines, and inducers without changing the overall structure of the volute, thereby expanding the application scope of a single radial liquid turbine pump device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a main structural schematic diagram of the present invention.

[0021] Figure 2 It is a schematic diagram of the cross-sectional structure of the volute of the liquid turbine drive device in the present invention.

[0022] Figure 3 It is a left-side structural schematic diagram of the guide shell and the liquid turbine of the liquid turbine driving device in the present invention.

[0023] Figure 4 It is a schematic diagram of the main structure of the guide shell of the liquid turbine drive device in the present invention.

[0024] Figure 5 It is a schematic diagram of the cross-sectional structure of the anti-sequential pressure sleeve in the present invention.

[0025] Figure 6 It is a schematic diagram of the main structure of the liquid turbine and the liquid turbine nut in the present invention.

[0026] In the figure: 1. volute of liquid turbine drive device; 1.1. inlet section of volute of liquid turbine drive device; 1.2. outlet section; 2. liquid turbine pump shaft; 3. guide shell; 3.1. spray hole; 3.2. second extension section; 3.3. groove; 3.4. sealing ring; 4. liquid turbine; 5. liquid turbine nut; 6. bushing; 7. rear cover of liquid turbine drive device; 8. volute of centrifugal pump; 9. second guide shell; 10. impeller; 11. inducer; 12. rear cover of centrifugal pump; 13. liquid turbine pump housing; 14. nozzle. DETAILED DESCRIPTION

[0027] The traditional centrifugal pump includes a pump shaft, a volute, and an impeller. The impeller is set in the inner cavity of the volute. The pump shaft is fixed to the impeller so that it can rotate with the impeller. The pump shaft is connected to the motor unit through a coupling. The principle of the traditional centrifugal pump is: the high-pressure fluid flows in from the inlet section, and the motor unit drives the impeller through the coupling to work on the fluid, converting mechanical energy into pressure energy of the fluid, and finally flowing out from the outlet section to achieve the purpose of pressurizing the fluid.

[0028] The present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not limited to the following embodiments.

[0029] like Figure 1-6 As shown, a seal-free radial liquid turbine pump comprises a liquid turbine drive device volute 1, a liquid turbine pump shaft 2, a guide shell 3 fixedly positioned in the inner cavity of the liquid turbine drive device volute, a liquid turbine 4 rotatably positioned in the guide shell and connected to the right end of the liquid turbine shaft, a liquid turbine nut 5 rotatably positioned in the guide shell and connected to the right end of the liquid turbine, an anti-cross-pressure sleeve 6 rotatably positioned on the left side of the liquid turbine, a liquid turbine drive device rear cover 7 fixedly positioned on the back of the volute, a centrifugal pump volute 8, a guide shell 9 fixed in the inner cavity of the high-speed centrifugal pump volute, an impeller 10 rotatably positioned in the guide shell and connected to the left end of the liquid turbine pump shaft, an inducer 11 rotatably positioned in the guide shell and connected to the left end of the impeller, a centrifugal pump rear cover 12 fixedly positioned on the back of the centrifugal pump volute, and a liquid turbine pump housing 13 fixedly positioned at the right end of the centrifugal pump rear cover. The working medium in the liquid turbine drive device flows in sequence along the volute inlet section, the volute inner cavity, the liquid turbine in the guide casing inner cavity, and the volute outlet section, and then drives the liquid turbine pump shaft 2 to rotate, further driving the impeller 10 and the inducer 11 to rotate, so that the centrifugal pump works.

[0030] The inlet section 1.1 of the volute of the hydraulic turbine drive device is connected to the outer circumferential surface of the volute, and the outlet section 1.2 of the volute is connected to the right end surface of the volute. The cross section of the inlet section is circular, and the cross section gradually decreases along the flow direction of the working medium. The volute is calculated using the following formula: in, is the diameter of the volute base circle, is the diameter of the outlet section.

[0031] The inlet section of the volute is connected to the outer circumferential surface of the volute at a certain helix angle, so that the working fluid can better transition from the inlet section to the inner cavity of the volute. The helix angle is the angle between the tangent of the central axis of the inlet section (the central axis is the helix) and the tangent of the base circle of the volute. In order to allow the working fluid to enter the volute without impact, the liquid flow angle of the absolute velocity at the outlet of the liquid turbine is used as the helix angle, and the following formula is used for calculation: in, is the helix angle, is the axial velocity of the liquid turbine outlet, is the circumferential velocity at the outlet of the liquid turbine.

[0032] The guide housing of the liquid turbine drive device is fixed in the inner cavity of the volute, and a plurality of spray holes 3.1 are arranged on the shell wall of the guide housing, and the two ends of the spray holes are respectively located on the outer circumferential surface of the guide housing and the inner wall of the guide housing, and the spray holes connect the inner cavity of the volute and the inner cavity of the guide housing, and are distributed in a circumference, and each spray hole is installed with a nozzle 14 through a threaded structure. The right end surface of the guide housing is provided with an extension section 3.2 protruding to the right, and the extension section extends into the outlet section of the volute, and a sealing structure is provided between the outer circumferential surface of the extension section and the inner wall of the volute. The sealing structure includes a groove 3.3 arranged on the outer circumferential surface of the extension section and a sealing ring 3.4 arranged in the groove.

[0033] The nozzle and the spray hole are connected by a threaded structure to facilitate the use of nozzles with different cross-sectional areas under different working conditions, thereby increasing the speed adaptability range of the liquid turbine drive device. The axis of the nozzle has a certain angle with the rotation axis of the liquid turbine, guiding the working fluid to spray into the liquid turbine at a certain angle, thereby reducing the energy loss caused by the splash of the working fluid due to the unreasonable incident angle of the working fluid. The end of the nozzle extends into the inner cavity of the guide shell and maintains a certain distance from the liquid turbine to avoid wear caused by mutual interference between the nozzle and the liquid turbine. The design parameters of the nozzle are calculated using the following formula: in, is the nozzle diameter, is the inlet flow rate, is the flow coefficient, It is the nozzle working pressure.

[0034] The shaft sleeve is an anti-cross-pressure sleeve, and a serrated groove 6.1 is provided on the outer periphery of the shaft sleeve along the axial direction of the liquid turbine, forming a maze structure with the fixed rear cover plate of the liquid turbine drive device. Before the high-pressure working medium in the liquid turbine drive device is transmitted to the rear chamber of the centrifugal pump, the fluid pressure can be reduced to prevent the high pressure in the liquid turbine drive device from being transmitted to the rear pump chamber of the centrifugal pump and affecting the internal flow of the centrifugal pump. No high-strength sealing is required between the high-speed centrifugal pump and its drive device.

[0035] A sealing structure is provided between the outer circumferential surface of the extended section of the liquid turbine drive device and the inner wall of the volute.

[0036] The liquid turbine is rotatably positioned in the guide shell, the right end of the liquid turbine pump shaft extends into the inner cavity of the volute of the liquid turbine driving device and is fixed to the liquid turbine, and the liquid turbine nut is arranged on the right end surface of the liquid turbine and is coaxially fixed to the liquid turbine.

[0037] The central axis of the volute, the central axis of the guide casing, the rotation axis of the liquid turbine, and the rotation axis of the liquid turbine pump shaft are coaxially arranged.

[0038] The present invention proposes a novel centrifugal pump driving device: in order to stabilize the flow state of the working medium before entering the liquid turbine, an inlet section of a certain length is set before the working medium enters the inner cavity of the volute of the driving device; a replaceable nozzle is installed on the guide shell of the driving device, and the high-pressure fluid is introduced into the driving liquid turbine through the nozzle port, and the liquid turbine drives the pump shaft to rotate, thereby driving the centrifugal pump impeller to rotate; an anti-cross-pressure sleeve is provided on the back of the liquid turbine, and a serrated groove is provided on the outer periphery of the sleeve along the axial direction of the liquid turbine, forming a maze structure with the fixed rear cover plate of the liquid turbine driving device, so that the fluid pressure can be reduced before the high-pressure working medium in the liquid turbine driving device is transmitted to the rear cavity of the centrifugal pump, thereby preventing the high pressure in the liquid turbine driving device from being transmitted to the rear pump cavity of the centrifugal pump and affecting the internal flow of the centrifugal pump.

[0039] The above are only specific implementation cases of the present invention. Obviously, the present invention is not limited to the above implementation cases, and there may be many similar changes or modifications. Ordinary technicians in this field can simply directly or indirectly associate similar changes or modifications from the contents disclosed in the present invention. Therefore, these changes or modifications are still within the scope of protection of the present invention.

Claims

1. A seal-free radial liquid turbine pump, comprising a liquid turbine drive device volute (1), a liquid turbine pump shaft (2), a guide shell (3) fixedly positioned in the inner cavity of the liquid turbine drive device volute (1), a liquid turbine (4) rotatably positioned in the guide shell (3) and connected to the right end of the liquid turbine pump shaft (2), and a liquid turbine nut (5) rotatably positioned in the guide shell (3) and connected to the right end of the liquid turbine (4), characterized in that: It also includes a shaft sleeve (6) rotatably positioned on the left side of the liquid turbine (4), a liquid turbine drive device rear cover (7) fixedly positioned on the back side of the volute, a centrifugal pump volute (8), a second guide shell (9) fixed in the inner cavity of the high-speed centrifugal pump volute (8), an impeller (10) rotatably positioned in the second guide shell (9) and connected to the left end of the liquid turbine pump shaft (2), an inducer (11) rotatably positioned in the second guide shell (9) and connected to the left end of the impeller (10), a centrifugal pump rear cover (12) fixedly positioned on the back side of the centrifugal pump volute (8), and a liquid turbine pump housing (13) fixedly positioned at the right end of the centrifugal pump rear cover (12); a shell wall of the guide shell (3) is provided with a plurality of circumferentially distributed spray holes (3.1), the spray holes (3.1) communicating the inner cavity of the volute with the inner cavity of the guide shell (3).

2. A seal-free radial hydraulic turbine pump according to claim 1, characterized in that: The central axis of the volute, the central axis of the guide casing, the rotation axis of the impeller, the rotation axis of the inducer, and the rotation axis of the turbine shaft are coaxially arranged.

3. The seal-free radial hydraulic turbine pump according to claim 1, characterized in that: The shaft sleeve (6) is an anti-cross-pressure shaft sleeve, and a sawtooth groove (6.1) is provided on the outer periphery of the shaft sleeve (6) along the axial direction of the liquid turbine pump shaft (2), forming a labyrinth structure with a fixed liquid turbine drive device rear cover plate (7).

4. The seal-free radial hydraulic turbine pump according to claim 1, characterized in that: The helical angle of the volute inlet section (1.1) of the liquid turbine drive device is connected to the outer circumferential surface of the volute, and the volute outlet section (1.2) is connected to the right end surface of the volute.

5. The seal-free radial hydraulic turbine pump according to claim 4, characterized in that: The helix angle is calculated using the following formula: in, is the helix angle, is the axial velocity of the liquid turbine outlet, is the circumferential velocity at the outlet of the liquid turbine.

6. The seal-free radial hydraulic turbine pump according to claim 4, characterized in that: The cross section of the volute inlet section (1.1) of the liquid turbine drive device is circular, and the cross section gradually decreases along the flow direction of the working medium.

7. The seal-free radial hydraulic turbine pump according to claim 1, characterized in that: The guide shell (3) is provided with a nozzle (14), which is installed in each spray hole (3.1) through a threaded structure, and the axis of the nozzle (14) maintains a certain angle with the rotation axis of the liquid turbine.

8. The seal-free radial hydraulic turbine pump according to claim 7, characterized in that: The design parameters of the nozzle are calculated using the following formula: in, is the nozzle diameter, is the inlet flow rate, is the flow coefficient, It is the nozzle working pressure.

9. The seal-free radial hydraulic turbine pump according to claim 1, characterized in that: The right end face of the guide casing (3) is provided with an extension section extending into the volute outlet section, and a sealing structure is provided between the outer circumferential surface of the extension section and the inner wall of the volute, the sealing structure comprising a groove (3.3) provided on the outer circumferential surface of the extension section and a sealing ring (3.4) provided in the groove.

10. The seal-free radial hydraulic turbine pump according to claim 1, characterized in that: The left end surface of the second guide casing (9) is provided with a second extension section (3.2) extending into the outlet section of the centrifugal pump volute (8), and the inducer (11) is arranged in the second extension section (3.2).

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