Shaft-seal-free pump and liquid flow dividing and leakage preventing method

Abstract

The invention provides a shaft-seal-free pump and a liquid flow dividing and leakage preventing method. The shaft-seal-free pump comprises a pump body, a backflow pipe is arranged on the pump body, an impeller rear opening ring is lengthened or a lengthened sleeve is assembled on the inner side of the rear opening ring, the lengthened sleeve is matched with a pump cover rear end fixing ring to form a tail end gap, and a thread seal or a spiral blade seal is arranged at the tail end gap. And an open hole leading to the suction side or the low-pressure side is formed between the wear ring gap and the tail end gap. Through the static seal at the joint of the flow blocking sleeve and the pump cover, the seal design at the rear opening ring of the impeller and the thread seal or spiral blade seal at the tail end gap formed by matching the lengthening sleeve and the fixing ring at the rear end of the pump cover, liquid leakage is effectively prevented, the working efficiency of the pump is improved, and energy waste is reduced. Through the spiral groove and the liquid backflow system, part of liquid returns to the low-pressure position of the inlet of the pump body through the backflow pipe, recycling of the liquid is achieved, maintaining of pressure balance in the pump is facilitated, and the overall efficiency of the pump is improved.

Description

Technical Field

[0001] The invention relates to the field of pump and water turbine fluid machinery, and in particular to a shaft seal-free pump and a liquid diversion and leakage prevention method. Background Art

[0002] In the industrial field, a pump is a commonly used fluid conveying equipment. The structural technical field of the pump proposed in the Chinese invention patent application number: CN201010004111.1. It includes a pump body and a suspension arranged at the rear end of the pump body, a pump cover is arranged between the pump body and the suspension, the pump shaft penetrates through the suspension and the pump cover to enter the pump body, a seal is arranged between the pump body and the pump cover, a horizontally opened liquid inlet, an upwardly opened liquid outlet and a flow channel connecting the liquid inlet and outlet are provided on the pump body, and a guide vane is arranged on the part of the pump shaft in the pump body, and the guide vane is arranged at the slightly front end of the pump cover, at the rear end of the bend of the liquid inlet and the liquid outlet. When the liquid medium passes through the guide vane to generate a swirl in the liquid, the liquid is directly sent upward, reducing the direct contact between the guide vane and the liquid medium, so that the pump can avoid direct contact between the guide vane and the longer and harder substances during operation, and the liquid can also be directly sent out through the swirl generated by the guide vane when encountering high-concentration wood pulp.

[0003] However, the existing pumps have some shortcomings during use and still need to be improved. First, some pumps in the prior art have poor sealing and are prone to liquid leakage, which not only leads to energy waste, but also may pollute the working environment and even affect the normal operation of the equipment.

[0004] In the operation of the pump, efficiency is also a key issue. The unreasonable structural design of some traditional pumps leads to poor liquid flow, large energy loss, and inability to achieve efficient fluid delivery.

[0005] In addition, the operating stability of traditional pumps needs to be improved. The rotation of the pump shaft is unstable, which is prone to vibration and noise, which not only affects the service life of the pump, but may also have an adverse effect on the operation of the entire system. Cavitation is one of the common problems in the operation of pumps. In the prior art, some pumps are prone to cavitation due to the lack of effective exhaust measures, which damages the internal structure of the pump and reduces the performance and service life of the pump.

[0006] At the same time, traditional pumps also have shortcomings in pressure control. When the pressure in the pump is too high, the lack of timely and effective pressure relief measures may cause damage to the pump body and even cause safety accidents. In terms of optimizing liquid flow, some pumps in the prior art fail to fully consider the diversion and guidance of liquid, resulting in insufficient smoothness of liquid flow and affecting the working efficiency of the pump; therefore, we have made improvements to this and proposed a sealless pump and a liquid diversion and leakage prevention method. Summary of the invention

[0007] The purpose of the present invention is to solve the problems raised by the existing background technology. In order to achieve the above invention purpose, the present invention provides the following technical solutions: a shaft sealless pump, including a pump body, an impeller is arranged in the pump body, a baffle sleeve is arranged above the impeller, a pump cover is arranged above the pump body, and the pump cover is sleeved on the outer surface of the baffle sleeve, the front end of the pump cover cooperates with the rear mouth ring of the impeller to form a mouth ring gap, and the rear end of the baffle sleeve is a spiral groove; the spiral blade forms a gap with the rear end of the pump cover, and a hole is opened on the pump cover in the middle of the gap, one end of the return pipe is connected to the opening of the pump cover, and the other end of the return pipe is connected to the low pressure of the pump body inlet, a static seal is arranged at the connection between the baffle sleeve and the pump cover, a return pipe is opened on the pump body, the rear mouth ring of the impeller is extended or an extension sleeve is arranged on the inner side of the rear mouth ring, the extension sleeve cooperates with the rear end fixing ring of the pump cover to form a terminal gap, and a threaded seal or a spiral blade seal is arranged at the terminal gap; an opening is arranged between the mouth ring gap and the terminal gap to lead to the suction side or the low pressure side.

[0008] As a preferred technical solution of the present invention, the impeller is arranged on the pump shaft, a bearing component is arranged on the pump shaft, a rear cover body is arranged on the side of the pump body, and an L-shaped support seat is arranged below the rear cover body.

[0009] As a preferred technical solution of the present invention, an impeller nut is provided at the end of the impeller, the bearing component is provided with a bearing, a sleeve sealing ring is provided on the bearing, and the bearing and the sleeve sealing ring are both sleeved on the outer surface of the pump shaft.

[0010] As a preferred technical solution of the present invention, a shunt pipe connector is provided at the upper end of the extension sleeve, the shunt pipe connector is connected to a liquid shunt pipe, and a V-shaped cover is provided above the liquid shunt pipe.

[0011] As a preferred technical solution of the present invention, a sealing valve is arranged below the pump body, a pressure relief valve is arranged above the pump body, and an exhaust valve is arranged below the middle of the pump body.

[0012] As a preferred technical solution of the present invention, a shaft keyway is provided on the pump shaft, a leak-proof gasket is provided between the pump cover and the pump body, and a reflux chamber is connected to the end of the reflux pipe.

[0013] A method for preventing leakage of liquid from being diverted by a sealless pump comprises the following steps:

[0014] Step 1. Preparation: Ensure that all parts of the sealless pump, such as the pump body, impeller, choke sleeve, pump cover, return pipe, extension sleeve, and bearing parts, have been correctly installed and are in good condition; check whether the sealing valve, pressure relief valve, and exhaust valve are working properly, and ensure that the shaft keyway on the pump shaft and the leak-proof gasket sealing parts between the pump cover and the pump body are not damaged;

[0015] Step 2. Start the pump: Start the sealless pump and allow the impeller to start rotating driven by the pump shaft;

[0016] Step 3. Liquid diversion: During the rotation of the impeller, the liquid is transported under the action of the impeller; the liquid diversion pipe connected to the diversion pipe connector at the upper end of the extension sleeve diverts part of the liquid; the V-shaped cover above the liquid diversion pipe can play a certain protective role;

[0017] Step 4. Pump leak prevention:

[0018] Leakage prevention of mouth ring gap and end gap: the openings set between the mouth ring gap and the end gap lead to the suction side or low pressure side, so that the leaked liquid can flow back to the suction side or low pressure side through these openings, reducing the leakage;

[0019] Static seal at the connection between the choke sleeve and the pump cover: Ensure that the static seal at the connection between the choke sleeve and the pump cover is good to prevent liquid leakage from this place;

[0020] Treatment of the gap between the spiral blade and the rear end of the pump cover: A gap is formed between the spiral blade and the rear end of the pump cover, and a hole is opened on the pump cover in the middle of the gap. One end of the return pipe is connected to the hole in the pump cover, and the other end is connected to the low-pressure part of the pump body inlet; in this way, the liquid leaking into the gap can flow back to the low-pressure part of the pump body inlet through the return pipe to avoid leakage to the outside;

[0021] Step 5. Operation monitoring: During the operation of the pump, pay close attention to the working status of the sealing valve, pressure relief valve, exhaust valve, and whether there is leakage in the pump body and pump cover; at the same time, pay attention to the diversion effect of the liquid diversion pipe to ensure that the liquid can be diverted normally;

[0022] Step 6. Maintenance and care: Regularly perform maintenance on the sealless pump, check the wear of each component, and promptly replace damaged components, including the impeller nut, bearing, and sleeve seal ring; ensure the normal operation and leakage-proof performance of the pump.

[0023] As a preferred technical solution of the present invention, step 4. Pump leakage prevention, the leakage formula of the end gap is:

[0024] Where: Q1 is the end gap leakage; A1 is the area of ​​the end gap; ΔP1 is the end gap pressure difference; K1 is the end gap leakage coefficient.

[0025] As a preferred technical solution of the present invention, step 4. Pump leakage prevention, the leakage formula of the spiral blade gap is:

[0026]

[0027] Where: Q2 is the leakage of the spiral blade gap; A2 is the area of ​​the spiral blade gap; ΔP2 is the pressure difference of the spiral blade gap; K2 is the leakage coefficient of the spiral blade gap; μ(T) is the dynamic viscosity of the actual measured fluid changing with temperature, μ ref is the viscosity at standard temperature.

[0028] As a preferred technical solution of the present invention, step 4. Pump leakage prevention, the leakage amount of the mouth ring gap is:

[0029]

[0030] Where: Q3 is the leakage of the mouth ring gap; A3 is the area of ​​the mouth ring gap; ΔP3 is the pressure difference of the mouth ring gap; K3 is the leakage coefficient of the mouth ring gap; e is the turbulence intensity coefficient; V is the velocity of the fluid; μ(T) is the dynamic viscosity of the actual measured fluid changing with temperature.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: In the scheme of the present invention: through the static seal at the connection between the baffle sleeve and the pump cover, and the sealing design at the impeller rear ring, such as the threaded seal or spiral blade seal at the end gap formed by the cooperation between the extended sleeve and the rear end fixing ring of the pump cover, liquid leakage is effectively prevented, the working efficiency of the pump is improved, and energy waste is reduced.

[0032] Through the spiral groove and liquid reflux system, part of the liquid returns to the low-pressure inlet of the pump body through the reflux pipe, realizing the recycling of the liquid, helping to maintain the pressure balance in the pump and improving the overall efficiency of the pump.

[0033] The bearing components, sleeve seals and other designs on the pump shaft ensure stable rotation of the pump shaft, reduce vibration and noise, and improve the operational stability and reliability of the pump. The exhaust valve located at the bottom of the pump body can exhaust the gas in the pump to avoid cavitation and extend the service life of the pump.

[0034] The pressure relief valve on the top of the pump body can release the pressure when the pressure in the pump is too high, preventing the pump body from being damaged due to excessive pressure, thus improving the operating safety of the pump. The liquid diversion pipe and V-shaped cover on the upper end of the extension sleeve can be used to divert and guide the liquid, making the liquid flow smoother and further improving the working efficiency of the pump.

[0035] The pump has a relatively simple structural design, and the functions of each component are clear, which makes it easy to maintain and repair, reducing maintenance costs. The sealless pump can adapt to a variety of working environments and media, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the structure provided by the present invention;

[0037] Figure 2 A schematic cross-sectional view of the structure provided by the present invention;

[0038] Figure 3 This is a schematic diagram of the half-section structure provided by the present invention.

[0039] Indicated in the figure:

[0040] 1. Pump body; 2. Impeller; 201. Impeller nut; 3. choke sleeve; 4. Pump cover; 5. Static seal; 6. Reflux pipe; 7. Bearing component; 701. Bearing; 8. Pump shaft; 9. Extension sleeve; 10. Rear cover; 11. L-shaped support seat; 12. V-shaped cover; 13. Diverter pipe connector; 14. Liquid diverter pipe; 15. Sealing valve; 16. Pressure relief valve; 17. Exhaust valve; 18. Shaft keyway; 19. Leak-proof gasket; 20. Reflux chamber; 21. Shaft sleeve sealing ring. DETAILED DESCRIPTION

[0041] 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 described clearly and completely in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0042] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely represents some embodiments of the present invention. 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. It should be noted that the embodiments of the present invention and the features and technical solutions in the embodiments can be combined with each other without conflict. It should be noted that similar numbers and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0043] Example 1: Please refer to Figure 1-Figure 3A shaft sealless pump comprises a pump body 1, an impeller 2 is arranged in the pump body 1, a choke sleeve 3 is arranged above the impeller 2, a pump cover 4 is arranged above the pump body 1, and the pump cover 4 is sleeved on the outer surface of the choke sleeve 3, the front end of the pump cover 4 cooperates with the rear mouth ring of the impeller 2 to form a mouth ring gap, and the rear end of the choke sleeve 3 is a spiral groove; the spiral blade and the rear end of the pump cover 4 form a gap, the pump cover 4 in the middle of the gap is opened, one end of the return pipe 6 is connected to the opening of the pump cover 4, and the other end of the return pipe 6 is connected to the low pressure part of the inlet of the pump body 1, a static seal 5 is arranged at the connection between the choke sleeve 3 and the pump cover 4, a return pipe 6 is opened on the pump body 1, the rear mouth ring of the impeller 2 is extended or an extension sleeve 9 is assembled on the inner side of the rear mouth ring, the extension sleeve 9 cooperates with the rear end fixing ring of the pump cover 4 to form a terminal gap, and a threaded seal or a spiral blade seal is arranged at the terminal gap; an opening leading to the suction side or the low pressure side is arranged between the mouth ring gap and the terminal gap.

[0044] The impeller 2 is arranged on the pump shaft 8, the pump shaft 8 is provided with a bearing component 7, the pump cover 4 is arranged on the side of the pump body 1, and an L-shaped support seat 11 is arranged below the rear cover body 10. An impeller nut 201 is arranged at the end of the impeller 2, the bearing component 7 is provided with a bearing 701, and a sleeve seal ring 21 is arranged on the bearing 701. The bearing 701 and the sleeve seal ring 21 are both sleeved on the outer surface of the pump shaft 8.

[0045] The upper end of the extension sleeve 9 is provided with a shunt pipe connector 13, the shunt pipe connector 13 is connected to a liquid shunt pipe 14, and a V-shaped cover 12 is provided above the liquid shunt pipe 14. A sealing valve 15 is provided below the pump body 1, a pressure relief valve 16 is provided above the pump body 1, and an exhaust valve 17 is provided at the middle and lower part of the pump body 1. A shaft keyway 18 is provided on the pump shaft 8, a leakproof gasket 19 is provided between the pump cover 4 and the pump body 1, and a reflux chamber 20 is connected to the end of the reflux pipe 6.

[0046] Working principle of the sealless pump: When the pump is started, the impeller 2 starts to rotate driven by the pump shaft 8. The rotation of the impeller 2 generates centrifugal force, causing the liquid to be sucked into the pump body 1 and thrown outward at an accelerated speed.

[0047] Under the action of the impeller 2, the liquid enters the gap between the impeller 2 and the front end of the pump cover 4, and then passes through the spiral groove at the rear end of the choke sleeve 3. The spiral groove can play a certain role in guiding and reducing pressure, reducing the energy loss of the liquid.

[0048] The gap formed between the spiral blade and the rear end of the pump cover 4 and the opening on the pump cover 4 allow a portion of the liquid to flow back to the low-pressure inlet of the pump body 1 through the reflux pipe 6. This can achieve liquid circulation, improve the efficiency of the pump, and help maintain the pressure balance in the pump.

[0049] The static seal 5 provided at the connection between the choke sleeve 3 and the pump cover 4, and the threaded seal or spiral blade seal provided at the end gap formed by the extension sleeve 9 extended or assembled by the rear ring of the impeller 2 and the rear end fixing ring of the pump cover 4, can effectively prevent liquid leakage and ensure the sealing of the pump.

[0050] The opening between the mouth ring gap and the end gap leads to the suction side or low pressure side, which can balance the pressure between the two gaps and further reduce the possibility of leakage.

[0051] The impeller 2 is arranged on the pump shaft 8, and the bearing component 7 on the pump shaft 8 provides support and stability for the rotation of the impeller 2. The sleeve seal ring 21 on the bearing 701 can prevent liquid from entering the bearing 701, thereby protecting the normal operation of the bearing 701.

[0052] The liquid diverter pipe 14 connected to the diverter pipe connector 13 at the upper end of the extension sleeve 9 and the V-shaped cover 12 above can divert and guide the liquid to improve the flow efficiency of the liquid.

[0053] The sealing valve 15 below the pump body 1 can prevent liquid from leaking from the bottom of the pump body 1, and the pressure relief valve 16 above can relieve pressure when the pressure in the pump is too high to ensure the safe operation of the pump. The exhaust valve 17 below the middle can exhaust the gas in the pump to avoid cavitation.

[0054] The shaft keyway 18 on the pump shaft 8 is used to transmit torque to ensure the synchronous rotation of the pump shaft 8 and the impeller 2 and other components. The leakproof gasket 19 between the pump cover 4 and the pump body 1 can enhance the sealing between the two to prevent liquid leakage. The reflux chamber 20 connected to the end of the reflux pipe 6 can store the refluxed liquid so that it can be better re-absorbed and utilized by the pump body 1.

[0055] In general, this sealless pump achieves efficient and stable liquid transportation through reasonable structural design and sealing measures, while ensuring the sealing and safety of the pump.

[0056] Specific working process of sealless pump:

[0057] Start the pump: the motor drives the pump shaft 8 to rotate, the impeller nut 201 on the pump shaft 8 fixes the impeller 2 on the pump shaft 8, and the impeller 2 rotates together with the pump shaft 8.

[0058] Liquid suction: The rotation of impeller 2 generates centrifugal force, forming a low-pressure area inside the pump body 1, and the liquid is sucked in from the inlet of the pump body 1.

[0059] Liquid acceleration: The sucked liquid is accelerated by the impeller 2 and thrown out to the periphery of the impeller 2.

[0060] Through the mouth ring gap: After the liquid flows out of the impeller 2, it enters the mouth ring gap formed by the front end of the pump cover 4 and the rear mouth ring of the impeller 2.

[0061] Flowing through the choke sleeve 3: After passing through the mouth ring gap, the liquid enters the choke sleeve 3 above the impeller 2. The spiral groove at the rear end of the choke sleeve 3 guides and reduces the pressure on the liquid.

[0062] Part of the liquid refluxes: In the gap formed by the spiral blade and the rear end of the pump cover 4, a part of the liquid passes through the opening on the pump cover 4 in the middle of the gap and enters the reflux pipe 6. The reflux pipe 6 transports this part of the liquid to the low-pressure inlet of the pump body 1 to realize the circulation of the liquid and improve the efficiency of the pump.

[0063] Sealing and leak prevention: The static seal 5 at the connection between the choke sleeve 3 and the pump cover 4, and the thread seal or spiral blade seal at the end gap formed by the extension sleeve 9 extended or assembled by the rear ring of the impeller 2 and the rear end fixing ring of the pump cover 4 prevent liquid leakage. The opening between the ring gap and the end gap leads to the suction side or low pressure side, balancing the pressure between the two gaps and further reducing leakage.

[0064] Liquid diversion: The liquid diversion pipe 14 connected to the diversion pipe connector 13 at the upper end of the extension sleeve 9 diverts the liquid. The V-shaped cover 12 above the liquid diversion pipe 14 guides the diverted liquid to make it flow more smoothly.

[0065] Ensure safe operation: The sealing valve 15 below the pump body 1 prevents liquid from leaking from the bottom of the pump body 1, and the pressure relief valve 16 above relieves pressure when the pressure in the pump is too high to ensure safe operation of the pump. The exhaust valve 17 below the middle exhausts the gas in the pump to avoid cavitation.

[0066] Support and stability: The L-shaped support seat 11 below the rear cover body 10 on the side of the pump body 1 provides support for the pump cover 4. The bearing 701 of the bearing component 7 on the pump shaft 8 and the shaft sleeve seal 21 ensure the stable rotation of the pump shaft 8. The shaft keyway 18 on the pump shaft 8 transmits torque.

[0067] Enhanced sealing: The leakproof gasket 19 between the pump cover 4 and the pump body 1 enhances the sealing between the two to prevent liquid leakage. The reflux chamber 20 connected to the end of the reflux pipe 6 stores the refluxed liquid so that it can be better re-absorbed and utilized by the pump body 1.

[0068] Embodiment 2: A method for preventing leakage of liquid from being diverted by a sealless pump, comprising the following steps:

[0069] Step 1. Preparation: Ensure that all parts of the sealless pump, such as pump body 1, impeller 2, choke sleeve 3, pump cover 4, return pipe 6, extension sleeve 9, bearing component 7, are properly installed and in good condition; check whether the sealing valve 15, pressure relief valve 16, exhaust valve 17 are working properly, and ensure that the shaft keyway 18 on the pump shaft 8 and the leakproof gasket 19 sealing parts between the pump cover 4 and the pump body 1 are not damaged;

[0070] Step 2. Start the pump: Start the sealless pump so that the impeller 2 starts to rotate driven by the pump shaft 8;

[0071] Step 3. Liquid diversion: During the rotation of the impeller 2, the liquid is transported under the action of the impeller 2; the liquid diversion pipe 14 connected to the diversion pipe connector 13 at the upper end of the extension sleeve 9 diverts part of the liquid; the V-shaped cover 12 above the liquid diversion pipe 14 can play a certain protective role;

[0072] Step 4. Pump leak prevention:

[0073] Leakage prevention of mouth ring gap and end gap: the openings set between the mouth ring gap and the end gap lead to the suction side or low pressure side, so that the leaked liquid can flow back to the suction side or low pressure side through these openings, reducing the leakage;

[0074] Static seal 5 at the connection between the choke sleeve 3 and the pump cover 4: Ensure that the static seal 5 at the connection between the choke sleeve 3 and the pump cover 4 is good to prevent liquid leakage from this place;

[0075] Treatment of the gap between the spiral blade and the rear end of the pump cover 4: a gap is formed between the spiral blade and the rear end of the pump cover 4, a hole is opened on the pump cover 4 in the middle of the gap, one end of the reflux pipe 6 is connected to the hole on the pump cover 4, and the other end is connected to the low-pressure part of the inlet of the pump body 1; in this way, the liquid leaking into the gap can flow back to the low-pressure part of the inlet of the pump body 1 through the reflux pipe 6, avoiding leakage to the outside;

[0076] Step 5. Operation monitoring: During the operation of the pump, pay close attention to the working status of the sealing valve 15, the pressure relief valve 16, and the exhaust valve 17, as well as whether there is leakage in the pump body 1 and the pump cover 4; at the same time, pay attention to the diversion effect of the liquid diversion pipe 14 to ensure that the liquid can be diverted normally;

[0077] Step 6. Maintenance and care: Regularly perform maintenance on the sealless pump, check the wear of each component, and replace damaged components in time, including the impeller nut 201, bearing 701, and sleeve seal 21; ensure the normal operation and leakage-proof performance of the pump.

[0078] Step 4. Pump leakage prevention, the leakage formula of the end gap is:

[0079] Where: Q1 is the end gap leakage; A1 is the area of ​​the end gap; ΔP1 is the end gap pressure difference; K1 is the end gap leakage coefficient.

[0080] Step 4. Pump leakage prevention, the leakage formula of the spiral blade gap is:

[0081]

[0082] Where: Q2 is the leakage of the spiral blade gap; A2 is the area of ​​the spiral blade gap; ΔP2 is the pressure difference of the spiral blade gap; K2 is the leakage coefficient of the spiral blade gap; μ(T) is the dynamic viscosity of the actual measured fluid changing with temperature, μ ref is the viscosity at standard temperature.

[0083] Step 4. Pump leakage prevention, mouth ring gap leakage:

[0084]

[0085] Where: Q3 is the leakage of the mouth ring gap; A3 is the area of ​​the mouth ring gap; ΔP3 is the pressure difference of the mouth ring gap; K3 is the leakage coefficient of the mouth ring gap; e is the turbulence intensity coefficient; V is the velocity of the fluid; μ(T) is the dynamic viscosity of the actual measured fluid changing with temperature.

[0086] Embodiment 3: A pump without shaft seal, wherein the impeller 2 is installed in the pump body 1, the choke sleeve 3 is fixed on the inner side of the rear ring of the impeller 2, the pump cover 4 is installed on the pump body 1, the front end of the pump cover 4 cooperates with the rear ring of the impeller 2 to form a gap, the rear end of the choke ring is processed into a spiral groove or a spiral blade to form a gap at the rear end of the pump cover 4, a hole is opened on the pump cover 4 between the two gaps, one end of the return pipe 6 is connected to the hole in the pump cover 4, and the other end is connected to the low pressure part of the inlet of the pump body 1, forming a reflux, which plays the role of oblique flow of liquid, balancing axial force and improving pump efficiency. The static seal 5 is installed at the end of the choke sleeve 3 and the pump cover 4 to prevent the leakage of residual liquid.

[0087] A choke sleeve 3 completely separated from the shaft is provided at the rear side of the impeller 2. The choke sleeve 3 forms a very small gap seal with the pump cover 4. A return pipe 6 is provided between the two gaps to allow the liquid to flow to the pump inlet or the low-pressure side.

[0088] The present invention proposes a sealless pump structure, in which the rear ring of the pump impeller 2 is extended or an extension sleeve 9 is installed inside the rear ring, so that it cooperates with the rear end fixing ring of the pump cover 4 to form a small gap, and a thread seal or a spiral blade seal is set, which is called the end gap. A larger diameter opening is opened between the ring gap and the end gap to the suction side or the low pressure side, so that the liquid leaking from the high pressure area flows from the return pipe 6 to the low pressure area, instead of flowing and leaking in the direction of the shaft, achieving the effect of no need for a shaft seal, thereby saving manufacturing costs, and reducing the maintenance frequency during the operation of the pump, saving production costs.

[0089] The present invention discharges liquid from the high-pressure area to the low-pressure area through the return pipe 6, and there is no need to drill multiple balancing holes on the impeller 2, increase auxiliary blades or increase auxiliary impellers 2. This can balance the axial force and reduce the damage of these structures to the flow state, thereby improving the pump efficiency.

[0090] The structure of the present invention is simple to assemble and has strong interchangeability. It can be used on almost any pump type. It only needs to remove the original sealing form and replace the pump cover 4 on the basis of the original pump, and then install the new component mechanism to complete the pump optimization work.

[0091] During the use of the present invention, in the preparation work, the various components of the sealless pump are correctly installed and their status is checked to ensure that the sealing valve 15, the pressure relief valve 16, and the exhaust valve 17 are working normally, and the sealing components such as the shaft keyway 18 and the leak-proof gasket 19 on the pump shaft 8 are not damaged, so as to prepare for the normal operation of the pump.

[0092] After the pump is started, the impeller 2 starts to rotate driven by the pump shaft 8. During the rotation of the impeller 2, the liquid is transported. At the same time, the liquid diverter pipe 14 connected to the diverter pipe connector 13 at the upper end of the extension sleeve 9 diverts part of the liquid, and the V-shaped cover 12 above the liquid diverter pipe 14 plays a certain protective role.

[0093] Leakage prevention of mouth ring gap and end gap: Openings are set between the mouth ring gap and the end gap, leading to the suction side or low-pressure side. When leakage occurs, the leaked liquid can flow back to the suction side or low-pressure side through these openings, thereby reducing the leakage amount. The leakage amount can be calculated by the formula.

[0094] Static seal 5 at the connection between the choke sleeve 3 and the pump cover 4: Ensure that the static seal 5 at the connection between the choke sleeve 3 and the pump cover 4 is good to prevent liquid from leaking therefrom.

[0095] Treatment of the gap between the spiral blade and the rear end of the pump cover 4: A gap is formed between the spiral blade and the rear end of the pump cover 4, and a hole is opened on the pump cover 4 in the middle of the gap. One end of the reflux pipe 6 is connected to the hole in the pump cover 4, and the other end is connected to the low-pressure inlet of the pump body 1. In this way, the liquid leaking into the gap can flow back to the low-pressure inlet of the pump body 1 through the reflux pipe 6 to avoid leakage to the outside. The leakage amount can be calculated by the corresponding formula.

[0096] During the operation of the pump, pay close attention to the working conditions of the sealing valve 15, the pressure relief valve 16, and the exhaust valve 17, as well as whether there is leakage in the pump body 1 and the pump cover 4. At the same time, pay attention to the diversion effect of the liquid diversion pipe 14 to ensure that the liquid can be diverted normally.

[0097] Finally, the sealless pump should be maintained regularly, the wear of each component should be checked, and damaged components, including the impeller nut 201, the bearing 701, the sleeve seal 21, etc., should be replaced in time to ensure the normal operation and anti-leakage performance of the pump.

[0098] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the above specific implementation methods. Therefore, any modification or replacement of the present invention; and all technical solutions and improvements thereof that do not depart from the spirit and scope of the invention are included in the scope of the claims of the present invention.

Claims

1. A sealless pump, comprising a pump body (1), characterized in that: An impeller (2) is arranged in the pump body (1), a flow-blocking sleeve (3) is arranged above the impeller (2), a pump cover (4) is arranged above the pump body (1), and the pump cover (4) is sleeved on the outer surface of the flow-blocking sleeve (3), the front end of the pump cover (4) cooperates with the rear mouth ring of the impeller (2) to form a mouth ring gap, and the rear end of the flow-blocking sleeve (3) is a spiral groove; the spiral blades and the rear end of the pump cover (4) form a gap, and a hole is opened on the pump cover (4) in the middle of the gap, and one end of the return pipe (6) is connected to the hole at the pump cover (4), so that The other end of the return pipe (6) is connected to the low-pressure inlet of the pump body (1); a static seal (5) is provided at the connection between the baffle sleeve (3) and the pump cover (4); a return pipe (6) is provided on the pump body (1); the rear ring of the impeller (2) is extended or an extension sleeve (9) is provided inside the rear ring; the extension sleeve (9) cooperates with the rear end fixing ring of the pump cover (4) to form an end gap; a thread seal or a spiral blade seal is provided at the end gap; an opening leading to the suction side or the low-pressure side is provided between the ring gap and the end gap.

2. A sealless pump according to claim 1, characterized in that: The impeller (2) is arranged on a pump shaft (8), a bearing component (7) is arranged on the pump shaft (8), a rear cover (10) is arranged on the side of the pump body (1), and an L-shaped support seat (11) is arranged below the rear cover (10).

3. A sealless pump according to claim 2, characterized in that: An impeller nut (201) is provided at the end of the impeller (2), the bearing component (7) is provided with a bearing (701), a shaft sleeve sealing ring (21) is provided on the bearing (701), and the bearing (701) and the shaft sleeve sealing ring (21) are both sleeved on the outer surface of the pump shaft (8).

4. A sealless pump according to claim 3, characterized in that: A shunt pipe connector (13) is provided at the upper end of the extension sleeve (9), the shunt pipe connector (13) is connected to a liquid shunt pipe (14), and a V-shaped cover (12) is provided above the liquid shunt pipe (14).

5. A sealless pump according to claim 4, characterized in that: A sealing valve (15) is arranged below the pump body (1), a pressure relief valve (16) is arranged above the pump body (1), and an exhaust valve (17) is arranged at the lower middle portion of the pump body (1).

6. A sealless pump according to claim 5, characterized in that: The pump shaft (8) is provided with a shaft keyway (18), a leakproof gasket (19) is provided between the pump cover (4) and the pump body (1), and the end of the return pipe (6) is connected to a return chamber (20).

7. A method for preventing leakage of liquid diversion in a sealless pump, characterized in that: The following steps are involved: Step 1. Preparation: Ensure that all parts of the sealless pump, such as the pump body (1), impeller (2), choke sleeve (3), pump cover (4), return pipe (6), extension sleeve (9), and bearing component (7), are properly installed and in good condition; check whether the sealing valve (15), pressure relief valve (16), and exhaust valve (17) are working properly, and ensure that the shaft keyway (18) on the pump shaft (8) and the leakproof gasket (19) between the pump cover (4) and the pump body (1) are not damaged; Step 2. Start the pump: Start the sealless pump so that the impeller (2) starts to rotate driven by the pump shaft (8); Step 3. Liquid diversion: During the rotation of the impeller (2), the liquid is transported under the action of the impeller (2); the liquid diversion pipe (14) connected to the diversion pipe connector (13) at the upper end of the extension sleeve (9) diverts a portion of the liquid; the V-shaped cover (12) above the liquid diversion pipe (14) can play a certain protective role; Step 4. Pump leak prevention: Leakage prevention of mouth ring gap and end gap: the openings set between the mouth ring gap and the end gap lead to the suction side or the low-pressure side, so that the leaked liquid can flow back to the suction side or the low-pressure side through these openings; Static seal (5) at the connection between the baffle sleeve (3) and the pump cover (4): ensuring the static seal (5) at the connection between the baffle sleeve (3) and the pump cover (4); Treatment of the gap between the spiral blade and the rear end of the pump cover (4): a gap is formed between the spiral blade and the rear end of the pump cover (4), a hole is opened on the pump cover (4) in the middle of the gap, one end of the return pipe (6) is connected to the hole in the pump cover (4), and the other end is connected to the low-pressure inlet of the pump body (1); in this way, liquid leaking into the gap can flow back to the low-pressure inlet of the pump body (1) through the return pipe (6); Step 5. Pump operation monitoring: During the operation of the pump, pay close attention to the working conditions of the sealing valve (15), the pressure relief valve (16), and the exhaust valve (17), and whether there is leakage in the pump body (1) and the pump cover (4); at the same time, observe the diversion state of the liquid diversion pipe (14); Step 6. Pump maintenance: Perform regular maintenance on the sealless pump, check the wear of each component, and replace damaged components in a timely manner, including the impeller nut (201), bearing (701), and sleeve seal (21); ensure the normal operation and leakage prevention of the pump.

8. The method for preventing leakage of liquid from being split by a sealless pump according to claim 7, characterized in that: Step 4. Pump leakage prevention, the leakage formula of the end gap is: Where: Q1 is the end gap leakage; A1 is the area of ​​the end gap; ΔP1 is the end gap pressure difference; K1 is the end gap leakage coefficient.

9. The method for preventing liquid diversion and leakage of a sealless pump according to claim 7, characterized in that: Step 4. Pump leakage prevention, the leakage formula of the spiral blade gap is: Where: Q2 is the leakage of the spiral blade gap; A2 is the area of ​​the spiral blade gap; ΔP2 is the pressure difference of the spiral blade gap; K2 is the leakage coefficient of the spiral blade gap; μ(T) is the dynamic viscosity of the actual measured fluid changing with temperature, μ ref is the viscosity at standard temperature.

10. The method for preventing liquid diversion and leakage of a sealless pump according to claim 7, characterized in that: Step 4. Pump leakage prevention, the leakage amount of the mouth ring gap: Where: Q3 is the leakage of the mouth ring gap; A3 is the area of ​​the mouth ring gap; ΔP3 is the pressure difference of the mouth ring gap; K3 is the leakage coefficient of the mouth ring gap; e is the turbulence intensity coefficient; V is the velocity of the fluid; μ(T) is the dynamic viscosity of the actual measured fluid changing with temperature.

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