Medium-concentration paper pulp pump

Abstract

The medium-concentration paper pulp pump comprises a pump body, a pump cover connected with the pump body in a matched mode, a main shaft penetrating through the pump cover and a shaft sleeve arranged on the main shaft in a sleeving mode, a gland is fixedly connected to the outer end face of the pump cover, the main shaft and the shaft sleeve penetrate through the gland, and a backflow cavity is defined by part of the inner end face of the gland, part of the outer end face of the pump cover and part of the outer circle face of the shaft sleeve. According to the designed medium-concentration paper pulp pump, an efficient lubricating and cooling system is constructed, that is, lubricating oil forms circulation in the backflow cavity, the tooth-shaped sealing structure can be effectively lubricated, friction is reduced, the service life is prolonged, heat generated in a sealing area can be continuously taken away, and sealing failure caused by overheating is prevented; the pressure in the backflow cavity is higher than the pressure in the pump body, a pressure difference is formed, the possibility that paper pulp enters a sealing face when the pump operates at a high height is effectively prevented, the sealing performance is further improved, and long-term stable operation of the pump is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of pump sealing, in particular to a medium-consistency pulp pump. Background Art

[0002] In the existing technology, medium-consistency pulp pumps are key equipment for conveying pulp containing solid particles in the papermaking industry, and their sealing performance directly affects the efficiency, reliability and service life of the pump. In order to prevent pulp leakage and improve the efficiency and reliability of the pump, medium-consistency pulp pumps usually require special sealing technology.

[0003] Traditional pulp pump seals mainly use mechanical seals, including single-end mechanical seals, double-end mechanical seals, etc. However, since pulp contains a large amount of solid particles, these particles can easily enter the friction pair of the mechanical seal, causing wear and leakage of the sealing surface, which undoubtedly increases the maintenance workload and cost.

[0004] In order to solve the problems of traditional mechanical seals, some new sealing technologies have emerged in recent years, such as using compressed packing to achieve sealing, but its friction is large, it is easy to heat up, and the sealing effect is unstable. Therefore, the existing axial sealing technology of medium-consistency pulp pumps has certain limitations and it is difficult to fully meet the requirements for sealing performance, especially under harsh working conditions such as high concentration, high head, and strong corrosiveness, traditional mechanical seals are more likely to have problems. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a medium-consistency pulp pump which solves the problems of wear and leakage, low efficiency and complicated maintenance of traditional mechanical seals.

[0006] In order to achieve the above-mentioned purpose, the medium-consistency pulp pump designed by the present invention comprises a pump body, a pump cover matched with the pump body, a main shaft passing through the pump cover and a sleeve sleeved on the main shaft, the outer end face of the pump cover is fixedly connected with a pressure cover, the main shaft and the sleeve pass through the pressure cover, and a reflux chamber is defined between a part of the inner end face of the pressure cover, a part of the outer end face of the pump cover and a part of the outer circumferential surface of the sleeve; an oil inlet and an oil return port connected to the reflux chamber are provided on the pump cover, and the oil inlet and the oil return port are used to connect to an external lubricating oil system; a sealing block is arranged in the reflux chamber, the sealing block is fixedly connected to the outer circumferential surface of the sleeve, and a plurality of sealing teeth extending along the rotation direction of the main shaft and connected end to end are provided on the surface of the sealing block facing the pump cover, and the plurality of sealing teeth are distributed along the radial direction of the main shaft; a toothed structure is provided on the outer end face of the pump cover, which is fitted with the gap between the sealing teeth; wherein the pressure in the reflux chamber is higher than the pressure in the pump body.

[0007] Furthermore, the radial cross-section of the sealing tooth is in the shape of a right triangle.

[0008] Furthermore, a gap between the sealing teeth and the toothed structure on the pump cover is 1 mm to 2 mm.

[0009] Furthermore, the sealing block is an annular structure that is interference fit with the shaft sleeve.

[0010] Furthermore, the shaft sleeve is provided with a limiting boss extending radially along the shaft sleeve, and the sealing block has an abutting surface opposite to the limiting boss; a locking sleeve is provided on the outer circumferential surface of the shaft sleeve, and the locking sleeve abuts against the side of the sealing block away from the limiting boss.

[0011] Furthermore, the locking sleeve is provided with a plurality of adjusting bolts spaced apart along the circumference of the sleeve; each of the adjusting bolts abuts against a side of the sealing block away from the limiting boss to adjust the gap between the sealing block and the toothed structure on the pump cover.

[0012] Furthermore, the sealing block is made of silicon carbide.

[0013] Furthermore, the oil inlet is located below the main shaft, and the oil return port is located above the main shaft.

[0014] Furthermore, an extension portion extending toward the sealing block is provided on the inner end surface of the gland, and a lip seal ring is provided on the surface of the extension portion facing the sealing block and on the surface of the gland facing the shaft sleeve.

[0015] Furthermore, the extension portion separates the reflux chamber to form a first chamber and a second chamber, the oil inlet and the oil return port are connected to the first chamber, the locking sleeve and the adjusting bolt are located in the second chamber, and the extension portion is provided with a through hole connecting the first chamber and the second chamber.

[0016] The medium-consistency pulp pump designed by the present invention integrates the design of the radial non-contact sealing structure, the outer pressure cover and the lip sealing ring as well as the reflux chamber, effectively solving the problems of friction, wear, leakage and high maintenance cost existing in traditional mechanical seals, and effectively eliminating the friction pair of traditional mechanical seals, and preventing the occurrence of wear and leakage, especially under harsh working conditions such as high concentration, high head and strong corrosiveness, the advantages are more obvious; at the same time, the setting of the outer pressure cover and the lip sealing ring further enhances the reliability of the seal and prevents the leakage of pulp when the pump is stationary or running at a low speed. It is worth mentioning that the present invention connects the oil inlet and oil return port connected to the reflux chamber with the external lubricating oil system, thereby constructing an efficient lubrication and cooling system, that is, the lubricating oil circulates in the reflux chamber, which can not only effectively lubricate the toothed sealing structure, reduce friction, and extend the service life, but also continuously take away the heat generated in the sealing area to prevent seal failure caused by overheating. In addition, the pressure in the reflux chamber is higher than the pressure in the pump body, thereby forming a pressure difference, which effectively prevents the possibility of pulp entering the sealing surface when the pump is running at high speed, thereby further improving the sealing performance and ensuring the long-term stable operation of the pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the planar structure of a medium-consistency pulp pump provided in an embodiment of the present application.

[0018] Figure 2 yes Figure 1 Enlarged schematic diagram at point A in the middle.

[0019] Figure 3 yes Figure 1 Enlarged schematic diagram of point B in the middle.

[0020] Figure 4 yes Figure 3 Enlarged schematic diagram at point C in the middle.

[0021] Figure 5 It is a schematic diagram of the three-dimensional structure of the sealing block in the embodiment of the present application.

[0022] Among them: pump body 10, pump cover 20, toothed structure 21, main shaft 30, sleeve 40, limiting boss 41, locking sleeve 42, joint bolt 43, pressure cover 50, extension part 51, through hole 52, reflux chamber 60, first chamber 60a, second chamber 60b, oil inlet 61, oil return port 62, sealing block 70, sealing teeth 71, abutment surface 72, lip sealing ring 80. DETAILED DESCRIPTION

[0023] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0024] like Figures 1 to 5As shown, the medium-consistency pulp pump described in this embodiment is applied to medium-consistency pulp transportation in paper mills. The medium-consistency pulp pump specifically comprises a pump body 10, a pump cover 20 matched with the pump body 10, a main shaft 30 passing through the pump cover 20, and a sleeve 40 sleeved on the main shaft 30. The outer end surface of the pump cover 20 is fixedly connected with a gland 50. The main shaft 30 and the sleeve 40 pass through the gland 50. A reflux chamber 60 is defined between a part of the inner end surface of the gland 50, a part of the outer end surface of the pump cover 20, and a part of the outer circumferential surface of the sleeve 40. The pump cover 20 is provided with an oil inlet 61 and an oil return port 62 connected to the reflux chamber 60. The oil inlet 61 and the oil return port 62 are connected to the reflux chamber 60. The oil return port 62 is used to connect to an external lubricating oil system; a sealing block 70 is arranged in the reflux chamber 60, and the sealing block 70 is fixedly connected to the outer circumferential surface of the shaft sleeve 40, and a plurality of sealing teeth 71 extending along the rotation direction of the main shaft 30 and connected end to end are arranged on the surface of the sealing block 70 facing the pump cover 20, and the plurality of sealing teeth 71 are distributed along the radial direction of the main shaft 30; a toothed structure 21 is provided on the outer end surface of the pump cover 20, which is gap-fitted with the sealing teeth 71; wherein, the pressure in the reflux chamber 60 is higher than the pressure in the pump body 10.

[0025] In specific implementation, the medium-consistency pulp pump is installed on the pulp conveying pipeline of the paper mill to convey the pulp containing solid particles. When the external drive motor (not shown) drives the main shaft 30 to rotate, the sleeve 40 connected to the main shaft 30 and the sealing block 70 fixed on the sleeve 40 also rotate at high speed. In this embodiment, Figure 5 As shown, the sealing block 70 is an annular structure that is interference fit with the shaft sleeve 40 .

[0026] At this time, if Figure 2 and Figure 3 As shown, the toothed structure 21 on the outer end surface of the pump cover 20 forms a clearance fit with the sealing teeth 71 on the sealing block 70, and a radial contactless seal is formed when the main shaft 30 rotates at high speed. In this process, the external lubricating oil system continuously provides clean lubricating oil and maintains a certain pressure, that is, the lubricating oil enters the reflux chamber 60 through the oil inlet 61 on the pump cover 20. The lubricating oil entering the reflux chamber 60 can not only play a lubricating role, but also take away the heat from the sealing area, effectively reducing the temperature and preventing the sealing structure from wearing and overheating. After completing the lubrication and cooling tasks, the lubricating oil flows back to the lubricating oil system through the oil return port 62 for filtration and cooling to achieve recycling.

[0027] In the above process, due to the pressure control of the lubricating oil system, the pressure in the reflux chamber 60 is always higher than the pressure in the pump body 10, forming a pressure difference, which actively prevents the pulp from entering the reflux chamber 60, i.e., the sealing surface, from the gap between the sealing tooth 71 and the tooth structure 21, thereby ensuring the reliability of the seal.

[0028] In this way, since the radial non-contact seal structure eliminates the friction pair of the traditional mechanical seal, the wear and leakage problems are fundamentally eliminated, and the service life and reliability of the medium-consistency pulp pump are significantly improved. Especially under harsh working conditions such as high concentration, high head, and strong corrosiveness, the advantages of non-contact seals are more prominent. It can not only ensure the long-term stable operation of the pump, but also effectively reduce the operating energy consumption of the pump and improve the efficiency of the pump.

[0029] In some embodiments, Figure 4 As shown, the radial cross-section of the sealing tooth 71 is a right triangle. In this embodiment, the triangular tooth shape has a small leakage, which can effectively prevent pulp from leaking through the tooth gap and improve the sealing performance.

[0030] In some embodiments, Figure 4 As shown, the gap between the sealing teeth 71 and the toothed structure 21 on the pump cover 20 is 1 mm to 2 mm. In this embodiment, the gap of 1 mm to 2 mm is sufficient to ensure that the sealing teeth 71 and the toothed structure 21 do not contact and rub against each other during high-speed rotation, and at the same time, a certain manufacturing error and thermal expansion of sealing components such as the sealing block 70 and the sealing teeth 71 at the working temperature can be allowed to ensure the normal operation of the sealing structure.

[0031] In some embodiments, Figure 2 As shown, the shaft sleeve 40 is provided with a limiting boss 41 extending radially along the shaft sleeve 40, and the sealing block 70 has an abutting surface 72 opposite to the limiting boss 41; a locking sleeve 42 is provided on the outer circumferential surface of the shaft sleeve 40, and the locking sleeve 42 abuts against the side of the sealing block 70 away from the limiting boss 41. In this way, the cooperation between the limiting boss 41 and the abutting surface 72 can limit the minimum distance of the sealing block 70 close to the toothed structure 21 along the axial direction of the shaft sleeve 40, avoid the generation of friction and prevent the sealing from failing, and the locking sleeve 42 can serve as a physical defense line to firmly fix the sealing block 70 on the shaft sleeve 40, prevent the sealing block 70 from loosening or falling off during high-speed rotation, and improve the reliability of the seal.

[0032] In some embodiments, Figure 3 As shown, the locking sleeve 42 is provided with a plurality of adjusting bolts 43 spaced apart along the circumference of the shaft sleeve 40; each of the adjusting bolts 43 abuts against the side of the sealing block 70 away from the limiting boss 41 to adjust the gap between the sealing block 70 and the toothed structure 21 on the pump cover 20. In specific implementation, the position of the locking sleeve 42 can be precisely adjusted by rotating the adjusting bolts 43, thereby fine-tuning the gap between the sealing block 70 and the toothed structure 21, so that the sealing structure can adapt to different working conditions, such as high-concentration pulp, high head, etc., to achieve the best sealing effect.

[0033] In some embodiments, the sealing block 70 is made of silicon carbide. Compared with other materials, silicon carbide has excellent wear resistance, corrosion resistance, and high temperature resistance, and its thermal conductivity is better than most non-metallic materials, which can quickly dissipate the heat generated in the sealing area, reduce the temperature of the sealing area, and further improve the sealing performance and service life.

[0034] In some embodiments, Figure 1 As shown, the oil inlet 61 is located below the main shaft 30, and the oil return port 62 is located above the main shaft 30. With this structural design, during the circulation of the lubricating oil, since the hot oil has a low density and is easy to flow upward, the oil return port 62 is arranged at the top, which is conducive to the discharge of the hot oil, promotes the circulation of the lubricating oil, and improves the cooling effect. At the same time, the air in the reflux chamber 60 is easy to accumulate at the top. The oil return port 62 is arranged at the top, which can conveniently discharge the air in the reflux chamber 60 and avoid air blockage affecting the flow and sealing effect of the lubricating oil.

[0035] In some embodiments, Figure 2 and Figure 3 As shown, an extension portion 51 extending toward the sealing block 70 is provided on the inner end surface of the gland 50, and a lip seal ring 80 is provided on the surface of the extension portion 51 facing the sealing block 70 and the surface of the gland 50 facing the shaft sleeve 40. The lip seal ring 80 is installed between the extension portion 51 and the gland 50, forming two effective isolation barriers, which can effectively prevent pulp from leaking from the gap between the main shaft 30 and the shaft sleeve 40 when the pump is stationary or running at a low speed, effectively prevent pulp from entering the reflux chamber 60 to contaminate the lubricating oil, and also prevent the lubricating oil from leaking out of the pump body 10, further improving the sealing performance of the pump.

[0036] In some embodiments, Figure 1 , Figure 2 and Figure 3 As shown, the extension portion 51 separates the reflux chamber 60 to form a first chamber 60a and a second chamber 60b, the oil inlet 61 and the oil return port 62 are connected to the first chamber 60a, the locking sleeve 42 and the adjusting bolt 43 are located in the second chamber 60b, and the extension portion 51 is provided with a through hole 52 connecting the first chamber 60a and the second chamber 60b.

[0037] With this structural design, after the lubricating oil enters the first chamber 60a from the oil inlet 61, it can enter the second chamber 60b through the through hole 52, lubricate the locking sleeve 42 and the adjusting bolt 43, and allow the lubricating oil to fully contact the sealing block 70 without reducing too much heat dissipation area due to the provision of the extension portion 51, thereby being able to quickly dissipate the heat generated in the sealing area, effectively reducing the temperature of the sealing area, and improving the sealing performance and stability.

[0038] The medium-consistency pulp pump provided in this embodiment integrates the design of radial non-contact sealing structure, outer gland and lip seal ring and reflux chamber, effectively solves the problems of friction, wear, leakage and high maintenance cost existing in traditional mechanical seals, effectively eliminates the friction pair of traditional mechanical seals, and prevents the occurrence of wear and leakage, especially under harsh working conditions such as high concentration, high head and strong corrosiveness, the advantages are more obvious; at the same time, the setting of the outer gland and lip seal ring further enhances the reliability of the seal, and prevents the leakage of pulp when the pump is stationary or running at low speed. It is worth mentioning that the present invention connects the oil inlet and oil return port connected to the reflux chamber with the external lubricating oil system to construct an efficient lubrication and cooling system, that is, the lubricating oil forms a cycle in the reflux chamber, which can not only effectively lubricate the toothed sealing structure, reduce friction and extend the service life, but also continuously take away the heat generated in the sealing area to prevent the sealing failure caused by overheating. In addition, the pressure in the reflux chamber is higher than the pressure in the pump body, forming a pressure difference, which effectively prevents the possibility of pulp entering the sealing surface when the pump is running at high speed, further improves the sealing performance and ensures the long-term stable operation of the pump.

[0039] In the description of the present invention, it should be noted that the terms "vertical", "up", "down", "horizontal", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0040] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A medium-consistency pulp pump, comprising a pump body, a pump cover connected to the pump body, a main shaft passing through the pump cover, and a shaft sleeve sleeved on the main shaft, characterized in that: The outer end surface of the pump cover is fixedly connected with a pressure cover, the main shaft and the sleeve pass through the pressure cover, and a reflux chamber is defined between part of the inner end surface of the pressure cover, part of the outer end surface of the pump cover and part of the outer cylindrical surface of the sleeve; the pump cover is provided with an oil inlet and an oil return port connected to the reflux chamber, and the oil inlet and oil return port are used to connect to an external lubricating oil system; a sealing block is arranged in the reflux chamber, the sealing block is fixedly connected to the outer cylindrical surface of the sleeve, and a plurality of sealing teeth extending along the rotation direction of the main shaft and connected end to end are provided on the surface of the sealing block facing the pump cover, and the plurality of sealing teeth are distributed along the radial direction of the main shaft; a toothed structure is provided on the outer end surface of the pump cover, which is fitted with the gap between the sealing teeth; wherein the pressure in the reflux chamber is higher than the pressure in the pump body.

2. The medium-consistency pulp pump according to claim 1, characterized in that: The radial cross-section of the sealing tooth is a right triangle.

3. The medium-consistency pulp pump according to claim 2, characterized in that: The gap between the sealing teeth and the toothed structure on the pump cover is 1 mm to 2 mm.

4. The medium-consistency pulp pump according to claim 1, characterized in that: The sealing block is an annular structure which is interference-fitted with the shaft sleeve.

5. The medium-consistency pulp pump according to claim 1, characterized in that: The shaft sleeve is provided with a limiting boss extending radially along the shaft sleeve, and the sealing block has an abutting surface opposite to the limiting boss; a locking sleeve is provided on the outer circumferential surface of the shaft sleeve, and the locking sleeve abuts against the side of the sealing block away from the limiting boss.

6. The medium-consistency pulp pump according to claim 5, characterized in that: The locking sleeve is provided with a plurality of adjusting bolts spaced apart along the circumference of the shaft sleeve; each of the adjusting bolts abuts against a side of the sealing block away from the limiting boss to adjust the gap between the sealing block and the toothed structure on the pump cover.

7. The medium-consistency pulp pump according to any one of claims 1 to 6, characterized in that: The sealing block is made of silicon carbide.

8. The medium-consistency pulp pump according to any one of claims 1 to 6, characterized in that: The oil inlet is located below the main shaft, and the oil return port is located above the main shaft.

9. The medium-consistency pulp pump according to claim 6, characterized in that: An extension portion extending toward the sealing block is disposed on the inner end surface of the gland, and a lip seal ring is disposed on the surface of the extension portion facing the sealing block and on the surface of the gland facing the shaft sleeve.

10. The medium-consistency pulp pump according to claim 9, characterized in that: The extension portion separates the return chamber to form a first chamber and a second chamber, the oil inlet and the oil return port are connected to the first chamber, the locking sleeve and the adjusting bolt are located in the second chamber, and the extension portion is provided with a through hole connecting the first chamber and the second chamber.

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