Pulp pump power seal structure
By utilizing fluid dynamics principles through a dynamic sealing structure, the wear and leakage problems of pulp pump sealing structures in harsh environments have been solved, achieving a leak-free, long-life, and low-maintenance sealing effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI KAIQUAN PUMP IND GROUP
- Filing Date
- 2025-08-28
- Publication Date
- 2026-08-04
AI Technical Summary
Existing pulp pump sealing structures suffer from limited sealing performance, rapid wear, frequent maintenance, and poor adaptability, and are particularly prone to failure in pulp media containing fibers and solid particles.
It adopts a non-contact dynamic sealing structure, including components such as fixed guide vanes, auxiliary impeller, sealing pump cover, valve plate, gland, and sealing shaft sleeve. It uses the principle of fluid dynamics to achieve sealing, preventing solid particles from entering the sealing cavity, and achieves leak-free operation through O-ring seals and gap design.
It achieves leak-free operation under complex working conditions, extends the service life of sealing components, reduces maintenance frequency and cost, has strong adaptability, and avoids environmental pollution.
Smart Images
Figure CN224592407U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a sealing structure, specifically a pulp pump dynamic sealing structure with good dynamic sealing performance, capable of achieving leak-free operation, effectively preventing impurities from entering the sealing device, and highly adaptable. Background Technology
[0002] Existing pulp pump technology primarily uses mechanical seals or packing seals, which have the following main drawbacks:
[0003] I. Packing Seal
[0004] 1. Limited sealing performance
[0005] Packing seals primarily rely on the tight compression of the packing material against the shaft to achieve a seal. During the operation of a pulp pump, pulp often contains solid particles such as fibers and packing material, which can easily enter the gap between the packing and the shaft. As the pump runs, these solid particles accumulate in the gap, causing wear on the sealing surfaces between the packing and the shaft, thus reducing the sealing performance.
[0006] 2. Wears out quickly and has a short service life.
[0007] There is relative movement between the packing and the shaft, and long-term friction will lead to wear on both the packing and the shaft. This wear rate is especially rapid in the transport of abrasive media such as pulp. Once the packing is severely worn, it needs to be replaced promptly; otherwise, it will lead to significant pulp leakage and affect production efficiency.
[0008] 3. Frequent maintenance
[0009] Because sealing performance deteriorates easily and wears out quickly, the packing needs to be inspected and replaced regularly. In industrial production, this increases maintenance workload and costs. Furthermore, replacing the packing requires machine shutdown, which can disrupt production schedules.
[0010] 4. Poor adaptability
[0011] Packing seals have poor adaptability to different working conditions and media. When parameters such as pulp viscosity and temperature change, it may be necessary to adjust the packing compaction or replace the packing material with a different one. Improper adjustment will affect the sealing effect.
[0012] II. Mechanical Seal
[0013] 1. Complex structure and high cost
[0014] Mechanical seals consist of several precision components, including a rotating ring, a stationary ring, a spring, and a sealing ring. Their structure is relatively complex, resulting in higher manufacturing costs. The rotating and stationary rings require high-precision machining processes to ensure a tight seal between their sealing surfaces. Due to their complex structure, installation and maintenance require specialized technicians, further increasing installation and maintenance costs.
[0015] 2. High installation accuracy required
[0016] Mechanical seals require very high installation precision. Poor alignment of the dynamic and stationary rings, or uneven sealing surfaces, during installation can lead to seal failure. Furthermore, the installation of auxiliary devices for mechanical seals, such as flushing and cooling systems, is also crucial. Incorrect pressure, flow rate, or other parameters of the flushing or cooling fluid can also affect the normal operation of the mechanical seal.
[0017] 3. Sensitive to impurity particles
[0018] Mechanical seals have a very narrow sealing surface, making it easy for solid particles from the pulp to enter between the sealing surfaces. These solid particles can scratch the sealing surface, leading to seal failure. Utility Model Content
[0019] To address the aforementioned problems, the main objective of this utility model is to provide a pulp pump dynamic sealing structure with good dynamic sealing performance, enabling leak-free operation, effectively preventing impurities from entering the sealing device, and strong adaptability.
[0020] This utility model solves the above-mentioned technical problems through the following technical solution: a dynamic sealing structure for a pulp pump, comprising: a fixed guide vane, an auxiliary impeller, a sealing pump cover, a valve plate, a pressure cap, a sealing bushing, and fastening bolts. The fixed guide vane is positioned by the pump body and the bearing housing. The sealing pump cover is positioned by the fixed guide vane and the bearing housing. The sealing pump cover is pressed tightly by the valve plate using the pressure cap and fastening bolts. The valve plate is also pressed tightly by the pressure cap and fastening bolts. When the pump stops, under the pressure of the sealing chamber, the valve plate and the sealing bushing are in contact. The sealing bushing is fixedly installed on the pump shaft.
[0021] In a specific embodiment of this utility model, the sealing bushing is installed on the pump shaft by a set screw. On the one hand, it acts as a stop end face seal by fitting with the valve plate under the pressure of the sealing cavity. On the other hand, a first O-ring is designed and installed on the inner side of the sealing bushing, which acts as an axial seal under the pressure of the sealing cavity. The sealing bushing is formed by integral casting or profile machining.
[0022] In a specific embodiment of this utility model, a sealing groove for installing an O-ring is provided on the end face where the sealing pump cover and the valve plate contact, and a second O-ring is installed in the sealing groove.
[0023] In a specific embodiment of this utility model, the secondary impeller includes a hub, a cover plate, and blades. The number of blades ranges from 10 to 12, and the secondary impeller is formed by integral casting.
[0024] In a specific embodiment of this utility model, the valve plate material is PTFE material, which is temperature resistant, corrosion resistant, and has good stability.
[0025] In a specific embodiment of this utility model, the gland is tightened onto the valve plate by fastening bolts, thereby sealing the end face of the sealing pump cover. The gland is formed by integral casting or profile processing.
[0026] In a specific embodiment of this utility model, there is a gap between the valve plate and the sealing bushing. When the pump is running normally, the valve plate and the sealing bushing do not contact each other, and the gap is 0.5mm ± 0.05mm. When the pump is stopped, the gap is 0mm.
[0027] In a specific embodiment of this utility model, there is a gap between the fixed guide vane and the auxiliary impeller, which is 0.5mm ± 0.05mm.
[0028] In a specific embodiment of this utility model, the number of fixed guide vanes ranges from 8 to 10.
[0029] The positive and progressive effects of this utility model are as follows: The pulp pump dynamic sealing structure proposed in this utility model, as a non-contact seal, has the following advantages compared with traditional sealing methods:
[0030] (1) Adaptable to complex working conditions:
[0031] Pulp pumps often operate in harsh environments, as pulp contains solid particles such as fibers and fillers. These particles can easily damage the sealing surfaces of packing seals and mechanical seals. Dynamic seals, due to their non-contact operation, are better adapted to the solid particles in pulp. The auxiliary impeller prevents the medium from entering the sealing cavity, avoiding failure of sealing components due to particle wear.
[0032] (2) Good sealing performance:
[0033] Dynamic seals ensure leak-free operation of the pump during normal operation, guaranteeing normal pump operation and media purity, eliminating leaks, spills, drips, and other contamination, preventing environmental pollution, and extending maintenance cycles.
[0034] (3) No wear on the parts:
[0035] Dynamic seals differ from contact seals such as packing seals and mechanical seals. In contact seals, there is relative movement between the sealing components, resulting in friction and wear. Dynamic seals, however, do not have direct contact and rely primarily on fluid dynamics to achieve sealing. This significantly reduces friction and wear between the sealing components, extending the seal's service life. The advantages of this non-contact seal are particularly evident during the long-term operation of pulp pumps, reducing equipment maintenance costs and repair frequency.
[0036] (4) Long service life:
[0037] Due to reduced wear, dynamic seals have longer replacement cycles. For equipment like pulp pumps that require continuous operation, longer seal life means less downtime for seal repair and replacement. Pulp pumps using dynamic seals can run continuously for months or even years without seal replacement, while pumps using packing seals or mechanical seals may require more frequent maintenance.
[0038] (5) Simple maintenance: Dynamic seals have a relatively simple structure, without as many precision components as mechanical seals, and unlike packing seals, they do not require frequent adjustments to the tightness. In daily maintenance, operators only need to perform simple inspections of the sealing area to observe for any abnormal leakage signs. Moreover, due to its non-contact operation, there is no need for complex adjustments and repairs to the sealing components.
[0039] (6) Low cost: Due to the long service life and low replacement frequency of the sealing components, the cost of the sealing components themselves is reduced. On the other hand, reducing the number of maintenance operations and maintenance time also saves labor costs and production losses caused by equipment downtime; for enterprises with large-scale production, this cost advantage is very prominent. Attached Figure Description
[0040] Figure 1 This is a schematic diagram of the overall structure of this utility model.
[0041] Figure 2 This is a front view of the auxiliary impeller in this utility model.
[0042] Figure 3 This is a cross-sectional view of the auxiliary impeller in this utility model.
[0043] The following are the names corresponding to the reference numerals in this utility model:
[0044] In the diagram above: 1. Fixed guide vane; 2. Auxiliary impeller; 3. Sealing pump cover; 4. Valve plate; 5. Pressure cover; 6. First O-ring seal; 7. Sealing bushing; 8. Set screw; 9. Fastening bolt; 10. Second O-ring seal; 2-1. Hub; 2-2. Cover plate; 2-3. Blade. Detailed Implementation
[0045] The preferred embodiments of this utility model are given below with reference to the accompanying drawings to illustrate the technical solution of this utility model in detail.
[0046] Figure 1 This is a schematic diagram of the overall structure of the present invention, as shown below. Figure 1 As shown: This utility model provides a dynamic sealing structure for a pulp pump, including a fixed guide vane 1, an auxiliary impeller 2, a sealing pump cover 3, a valve plate 4, a gland 5, a first O-ring seal 6, a sealing bushing 7, a set screw 8, a fastening bolt 9, and a second O-ring seal 10.
[0047] The fixed guide vane 1 is positioned by the pump body and bearing housing. The overall structure is designed based on the pump body, bearing housing and auxiliary impeller 2. The number of guide vane blades is generally 8-10, and the forming method is integral casting.
[0048] The secondary impeller 2 is the core component of the dynamic sealing component. The sealing pressure it generates must be greater than the liquid pressure in the sealing cavity generated by the impeller. This is necessary to prevent liquid from leaking outward, thereby reducing pump cavity pressure, balancing axial force, and preventing media particles from entering the sealing cavity.
[0049] Figure 2 This is a front view of the auxiliary impeller in this utility model. Figure 3 This is a cross-sectional view of the secondary impeller in this utility model, as shown below. Figure 2 and 3 As shown: In this utility model, the secondary impeller 2 includes a hub 2-1, a cover plate 2-2, and blades 2-3. The number of impeller blades is generally 10-12, and the forming method is integral casting.
[0050] In the secondary impeller seal, the rotation of the impeller back blade and the secondary impeller 2 is the main factor in preventing leakage of the sealing liquid. The design pressure of the entire secondary impeller 2 is the sum of the sealing pressure of the impeller back blade and the sealing pressure of the secondary impeller 2.
[0051] The sealing pump cover 3 is positioned by fixing the guide vane 1 and the bearing housing. The end face is designed to install the second O-ring seal 10. It is pressed by the valve plate 4 with the cover 5 and fastening bolts 9 to prevent the medium in the sealing cavity from leaking from the end face of the sealing pump cover when the machine is stopped, thus playing the role of end face sealing. The sealing pump cover is formed by integral casting.
[0052] The valve plate 4 is tightened by the gland 5 and the fastening bolts 9, which serves to seal the end face of the sealing pump cover 3. On the other hand, when the machine stops, under the pressure of the sealing cavity, the valve plate 4 fits against the sealing bushing 7, which serves to seal the end face when the machine stops. The valve plate 4 is made of PTFE, which is heat-resistant, corrosion-resistant and has good stability.
[0053] The pressure cap 5 presses the valve plate 4 with the fastening bolts 9, which can seal the end face of the sealing pump cover 3. The forming method is integral casting or profile processing.
[0054] The sealing bushing 7 is installed on the pump shaft by the set screw 8. On the one hand, it acts as a stop end face seal by fitting with the valve plate 4 under the pressure of the sealing cavity. On the other hand, the first O-ring seal 6 is designed and installed on the inner side of the sealing bushing, which acts as an axial seal when the pump stops under the pressure of the sealing cavity. The forming method is integral casting or profile machining.
[0055] Figure 1 S1 represents the clearance between valve plate 4 and sealing sleeve 7. When the pump is running normally, valve plate 4 and sealing sleeve 7 do not contact each other, and the clearance can be 0.5mm ± 0.05mm. When the pump is stopped, the clearance is 0mm.
[0056] Figure 1 S2 is the clearance value between the fixed guide vane 1 and the secondary impeller 2. If the clearance is too large or too small, it will affect the sealing pressure of the secondary impeller. The clearance can generally be 0.5mm ± 0.05mm.
[0057] The dynamic seal for the pulp pump proposed in this utility model is a non-contact seal. When the pump is running normally, there are gaps between the various parts of the sealing component. When the pump stops, the seal completely disengages and fails to perform its sealing function. There is zero leakage of the sealing medium and no wear on the various parts.
[0058] This invention is a typical non-contact sealing structure that utilizes fluid dynamics principles to achieve sealing. During normal pump operation, the auxiliary impeller 2 rotates, generating pressure that partially offsets the pressure generated at the impeller outlet via the fixed guide vane 1, achieving pressure balance. This ensures that the pressure at the sealing cavity is at atmospheric pressure, completely preventing the sealing slurry from entering the cavity and achieving a zero-leakage seal.
[0059] The dynamic seal of the pulp pump only plays a sealing role when the pump is running. When the pump is stopped, pressure is generated in the sealing cavity. Under the pressure of the valve plate 4 sealing cavity, it fits against the sealing sleeve 7, thus playing a sealing role when the pump is stopped.
[0060] This invention relates to a non-contact seal, which can adapt to complex working conditions: pulp pumps often operate in harsh environments, with pulp containing solid particles such as fibers and fillers. These particles can easily damage the sealing surfaces of packing seals and mechanical seals. Dynamic seals, due to their non-contact operation, are better adapted to solid particles in pulp. The auxiliary impeller prevents the medium from entering the sealing cavity, avoiding seal failure due to particle wear.
[0061] This invention features excellent sealing performance: the dynamic seal ensures zero leakage during normal pump operation, guaranteeing normal pump operation and media purity, eliminating running, leaking, dripping, and seepage, preventing environmental pollution, and extending maintenance cycles.
[0062] This invention features wear-free parts: dynamic seals differ from contact seals such as packing seals and mechanical seals. In contact seals, there is relative movement between the sealing components, resulting in friction and wear. Dynamic seals, however, do not have direct contact and rely primarily on fluid dynamics to achieve sealing. This significantly reduces friction and wear between the sealing components, extending the seal's service life. The advantages of this contactless seal are particularly evident during the long-term operation of pulp pumps, reducing equipment maintenance costs and repair frequency.
[0063] This invention offers a long service life: due to reduced wear, the dynamic seal components have a longer replacement cycle. For equipment like pulp pumps that require continuous operation, a longer seal life means less downtime for seal maintenance and replacement. Pulp pumps using dynamic seals can operate continuously for months or even years without replacing the seal components, while pumps using packing seals or mechanical seals may require more frequent maintenance.
[0064] This invention is easy to maintain: the dynamic seal structure is relatively simple, without as many precision components as a mechanical seal, and unlike a packing seal, it does not require frequent adjustments to the tightness. In routine maintenance, operators only need to perform a simple inspection of the sealing area to observe for any abnormal leaks. Furthermore, due to its non-contact operation, complex adjustments and repairs to the sealing components are unnecessary.
[0065] This invention offers low cost: the long service life and low replacement frequency of the sealing components reduce the cost of the components themselves. Furthermore, reduced maintenance frequency and time also save on labor costs and production losses caused by equipment downtime. This cost advantage is particularly significant for large-scale production enterprises.
[0066] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection of this utility model as defined by the appended claims and their equivalents.
Claims
1. A pulp pump power seal structure, characterized by: The pulp pump dynamic sealing structure includes: a fixed guide vane, an auxiliary impeller, a sealing pump cover, a valve plate, a gland, a sealing shaft sleeve, and fastening bolts. The fixed guide vane is positioned by the pump body and the bearing housing. The sealing pump cover is positioned by the fixed guide vane and the bearing housing. The sealing pump cover is pressed tightly by the valve plate with the gland and fastening bolts. The valve plate is pressed tightly by the gland and fastening bolts. When the pump stops, under the pressure of the sealing chamber, the valve plate and the sealing shaft sleeve are in contact. The sealing shaft sleeve is fixedly installed on the pump shaft.
2. The paper pulp pump power seal structure of claim 1, wherein: The sealing bushing is installed on the pump shaft by set screws. On the one hand, it acts as a sealing surface at the shutdown end by fitting with the valve plate under the pressure of the sealing cavity. On the other hand, a first O-ring is designed and installed on the inner side of the sealing bushing, which acts as an axial sealing surface at shutdown under the pressure of the sealing cavity. The sealing bushing is formed by integral casting or profile machining.
3. The paper pulp pump power seal structure of claim 1, wherein: The end face where the sealing pump cover and the valve plate contact is provided with a sealing groove for installing an O-ring, and a second O-ring is installed in the sealing groove.
4. The paper pulp pump power seal structure of claim 1, wherein: The secondary impeller includes a hub, a cover plate, and blades. The number of blades ranges from 10 to 12. The secondary impeller is formed by integral casting.
5. The dynamic sealing structure for a pulp pump according to claim 1, characterized in that: The valve plate is made of PTFE, which is temperature resistant, corrosion resistant, and has good stability.
6. The dynamic sealing structure for a pulp pump according to claim 1, characterized in that: The gland is tightened onto the valve plate by fastening bolts, which serves to seal the end face of the sealing pump cover. The gland is formed by integral casting or profile machining.
7. The dynamic sealing structure for a pulp pump according to claim 1, characterized in that: There is a gap between the valve plate and the sealing bushing. When the pump is running normally, the valve plate and the sealing bushing do not contact each other, and the gap is 0.5mm ± 0.05mm. When the pump is stopped, the gap is 0mm.
8. The dynamic sealing structure for a pulp pump according to claim 1, characterized in that: There is a gap between the fixed guide vane and the auxiliary impeller, which is 0.5mm ± 0.05mm.
9. The dynamic sealing structure for a pulp pump according to claim 1, characterized in that: The number of blades in a fixed guide vane ranges from 8 to 10.