A cutting structure of a front cover plate of a miscellaneous impeller

Abstract

The utility model relates to a kind of cutting structure of miscellaneous dirt pump impeller front cover plate, including the inside surface of front cover plate is provided with variable pitch cutting thread, from import end to outlet end pitch linearly decreases, forms gradient pitch field, transition section between import end and outlet end;The helix angle of cutting thread gradually decreases from import end to outlet end.The large pitch and large helix angle structure of import end can quickly guide fiber material into cutting zone, effectively prevent entrance blockage;The small pitch and small helix angle structure of outlet end, so that chopping force is continuously, evenly distributed along axial direction, while increasing the shear frequency between rotating blade and fixed thread.The gradual change design of pitch and helix angle makes shear frequency from low to high, realizes the progressive comminution to material, avoids that fiber is wound in single position, significantly improves the chopping efficiency of long fiber material, ensures the reliable operation of pump.

Description

Technical Field

[0001] This utility model relates to a front cover plate cutting structure, specifically a front cover plate cutting structure for a sludge pump that overcomes the shortcomings of low efficiency and easy entanglement when the screw thread of the front cover plate of the impeller of the sludge pump is cut to process long fiber materials, effectively prevents inlet blockage, and ensures reliable operation of the pump. Background Technology

[0002] Sludge pumps are widely used in municipal sewage treatment and industrial wastewater discharge, primarily for conveying fluids containing solid particles, long fibers, and other impurities. A structure that uses a threaded front cover plate in conjunction with a semi-open impeller to shred fibrous materials entering the impeller is considered ideal in terms of cost and complexity. The cutting structure of the front cover plate plays a crucial role in the pump's operating efficiency and reliability. In existing technologies, the cutting threads on the front cover plate of sludge pump impellers often employ a constant pitch and a single helix angle design. However, this constant pitch structure has significant shortcomings when handling long fibrous materials, failing to balance rapid material introduction with efficient shredding, which can severely impact the pump's normal operation. Furthermore, the single helix angle design concentrates shear force in a localized area, causing uneven thread wear and reducing service life.

[0003] Figure 1 This is a schematic diagram of the overall structure of the existing cutting structure. Figure 2 for Figure 1 The enlarged view shows that the semi-open impeller and the front cover plate are two separate parts. The front cover plate is threaded and mates with the semi-open impeller. When the impeller rotates, the blade rims and threads have a relative cutting action, which can shred fibrous materials entering the impeller. However, the thread pitch P of the front cover plate is fixed (see [reference]). Figure 2 When long fibers enter the cutting zone (with a fixed pitch), the shearing frequency remains constant, making them prone to entanglement in a single location. This can lead to inlet blockage or residual long fibers at the outlet, severely impacting the pump's normal operation. Furthermore, this single helix angle concentrates shearing force in a localized area, causing uneven thread wear and reducing service life. Utility Model Content

[0004] To address the aforementioned problems, the main objective of this utility model is to provide a cutting structure for the impeller front cover plate of a sludge pump that overcomes the shortcomings of low efficiency and easy entanglement when processing long fibrous materials using the threaded cutting of the impeller front cover plate of a sludge pump in the prior art, effectively preventing inlet blockage and ensuring reliable pump operation.

[0005] This utility model solves the above-mentioned technical problems through the following technical solution: a cutting structure for the front cover plate of a sludge pump impeller, wherein the cutting structure includes a variable pitch cutting thread provided on the inner side of the front cover plate, the pitch of which decreases linearly from the inlet end to the outlet end, forming a gradient pitch field, and the inlet end and the outlet end are a transition section; the helix angle of the cutting thread gradually decreases from the inlet end to the outlet end.

[0006] In a specific embodiment of this utility model: the pitch at the inlet end is 8-10mm, the pitch at the outlet end is 3-5mm, and the pitch at the transition section is 6-7mm.

[0007] In a specific embodiment of this utility model: the inlet end is a large pitch section, which accounts for 25-35% of the total thread length; the outlet end is a small pitch section, which accounts for 45-55% of the total thread length.

[0008] In a specific embodiment of this utility model: the large pitch section at the inlet end accounts for 30% of the total thread length; the small pitch section at the outlet end accounts for 50% of the total thread length.

[0009] In a specific embodiment of this utility model: the helix angle of the cutting thread gradually changes from 20° to 30° at the inlet end to 5° to 15° at the outlet end.

[0010] The positive and progressive effects of this utility model are as follows: The cutting structure of the impeller front cover plate of the sewage pump provided by this utility model has the following advantages: This utility model overcomes the defects of low efficiency and easy entanglement when the equal pitch cutting thread of the impeller front cover plate of the sewage pump is used to process long fiber materials.

[0011] The large pitch and large helix angle structure at the inlet end of this invention can quickly guide fibrous materials into the cutting zone, effectively preventing inlet blockage; the small pitch and small helix angle structure at the outlet end ensures that the chopping force is continuously and evenly distributed along the axial direction, while increasing the shearing frequency between the rotating blades and the fixed thread. The gradual design of the pitch and helix angle allows the shearing frequency to increase from low to high, achieving progressive crushing of the material, avoiding fiber entanglement in a single position, significantly improving the chopping efficiency of long fiber materials, and ensuring reliable pump operation. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the existing cutting structure.

[0013] Figure 2 for Figure 1 A magnified view of a portion of the image.

[0014] Figure 3 This is a schematic diagram of the overall structure of this utility model.

[0015] Figure 4 for Figure 3A magnified view of a portion of the image.

[0016] The following are the names corresponding to the reference numerals in this utility model:

[0017] In the diagram: Variable pitch cutting thread 100, inlet end 101, outlet end 103, transition section 102 Detailed Implementation

[0018] 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.

[0019] Figure 3 This is a schematic diagram of the overall structure of this utility model. Figure 4 for Figure 3 A magnified view of a portion, such as Figure 3 and 4 As shown: This utility model proposes a cutting structure for the impeller front cover plate of a sludge pump. This cutting structure includes a variable pitch cutting thread 100 on the inner side of the front cover plate. The pitch decreases linearly from the inlet end 101 to the outlet end 103, forming a gradient pitch field. The inlet pitch is 8-10mm, the outlet pitch is 3-5mm, and the transition section 102 has a pitch of 6-7mm. The large pitch section at the inlet accounts for 25-35% of the total thread length, typically 30%, which can quickly grasp long fibers and guide them to the cutting area. The small pitch section at the outlet accounts for 45-55% of the total thread length, typically 50%, which increases the number of cutting blades per unit length and improves the chopping frequency. Simultaneously, the helix angle of the cutting thread gradually changes from 20°–30° at the inlet end to 5°–15° at the outlet end. The large helix angle at the inlet reduces cutting resistance, while the small helix angle at the outlet enhances the shearing effect. The gradual helix angle ensures that the shear force is evenly distributed along the axial direction, while taking into account the requirements of material guidance and shear frequency, thus improving the processing effect on long fiber materials.

[0020] The working process of this utility model is as follows: When the impeller rotates, the fibrous material in the sewage is sucked in and comes into contact with the large pitch and large helix angle section of the front cover plate inlet, which quickly guides the fibrous material into the cutting zone. Under the guidance of the variable pitch thread, the fibrous material moves towards the outlet, passing through the small pitch and small helix angle section, and is shredded by the relative movement of the front cover plate thread and the impeller blade rim. The large pitch and large helix angle structure at the inlet end can quickly guide the fibrous material into the cutting zone, effectively preventing inlet blockage; the small pitch and small helix angle structure at the outlet end can increase the shearing frequency between the rotating blade and the fixed thread, while simultaneously creating a squeezing and pressurizing effect on the material, making the fibers taut. The gradual design of the helix angle from large to small makes the shredding force continuously and evenly distributed along the axial direction, and the shearing frequency from low to high, realizing the gradual crushing of the material, avoiding the fiber from entangled in a single position, significantly improving the shredding efficiency of long fiber materials, and ensuring the reliable operation of the pump.

[0021] Below is a specific implementation example: Taking a DN150 sewage pump as an example: the cut thread length L = 120mm, the inlet pitch is 9mm, and the outlet pitch is 4mm; the inlet helix angle is 22°, and the outlet helix angle is 10°. Compared with the traditional fixed pitch and helix angle cutting structure, the estimated clogging frequency is reduced by 75%, and energy consumption is reduced by 10%.

[0022] 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 cutting structure for the front cover plate of a sludge pump impeller, characterized in that: The impeller front cover plate cutting structure of the sewage pump includes a variable pitch cutting thread on the inner side of the front cover plate. The pitch decreases linearly from the inlet end to the outlet end, forming a gradient pitch field. There is a transition section between the inlet end and the outlet end. The helix angle of the cutting thread gradually decreases from the inlet end to the outlet end.

2. The cutting structure of the impeller front cover plate of the sewage pump according to claim 1, characterized in that: The pitch at the inlet end is 8-10mm, the pitch at the outlet end is 3-5mm, and the pitch at the transition section is 6-7mm.

3. The cutting structure of the impeller front cover plate of the sewage pump according to claim 1, characterized in that: The inlet end is a large pitch section, which accounts for 25-35% of the total thread length; the outlet end is a small pitch section, which accounts for 45-55% of the total thread length.

4. The cutting structure of the impeller front cover plate of the sewage pump according to claim 3, characterized in that: The large-pitch section at the inlet end accounts for 30% of the total thread length; the small-pitch section at the outlet end accounts for 50% of the total thread length.

5. The cutting structure of the impeller front cover plate of the sewage pump according to claim 1, characterized in that: The helix angle of the cutting thread gradually changes from 20° to 30° at the inlet end to 5° to 15° at the outlet end.

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