A screw conveyor for breaking up a filter cake in a plate and frame filter

Abstract

The utility model discloses a kind of spiral conveying devices capable of breaking plate-and-frame filter cake, belong to spiral conveyor technical field.Device includes shell, main shaft being rotatably arranged in shell and spiral blade being fixed to main shaft, spiral blade is provided with opening along radial direction, opening is provided with grid fixed to shell, and grid divides conveying channel into segments.30%-40% moisture content plate-and-frame filter cake is extruded through grid to realize breaking in conveying.The grid spacing gradually decreases from the feed inlet to the discharge outlet, the opening is adapted to the grid, and the spiral blade does not contact the grid when rotating.The device integrates conveying and breaking, is simple in structure, suitable for fly ash resource and chemical field, reduces independent breaking equipment, reduces investment and energy consumption, and improves process efficiency.

Description

Technical Field

[0001] This utility model belongs to the technical field of screw conveyors and relates to a screw conveying device for crushable plate and frame filter cakes. Background Technology

[0002] Screw conveyors, as a common type of solid material conveying equipment, are widely used in industries such as fly ash resource utilization, chemical industry, building materials, and metallurgy due to their advantages of simple structure, low failure rate, small footprint, and low manufacturing cost. Their main structure includes a shell, main shaft, helical blades, and drive unit. The rotation of the helical blades pushes the material axially to the discharge port. Screw conveyors typically convey granular, powdery, or lumpy solids and are suitable for various working conditions. However, in practical applications, many materials require further processing after conveying, such as flash drying, washing, and chemical reactions. Pre-treatment of the material during conveying (such as crushing) can significantly improve the efficiency of subsequent processes, reduce energy consumption, and optimize the process flow.

[0003] In fly ash resource utilization and chemical production, plate and frame filter presses are commonly used solid-liquid separation equipment, with the output filter cake typically having a moisture content between 30% and 40%. This type of filter cake possesses a certain structural strength and viscosity, and is in the form of cakes or blocks, making it difficult to directly proceed with subsequent processing. Traditional methods usually involve adding independent crushing equipment after conveying, such as jaw crushers or hammer crushers, to break the filter cake to a particle size suitable for subsequent processes. However, separate crushing equipment not only increases equipment investment and maintenance costs but also raises energy consumption and floor space requirements. Furthermore, ordinary crushing equipment is ineffective when processing filter cakes with a moisture content of 30%-40%, as the stickiness of the filter cake can lead to equipment blockage or low crushing efficiency, failing to meet the demands of high-efficiency and energy-saving production.

[0004] To address the aforementioned problems, existing technologies have proposed several screw conveyors with crushing functions. For example, Chinese patent document CN105883311A discloses a screw conveyor with a crushing function, which uses a support arm on the main shaft and movable hammers mounted on the support arm to crush materials by the rotation of the screw. This solution is effective in processing dry or low-moisture materials, but its crushing effect is significantly reduced for plate and frame filter cakes with a moisture content of 30%-40%. This is because the stickiness and toughness of the filter cake make it difficult for hammer crushing to effectively disperse the material, and the hammers are easily adhered to by sticky materials, leading to reduced crushing efficiency. In addition, the support arm and hammer structure of this solution are relatively complex, resulting in high manufacturing and maintenance costs, and the high-speed rotation of the hammers may cause vibration and noise, which is detrimental to the long-term stable operation of the equipment. Therefore, this technical solution has obvious limitations in processing high-moisture filter cakes and is difficult to promote and apply.

[0005] Other technical solutions attempt to achieve material crushing by modifying the shape of the spiral blades or adding shearing structures, but these solutions are usually designed for low-viscosity or loose materials and have limited crushing effect on plate and frame filter cakes. Furthermore, existing technologies lack dedicated crushing and conveying equipment for filter cakes with a moisture content of 30%-40%, requiring additional crushing steps in the production process, increasing process complexity and energy consumption. Therefore, there is an urgent need for a spiral conveying device that is simple in structure, low in cost, and suitable for plate and frame filter cakes with high moisture content, capable of effective crushing during conveying, reducing subsequent processing steps, and improving overall process efficiency. Utility Model Content

[0006] In view of this, the purpose of this utility model is to solve the above problems and provide a screw conveyor for crushable plate and frame filter cake.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A screw conveyor for crushable plate and frame filter cake includes a housing and a main shaft rotatably disposed within the housing, and screw blades fixedly disposed on the main shaft. The screw blades have openings along their radial direction, and a grid fixed within the housing is disposed within the openings. The grid divides the conveying channel formed by the screw blades into segments. The conveyed cake material is squeezed through the grid during the conveying process, thereby achieving crushing.

[0009] Furthermore, the openings are distributed in multiple ways along the main axis.

[0010] Furthermore, the housing is provided with a feed inlet and a discharge outlet, and along the axial direction of the main shaft, the gap between the grid bars of the grid near the feed inlet is greater than the gap between the grid bars of the grid near the discharge outlet.

[0011] Furthermore, from the inlet to the outlet, the gap between the grid bars gradually decreases.

[0012] Furthermore, the grille is fixedly connected to the inner wall of the housing, and the plane where the grille is located is perpendicular to the axis of the main shaft.

[0013] Furthermore, the openings on the helical blades are adapted to the shape and size of the grid, and the helical blades maintain a gap with the grid when rotating to avoid contact.

[0014] Furthermore, the center line of the opening is located in the plane of the grille.

[0015] The beneficial effects of this utility model are as follows:

[0016] This utility model provides a screw conveying device for crushable plate and frame filter cakes. By setting openings on the screw blades and cooperating with a grid fixed to the shell, it achieves efficient crushing of plate and frame filter cakes with a moisture content of 30%-40% during the conveying process, which has significant technical advantages and economic benefits.

[0017] Firstly, this device addresses the stickiness and hardness of high-moisture filter cakes by crushing them through a grid, overcoming the shortcomings of traditional hammer crushers which are ineffective for sticky materials. The filter cake is compressed through the grid by the helical blades, resulting in uniform particle size that meets the requirements of subsequent flash drying or washing processes, significantly improving process efficiency.

[0018] Secondly, the spacing and number of grids can be flexibly adjusted according to the material characteristics. Larger-spacing grids near the feed inlet achieve primary crushing, while smaller-spacing grids near the discharge outlet perform fine crushing. This progressive crushing design enhances the adaptability of the device, making it suitable for filter cake processing scenarios with varying hardness and particle size requirements. Compared to the limitations of fixed crushing structures in existing technologies, the adjustable design of this invention improves versatility and application scope.

[0019] Third, this utility model integrates conveying and crushing functions, eliminating the need for separate crushing equipment, simplifying the process flow, and reducing equipment investment and maintenance costs. Actual application calculations show that compared to traditional processes, equipment investment costs are significantly reduced, and operating energy consumption is also lower, demonstrating a clear energy-saving and efficiency-enhancing effect.

[0020] Finally, this device features a simple structure, is easy to manufacture and install, and occupies a small area, making it suitable for small and medium-sized production lines in industries such as fly ash resource utilization and chemicals. Its high efficiency and economy provide enterprises with a low-cost, high-efficiency solution, and it has excellent market prospects.

[0021] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0022] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0023] Figure 1 This is a structural diagram of a screw conveyor for a crushable plate and frame filter cake according to the present invention.

[0024] Figure 2 for Figure 1Sectional view A-A'.

[0025] Figure 3 for Figure 1 Sectional view of B-B'.

[0026] Figure 4 for Figure 1 Sectional view along line C-C'.

[0027] Reference numerals: 1-Main shaft; 2-Helical blade; 3-Grid; 4-Opening; 5-Shell. Detailed Implementation

[0028] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0029] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0030] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0031] Example 1

[0032] like Figures 1 to 4As shown, this utility model provides a screw conveyor for crushable plate and frame filter cakes, comprising a housing 5, a main shaft 1 rotatably disposed within the housing 5, screw blades 2 fixed on the main shaft 1, and a drive device (not shown in the figure). The housing 5 is a cylindrical structure made of Q235 steel, with a surface coated with anti-corrosion paint to adapt to chemical production environments. The housing 5 has an inlet and an outlet at both ends for material entry and exit. The drive device includes a motor and a reducer. The motor drives the main shaft 1 to rotate via the reducer. The main shaft 1 rotates at a speed of 20-40 rpm to ensure the stability of conveying and crushing.

[0033] The spiral blade 2 has three openings 4 radially distributed along the axial direction of the main shaft 1, with a spacing of 300-400 mm. Each opening 4 is semi-elliptical in shape, with a major axis diameter of 100 mm and a minor axis radius of 50 mm. A grid 3, made of 304 stainless steel and 5 mm thick, is fixed to the inner wall of the housing 5 within each opening 4. There are three grids 3, fixed to the inner wall of the housing 5 and securely connected by welding. The plane of the grid 3 is perpendicular to the axis of the main shaft 1, and the centerline of the opening 4 coincides with the plane of the grid 3, ensuring that the material is effectively squeezed through the grid 3 during conveying. The spacing between the grid bars of the grid 3 gradually decreases along the conveying direction: the grid bars near the feed inlet have a spacing of 100 mm for primary crushing; the middle section has a spacing of 50 mm; and the grid bars near the discharge outlet have a spacing of 20 mm for fine crushing.

[0034] The opening of the spiral blade 2 is adapted to the shape and size of the grid 3. During rotation, the spiral blade 2 maintains a 5-10 mm gap with the grid 3 to avoid contact friction, reduce wear, and prevent material blockage. The main shaft 1 is machined from 45# steel, has a diameter of 80 mm, and is chrome-plated to improve wear resistance. The spiral blade 2 has a pitch of 300 mm, a thickness of 6 mm, and is made of Q235 steel.

[0035] In this embodiment, the device is applied to a fly ash resource utilization process to process plate and frame filter cakes with a moisture content of approximately 35%. During operation, the filter cake enters the housing 5 through the feed inlet and moves along the spiral conveyor channel under the push of the spiral blades 2. The filter cake is crushed into larger particles upon passing through the first grid, then further crushed through the intermediate grid, and finally passes through the grid near the discharge outlet to form uniform particles with a size of 10-20 mm, which are then discharged from the discharge outlet. The crushed filter cake directly enters a three-stage washing tank.

[0036] Example 2

[0037] The difference between this embodiment and Embodiment 1 lies in the slight adjustments to the structural parameters and application scenarios of the device to adapt to different material characteristics. The material of the shell 5 is upgraded to 316L stainless steel to withstand more corrosive chemical environments. The rotational speed of the main shaft 1 is adjusted to 30-60 rpm, suitable for filter cakes with a slightly higher moisture content (approximately 38%). The spiral blades 2 have three openings 4 with a spacing of 200-250 mm, and the opening size is adjusted to 80 mm × 40 mm. The grid spacing of the grid 3 is 30 mm, 20 mm, and 15 mm from the inlet to the outlet, respectively. There are three grids 3, made of high-strength wear-resistant alloy steel, with a tungsten carbide coating to further enhance wear resistance.

[0038] In this embodiment, the device is used in a chemical plant to process plate and frame filter cake containing acidic components. After passing through a three-stage grid, the filter cake is broken into particles of 8-12 mm, meeting the requirements of subsequent water washing processes.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A screw conveying device for crushable plate and frame filter cake, comprising a housing and a main shaft rotatably disposed within the housing, and screw blades fixedly disposed on the main shaft, characterized in that: The spiral blade has an opening along its radial direction, and a grid fixed inside the shell is provided in the opening. The grid divides the conveying channel formed by the spiral blade into segments. The conveyed cake-shaped material is squeezed through the grid during the conveying process, thereby achieving crushing.

2. The screw conveyor device for crushable plate and frame filter cake according to claim 1, characterized in that: The openings are distributed in multiple ways along the main axis.

3. The screw conveyor for crushable plate and frame filter cake according to claim 2, characterized in that: The housing is provided with a feed inlet and a discharge outlet. Along the axial direction of the main shaft, the gap between the grid bars of the grid near the feed inlet is greater than the gap between the grid bars of the grid near the discharge outlet.

4. The screw conveyor for crushable plate and frame filter cake according to claim 3, characterized in that: From the inlet to the outlet, the gap between the grid bars gradually decreases.

5. The screw conveyor device for crushable plate and frame filter cake according to claim 1, characterized in that: The grille is fixedly connected to the inner wall of the housing, and the plane of the grille is perpendicular to the axis of the main shaft.

6. The screw conveyor for crushable plate and frame filter cake according to claim 1, characterized in that: The openings on the helical blades are adapted to the shape and size of the grid, and the helical blades maintain a gap with the grid when rotating to avoid contact.

7. The screw conveyor for crushable plate and frame filter cake according to claim 1, characterized in that: The centerline of the opening is located in the plane of the grille.

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