A new double-deck roller cross screen

Abstract

This invention relates to the field of coal washing equipment technology and discloses a novel double-layer roller cross screen, solving the problems mentioned in the background art. It includes an upper screening unit, a lower screening unit, a support frame, and a drive system. The upper screening unit includes an upper drive frame and an upper roller screen assembly, which consists of multiple upper screen shafts, with adjacent upper screen shafts forming upper screen gaps. The lower screening unit is located below the upper screening unit and includes a lower drive frame and a lower cross screen assembly, which consists of multiple lower screen shafts. Each lower screen shaft is equipped with multiple screen plates, which interlock and form moving screen gaps, the size of which is smaller than the upper screen gaps. The drive system drives the upper and lower screen shafts to rotate in the same direction. This double-layer roller cross screen has low manufacturing cost, small footprint, high screening efficiency, and strong material adaptability, making it particularly suitable for the efficient grading and separation of sticky and wet coal.

Description

Technical Field

[0001] This invention belongs to the technical field of coal washing and beneficiation equipment, specifically a novel double-layer roller cross screen. Background Technology

[0002] Currently, in the coal washing industry, double-layer tensioned screens are commonly used to separate sticky and wet materials from large coal pieces. The working process is as follows: material enters the upper layer of the tensioned screen, where large pieces are first separated; sticky and wet materials smaller than 10 mm enter the lower layer. Through the alternating opening and closing motion of the lower screen, a 50g acceleration is transmitted to the material, causing rapid stratification. Material smaller than the screen openings passes through the openings and enters the lower chute, while material larger than the screen openings is discharged from another chute.

[0003] However, in practical applications, existing tension screens occupy a large plant area, have high manufacturing costs, short screen lifespan, and time-consuming and labor-intensive screen replacement; they are also difficult to integrate with other equipment, especially since many coal preparation plants now use intelligent sorting processes, which require pre-sorting equipment at the front end, making it difficult for tension screens to be effectively integrated with intelligent sorting machines. Summary of the Invention

[0004] To address the problems mentioned in the background art, the present invention provides the following technical solution: a novel double-layer roller cross screen, comprising an upper screening unit, a lower screening unit, a support frame, and a drive system. The upper screening unit consists of an upper drive frame and multiple parallel upper screen shafts, with upper screen gaps formed between adjacent screen shafts, constituting an upper roller screen assembly. The lower screening unit is located below it and consists of a lower drive frame and multiple parallel lower screen shafts. Each lower screen shaft is equipped with multiple screen plates along its axial direction. The screen plates of adjacent lower screen shafts interlock and mesh, forming a moving screen gap smaller than the upper screen gaps in the interlocking area, constituting a lower cross screen assembly. Both screening units are mounted on the support frame and the drive system drives the upper and lower screen shafts to rotate in the same direction.

[0005] Furthermore, elliptical screen plates are installed on the upper screen shaft. The elliptical screen plates of adjacent screen shafts are loosely meshed. When the upper screen shaft rotates, the movement trajectory of the elliptical screen plates forms a sine wave, which pushes the upper material to produce up-and-down movement.

[0006] Furthermore, the size of the upper screen opening is 20 to 100 mm, and the size of the moving screen opening is less than 6 mm.

[0007] Furthermore, the drive system includes a motor, a reducer, and a gearbox. The output shaft of the gearbox is connected to the upper screen shaft via a flexible coupling, and multiple upper screen shafts share a single gearbox for transmission.

[0008] Furthermore, the moving screen gap is formed by screen plates on two adjacent lower screen shafts in the intersecting area. When the two adjacent lower screen shafts rotate, the screen plates on both sides of the moving screen gap move in opposite directions, forming a rubbing-hand structure, which is used to achieve forced screening of fine-grained materials.

[0009] Furthermore, a bushing is provided between adjacent screen plates on the same lower screen shaft, and the bushing and the blocky material above it form a relative movement to remove wet and sticky powder adhering to the side of the screen plate in real time.

[0010] Furthermore, the supporting frame is made of H-beams, including upper beams, lower beams, and columns connecting the two, which are combined to form a hexagonal frame structure.

[0011] Furthermore, a baffle is provided between the upper screening unit and the lower screening unit. The baffle is set along the material flow direction to guide the undersize material screened by the upper screening unit into the feed end of the lower screening unit.

[0012] Furthermore, the upper screening unit is equipped with a feed box at the feed end, and the two screening units are respectively covered by a feed end cover, a middle cover, and a discharge end cover.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] By employing a double-layer structure, the upper roller screen first separates coarse materials, effectively reducing the screening burden on the lower cross screen and preventing material accumulation. Overall screening efficiency and processing capacity are superior to single-layer screens. The upper roller screen utilizes the sinusoidal trajectory generated by the rotation of elliptical screen plates to cause the material on the screen to undulate, achieving agitation and loosening. The lower cross screen uses the interlocking of screen plates on adjacent screen shafts to form a moving screen gap, achieving forced screening of fine-grained materials through a mechanical "hand-rubbing" method, significantly improving screening accuracy. When processing sticky and wet materials, the upper screen surface can pre-screen out coarse materials, preventing them from adhering and clogging the lower screen surface, thus reducing the likelihood of screen clogging. The relative movement between the bushings of the coaxial screen plates and the lumpy materials forms a self-cleaning system, which can remove wet and sticky powder adhering to the sides of the screen plates in real time, ensuring the screening effect of wet and sticky materials. For materials containing many impurities, the double-layer structure can also better withstand impacts. Attached Figure Description

[0015] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 This is a schematic diagram of the upper screening unit structure of the present invention;

[0018] Figure 3 This is a schematic diagram of the lower screening unit structure of the present invention.

[0019] In the diagram: 1. Upper screening unit; 101. Upper drive frame; 102. Upper roller screen assembly; 1021. Upper screen shaft; 1022. Elliptical screen plate; 103. Upper screen slot; 2. Lower screening unit; 201. Lower drive frame; 202. Lower cross screen assembly; 2021. Lower screen shaft; 2022. Screen plate; 2023. Bushing; 203. Moving screen slot; 3. Support frame; 301. Upper crossbeam; 302. Lower crossbeam; 303. Column; 4. Drive system; 401. Motor; 402. Reducer; 403. Gearbox; 404. Flexible coupling; 5. Baffle; 6. Feed box; 7. Feed end cover; 8. Intermediate cover; 9. Discharge end cover; 10. Discharge flange. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] This embodiment provides a novel double-layer roller cross screen, including an upper screening unit 1, a lower screening unit 2, a support frame 3, and a drive system.

[0022] The upper screening unit 1 includes an upper drive frame 101 and an upper roller screen assembly 102 mounted on the upper drive frame 101. The upper roller screen assembly 102 is composed of multiple parallel upper screen shafts 1021, and upper screen gaps 103 are formed between adjacent upper screen shafts 1021. The lower screening unit 2 is located below the upper screening unit 1. The lower screening unit 2 includes a lower drive frame 201 and a lower cross screen assembly 202 mounted on the lower drive frame 201. The lower cross screen assembly 202 is composed of multiple parallel lower screen shafts 2021. Multiple screen plates 2022 are mounted axially on each lower screen shaft 2021. The screen plates 2022 between adjacent lower screen shafts 2021 interlock and mesh with each other, forming a moving screen gap 203 in the interlocking area. The size of the moving screen gap 203 is smaller than the size of the upper screen gap 103. Both the upper screening unit 1 and the lower screening unit 2 are mounted on the support frame 3. The drive system is used to drive the upper screen shaft 1021 and the lower screen shaft 2021 to rotate in the same direction.

[0023] This embodiment provides a novel double-layer roller cross screen, in which the upper roller screen assembly 102 first separates the coarse material, and then the lower cross screen assembly 202 performs fine classification on the undersize material, realizing the separation of multiple particle sizes in one screening, and has a compact structure and occupies a small factory area.

[0024] Elliptical screen plates 1022 are installed on the upper screen shaft 1021. The elliptical screen plates 1022 on adjacent upper screen shafts 1021 are loosely engaged. When the upper screen shaft 1021 rotates, the motion trajectory of the elliptical screen plates 1022 forms a sine wave, which causes the upper material to undulate. As a result, the upper material is fully disturbed and loosened during its forward movement, which helps to improve the screening efficiency.

[0025] The upper screen slit 103 has a size of 20 to 100 mm, while the moving screen slit 203 has a size of less than 6 mm. By differentiating the sizes of the upper and lower screen slits, three types of products—large materials, medium-sized materials, and fine-sized materials—can be separated in one pass.

[0026] The drive system 4 includes a motor 401, a reducer 402 and a gearbox 403. The output shaft of the gearbox 403 is driven by the upper screen shaft 1021 through a flexible coupling 404. Multiple upper screen shafts 1021 share a set of gearbox 403 for transmission. This transmission method can ensure that each upper screen shaft 1021 operates synchronously, and requires less torque and has low energy consumption.

[0027] The moving screen gap 203 is formed by screen plates 2022 located on two adjacent lower screen shafts 2021 in an interlaced area. When the two adjacent lower screen shafts 2021 rotate, the screen plates 2022 on both sides of the moving screen gap 203 move in opposite directions locally, forming a rubbing-hand-like structure to achieve forced screening of fine particles. This structure allows wet, sticky fine particles to be effectively squeezed under the screen, avoiding screen clogging.

[0028] A bushing 2023 is provided between adjacent screen plates 2022 on the same lower screen shaft 2021. The bushing 2023 and the blocky material above it form a relative movement to remove wet and sticky powder adhering to the side of the screen plate 2022 in real time. This constitutes a material self-cleaning system, further ensuring the continuous screening effect of wet and sticky materials.

[0029] The supporting frame 3 is constructed of H-beams and includes an upper crossbeam 301, a lower crossbeam 302, and columns 303 connecting the upper and lower crossbeams 301 and 302. The upper crossbeam 301, lower crossbeam 302, and columns 303 combine to form a hexagonal frame structure. This frame structure has good overall stability and can effectively bear the operating load of the upper and lower screening units.

[0030] A baffle 5 is provided between the upper screening unit 1 and the lower screening unit 2. The baffle 5 is set along the material flow direction to guide the undersize material screened by the upper screening unit 1 into the feed end of the lower screening unit 2. Through the guidance of the baffle 5, it can be ensured that all the undersize material of the upper layer enters the lower screen surface and avoid material spillage.

[0031] The upper screening unit 1 has a feed box 6 at its inlet end. The upper screening unit 1 and the lower screening unit 2 are respectively covered by an inlet end cover 7, a middle cover 8, and a discharge end cover 9. The lower screening unit 2 has a discharge flange 10 at its end, and an under-screen chute and a discharge chute below it. The installation of these covers creates a closed screening environment, preventing dust from escaping. The under-screen chute and discharge chute collect fine and medium-sized particles respectively, achieving effective product diversion.

[0032] Working principle:

[0033] First, the material enters the screen surface of the upper screening unit 1 through the upper feed box 6. Driven by the motor 401 and the reducer 402, the upper screen shafts 1021 rotate synchronously through the gearbox 403 and the flexible coupling 404. The rotation of the elliptical screen plates 1022 generates a sinusoidal trajectory, causing the material on the screen to undulate and loosen. As the material moves forward, it continuously stratifies and passes through the screen. Large pieces of material larger than 30 mm are discharged through the discharge port below the upper discharge end cover 9 and enter the lump coal bin; materials smaller than 30 mm are guided onto the screen surface of the lower screening unit 2 through the baffle 5.

[0034] Then, the lower screening unit 2 arranges all the lower screen shafts 2021 along the coal flow direction on the fixed lower drive frame 201. All the lower screen shafts 2021 rotate in the same direction towards the discharge end, driving the incoming material smaller than 30 mm to move in front of the screen and realizing the projection and stratification of the material. The screen plates 2022 between adjacent lower screen shafts 2021 interlock and mesh with each other, forming a moving screen gap 203 that achieves forced screening of fine particles smaller than 6 mm in a mechanical "rubbing" manner. Fine particles smaller than 6 mm fall into the under-screen chute and enter the pulverized coal bin. At the same time, the relative movement between the bushing 2023 and the lumpy material creates a self-cleaning effect, removing the wet and sticky powder adhering to the side of the screen plate 2022 in real time. Medium-sized particles from 6 mm to 30 mm continue to move forward, are discharged through the discharge chute, and enter the clean coal bin.

[0035] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0036] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A new double-decked roller cross screen, characterized in that, include: The upper screening unit (1) includes an upper drive frame (101) and an upper roller screen assembly (102) mounted on the upper drive frame (101). The upper roller screen assembly (102) is composed of multiple parallel upper screen shafts (1021), and upper screen gaps (103) are formed between adjacent upper screen shafts (1021). The lower screening unit (2) is located below the upper screening unit (1). The lower screening unit (2) includes a lower drive frame (201) and a lower cross screen assembly (202) mounted on the lower drive frame (201). The lower cross screen assembly (202) is composed of multiple parallel lower screen shafts (2021). Each lower screen shaft (2021) has multiple screen plates (2022) mounted axially. The screen plates (2022) between adjacent lower screen shafts (2021) interlock and form a moving screen gap (203) in the interlocking area. The size of the moving screen gap (203) is smaller than the size of the upper screen gap (103). The upper screening unit (1) and the lower screening unit (2) are both installed on the support frame (3). The drive system (4) is used to drive the upper screen shaft (1021) and the lower screen shaft (2021) to rotate in the same direction.

2. A new type of double deck roller cross screen as claimed in claim 1, wherein: Elliptical screen plates (1022) are installed on the upper screen shaft (1021). The elliptical screen plates (1022) on adjacent upper screen shafts (1021) are in a loosely meshed state. When the upper screen shaft (1021) rotates, the motion trajectory of the elliptical screen plates (1022) forms a sine wave, which is used to make the upper material undulate.

3. A new type of double decker roller cross screen as claimed in claim 1, wherein: The size of the upper screen slot (103) is 20 to 100 mm, and the size of the moving screen slot (203) is less than 6 mm.

4. A new type of double deck roller cross screen as claimed in claim 1, wherein: The drive system (4) includes a motor (401), a reducer (402) and a gearbox (403). The output shaft of the gearbox (403) is driven to the upper screen shaft (1021) through a flexible coupling (404), and multiple upper screen shafts (1021) share a set of gearbox (403) for transmission.

5. A new type of double decker roller cross screen as claimed in claim 1, wherein: The moving screen gap (203) is formed by screen plates (2022) located on two adjacent lower screen shafts (2021) in an interlaced area. When the two adjacent lower screen shafts (2021) rotate, the screen plates (2022) on both sides of the moving screen gap (203) move in opposite directions, forming a rubbing-hand structure to achieve forced screening of fine-grained materials.

6. A new type of double-decker roller cross screen according to claim 5, characterized in that: A bushing (2023) is provided between adjacent screen plates (2022) on the same lower screen shaft (2021). The bushing (2023) and the blocky material above it form a relative movement to remove wet and sticky powder adhering to the side of the screen plate (2022) in real time.

7. A new type of double decker roller cross screen as claimed in claim 1, wherein: The supporting frame (3) is made of H-beams and includes an upper beam (301), a lower beam (302) and a column (303) connecting the upper beam (301) and the lower beam (302). The upper beam (301), the lower beam (302) and the column (303) are combined to form a hexagonal frame structure.

8. A new type of double decker roller cross screen as claimed in claim 1, wherein: A baffle (5) is provided between the upper screening unit (1) and the lower screening unit (2). The baffle (5) is arranged along the material flow direction to guide the undersize material screened by the upper screening unit (1) into the feed end of the lower screening unit (2).

9. A new type of double decker roller cross screen as claimed in claim 1, wherein: The upper screening unit (1) is provided with a feed box (6) at the feed end. The upper screening unit (1) and the lower screening unit (2) are respectively covered with a feed end cover (7), a middle cover (8) and a discharge end cover (9); the lower screening unit (2) is provided with a discharge flange (10) at the end.

10. Coal preparation plant, characterized in that, Including the novel double-layer roller cross screen as described in any one of claims 1 to 9.

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