Cylinder screen

Abstract

The utility model relates to a drum screen, and belongs to the field of screening equipment. The structure comprises a feeder (1), a screen drum (4) and a rack (2), and further comprises a hollow rotating table (3) and a screen cage (5), the hollow rotating table (3) is rotationally arranged on the rack (2), one end of the screen drum (4) is connected with the hollow rotating table (3), the screen cage (5) is arranged in the screen drum (4), and the discharging end of the feeder (1) is arranged in a feeding port of the end, close to the hollow rotating table (3), of the screen cage (5). According to the structure, large-size materials are preferentially and independently screened out through the inner-layer screen cage (5) by arranging the screen cages (5), the screening process of the materials with the sizes similar to those of the screen holes (41) is prevented from being interfered, and the screening efficiency can be remarkably improved. The problems that an existing common drum screen is low in screening efficiency, large in appearance size and narrow in application range are solved.

Description

A cylindrical sieve Technical Field

[0001] This utility model relates to a cylindrical screen, belonging to the field of screening equipment. Background Technology

[0002] Screening is a common process in industrial production and has a wide range of applications. Vibrating screens are widely criticized for their high failure rate, such as screen hole jamming, high noise, broken wires, and screen plate cracking. People tend to prefer using cylindrical screens.

[0003] The cylindrical sieve disclosed in Chinese patent ZL202122181294.0 has the advantages of low noise, no sieve jamming, and low failure rate. However, its disadvantages are also obvious: due to the use of a single sieve cylinder, the screening efficiency is low, that is, the screening penetration is poor, the oversize material contains a large amount of unscreened material, and the hourly output is low, making it only suitable for small-scale screening (such as sample classification). In order to increase the production capacity of the cylindrical sieve, a structure with a large diameter (more than 1m), a long sieve cylinder (more than 5m), and supports at both ends is usually adopted, resulting in a large space occupation, high initial investment, and difficult maintenance and repair, making it unsuitable for many occasions. Summary of the Invention

[0004] The technical problem to be solved by this utility model is that existing ordinary cylindrical screens have low screening efficiency, large size, and narrow range of application.

[0005] The technical solution adopted by this utility model to solve its technical problem is: a cylindrical screen, including a feeder, a screen cylinder and a frame, and also including a hollow rotating table and a screen cage. The hollow rotating table is rotatably mounted on the frame, one end of the screen cylinder is connected to the hollow rotating table, the screen cage is set inside the screen cylinder, and the discharge end of the feeder is placed in the feed inlet of the screen cage near the end of the hollow rotating table.

[0006] The hollow rotary table in the above-mentioned device includes a motor and a reducer. The output shaft of the motor is connected to the input shaft of the reducer. The reducer is a hollow worm gear reducer, and the output end of the reducer is connected to the screen cylinder.

[0007] In the aforementioned device, the sieve cylinder is inclined downward away from the hollow rotating platform, and the angle between the axis of the sieve cylinder and the horizontal line is 3 to 6 degrees.

[0008] The sieve cylinder in the above-mentioned device is provided with sieve holes on its side wall. The sieve holes are conical countersunk holes, with the larger end located inside the sieve cylinder.

[0009] Furthermore, in the above-mentioned device, the total area of ​​the sieve holes is greater than 40% of the area of ​​the side wall of the sieve cylinder, and the circumferential arrangement is such that the conical guide surfaces of two adjacent sieve holes are tangent, and the transverse arrangement is such that the hole spacing is the same as the circumferential hole spacing, with adjacent sieve holes staggered and evenly distributed.

[0010] In the aforementioned device, a collector for undersize material is provided at the lower end of the screen cylinder, and a collector for oversize material is provided at the end of the screen cylinder away from the hollow rotating table.

[0011] In the aforementioned device, at least one turbulence column is provided on the inner wall of the feed end of the screen cylinder.

[0012] The screen cage in the above-mentioned device includes a contact ring, a connecting ring, and grate bars. The contact ring and the connecting ring are spaced apart, and the grate bars are spaced apart in a circle, with their two ends connected to the opposite end faces of the contact ring and the connecting ring, respectively.

[0013] Furthermore, in the above-mentioned device, the screen cylinder connection end is connected to the hollow rotary table via a flange, and the connecting ring is a flange structure, and the connecting ring is located at the end away from the hollow rotary table, so that the screen cage is connected to the screen cylinder via the connecting ring.

[0014] Furthermore, in the above-mentioned device, the minimum distance between two adjacent grate bars is greater than 1.5 times the diameter of the large end of the sieve hole.

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

[0016] (1) Large-sized materials are preferentially screened out separately by the inner screen cage to avoid interfering with the screening process of materials with similar screen hole size, which can significantly increase screening efficiency.

[0017] (2) A turbulence column was added to break up materials stuck together by burrs, which can increase screening efficiency.

[0018] (3) Because the screen holes are equipped with conical guide holes, materials with similar sizes to the screen holes can be quickly guided into place, increasing the screening probability. At the same time, the conical section is equivalent to increasing the draft angle of the screen holes, which is conducive to the material being ejected and eliminates the phenomenon of the screen holes getting stuck.

[0019] (4) Due to the increased density of sieve openings per unit area, the chance of sieving increases, significantly increasing sieving efficiency. The cantilever structure with a fixed sieving length of 600mm simplifies the structure and increases mechanical reliability.

[0020] (5) Improved screening efficiency, miniaturized cylindrical screen, less space occupied, lower investment, and can be applied to more production occasions. Attached Figure Description

[0021] Figure 1 is a cross-sectional structural diagram of this utility model.

[0022] Figure 2 is a schematic diagram of the CC cross-section structure of the present invention as shown in Figure 1.

[0023] Figure 3 is a schematic diagram of the sieve structure of this utility model.

[0024] Figure 4 is a structural schematic diagram of the hollow rotary table of this utility model.

[0025] Figure 5 is a schematic diagram of the structure of the sieve cage of this utility model.

[0026] Figure 6 is a schematic diagram of the sieve hole arrangement of this utility model.

[0027] In the diagram: 1. Feeder; 2. Frame; 3. Hollow rotary table; 4. Screen cylinder; 41. Screen hole; 5. Screen cage; 51. Connecting ring; 52. Grate bar; 53. Contact ring; 6. Undersize collector; 7. Oversize collector; 8. Turbulence column; 9. Motor; 10. Reducer. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings.

[0029] As shown in Figures 1 to 6, this utility model discloses a cylindrical screen, including a feeder 1, a screen cylinder 4, and a frame 2. It also includes a hollow rotating platform 3 and a screen cage 5. The hollow rotating platform 3 is rotatably mounted on the frame 2. One end of the screen cylinder 4 is connected to the hollow rotating platform 3. The screen cage 5 is disposed inside the screen cylinder 4, and the discharge end of the feeder 1 is placed in the inlet of the screen cage 5 near the hollow rotating platform 3. Those skilled in the art will understand that in existing screening equipment, before the material is fully screened, large-sized oversize material travels together with unscreened material. The large-sized oversize material occupies the screen openings throughout the process, leaving insufficient contact between small-sized undersize material and the screen openings 41, resulting in low screening efficiency. This device, by placing the screen cage 5 inside the screen cylinder 4 and placing the discharge end of the feeder 1 in the inlet of the screen cage 5 near the hollow rotating platform 3, allows the material to be pre-screened by the screen cage 5 before entering the screen cylinder 4, achieving the purpose of grading and screening through the screen cage 5. This structural design allows materials much larger than the screen aperture 41 to be diverted separately and drawn out from the screen cage 5, not participating in the fine screening process of the screen cylinder 4, and not competing for the aperture space of small-sized materials, thus significantly improving screening permeability. Furthermore, numerous experiments have shown that the screening efficiency of the cylindrical screen does not increase significantly after the screening section length exceeds 600mm. Therefore, with a very dense screen aperture 41, the rigidity of the screen cylinder 4 is weakened, making it unsuitable for being very long and thick, nor suitable for a two-end support method. This device rotatably mounts the hollow rotary table 3 on the frame 2. The feeder 1 is also mounted on the frame 2, uniformly feeding the granular material into the screen cage 5. One end of the screen cylinder 4 is connected to the hollow rotary table 3, making the entire screen cylinder 4 cantilevered and fixed, driven by the hollow rotary table 3. The optimal screening length is 600mm, and the screen cylinder 4 is preferably made of aluminum alloy to reduce its mass.

[0030] Preferably, the hollow rotary table 3 in the above-mentioned device includes a motor 9 and a reducer 10. The output shaft of the motor 9 is connected to the input shaft of the reducer 10. The reducer 10 is a hollow worm gear reducer, and the output end of the reducer 10 is connected to the screen cylinder 4. Those skilled in the art will understand that this device preferably consists of a reducer 10 and a motor 9, and more preferably, the reducer 10 is a hollow worm gear reducer, resulting in high integration, good lubrication, and reliable operation of the hollow rotary table 3.

[0031] Preferably, in the above-mentioned device, the screen cylinder 4 is inclined downwards away from the hollow rotating table 3, and the angle between the axis of the screen cylinder 4 and the horizontal line is 3-6°. Those skilled in the art will understand that, to ensure convenient material discharge, this device preferably has the screen cylinder 4 inclined downwards away from the hollow rotating table 3. Furthermore, since the axes of the feeder 1 and the screen cylinder 4 are collinear, they are both installed inclined downwards on the frame 2, forming a certain angle with the horizontal plane. Based on experience, any value between 3 and 6° is generally used. If the angle is too large, the material rolls too fast, which is not conducive to thorough screening. If the angle is too small, the screening capacity is reduced. A 4° inclination angle is usually preferred.

[0032] Preferably, the screen cylinder 4 in the above-mentioned device is provided with screen holes 41 on its side wall. The screen holes 41 are conical countersunk holes, with the larger end located inside the screen cylinder 4. Those skilled in the art will understand that the existing screen hole 41 has an unreasonable shape and lacks an inlet guide. The most difficult materials to screen are often those whose size is close to that of the screen hole 41. Due to the similar size, the chance of the material falling directly into the screen hole 41 is small. Therefore, it is preferable that the screen hole 41 is a conical countersunk hole, and a conical guide section is provided near the inner side of the screen cylinder 4. For example, if the wall thickness of the screen cylinder 4 is 4mm, a 3×45° chamfer can be provided as a guide, allowing materials with a size close to that of the screen hole 41 to be smoothly introduced into the screen hole 41, increasing the screening probability. When the screen hole 41, along with the stuck material, rotates to the top, it falls under the pull-out force of gravity. The conical surface is equivalent to the screen hole 41 having a certain draft angle, making it easy for the material to escape and less likely to jam the screen hole 41.

[0033] Preferably, in the above-mentioned device, the total area of ​​the screen holes 41 is greater than 40% of the area of ​​the side wall of the screen cylinder 4, and the circumferential arrangement is such that the conical guide surfaces of two adjacent screen holes 41 are tangent, and the transverse arrangement is such that the hole spacing is the same as the circumferential hole spacing, with adjacent screen holes 41 staggered and evenly distributed. Those skilled in the art will understand that existing screen holes 41 are sparsely distributed, resulting in a low density of screen holes 41 per unit area of ​​the screen surface, leading to insufficient opportunities for material to contact the screen holes 41. To achieve a more dense distribution of screen holes 41, the circumferential arrangement should be based on the principle that the conical guide surfaces of two adjacent holes are nearly tangent, and the transverse arrangement should be based on the principle that the hole spacing is the same as the circumferential hole spacing, with adjacent rings of holes staggered. This results in a uniform distribution of screen holes 41 across the entire screen surface, maximizing the area ratio of screen holes 41. Ideally, the area ratio of screen holes 41 should be increased to 40%, while the area ratio of screen holes 41 in ordinary cylindrical screens is 20%, and in general vibrating screens it is >30%.

[0034] Preferably, in the above-mentioned device, an undersize collector 6 is provided at the lower end of the screen cylinder 4, and an oversize collector 7 is provided at the end of the screen cylinder 4 away from the hollow rotating table 3. Those skilled in the art will understand that, for the convenience of collecting the screened material, this device preferably provides an undersize collector 6 at the lower end of the screen cylinder 4 and an oversize collector 7 at the end of the screen cylinder 4 away from the hollow rotating table 3. When the motor 9 of the hollow rotating table 3 is actually started, the screen cylinder 4 rotates, and the material is first separated from the screen cage 5 into undersize A and oversize B. Undersize A falls into the screen cylinder 4 and is graded into undersize C and oversize D by the screen holes 41. Undersize collector 6 guides C to the next process, and oversize collector 7 guides B and D to the next process.

[0035] Preferably, at least one baffle column 8 is provided on the inner wall of the feed end of the screen cylinder 4 in the above-mentioned device. Those skilled in the art will understand that during actual screening, some materials have burrs, causing small particles to adhere to larger particles. The burrs are interlocked and sticky, making them difficult to disperse and resulting in incomplete screening. Furthermore, the outer layer of material has more contact with the screen holes 41, while the inner layer of material has less contact with the screen holes 42. Even without burr adhesion, a thick material layer must be broken up; otherwise, it will not be screened through. Therefore, this device provides at least one baffle column 8 on the inner wall of the front section of the screen cylinder 4 to disperse the material, facilitating thorough screening and improving screening efficiency. For ease of installation, one or more baffle columns 8 can be installed inside the front screen holes 41; preferably, the baffle column 8 is prismatic in shape.

[0036] Preferably, the screen cage 5 in the above-mentioned device includes a contact ring 53, a connecting ring 51, and grate bars 52. The contact ring 53 and the connecting ring 51 are spaced apart, and the grate bars 52 are circumferentially spaced, with both ends connected to the opposite end faces of the contact ring 53 and the connecting ring 51, respectively. Those skilled in the art will understand that, in order to quickly divert larger-sized materials, this device preferably has a screen cylinder 4 structure, specifically including a contact ring 53, a connecting ring 51, and grate bars 52, with the contact ring 53 and the connecting ring 51 spaced apart, and the grate bars 52 circumferentially spaced, with both ends connected to the opposite end faces of the contact ring 53 and the connecting ring 51, respectively.

[0037] Preferably, in the above-mentioned device, the connecting end of the screen cylinder 4 is connected to the hollow rotating table 3 via a flange, and the connecting ring 51 is a flange structure, located at the end away from the hollow rotating table 3, so that the screen cage 5 is connected to the screen cylinder 4 via the connecting ring 51. Those skilled in the art will understand that, for ease of installation and fixing, this device preferably connects the connecting end of the screen cylinder 4 to the hollow rotating table 3 via a flange, and the connecting ring 51 is a flange structure, so that the other end of the screen cylinder 4 can be fastened to the screen cage 5 with bolts via the flange, placing the screen cage 5 inside the screen cylinder 4. Simultaneously, the preload of the connecting threads between the screen cylinder 4 and the hollow rotating table 3 can directly press the contact ring 53 of the screen cage 5 against the end face of the hollow rotating table 3 to achieve a seal.

[0038] Preferably, the minimum distance between two adjacent grate bars 52 in the above-mentioned device is greater than 1.5 times the diameter of the large end of the screen hole 41. Those skilled in the art will understand that, in order to quickly divert larger-sized materials and avoid interfering with the fine screening process inside the screen cylinder 4, the minimum distance between two adjacent grate bars 52 is preferably greater than 1.5 times the diameter of the large end of the screen hole 41, specifically 1.53 times, 1.54 times, or 2 times.

Claims

1. A drum screen comprising a feeder (1), a screen drum (4) and a frame (2), characterized in that: It also includes a hollow rotary table (3) and a screen cage (5). The hollow rotary table (3) is rotatably mounted on the frame (2). One end of the screen cylinder (4) is connected to the hollow rotary table (3). The screen cage (5) is set inside the screen cylinder (4), and the discharge end of the feeder (1) is placed in the feed inlet of the screen cage (5) near the hollow rotary table (3).

2. A cylinder screen according to claim 1, characterized in that: The hollow rotary table (3) includes a motor (9) and a reducer (10). The output shaft of the motor (9) is connected to the input shaft of the reducer (10). The reducer (10) is a hollow worm gear reducer, and the output end of the reducer (10) is connected to the screen cylinder (4).

3. A cylindrical sieve according to claim 1, characterized in that: The sieve cylinder (4) is inclined downward away from the hollow rotating table (3), and the angle between the axis of the sieve cylinder (4) and the horizontal line is 3 to 6 degrees.

4. A cylinder screen according to claim 1, characterized in that: The sieve cylinder (4) has sieve holes (41) on its side wall. The sieve holes (41) are conical sink holes, with the larger end located inside the sieve cylinder (4).

5. A cylinder screen according to claim 4, characterised in that: The total area of ​​the sieve holes (41) is greater than 40% of the side wall area of ​​the sieve cylinder (4), and the circumferential arrangement is such that the conical guide surfaces of two adjacent sieve holes (41) are tangent, and the transverse arrangement is such that the hole spacing is the same as the circumferential hole spacing, and the adjacent sieve holes (41) are staggered and evenly distributed.

6. A cylindrical sieve according to claim 1, characterized in that: The screen cylinder (4) is provided with a screen under collector (6) at the lower end, and the screen over collector (7) is provided at the end of the screen cylinder (4) away from the hollow rotating table (3).

7. A cylindrical sieve according to claim 1, characterized in that: At least one turbulence column (8) is provided on the inner wall of the feed end of the screen cylinder (4).

8. A cylindrical sieve according to claim 1, characterized in that: The screen cage (5) includes a contact ring (53), a connecting ring (51) and a grate bar (52). The contact ring (53) and the connecting ring (51) are spaced apart, and the grate bar (52) is circumferentially spaced apart, with its two ends connected to the opposite end faces of the contact ring (53) and the connecting ring (51) respectively.

9. A cylindrical sieve according to claim 8, characterized in that: The screen cylinder (4) is connected to the hollow rotating table (3) via a flange. The connecting ring (51) is a flange structure and is located at the end away from the hollow rotating table (3), so that the screen cage (5) is connected to the screen cylinder (4) via the connecting ring (51).

10. A cylindrical sieve according to claim 8, characterized in that: The minimum spacing between two adjacent grate bars (52) is 1.5 times the diameter of the large end of the sieve hole (41).

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