Equal-thickness screen for coal injection and use method thereof

Abstract

The invention provides an equal-thickness screen for coal injection and a using method thereof, and solves the problem that after raw coal is deslimed, the amount of coal slime mixed in oversize materials and raw coal is too large. The uniform thickness screen comprises a screen box body, a vibration exciter is arranged on the screen box body, a multi-dip-angle screening assembly is arranged in the screen box body, a scrubbing assembly is fixed to the upper side of the middle of the screening assembly and comprises a transverse conical screen frame, the conical screen frame is filled with polyurethane scrubbing bars, and a flushing assembly is arranged above the discharging side of the conical screen frame. The flushing direction of the flushing assembly is opposite to the moving direction of the coal; a feeding chute is arranged at the feeding end of the screening assembly, a stirring assembly is arranged in the feeding chute, and the stirring assembly penetrates through the feeding chute to be connected with the screening box body. According to the invention, the desliming effect is improved, the desliming path is shortened, and the use amount of flushing water in the desliming process is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of equal thickness screens, in particular to an equal thickness screen for pulverized coal injection and a use method thereof. Background Art

[0002] The PCI coal sorting usually adopts the process of pre-de-sliming + pressurized three-product heavy medium cyclone sorting. The raw coal is crushed to less than 50mm, and the 50~0mm raw coal is de-slimed by 1mm using an equal thickness screen to obtain coarse coal slime under the screen and 50~1mm mixed raw coal on the screen. The mixed raw coal on the screen is sorted by a pressurized three-product heavy medium cyclone; the coarse coal slime under the screen is classified by a hydraulic classification cyclone, the bottom flow is 1~0.25mm coarse coal slime, and the overflow is 0.25~0mm fine coal slime, which are processed by a coarse coal slime sorter and a flotation machine respectively.

[0003] When the existing equal-thickness screen is used for 1mm desliming, there is a problem that the amount of coal slime in the mixed raw coal on the screen is too large and the screening efficiency needs to be improved, which will have the following adverse effects: (1) Excessive coal slime enters the heavy medium cyclone along with the mixed raw coal, which will increase the coal slime content in the heavy medium suspension, destroy the stability of the suspension, and make the density control of the suspension more complicated and more difficult to adjust; (2) Coal slime will reduce the density of the suspension, reduce the separation density of the heavy medium cyclone, increase the mismatch of clean coal in the coal and the mismatch of medium coal in the gangue, resulting in a decrease in the yield of clean coal and medium coal; (3) The increase in the amount of coal slime brought in will reduce the removal efficiency of clean coal, medium coal and gangue, increase the medium consumption, and in the subsequent magnetic separation stage, excessive coal slime will also reduce the magnetic separation efficiency and increase the magnetic separation cost.

[0004] In addition, before the 50~0mm raw coal enters the equal-thickness screen, the raw coal is mixed with water in the feeding chute mainly through the impact force of the water flow, and the material is prevented from sinking to the bottom. Due to space limitations in the feeding chute and control of equipment costs and production costs, it is not suitable to increase mechanical stirring, and it mainly relies on the huge impact force of the water flow.

[0005] 50~0mm raw coal is vibrated and deslimed on an equal-thickness screen. Large coal particles move upward, fine coal particles move downward, and coal with a particle size of less than 1mm passes through the screen. In the middle and late stages of desliming of the coal on the screen (desliming is mainly carried out at this stage), fine particles adhere to the surface of large particles, or clumped into a mass, or are at the bottom of the material group on the screen, hindering the contact between the coal with a particle size of less than 1mm and the screen surface. Water flushing from the upper side of the material group on the screen, slowing down the movement of the material group on the screen, and increasing the screening time, the improvement of desliming efficiency is still limited. Summary of the invention

[0006] The present invention provides an equal-thickness screen for blown coal and its usage method, which improves the sludge removal effect, shortens the sludge removal path, and reduces the consumption of flushing water during the sludge removal process.

[0007] The technical solution of the present invention is realized as follows: An equal-thickness screen for blown coal includes a screen box body, an exciter is arranged on the screen box body, and a multi-inclination screening component is arranged inside the screen box body. A scrubbing component is fixed on the upper side of the middle part of the screening component. The scrubbing component includes a horizontal conical mesh frame, and polyurethane scrubbing rods are filled in the conical mesh frame. A flushing component is arranged above the discharging side of the conical mesh frame, and the flushing direction of the flushing component is opposite to the moving direction of the coal material; a feeding chute is arranged at the feeding end of the screening component, a stirring component is arranged in the feeding chute, and the stirring component passes through the feeding chute and is connected to the screen box body.

[0008] Further, the screening component includes multiple longitudinal screen bodies with gradually decreasing inclination angles in sequence. The longitudinal screen body with the smallest inclination angle is the last-stage screen body. A backwashing component is arranged below the middle part of the last-stage screen body. The backwashing component flushes water obliquely upward from the lower side of the last-stage screen body, and the flushing direction is opposite to the moving direction of the coal material.

[0009] Further, the feeding chute includes a feeding section, a premixing section, and a discharging section connected in sequence. A flushing pipe is arranged at the feeding end of the premixing section, and the flushing direction of the flushing pipe is opposite to the moving direction of the raw coal. An overflow baffle is arranged at the discharging end of the premixing section. The stirring component is located in the premixing section. The stirring component is a planar horizontal frame body, and connecting rods are fixed at both ends of the stirring component. Perforations are arranged on the premixing section, and the perforations are higher than the overflow baffle. The connecting rods pass through the perforations and are connected to the screen box body, and rubber sealing plugs are arranged at the perforations.

[0010] Further, the screening component includes a polyurethane flexible frame, which is composed of positioning grooves arranged in a horizontal and vertical array. Screen mesh pieces are clamped in the positioning grooves, and waterproof tapes are bonded at the joints of the upper surfaces of adjacent screen mesh pieces. Compared with large-volume and integrated screen meshes, this structure facilitates the production, transportation, and on-site assembly of the screening component, and also facilitates the replacement of screen mesh pieces in the future.

[0011] Further, support shafts are arranged at intervals along the conveying direction of the coal material inside the screen box body. The height of the support shafts is adjustable. The support shafts are located below the screening component and are used to support the screening component; polyurethane elastic blocks are fixed on both sides inside the screen box body along the conveying direction of the coal material. The lower ends of the polyurethane elastic blocks are in sealing contact with the upper side edges of the screening component. The upper side edges of the screening component are sealed and positioned by the polyurethane elastic blocks to prevent coal sludge from directly passing through the screen without screening through the edges of the screening component.

[0012] A polyurethane flexible frame is adopted to make the adjacent lateral screen sheets flexibly connected. By adjusting the height of the support shaft and the number of support shafts corresponding to each longitudinal screen body, it is convenient to adjust the length and inclination angle of each longitudinal screen body as needed. Although the angle of each longitudinal screen body of the existing equal-thickness screen can be adjusted, the length is mostly fixed, which is not convenient to adjust as needed.

[0013] Furthermore, a screen discharge hopper is arranged below the screening assembly. A fixed shaft is arranged at the upper end of the screen discharge hopper, and the fixed shaft abuts against the lower side of the screening assembly. When the screening assembly vibrates, it collides with the fixed shaft, causing the materials blocked in the screen holes to break away.

[0014] A method for using an equal-thickness screen for pulverized coal injection includes the following steps: (1) The vibrator drives the screen box body and the screening assembly to vibrate. The screen box body drives the stirring assembly to vibrate in the feed chute, so that the raw coal and water are mixed evenly in the feed chute to form a coal slurry. (2) The coal slurry enters the screening assembly for desliming. The oversize materials in the middle of the screening assembly enter the conical screen frame. With the vibration of the screening assembly, the polyurethane scrubbing rods scrub the oversize materials. At the same time, the flushing assembly flushes water in the reverse direction to wipe off the coal slime adhered to the surface of the oversize material particles, making the surface of the oversize material particles smooth. (3) The scrubbed oversize materials continue to be deslimed along the screening assembly.

[0015] Furthermore, in step (3), after the scrubbed oversize materials continue to be deslimed along the screening assembly and enter the middle of the last-stage screen body, the backwashing assembly flushes water obliquely upward from the lower side of the last-stage screen body. The fine-particle oversize materials at the bottom of the upper surface of the last-stage screen body are washed up by the water, opening the particle gaps of the oversize materials. With the subsequent vibration desliming, it is convenient for the coal slime to contact the screen surface through the particle gaps and pass through the screen.

[0016] Furthermore, in step (1), when the raw coal enters the premixing section from the feeding section, the flushing pipe flushes the raw coal in the reverse direction. With the impact force of the water and the vibration and stirring of the stirring assembly, the raw coal and water are mixed evenly to form a coal slurry. The coal slurry overflows through the overflow baffle into the feeding section and then enters the screening assembly through the discharging section.

[0017] Furthermore, in steps (1)-(3), when the screening assembly vibrates, the lower side of the screening assembly collides and vibrates with the fixed shaft, causing the blocked-hole materials to break away from the screen holes of the screening assembly.

[0018] The beneficial effects of the present invention: In the present invention, a scrubbing assembly is added above the middle of the screening assembly. During the process of vibrating and de-sludging the oversize materials, scrubbing is carried out synchronously to break up the agglomerated coal materials, scrub the fine particles adhered to the surface of large particles, remove the adhered coal slime, and at the same time make its surface smooth, reducing the probability of subsequent adhesion of coal slime. In addition, scrubbing rods made of polyurethane material are used and coordinated with the moving speed of the coal materials in the middle of the screening assembly to avoid over-grinding of the coal material particles during scrubbing while ensuring the scrubbing effect.

[0019] In the present invention, a stirring assembly is added to the feed chute. The stirring assembly is connected to the sieve box body and vibrates along with the vibration of the sieve box body, thereby vibrating and stirring the coal slurry in the feed chute. The stirring assembly is a planar horizontal frame body, and stirring is achieved through vibration, with less space requirement for the feed chute and no additional new drive. Through hydraulic impact combined with vibration stirring, it is conducive to the rapid mixing of raw coal and water and reduces the requirement for water impact force.

[0020] In the present invention, a backwashing assembly is added below the middle of the last-stage sieve body, flushing water obliquely from bottom to top to break up the fine particle materials accumulated at the bottom of the material group, facilitating the contact between the coal slime and the sieve surface, and thus facilitating the penetration of the coal slime through the sieve.

[0021] Through the cooperation of the scrubbing assembly and the backwashing assembly, etc., the present invention improves the de-sludging effect and shortens the screening and de-sludging path; compared with flushing from the upper side of the oversize materials during the de-sludging process, the present invention is also conducive to reducing the consumption of flushing water during the de-sludging process. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 It is a schematic structural diagram of Embodiment 1 of the present invention; Figure 2 It is a schematic internal structure diagram of the sieve box body; Figure 3 It is for Figure 2 The partial structural diagram of A in Figure 4 It is a schematic structural diagram of the feed chute; Figure 5 It is a schematic structural diagram of the screening assembly; Figure 6 It is a schematic structural diagram of the positioning groove; Figure 7 It is a schematic structural diagram of Embodiment 3 of the present invention; Figure 8 It is a structural schematic diagram of a polyurethane elastic block; Figure 9 It is a structural schematic diagram of a stirring assembly.

[0024] Screen box body 1, chassis 2, spring seat 3, screen discharge hopper 4, vibrator 5, screening assembly 6, scrubbing assembly 7, conical mesh frame 8, polyurethane scrubbing rod 9, flushing assembly 10, feeding section 11, premixing section 12, flushing water pipe 13, overflow baffle 14, stirring assembly 15, connecting rod 16, perforation 17, final stage screen body 18, backwashing assembly 19, polyurethane flexible frame 20, positioning groove 21, screen mesh 22, waterproof tape 23, support shaft 24, strip hole 25, polyurethane elastic block 26, fixed shaft 27, inner vertical section 28, horizontal section 29, outer vertical section 30, support rod 31. Specific implementation manner

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] Embodiment 1 As Figure 1 and 2 shown, an equal-thickness screen for pulverized coal injection includes a screen box body 1 and a chassis 2, and the screen box body 1 is connected to the chassis 2 through a spring seat 3. A vibrator 5 is installed on the screen box body 1, and a multi-inclination screening assembly 6 is longitudinally arranged in the screen box body 1, and the vibrator 5 drives the screen box body 1 and the screening assembly 6 to vibrate. A screen discharge hopper 4 is arranged below the screening assembly 6, and the screened material enters the screen discharge hopper 4.

[0027] As Figure 2 and 3 shown, a scrubbing assembly 7 is fixed on the upper side of the middle part of the screening assembly 6. The scrubbing assembly 7 vibrates synchronously with the screening assembly 6. The scrubbing assembly 7 includes a horizontal conical mesh frame 8. The conical mesh frame 8 is fixed on the upper side of the middle part of the screening assembly 6. The conical mesh frame 8 is filled with polyurethane scrubbing rods 9. The diameter of the polyurethane scrubbing rods 9 is larger than the aperture of the conical mesh frame 8, and the polyurethane scrubbing rods 9 cannot break away from the conical mesh frame 8. The aperture of the conical mesh frame 8 is larger than the particle size of the raw coal, facilitating the raw coal to pass through the conical mesh frame 8.

[0028] The leading end of the screening component 6 has a relatively large inclination angle, and the moving speed of the coal material is relatively fast. The trailing end has a relatively small inclination angle, and the moving speed of the coal material is relatively slow. The scrubbing component 7 is arranged in the middle of the screening component 6, and the time for the coal material to pass through the conical mesh frame 8 is appropriate. On the one hand, it avoids the too-fast moving speed of the coal material so that it has no time to be fully scrubbed. On the other hand, it also facilitates the coal material to pass through the conical mesh frame 8 at a relatively fast speed and prevents coal material accumulation at the conical mesh frame 8. Using scrubbing rods made of polyurethane material and the relatively fast passing of the coal material through the conical mesh frame 8 can avoid over-grinding of the coal material particles during scrubbing.

[0029] In addition, the oversize materials in the middle of the screening component 6 have been preliminarily screened. The caking of coal slime on the surface of large particles or the agglomeration of fine particle coal slime increases the difficulty of subsequent screening. Through the setting of the scrubbing component 7 at this place, on the one hand, it breaks up the agglomerated fine particle coal slime, and on the other hand, it scrubs the surface of large particles to remove the adhered coal slime, making its surface smooth and reducing the probability of subsequent coal slime adhesion.

[0030] Above the discharge side of the conical mesh frame 8, a flushing component 10 is fixed. The flushing component 10 is a row of horizontally arranged flushing nozzles. The flushing direction of the flushing component 10 is opposite to the moving direction of the coal material, which is convenient for the scrubbed coal slime to be fully mixed with water and enter the undersize.

[0031] As Figure 1 and 4 shown, a feeding chute is arranged at the feeding end of the screening component 6. The feeding chute includes a feeding section 11, a premixing section 12 and a discharging section that are connected in sequence. The opening of the feeding section 11 faces upward, facilitating the entry of raw coal. The opening of the discharging section faces downward and is connected to the upper end of the screening component 6. A flushing water pipe 13 is fixed at the feeding end of the premixing section 12. The flushing direction of the flushing water pipe 13 is opposite to the moving direction of the raw coal. An overflow baffle 14 is fixed at the discharging end of the premixing section 12. After the raw coal is fully mixed with water to form a coal slurry, the coal slurry overflows through the overflow baffle 14 and enters the discharging section, facilitating the horizontal and uniform feeding of the screening component 6.

[0032] As Figure 4 and 9As shown in the figure, the stirring assembly 15 is located within the premixing section 12. The stirring assembly 15 is a planar horizontal frame body. The horizontal frame body includes an outer frame body, and cross bars are fixedly spaced within the outer frame body. Both ends of the stirring assembly 15 are fixedly connected to connecting rods 16. The premixing section 12 is provided with perforations 17, which are higher than the overflow baffle 14. The connecting rod 16 includes an inner vertical section 28. The lower end of the inner vertical section 28 is fixedly connected to the horizontal frame body, and the upper end is fixedly connected to a horizontal section 29. The horizontal section 29 passes through the perforation 17 and is fixedly connected to an outer vertical section 30. The lower end of the outer vertical section 30 is connected to the sieve box body 1 through a support rod 31. A rubber sealing plug is filled at the perforation 17 to prevent leakage of the coal slurry at the perforation 17. The overall size of the raw coal feed hopper is relatively large and high. The feed chute is fixed to the lower end of the feed hopper. The vibratory stirring of the stirring assembly 15 in this embodiment will not affect the feed hopper.

[0033] The sieve box body 1 drives the stirring assembly 15 to vibrate and stir within the premixing section 12 through the connecting rod 16. When the raw coal enters the premixing section 12 through the feed section 11, the flushing pipe 13 flushes the raw coal in the reverse direction. With the impact force of the water and the vibratory stirring of the stirring assembly 15, the raw coal and water are quickly mixed evenly to form coal slurry. The coal slurry overflows through the overflow baffle 14 into the discharge section, and then enters the screening assembly 6 through the discharge section.

[0034] The usage method of the equal-thickness sieve for pulverized coal injection in this embodiment includes the following steps: (1) The vibrator 5 drives the sieve box body 1 and the screening assembly 6 to vibrate. The sieve box body 1 drives the stirring assembly 15 to vibrate within the feed chute, facilitating the quick and even mixing of the raw coal and water within the feed chute to form coal slurry. (2) The coal slurry enters the screening assembly 6 for desliming. The oversize materials in the middle of the screening assembly 6 enter the conical screen frame 8. With the vibration of the screening assembly 6, the polyurethane scrubbing rods 9 scrub the oversize materials, and at the same time, the flushing assembly 10 flushes in the reverse direction to remove the coal slime adhering to the surface of the oversize material particles, making the surface of the oversize material particles smooth. The smooth surface of the particles reduces the probability of subsequent adhesion of coal slime. (3) The scrubbed oversize materials continue to be deslimed along the screening assembly 6.

[0035] Embodiment 2 This embodiment is basically the same as Embodiment 1, except that, as Figure 2 shown, the screening assembly 6 includes multiple longitudinal sieve bodies with gradually decreasing inclination angles. The longitudinal sieve body with the smallest inclination angle is the last-stage sieve body 18. A backwashing assembly 19 is fixedly provided below the middle of the last-stage sieve body 18. The backwashing assembly 19 is a row of flushing nozzles arranged horizontally. The backwashing assembly 19 flushes upward obliquely from the lower side of the last-stage sieve body 18, and the flushing direction is opposite to the moving direction of the coal material.

[0036] If the particle size of the desliming is less than 1 mm, that is, the coal particles less than 1 mm are the undersize materials. With the vibration screening of the coal material, fine particle coal materials such as those with a particle size of 3 mm - 1 mm, or even 5 mm - 3 mm, etc., which are close to the particle size of less than 1 mm, are also likely to become the bottom materials of the oversize materials. This hinders the downward movement of the coal particles less than 1 mm and their contact with the screen surface, thereby reducing the desliming efficiency. Continuing with vibration screening and flushing with water from the upper side has little effect.

[0037] In this embodiment, through the setting of the backwashing component 19, after scrubbing, the oversize materials continue to deslime along the screening component 6. After entering the middle of the last-stage screen body 18, the backwashing component 19 flushes water obliquely upward from the lower side of the last-stage screen body 18. The fine particle oversize materials at the bottom on the upper surface of the last-stage screen body 18 are washed upward by the water, breaking up the accumulation of the bottom fine particle materials, opening the particle gaps of the oversize materials. With subsequent vibration desliming, it is convenient for the coal slime to contact the screen surface through the particle gaps, and thus it is convenient for the coal slime to pass through the screen.

[0038] Embodiment 3 This embodiment is basically the same as Embodiment 1, the difference is that, as Figure 2 、 5 and shown in 6, the screening component 6 includes a polyurethane flexible frame 20. The polyurethane flexible frame 20 is composed of positioning grooves 21 arranged in a transverse and longitudinal array. A screen mesh sheet 22 is clamped in the positioning groove 21. A waterproof tape 23 is bonded at the joint of the upper surfaces of adjacent screen mesh sheets 22. On the one hand, it avoids material jamming at the joint and forms a screening dead angle. On the other hand, it fixes the screen mesh sheet 22 to prevent it from falling out of the positioning groove 21.

[0039] Support shafts 24 are fixedly arranged at intervals along the conveying direction of the coal material in the screen box body 1. As Figure 7 shown, strip-shaped holes 25 corresponding to the support shafts 24 are arranged on the screen box body 1. The ends of the support shafts 24 are bolted to the strip-shaped holes 25. When it is necessary to adjust the height of the support shafts 24, just loosen the bolts. The support shafts 24 are located below the screening component 6 and are used to support the screening component 6. As Figure 2 and 8 shown, polyurethane elastic blocks 26 are fixedly arranged on both sides in the screen box body 1 along the conveying direction of the coal material. The lower ends of the polyurethane elastic blocks 26 are in sealing contact with the upper side edges of the screening component 6. The upper side edges of the screening component 6 are sealed and positioned through the polyurethane elastic blocks 26 to prevent material leakage at the edges of the screening component 6.

[0040] The assembly method of the screening assembly 6 is as follows: the screen sheet 22 is clamped into the positioning groove 21 of the polyurethane flexible frame 20, and then the waterproof tape 23 is bonded at the joints of adjacent screen sheets 22 to obtain an assembled screen body. The screening assembly 6 includes a plurality of longitudinal screen bodies with decreasing inclination angles. According to the longitudinal length and inclination angle of the longitudinal screen body, the number and height of the corresponding support shafts 24 are adjusted, and the assembled screen body is placed on the support shafts 24. Finally, polyurethane elastic blocks 26 are installed at both ends of the upper side of the screen body.

[0041] like Figure 2 As shown, a height-adjustable fixed shaft 27 is installed at the upper end of the under-screen hopper 4. The fixed shaft 27 is staggered with the support shaft 24, and the fixed shaft 27 is against the lower side of the screening component 6. When the screening component 6 vibrates, its lower side collides with the fixed shaft 27, which facilitates the pore-blocking material to escape from the sieve holes of the screening component 6.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An equal-thickness screen for blown coal, comprising a screen box body, an exciter is arranged on the screen box body, and a multi-inclination screening component is arranged longitudinally in the screen box body, and is characterized in that: A scrubbing component is fixed to the upper side of the middle part of the screening component. The scrubbing component includes a horizontal conical mesh frame filled with polyurethane scrubbing rods. Above the discharge side of the conical mesh frame, a flushing component is arranged, and the flushing direction of the flushing component is opposite to the moving direction of the coal material; at the feeding end of the screening component, a feeding chute is arranged, and a stirring component is arranged in the feeding chute. The stirring component passes through the feeding chute and is connected to the sieve box body.

2. The equal-thickness sieve for pulverized coal injection according to claim 1, characterized in that: The screening component includes multiple longitudinal sieve bodies with gradually decreasing inclination angles in sequence. The longitudinal sieve body with the smallest inclination angle is the last-stage sieve body. Below the middle part of the last-stage sieve body, a backwashing component is arranged. The backwashing component flushes water obliquely upward from the lower side of the last-stage sieve body, and the flushing direction is opposite to the moving direction of the coal material.

3. The equal-thickness screen for pulverized coal injection according to claim 1 or 2, characterized in that: The feeding chute includes a feeding section, a premixing section, and a discharging section connected in sequence. At the feeding end of the premixing section, a flushing pipe is arranged, and the flushing direction of the flushing pipe is opposite to the moving direction of the raw coal. At the discharging end of the premixing section, an overflow baffle is arranged. The stirring component is located in the premixing section. The stirring component is a planar horizontal frame body. Connecting rods are fixed to both ends of the stirring component. Perforations are arranged on the premixing section, and the perforations are higher than the overflow baffle. The connecting rods pass through the perforations and are connected to the sieve box body. Rubber sealing plugs are arranged at the perforations.

4. The equal-thickness sieve for pulverized coal injection according to claim 1, wherein: The screening component includes a polyurethane flexible frame composed of positioning grooves arranged in a horizontal and longitudinal array. Sieve mesh sheets are clamped in the positioning grooves, and waterproof tapes are bonded at the joints of the upper surfaces of adjacent sieve mesh sheets.

5. The equal-thickness screen for blown coal according to claim 4, characterized in that: Support shafts are arranged at intervals along the conveying direction of the coal material in the sieve box body. The height of the support shafts is adjustable. The support shafts are located below the screening component and are used to support the screening component; polyurethane elastic blocks are fixed on both sides in the sieve box body along the conveying direction of the coal material. The lower ends of the polyurethane elastic blocks are in sealing contact with the edges of the upper side of the screening component.

6. A constant-thickness screen for blown coal according to claim 1, 4 or 5, characterized in that: A sieve discharge hopper is arranged below the screening component. A fixed shaft is arranged at the upper end of the sieve discharge hopper, and the fixed shaft abuts against the lower side of the screening component.

7. The usage method of the equal-thickness sieve for injection coal according to any one of claims 1-6, characterized in that, It includes the following steps: (1) The vibrator drives the sieve box body and the screening component to vibrate. The sieve box body drives the stirring component to vibrate in the feeding chute, so that the raw coal and water are mixed evenly in the feeding chute to form a coal slurry. (2) The coal slurry enters the screening component for de-sludging. The oversize material in the middle of the screening component enters the conical mesh frame. With the vibration of the screening component, the polyurethane scrubbing rods scrub the oversize material. At the same time, the flushing component flushes water in the reverse direction to wipe off the coal slime adhered to the surface of the oversize material particles, making the surface of the oversize material particles smooth. (3) The scrubbed oversize material continues to be de-sludged along the screening component.

8. The usage method according to claim 7, characterized in that, In step (3), after being scrubbed, the oversize material continues to be de-sludged along the screening component. After entering the middle of the last-stage sieve body, the backwashing component flushes water obliquely upward from the lower side of the last-stage sieve body. The fine particles at the bottom layer on the upper surface of the last-stage sieve body are washed up by the water, opening the particle gaps of the oversize material. With subsequent vibration de-sludging, it is convenient for the coal slime to contact the sieve surface through the particle gaps and pass through the sieve.

9. The method of use according to claim 7, characterized in that In step (1), when the raw coal enters the premixing section through the feeding section, the flushing pipe flushes the raw coal in the reverse direction. With the impact force of the water and the vibration stirring of the stirring component, the raw coal and water are mixed evenly to form a coal slurry. The coal slurry overflows through the overflow baffle into the discharging section and then enters the screening component through the discharging section.

10. The usage method according to claim 7, characterized in that In steps (1)-(3), when the screening component vibrates, the lower side of the screening component collides with the fixed shaft and vibrates, causing the blocked material to break away from the screening holes of the screening component.

Images