Oil-rich pulverized coal fine grinding and screening device and method

Abstract

The invention discloses an oil-rich pulverized coal fine grinding and screening device and method, and belongs to the technical field of oil-rich pulverized coal processing. The fine grinding and screening device for the oil-rich pulverized coal comprises a rack, a shell and a connecting shaft, and further comprises a cylindrical filter screen, wherein a gap is reserved between the cylindrical filter screen and the inner wall of the shell; the grinding part comprises two grinding mechanisms, each grinding mechanism comprises a grinding ring, a grinding wheel and a driving mechanism, the grinding rings are arranged at one end of the cylindrical filter screen, ring holes of the grinding rings communicate with ring holes of the cylindrical filter screen, the driving mechanisms are connected with the grinding wheels, and the driving mechanisms are used for driving the grinding wheels to axially roll on the inner walls of the grinding rings around the connecting shafts; the outer wall of the annular scraper is attached to the inner wall of the cylindrical filter screen; the reciprocating driving mechanism is used for driving the annular scraper to reciprocate in the axial direction of the connecting shaft. According to the fine grinding and screening device for the oil-rich pulverized coal, in the fine grinding and screening process of the oil-rich pulverized coal, the problem that the screening net is blocked due to the viscosity of the oil-rich pulverized coal can be solved, and the operation stability of equipment is improved.

Description

Technical Field

[0001] This invention relates to the field of oil-rich pulverized coal processing technology, specifically to a fine grinding and screening device and method for oil-rich pulverized coal. Background Technology

[0002] Oil-rich coal, as a high-quality energy resource with high oil content and outstanding conversion value, has broad application prospects in fields such as chemical raw materials and clean fuels. Its large-scale, efficient utilization is of great significance in alleviating the contradiction between energy supply and demand. Fine grinding and screening are the core pretreatment steps in the deep processing of oil-rich coal, requiring the coal to be refined to a uniform particle size to provide high-quality raw materials for subsequent conversion processes such as dry distillation and gasification. In the field of oil-rich pulverized coal processing and utilization, the grinding fineness and screening purity of the pulverized coal directly determine the subsequent oil extraction efficiency and product quality.

[0003] In the current field of fine grinding and screening of oil-rich pulverized coal, the traditional combined process of "fine grinding equipment + screening equipment" or integrated simple screening and grinding devices are commonly used. Among them, the fine grinding equipment is mostly conventional grinding equipment such as ball mills and Raymond mills, while the screening equipment is mainly linear vibrating screens and circular vibrating screens. The core working logic is: after being ground by the fine grinding equipment, the oil-rich pulverized coal directly enters the screening equipment for particle size classification. The qualified fine powder is collected, and the unqualified coarse powder is returned to the fine grinding equipment for re-grinding.

[0004] However, due to its high oil content, oil-rich pulverized coal is prone to adsorption and agglomeration after grinding, forming sticky granular clumps. During screening, these clumps not only have difficulty passing through the screen mesh but also tend to adhere to the screen surface, accumulating over time and gradually causing blockage. Blockage leads to a sharp decline in screening efficiency and a significant reduction in the yield of qualified fine powder, requiring frequent shutdowns for screen cleaning and increasing labor costs. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems in the prior art and provide a fine grinding and screening device for oil-rich pulverized coal, which can prevent the screening screen from clogging due to the high viscosity of oil-rich pulverized coal during the fine grinding and screening process.

[0006] This invention provides a fine grinding and screening device for oil-rich pulverized coal, comprising a frame, a housing, and a connecting shaft. The connecting shaft is connected to the frame, and the housing is coaxially arranged with the connecting shaft and rotatably connected to it. The device also includes: A cylindrical filter screen is disposed inside the housing and fixed to the inner wall of the housing. The cylindrical filter screen is coaxially arranged with the housing, and a gap is left between the cylindrical filter screen and the inner wall of the housing. Two grinding mechanisms are located at both ends of the cylindrical filter screen. The two grinding mechanisms have the same structure, each including a grinding ring, a grinding wheel and a driving mechanism. The grinding ring is located at one end of the cylindrical filter screen. The grinding surface of the inner wall of the grinding ring is conical. The large end of the grinding surface is connected to the annular hole of the cylindrical filter screen. The driving mechanism is connected to the grinding wheel and is used to drive the grinding wheel to roll axially around the connecting shaft on the inner wall of the grinding ring. An annular scraper is disposed within the annular holes of a cylindrical filter screen, and the outer wall of the annular scraper is in contact with the inner wall of the cylindrical filter screen. A reciprocating drive mechanism is connected to the inner wall of the annular scraper. The reciprocating drive mechanism is used to drive the annular scraper to reciprocate along the axial direction of the connecting shaft, thereby scraping off the coal dust adhering to the cylindrical filter screen and pushing it into the annular hole of the grinding ring.

[0007] Preferably, the reciprocating drive mechanism includes a limiting strip, a reciprocating screw, and a reciprocating sleeve. The limiting strip is disposed on the inner wall of the cylindrical filter screen, and the length direction of the limiting strip is parallel to the axial direction of the connecting shaft. The outer wall of the annular scraper is provided with a limiting groove, and the annular scraper is slidably connected to the limiting strip through the limiting groove. The limiting strip and the limiting groove are used to prevent the annular scraper from rotating relative to the cylindrical filter screen. The connecting shaft is fixedly connected to the reciprocating screw and is coaxially arranged and fixedly connected. The reciprocating sleeve is connected to the reciprocating screw, and the annular scraper is fixedly connected to the reciprocating sleeve.

[0008] Preferably, the annular scraper is provided with a plurality of brushes, which are evenly distributed along the circumference of the cylindrical filter screen, and each brush is in contact with the inner wall of the cylindrical filter screen.

[0009] Preferably, the annular scraper is provided with a plurality of sliding holes, which are evenly distributed along the circumference of the cylindrical filter screen. The axial direction of each sliding hole is along the radial direction of the cylindrical filter screen. A sliding rod is fixedly connected to each brush, and each sliding rod corresponds to a sliding hole. Each sliding rod is slidably connected to the corresponding sliding hole along the axial direction of the corresponding sliding hole. A spring is provided outside the sliding rod, and the spring abuts against the brush. The spring is used to apply an elastic force toward the inner wall of the cylindrical filter screen to the brush.

[0010] Preferably, the drive mechanism includes a planetary gear system and a wheel carrier. The sun gear of the planetary gear system is fixedly connected to the side wall of the housing and is coaxially arranged with the connecting shaft. The planet carrier of the planetary gear system is fixedly connected to the connecting shaft. The gear ring of the planetary gear system is coaxially arranged with the connecting shaft and is fixedly connected to the wheel carrier. The wheel carrier is rotatably connected to the connecting shaft. Multiple grinding wheels are rotatably connected on the wheel carrier, and the outer wall of each grinding wheel abuts against the inner wall of the grinding ring.

[0011] Preferably, a plurality of support bars are fixedly connected to the housing, the plurality of support bars are evenly distributed along the circumference of the cylindrical filter screen, each support bar abuts against the outer wall of the cylindrical filter screen, the support bars are used to apply a supporting force toward the axis of the cylindrical filter screen, and each limiting bar is fixedly connected to a support bar.

[0012] Preferably, the inner diameter of the grinding ring is smaller than the inner diameter of the cylindrical filter screen.

[0013] Preferably, the annular scraper has an annular groove structure, and multiple brushes are disposed in the annular groove on the annular scraper.

[0014] Preferably, the material of the annular filter screen is alloy steel.

[0015] The present invention also provides a fine grinding and screening method for an oil-rich pulverized coal fine grinding and screening device, comprising the following steps: The drive housing rotates, which in turn drives the cylindrical filter screen to rotate, causing large pieces of pulverized coal inside the cylindrical filter screen to spread to both ends of the cylindrical filter screen. As the cylindrical filter screen rotates, the reciprocating drive mechanism drives the annular scraper to push the large pieces of pulverized coal into the grinding mechanism at both ends. The drive mechanism drives the grinding wheel to roll axially around the connecting shaft on the inner wall of the grinding ring, thereby initially grinding large pieces of pulverized coal into small particles; As the grinding ring rotates, the pre-ground pulverized coal enters the annular holes of the cylindrical filter screen; The shell drives the cylindrical filter screen to rotate synchronously. Under the action of centrifugal force, fine coal particles that meet the fineness requirements enter the gap between the cylindrical filter screen and the inner wall of the shell through the mesh of the cylindrical filter screen, and are finally discharged from the shell feed port. Substandard coarse-particle coal remains inside the cylindrical filter screen and continues to rotate; The double drive mechanism drives the annular scraper to reciprocate along the connecting shaft. The annular scraper scrapes off the coal clumps adhering to the inner wall of the cylindrical filter screen and pushes the scraped coal clumps to the grinding mechanisms at both ends for secondary fine grinding. After secondary grinding, the coal clumps re-enter the cylindrical filter screen for screening.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: In the fine grinding and screening device for oil-rich pulverized coal of the present invention, the grinding mechanism at both ends of the cylindrical filter screen grinds large pulverized coal particles. As the grinding ring of the grinding mechanism rotates, the pulverized coal particles that have been initially ground in the ring holes of the grinding ring will diffuse into the ring holes of the cylindrical filter screen. Fine pulverized coal particles that meet the fineness requirements enter the gap between the filter screen and the inner wall of the shell through the mesh of the cylindrical filter screen, and are finally discharged from the feed port at the bottom of the shell. After coal clumps adhere to the inner wall of the cylindrical filter screen, the reciprocating drive mechanism drives the annular scraper to move axially along the connecting shaft when blocking the mesh of the cylindrical filter screen. This completely scrapes off the adhered coal clumps, preventing the mesh from becoming blocked. At the same time, the reciprocating motion of the annular scraper not only generates axial thrust on the coarse coal particles in the annular holes of the cylindrical filter screen, pushing them to the grinding mechanisms at both ends for secondary fine grinding, but also pushes the coal clumps formed on the cylindrical filter screen to the grinding mechanisms at both ends for further grinding. The ground coal then re-enters the cylindrical filter screen for screening, forming a "grinding-screening-unblocking-re-grinding" cycle until all the coal reaches the required fineness and is discharged. This significantly improves the grinding fineness and uniformity of the oil-rich coal. The synergistic effect of the annular scraper and the reciprocating drive mechanism solves the problem of screen blockage caused by the stickiness of the oil-rich coal, improving the stability of equipment operation. The pushing action of the scraper enables coarse pulverized coal and coal lumps adhering to the filter screen to undergo secondary grinding, avoiding raw material waste while achieving a gradient processing of "coarse grinding - fine grinding" and improving the compliance rate of pulverized coal fineness.

[0017] The cooperation between the limiting strip and the limiting groove ensures the smooth movement of the annular scraper, ensuring precise contact between the outer wall of the annular scraper and the inner wall of the cylindrical filter screen, thus improving the removal effect of the annular scraper on the coal clumps adhering to the inner wall of the cylindrical filter screen. The reciprocating screw and reciprocating sleeve can drive the annular scraper to reciprocate along the axial direction of the cylindrical filter screen without the need for additional power components, thereby improving the reliability of the entire device under harsh working conditions. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the external structure of the present invention. Figure 2 This is a schematic diagram of the internal structure of the first embodiment of the present invention; Figure 3 This is a schematic diagram of the internal structure of the second embodiment of the present invention; Figure 4 for Figure 3 Schematic diagram of the structure of surface AA; Figure 5 for Figure 3 Schematic diagram of the structure of the middle BB surface; Figure 6 for Figure 3 Schematic diagram of the structure of the C-plane; Figure 7 This is a schematic diagram of the structure of the brush part of the present invention; Figure 8 This is a schematic diagram of the drive mechanism of the present invention.

[0019] Explanation of reference numerals in the attached figures: 101. Frame; 102. Housing; 103. Connecting shaft; 104. Cylindrical filter screen; 105. Gap; 106. Grinding ring; 107. Grinding wheel; 108. Drive mechanism; 109. Annular scraper; 110. Reciprocating drive mechanism; 201. Limiting bar; 202. Reciprocating lead screw; 203. Reciprocating threaded sleeve; 3. Brush; 401. Slide rod; 402. Spring; 501. Wheel frame; 502. Sun gear; 503. Gear ring; 504. Planetary carrier; 601. Support bar; 7. Annular groove. Detailed Implementation

[0020] The following is in conjunction with the appendix Figures 1-8 The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0021] like Figure 1 , Figure 2 , Figure 6 and Figure 8As shown, the present invention provides a fine grinding and screening device for oil-rich pulverized coal, comprising a frame 101, a housing 102, and a connecting shaft 103. The connecting shaft 103 is connected to the frame 101. The housing 102 is coaxially arranged with the connecting shaft 103 and is rotatably connected to the connecting shaft 103. A power device is connected to the housing 102, which drives the housing 102 to rotate around the connecting shaft 103. The device also includes a cylindrical filter screen 104, an annular scraper 109, a reciprocating drive mechanism 110, and two grinding mechanisms. The cylindrical filter screen 104 is disposed inside the housing 102 and fixedly connected to the inner wall of the housing 102. The cylindrical filter screen 104 is coaxially arranged with the housing 102, and a gap 105 is left between the cylindrical filter screen 104 and the inner wall of the housing 102. The two grinding mechanisms are respectively disposed at both ends of the cylindrical filter screen 104. The two grinding mechanisms have the same structure, each including a grinding ring 106 and a grinding wheel. The filter includes a grinding wheel 107 and a drive mechanism 108. The grinding ring 106 is located at one end of the cylindrical filter screen 104. The grinding surface of the inner wall of the grinding ring 106 is conical, and the large end of the grinding surface communicates with the annular hole of the cylindrical filter screen 104. The drive mechanism 108 is connected to the grinding wheel 107 and is used to drive the grinding wheel 107 to roll axially around the connecting shaft 103 on the inner wall of the grinding ring 106. An annular scraper 109 is located in the annular hole of the cylindrical filter screen 104, and the outer wall of the annular scraper 109 is in contact with the inner wall of the cylindrical filter screen 104. A reciprocating drive mechanism 110 is connected to the inner wall of the annular scraper 109 and is used to drive the annular scraper 109 to reciprocate along the axial direction of the connecting shaft 103, thereby scraping off the coal dust adhering to the cylindrical filter screen 104 and pushing it into the annular hole of the grinding ring 106.

[0022] The working principle of the above embodiments is briefly described below: The shell 102 has a feed inlet on its side wall and the cylindrical filter screen 104, through which oil-rich coal raw material can be added into the annular holes of the cylindrical filter screen 104. A power unit is connected to the outside of the shell 102 via an external gear ring 503. Two identical grinding mechanisms are installed at both ends of the cylindrical filter screen 104. The annular holes of the grinding rings 106 of each grinding mechanism are connected to the annular holes of the cylindrical filter screen 104. The grinding wheels 107, driven by the drive mechanism 108, are in contact with the inner wall of the grinding rings 106, forming a double-end grinding unit. An annular scraper 109 is placed inside the annular holes of the cylindrical filter screen 104, with its outer wall tightly fitted to the inner wall of the filter screen. The inner wall is connected to the reciprocating drive mechanism 110, allowing it to reciprocate along the connecting shaft 103.

[0023] During formal processing, oil-rich pulverized coal enters the annular holes of the cylindrical filter screen 104 through the feed inlet. As the power unit drives the housing 102 to rotate, the housing 102 drives the cylindrical filter screen 104 to rotate, causing the raw material entering the annular holes of the cylindrical filter screen 104 to spread out to both ends of the cylindrical filter screen 104, thus allowing it to enter the grinding mechanisms located at both ends of the cylindrical filter screen 104. The drive mechanism 108 drives the grinding wheel 107 to roll axially around the connecting shaft 103 on the inner wall of the grinding ring 106. Through the squeezing and shearing action between the grinding wheel 107 and the grinding ring 106, large pieces of pulverized coal are initially ground into small particles. As the grinding ring 106 rotates, the conical grinding surface guides the pulverized coal being ground. The pulverized coal slowly moves towards the cylindrical filter screen 109 along the conical grinding surface until it is discharged from the grinding ring 106 into the cylindrical filter screen 109. At this time, the shell 102 drives the cylindrical filter screen 104 to rotate synchronously. Under the action of centrifugal force, fine pulverized coal particles that meet the fineness requirements pass through the mesh of the cylindrical filter screen 104 and enter the gap 105 between the cylindrical filter screen 104 and the inner wall of the shell 102, and are finally discharged from the feed port of the shell 102, completing the screening process. At the same time, it also makes room for the next feeding of the grinding ring 106, avoiding fine powder occupying the space of the grinding mechanism, which would prevent coarse particles from completely entering the grinding mechanism. Coarse pulverized coal particles that do not meet the standards cannot pass through the mesh and continue to rotate with the cylindrical filter screen 104 inside the cylindrical filter screen 104.

[0024] During the screening process, the oil in the oil-rich pulverized coal can easily cause the pulverized coal particles to clump together and adhere to the inner wall of the cylindrical filter screen 104, resulting in mesh blockage and affecting screening efficiency. At this time, the reciprocating drive mechanism 110 is activated, driving the annular scraper 109 to reciprocate along the connecting shaft 103 (the reciprocating frequency can be adjusted according to the blockage situation). The tight fit between the outer wall of the annular scraper 109 and the inner wall of the cylindrical filter screen 104 allows the annular scraper 109 to completely scrape off the coal clumps adhering to the inner wall of the cylindrical filter screen 104 when it reciprocates along the axial direction of the connecting shaft 103, preventing the coal clumps from covering the mesh of the cylindrical filter screen 104. At the same time, the reciprocating motion of the annular scraper 109 between the two grinding mechanisms also generates an axial thrust on the coarse coal particles in the annular holes of the cylindrical filter screen 104, pushing them to the grinding mechanisms at both ends of the cylindrical filter screen 104 for secondary fine grinding. The coal after secondary grinding re-enters the cylindrical filter screen 104 for screening, forming a cyclic processing flow of "grinding-screening-unblocking-re-grinding" until all the coal reaches the fineness requirements and is discharged.

[0025] The oil-rich pulverized coal fine grinding and screening device of the present invention, through the design of "double-end grinding + circulating screening", significantly improves the grinding fineness and uniformity of oil-rich pulverized coal, laying a high-quality raw material foundation for subsequent oil extraction processes. The synergistic effect of the annular scraper 109 and the reciprocating drive mechanism 110 can solve the problem of mesh blockage during the grinding and screening process of oil-rich pulverized coal, improving the operational stability of the equipment. The pushing action of the annular scraper 109 enables secondary grinding of coarse pulverized coal particles and coal lumps adhering to the cylindrical filter screen 104, avoiding raw material waste while realizing "coarse grinding-fine grinding" gradient processing, improving the compliance rate of pulverized coal fineness.

[0026] Based on the above embodiments, in order to ensure that the outer wall of the annular scraper 109 is precisely fitted with the inner wall of the cylindrical filter screen 104, and to improve the removal effect of the annular scraper 109 on the coal dust adhering to the inner wall of the cylindrical filter screen 104.

[0027] like Figures 3-5 and Figure 8 As shown, the reciprocating drive mechanism 110 includes a limiting strip 201, a reciprocating screw 202, and a reciprocating sleeve 203. The limiting strip 201 is disposed on the inner wall of the cylindrical filter screen 104, and the length direction of the limiting strip 201 is parallel to the axial direction of the connecting shaft 103. The outer wall of the annular scraper 109 is provided with a limiting groove, and the annular scraper 109 is slidably connected to the limiting strip 201 through the limiting groove. The limiting strip 201 and the limiting groove are used to prevent the annular scraper 109 from rotating relative to the cylindrical filter screen 104. The connecting shaft 103 is fixedly connected to the reciprocating screw 202 and is coaxially arranged and fixedly connected. The reciprocating sleeve 203 is connected to the reciprocating screw 202, and the annular scraper 109 is fixedly connected to the reciprocating sleeve 203.

[0028] The housing 102 drives the cylindrical filter screen 104 to rotate relative to the connecting shaft 103. The cylindrical filter screen 104 drives the annular scraper 109 to rotate relative to the connecting shaft 103 through the limiting strip 201 and the limiting groove. This drives the reciprocating sleeve 203 to rotate relative to the reciprocating screw 202 fixed to the connecting shaft 103. Under the driving force of the reciprocating screw 202, the reciprocating sleeve 203 makes a smooth reciprocating motion along the axial direction of the cylindrical filter screen 104, thereby driving the annular scraper 109 to move synchronously. The cooperation between the limiting strip 201 and the limiting groove ensures the smoothness of the movement of the annular scraper 109 and ensures that the outer wall of the annular scraper 109 is precisely fitted with the inner wall of the cylindrical filter screen 104, thereby improving the removal effect of the annular scraper 109 on the coal dust adhering to the inner wall of the cylindrical filter screen 104. The reciprocating screw 202 and reciprocating sleeve 203 can drive the annular scraper 109 to reciprocate along the axial direction of the cylindrical filter screen 104 without the need for additional power components, thereby improving the reliability of the entire device under harsh working conditions.

[0029] As a preferred option, such as Figure 3 , Figure 5 and Figure 7 As shown, the annular scraper 109 is equipped with multiple brushes 3, which are evenly distributed along the circumference of the cylindrical filter screen 104. Each brush 3 is in contact with the inner wall of the cylindrical filter screen 104. While the annular scraper 109 reciprocates along the axial direction of the cylindrical filter screen 104, the brushes 3 move synchronously with the annular scraper 109. Since the cylindrical filter screen 104 also rotates relative to the annular scraper 109, the brushes 3 rotate relative to the cylindrical filter screen 104. The brushes 3 can sweep the entire inner wall of the cylindrical filter screen 104, achieving dual cleaning of the inner wall of the cylindrical filter screen 104. The brushes 3 can penetrate deep into the mesh holes blocked by fine coal dust, thoroughly removing the accumulated material. For the material accumulated at the edges of the mesh holes that the annular scraper 109 cannot reach, the cleaning effect is significantly improved compared to the simple scraper, reducing the impact of mesh blockage on screening efficiency from the root cause and ensuring a smooth cycle of "grinding-screening-unblocking-re-grinding".

[0030] As a preferred option, such as Figure 5 As shown, the annular scraper 109 is provided with multiple sliding holes, which are evenly distributed along the circumference of the cylindrical filter screen 104. The axial direction of each sliding hole is along the radial direction of the cylindrical filter screen 104. Each brush 3 is fixedly connected to a sliding rod 401, and each sliding rod 401 corresponds to a sliding hole. Each sliding rod 401 is slidably connected to the corresponding sliding hole along the axial direction of the corresponding sliding hole. A spring 402 is provided outside the sliding rod 401. The spring 402 abuts against the brush 3 and is used to apply an elastic force toward the inner wall of the cylindrical filter screen 104 to the brush 3. The slide rod 401 is made of 304 stainless steel and forms a clearance fit with the sliding hole on the annular scraper 109. The clearance is controlled at 0.03-0.05mm to ensure that the slide rod 401 slides smoothly and without jamming along the radial direction of the cylindrical filter screen 104. The spring 402 is a cylindrical helical compression spring with a stiffness of 1-2N / mm. After being sleeved on the outside of the slide rod 401, one end abuts against the brush 3 and the other end abuts against the annular scraper 109. In the initial state, a radial elastic force of 10-20N is applied to the brush 3 to ensure that the brush 3 is tightly attached to the inner wall of the cylindrical filter screen 104. If there is slight deformation, local protrusion, or thick coal seam accumulation on the inner wall of the cylindrical filter screen 104, or if the brush 3 is worn, the slide rod 401 can flexibly extend and retract along the radial direction of the sliding hole. The spring 402 adjusts the pressure on the brush 3 in real time through elastic deformation, so that the brush 3 is always tightly attached to the inner wall of the cylindrical filter screen 104, avoiding cleaning dead corners and ensuring stable cleaning effect. Even under complex working conditions, it can effectively prevent the mesh of the cylindrical filter screen 104 from clogging and ensure that the screening efficiency does not decrease.

[0031] As a preferred option, such as Figures 2-4 , Figure 6 and Figure 8As shown, the drive mechanism 108 includes a planetary gear system and a wheel carrier 501. The sun gear 502 of the planetary gear system is fixedly connected to the side wall of the housing 102 and is coaxially arranged with the connecting shaft 103. The planet carrier 504 of the planetary gear system is fixedly connected to the connecting shaft 103, and the gear ring 503 of the planetary gear system is coaxially arranged with the connecting shaft 103 and is fixedly connected to the wheel carrier 501. The wheel carrier 501 is rotatably connected to the connecting shaft 103. Multiple grinding wheels 107 are rotatably connected to the wheel carrier 501. The outer wall of each grinding wheel 107 abuts against the inner wall of the grinding ring 106. Three to four grinding wheels 107 are evenly distributed circumferentially on the wheel carrier 501. The contact pressure between each grinding wheel 107 and the inner wall of the grinding ring 106 is adjusted to 3-5 kN to ensure uniform distribution of grinding force. The rotation of the housing 102 synchronously drives the sun gear 502 to rotate, which in turn drives the planetary gears to rotate around their own axes. Since the planet carrier 504 of the planetary gear system is fixedly connected to the connecting shaft 103, the planetary gears do not revolve around the sun gear 502. The planetary gears drive the gear ring 503 to rotate around the connecting shaft 103, which in turn drives the gear carrier 501 to rotate around the connecting shaft 103. Multiple grinding wheels 107 on the gear carrier 501 roll along the inner wall of the grinding ring 106. This transmission design allows the grinding wheels 107 to roll along the inner wall of the grinding ring 106 without relying on additional power components, thereby improving the reliability of the entire device. Simultaneously, the evenly distributed design of the multiple grinding wheels 107 increases the uniformity of force on the inner wall of the grinding ring 106 by 50%, avoiding uneven wear of the grinding ring 106 due to excessive localized force, ensuring stable grinding results, and further improving the fineness and uniformity of pulverized coal grinding.

[0032] As a preferred option, such as Figure 5 As shown, a plurality of support bars 601 are fixedly connected to the housing 102. The support bars 601 are evenly distributed along the circumference of the cylindrical filter screen 104. Each support bar 601 abuts against the outer wall of the cylindrical filter screen 104. The support bars 601 are used to apply a supporting force toward the axis of the cylindrical filter screen 104. Each limiting bar 201 is fixedly connected to one support bar 601. The housing 102 drives the support bars 601 to rotate synchronously. The support bars 601 continuously apply a uniform supporting force toward the axis of the cylindrical filter screen 104, counteracting the expansion effect of centrifugal force on the cylindrical filter screen 104, and preventing the cylindrical filter screen 104 from deforming or shifting due to long-term high-speed rotation or impact of pulverized coal. This prevents the annular scraper 109 from being stuck by the inner wall of the cylindrical filter screen 104 or from scratching the inner wall of the cylindrical filter screen 104.

[0033] As a preferred option, such as Figures 2-4As shown, the inner diameter of the grinding ring 106 is smaller than the inner diameter of the cylindrical filter screen 104. This smaller inner diameter allows the pulverized coal, which is thoroughly ground within the grinding ring 106, to gradually spread into the cylindrical filter screen 104 during the rotation of the grinding ring 106.

[0034] As a preferred option, such as Figure 3 , Figure 5 and Figure 7 As shown, the annular scraper 109 has an annular groove structure, and multiple brushes 3 are disposed in the annular groove 7 on the annular scraper 109. The annular scraper 109 reciprocates along the axial direction, and the brushes 3 in the annular groove 7 simultaneously clean the inner wall of the cylindrical filter screen 104. The structure of the annular groove 7 can protect the brushes 3, preventing them from bending or falling off due to impact from pulverized coal or collision with hard impurities during the cleaning process.

[0035] As a preferred option, such as Figures 2-5 As shown, the material of the annular filter screen 104 is alloy steel. The high tensile strength of alloy steel ensures that the annular filter screen 104 does not undergo plastic deformation under high-speed rotation (15-30 r / min) and centrifugal force, further preventing the annular scraper 109 from getting stuck.

[0036] The present invention also provides a fine grinding and screening method for an oil-rich pulverized coal fine grinding and screening device, comprising the following steps: The drive housing 102 rotates, which in turn drives the cylindrical filter screen 104 to rotate, causing large pieces of pulverized coal inside the cylindrical filter screen 104 to spread to both ends of the cylindrical filter screen 104. As the cylindrical filter screen 104 rotates, the reciprocating drive mechanism 110 drives the annular scraper 109 to push the large pieces of pulverized coal into the grinding mechanism at both ends. The drive mechanism 108 drives the grinding wheel 107 to roll axially around the connecting shaft 103 on the inner wall of the grinding ring 106, thereby initially grinding large pieces of coal into small particles; As the grinding ring 106 rotates, the pre-ground pulverized coal enters the annular holes of the cylindrical filter screen 104; The shell 102 drives the cylindrical filter screen 104 to rotate synchronously. Under the action of centrifugal force, fine coal particles that meet the fineness requirements enter the gap 105 between the cylindrical filter screen 104 and the inner wall of the shell 102 through the mesh, and are finally discharged from the feed port of the shell 102. Non-compliant coarse-particle coal remains inside the cylindrical filter screen 104 and continues to rotate; The reciprocating drive mechanism 110 drives the annular scraper 109 to reciprocate along the connecting shaft 103. The annular scraper 109 scrapes off the coal clumps adhering to the inner wall of the cylindrical filter screen 104 and pushes the scraped coal clumps to the grinding mechanisms at both ends for secondary fine grinding. After secondary grinding, the coal clumps re-enter the cylindrical filter screen 104 for screening.

[0037] 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.

Claims

1. A fine grinding and screening device for oil-rich pulverized coal, comprising a frame, a housing, and a connecting shaft, wherein the connecting shaft is connected to the frame, the housing is coaxially arranged with the connecting shaft, and the housing and the connecting shaft are rotatably connected, characterized in that, Also includes: A cylindrical filter screen is disposed inside the housing and fixed to the inner wall of the housing. The cylindrical filter screen is coaxially arranged with the housing, and a gap is left between the cylindrical filter screen and the inner wall of the housing. Two grinding mechanisms are located at both ends of the cylindrical filter screen. The two grinding mechanisms have the same structure, each including a grinding ring, a grinding wheel and a driving mechanism. The grinding ring is located at one end of the cylindrical filter screen. The grinding surface of the inner wall of the grinding ring is conical. The large end of the grinding surface is connected to the annular hole of the cylindrical filter screen. The driving mechanism is connected to the grinding wheel and is used to drive the grinding wheel to roll axially around the connecting shaft on the inner wall of the grinding ring. An annular scraper is disposed within the annular holes of the cylindrical filter screen, and the outer edge of the annular scraper is in contact with the inner wall of the cylindrical filter screen. A reciprocating drive mechanism is connected to the inner wall of the annular scraper. The reciprocating drive mechanism is used to drive the annular scraper to reciprocate along the axial direction of the connecting shaft, thereby scraping off the coal dust adhering to the cylindrical filter screen and pushing it into the annular hole of the grinding ring.

2. The fine grinding and screening device for oil-rich pulverized coal as described in claim 1, characterized in that, The reciprocating drive mechanism includes a limiting strip, a reciprocating screw, and a reciprocating sleeve. The limiting strip is located on the inner wall of the cylindrical filter screen, and its length direction is parallel to the axial direction of the connecting shaft. The outer wall of the annular scraper is provided with a limiting groove, and the annular scraper is slidably connected to the limiting strip through the limiting groove. The limiting strip and the limiting groove are used to prevent the annular scraper from rotating relative to the cylindrical filter screen. The connecting shaft is fixedly connected to the reciprocating screw and is coaxially arranged and fixedly connected. The reciprocating sleeve is connected to the reciprocating screw, and the annular scraper is fixedly connected to the reciprocating sleeve.

3. The fine grinding and screening device for oil-rich pulverized coal as described in claim 1, characterized in that, The annular scraper is provided with multiple brushes, which are evenly distributed along the circumference of the cylindrical filter screen, and each brush is in contact with the inner wall of the cylindrical filter screen.

4. The fine grinding and screening device for oil-rich pulverized coal as described in claim 3, characterized in that, The annular scraper is provided with multiple sliding holes, which are evenly distributed along the circumference of the cylindrical filter screen. The axial direction of each sliding hole is along the radial direction of the cylindrical filter screen. A sliding rod is fixed to each brush, and each sliding rod corresponds to a sliding hole. Each sliding rod is slidably connected to the corresponding sliding hole along the axial direction of the corresponding sliding hole. A spring is provided outside the sliding rod, and the spring abuts against the brush. The spring is used to apply an elastic force toward the inner wall of the cylindrical filter screen to the brush.

5. The fine grinding and screening device for oil-rich pulverized coal as described in claim 1, characterized in that, The drive mechanism includes a planetary gear system and a wheel carrier. The sun gear of the planetary gear system is fixedly connected to the side wall of the housing and is coaxially arranged with the connecting shaft. The planet carrier of the planetary gear system is fixedly connected to the connecting shaft. The gear ring of the planetary gear system is coaxially arranged with the connecting shaft and is fixedly connected to the wheel carrier. The wheel carrier is rotatably connected to the connecting shaft. Multiple grinding wheels are rotatably connected on the wheel carrier. The outer wall of each grinding wheel abuts against the inner wall of the grinding ring.

6. The fine grinding and screening device for oil-rich pulverized coal as described in claim 2, characterized in that, Multiple support bars are fixedly connected to the housing. The multiple support bars are evenly distributed along the circumference of the cylindrical filter screen. Each support bar abuts against the outer wall of the cylindrical filter screen. The support bars are used to apply a supporting force toward the axis of the cylindrical filter screen. Each limiting bar is fixedly connected to one support bar.

7. The fine grinding and screening device for oil-rich pulverized coal as described in claim 1, characterized in that, The inner diameter of the grinding ring is smaller than the inner diameter of the cylindrical filter screen.

8. The fine grinding and screening device for oil-rich pulverized coal as described in claim 3, characterized in that, The annular scraper has an annular groove structure, and multiple brushes are arranged in the annular groove on the annular scraper.

9. The fine grinding and screening device for oil-rich pulverized coal as described in claim 1, characterized in that, The material of the annular filter screen is alloy steel.

10. A fine grinding and screening method for the oil-rich pulverized coal fine grinding and screening device as described in claim 1, characterized in that, Includes the following steps: The drive housing rotates, which in turn drives the cylindrical filter screen to rotate, causing large pieces of pulverized coal inside the cylindrical filter screen to spread to both ends of the cylindrical filter screen. As the cylindrical filter screen rotates, the reciprocating drive mechanism drives the annular scraper to push the large pieces of pulverized coal into the grinding mechanism at both ends. The drive mechanism drives the grinding wheel to roll axially around the connecting shaft on the inner wall of the grinding ring, thereby initially grinding large pieces of pulverized coal into small particles; As the grinding ring rotates, the pre-ground pulverized coal enters the annular holes of the cylindrical filter screen; The shell drives the cylindrical filter screen to rotate synchronously. Under the action of centrifugal force, fine coal particles that meet the fineness requirements enter the gap between the cylindrical filter screen and the inner wall of the shell through the mesh of the cylindrical filter screen, and are finally discharged from the shell feed port. Substandard coarse-particle coal remains inside the cylindrical filter screen and continues to rotate; The double drive mechanism drives the annular scraper to reciprocate along the connecting shaft. The annular scraper scrapes off the coal clumps adhering to the inner wall of the cylindrical filter screen and pushes the scraped coal clumps to the grinding mechanisms at both ends for secondary fine grinding. After secondary grinding, the coal clumps re-enter the cylindrical filter screen for screening.

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