Low-quality coal high-precision dry method deashing and upgrading method and process

Abstract

The present application relates to the technical field of coal processing, and particularly relates to a high-precision dry method for deashing and upgrading low-quality coal and a process thereof, comprising the following process steps: S1, conveying and pretreatment; S2, vibration and air blowing; S3, primary screening; S4, secondary screening; S5, dehydration and drying; S6, monitoring and regulation; S7, collection and recovery; comprising a shell and a screw feeder, two vibration motors are symmetrically installed on the shell, two damping bases are symmetrically installed at the bottom end of the shell, and a pretreatment mechanism is arranged on the shell and the screw feeder. The present application can not only preheat and preliminarily crush and separate the coal powder, so as to prepare for the subsequent dehydration and drying process, but also can promote the secondary crushing and separation of the coal powder in the subsequent flow drying process, and separate, discharge and recover the unqualified coal powder and dust in the coal powder, so as to effectively improve the overall quality of the coal powder drying and deashing.

Description

Technical Field

[0001] This invention relates to the field of coal powder processing technology, and in particular to a high-precision dry deashing and upgrading method and process for low-quality coal. Background Technology

[0002] Low-quality coal, while having a significant price advantage compared to common bituminous or anthracite coal, is characterized by high impurity content, high moisture content, and low calorific value. These characteristics not only limit the direct application of low-quality coal but may also significantly reduce combustion efficiency during combustion, leading to energy waste. Therefore, low-quality coal must undergo a drying and deashing process for upgrading before it can be used. Drying and deashing are inseparable in the upgrading process of low-quality coal. Most existing high-precision deashing methods for low-quality coal are dry deashing. Dry deashing mainly uses the vibration of a fluidized bed to separate the coal particles that were originally aggregated, and then uses a blower to dry the coal. The airflow from the blower and the vibration of the fluidized bed further blow away the impurities and dust in the dried low-quality coal, thus completing the upgrading of the low-quality coal.

[0003] However, existing fluidized bed drying methods for low-quality coal mostly rely on simple vibration to break and separate coal particles, resulting in poor separation efficiency. Larger coal agglomerates are difficult to separate completely, leading to insufficient drying of moisture within the agglomerates and thus reducing the quality of dehydration and drying. Furthermore, the presence of agglomerates can easily trap impurities in low-quality coal, and dust may also adhere to the moisture inside, further reducing the overall quality of drying and deashing. Consequently, this significantly reduces the quality of upgrading low-quality coal, making it impractical. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that the separation effect of fluidized bed in the prior art is not good when drying and deashing low-quality coal, thereby reducing the overall quality of low-quality coal drying and deashing. Therefore, this invention proposes a high-precision dry deashing and upgrading method and process for low-quality coal.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A high-precision dry deashing and upgrading process for low-quality coal includes the following steps: S1. Conveying and pretreatment: The heated magnetic powder and the lignite powder to be treated are conveyed to the mixing chamber, and the coal powder is preheated and initially crushed and separated by the heated magnetic powder and the rotating stirring rod. S2. Vibration and blowing: After the pretreatment of coal powder is completed, the solenoid valve is opened, and the magnetic powder and coal powder fall onto the first screen plate. The vibration motor is started to make the outer shell vibrate, and the hot air blower and fan are started to blow air into the outer shell. At the same time, the second motor is started to make the drum rotate. S3. Initial screening: The first motor is controlled to make the first brush head move back and forth. The vibration of the outer shell can screen the coal powder, so that the coal powder with excessively large particles remains on the first screen plate, and the magnetic powder and the remaining coal powder fall onto the second screen plate. The first brush head, in conjunction with the vibration of the outer shell, accelerates the screening of the coal powder. S4. Secondary screening: The reciprocating movement of the first brush head drives the reciprocating movement of the second brush head, so that the magnetic powder and the remaining coal powder on the second screen plate are evenly distributed. Under the vibration of the outer shell, the coal powder with too small particles and some dust in the coal powder fall onto the mounting plate, and the remaining dust is raised and forms dust. S5. Dehydration and drying: The waste on the first screen plate and the mounting plate, as well as the material on the second screen plate, move towards the recycling box and the collection box under the vibration of the outer shell, and work with the drum, the first magnet and the second magnet, as well as hot air and cold air to complete the dehydration and drying of the coal powder. S6. Monitoring and control: During the above movement process, if the thermal imaging probe detects that the coal powder has agglomerated, the energized electromagnet will attract magnetic powder to disperse the agglomerated coal powder. If the thermal imaging probe detects that the coal powder is unevenly distributed, the drum speed and direction will be adjusted to disperse the coal powder from the thicker area to the thinner area. S7. Collection and recycling: After drying and deashing, the coal powder falls into the collection box, the magnetic powder is adsorbed by the magnetic roller, and the waste on the first screen plate and the mounting plate falls into two recycling boxes respectively. The dust is discharged through the exhaust pipe and enters the bag filter after passing through the cyclone separation system.

[0006] A high-precision dry deashing and upgrading method for low-quality coal, applied to the above-described process, uses the following apparatus: a shell and a screw feeder; two vibrating motors are symmetrically mounted on the shell, and two shock-absorbing bases are symmetrically mounted on the bottom of the shell; and the method further includes: A pretreatment mechanism, which is installed on the outer shell and the screw feeder, is used to add heated magnetic powder into the coal powder in the screw feeder and perform preliminary crushing, separation and drying. A screening and drying mechanism is installed inside the outer shell and is used to perform secondary crushing, separation and drying of coal powder entering the outer shell; The waste recycling mechanism and the collection mechanism are both installed on the outer shell. The waste recycling mechanism is used to recycle impurities and dust in the coal powder inside the outer shell, and the collection mechanism is used to collect the coal powder after drying and deashing.

[0007] Compared with existing technologies, the advantages of this invention are: 1. This invention, through the coordinated operation of a pretreatment mechanism, a screening and drying mechanism, a waste recycling mechanism, and a collection mechanism, not only utilizes the mixing of heated magnetic powder with the coal powder to be treated and the rotation of the stirring rod to preheat and initially crush and separate the coal powder, thus preparing it for the subsequent dehydration and drying process, but also utilizes the vibration of the outer shell, the air force blown by the hot air blower and the fan, the screening of the first and second screen plates, the magnetic setting of the drum, and the impact of the magnetic powder to promote secondary crushing and separation of the coal powder during the subsequent flow drying process, and to separate, discharge, and recycle unqualified coal powder and dust, thereby effectively improving the overall quality of coal powder drying and deashing.

[0008] 2. This invention, through the setting of auxiliary components, utilizes the counterclockwise rotation of the drum and the ball bearings in its air holes to drive the coal powder to rotate counterclockwise in the air. This rotation not only increases the residence time of the coal powder in the air but also allows the coal powder to come into more thorough contact with the hot air, thereby improving the efficiency of dehydration and drying of the coal powder. Furthermore, the clockwise rotation of the spiral fan blades inside the drum causes the hot air entering the hot air drum to form turbulence at the spiral fan blades and act on the coal powder through the air holes, thereby ensuring that the hot air can come into more uniform contact with the coal powder. When the hot air passes through the air holes on the drum, it will encounter the obstruction and disturbance of the ball bearings. This obstruction and disturbance will enhance the turbulence effect of the hot air, allowing the hot air to mix more thoroughly with the coal powder, thereby improving the quality of dehydration and drying of the coal powder.

[0009] 3. By setting up the screening control component, the present invention utilizes the reciprocating movement of the first and second brush heads to cooperate with the vibration of the outer shell to accelerate the screening of coal powder by the first screen plate, while also controlling the thickness of the coal powder and magnetic powder falling on the second screen plate and making it more uniform. This ensures that the coal powder can be uniformly subjected to heat, thereby effectively improving the efficiency and quality of coal powder dehydration and drying.

[0010] 4. By incorporating an anti-overflow component, this invention utilizes the attraction of the first magnet and the repulsion of the second magnet to cause the magnetic powder to circulate and move up and down during the flow drying process. This allows the magnetic powder to compress and disperse clumps of coal powder, improving the flow state of the coal powder and further enhancing the quality of coal powder dehydration and drying. Furthermore, it prevents the magnetic powder from overflowing from the processing area due to vibrations of the outer shell, wind blowing, and the magnetic action of the drum and the first magnet, thus effectively ensuring the quality of coal powder dehydration and drying.

[0011] 5. By incorporating an efficiency-enhancing component, this invention enables the use of a thermal imaging probe to detect coal powder agglomeration. By energizing an electromagnet at the corresponding location, magnetic powder is attracted to the agglomerated coal powder, thereby dispersing the agglomerated coal powder and increasing the heat transfer efficiency to that location. When the thermal imaging probe detects uneven coal powder distribution, the second motor is controlled to adjust the rotation speed and direction of the drum at the corresponding location, dispersing the coal powder from the thicker areas to the thinner areas. This effectively ensures the efficiency and quality of coal powder dehydration and drying. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of a high-precision dry deashing and upgrading method for low-quality coal proposed in this invention. Figure 2 This is a top view of a high-precision dry deashing and upgrading method for low-quality coal proposed in this invention. Figure 3 This is a side view of a high-precision dry deashing and upgrading method for low-quality coal proposed in this invention. Figure 4 This is a full sectional side view of a high-precision dry deashing and upgrading method for low-quality coal proposed in this invention. Figure 5 This is a schematic diagram of the full cross-sectional structure of the mixing chamber in the high-precision dry deashing and upgrading method for low-quality coal proposed in this invention. Figure 6 This is a full cross-sectional front view of a high-precision dry deashing and upgrading method for low-quality coal proposed in this invention. Figure 7 This is a bottom view of the first screen plate in the high-precision dry deashing and upgrading method for low-quality coal proposed in this invention. Figure 8 This is a schematic diagram of the full cross-sectional structure of the second screen plate in the high-precision dry deashing and upgrading method for low-quality coal proposed in this invention. Figure 9 This is a schematic diagram of the full cross-sectional structure of the drum in the high-precision dry deashing and upgrading method for low-quality coal proposed in this invention. Figure 10 for Figure 9 A magnified view of the details at point A; Figure 11 for Figure 9 A magnified view of the details at point B.

[0013] In the diagram: 1. Outer shell; 2. Feed inlet; 3. Screw feeder; 4. Hot air blower; 5. Air outlet duct; 6. Cyclone separation system; 7. Bag filter; 8. Mixing chamber; 9. First motor; 10. Second motor; 11. Vibrating motor; 12. Shock-absorbing base; 13. First discharge pipe; 14. Second discharge pipe; 15. Third discharge pipe; 16. Magnetic roller; 17. Fan; 18. Recycling box; 19. Lead screw; 20. Connecting plate; 21. Solid... 21. Fixed rod; 22. First brush head; 23. Second brush head; 24. First sieve plate; 25. Thermal imaging probe; 26. First magnet; 27. Second magnet; 28. Second sieve plate; 29. ​​Electromagnet; 30. Mounting plate; 31. Feed pipe; 32. Third motor; 33. Stirring rod; 34. Feed pipe; 35. Drum; 36. Rotating rod; 37. Spiral fan blade; 38. Internal gear ring; 39. First gear; 40. Second gear; 41. Ball bearing. Detailed Implementation

[0014] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0015] Reference Figures 1 to 11 A high-precision dry deashing and upgrading process for low-quality coal includes the following process steps: S1. Conveying and pre-treatment: The heated magnetic powder and the lignite powder to be treated are conveyed to the mixing chamber 8. During the conveying process, the heated magnetic powder is used to preheat and initially separate the coal powder. After entering the mixing chamber 8, the coal powder is crushed by the rotating stirring rod 33. S2. Vibration and blowing: After the pretreatment of coal powder is completed, the solenoid valve is opened, and the magnetic powder and coal powder fall onto the first screen plate 24. The vibration motor 11 is started to make the outer shell 1 vibrate, and the hot air blower 4 and the fan 17 are started to blow air from bottom to top toward the second screen plate 28. At the same time, the second motor 10 is started to make the drum 35 rotate counterclockwise. S3. Initial screening: The first motor 9 is controlled to make the first brush head 22 move back and forth. The vibration of the outer shell 1 can screen the coal powder, so that the coal powder with excessively large particles remains on the first screen plate 24, and the magnetic powder and the remaining coal powder fall onto the second screen plate 28. The reciprocating movement of the first brush head 22, together with the vibration of the outer shell 1, can accelerate the screening of coal powder. S4. Secondary screening: The first brush head 22 moves back and forth, driving the second brush head 23 to move back and forth. The magnetic powder and the remaining coal powder on the second screen plate 28 are evenly distributed under the action of the second brush head 23. Under the vibration of the outer shell 1, the coal powder with too small particles and some dust in the coal powder fall onto the mounting plate 30, and the remaining dust is raised and forms dust. S5. Dehydration and drying: The waste on the first screen plate 24 and the mounting plate 30, as well as the magnetic powder and coal powder on the second screen plate 28, move towards the recycling box 18 and the collection box under the vibration of the outer shell 1. During the movement and vibration, the roller 35, the first magnet 26 and the second magnet 27, as well as hot air and cold air are used to complete the effective dehydration and drying of the coal powder. S6. Monitoring and control: During the movement of magnetic powder and coal powder on the second sieve plate 28, if the thermal imaging probe 25 detects that the coal powder has agglomerated, the energized electromagnet 29 will attract the magnetic powder to disperse the agglomerated coal powder. If the thermal imaging probe 25 detects that the coal powder is unevenly distributed in some areas, the rotation speed and direction of the drum 35 will be adjusted to disperse the coal powder from the thicker areas to the thinner areas. S7. Collection and recycling: The dried and de-ashed coal powder on the second screen plate 28 falls into the collection box. The magnetic powder is adsorbed by the rotating magnetic roller 16. The waste on the first screen plate 24 and the mounting plate 30 falls into the two recycling boxes 18 respectively. The dust in the outer shell 1 is discharged through the air outlet pipe 5 and enters the bag filter 7 after passing through the cyclone separation system 6.

[0016] Reference Figures 1 to 5 A high-precision dry deashing and upgrading method for low-quality coal is applied to the above-mentioned process. The method uses the following apparatus: a shell 1 and a screw feeder 3. The screw feeder 3 is used to convey the coal powder to be processed into the shell 1. Two vibrating motors 11 are symmetrically mounted on the shell 1, and two shock-absorbing bases 12 are symmetrically mounted on the bottom of the shell 1. A pretreatment mechanism is provided on the shell 1 and the screw feeder 3 for adding heated magnetic powder to the coal powder in the screw feeder 3 and performing preliminary crushing, separation, and drying. The screw feeder 3 is existing technology, and its specific structural design will not be described in detail here. The pretreatment mechanism includes a feed inlet 2 and a mixing chamber 8. The feed inlet 2... The mixing chamber 8 is installed on the screw feeder 3 and connected to the input end of the screw feeder 3. The bottom end of the mixing chamber 8 is equipped with a feed pipe 34, and the mixing chamber 8 is fixedly connected to the inside of the outer shell 1 through the feed pipe 34. A solenoid valve is installed inside the feed pipe 34. The solenoid valve is existing technology and is not shown in the figure. Its specific structural design will not be described here. A conveying pipe 31 is installed at the top of the mixing chamber 8, and the mixing chamber 8 is connected to the output end of the screw feeder 3 through the conveying pipe 31. The mixing chamber 8 is located at the top of the outer shell 1 near the edge, and a third motor 32 is installed at the top of the mixing chamber 8. The output end of the third motor 32 passes through the top wall of the mixing chamber 8 and is fixedly connected to the mixing rod 33.

[0017] Reference Figures 1 to 6The outer casing 1 is equipped with a screening and drying mechanism for secondary crushing, separation, and drying of the coal powder entering the outer casing 1. The screening and drying mechanism includes a first screen plate 24, a second screen plate 28, and a mounting plate 30. The first screen plate 24, the second screen plate 28, and the mounting plate 30 are installed sequentially from top to bottom inside the outer casing 1, and are all inclined away from the screw feeder 3. The inclination angle of the second screen plate 28 is smaller than that of the first screen plate 24 and the mounting plate 30, and the diameter of the screen holes on the first screen plate 24 is larger than that on the second screen plate 28. The diameter of the screen holes on 8 is specified. A blowing assembly is provided on the outer casing 1 for blowing hot and cold air into the outer casing 1. The blowing assembly includes a hot air blower 4 and a fan 17. Both the hot air blower 4 and the fan 17 are located on the ground, and the output ends of both the hot air blower 4 and the fan 17 penetrate through the side wall of the outer casing 1 and are set upwards. Both the hot air blower 4 and the fan 17 are located between the second screen plate 28 and the mounting plate 30. The fan 17 is located near the end of the outer casing 1 away from the screw feeder 3, and the hot air blower 4 is located between the screw feeder 3 and the fan 17.

[0018] Reference Figures 1 to 11 The second screen plate 28 is equipped with auxiliary components to improve the separation and drying effect of coal powder. The auxiliary components include two extension plates and multiple rollers 35. The two extension plates are respectively installed at the bottom end of the second screen plate 28 near the two side edges, with the outer wall of the extension plates contacting the inner wall of the outer casing 1. The multiple rollers 35 are evenly rotated and connected to the two extension plates. Multiple second motors 10 are evenly installed on the outer wall of the outer casing 1. The output ends of the multiple second motors 10 sequentially penetrate the outer wall of the outer casing 1 and one of the extension plates, and are respectively fixedly connected to the multiple rollers 35. The top of the second screen plate 28 has multiple through slots corresponding to the multiple rollers 35. The upper part of the cylinder 35 is located in the through groove. The cylinder 35 is made of magnetic material, and the magnetism of the cylinder 35 is the same as that of the magnetic powder. Multiple air holes are evenly distributed through the outer wall of the cylinder 35. Ball bearings 41 are rotatably connected in the air holes. Rotating rods 36 are rotatably connected to two opposite inner walls of the cylinder 35. Multiple spiral fan blades 37 are evenly installed on the rotating rods 36. A second gear 40 is installed near one edge of the outer wall of the rotating rod 36. An internal gear ring 38 is installed on the inner wall of the cylinder 35. A first gear 39 is rotatably connected to one inner wall of the rotating rod 36. The internal gear ring 38 and the second gear 40 both mesh with the first gear 39.

[0019] Reference Figures 1 to 4The outer casing 1 is equipped with a screening control component to accelerate the screening speed of coal powder and magnetic powder on the first screen plate 24 and to control the thickness of coal powder and magnetic powder on the second screen plate 28. The screening control component includes a mounting frame, which is fixedly installed on one end of the outer casing 1 near the screw feeder 3. A fixing rod 21 is fixedly installed inside the mounting frame. A first motor 9 is installed on the outer wall of the mounting frame. A connecting plate 20 is slidably connected to the fixing rod 21. The output end of the first motor 9 passes through the outer wall of the mounting frame and is fixedly connected to a lead screw 19. The end of the lead screw 19 away from the first motor 9 is connected to the inner wall of the mounting frame. The wall is rotatably connected, and the lead screw 19 is threadedly connected to the connecting plate 20. Two sliding rods are installed on the side of the connecting plate 20 facing the outer shell 1. Two sliding grooves are respectively provided through one end of the outer shell 1 for the two sliding rods to slide. The ends of the two sliding rods away from the connecting plate 20 pass through the two sliding grooves respectively and are respectively fixedly connected to the first brush head 22 and the second brush head 23. The bristles on the first brush head 22 are in contact with the top of the first sieve plate 24. The second brush head 23 is located between the first sieve plate 24 and the second sieve plate 28, and there is a gap between the bristles on the second brush head 23 and the second sieve plate 28.

[0020] Reference Figures 4 to 7 An anti-overflow component is provided at the bottom of the first sieve plate 24 to prevent magnetic powder on the second sieve plate 28 from overflowing into the area between the first sieve plate 24 and the second sieve plate 28. The anti-overflow component includes multiple first magnets 26 and multiple second magnets 27. The multiple first magnets 26 and multiple second magnets 27 are all installed at the bottom of the first sieve plate 24 and are arranged alternately. The magnetism of the first magnet 26 is opposite to that of the magnetic powder, and the magnetism of the second magnet 27 is the same as that of the magnetic powder. An efficiency enhancement component is provided inside the outer shell 1 to more effectively separate the clumps of coal powder on the second sieve plate 28. The efficiency enhancement component includes multiple thermal imaging probes 25 and multiple electromagnets 29. The multiple thermal imaging probes 25 are evenly installed at the bottom of the first sieve plate 24, and the positions of the multiple thermal imaging probes 25 are respectively located on the non-opposing side of each adjacent first magnet 26 and second magnet 27. The multiple electromagnets 29 are equally fixed and embedded in two opposing inner sidewalls inside the outer shell 1, and the bottom positions of the multiple electromagnets 29 correspond to the top positions of the second sieve plate 28.

[0021] Reference Figures 1 to 4The outer casing 1 is equipped with a waste recycling mechanism and a collection mechanism. The waste recycling mechanism is used to recover impurities and dust from the coal powder inside the outer casing 1, and the collection mechanism is used to collect the coal powder after drying and deashing. The waste recycling mechanism includes a cyclone separation system 6, a bag filter 7, and two collection boxes 18. The cyclone separation system 6, the bag filter 7, and the two collection boxes 18 are all located on the ground. The output end of the cyclone separation system 6 is connected to the input end of the bag filter 7, and an outlet duct 5 is installed at the input end of the cyclone separation system 6. The cyclone separation system 6 discharges air through the outlet duct 5. The air duct 5 is connected to the interior of the outer shell 1. The air outlet duct 5 is located at the top of the outer shell 1. The first discharge pipe 13 and the third discharge pipe 15 are fixedly connected to the end of the outer shell 1 away from the screw feeder 3. The connection points of the first discharge pipe 13 and the third discharge pipe 15 with the outer shell 1 correspond to the positions of the first screen plate 24 and the mounting plate 30, respectively. The openings at the bottom of the first discharge pipe 13 and the third discharge pipe 15 correspond to the positions of the two recycling boxes 18, respectively. The cyclone separation system 6 and the bag filter 7 are existing technologies, and their specific structural designs will not be described in detail here.

[0022] Reference Figure 1 , Figure 3 and Figure 4 The collection mechanism includes a second discharge pipe 14, a collection box, and two mounting platforms. The collection box and the two mounting platforms are all set on the ground. The second discharge pipe 14 is fixedly connected to the end of the outer shell 1 away from the screw feeder 3, and the position of the connection between the second discharge pipe 14 and the outer shell 1 corresponds to the position of the second screen plate 28. The position of the bottom opening of the second discharge pipe 14 corresponds to the position of the collection box. The two mounting platforms are located at both ends of the collection box, and a magnetic roller 16 is rotatably connected to both mounting platforms. One of the mounting platforms is equipped with a drive unit that drives the magnetic roller 16 to rotate. The drive unit is existing technology, and its specific structural design will not be described in detail here. The magnetic roller 16 is located between the second discharge pipe 14 and the collection box, and the magnetic roller 16 is located diagonally below the bottom opening of the second discharge pipe 14. The magnetism of the magnetic roller 16 is opposite to that of the magnetic powder.

[0023] This invention is applied to the drying and deashing of lignite powder with high moisture content. First, the lignite powder to be treated is added to the screw feeder 3, and heated magnetic powder is poured into the screw feeder 3 from the feed inlet 2. Together with the lignite powder, the magnetic powder is conveyed to the mixing chamber 8 through the screw feeder 3. During this conveying process, the heated magnetic powder can transfer heat to the lignite powder, preheating it and preparing it for the subsequent dehydration and drying process. At the same time, the magnetic powder can also impact the lignite powder during the conveying process, helping to break the adhesion and agglomeration between lignite powder particles and improve its flowability. Subsequently, the mixture of lignite powder and magnetic powder enters the mixing chamber 8 through the conveying pipe 31. At this time, the third motor 32 is started, causing the stirring rod 33 to start rotating, which initially crushes the mixture of lignite powder and magnetic powder. Under the combined action of the impact of the magnetic powder on the lignite powder and the crushing action of the stirring rod 33, the lignite powder is pre-separated, thereby improving the efficiency and quality of subsequent drying.

[0024] After preheating and pre-separation of the lignite powder, the solenoid valve is opened, and the magnetic powder and lignite powder fall onto the first screen plate 24 through the feed pipe 34. At this time, the vibration motor 11 is started to vibrate the outer casing 1, and the hot air blower 4 and the fan 17 are started to blow hot and cold air into the outer casing 1. The hot and cold air are blown out from bottom to top towards the second screen plate 28. The vibration of the outer casing 1 can separate the lignite powder that has not been completely separated or has re-agglomerated on the first screen plate 24, and it is then screened by the first screen plate 24. The diameter of the sieve holes on the first sieve plate 24 is larger than that on the second sieve plate 28, so that the large-sized lignite powder remains on the first sieve plate 24, while the magnetic powder and the remaining lignite powder fall onto the second sieve plate 28. Under the vibration of the outer shell 1, the small-sized lignite powder and some of the very fine dust in the lignite powder on the second sieve plate 28 fall onto the mounting plate 30. The remaining dust will be raised and form dust. This dust will be carried by the airflow blown out by the hot air blower 4 and the fan 17, and then discharged through the air outlet duct 5.

[0025] Since the first screen plate 24, the second screen plate 28, and the mounting plate 30 are all inclined towards the recycling box 18 and the collection box (i.e., inclined towards the end of the device), the waste on the first screen plate 24 and the mounting plate 30, as well as the material on the second screen plate 28, will begin to flow under the vibration of the outer shell 1. The material on the second screen plate 28 will be subjected to hot and cold air during the flow. Since the first screen plate 24 and the mounting plate 30 have a larger inclination angle than the second screen plate 28, the waste on the first screen plate 24 and the mounting plate 30 will flow to the end of the device faster than the material on the second screen plate 28. This ensures that the hot and cold air blown from bottom to top will not be blocked by the waste on the first screen plate 24, thus ensuring air circulation inside the outer shell 1 and allowing the dust inside the outer shell 1 to be smoothly discharged by the air outlet duct 5 along the airflow.

[0026] Simultaneously, multiple second motors 10 are activated, causing multiple rollers 35 to rotate counterclockwise. While the rollers 35 rotate, the first motor 9 is controlled to rotate the lead screw 19, thereby moving the first brush head 22 and the second brush head 23. Subsequently, the first motor 9 is controlled to reverse, causing the first brush head 22 and the second brush head 23 to reciprocate. Since the bristles on the first brush head 22 are in contact with the top of the first screen plate 24, the reciprocating movement of the first brush head 22, combined with the vibration of the outer casing 1, accelerates the screening of the separated lignite powder by the first screen plate 24, allowing the magnetic powder and lignite powder to fall more quickly onto the second screen plate 2. 8. Since the blower 17 is located near the end of the outer casing 1 away from the screw feeder 3, and the hot air blower 4 is located between the screw feeder 3 and the blower 17, when the hot air and cold air blow to the second screen plate 28, the hot air will first dry the lignite powder, while the cold air will cool the dried lignite powder. When the hot air enters from the bottom and passes through the lignite powder, its blowing force on the lignite powder will, together with the vibration of the outer casing 1, cause the lignite powder to continuously tumble and jump on the second screen plate 28, eventually forming a fluidized state similar to a liquid, ensuring that the lignite powder can be uniformly heated and avoiding the problems of local overheating or uneven drying.

[0027] Meanwhile, since there is a gap between the bristles on the second brush head 23 and the second screen plate 28, the reciprocating movement of the second brush head 23 can spread the lignite powder and magnetic powder falling on the second screen plate 28 evenly. This controls the thickness of the lignite powder and magnetic powder falling on the second screen plate 28 and makes it more uniform. As a result, when the second screen plate 28 vibrates, the lignite powder and magnetic powder can flow more evenly, further ensuring that the lignite powder is evenly heated, effectively improving the quality of dehydration and drying of the lignite powder. In addition, since the magnetic powder can fill the gaps between the lignite powder and has a high thermal conductivity, it can increase the effective contact area between the lignite powder and the hot air. This increase in contact area, combined with the excellent thermal conductivity of the magnetic powder itself, can significantly improve the heat transfer efficiency, ensuring that the lignite powder is heated more evenly and efficiently, thereby improving the efficiency and quality of dehydration and drying of the lignite powder.

[0028] When the lignite powder and magnetic powder flow to the position of the roller 35 on the second screen plate 28, the rotating roller 35 will drive the lignite powder to rotate counterclockwise in the air through the friction of its surface (at this time, the magnetic powder is also moving synchronously). This rotation not only increases the residence time of the lignite powder in the air, but also makes the movement path of the lignite powder more complex, thereby obtaining a longer drying time for the same distance, effectively improving the dehydration and drying efficiency of the lignite powder. Since the roller 35 is made of magnetic material and its magnetism is the same as that of the magnetic powder, the rotating roller 35 will exert a repulsive force on the magnetic powder, making the movement of the magnetic powder more intense. The intense movement of the magnetic powder can continuously collide with the lignite powder it contacts. At the same time, since the magnetic powder usually has a small particle size and high hardness, it makes them more effective in impacting the lignite powder. The coal powder generates sufficient impact force to break up the agglomerated lignite powder without excessively abrading it. This effectively disperses the agglomerated lignite powder into smaller particles, which is more conducive to the dehydration and drying of the lignite powder and the separation of dust. When the drum 35 rotates, the rotating rod 36 inside it will rotate clockwise under the combined action of the internal gear ring 38, the first gear 39 and the second gear 40. This causes the spiral fan blade 37 to rotate clockwise. The opposite rotation direction of the drum 35 and the spiral fan blade 37 allows the hot air entering the hot air drum 35 to form turbulence at the spiral fan blade 37. Finally, the hot air acts on the lignite powder through the air holes on the surface of the drum 35, ensuring that the hot air can contact the lignite powder more evenly, thereby improving the heating uniformity of the lignite powder.

[0029] Furthermore, when the drum 35 rotates, the ball bearings 41 inside its air holes also roll, which can more effectively push the lignite powder and make it rotate, thus allowing it to come into more full contact with the hot air. When the hot air passes through the air holes of the drum 35, it will encounter the obstruction and disturbance of the ball bearings 41. This obstruction and disturbance will enhance the turbulence effect of the hot air, allowing the hot air to mix more fully with the lignite powder, thereby further improving the quality of dehydration and drying of the lignite powder.

[0030] Because the magnetism of the first magnet 26 is opposite to that of the magnetic powder, while the magnetism of the second magnet 27 is the same as that of the magnetic powder, when the lignite powder and magnetic powder are lifted by the drum 35, the first magnet 26 attracts the magnetic powder, thus intensifying its upward movement. As the lignite powder and magnetic powder continue to flow, they are repelled by the second magnet 27, causing the magnetic powder to move downwards. This helps prevent the magnetic powder from moving excessively upwards under the attraction of the first magnet 26 and the repulsion of the drum 35, thereby avoiding the magnetic powder overflowing from the processing area (i.e., the area between the first screen plate 24 and the second screen plate 28). Simultaneously, the downward or upward moving magnetic powder compresses and disperses the agglomerated lignite powder, thus improving the coal processing efficiency. The flow state of the powder further improves the quality of dehydration and drying of lignite powder. Although the magnetic powder overflowing from the treatment area can pass through the first screen plate 24 and fall smoothly back onto the second screen plate 28, since both the magnetic powder and the lignite powder are in a flowing state, the impact force on the lignite powder from the magnetic powder will be reduced during the falling process. Moreover, the magnetic powder is unevenly distributed after falling, which is not conducive to the high-precision separation of lignite powder, thus reducing the quality of dehydration and drying of lignite powder. Since the weight of lignite powder itself is larger than that of magnetic powder, and it neither generates repulsion with the roller 35 nor is attracted by the first magnet 26, the lignite powder will not overflow.

[0031] During the movement (i.e., flow) of magnetic powder and coal powder on the second sieve plate 28, when the thermal imaging probe 25 detects that lignite coal powder on the second sieve plate 28 has agglomerated, two opposing electromagnets 29 at corresponding positions can be energized, making the two electromagnets 29 have opposite magnetic properties. This causes one electromagnet 29 to attract magnetic powder and the other electromagnet 29 to repel magnetic powder. At this time, it is necessary to ensure that the position of the electromagnet 29 that attracts magnetic powder is close to the agglomerated location of lignite coal powder. Then, under the action of electromagnetic force, the magnetic powder will move towards the area where lignite coal powder is agglomerated and accumulate there, thereby dispersing the agglomerated lignite coal powder and increasing the heat transfer efficiency of the lignite coal powder at that location. When the thermal imaging probe 25 detects that the distribution of lignite coal powder on the second sieve plate 28 is not very uniform, the rotation speed of the corresponding roller 35 and the direction of rotation of the corresponding roller 35 can be increased by controlling the second motor 10 to disperse the coal powder from the thicker accumulation area to the thinner area, thereby effectively ensuring the efficiency and quality of dehydration and drying of lignite coal powder.

[0032] The magnetic powder and the dried and deashed lignite powder are finally discharged from the second discharge pipe 14. At this time, the drive unit is activated to rotate the magnetic roller 16. The magnetic powder discharged from the second discharge pipe 14 will pass through the rotating magnetic roller 16 and be attracted by it. As the magnetic roller 16 rotates, the attracted magnetic powder will be carried to the other end of the magnetic roller 16 and unloaded or collected there. The dried and deashed lignite powder discharged from the second discharge pipe 14 will fall into the collection box after passing through the magnetic roller 16, thus completing the collection of the upgraded lignite powder. The waste on the first screen plate 24 and the mounting plate 30... Before completing the above collection process, the dust will fall into two recycling bins 18 respectively. In addition, the dust discharged by the exhaust duct 5 will enter the cyclone separation system 6. In the above system, the larger dust particles in the dust are effectively separated under the action of centrifugal force. The exhaust gas after being treated by the cyclone separation system 6 will then enter the bag filter 7 for further treatment. At this time, the tiny dust particles in the exhaust gas are intercepted, and the purified gas will be discharged. Afterwards, the dust particles captured in the cyclone separation system 6 and the bag filter 7 will be cleaned regularly and centrally treated or recycled.

[0033] 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 principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-precision dry deashing and upgrading method for low-quality coal, using the following device, including a shell (1) and a screw feeder (3), wherein two vibrating motors (11) are symmetrically mounted on the shell (1), and two shock-absorbing bases (12) are symmetrically mounted on the bottom end of the shell (1), characterized in that, Also includes: The pretreatment mechanism is set on the outer shell (1) and the screw feeder (3) for adding heated magnetic powder into the coal powder in the screw feeder (3) and performing preliminary crushing, separation and drying; The screening and drying mechanism is located inside the outer shell (1) and is used to perform secondary crushing, separation and drying of coal powder entering the outer shell (1). Waste recycling mechanism and collection mechanism are both installed on the outer shell (1). The waste recycling mechanism is used to recycle impurities and dust in the coal powder inside the outer shell (1). The collection mechanism is used to collect the coal powder after drying and deashing. The screening and drying mechanism includes a first screen plate (24), a second screen plate (28), and a mounting plate (30). The first screen plate (24), the second screen plate (28), and the mounting plate (30) are installed in the outer shell (1) from top to bottom, and are all inclined away from the screw feeder (3). The inclination angle of the second screen plate (28) is smaller than that of the first screen plate (24) and the mounting plate (30). The diameter of the screen holes on the first screen plate (24) is larger than that on the second screen plate (28). The outer shell (1) is provided with a blowing assembly for blowing hot and cold air into the outer shell (1). The second screen plate (28) is provided with an auxiliary assembly for improving the separation and drying effect of coal powder. The auxiliary components include two extension plates and multiple rollers (35). The two extension plates are respectively installed at the bottom of the second screen plate (28) near the two side edges. The outer wall of the extension plate is in contact with the inner wall of the outer shell (1). The multiple rollers (35) are uniformly rotated and connected to the two extension plates. Multiple second motors (10) are uniformly installed on the outer wall of the outer shell (1). The output ends of the multiple second motors (10) pass through the outer wall of the outer shell (1) and one of the extension plates in sequence, and are fixedly connected to the multiple rollers (35) respectively. The top of the second screen plate (28) is provided with multiple through slots corresponding to the multiple rollers (35). The part above the rollers (35) is in the through slots. The rollers (35) are made of magnetic material, and the magnetism of the rollers (35) is the same as that of the magnetic powder. Multiple air holes are uniformly provided on the outer wall of the rollers (35). A ball bearing (41) is rotatably connected inside the air hole. A rotating rod (36) is rotatably connected to two opposite inner walls inside the roller (35). Multiple spiral fan blades (37) are evenly installed on the rotating rod (36). A second gear (40) is installed on the outer wall of the rotating rod (36) near one end edge. An internal gear ring (38) is installed on the inner wall of the roller (35). A first gear (39) is rotatably connected to one of the inner walls of the rotating rod (36). The internal gear ring (38) and the second gear (40) both mesh with the first gear (39). It also includes an anti-overflow component and an efficiency enhancement component. The anti-overflow component includes multiple first magnets (26) and multiple second magnets (27). The multiple first magnets (26) and multiple second magnets (27) are all installed at the bottom of the first sieve plate (24) and are arranged alternately. The magnetism of the first magnet (26) is opposite to that of the magnetic powder, and the magnetism of the second magnet (27) is the same as that of the magnetic powder. The efficiency enhancement component includes multiple thermal imaging probes (25) and multiple electromagnets (29). The multiple thermal imaging probes (25) are evenly installed at the bottom of the first sieve plate (24), and the positions of the multiple thermal imaging probes (25) are respectively located on the non-opposing side of each adjacent first magnet (26) and second magnet (27). The multiple electromagnets (29) are equally fixed and embedded in two opposing inner sidewalls inside the outer shell (1), and the bottom position of the multiple electromagnets (29) corresponds to the top position of the second sieve plate (28). The quality improvement method includes the following process steps: S1. Conveying and pretreatment: The heated magnetic powder and the lignite powder to be treated are conveyed to the mixing chamber (8), and the coal powder is preheated and initially crushed and separated by the heated magnetic powder and the rotating stirring rod (33). S2. Vibration and blowing: After the pretreatment of coal powder is completed, the solenoid valve is opened, and the magnetic powder and coal powder fall onto the first screen plate (24). The vibration motor (11) is started to make the outer shell (1) vibrate, and the hot air blower (4) and the fan (17) are started to blow air into the outer shell (1). At the same time, the second motor (10) is started to make the drum (35) rotate. S3. Initial screening: Control the first motor (9) to make the first brush head (22) move back and forth. The vibration of the outer shell (1) can screen the coal powder, so that the coal powder with excessively large particles remains on the first screen plate (24), and the magnetic powder and the remaining coal powder fall onto the second screen plate (28). The first brush head (22) cooperates with the vibration of the outer shell (1) to accelerate the screening of coal powder. S4. Secondary screening: The first brush head (22) moves back and forth, driving the second brush head (23) to move back and forth, so that the magnetic powder and the remaining coal powder on the second screen plate (28) are evenly distributed, and under the vibration of the outer shell (1), the coal powder with too small particles and some dust in the coal powder fall onto the mounting plate (30), and the remaining dust is raised and forms dust. S5. Dehydration and drying: The waste on the first screen plate (24) and the mounting plate (30) and the material on the second screen plate (28) move towards the recycling box (18) and the collection box under the vibration of the outer shell (1), and work with the roller (35), the first magnet (26) and the second magnet (27) as well as hot air and cold air to complete the dehydration and drying of the coal powder. S6. Monitoring and control: During the above movement process, if the thermal imaging probe (25) detects that the coal powder has agglomerated, the electromagnet (29) with power is used to attract magnetic powder to disperse the agglomerated coal powder. If the thermal imaging probe (25) detects that the coal powder is unevenly distributed, the rotation speed and direction of the drum (35) are adjusted to disperse the coal powder from the thicker area to the thinner area. S7. Collection and recycling: After drying and deashing, the coal powder falls into the collection box. The magnetic powder is adsorbed by the magnetic roller (16). The waste on the first screen plate (24) and the mounting plate (30) falls into the two recycling boxes (18) respectively. The dust is discharged through the air outlet pipe (5) and enters the bag filter (7) after passing through the cyclone separation system (6).

2. The method for high-precision dry deashing and upgrading of low-quality coal according to claim 1, characterized in that, The pretreatment mechanism includes a feed inlet (2) and a mixing chamber (8). The feed inlet (2) is installed on the screw feeder (3) and connected to the input end of the screw feeder (3). The bottom end of the mixing chamber (8) is equipped with a feed pipe (34), and the mixing chamber (8) is fixedly connected to the inside of the outer shell (1) through the feed pipe (34). A solenoid valve is installed inside the feed pipe (34). A conveying pipe (31) is installed at the top of the mixing chamber (8), and the mixing chamber (8) is connected to the output end of the screw feeder (3) through the conveying pipe (31). The mixing chamber (8) is located at the top of the outer shell (1) near the edge, and a third motor (32) is installed at the top of the mixing chamber (8). The output end of the third motor (32) passes through the top wall of the mixing chamber (8) and is fixedly connected to a stirring rod (33).

3. The method for high-precision dry deashing and upgrading of low-quality coal according to claim 1, characterized in that, The blowing assembly includes a hot air blower (4) and a fan (17). Both the hot air blower (4) and the fan (17) are set on the ground, and the output ends of the hot air blower (4) and the fan (17) pass through the side wall of the outer shell (1) and are set upward. Both the hot air blower (4) and the fan (17) are located between the second screen plate (28) and the mounting plate (30). The fan (17) is located near the end of the outer shell (1) away from the screw feeder (3). The hot air blower (4) is located between the screw feeder (3) and the fan (17).

4. The method for high-precision dry deashing and upgrading of low-quality coal according to claim 1, characterized in that, It also includes a screening control component, which includes a mounting frame. The mounting frame is fixedly installed on one end of the outer shell (1) near the screw feeder (3), and a fixing rod (21) is fixedly installed inside the mounting frame. A first motor (9) is installed on the outer wall of the mounting frame. A connecting plate (20) is slidably connected to the fixing rod (21). The output end of the first motor (9) passes through the outer wall of the mounting frame and is fixedly connected to a lead screw (19). The end of the lead screw (19) away from the first motor (9) is rotatably connected to the inner wall of the mounting frame, and the lead screw (19) is threadedly connected to the connecting plate (20). Two sliding rods are installed on the side of the connecting plate (20) facing the outer shell (1). Two sliding grooves are provided through one end of the outer shell (1) for the two sliding rods to slide. The ends of the two sliding rods away from the connecting plate (20) pass through the two sliding grooves respectively and are fixedly connected to the first brush head (22) and the second brush head (23). The bristles on the first brush head (22) are in contact with the top of the first sieve plate (24). The second brush head (23) is located between the first sieve plate (24) and the second sieve plate (28), and there is a gap between the bristles on the second brush head (23) and the second sieve plate (28).

5. The method for high-precision dry deashing and upgrading of low-quality coal according to claim 1, characterized in that, The waste recycling mechanism includes a cyclone separator (6), a bag filter (7), and two recycling bins (18). The cyclone separator (6), bag filter (7), and two recycling bins (18) are all located on the ground. The output end of the cyclone separator (6) is connected to the input end of the bag filter (7), and an exhaust duct (5) is installed at the input end of the cyclone separator (6). The cyclone separator (6) is connected to the interior of the outer casing (1) through the exhaust duct (5). The air outlet pipe (5) is located at the top of the outer shell (1). The outer shell (1) is fixedly connected to the first discharge pipe (13) and the third discharge pipe (15) at the end away from the screw feeder (3). The connection points of the first discharge pipe (13) and the third discharge pipe (15) with the outer shell (1) correspond to the positions of the first screen plate (24) and the mounting plate (30), respectively. The openings at the bottom of the first discharge pipe (13) and the third discharge pipe (15) correspond to the positions of the two recycling boxes (18), respectively.

6. The method for high-precision dry deashing and upgrading of low-quality coal according to claim 1, characterized in that, The collection mechanism includes a second discharge pipe (14), a collection box, and two mounting platforms. The collection box and the two mounting platforms are all set on the ground. The second discharge pipe (14) is fixedly connected to the end of the outer shell (1) away from the screw feeder (3). The connection between the second discharge pipe (14) and the outer shell (1) corresponds to the position of the second screen plate (28). The position of the bottom opening of the second discharge pipe (14) corresponds to the position of the collection box. The two mounting platforms are located at both ends of the collection box. A magnetic roller (16) is rotatably connected to both mounting platforms. A drive unit for driving the magnetic roller (16) to rotate is installed on one of the mounting platforms. The magnetic roller (16) is located between the second discharge pipe (14) and the collection box. The magnetic roller (16) is located obliquely below the bottom opening of the second discharge pipe (14). The magnetism of the magnetic roller (16) is opposite to that of the magnetic powder.

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