Control method for raw coal impurity removal

Abstract

The invention relates to the technical field of raw coal impurity removal, and provides a control method for raw coal impurity removal. The control method comprises the following steps that firstly, raw coal is subjected to preliminary screening, fine coal powder is filtered out, meanwhile, coal flow is evenly distributed, and the raw coal with the fine coal powder filtered out enters a next-stage working procedure; secondly, in the metal impurity removal process, in the raw coal transportation process, metal impurities existing in the raw coal are detected and removed in combination with a material recognizer, and the raw coal with the metal impurities removed is conveyed to the next stage of impurity removal and screening process; then, screening of the coal flow is achieved in the impurity removal and screening procedure, the coal flow meeting the blanking requirement falls and is divided under the action of gravity and kinetic energy, and large coal briquettes and impurities which cannot fall off are further screened and subjected to impurity removal; and finally, coal briquettes carried in the impurities are screened out, and the impurities are conveyed to a recycling box. According to the control method, iron metal impurities such as anchor rods in the raw coal can be removed, large impurities can also be removed, and the quality of the raw coal is effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of raw coal impurity removal, and in particular to a control method for raw coal impurity removal. Background Art

[0002] In the process of coal mining, due to the complex working conditions, light debris such as wood, rubber, woven bags, iron debris such as anchor rods and metal mesh, and large debris such as stones are often mixed in the underground mining process. If these debris enter the production system of the coal preparation plant and are not removed in time, it will not only cause system blockage and damage related structural equipment, but also cause production stagnation, affecting the overall production process of the coal mine.

[0003] However, the debris removal methods currently used in coal preparation plants are not intelligent enough to completely remove all types of debris. At the same time, if the debris is picked out manually, there are still problems such as low debris removal efficiency, high labor intensity for employees, and low safety factor. In addition, the debris is often not thoroughly cleaned, which seriously affects the intelligentization process of the coal preparation plant.

[0004] To this end, the present invention proposes a control method for removing impurities from raw coal. Summary of the invention

[0005] The object of the present invention is to provide a control method for removing impurities from raw coal, which can remove impurities in the raw coal to avoid system blockage and damage to equipment, thereby ensuring normal production operations in a coal mine.

[0006] In order to achieve the above object, the technical solutions adopted by the present invention are as follows:

[0007] A control method for removing impurities from raw coal comprises the following steps:

[0008] Step 1: First, the raw coal is preliminarily screened to remove fine coal powder and evenly distribute the coal flow. The raw coal after the fine coal powder is removed enters the next stage of metal debris removal process;

[0009] Step 2: In the metal impurity removal process, when the raw coal is being transported, the material identifier is used to detect and remove the metal impurities in the raw coal. The raw coal after the metal impurities are removed is transported to the next level of impurity removal and screening process.

[0010] Step 3: In the impurity removal and screening process, the coal flow is screened. The coal flow that meets the falling requirements falls under the action of gravity and kinetic energy, and the large coal blocks and debris that cannot fall are further screened and impurities removed;

[0011] Step 4: further screen out the carried coal lumps from the debris obtained in step 3, and transport the large coal lumps and debris to a recovery box.

[0012] Preferably, in step 1, the raw coal is preliminarily screened using a feed preliminarily screening mechanism;

[0013] Among them, the feed initial screening mechanism includes a feed funnel and a material leveler. A guide plate is arranged inside the feed funnel, and a screening groove is provided on the guide plate. The coal powder with a smaller particle size falls through the screening groove of the guide plate, and the lump raw coal enters the next level of transportation process through the discharge port of the feed funnel;

[0014] At the same time, a refining device is arranged at the rear side of the feed port and the discharge port of the feed hopper. The raw coal collides with the refining device, so that the raw coal can be evenly dispersed, reducing the viscosity of the coal flow.

[0015] Preferably, in step 2, the lump raw coal is transported by a coal conveyor belt transmission mechanism, and when the material identifier detects that metal impurities are mixed in the raw coal, the belt type iron removal mechanism is started to remove the metal impurities mixed in the raw coal;

[0016] The material identifier includes a metal detector, a coal flow sensor and a speed detection sensor;

[0017] Among them, the metal detector determines the presence and size of metal on the surface of the coal conveyor belt transmission mechanism through the induction data of electromagnetic pulse waves, and the detection data of the coal flow sensor and speed detection sensor assist in determining the instantaneous coal flow and detecting the instantaneous material position;

[0018] When the metal detector detects the presence of metal debris on the surface of the coal conveyor belt transmission mechanism, the coal flow sensor and the speed detection sensor are used to detect the position of the metal debris, and the belt type debris removal mechanism is started to remove the debris.

[0019] Preferably, in step 2, a belt-type iron removal mechanism is provided above the coal conveyor belt transmission mechanism; the belt-type iron removal mechanism comprises a debris transport belt, a belt motor and an electromagnet, wherein the electromagnet is provided in the interlayer space of the debris transport belt;

[0020] According to the detection results of the three sets of sensors of the material identifier, the electromagnetic excitation current is accurately turned on, and the electromagnet is used to excite magnetism to adsorb metal debris onto the debris transfer belt; at the moment of iron-coal separation, the belt motor of the belt-type iron removal mechanism is turned on, and its rotating debris transfer belt will inertia throw the metal objects adsorbed on the belt surface away from the belt, thereby realizing iron removal control.

[0021] Preferably, in step 3, large debris in the raw coal is screened out by setting a grate screening mechanism, wherein the grate screening mechanism includes an oil cylinder, a square tube and a swing rod, wherein the oil cylinder drives the square tube to rotate, and a plurality of swing rods arranged on the square tube rotate with the square tube, which can prevent large debris from being stuck in the gap between the swing rods, and the coal blocks fall into the silo below through the gap between the swing rods for storage, and the large debris is trapped on the swing rod waiting for the spinning and throwing operation;

[0022] The rotary roller hook type screening mechanism is provided to complete the rotary throwing and impurity removal operation of large debris, wherein the rotary roller hook type screening mechanism includes a reduction motor, a cam divider, a rotating shaft and a hook, wherein the reduction motor and the cam divider can drive the rotating shaft to rotate intermittently, and the multiple groups of hooks provided on the rotating shaft hook up the debris and rotate and throw it to the next screening process;

[0023] By setting a pressure detection sensor and an angle detection sensor on the swing rod, it is possible to detect and determine whether there are large debris in the raw coal. When the pressure detection sensor detects the pressure value of the swing rod and the angle detection sensor detects the moving angle of the swing rod, the movement state of the swing rod is adjusted by the oil cylinder of the grate screening mechanism, and the reduction motor and cam divider of the rotary roller hook claw screening mechanism intermittently drive the hook claw to move, hook up the debris and perform rotary throwing to remove the debris.

[0024] Preferably, in step 4, the large debris is transported to the recycling box by a belt-type debris discharging mechanism;

[0025] Among them, the strip-type debris discharge mechanism includes a motor, a roller and multiple strips arranged at equal intervals. The motor drives the strips to rotate through the rollers. The coal blocks in the debris fall into the silo below through the gaps between the strips. Large debris is intercepted on the strips and transported to the recycling box.

[0026] The beneficial technical effects of the present invention are:

[0027] The present invention provides a control method for removing impurities from raw coal. The method filters out coal powder in the raw coal through a feed primary screening mechanism, and evenly disperses the coal through a set leveler to prevent excessive accumulation of coal and jamming of printing equipment. The belt-type iron removal mechanism removes metal impurities in the coal, and the grate screening mechanism cooperates with the rotary roller hook-claw screening mechanism to remove large impurities in the coal blocks. Finally, the impurities are transported through a strip-type impurity discharge mechanism. The control method can not only remove iron metal impurities such as anchor rods and metal meshes in the raw coal, but also remove large impurities such as stones, thereby effectively improving the quality of the raw coal, and at the same time can avoid equipment damage caused by impurities, ensuring the normal operation of the coal mine. mining operations; in addition, the speed detection sensor and the coal flow sensor are used to detect the speed and flow of the coal to determine the location of the coal, and the metal detector is used to detect whether there are metal debris in the raw coal to decide whether to start the strip-type iron removal mechanism for iron removal. The pressure detection sensor and the angle detection sensor can be set to detect whether there are large debris in the raw coal to decide whether to start the roller hook claw screening mechanism for rotary throwing treatment of the debris. The entire debris removal process has a high degree of intelligence, which can not only ensure the debris removal efficiency and improve the quality of raw coal, but also ensure the personal health and safety of the staff, which meets the development requirements of modern industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Flow chart of a control method for removing impurities from raw coal in an embodiment of the present invention;

[0029] Figure 2 It is a front view of the impurity removal device in the embodiment of the present invention;

[0030] Figure 3 A three-dimensional diagram of an impurity removal device in an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the structure of the feed primary screening mechanism in an embodiment of the present invention;

[0032] Figure 5 It is a structural schematic diagram of a belt-type iron removal mechanism in an embodiment of the present invention;

[0033] Figure 6 It is a schematic diagram of the assembly of the grate screening mechanism, the rotary roller hook-claw screening mechanism and the knife cleaning mechanism in the embodiment of the present invention;

[0034] Figure 7 It is a schematic diagram of the assembly of the grate-type screening mechanism and the rotary roller hook-claw screening mechanism in the embodiment of the present invention;

[0035] Figure 8 It is a schematic diagram of the assembly of the rotary roller hook-claw type screening mechanism and the knife cleaning mechanism in the embodiment of the present invention;

[0036] Fig. 9It is a structural schematic diagram of a strip-type trash discharging mechanism in an embodiment of the present invention;

[0037] Among them, 1-feeding primary screening mechanism: 11-feeding funnel, 111-guide plate, 12-mixer;

[0038] 2-belt type iron removal mechanism: 21-debris transfer belt, 22-electromagnet;

[0039] 3-grate screening mechanism: 31-square tube, 32-swing rod, 33-driving block, 34-stop block;

[0040] 4-Rotary roller hook type screening mechanism: 41-reduction motor, 42-cam divider, 43-rotating shaft, 44-hook;

[0041] 5-cleaning mechanism: 511-first cleaning scraper, 521-slide rail, 522-sliding block, 523-second cleaning scraper;

[0042] 6-strip type trash removal mechanism: 61-roller, 62-strip;

[0043] 7- Recycling bin. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical scheme and beneficial effects of the present invention more clearly understood, the present invention is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. Certain embodiments of the present invention will be described more comprehensively with reference to the accompanying drawings, in which some but not all embodiments will be shown. In fact, the various embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the embodiments described herein; rather, these embodiments are provided so that the present invention meets applicable legal requirements.

[0045] In the description of the present invention, it should be noted that the terms "inside", "outside", "upper", "lower", "front", "back" and the like indicate directions or positional relationships based on directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0046] refer to Figure 1 As shown, in an embodiment of the present invention, a control method for removing impurities from raw coal is provided, which specifically includes the following steps:

[0047] Step 1: First, the raw coal is preliminarily screened to remove fine coal powder and evenly distribute the coal flow. The raw coal after the fine coal powder is removed enters the next stage of metal debris removal process;

[0048] Specific, combined Figure 4 As shown, the coal powder in the raw coal is screened out by the feed primary screening mechanism 1, wherein the feed primary screening mechanism 1 mainly includes a feed funnel 11 and a material distributor 12. A guide plate 111 is arranged inside the feed funnel 11, and a screening groove is provided on the guide plate 111. The coal powder with a smaller particle size falls through the screening groove of the guide plate 111, and the lump raw coal enters the next level of transportation process through the discharge port of the feed funnel 11.

[0049] At the same time, combined Figure 4 As shown, a leveler 12 is provided at the rear side of the feed port and the discharge port of the feed hopper 11. The leveler 12 includes a connecting shaft and a plurality of swing hooks equidistantly arranged on the connecting shaft. The raw coal collides with the swing hooks of the leveler 12, so that the raw coal can be evenly dispersed, which can prevent the accumulation of coal materials and cause blockage of the device, and also provide favorable conditions for the next step of iron removal operation.

[0050] Step 2: In the metal impurity removal process, when the raw coal is being transported, the material identifier is used to detect and remove the metal impurities in the raw coal. The raw coal after the metal impurities are removed is transported to the next level of impurity removal and screening process.

[0051] Specific, combined Figure 2 and Figure 3 As shown, the transportation of lump raw coal is achieved through the coal conveyor belt transmission mechanism, and when the material identifier detects that metal debris is mixed in the raw coal, the belt-type iron removal mechanism 2 is started to remove the metal debris mixed in the raw coal.

[0052] The material identifier includes a metal detector, a coal flow sensor and a speed detection sensor. The metal detector determines the presence and size of metal on the surface of the coal conveyor belt transmission mechanism through the induction data of the electromagnetic pulse wave, and the detection data of the coal flow sensor and the speed detection sensor assist in determining the instantaneous coal flow and detecting the instantaneous material position. When the metal detector detects the presence of metal debris on the surface of the coal conveyor belt transmission mechanism, it cooperates with the coal flow sensor and the speed detection sensor to detect the location of the metal debris, and at the same time starts the belt type debris removal mechanism 2 to remove the debris.

[0053] Combination Figure 1 , Figure 2 and Figure 5 As shown, a belt type iron removal mechanism 2 is provided above the coal conveying belt transmission mechanism for removing metal impurities in the raw coal. The belt type iron removal mechanism 2 comprises an impurity transport belt 21, a belt motor and an electromagnet 22, wherein the electromagnet 22 is arranged in the interlayer space of the impurity transport belt 21.

[0054] According to the detection results of the three groups of sensors of the material identifier, the electromagnetic excitation current is accurately turned on, and the metal debris is adsorbed onto the debris transfer belt 21 by using the electromagnet to excite magnetism; at the moment of iron-coal separation, the belt motor of the belt-type iron removal mechanism 2 is turned on, and its rotating debris transfer belt 21 will inertialy throw the metal objects adsorbed on the belt surface away from the belt, thereby realizing iron removal control.

[0055] Step 3: In the impurity removal and screening process, the coal flow is screened. The coal flow that meets the falling requirements falls under the action of gravity and kinetic energy, and the large coal blocks and debris that cannot fall are further screened and impurities removed;

[0056] Specific, combined Figure 7 As shown, the large debris in the raw coal is screened out by setting a grate screening mechanism 3, wherein the grate screening mechanism 3 includes an oil cylinder, a square tube 31, a swing rod 32, a driving block 33 and a stopper 34, wherein the square tube 31 is arranged horizontally, and both ends of the square tube 31 are connected with a driving block 33 with an ear-shaped outer contour, and the oil cylinder drives the square tube 31 to rotate by connecting the driving block 33, and a plurality of swing rods 32 arranged at equal intervals are arranged on the square tube 31, and the swing rod 32 swings with the square tube 31, and the swing amplitude and frequency are controlled by the oil cylinder, which can prevent large debris from being stuck in the gap between the swing rods 32. The coal blocks fall into the silo below through the gap of the swing rod 32 for storage, and the large debris is trapped on the swing rod 32 to wait for subsequent hooking and spinning operations. At the same time, a plurality of blocks 34 are also provided on the square tube 31, wherein a block 34 is provided on both sides of the end of each swing rod 32, and the block 34 can prevent the debris from rolling back to the position between the grate screening mechanism 3 and the coal conveyor belt transmission mechanism when the swing rod 32 is lifted upward, thereby causing damage to the equipment. At the same time, the outer contour of the block 34 is in a semicircular arc shape, and when the coal block rolls freely from the coal conveyor belt transmission mechanism, the coal block or debris can fall on the swing rod 32 more smoothly because the contour arc of the block 34 is tangent to the falling direction of the coal block.

[0057] Combination Figure 7 As shown, by setting the rotary roller hook type screening mechanism 4, the oversized or overweight debris can be hooked and thrown to the strip type debris discharging mechanism 6, wherein the rotary roller hook type screening mechanism 4 mainly includes a reduction motor 41, a cam divider 42, a rotating shaft 43 and a hook 44. The reduction motor 41 and the cam divider 42 can provide power to drive the rotating shaft 43 to rotate intermittently, and the multiple groups of hooks 44 arranged on the rotating shaft 43 throw the large debris into the next screening process.

[0058] Specific, combined Figure 7As shown, the reduction motor 41 is arranged on the base, the reduction motor 41 is connected to the cam divider 42, the cam divider 42 is connected to the rotating shaft 43, and a plurality of groups of hooks 44 are arranged on the rotating shaft 43, wherein three hooks 44 form a group, and the three hooks 44 in the same group are on the same plane, and the interval angle between the hooks 44 in the same group is 120°. A spacing sleeve is arranged between two adjacent groups of hooks 44, which can effectively separate the hooks 44. The individual hooks 44 of each group of hooks correspond to each other in position, and three rows of hook groups arranged axially along the rotating shaft 43 are formed as a whole.

[0059] When larger debris is trapped on the swing rod 32, the reduction motor 41 is turned on to provide power, and the cam divider 42 is used to realize intermittent rotation of the rotating shaft 43, so that the hook 44 provided on the rotating shaft 43 completes the spinning and throwing of the large debris every time it rotates 120°, that is, every time it rotates, a row of hook groups simultaneously completes the process of hooking up the debris above the swing rod 32 and spinning and throwing it to remove the debris. At the same time, it can also prevent the situation that the debris is not completely thrown out by the hook 44 before it is completely in place, and the whole spinning and throwing process is more controllable.

[0060] By setting a pressure detection sensor and an angle detection sensor on the swing rod 32 to detect whether there are large debris in the raw coal, by setting a pressure detection sensor to detect the pressure value of the swing rod 32, and by setting an angle detection sensor to detect the moving angle between the swing rod 32 and the horizontal plane, the obtained data is compared and analyzed with the given preset value to determine when to start the grate screening mechanism 3 and the rotary roller hook type screening mechanism 4. By controlling the oil cylinder of the grate screening mechanism 3 to adjust the movement state (vibration or swing or stillness) of the swing rod 32, the reduction motor 41 and the cam divider 42 of the rotary roller hook type screening mechanism 4 intermittently drive the hook 44 to move, hook up the debris and perform rotary throwing to remove the debris.

[0061] At the same time, combined Figure 8As shown, a cleaning mechanism 5 for cleaning the hook 44 is also arranged above the rotary roller hook claw screening mechanism 4, and the cleaning mechanism 5 includes a first cleaning scraper 511 arranged on the first assembly shaft, and the position of the first assembly shaft is relatively fixed. The cleaning mechanism also includes a second cleaning scraper 523 arranged on the second assembly shaft, wherein the second assembly shaft is connected to the slider 522 through a bearing seat, and a slide rail 521 is arranged at the bottom of the slider 522. The second cleaning scraper 523 can move along the slide rail 521 to adjust the position, and the slider 522 is driven to move by the cylinder, thereby driving the second cleaning scraper 523 to slide back and forth periodically, cleaning the entangled debris on the hook 44, which helps to complete the next rotary throwing operation smoothly and achieve a continuous non-blocking operation state. When the hook 44 rotates, it generates relative motion with the first cleaning scraper 511 and the second cleaning scraper 523, so that the soft debris such as the rope wound on the hook 44 can be cut to ensure the normal operation of the rotary roller hook claw screening mechanism 4 and complete the throwing and removing of large debris. The number of the first cleaning scraper 511 and the second cleaning scraper 523 is equal to the number of the hook claw groups, which can ensure that each hook claw 44 can be cleaned, prevent the occurrence of blockage, and ensure the smooth progress of the rotary throwing and debris removal operation.

[0062] Step 4: further screen out the carried coal lumps from the debris obtained in step 3, and transport the large coal lumps and debris to the recovery box 7.

[0063] Specific, combined Fig. 9 As shown, large debris is transported to the recovery box 7 through a belt-type debris discharging mechanism 6, wherein the belt-type debris discharging mechanism 6 includes a motor, a roller 61 and a plurality of belts 62 arranged at equal intervals. The motor drives the belt 62 to operate through the roller 61, and the raw coal falls into the silo below through the gaps between the belts 62, while the large debris is trapped on the belt 62 and transported to the recovery box 7.

[0064] The present invention provides a control method for removing impurities from raw coal. The coal powder in the raw coal is filtered out by a feed primary screening mechanism 1, and the coal is evenly dispersed by a set leveler 12 to prevent the coal from being excessively accumulated and causing the device to jam. The metal impurities in the coal are removed by a belt-type iron removal mechanism 2, and large impurities in the coal blocks are removed by the cooperation of a grate-type screening mechanism 3 and a rotary roller hook-claw screening mechanism 4. Finally, the impurities are transported by a strip-type impurity removal mechanism 6. The control method can remove iron metal impurities such as anchor rods and metal meshes in the raw coal, and can also remove large impurities such as stones, effectively improving the quality of the raw coal. At the same time, it can also avoid damage to the device caused by accumulation of impurities, thereby ensuring normal mining operations in the coal mine. At the same time, by cooperating with the speed detection sensor and the coal flow sensor to detect the speed and flow of the coal material to determine the position of the coal material, the metal detector and the material identification sensor are used to detect whether there are metal impurities in the raw coal, so as to decide whether and when to start the belt type iron removal mechanism 2 for iron removal operation, which can achieve the purpose of removing metal impurities in the raw coal. At the same time, only when the metal detector detects metal impurities and the metal-containing raw coal is about to pass through the belt type iron removal mechanism 2, the belt type iron removal mechanism 2 will be operated again, which can relatively save the operating cost; by setting the pressure detection sensor and the angle detection sensor, it can detect whether there are large impurities in the raw coal, so as to start the rotary roller hook claw type screening mechanism 4 to hook up the impurities and perform rotary throwing to remove impurities. The whole impurity removal process has a high degree of intelligence, which meets the development requirements of modern industry. The present invention enables the coal preparation plant to realize the automation of graded impurity removal, reduce (or do not need) manual participation, reduce or reduce the amount of impurities handled by the downstream process equipment of the production line, help to realize the function of raw coal classification, and reduce the failure rate of the transportation system and equipment caused by impurities. By optimizing the equipment control method, the occurrence of blockage can be effectively reduced, production line stoppages caused by equipment failures can be avoided, and coal mine production efficiency can be improved.

[0065] Of course, the specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific 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 in the scope of protection of the present invention.

Claims

1. A control method for removing impurities from raw coal, characterized in that: The steps include: Step 1: First, the raw coal is preliminarily screened to remove fine coal powder and evenly distribute the coal flow. The raw coal after the fine coal powder is removed enters the next stage of metal debris removal process; Step 2: In the metal impurity removal process, when the raw coal is being transported, the material identifier is used to detect and remove the metal impurities in the raw coal. The raw coal after the metal impurities are removed is transported to the next level of impurity removal and screening process. Step 3: In the impurity removal and screening process, the coal flow is screened. The coal flow that meets the falling requirements falls under the action of gravity and kinetic energy, and the large coal blocks and debris that cannot fall are further screened and impurities removed; Step 4: further screen out the carried coal lumps from the debris obtained in step 3, and transport the large coal lumps and debris to a recovery box.

2. A control method for removing impurities from raw coal according to claim 1, characterized in that: In the step 1, the raw coal is preliminarily screened by using a feed pre-screening mechanism; Among them, the feed initial screening mechanism includes a feed funnel and a material leveler. A guide plate is arranged inside the feed funnel, and a screening groove is provided on the guide plate. The coal powder with a smaller particle size falls through the screening groove of the guide plate, and the lump raw coal enters the next level of transportation process through the discharge port of the feed funnel; At the same time, a refining device is arranged at the rear side of the feed port and the discharge port of the feed hopper. The raw coal collides with the refining device, so that the raw coal can be evenly dispersed, reducing the viscosity of the coal flow.

3. A control method for removing impurities from raw coal according to claim 1, characterized in that: In step 2, the lump raw coal is transported by the coal conveyor belt transmission mechanism, and when the material identifier detects that the raw coal contains metal impurities, the belt type iron removal mechanism is started to remove the metal impurities mixed in the raw coal; The material identifier includes a metal detector, a coal flow sensor and a speed detection sensor; Among them, the metal detector determines the presence and size of metal on the surface of the coal conveyor belt transmission mechanism through the induction data of electromagnetic pulse waves, and the detection data of the coal flow sensor and speed detection sensor assist in determining the instantaneous coal flow and detecting the instantaneous material position; When the metal detector detects the presence of metal debris on the surface of the coal conveyor belt transmission mechanism, the coal flow sensor and the speed detection sensor are used to detect the position of the metal debris, and the belt type debris removal mechanism is started to remove the debris.

4. A control method for removing impurities from raw coal according to claim 3, characterized in that: In the step 2, a belt-type iron removal mechanism is provided above the coal conveying belt transmission mechanism; the belt-type iron removal mechanism comprises a debris transport belt, a belt motor and an electromagnet, wherein the electromagnet is provided in the interlayer space of the debris transport belt; According to the detection results of the three sets of sensors of the material identifier, the electromagnetic excitation current is accurately turned on, and the electromagnet is used to excite magnetism to adsorb metal debris onto the debris transfer belt; at the moment of iron-coal separation, the belt motor of the belt-type iron removal mechanism is turned on, and its rotating debris transfer belt will inertia throw the metal objects adsorbed on the belt surface away from the belt, thereby realizing iron removal control.

5. A control method for removing impurities from raw coal according to claim 1, characterized in that: In step 3, large debris in the raw coal is screened out by setting a grate screening mechanism, wherein the grate screening mechanism includes an oil cylinder, a square tube and a swing rod, wherein the oil cylinder drives the square tube to rotate, and a plurality of swing rods arranged on the square tube rotate with the square tube, which can prevent large debris from being stuck in the gap between the swing rods, and the coal blocks fall into the silo below through the gap between the swing rods for storage, and the large debris is trapped on the swing rod waiting for the spinning and throwing operation; The rotary roller hook type screening mechanism is provided to complete the rotary throwing and impurity removal operation of large debris, wherein the rotary roller hook type screening mechanism includes a reduction motor, a cam divider, a rotating shaft and a hook, wherein the reduction motor and the cam divider can drive the rotating shaft to rotate intermittently, and the multiple groups of hooks provided on the rotating shaft hook up the debris and rotate and throw it to the next screening process; By arranging a pressure detection sensor and an angle detection sensor on the swing rod to detect whether there are large debris in the raw coal, the pressure detection sensor detects the pressure value of the swing rod and the angle detection sensor detects the moving angle of the swing rod, thereby controlling the oil cylinder of the grate screening mechanism to adjust the movement state of the swing rod, and the reduction motor and cam divider of the rotary roller hook claw screening mechanism intermittently drive the hook claw to move, hook up the debris and spin it to remove the debris.

6. A control method for removing impurities from raw coal according to claim 1, characterized in that: In step 4, the large debris is transported to the recycling box by a strip-type debris discharging mechanism; Among them, the strip-type debris discharge mechanism includes a motor, a roller and multiple strips arranged at equal intervals. The motor drives the strips to rotate through the rollers. The coal blocks in the debris fall into the silo below through the gaps between the strips. Large debris is intercepted on the strips and transported to the recycling box.

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