Electrostatic separation device and method with combined atomization modification

Abstract

The application discloses a kind of combined atomization modified electric separation device and method, belong to dry electrostatic separation technical field, to solve the problem of low product recovery efficiency caused by low separation efficiency and low separation accuracy in prior art.The device includes air supply unit, air supply pipeline, feeding unit and modified atomization unit;Air supply unit and air supply pipeline are connected, the discharge port of feeding unit and the gas outlet of modified atomization unit are connected with air supply pipeline;Air supply unit is used to provide airflow from air supply unit to air supply pipeline, feeding unit is used to provide selected particles, modified atomization unit is used to provide atomized surface modifier, selected particles and atomized surface modifier are mixed in air supply pipeline.The application can be used for the electric selection of selected particles, and can improve the efficiency and separation effect of selected particles tribocharging.

Description

Technical Field

[0001] This invention belongs to the field of dry electrostatic separation technology, and specifically relates to an electrostatic separation device and method with combined atomization modification. Background Technology

[0002] Triboelectric separation is a dry separation technology that utilizes the contact, collision and friction between mineral particles or between mineral particles and a friction medium to generate charges of different sizes and opposite polarities. These charges are then introduced into a high-voltage electric field. Due to the different charges on the particles, their trajectories are significantly different, thus separating the two minerals.

[0003] Compared to wet mineral processing methods, triboelectric separation technology has the advantages of simple process, low investment cost, easy operation, and low pollution. It also has high product recovery rate and good sorting effect, and has been widely used in the sorting of minerals, crops and waste plastics. Recently, there have also been many reports on the recycling of solid electronic waste.

[0004] However, as the particle size of the material to be sorted decreases, the surface area increases, and the surface energy rises, making it easy for particles to spontaneously agglomerate. This agglomeration reduces the flowability of the particles, decreasing the probability of collision with the friction medium and the effective contact area during triboelectric charging. The reduced efficiency of triboelectric charging leads to insufficient offset trajectory in the electric field, resulting in decreased sorting efficiency.

[0005] Furthermore, during the sorting process, the complexity of particle charge distribution results in particles with varying charge sizes within the triboelectrically charged particle group. When these charged particles with different charge sizes enter a single-field electrostatic sorting field, particles with lower charge do not deflect sufficiently, while particles with higher charge deflect prematurely, collide with the electrode plates, and bounce into the wrong collection tank. This leads to unsatisfactory product collection and affects product recovery efficiency. Summary of the Invention

[0006] Based on the above analysis, the present invention aims to provide a combined atomization-modified electrostatic separation device and method to solve the problems of low product recovery efficiency caused by reduced separation efficiency and low separation accuracy in the prior art.

[0007] The objective of this invention is mainly achieved through the following technical solutions.

[0008] This invention provides a combined atomization modification electrostatic separator, comprising an air supply unit, an air supply pipeline, a feeding unit, and a modification atomization unit; the air supply unit and the air supply pipeline are connected, and the outlet of the feeding unit and the air outlet of the modification atomization unit are both connected to the air supply pipeline; the air supply unit is used to provide airflow from the air supply unit to the air supply pipeline, the feeding unit is used to provide particles to be selected, and the modification atomization unit is used to provide atomized surface modifiers; the particles to be selected and the atomized surface modifiers are mixed in the air supply pipeline.

[0009] Furthermore, the air supply unit includes a fan and an air receiver. The air outlet of the fan is connected to the air inlet of the air receiver, and the air outlet of the air receiver is connected to the air inlet of the air supply duct.

[0010] Furthermore, a flow meter is installed on the air supply duct; the flow meter detects the real-time air supply flow data in real time and determines whether the real-time air supply flow data is within the threshold range. If not, the real-time air supply flow is adjusted through the air receiver until the real-time air supply flow is within the threshold range.

[0011] Furthermore, the feeding unit includes a storage tank and a vibrator. The outlet of the storage tank is connected to the air supply pipe, and the vibrator is used to drive the storage tank to reciprocate.

[0012] Furthermore, the storage trough is located above the air supply duct, the outlet of the storage trough is located at the bottom of the storage trough, and the outlet of the storage trough is connected to the air supply duct through a feeding pipe, which is inclined.

[0013] Furthermore, the modified atomization unit includes an atomizer and a storage chamber. The storage chamber is used to store the atomized surface modifier. The outlet of the atomizer is connected to the inlet of the storage chamber. The air inlet and outlet of the storage chamber are both connected to the air supply duct. Along the air supply direction, the flow meter, the outlet of the feed pipe, the air inlet of the storage chamber, and the air outlet of the storage chamber are arranged in sequence.

[0014] Furthermore, it also includes a concentration detection controller for detecting the concentration of the surface modifier; there are two concentration detection controllers, one of which is located on the inner wall of the storage chamber and the other is located at the air outlet of the air supply duct; the concentration detection controller detects the real-time surface modifier concentration data in real time and determines whether the real-time surface modifier concentration data has reached the threshold. If it has not reached the threshold, the real-time surface modifier concentration data is adjusted through the atomizer until the real-time surface modifier concentration data reaches the threshold.

[0015] Furthermore, both the air inlet and outlet of the storage compartment are connected to the air supply duct via connecting pipes, and a pressure stabilizing plate is installed on the connecting pipes.

[0016] Furthermore, the voltage stabilizer includes a plate body with multiple through holes.

[0017] The present invention also provides a combined atomization modification electrostatic separation method, wherein the above-mentioned combined atomization modification electrostatic separation device is used for electrostatic separation.

[0018] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects.

[0019] A) The combined atomization modification electrostatic separation device provided by the present invention combines atomization modification technology and particle dispersion technology with triboelectric charging separation technology to solve the problem of unsatisfactory triboelectric charging separation effect of candidate particles in industry, and improve the efficiency of triboelectric charging and separation effect of candidate particles.

[0020] B) The electrostatic separation device for combined atomization modification provided by this invention, on the one hand, uses airflow provided by an air supply unit as a conveying medium, which not only disperses the particle clusters formed by the particles to be selected, enhancing the flowability of the particle clusters, but also carries the atomized surface modifier to modify the surface of the particles to be selected, so that the surface modifier coats the particle clusters to achieve the purpose of dry modification. This technology simplifies the process flow and is flexible and easy to adjust. On the other hand, during the surface modification process of the particles to be selected, by selecting a suitable surface modifier, not only can the charge difference between the particles to be selected be increased, but the agglomeration tendency between the particles to be selected can also be changed.

[0021] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained through the embodiments described and the accompanying drawings, which are particularly pointed out. Attached Figure Description

[0022] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0023] Figure 1 A schematic diagram of the combined atomization modification electrostatic separation device provided by the present invention;

[0024] Figure 2 A cross-sectional view of the voltage regulator plate in the combined atomization modification electrostatic separator provided by the present invention;

[0025] Figure 3 A top view of the rotating friction needle wheel in the electrostatic separation device for combined atomization modification provided by the present invention;

[0026] Figure 4 This is a top view of the umbrella-shaped feeder in the combined atomization modification electrostatic separator provided by the present invention.

[0027] Figure label:

[0028] 1-Fan; 2-Vibrating feeder; 3-Feeding pipe; 4-Flow meter; 5-Feeding regulator; 6-Air supply duct; 7-Concentration detection controller; 8-Rotary motor; 9-Rotating shaft; 10-Air jacket; 11-Atomizer; 12-Rotating friction pinwheel; 121-Needle seedling; 13-Pressure stabilizing plate; 14-Storage bin; 15-Umbrella spreader; 151-Fixed disc; 152-Helical blade; 16-Friction medium cylinder; 17-Grading electrode plate; 18-Outer shell; 19-Power supply; 20-Collection tank; 21-Outlet air regulator. Detailed Implementation

[0029] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0030] This invention provides a combined atomization-modified electrostatic separator, see [link to related document]. Figure 1 It includes an air supply unit, a feeding unit, a modified atomizing unit, a triboelectric charging unit, and an electrostatic sorting unit. The air supply unit, the air supply duct 6, the triboelectric charging unit, and the electrostatic sorting unit are connected in sequence. The outlet of the feeding unit and the air outlet of the modified atomizing unit are both connected to the air supply duct 6. The air supply unit is used to provide airflow from the air supply unit to the triboelectric charging unit. The feeding unit is used to provide the particles to be selected. The modified atomizing unit is used to provide atomized surface modifier. The particles to be selected and the atomized surface modifier are mixed in the air supply duct 6 and enter the triboelectric charging unit under the airflow.

[0031] During sorting, a surface modifier is atomized to modify the surface of the particles to be selected (e.g., fine particles), thereby increasing the charge difference between the particles and changing their agglomeration tendency. In practical applications, a suitable surface modifier can be selected according to the type of particles to be selected. The modified particles are transported by the airflow of the air supply unit into the triboelectric charging unit, where they are charged to become fully charged particles and enter the electrostatic sorting unit. Charged particles of different polarities are deflected by the lateral action of electric fields of different magnitudes and directions and fall into different collection tanks 20, thus achieving the separation of the particles to be selected.

[0032] Compared with existing technologies, the combined atomization modification electrostatic separation device provided by the present invention combines atomization modification technology and particle dispersion technology with triboelectric charging separation technology to solve the problem of unsatisfactory triboelectric charging separation effect of candidate particles in industry, and improve the efficiency of triboelectric charging and separation effect of candidate particles.

[0033] Specifically, on the one hand, using the airflow provided by the air supply unit as the transport medium can not only disperse the particle clusters formed by the candidate particles, enhancing their flowability, but also carry atomized surface modifiers to modify the surface of the candidate particles. This allows the surface modifiers to coat the particle clusters, achieving the purpose of dry modification. This technology simplifies the process flow and is flexible and easy to adjust. On the other hand, during the surface modification process of the candidate particles, by selecting appropriate surface modifiers, not only can the charge difference between the candidate particles be increased, but the agglomeration tendency of the candidate particles can also be changed.

[0034] Considering that the modification of the selected particles is mainly carried out in the air supply duct 6, in order to ensure the sufficiency of the modification of the selected particles, the diameter of the air supply duct 6 is 0.12-0.16m, the length is 5-7m, and the distance between the connection point of the modified atomizing unit and the connecting duct and the connection point of the connecting duct and the triboelectric unit is 3-5m.

[0035] In order to control the flow rate of the particles to be selected into the triboelectric charging unit, the air supply duct 6 is provided with an air outlet regulating component 21 that partially covers the outlet of the air supply duct 6. For example, a stainless steel slab. By adjusting the area of ​​the air outlet regulating component 21 covering the outlet, the size of the outlet opening of the air supply duct 6 can be controlled, thereby controlling the flow rate of the particles to be selected into the triboelectric charging unit.

[0036] To prevent the particles to be selected from becoming pre-charged due to friction with the air supply duct 6 during the transport process, the air supply duct 6 is grounded by a wire.

[0037] Specifically, the air supply unit includes a fan 1 and an air receiver 10. The air outlet of the fan 1 is connected to the air inlet of the air receiver 10, and the air outlet of the air receiver 10 is connected to the air inlet of the air supply duct 6.

[0038] To detect the air supply flow rate, a flow meter 4 is installed on the aforementioned air supply duct 6. The flow meter 4 monitors the real-time air supply flow rate data and determines whether it falls within a threshold range. If not, the air receiver 10 adjusts the real-time air supply flow rate until it falls within the threshold range, thereby regulating the feed concentration and the collision intensity of the target particles within the air supply duct 6. For example, the air supply flow rate is 100–1000 m³ / h. 3 / h, with a supply air pressure of 0.1~0.6MPa.

[0039] For example, the feeding unit is a vibrating feeder 2, which includes a storage trough and a vibrator. The outlet of the storage trough is connected to the air supply pipe 6. The vibrator drives the storage trough to reciprocate at a certain angle. The vibration frequency of the storage trough is controlled by adjusting the frequency of the vibrator, thereby controlling the feeding speed. For example, the vibration frequency is 2000-5000Hz, and the maximum amplitude is ±13mm.

[0040] To enable automatic feeding, the aforementioned storage trough is positioned above the air supply duct 6, with its outlet located at the bottom. The outlet is connected to the air supply duct 6 via a feed pipe 3, which is inclined and has its inlet parallel to the bottom of the storage trough. This allows the particles to slide directly into the air supply duct 6 under the influence of gravity, aided by the vibrator.

[0041] In addition, the feeding speed can be adjusted by the following method: a feeding adjustment component 5 is provided at the outlet of the feeding pipe 3, which partially covers the outlet of the feeding pipe 3. For example, a stainless steel insert. By adjusting the area of ​​the feeding adjustment component 5 covering the feeding port, the size of the outlet of the feeding pipe 3 can be controlled, thereby controlling the feeding speed.

[0042] Specifically, the modified atomizing unit includes an atomizer 11 (e.g., an ultrasonic atomizer 11) and a storage chamber 14. The outlet of the atomizer 11 is connected to the inlet of the storage chamber 14. The air inlet and outlet of the storage chamber 14 are both connected to the air supply duct 6. Along the air supply direction, the flow meter 4, the outlet of the feed pipe 3, the air inlet and outlet of the storage chamber 14 are arranged in sequence. The storage chamber 14 is used to store the atomized surface modifier. The maximum charge is 100L. The maximum atomization speed of the atomizer 11 is 500L / h.

[0043] To enable real-time detection of the surface modifier concentration, the aforementioned combined atomization modification electrostatic separation device further includes a concentration detection controller 7 for detecting the surface modifier concentration. For example, two concentration detection controllers 7 are used, one located on the inner wall of the storage chamber and the other at the air outlet of the air supply duct 6. In this way, the concentration detection controller 7 detects the real-time surface modifier concentration data and determines whether the real-time surface modifier concentration data has reached a threshold. If not, the atomizer 11 adjusts the real-time surface modifier concentration data until it reaches the threshold. This method allows for real-time detection of the surface modifier concentration, controlling the operating time of the atomizer 11 according to the set concentration threshold. This prevents the surface modifier concentration from being too high, causing the selected particles to clump together, or from being too low, causing insufficient modification.

[0044] For example, the air inlet and air outlet of the storage chamber 14 are both connected to the air supply pipe 6 via connecting pipes. A pressure stabilizing plate 13 is provided on the connecting pipe. The pressure stabilizing plate 13 can stabilize the airflow entering the storage chamber 14 and the airflow exiting the storage chamber 14, so that the atomized surface modifier can enter the air supply pipe 6 under the delivery of a stable airflow to perform surface modification on the selected particles.

[0045] Specifically, the aforementioned voltage regulator plate 13 includes a plate body with multiple through holes, see [reference]. Figure 2 The opening ratio of the voltage regulator plate 13 is adjustable. In practical applications, the opening ratio can be adjusted by partially blocking the through holes. The concentrated airflow is dispersed into multiple airflows through the through holes, thereby achieving voltage stabilization.

[0046] Specifically, the structure of the triboelectric charging unit includes a triboelectric medium cylinder 16, a rotary motor 8, a rotary shaft 9, a rotary friction pinwheel 12, and a canopy spreader 15. The inlet of the triboelectric medium cylinder 16 is connected to the outlet of the air supply duct 6, and the outlet of the triboelectric medium cylinder 16 is connected to the inlet of the electrostatic sorting unit. The rotary shaft 9, the rotary friction pinwheel 12, and the canopy spreader 15 are located inside the triboelectric medium cylinder 16. One end of the rotary shaft 9 is fixedly connected to the rotary motor 8, and the other end passes through the rotary friction pinwheel 12 and is fixedly connected to the canopy spreader 15. The rotary motor 8 drives the rotary friction pinwheel 12 and the spreader to rotate around the rotary shaft 9 at a speed of 50–500 r / min. In this way, the modified particles to be selected in the air supply duct 6 enter the triboelectric medium cylinder 16, and are triboelectrically charged by the rotation of the rotary friction pinwheel 12. The charged particles then pass through the canopy spreader 15 and enter the electrostatic sorting unit evenly. Through this triboelectric charging unit structure, during the triboelectric charging process of the particles to be selected, the particles undergo multiple levels of triboelectric charging, including impact from the rotating friction pin wheel 12, rebound onto the inner wall of the friction medium cylinder 16, movement and spreading on the umbrella-shaped spreader 15, and sliding along the friction medium cylinder 16. This ensures that the particles to be selected are fully charged. Furthermore, the high-speed rotating friction pin wheel 12 can also use mechanical force to strike the particle group, overcoming the adhesion between the particles and enhancing their flowability, thereby improving the agglomeration phenomenon.

[0047] For example, the air outlet direction of the air supply duct 6 is perpendicular to the axial direction of the rotating shaft 9. In this way, during the operation of introducing the modified candidate particles, the modified candidate particles are fed into the friction medium cylinder 16 under the lateral force of the airflow. This not only allows the collision intensity between the candidate particles and the rotating friction pinwheel 12 and the inner wall of the friction medium cylinder 16 to be adjusted by regulating the airflow speed, but also does not shorten the charging time of the candidate particles in the friction medium cylinder 16, thereby effectively improving the charging efficiency of the candidate particles in the friction medium cylinder 16.

[0048] Specifically, the friction medium cylinder 16 comprises a cylindrical cylinder and an inverted conical cylinder connected sequentially from top to bottom (e.g., welded). The inlet of the friction medium cylinder 16 is located on the side wall of the cylindrical cylinder, and the outlet of the friction medium cylinder 16 is located at the bottom end of the conical cylinder. The rotating shaft 9, the rotating friction pinwheel 12, and the umbrella-shaped feeder 15 are all located within the cylindrical cylinder. With this structure, the friction medium cylinder 16 effectively increases its internal volume by using a cylindrical cylinder, facilitating the accommodation of the rotating shaft 9, the rotating friction pinwheel 12, and the umbrella-shaped feeder 15. Furthermore, the inverted conical cylinder appropriately reduces the movement speed of the particles to be selected, prolonging their friction and descent time, thus allowing the particles to become fully charged.

[0049] To further improve the charging effect of the selected particles, the structure of the rotating friction pinwheel 12 specifically includes multiple charged layers arranged axially along the rotation axis 9, see [reference needed]. Figure 3 There are gaps between adjacent charged layers. Each charged layer includes multiple needles 121 arranged radially around the rotating shaft 9. There are gaps between each needle 121, and the needles 121 are evenly distributed. The axis of each needle 121 is perpendicular to the axis of the rotating shaft 9, and there is a gap between the tip of the needle 121 and the inner wall of the friction medium cylinder 16. Compared with existing rotating friction rods, this rotating friction needle wheel 12 has densely and evenly distributed needles 121. Applying the principle of dynamic filtration and penetration probability, the needles 121 can perform multi-level impact collisions on the selected particle group. During the process of fully charging the selected particles, it also has a three-dimensional dispersion effect, ensuring that the sprinkled material does not clump.

[0050] To improve fabric uniformity, the umbrella fabric spreader 15 includes a fixed disc 151 (e.g., a circular disc) and a plurality of spiral blades 152 arranged circumferentially along the fixed disc 151. See [link to relevant documentation]. Figure 4Relative to the radial direction of the fixed disk 151, the spiral blades 152 are inclined clockwise or counterclockwise by 12–18° (e.g., 15°), thus forming an umbrella shape. In this way, after the particles, charged by the rotating friction pinwheel 12, fall onto the umbrella-shaped spreader 15, the movement path of the particles is effectively extended, further increasing the time and probability of the particles being dispersed and charged. Subsequently, under the action of centrifugal force, they move uniformly outward and are distributed into the inverted cone. Furthermore, the umbrella-shaped spreader 15 allows the particles to be dispersed within the maximum permissible range, improving the uniformity of particle dispersion.

[0051] It should be noted that, in order to prevent the charge of the particles to be tested from becoming disordered, the materials of the spiral blade, the rotating friction pin wheel 12 and the friction medium cylinder 16 are the same. They can be selected according to the triboelectric characteristics of the particles to be tested. The purpose is to make different particles to be tested be charged with different polarities after collision and friction. For example, the materials of the three are PVC.

[0052] In order to enable charged particles of different polarities to be subjected to electric field forces of different magnitudes and directions laterally, thereby producing a large deflection and improving the sorting efficiency of charged particles, the electrostatic sorting unit is exemplarily structured as follows: it includes a housing 18, a power supply 19, multiple collection tanks 20, and multiple pairs of grading electrode plates 17. The end of the housing 18 facing the friction medium cylinder 16 is open, and the opening is located below the friction medium cylinder 16, with a gap of 5-10 cm between it and the outlet of the friction medium cylinder 16. The collection tanks 20 are located at the bottom of the housing 18, and the grading electrode plates 17 are located on the inner wall of the housing 18. One end of the grading electrode plate 17 is electrically connected to the power supply 19, and the other end is grounded. Multiple pairs of grading electrode plates 17 are arranged sequentially in a direction that gradually moves away from the outlet of the friction medium cylinder 16, and the electric field force generated gradually increases. In this way, multiple pairs of graded electrode plates 17 can form multiple adjustable stepped electric fields. Charged particles of different polarities are deflected by the lateral action of electric field forces of different magnitudes and directions, and fall into different collection tanks 20, thereby achieving the separation of charged particles. This solves the problems of insufficient electric field force for deflection of charged particles with smaller mass and excessive deflection and collision with graded electrode plates 17 of particles with larger mass. In addition, unlike the closed electric field, the electrostatic sorting unit of this embodiment is an open sorting field. After being charged, the particles to be sorted enter the high-voltage electrostatic field through the narrow discharge port (i.e., the discharge port of the friction medium cylinder 16). Since it is an open sorting field, the charged particles are not subjected to the force of continuous airflow in the electric field. The airflow only provides an initial velocity to the charged particles. The charged particles fall vertically in the electrostatic sorting zone only by their own gravity. In the horizontal direction, the electric field force provides horizontal acceleration, causing them to deflect and produce different trajectories. They are not disturbed by airflow turbulence, the force situation is simple, and the motion trajectory is relatively uniform and orderly.

[0053] For example, the outer shell 18 is divided into multiple interconnected receiving cavities along the direction of gradually moving away from the discharge port of the friction medium cylinder 16, and a pair of graded electrode plates 17 are provided in each receiving cavity; in each pair of graded electrode plates 17, one graded electrode plate 17 is provided on one side of the receiving cavity and the other graded electrode plate 17 is provided on the other side of the receiving cavity, and the positions of the two graded electrode plates 17 correspond to each other, thereby forming a first-level electric field.

[0054] In practical applications, the number of stages of the tiered electric field can be selected according to the difficulty of sorting charged particles. For example, the number of cavities is 3, and the number of pairs of graded electrode plates 17 is 3, thus forming a three-stage tiered electric field.

[0055] In order to achieve adjustable angle of the tiered electric field, the aforementioned graded electrode plates 17 are inclined and rotatably connected to the outer casing 18. For example, the upper end of the graded electrode plates 17 is rotatably connected to the outer casing 18, and in each pair of graded electrode plates 17, the two graded electrode plates 17 are inclined in opposite directions and symmetrically arranged. In this way, by rotating the graded electrode plates 17, the inclination angle of the graded electrode plates 17 can be adjusted, thereby adjusting the distance between the pair of graded electrode plates 17 and the generated voltage, wherein the voltage range is 25 to 85 kV.

[0056] In order to adjust the arrangement position and method of the collection tank 20 according to the movement and displacement of charged particles, the structure of the collection tank 20 specifically includes a tank body and a partition. The internal space of the tank body is divided into multiple collection tanks 20 by the partition. The partition is slidably and detachably connected to the tank wall. By adjusting the relative position of the partition and the tank body, the position of the corresponding collection tank 20 can be changed, thereby adjusting the arrangement position and method of the collection tank 20 according to the movement and displacement of charged particles.

[0057] The present invention also provides a combined atomization modification electrostatic separation method, employing the above-mentioned combined atomization modification electrostatic separation device, the electrostatic separation method comprising the following steps:

[0058] Step 1: Atomize the surface modifier and then modify the surface of the particles to be selected;

[0059] Step 2: The modified candidate particles are transported into the triboelectric charging unit by the high-speed airflow of the air supply unit, so that the candidate particles are fully charged and become charged particles.

[0060] Step 3: Charged particles enter the electrostatic sorting unit. Charged particles of different polarities are deflected by electric field forces of different magnitudes and directions, and fall into different collection tanks, thus completing the separation of the particles to be sorted.

[0061] Compared with the prior art, the beneficial effects of the combined atomization modification electro-selection method provided by the present invention are basically the same as the beneficial effects of the combined atomization modification electro-selection device provided above, and will not be described in detail here.

[0062] Specifically, the above-mentioned electric separation method includes the following steps:

[0063] Step 1: Set the threshold of the smoke concentration detection controller according to the required surface modifier concentration of the particles to be selected;

[0064] Add the surface modifier to the atomizer, adjust the opening ratio of the voltage regulator plate to zero, turn on the atomizer, and atomize the surface modifier.

[0065] Once the reading of the smoke concentration detection controller on the inner wall of the storage chamber reaches the set reagent concentration, close the discharge regulating device at the discharge end of the feed pipe and the air outlet regulating device at the discharge port of the air supply pipe, turn on the fan, and open the opening rate of the pressure stabilizing plate to the maximum.

[0066] Once the smoke concentration detection controller at the outlet of the air supply duct reaches the set agent concentration threshold, open the air outlet regulating component at the outlet of the air supply duct.

[0067] Adjust the opening ratio of the pressure stabilizing plate according to the flow meter reading to stabilize the pressure drop and airflow in the air supply pipeline. Then set the voltage of each graded electrode plate, start the power supply, and turn on the rotary motor after the voltage stabilizes. After the rotary shaft reaches a stable rotation state, set the frequency of the vibrating feeder's exciter.

[0068] Open the feed adjustment piece at the discharge end of the feed pipe and start the vibrating feeder;

[0069] The selected particles slide down the feed pipe into the air supply pipe. Inside the air supply pipe, they are fully mixed and modified by the stable and uniform airflow and the atomized surface modifier.

[0070] Step 2: The modified candidate particles are carried by the airflow into the triboelectric charging unit. Under the action of the high-speed rotating friction needle wheel, the candidate particle group is fully dispersed and fully charged after colliding and rubbing with the rotating friction needle wheel to obtain charged particles.

[0071] Charged particles fall onto the umbrella-shaped spreader, and under the action of rotating spiral blades, they are evenly spread through the bottom of the inverted cone and fall into the electrostatic sorting unit.

[0072] Step 3: In the gradient electric field, positively charged particles deflect towards the negative plate in the graded electrode plate, and negatively charged particles deflect towards the positive plate in the graded electrode plate. Charged particles with a large mass-to-charge ratio are deflected in advance into the collection groove of the first-stage electrode plate under the action of the electric field force, while charged particles with a small charge-to-mass ratio continue to move downwards and enter the next stage of electric field deflection, separation and collection, finally realizing the separation of particles with different charge-to-mass ratios.

[0073] Example 1

[0074] This embodiment is used for electrostatic separation of -0.5mm coal-series kaolin material. The electrostatic separation method includes the following steps:

[0075] S1. Pour the coal-series kaolin into the storage trough of the vibrating feeder. In this embodiment, kerosene is selected as the surface modifier. Based on the required mass of the sorted coal-series kaolin, inject the surface modifier into the atomizer at a surface modifier-to-particle mass ratio of 5 kg / t. The surface modifier concentration in the air supply pipeline needs to be maintained at 1.8–2.4 kg / m³. 3 The threshold of the concentration detection controller is set according to the concentration of the surface modifier. The atomization rate of the ultrasonic atomizer is adjusted. The ultrasonic atomizer is turned on and the opening rate of the pressure stabilizing plate is adjusted to 0. The kerosene is atomized into small molecules under the action of ultrasonic directional pressure and enters the storage chamber.

[0076] S2. After the reading of the concentration detection controller on the side of the storage chamber reaches the set surface modifier concentration, close the stainless steel insert at the end of the feed pipe and the air supply pipe, turn on the blower, and open the pressure stabilizing plate to the maximum to fill the entire air supply pipe with atomized kerosene; after the reading of the concentration detection controller at the end of the air supply pipe reaches the set surface modifier concentration, open the stainless steel insert at the end of the air supply pipe.

[0077] S3. Adjust the opening ratio of the air receiver, flow meter, and pressure stabilizer plate to stabilize the pressure drop and airflow in the air supply duct. In this embodiment, the air pressure in the air supply duct is maintained at 0.3–0.4 MPa, and the flow rate is 620–700 m³ / h. 3 / h; After all readings stabilize, set the voltage of each electrode plate. The first voltage is set to 28-36kV, the second voltage to 40-48kV, and the third voltage to 52-60kV. The tilt angle of each of the six graded electrode plates is 30°. Start the high-voltage power supply. After the voltage readings stabilize, turn on the rotary motor and set the speed to 400r / min. After the rotating shaft reaches a stable rotation state, set the frequency of the vibrating feeder exciter to 5000Hz.

[0078] S4. Open the stainless steel insert at the end of the feed pipe and start the vibrating feeder switch. The coal-based kaolin slides down the feed pipe into the air supply pipe. In the air supply pipe, it is fully mixed and modified by the stable and uniform airflow and the atomized surface modifier. The modified coal-based kaolin particles enter the triboelectric charging unit under the carrying action of the airflow. Under the action of the high-speed rotating friction needle wheel, the particles to be selected are fully dispersed and fully charged after colliding and rubbing with the rotating friction needle wheel. The charged coal-based kaolin particles fall onto the umbrella spreader. Under the action of the rotating spiral blades, they are evenly spread through the bottom of the funnel and fall into the electrostatic separation unit.

[0079] S5. In the three-stage stepped high-voltage electric field, positively charged clean coal particles deflect towards the negative electrode, while negatively charged kaolinite particles deflect towards the positive electrode. Charged particles with a large charge-to-mass ratio are deflected in advance into the collection trough of the first stage electrode plate under the action of the electric field force, while charged particles with a small charge-to-mass ratio continue to move downwards and enter the next stage of electric field deflection, separation and collection. Electroneutral particles move vertically downwards and fall into the collection trough in the middle of the bottom, realizing the separation of particles with different charge-to-mass ratios, which can effectively remove carbon impurities from coal-series kaolin.

[0080] Example 2

[0081] This embodiment is used for electrostatic separation of -0.25mm fly ash materials. The electrostatic separation method includes the following steps:

[0082] S1. Pour the fly ash into the storage trough of the vibrating feeder. In this embodiment, citric acid is selected as the surface modifier. Based on the required mass of fly ash to be sorted, inject the surface modifier into the atomizer at a ratio of 7 kg / t of surface modifier to particle mass. The concentration of the surface modifier in the air supply duct should be maintained at 4.5–4.8 kg / m³. 3 The threshold of the concentration detection controller is set according to the concentration of the surface modifier. The atomization rate of the ultrasonic atomizer is adjusted. The ultrasonic atomizer is turned on and the opening rate of the pressure plate is adjusted to 0. Citric acid is atomized into small molecules under the action of ultrasonic directional pressure and enters the storage chamber.

[0083] S2. After the concentration detection controller on the side of the storage chamber reaches the set surface modifier concentration, close the stainless steel insert at the end of the feed pipe and the air supply pipe, turn on the fan, and open the pressure stabilizing plate to the maximum to fill the entire air supply pipe with atomized citric acid; after the concentration detection controller at the end of the air supply pipe reaches the set surface modifier concentration, open the stainless steel insert at the end of the air supply pipe.

[0084] S3. Adjust the opening ratio of the air receiver, flow meter, and pressure stabilizer plate to stabilize the pressure drop and airflow in the air supply duct. In this embodiment, the air pressure in the air supply duct is maintained at 0.4–0.5 MPa, and the flow rate is 560–600 m³ / h. 3 / h; After all readings stabilize, set the voltage of each electrode plate. The first voltage is set to 38-44kV, the second voltage to 50-56kV, and the third voltage to 62-68kV. The tilt angle of each of the six graded electrode plates is 15°. Start the high-voltage power supply. After the voltage readings stabilize, turn on the rotary motor and set the speed to 550r / min. After the rotating shaft reaches a stable rotation state, set the frequency of the vibrating feeder exciter to 4600Hz.

[0085] S4. Open the stainless steel insert at the end of the feed pipe and start the vibrating feeder switch. The fly ash slides down the feed pipe into the air supply pipe. In the air supply pipe, it is fully mixed and modified by the stable and uniform airflow and the atomized surface modifier. The modified fly ash particles enter the triboelectric charging unit under the carrying action of the airflow. Under the action of the high-speed rotating friction needle wheel, the particles to be selected are fully dispersed and fully charged after colliding and rubbing with the rotating friction needle wheel. The charged fly ash particles fall onto the umbrella spreader. Under the action of the rotating spiral blades, they are evenly spread through the bottom of the funnel and fall into the electrostatic sorting unit.

[0086] S5. In the three-stage stepped electric field, positively charged carbon particles deflect towards the negative electrode, and negatively charged ash particles deflect towards the positive electrode. Charged particles with a large charge-to-mass ratio are deflected in advance into the collection trough of the first stage electrode plate under the action of the electric field force, while charged particles with a small charge-to-mass ratio continue to move downwards and enter the next stage of electric field deflection, separation and collection. The electrically neutral particles move vertically downwards and fall into the collection trough in the middle of the bottom, realizing the separation of particles with different charge-to-mass ratios, which can effectively remove carbon impurities from fly ash.

[0087] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A combined atomization-modified electrostatic separator, characterized in that, The system includes an air supply unit, an air supply duct, a feeding unit, a modified atomizing unit, a triboelectric charging unit, and an electrostatic sorting unit; these units are connected sequentially. The air supply unit and the air supply duct are connected, and the outlet of the feeding unit and the air outlet of the modified atomizing unit are both connected to the air supply duct. The air supply unit provides airflow from the air supply unit to the air supply duct, the feeding unit provides the particles to be selected, and the modified atomizing unit provides atomized surface modifiers. The particles to be selected and the atomized surface modifiers are mixed in the air supply duct. The triboelectric charging unit includes a friction medium cylinder, a rotary motor, a rotary shaft, a rotary friction pinwheel, and a canopy spreader. The inlet of the friction medium cylinder is connected to the outlet of the air supply duct, and the outlet of the friction medium cylinder is connected to the electrostatic sorting unit. The feed inlet of the unit is connected, and the rotating shaft, rotating friction pinwheel, and umbrella surface spreader are located inside the friction medium cylinder. One end of the rotating shaft is fixedly connected to the rotating motor, and the other end passes through the rotating friction pinwheel and is fixedly connected to the umbrella surface spreader. The rotating motor drives the rotating friction pinwheel and the spreader to rotate around the rotating shaft through the rotating shaft. The rotating friction pinwheel includes multiple charged layers arranged axially along the rotating shaft. There is a gap between adjacent charged layers. Each charged layer includes multiple needles arranged radially around the rotating shaft. There is a gap between each needle. There is a gap between the tip of the needle and the inner wall of the friction medium cylinder. The umbrella surface spreader includes a fixed disk and multiple spiral blades arranged circumferentially along the fixed disk. The spiral blades are inclined clockwise or counterclockwise relative to the radial direction of the fixed disk. The electrostatic sorting unit includes a housing, a power supply, multiple collection tanks, and multiple pairs of grading electrode plates. The end of the housing facing the friction medium cylinder is open, located below the friction medium cylinder, with a gap between it and the outlet of the friction medium cylinder. The collection tanks are located at the bottom of the housing, and the grading electrode plates are located on the inner wall of the housing. One end of each grading electrode plate is electrically connected to the power supply, and the other end is grounded. The multiple pairs of grading electrode plates are arranged sequentially along the direction gradually moving away from the outlet of the friction medium cylinder, and the electric field force generated gradually increases. The housing is divided into multiple interconnected receiving cavities along the direction gradually moving away from the outlet of the friction medium cylinder. Each receiving cavity contains a pair of grading electrode plates. In each pair of grading electrode plates, one grading electrode plate is located on one side of the receiving cavity, and the other grading electrode plate is located on the other side of the receiving cavity, with the positions of the two grading electrode plates corresponding to each other, forming a first-level electric field. The grading electrode plates are inclined and rotatably connected to the housing, and in each pair of grading electrode plates, the two grading electrode plates are inclined in opposite directions and symmetrically arranged. The collection tank includes a tank body and a partition. The internal space of the tank body is divided into multiple collection tanks by the partition. The partition slides and is detachably connected to the tank wall. By adjusting the relative position of the partition and the tank body, the position of the corresponding collection tank can be changed. The electrostatic separator also includes a concentration detection controller for detecting the concentration of the surface modifier; there are two concentration detection controllers, one of which is located on the inner wall of the storage chamber and the other is located at the air outlet of the air supply duct; the concentration detection controller detects the real-time surface modifier concentration data in real time and determines whether the real-time surface modifier concentration data has reached a threshold. If it has not reached the threshold, the real-time surface modifier concentration data is adjusted by the atomizer until the real-time surface modifier concentration data reaches the threshold.

2. The electrostatic separator with combined atomization modification according to claim 1, characterized in that, The air supply unit includes a fan and an air receiver. The air outlet of the fan is connected to the air inlet of the air receiver, and the air outlet of the air receiver is connected to the air inlet of the air supply duct.

3. The electrostatic separator with combined atomization modification according to claim 2, characterized in that, A flow meter is installed on the air supply duct; The flow meter detects the real-time air supply flow data in real time and determines whether the real-time air supply flow data is within the threshold range. If not, the real-time air supply flow is adjusted by the air manifold until the real-time air supply flow is within the threshold range.

4. The electrostatic separator with combined atomization modification according to claim 1, characterized in that, The feeding unit includes a storage tank and a vibrator. The outlet of the storage tank is connected to the air supply pipe, and the vibrator is used to drive the storage tank to reciprocate.

5. The electrostatic separator with combined atomization modification according to claim 4, characterized in that, The storage tank is located above the air supply duct, and the outlet of the storage tank is located at the bottom of the storage tank. The outlet of the storage tank is connected to the air supply duct through a feeding pipe, which is inclined.

6. The electrostatic separator with combined atomization modification according to claim 1, characterized in that, The modified atomizing unit includes an atomizer and a storage chamber. The storage chamber is used to store the atomized surface modifier. The outlet of the atomizer is connected to the inlet of the storage chamber. The air inlet and outlet of the storage chamber are both connected to the air supply duct. Along the air supply direction, the flow meter, the outlet of the feed pipe, the inlet of the storage bin, and the outlet of the storage bin are installed in sequence.

7. The electrostatic separator with combined atomization modification according to claim 6, characterized in that, The air inlet and outlet of the storage chamber are both connected to the air supply duct via connecting pipes, and a pressure stabilizing plate is provided on the connecting pipes.

8. The electrostatic separator with combined atomization modification according to claim 7, characterized in that, The voltage regulator plate includes a plate body, on which multiple through holes are formed.

9. A combined atomization-modified electrostatic separation method, characterized in that, Electrostatic separation is performed using the combined atomization-modified electrostatic separation device as described in any one of claims 1 to 8.

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