Jet mill for reducing electrostatic charge of powder

Abstract

The utility model discloses a kind of airflow pulverizers reducing powder electrostatic, it is related to airflow pulverizer technical field, including rack, the top of the rack is provided with pulverizing cavity, the top of the pulverizing cavity is provided with dispersion component for dispersing material, the bottom of the steam injection pipe is equipped with multiple evenly distributed injection ports, the controller is electrically connected with humidity sensor and steam generator respectively.The utility model is equipped with humidifying assembly with humidity sensor and controller, realizes the accurate control of airflow humidity, uses moderate water vapor to reduce the friction electrification effect between powder particles and between powder and equipment components, the targeted humidity regulation and antistatic coating, conductive structure synergistic effect, form the double protection of "reduce static generation+ promptly guide and remove static electricity", significantly improve the processing capacity of equipment to electrostatic sensitive powder, ensure the dispersibility and production safety of powder after crushing.

Description

Technical Field

[0001] This utility model relates to the field of airflow pulverizer technology, specifically to an airflow pulverizer that reduces the static electricity of powder. Background Technology

[0002] Air jet mills are widely used in chemical, pharmaceutical, food, and materials industries to pulverize materials to the required particle size. Their working principle is to use high-speed airflow (usually compressed air or superheated steam) to cause material particles to impact, collide, and rub against each other, thereby achieving the purpose of pulverization.

[0003] However, during air jet milling, the high-speed friction and collision between the powder and internal components of the equipment (such as pipes, milling chamber walls, classifiers, etc.) and between the powder particles inevitably generate static electricity. The accumulation of static electricity can cause many serious problems in production. On the one hand, static electricity can cause powder particles to adsorb and agglomerate, affecting the flowability and dispersibility of the powder, resulting in a wider particle size distribution of the product, which cannot meet the strict requirements of the production process for powder particle size. On the other hand, static electricity accumulation to a certain extent may trigger electrostatic discharge, generating electric sparks. For some flammable and explosive powders, such as flour, coal powder, and chemical raw material powder, electrostatic discharge may cause dust explosions, resulting in serious casualties and property damage.

[0004] For example, CN208288190U discloses an airflow pulverizer, including a machine body, stirring blades, a discharge port, a frame, an airflow chamber, and a connecting rod. A motor is mounted on the upper end of the machine body, and a drive shaft is connected to the motor. The drive shaft passes through the wall of the machine body, and a stirring shaft is connected to the end of the drive shaft. The stirring blades are mounted on the stirring shaft. A feeder is connected to the feed pipe. The airflow chamber is located on the left and right sides of the lower end of the machine body, and a baffle is mounted on the airflow chamber. A spray nozzle is mounted on the baffle. The connecting rod is located on the inner surface of the machine body and connects... The connecting rod is equipped with a rotator, and a crushing roller is connected to the rotator. The crushing roller is equipped with a crushing blade. The mechanical friction between the stirring blade and the material in this patent will generate a large amount of static electricity. However, the equipment is not equipped with a function to reduce the static electricity of the powder. The static electricity is easy to accumulate inside the machine. The strong static electricity generated by mechanical friction will not only cause the crushed powder particles to attract and agglomerate with each other, and the fine powder that should be micron-sized will agglomerate into larger particles, causing the particle size distribution of the product to deviate from the process requirements, but also cause the electric spark generated by electrostatic discharge to directly ignite the powder suspended in the air, causing an explosion accident.

[0005] Therefore, it is necessary to invent an airflow pulverizer that reduces the static electricity of powder to solve the above problems. Utility Model Content

[0006] The purpose of this invention is to provide an airflow pulverizer that reduces static electricity in powders, thus solving the problem of not being able to reduce static electricity in powders.

[0007] To achieve the above objectives, this utility model provides the following technical solution: an airflow pulverizer for reducing static electricity in powder, comprising a frame, a pulverizing chamber disposed directly above the frame, a dispersion component for dispersing materials disposed above the pulverizing chamber, an air compressor disposed on one side above the frame, an air inlet pipe connected to the air compressor's outlet end, the end of the air inlet pipe extending into the interior of the pulverizing chamber, an antistatic coating on the inner wall of the pulverizing chamber, a humidification component for regulating airflow humidity connected in series on the air inlet pipe, the humidification component comprising a humidification chamber, a humidity sensor disposed on one side of the inner wall of the humidification chamber, a controller disposed at the top of the outer side of the humidification chamber, a steam generator disposed on one side of the outer side of the humidification chamber, a steam delivery pipe connected to the steam generator's outlet end extending into the interior of the humidification chamber, a steam injection pipe disposed at the top of the interior of the humidification chamber, the steam injection pipe's inlet end communicating with the steam delivery pipe's outlet end, a plurality of evenly distributed injection nozzles disposed at the bottom of the steam injection pipe, and the controller electrically connected to the humidity sensor and the steam generator respectively.

[0008] Preferably, the dispersing component includes a dispersing box, the top of which is provided with a feeding hopper, and the bottom of which is provided with a discharge port, which is connected to the feeding port of the crushing chamber.

[0009] Preferably, the grinding chamber is provided with a stirring shaft inside, and the outer circumferential surface of the stirring shaft is provided with multiple dispersing blades. The dispersing blades are made of stainless steel, and the dispersing blades are fixedly connected to the stirring shaft by conductive bolts.

[0010] Preferably, a servo motor is provided on one side of the lower part of the frame, a gear one is provided at the output end of the servo motor, a gear two is provided directly above the gear one and installed at one end of the stirring shaft, and a toothed belt is tensioned between the gear one and the gear two.

[0011] Preferably, one end of the stirring shaft penetrates the side wall of the grinding chamber and extends to the outside, and a conductive sealing ring is provided at the penetration point between the stirring shaft and the grinding chamber, the conductive sealing ring being electrically connected to the inner wall of the grinding chamber.

[0012] Preferably, the inner wall of the crushing chamber is provided with an annular tube, the air inlet end of the annular tube is connected to the air outlet end of the air inlet pipe, and multiple nozzles are provided below the annular tube, and the multiple nozzles are evenly arranged along the circumference of the annular tube.

[0013] Preferably, the nozzle is made of ceramic material, and the outlet end of the nozzle is inclined towards the central axis of the crushing chamber at an angle of 30-45°.

[0014] Preferably, a control panel is provided on the front side above the frame, and the control panel is electrically connected to the servo motor, the air compressor and the controller respectively.

[0015] The technical effects and advantages provided by this utility model in the above technical solution are as follows:

[0016] 1. This utility model constructs a complete static electricity discharge path by coating the inner wall of the grinding chamber with an antistatic coating, combining the conductive bolt connection between the dispersing blades and the stirring shaft, the conductive sealing ring, and the potential grounding structure. The antistatic coating can directly discharge the static electricity generated by the friction between the powder and the chamber wall. After the stainless steel dispersing blades and the stirring shaft are connected by conductive bolts, the static electricity generated by mechanical stirring can be transmitted to the grinding chamber and the frame through the stirring shaft and the conductive sealing ring, thus achieving effective discharge of static electricity. This reduces the accumulation of static electricity from the source, reduces the probability of powder agglomeration due to static electricity adsorption, and avoids the safety risks caused by electrostatic discharge.

[0017] 2. This utility model achieves precise control of airflow humidity by setting up a humidification component with a humidity sensor and controller. When the humidity sensor detects that the airflow humidity in the air inlet pipe is lower than the process threshold, the controller automatically starts the steam generator and injects steam evenly into the airflow through the steam injection pipe to increase the humidity. The moderate water vapor reduces the frictional static electricity effect between powder particles and between the powder and equipment components. This targeted humidity regulation, together with the antistatic coating and conductive structure, forms a dual protection of "reducing static electricity generation + timely dissipation of static electricity", which significantly improves the equipment's ability to handle static-sensitive powders and ensures the dispersibility and production safety of the powder after crushing. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0019] Figure 2 This is a three-dimensional cross-sectional structural diagram of the dispersion box of this utility model;

[0020] Figure 3 This is a three-dimensional structural diagram of the air compressor of this utility model;

[0021] Figure 4 This is a three-dimensional cross-sectional view of the crushing chamber of this utility model;

[0022] Figure 5 This is a three-dimensional cross-sectional structural diagram of the humidifier box of this utility model;

[0023] Figure 6 This is a schematic diagram of the humidification process structure of the humidification component of this utility model.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Frame; 2. Grinding chamber; 3. Dispersion assembly; 301. Dispersion box; 302. Feed hopper; 303. Discharge port; 304. Stirring shaft; 305. Dispersion blades; 4. Servo motor; 5. Gear 1; 6. Gear 2; 7. Toothed belt; 8. Air compressor; 9. Air inlet pipe; 10. Control panel; 11. Circular pipe; 12. Nozzle; 13. Antistatic coating; 14. Humidification assembly; 1401. Humidification box; 1402. Humidity sensor; 1403. Controller; 1405. Steam generator; 1406. Steam supply pipe; 1407. Steam injection pipe. Detailed Implementation

[0026] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0027] This utility model provides, for example Figure 1-6 The airflow pulverizer for reducing static electricity in powders, as shown, includes a frame 1. A pulverizing chamber 2 is disposed directly above the frame 1. A dispersion component 3 for dispersing materials is disposed above the pulverizing chamber 2. An air compressor 8 is disposed on one side above the frame 1. An air inlet pipe 9 is connected to the air outlet of the air compressor 8. The end of the air inlet pipe 9 extends into the interior of the pulverizing chamber 2. The inner wall of the pulverizing chamber 2 is coated with an antistatic coating 13. A humidification component 14 for regulating airflow humidity is connected in series on the air inlet pipe 9. The humidification component 14 includes a humidification box 1401. A humidity sensor 1402 is disposed on one side of the inner wall of the humidification box 1401. A controller 1403 is provided on the top of the humidifier box 1401. A steam generator 1405 is provided on one side of the humidifier box 1401. The steam outlet of the steam generator 1405 is connected to a steam supply pipe 1406, and its end extends into the humidifier box 1401. A steam injection pipe 1407 is provided on the top of the humidifier box 1401. The steam inlet of the steam injection pipe 1407 is connected to the steam outlet of the steam supply pipe 1406. The bottom of the steam injection pipe 1407 is provided with multiple evenly distributed injection nozzles. The controller 1403 is electrically connected to the humidity sensor 1402 and the steam generator 1405 respectively.

[0028] In this embodiment, the conductive coating 13 discharges the static electricity generated by the friction between the powder and the inner wall of the grinding chamber 2, avoiding charge accumulation that could lead to agglomeration or discharge. Furthermore, the resistivity of the powder is reduced by humidity regulation. For every 10% increase in humidity, the resistivity decreases by approximately one order of magnitude, reducing static electricity generation. At the same time, it prevents excessive drying from increasing the brittleness of the powder, thus optimizing the grinding effect. In addition, the humidity sensor 1402 is linked with the controller 1403 to achieve dynamic adjustment of the steam injection volume, ensuring that the airflow humidity remains stable within a safe range.

[0029] The dispersion assembly 3 includes a dispersion box 301, a feed hopper 302 at the top of the dispersion box 301, and a discharge port 303 at the bottom of the dispersion box 301. The discharge port 303 is connected to the feed port of the crushing chamber 2. The crushing chamber 2 is equipped with a stirring shaft 304. The outer circumference of the stirring shaft 304 is equipped with multiple dispersion blades 305. The dispersion blades 305 are made of stainless steel. The dispersion blades 305 are fixedly connected to the stirring shaft 304 by conductive bolts. A servo motor 4 is provided on one side of the lower part of the frame 1. A gear 5 is provided at the output end of the servo motor 4. A gear 6 is provided directly above the gear 5 and installed at one end of the stirring shaft 304. A toothed belt 7 is tensioned between the gear 5 and the gear 6.

[0030] In this embodiment, the high-speed rotation of the dispersing blade 305 breaks up agglomerated materials, thereby improving the crushing efficiency. The stainless steel material and conductive bolt design prevent the dispersing blade 305 from being independently charged, thus preventing the accumulation of local static electricity. In addition, the conductive sealing ring eliminates the insulation gap between the stirring shaft 304 and the crushing chamber 2, ensuring that static electricity is conducted to the inner wall of the crushing chamber 2 through the shaft and discharged through the anti-static coating.

[0031] One end of the stirring shaft 304 passes through the side wall of the grinding chamber 2 and extends to the outside. A conductive sealing ring is provided at the penetration point between the stirring shaft 304 and the grinding chamber 2. The conductive sealing ring is electrically connected to the inner wall of the grinding chamber 2. An annular tube 11 is provided on the inner wall of the grinding chamber 2. The air inlet end of the annular tube 11 is connected to the air outlet end of the air inlet pipe 9. Multiple nozzles 12 are provided below the annular tube 11. The multiple nozzles 12 are evenly arranged around the circumference of the annular tube 11. The nozzles 12 are made of ceramic material. The outlet end of the nozzle 12 is inclined towards the central axis of the grinding chamber 2 at an angle of 30-45°. A control panel 10 is provided on the front side above the frame 1. The control panel 10 is electrically connected to the servo motor 4, the air compressor 8 and the controller 1403 respectively.

[0032] In this embodiment, the inclined Laval nozzle 12 design causes the airflow to form a vortex, which prolongs the residence time of the powder in the grinding chamber 2 and effectively improves the uniformity of grinding.

[0033] Working principle of this utility model:

[0034] Refer to the instruction manual appendix Figure 1-4When using this utility model, first, press the power switch on the control panel 10 to start the equipment control system, slowly pour the prepared powder material to be crushed into the feed hopper 302, and the material enters the crushing chamber 2 through the discharge port 303. The material entering the crushing chamber 2 is first subjected to the action of the high-speed rotating dispersing blades 305, and the agglomerated material is broken up, so that the material is evenly dispersed and the subsequent crushing efficiency is improved. The material crushed by the dispersing blades 305 enters the crushing chamber 2. The dispersed material is subjected to the impact, shearing and collision of the high-speed airflow sprayed from the nozzle 12 in the crushing chamber 2, and the crushing is achieved. Then, start the air compressor 8, and the air compressor 8 delivers compressed air into the crushing chamber 2 through the air inlet pipe 9.

[0035] Refer to the instruction manual appendix Figure 5-6 When using this invention, before the airflow enters the grinding chamber 2, it can first enter the humidification box 1401 and the humidity is detected by the humidity sensor 1402. The humidity sensor 1402 monitors the humidity in the humidification box 1401 in real time and feeds the data back to the controller 1403, which determines whether to turn the humidification component 14 on or off. The controller 1403 controls the steam generator 1405 to generate an appropriate amount of steam according to the set target humidity. The steam is delivered to the steam injection pipe 1407 through the steam delivery pipe 1406 and sprayed into the humidification box 1401 from multiple evenly distributed injection ports at the bottom of the steam injection pipe 1407. This adjusts the humidity of the airflow entering the grinding chamber 2, ensuring that the humidity of the airflow entering the grinding chamber 2 is stable within the optimal range. The appropriate humidity can not only reduce the static electricity generated by the powder during the grinding process and reduce the adhesion and agglomeration of materials caused by electrostatic adsorption, but also improve the flowability and dispersibility of the powder, further improving the grinding effect.

[0036] The air compressor 8 and steam generator 1405 mentioned in this application are both existing products and can be easily purchased on the market. The air compressor 8 comes in various types, such as piston type, screw type, centrifugal type, etc., each of which has its applicable scenarios and characteristics. We can select the appropriate air compressor 8 model according to the specific needs of the project, such as the required compressed air pressure, flow rate, purity and other parameters. The steam generator 1405 also has different heating methods, such as electric heating, gas heating, oil heating, etc. We can comprehensively consider the project's energy supply, cost budget, environmental protection requirements and other factors to determine the most suitable type of steam generator 1405. Since these products are all existing, they are not described in detail in this application.

[0037] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0038] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An airflow pulverizer for reducing static electricity in powders, comprising a frame (1), characterized in that: A grinding chamber (2) is provided directly above the frame (1). A dispersion component (3) for dispersing materials is provided above the grinding chamber (2). An air compressor (8) is provided on one side above the frame (1). An air inlet pipe (9) is connected to the air outlet of the air compressor (8). The end of the air inlet pipe (9) extends into the interior of the grinding chamber (2). The inner wall of the grinding chamber (2) is coated with an antistatic coating (13). A humidifying component (14) for adjusting the humidity of the airflow is connected in series on the air inlet pipe (9). The humidifying component (14) includes a humidifying box (1401). A humidity sensor (1402) is provided on one side of the inner wall of the humidifying box (1401). The top of the humidifier box (1401) is equipped with a controller (1403). A steam generator (1405) is provided on one side of the humidifier box (1401). The steam outlet of the steam generator (1405) is connected to a steam supply pipe (1406) and its end extends into the humidifier box (1401). The top of the humidifier box (1401) is equipped with a steam injection pipe (1407). The steam inlet of the steam injection pipe (1407) is connected to the steam outlet of the steam supply pipe (1406). The bottom of the steam injection pipe (1407) is provided with multiple evenly distributed injection ports. The controller (1403) is electrically connected to the humidity sensor (1402) and the steam generator (1405) respectively.

2. The airflow pulverizer for reducing static electricity in powders according to claim 1, characterized in that: The dispersion component (3) includes a dispersion box (301), the top of the dispersion box (301) is provided with a feed hopper (302), the bottom of the dispersion box (301) is provided with a discharge port (303), and the discharge port (303) is connected to the feed port of the crushing chamber (2).

3. The airflow pulverizer for reducing static electricity in powders according to claim 2, characterized in that: The grinding chamber (2) is equipped with a stirring shaft (304) inside. The outer circumferential surface of the stirring shaft (304) is provided with multiple dispersing blades (305). The dispersing blades (305) are made of stainless steel. The dispersing blades (305) are fixedly connected to the stirring shaft (304) by conductive bolts.

4. The airflow pulverizer for reducing static electricity in powders according to claim 1, characterized in that: A servo motor (4) is provided on one side below the frame (1). A gear 1 (5) is provided at the output end of the servo motor (4). A gear 2 (6) is provided directly above the gear 1 (5) and installed at one end of the stirring shaft (304). A toothed belt (7) is tensioned between the gear 1 (5) and the gear 2 (6).

5. The airflow pulverizer for reducing static electricity in powders according to claim 4, characterized in that: One end of the stirring shaft (304) penetrates the side wall of the grinding chamber (2) and extends to the outside. A conductive sealing ring is provided at the penetration point between the stirring shaft (304) and the grinding chamber (2). The conductive sealing ring is electrically connected to the inner wall of the grinding chamber (2).

6. The airflow pulverizer for reducing static electricity in powders according to claim 5, characterized in that: The inner wall of the crushing chamber (2) is provided with an annular tube (11), the air inlet end of the annular tube (11) is connected to the air outlet end of the air inlet pipe (9), and a plurality of nozzles (12) are provided below the annular tube (11), and the plurality of nozzles (12) are evenly arranged along the circumference of the annular tube (11).

7. The airflow pulverizer for reducing static electricity in powders according to claim 6, characterized in that: The nozzle (12) is made of ceramic material, and the outlet end of the nozzle (12) is inclined towards the central axis of the crushing chamber (2) at an angle of 30-45°.

8. The airflow pulverizer for reducing static electricity in powders according to claim 1, characterized in that: The front side of the frame (1) is provided with a control panel (10), and the control panel (10) is electrically connected to the servo motor (4), the air compressor (8) and the controller (1403).

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