A system for preventing agglomeration of ultrafine powders

Abstract

The application discloses a system for preventing agglomeration of superfine powder, which comprises a charge chamber arranged in a gas-phase dynamic mill, a first ion generator for conveying first ions into the charge chamber to form an electric environment of the first ions in the charge chamber, and a second ion generator for conveying second ions with opposite electric properties to the first ions into a falling area through which the large particles fall. When the powder passes through the charge chamber, the powder particles carry the first ions and have the same electric properties, so that the agglomeration of the powder particles can be avoided according to the principle of repulsion between same properties. The first ions on the falling large particles are neutralized by the second ions, so that the large particles become uncharged particles and directly fall into a supersonic airflow input area for further crushing. The system can prevent the superfine particles from being too close to each other to generate force and adsorption force by using the repulsive force of the same electric charges, so that the dispersion degree of the superfine particles is improved and the agglomeration of the superfine particles is prevented.

Description

Technical Field

[0001] This application relates to the field of automation control technology, and in particular to a system for preventing the agglomeration of ultrafine powders. Background Technology

[0002] Gas-phase dynamic mills are used to pulverize materials. A supersonic airflow is generated through Laval nozzles, causing the material to collide and shear at high speed. The pulverized material enters a forced vortex classifier at the top of the mill for classification, ensuring no dead zones. The classified ash is collected by a bag filter with the airflow and discharged from the dust collector's hopper to the finished product bin. Coarse materials fall into the pulverizing zone for further grinding, while extremely difficult-to-pulverize impurities are discharged from the slag discharge port at the bottom of the mill. When gas-phase dynamic mills are used for the preparation of ultrafine powders, the extremely small particle size of ultrafine powders makes them prone to agglomeration, affecting the particle size index of the ultrafine powders prepared by the gas-phase dynamic mill and subsequent separation and conveying processes. Summary of the Invention

[0003] The technical problem to be solved by this application is that existing gas phase power mills are prone to agglomeration when pulverizing ultrafine powders. To this end, this application proposes a system to prevent agglomeration of ultrafine powders.

[0004] To address the aforementioned technical problems, this application provides the following technical solution:

[0005] This application provides a system for preventing the agglomeration of ultrafine powders, comprising:

[0006] The charge chamber is located in the gas phase power mill, above the supersonic airflow input position;

[0007] A first ion generator outputs first ions to the charge chamber;

[0008] The first charge controller receives the powder charge output by the first charge measuring device and controls the power of the first ion generator according to the difference between the powder charge and the first preset charge to control the amount of first ions entering the charge chamber.

[0009] A second ion generator outputs second ions to the landing zone between the charge chamber and the gas-phase power mill, the second ions having the opposite charge to the first ions;

[0010] The second charge measuring device is located at the bottom opening of the landing zone and is used to measure the charge of the powder falling into the supersonic airflow input area from the landing zone.

[0011] The second charge controller receives the powder charge output by the second charge measuring device and controls the power of the second ion generator based on the difference between the powder charge and the second preset charge to control the amount of second ions entering the landing zone.

[0012] Some of the systems described in the solutions for preventing the agglomeration of ultrafine powders also include:

[0013] The third ion generator outputs the first electro-ions to the discharge pipe of the gas phase power mill.

[0014] A third charge measuring device is installed in the discharge pipe to measure the charge of the powder in the discharge pipe;

[0015] The third charge controller receives the powder charge output by the third charge measuring device and controls the power of the third ion generator based on the difference between the powder charge and the third preset charge to control the amount of first ions entering the discharge pipe.

[0016] Some of the systems described in the proposals for preventing the agglomeration of ultrafine powders:

[0017] The second preset charge level is zero;

[0018] The first preset charge and the third preset charge are charge thresholds that cause the ultrafine powders to repel each other.

[0019] Some of the systems described in the solutions for preventing the agglomeration of ultrafine powders also include:

[0020] Fan;

[0021] The first ion chamber has one inlet connected to the outlet of the fan and the other inlet connected to the outlet of the first ion generator. The first ion chamber mixes the airflow output by the fan with the first ions generated by the first ion generator to form a first ion wind, which is then transported to the charge chamber.

[0022] The second ion chamber has one inlet connected to the outlet of the fan and the other inlet connected to the outlet of the second ion generator. The second ion chamber mixes the airflow output by the fan with the second ions generated by the second ion generator to form a second ion wind, which is then transported to the landing area.

[0023] Some of the systems described in the solutions for preventing the agglomeration of ultrafine powders also include:

[0024] The third ion chamber has one inlet connected to the outlet of the blower and the other inlet connected to the outlet of the third ion generator. The third ion chamber mixes the airflow output by the blower with the first ions generated by the third ion generator to form a third ion airflow, which is then transported to the discharge pipe.

[0025] Some of the systems described in the solutions for preventing the agglomeration of ultrafine powders also include:

[0026] A first pressure sensor is disposed in the charge chamber and is used to detect the pressure value inside the charge chamber;

[0027] A second pressure sensor is installed in the landing zone to detect the pressure value in the landing zone;

[0028] A third pressure sensor is installed in the discharge pipe to detect the pressure value of the discharge pipe;

[0029] The controller of the blower receives pressure values ​​detected by the first pressure sensor, the second pressure sensor, and the third pressure sensor, and controls the power of the blower according to the pressure value detection results of each pressure sensor to ensure that the first ion wind enters the charge chamber, the second ion wind enters the falling zone, and the third ion wind enters the discharge pipe.

[0030] Some of the systems described in the proposals for preventing the agglomeration of ultrafine powders:

[0031] Multiple first ion inlets are uniformly arranged on the cylindrical body of the charge chamber, and the multiple first ion inlets are uniformly distributed on the cylindrical body.

[0032] In some solutions, the system for preventing the agglomeration of ultrafine powders has multiple first ion inlets arranged in three rows; wherein: the first ion inlets in the middle row are arranged horizontally, the first ion inlets in the upper row are arranged inclined downwards, and the first ion inlets in the lower row are arranged inclined upwards.

[0033] In some solutions, the system for preventing the agglomeration of ultrafine powders has multiple second ion inlets at the top of the landing zone, and these multiple second ion inlets are inclined downwards.

[0034] In some solutions, the system for preventing agglomeration of ultrafine powders has multiple third ion inlets arranged along the circumference of the outlet pipe and along the extension direction of the pipe, and the third ion inlets are inclined along the discharge direction.

[0035] The technical solution of this application has the following technical advantages over the prior art:

[0036] The system for preventing the agglomeration of ultrafine powders provided in this application utilizes a charge chamber within a gas-phase power mill. A first ion generator introduces first ions into the charge chamber, creating an electrically charged environment. When powder passes through the charge chamber, all powder particles carry the first ions, resulting in a uniform charge. Based on the principle of like charges repelling, this prevents particle agglomeration. As larger particles descend through the landing zone, a second ion generator introduces second ions with the opposite charge to the first ions. This neutralizes the first and second ions on the descending large particles, creating uncharged particles that directly descend into the supersonic airflow input area for further collision and breakup. This solution utilizes the repulsive force of like charges to prevent interaction and adsorption forces between ultrafine particles due to close proximity, improving particle dispersion and preventing agglomeration. Attached Figure Description

[0037] The preferred embodiments of this application will be described in detail below with reference to the accompanying drawings, which will help to understand the purpose and advantages of this application, wherein:

[0038] Figure 1 This is a schematic diagram of the structure of a system for preventing the agglomeration of ultrafine powders according to an embodiment of this application;

[0039] Figure 2 This is a schematic diagram of the structure of the system for preventing the agglomeration of ultrafine powder described in another embodiment of this application, in conjunction with a gas-phase power mill. Detailed Implementation

[0040] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0043] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0044] This application provides a system for preventing the agglomeration of ultrafine powders, such as... Figure 1 and Figure 2 As shown, the system includes a charge chamber disposed in the gas phase power mill 211, which is located above the supersonic airflow input position. A first ion generator 204 outputs first ions to the charge chamber; a first charge measuring device A1 is located at the outlet of the charge chamber and is used to measure the charge of the powder output from the charge chamber; a first charge controller 205 receives the charge of the powder output by the first charge measuring device A1 and controls the power of the first ion generator 201 according to the difference between the powder charge and a first preset charge to control the amount of first ions entering the charge chamber; a second ion generator 203 outputs second ions to the landing zone between the charge chamber and the gas phase power mill, the second ions having the opposite charge to the first ions; a second charge measuring device A2 is located at the bottom of the landing zone and is used to measure the charge of the powder falling into the supersonic airflow input area; a second charge controller 202 receives the charge of the powder output by the second charge measuring device A2 and controls the power of the second ion generator 203 according to the difference between the powder charge and a second preset charge to control the amount of second ions entering the landing zone.

[0045] Specifically, the charge chamber is a cylindrical metal structure with flared, trumpet-shaped openings at both the upper and lower ends. The charge chamber is fixed to the outer cylinder of the gas-phase power mill via a fixed arm. The charge chamber and the outer cylinder of the gas-phase power mill are arranged coaxially. The area from the lower end of the charge chamber to the bottom of the gas-phase power mill is the collision zone or supersonic airflow input zone, and the annular space formed between the charge chamber and the outer cylinder of the gas-phase power mill is the landing zone. The diameter of the upper opening of the charge chamber is smaller than the diameter of the classifier impeller, and the distance from the upper surface of the charge chamber to the classifier impeller is half the radius of the classifier impeller. The distance from the lower surface of the charge chamber to the supersonic airflow nozzle is the diameter of the outer cylinder of the gas-phase power mill. The diameter of the lower opening of the charge chamber is smaller than the diameter of the upper opening. Insulating layers are installed inside the outer cylinder of the gas-phase power mill and on the inner wall of the charge chamber.

[0046] Large particles separated by the classifying impeller that do not meet the required size are returned to the collision zone via the falling zone for further collision crushing. These particles are already charged in the charge chamber, and there is a repulsive force between them, which is not conducive to collision crushing in the collision zone. Ions generated by the ion generator in the falling zone are carried by compressed gas through nozzles into the falling zone to neutralize the large particles, eliminating the charge repulsion between particles and facilitating the collision crushing process.

[0047] The above solution provided in this embodiment, by setting a charge chamber in the gas phase power mill 211 and using a first ion generator 204 to deliver first ions into the charge chamber, creates an electrical environment for the first ions within the charge chamber. When the powder passes through the charge chamber, all powder particles carry the first ions, resulting in all powder particles having the same charge. Based on the principle of like charges repelling each other, this prevents the powder particles from agglomerating. During the descent of large particles through the falling zone, a second ion generator 203 delivers second ions with the opposite charge to the first ions into the falling zone. This neutralizes the first and second ions on the descending large powder particles, forming uncharged particles that directly descend to the supersonic airflow input area for further pulverization. Using the solution of this application, the repulsive force of like charges can prevent the interaction and adsorption forces between ultrafine particles due to their close proximity, improving the dispersion of ultrafine particles and preventing agglomeration.

[0048] Furthermore, the charge chamber in the gas-phase power mill creates a large particle settling zone, effectively preventing large particles from the classifying impeller from directly entering the charge chamber area without entering the supersonic airflow input zone. This avoids large particles entering the classifying impeller without undergoing collision and crushing. The charge chamber also reduces the separation load on the classifying impeller. In addition, the charge chamber separates the collided ultrafine powder from the separated large particles, allowing for the application of different electrical charges to qualified and unqualified materials within the power mill.

[0049] Preferably, the system for preventing the agglomeration of ultrafine powder further includes a third ion generator 209, which outputs first ions to the discharge pipe of the gas-phase power mill 211; a third charge measuring device A3, installed in the discharge pipe, for measuring the charge of the powder in the discharge pipe; and a third charge controller 208, which receives the charge of the powder output by the third charge measuring device A3 and controls the power of the third ion generator 209 according to the difference between the charge of the powder and a third preset charge to control the amount of first ions entering the discharge pipe. During the high-speed rotation of the classifying impeller and the friction with the equipment walls and pipes, ultrafine powder inevitably generates static electricity, which weakens the charge of the ultrafine powder, leading to continued agglomeration during subsequent conveying and separation processes. Therefore, setting an anti-static charge nozzle at the product discharge port of the gas-phase power mill to recharge the ultrafine powder stream again can eliminate the influence of static electricity and further enhance the anti-agglomeration properties of the ultrafine powder.

[0050] In the above scheme, three independent ion generators—a first ion generator, a second ion generator, and a third ion generator—are set up. These three ion generators operate independently, producing either cations or anions based on the required charge properties and magnitudes at different locations within the gas-phase power mill. Charge measuring devices are installed at the charge chamber, the falling zone, and the discharge port to monitor the charge state of the material at these three locations in real time. Three corresponding charge controllers are installed within the system. The charge detection signals from the material at each of the three locations are sent to the corresponding controllers. The controllers perform a series of logical operations, including analyzing and comparing the charge with setpoints, adjusting the power of the three ion generators, and continuing to feed back the charge signals, ultimately controlling the charge of the material within a reasonably set range while preventing the ion generators from operating under excessive load, thus achieving energy-saving effects.

[0051] Based on the above principle, the second preset charge is zero to ensure that the large particle material is fully charged, while avoiding excessive load on the ion generator, thus achieving energy saving. The first and third preset charges are charge thresholds that cause the ultrafine powders to repel each other. These charge thresholds can be determined through empirical values ​​or simulation experiments.

[0052] Furthermore, the system for preventing the agglomeration of ultrafine powder also includes a fan 201, a first ion chamber 207, one inlet of which is connected to the outlet of the fan 201 and the other inlet of which is connected to the outlet of the first ion generator 204. The first ion chamber 207 mixes the airflow output by the fan 201 with the first ions generated by the first ion generator 204 to form a first ion wind, which is then transported to the charge chamber. A second ion chamber 206 has one inlet connected to the outlet of the fan 201 and the other inlet connected to the outlet of the second ion generator 203. The second ion chamber 206 mixes the airflow output by the fan 201 with the second ions generated by the second ion generator 203 to form a second ion wind, which is then transported to the landing zone. The third ion chamber 210 has one inlet connected to the outlet of the blower 201 and the other inlet connected to the outlet of the third ion generator 209. The third ion chamber 210 mixes the airflow output from the blower 201 with the first ions generated by the third ion generator 209 to form a third ion wind, which is then delivered to the discharge pipe. In this design, the gas outlet of the blower 201 is divided into three paths, and the airflow and velocity to the charge chamber, the falling zone, and the discharge port can be flexibly adjusted via valves to regulate the disturbance of the ion wind on the material, achieving a better mixing effect between the material and the ion wind.

[0053] Furthermore, the system also includes a first pressure sensor located in the charge chamber to detect the pressure value inside the charge chamber; a second pressure sensor located in the landing zone to detect the pressure value in the landing zone; and a third pressure sensor located in the discharge pipe to detect the pressure value in the discharge pipe. The fan controller receives the pressure values ​​detected by the first, second, and third pressure sensors and controls the fan power based on the pressure value detection results of each sensor. When the fan is operating, the airflow pressure it provides is sufficient to carry ions into their corresponding areas. Therefore, the airflow pressure provided by the fan must be greater than the pressure values ​​of each area to ensure that the first ion wind enters the charge chamber, the second ion wind enters the landing zone, and the third ion wind enters the discharge pipe. By detecting the pressure values ​​of each area, the system determines whether the fan pressure is sufficient, thereby adjusting the fan power.

[0054] Preferably, a plurality of first ion inlets are uniformly arranged on the cylindrical body of the charge chamber, and the plurality of first ion inlets are evenly distributed on the cylindrical body. Further, the plurality of first ion inlets are arranged in three rows; wherein: the first ion inlets in the middle row are horizontally arranged, the first ion inlets in the upper row are inclined downward, and the first ion inlets in the lower row are inclined upward. The charge chamber is arranged with three layers of first ion inlets, and the first ion inlets enter the charge chamber from outside the gas phase power mill. The first ion air enters the charge chamber through the first ion inlets. There are no fewer than 6 first ion inlets evenly arranged along the circumference. The first ion inlets in the bottom layer are arranged upward at an angle of 15° between the elevation angle projection and the circumferential plane, and the first ion inlet in the circumferential plane is arranged at an angle of 18° between the circumferential plane angle projection and the circumferential radial plane; the first ion inlets in the top layer are arranged downward at an angle of 15° between the elevation angle projection and the circumferential plane, and the first ion inlets in the middle layer are arranged horizontally at an angle of 0° between the elevation angle projection and the circumferential plane, and the first ion inlets in the circumferential plane are arranged at an angle of 18° between the circumferential plane angle projection and the circumferential radial plane. Due to the arrangement of the first ion inlet, the blowing of the first ion wind can cause the material rising in the charge chamber to generate horizontal swirling and vertical back mixing, enabling the ultrafine powder to be fully charged. Due to the repulsive force of like charges, the ultrafine powder achieves an anti-agglomeration effect. In the scheme of this application, ions generated by the charge chamber ion generator are carried by compressed gas through the first ion inlet into the charge chamber, where they come into contact with the fluid of the ultrafine powder, causing the ultrafine powder to acquire the same charge. Because the repulsive force of like charges prevents the ultrafine particles from generating interaction and adsorption forces due to their close proximity, the dispersion of the ultrafine particles can be improved, preventing agglomeration.

[0055] Preferably, multiple second ion inlets are provided at the upper part of the landing zone, and these inlets are inclined downwards. The second ion inlets bring a second ion wind with the opposite charge to that of the charge chamber into the landing zone. One layer of second ion inlets is arranged at the upper end of the landing zone, with six inlets evenly distributed along the circumference of the outer cylinder of the gas-phase power mill. The angle between the vertical projection of the second ion inlet and the circumferential plane is 15° downwards, and the angle between the circumferential projection of the second ion inlet and the radial direction is 30°. Due to the arrangement of the second ion inlets, the second ion wind forms a swirling flow within the landing zone, enabling large particles to fully contact the second ion wind and neutralize the first ions carried by the large particles in the charge chamber.

[0056] Furthermore, multiple third ion inlets are arranged along the circumference of the discharge pipe and along the pipe's extension direction at the discharge port. These third ion inlets are inclined along the discharge direction. After passing through the classifying impeller, ultrafine powder of acceptable size exits through the discharge pipe; larger particles of unacceptable size are separated by the centrifugal force of the classifying impeller and enter the settling zone. Preferably, the discharge pipe has two third ion inlets. The angle between the third ion inlet and the horizontal direction is 20°. A third ion air jet with the same charge as the charge chamber is injected into the discharge pipe, and the pressure of the third ion air is greater than the pressure in the outlet pipe. Due to the arrangement of the third ion inlets, the third ion air forms a swirling flow in the outlet pipe, enabling the ultrafine material stream to fully contact the first ion air, ensuring sufficient secondary charging of the ultrafine powder, eliminating the influence of secondary static electricity, and further enhancing the anti-agglomeration properties of the ultrafine powder.

[0057] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A system for preventing the agglomeration of ultrafine powders, characterized in that, include: The charge chamber is located in the gas phase power mill, above the supersonic airflow input position; A first ion generator outputs first ions to the charge chamber; A first charge measuring device is installed at the outlet of the charge chamber and is used to measure the charge of the powder output from the charge chamber; The first charge controller receives the powder charge output by the first charge measuring device and controls the power of the first ion generator according to the difference between the powder charge and the first preset charge to control the amount of first ions entering the charge chamber. A second ion generator outputs second ions to the landing zone between the charge chamber and the gas-phase power mill, the second ions having the opposite charge to the first ions; The second charge measuring device is located at the bottom opening of the landing zone and is used to measure the charge of the powder falling into the supersonic airflow input area from the landing zone. The second charge controller receives the powder charge output by the second charge measuring device and controls the power of the second ion generator based on the difference between the powder charge and the second preset charge to control the amount of second ions entering the landing zone.

2. The system for preventing agglomeration of ultrafine powders according to claim 1, characterized in that, Also includes: The third ion generator outputs the first electro-ions to the discharge pipe of the gas phase power mill. A third charge measuring device is installed in the discharge pipe to measure the charge of the powder in the discharge pipe; The third charge controller receives the powder charge output by the third charge measuring device and controls the power of the third ion generator based on the difference between the powder charge and the third preset charge to control the amount of first ions entering the discharge pipe.

3. The system for preventing agglomeration of ultrafine powders according to claim 2, characterized in that: The second preset charge level is zero; The first preset charge and the third preset charge are charge thresholds that cause the ultrafine powders to repel each other.

4. The system for preventing agglomeration of ultrafine powders according to claim 3, characterized in that, Also includes: Fan; The first ion chamber has one inlet connected to the outlet of the fan and the other inlet connected to the outlet of the first ion generator. The first ion chamber mixes the airflow output by the fan with the first ions generated by the first ion generator to form a first ion wind, which is then transported to the charge chamber. The second ion chamber has one inlet connected to the outlet of the fan and the other inlet connected to the outlet of the second ion generator. The second ion chamber mixes the airflow output by the fan with the second ions generated by the second ion generator to form a second ion wind, which is then transported to the landing area.

5. The system for preventing agglomeration of ultrafine powders according to claim 4, characterized in that, Also includes: The third ion chamber has one inlet connected to the outlet of the blower and the other inlet connected to the outlet of the third ion generator. The third ion chamber mixes the airflow output by the blower with the first ions generated by the third ion generator to form a third ion airflow, which is then transported to the discharge pipe.

6. The system for preventing agglomeration of ultrafine powders according to claim 5, characterized in that, Also includes: A first pressure sensor is disposed in the charge chamber and is used to detect the pressure value inside the charge chamber; A second pressure sensor is installed in the landing zone to detect the pressure value in the landing zone; A third pressure sensor is installed in the discharge pipe to detect the pressure value of the discharge pipe; The controller of the blower receives pressure values ​​detected by the first pressure sensor, the second pressure sensor, and the third pressure sensor, and controls the power of the blower according to the pressure value detection results of each pressure sensor to ensure that the first ion wind enters the charge chamber, the second ion wind enters the falling zone, and the third ion wind enters the discharge pipe.

7. The system for preventing agglomeration of ultrafine powders according to any one of claims 1-6, characterized in that: Multiple first ion inlets are uniformly arranged on the cylindrical body of the charge chamber, and the multiple first ion inlets are uniformly distributed on the cylindrical body.

8. The system for preventing agglomeration of ultrafine powders according to claim 7, characterized in that: The multiple first ion inlets are arranged in three rows; wherein: the first ion inlets in the middle row are arranged horizontally, the first ion inlets in the upper row are arranged inclined downwards, and the first ion inlets in the lower row are arranged inclined upwards.

9. The system for preventing agglomeration of ultrafine powders according to any one of claims 1-6, characterized in that: The upper part of the landing zone is provided with multiple second ion inlets, and the multiple second ion inlets are inclined downward.

10. The system for preventing agglomeration of ultrafine powders according to any one of claims 2-6, characterized in that: Multiple third ion inlets are arranged along the circumference of the pipe and along the extension direction of the pipe, and the third ion inlets are inclined along the discharge direction.

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