A device for high-efficiency processing of superfine adhesive powder

Abstract

The application discloses a kind of ultrafine viscous powder high-efficiency processing device, including L valve, Venturi type stirring fluidized bed and cyclone separator.The center of the cylinder vertical riser of L valve is equipped with pulse airflow inlet, and the one side of cylinder horizontal pipe is equipped with auxiliary airflow inlet;Venturi type stirring fluidized bed is sequentially formed with circular table expansion section, cylinder throat pipe, circular table contraction section and cylinder inlet section from top to bottom, and the other side of the cylinder horizontal pipe is communicated with the cylinder throat pipe;The middle part of the circular table expansion section is equipped with discharge port, and the upper part is equipped with gas outlet;The lower end of the cylinder inlet section is equipped with cylinder gas collection section, and stirring mechanism is arranged in the cylinder inlet section.The application can improve the dispersibility of ultrafine viscous powder in airflow, can efficiently break up cluster, avoid local formation large cluster fixed bed, realize stable feeding and discharging, and the powder applicability is strong, simple structure, easy to operate, can realize the high-efficiency processing of ultrafine viscous powder.

Description

Technical Field

[0001] This invention relates to the field of powder engineering technology, and more specifically to an apparatus for the efficient processing of ultrafine viscous powders. Background Technology

[0002] According to Geldart particle classification, ultrafine viscous powders with a particle size of less than 30 μm have strong interparticle forces, making them difficult to fluidize normally in a fluidized bed. They typically form fluidized agglomerates at high gas velocities, severely affecting their gas-solid contact efficiency and mass and heat transfer rates. Applying an external force field can effectively reduce the size of fluidized agglomerates formed by ultrafine viscous powders, but this approach presents many challenges in practical applications, such as a small effective range of the sound field, high equipment cost, difficult installation, magnetic fields only applicable to magnetic materials, and complex structures, poor equipment stability, and difficulty in large-scale operation of vibration devices.

[0003] Compared to vibration fields, sound fields, and magnetic fields, stirring can generate shear force to directly break up fluidized agglomerates, resulting in a more significant effect. Chinese patent application CN1126447A discloses a stirring-assisted fluidized bed reactor for olefin polymerization. The main body of the stirrer is a hollow structure, and the stirring blades have vent holes. The stirrer provides a continuous gas flow channel, through which gas can flush the inner wall of the reactor and improve the flow state of particles in the fluidized bed. However, this solution can only prevent polymer particles from adhering to the reactor wall. Due to the limited strength of the hollow structure stirrer, the shearing effect of the stirring blades on the polymer particles in the reactor is weak, resulting in poor agglomeration breaking effect. Chinese patent application CN103638877A discloses a stirred fluidized bed olefin polymerization reactor. A stirrer is vertically installed inside the fluidized bed, and baffles are set on the wall. The rotating stirring blades and the stationary baffles are in a meshing state. Through the combined action of the stirring blades and the baffles, polymer particle agglomeration and adhesion to the inner wall of the reactor can be prevented. However, when processing sticky fine particles, especially ultrafine sticky powders, this method is prone to dust accumulation and blockage at the baffles inside the fluidized bed, affecting the normal operation of the agitator. Chinese patent application CN104587913A discloses a twin-shaft stirred vertical fluidized bed reactor, in which two sets of agitators mounted on stirring shafts form an interlocking system, preventing sticky particles from adhering to the agitator blades, shaft surface, and inner wall of the fluidized bed. However, this design has a relatively complex internal structure, and when processing ultrafine sticky powders, the interlocking points of the two agitators are prone to blockage, affecting normal operation.

[0004] Common fluidized bed reactors typically operate under positive pressure. To prevent backflow of gas from the bed into the hopper, the feeding system must simultaneously act as a material seal to prevent gas from flowing back into the hopper. However, when processing ultrafine viscous powders, due to their poor flowability, they are prone to arching and sticking to the walls within the hopper, causing blockages at pipe constrictions, flange switches, and screw feeders, thus affecting normal feeding. Chinese patent application CN101760246A discloses a biomass feeder for a pressurized fluidized bed gasifier, including a sealed hopper, a stirring device, and a screw feeder. This design improves the sealing and transmission structure of the stirring device and the screw feeder, incorporating two stainless steel wire stirring rods within the sealed hopper to address the arching and sticking of biomass powders. However, ultrafine viscous powders have strong compressibility and are prone to agglomeration, clogging the screw feeder and affecting normal feeding. Chinese patent application CN103691366A discloses an automatic feeding and feeding device for viscous powders in a fluidized bed, including a feed hopper, a storage hopper, a double-helix feed pipe, and a feeding pipeline. This design installs a vibrator at the bottom of the storage hopper, solving the bridging problem caused by the poor flowability of viscous powders during feeding. However, the double-helix feed pipe used in this design also suffers from clogging and compaction problems when processing ultrafine viscous powders.

[0005] In summary, while stirring can enhance the fluidization of viscous particles, existing stirring-assisted fluidization devices are complex in structure, have poor agglomeration breaking effects, and are poorly suited for ultrafine viscous powders. Furthermore, existing devices struggle to achieve stable and smooth feeding of ultrafine viscous powders. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the present invention aims to provide an apparatus for the efficient processing of ultrafine viscous powders.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A high-efficiency processing device for ultrafine viscous powder includes an L-type valve and a Venturi-type stirred fluidized bed;

[0009] The L-shaped valve consists of a cylindrical vertical tube and a cylindrical horizontal tube. The cylindrical vertical tube has a pulse airflow inlet at its center, and the cylindrical horizontal tube has an auxiliary airflow inlet on one side.

[0010] The Venturi-type stirred fluidized bed comprises, from top to bottom, a frustum expanding section, a cylindrical throat, a frustum contracting section, and a cylindrical inlet section. The inner diameter of the frustum expanding section gradually decreases from top to bottom, while the inner diameter of the frustum contracting section gradually increases from top to bottom. The inner diameter of the cylindrical throat is consistent with the inner diameter of the lower end of the frustum expanding section and the inner diameter of the upper end of the frustum contracting section, respectively. The other side of the cylindrical horizontal pipe is connected to the cylindrical throat. A discharge port is provided in the middle of the frustum expanding section, and an air outlet is provided at the top.

[0011] The lower end of the cylindrical inlet section is provided with a cylindrical gas collecting section, and the cylindrical inlet section and the cylindrical gas collecting section are separated by a gas distribution plate, which has a central hole; an air inlet is provided on one side of the cylindrical gas collecting section; and a stirring mechanism is provided inside the cylindrical inlet section.

[0012] Furthermore, the device also includes a cyclone separator, the air outlet is connected to the cyclone separator, and the lower end of the cyclone separator is connected to the return port at the upper part of the frustum expansion section through a return pipe; the return port is located below the air outlet.

[0013] Furthermore, the stirring mechanism includes a rotating shaft, a motor, and a stirring paddle; the upper part of the rotating shaft extends into the cylindrical gas collecting section and passes through the central hole of the gas distribution plate into the cylindrical inlet section; a stirring paddle is provided in the cylindrical inlet section, and the upper end of the rotating shaft is connected to the stirring paddle; the lower end of the rotating shaft is connected to the motor.

[0014] Furthermore, the length of the cylindrical inlet section along the axial direction is 0.1-0.3 times the diameter of its internal cross-section.

[0015] Furthermore, the angle between the generatrices on both sides of the axial section of the constricted frustum is 20-22°.

[0016] Furthermore, the cross-sectional diameter inside the cylindrical throat is 0.4-0.7 times the cross-sectional diameter inside the cylindrical inlet section.

[0017] Furthermore, the length of the cylindrical throat along the axial direction is 0.3-0.5 times the diameter of its internal cross-section.

[0018] Furthermore, the angle between the two generatrices of the axial section of the expanded frustum is 5-10°.

[0019] Furthermore, the stirring paddle rotates at a speed of 500-3000 rpm.

[0020] The present invention also provides a method for operating the above-mentioned high-efficiency processing device for ultrafine viscous powder, the specific process of which is as follows:

[0021] Ultrafine viscous powder enters from the upper end of the vertical cylindrical tube of the L-shaped valve, while pulsed airflow is simultaneously introduced through the pulsed airflow inlet of the vertical cylindrical tube, auxiliary airflow is introduced through the auxiliary airflow inlet, and airflow is introduced through the inlet. The ultrafine viscous powder is dispersed under the action of the pulsed airflow. The ultrafine viscous powder entering the horizontal cylindrical tube of the L-shaped valve is stably dispersed into the Venturi-type stirred fluidized bed under the combined action of the auxiliary airflow entering through the auxiliary airflow inlet and the negative pressure formed by the cylindrical throat. Under the action of the airflow in the cylindrical throat, the ultrafine viscous powder enters the frustum expansion section, where it forms agglomerates. As more ultrafine viscous powder is added, the agglomerate size gradually increases. When the ultrafine viscous powder at the bottom of the frustum expansion section... When the size of the powder agglomerates increases to the point that their weight exceeds the drag force generated by the airflow at the bottom of the truncated cone expansion section, the large-sized ultrafine viscous powder agglomerates at the bottom of the truncated cone expansion section will settle down along the cylindrical throat to the truncated cone contraction section and reach the cylindrical inlet section. The high-speed stirring mechanism in the cylindrical inlet section generates shear force and vortex airflow, which can break up the settled large-sized ultrafine viscous powder agglomerates. After being broken up, the dispersed ultrafine viscous powder moves upward along the truncated cone contraction section under the action of the airflow at the air inlet. After being accelerated through the cylindrical throat, it re-enters the truncated cone expansion section for fluidization. By repeating the above process, high dispersion and strong gas-solid contact continuous processing of ultrafine viscous powder can be achieved. When the expansion height of the ultrafine viscous powder in the truncated cone expansion section reaches the discharge port, it can overflow and be discharged.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. This invention uses an L-shaped pneumatic valve, and a pulse airflow inlet is set in the center of the cylindrical vertical tube of the L-shaped valve, which can realize the dispersion and feeding of ultrafine viscous powder. An auxiliary airflow is provided on one side of the cylindrical horizontal tube of the L-shaped valve, which can prevent ultrafine viscous powder from clogging the pipeline.

[0024] 2. This invention connects the outlet of an L-shaped valve to the cylindrical throat of a Venturi-structured stirred fluidized bed. Under the combined action of the airflow assisted by the horizontal tube of the L-shaped valve and the negative pressure formed by the cylindrical throat of the Venturi structure, stable feeding of ultrafine viscous powder can be achieved.

[0025] 3. This invention generates shear force and vortex airflow through high-speed stirring by a bottom-extended stirring paddle, which can efficiently shear and break up large agglomerates formed by ultrafine viscous powder, avoiding the formation of local unfluidized areas.

[0026] 4. The truncated section of the Venturi-structured stirred fluidized bed of the present invention can prevent ultrafine viscous powder from adhering to the wall surface, and the expanded section of the Venturi-structured stirred fluidized bed can improve the dispersibility of ultrafine viscous powder in the airflow, enhance gas-solid contact, and reduce segregation.

[0027] In summary, this invention can improve the dispersibility of ultrafine viscous powder in airflow, efficiently break up agglomerates, avoid the formation of large agglomerates in local fixed beds, achieve stable feeding and discharging, and has strong powder applicability, simple structure, and easy operation, enabling efficient processing of ultrafine viscous powder. Attached Figure Description

[0028] Figure 1 This is an overall schematic diagram of the high-efficiency processing device for ultrafine viscous powder in Embodiment 1 of the present invention;

[0029] Figure 2 This is a schematic diagram of the L-shaped valve in Embodiment 1 of the present invention;

[0030] Figure 3 This is a schematic diagram of the structure of a Venturi-type stirred fluidized bed in an embodiment of the present invention. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings. It should be noted that this embodiment is based on the present technical solution and provides detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to this embodiment.

[0032] Example 1

[0033] This embodiment provides a high-efficiency processing device for ultrafine viscous powder, such as... Figure 1-3 As shown, it includes an L-shaped valve 13, a Venturi-type stirred fluidized bed 20, and a cyclone separator 18. The L-shaped valve 13 and the cyclone separator 18 are respectively connected to the lower part and the upper part of the Venturi-type stirred fluidized bed 20.

[0034] The L-shaped valve 13 is composed of a cylindrical vertical tube and a cylindrical horizontal tube. The center of the cylindrical vertical tube is provided with a pulse airflow inlet 12, and one side of the cylindrical horizontal tube is provided with an auxiliary airflow inlet 11.

[0035] The Venturi-type stirred fluidized bed 20 consists of a frustum expanding section 14, a cylindrical throat 10, a frustum contracting section 9, and a cylindrical inlet section 8, arranged sequentially from top to bottom. The inner diameter of the frustum expanding section 14 gradually decreases from top to bottom, while the inner diameter of the frustum contracting section 9 gradually increases from top to bottom. The inner diameter of the cylindrical throat 10 is consistent with the inner diameter of the lower end of the frustum expanding section 14 and the inner diameter of the upper end of the frustum contracting section 9, respectively. The other side of the cylindrical horizontal pipe is connected to the cylindrical throat 10. The frustum expanding section 14 has a discharge port 15 in the middle and an air outlet 19 at the top. The air outlet 19 is connected to the cyclone separator 18. The lower end of the cyclone separator 18 is connected to the return port 16 at the top of the frustum expanding section 14 through a return pipe 17. The return port 16 is located below the air outlet 19.

[0036] The lower end of the cylindrical inlet section 8 is provided with a cylindrical gas collecting section 2. The cylindrical inlet section 8 and the cylindrical gas collecting section 2 are separated by a gas distribution plate 6, which has a central hole. An air inlet 4 is provided on one side of the cylindrical gas collecting section 2. A rotating shaft 5 is provided at the bottom of the cylindrical gas collecting section 2. The upper part of the rotating shaft 5 extends into the cylindrical gas collecting section 2 and passes through the central hole of the gas distribution plate 6 to extend into the cylindrical inlet section 8. A stirring paddle 7 is provided inside the cylindrical inlet section 8. The upper end of the rotating shaft 5 is connected to the stirring paddle 7. The lower end of the rotating shaft 5 is connected to the motor 1.

[0037] In this embodiment, the length of the cylindrical inlet section 8 along the axial direction is 0.1-0.3 times the diameter of its internal cross-section.

[0038] In this embodiment, the included angle between the generatrices on both sides of the axial section of the constricted frustum 9 is 20-22°.

[0039] In this embodiment, the cross-sectional diameter inside the cylindrical throat 10 is 0.4-0.7 times the cross-sectional diameter inside the cylindrical inlet section 8.

[0040] In this embodiment, the length of the cylindrical throat 10 along the axial direction is 0.3-0.5 times the diameter of its internal cross-section.

[0041] In this embodiment, the included angle between the two generatrices of the axial section of the frustum expansion segment 14 is 5-10°.

[0042] In this embodiment, the stirring paddle 7 rotates at a speed of 500-3000 rpm.

[0043] The working process of the above-mentioned device is as follows: Ultrafine viscous powder enters from the upper end of the cylindrical vertical tube of L-shaped valve 13, while pulse airflow is introduced from the pulse airflow inlet 12 of the cylindrical vertical tube, auxiliary airflow is introduced from the auxiliary airflow inlet 11, and airflow is introduced from the inlet 4. The ultrafine viscous powder is dispersed under the action of pulse airflow. The ultrafine viscous powder entering the cylindrical horizontal tube of L-shaped valve 13 is stably dispersed into the Venturi-type stirred fluidized bed 20 under the combined action of the auxiliary airflow and the negative pressure formed by the cylindrical throat 10. Under the action of the airflow (from the inlet 4 and the auxiliary airflow inlet 11) in the cylindrical throat 10, the ultrafine viscous powder enters the frustum expansion section 14. In the frustum expansion section 14, the ultrafine viscous powder forms agglomerates. As ultrafine viscous powder is continuously added, the agglomerate size gradually increases. When the size of the ultrafine viscous powder agglomerate at the bottom of the frustum expansion section 14 increases to a size greater than its weight, the ultrafine viscous powder agglomerates are released. When the airflow at the bottom of the frustum expansion section 14 generates drag, the large-sized ultrafine viscous powder agglomerates at the bottom of the frustum expansion section 14 will settle along the cylindrical throat 10 to the frustum contraction section 9 and reach the cylindrical inlet section 8. The high-speed stirring of the agitator 7 in the cylindrical inlet section 8 generates shear force and vortex airflow, which can break up the settled large-sized ultrafine viscous powder agglomerates. After being broken up and dispersed, the ultrafine viscous powder moves upward along the frustum contraction section 9 under the action of the airflow at the air inlet. After being accelerated through the cylindrical throat 10, it re-enters the frustum expansion section 14 for fluidization. This process is repeated, which can achieve high dispersion and strong gas-solid contact continuous processing of ultrafine viscous powder. When the expansion height of the ultrafine viscous powder in the frustum expansion section 14 reaches the discharge port 15, it can overflow and be discharged. When the airflow carries the powder upward to the position of the air outlet 19, it enters the cyclone separator 18. After being separated by the cyclone separator 18, the powder returns to the frustum expansion section 14 from the return pipe 17 and the return port 16, while the gas is discharged from the upper end of the cyclone separator 18.

[0044] Example 2

[0045] This embodiment provides an application example of the ultrafine viscous powder processing device described in Embodiment 1. The main device parameters are as follows: the cross-sectional diameter of the cylindrical inlet section is 100 mm, the length of the cylindrical inlet section along the axial direction is 10 mm, and the included angle between the generatrices on both sides of the axial section of the frustum-shaped contraction section is 20°. The cross-sectional diameter of the cylindrical throat is 40 mm, the length of the cylindrical throat along the axial direction is 20 mm, and the included angle between the generatrices on both sides of the axial section of the frustum-shaped expansion section is 10°. The ultrafine viscous powder in this embodiment is SiC with an average particle size of 1.82 μm. The gas velocity in the cylindrical inlet section is 0.02 m / s, the auxiliary airflow velocity on one side of the horizontal pipe of the L-shaped valve is 0.5 m / s, and the stirring paddle rotation speed is 500 rpm. The operating results show that the device of this embodiment can achieve high dispersion and strong gas-solid contact continuous processing of 1.82 μm SiC powder, effectively avoiding the formation of localized large agglomerates in the fixed bed.

[0046] Example 3

[0047] This embodiment provides an application example of the ultrafine viscous powder processing device described in Embodiment 1. The main device parameters are as follows: the diameter of the inner cross-section of the cylindrical inlet section is 100 mm, and the length of the cylindrical inlet section along the axial direction is 30 mm. The included angle between the generatrices on both sides of the axial section of the frustum-shaped contraction section is 22°, the diameter of the inner cross-section of the cylindrical throat is 70 mm, and the length of the cylindrical throat along the axial direction is 21 mm. The included angle between the generatrices on both sides of the axial section of the frustum-shaped expansion section is 5°. The ultrafine viscous powder in this embodiment is SiO2 with an average particle size of 4.61 μm. The gas velocity in the cylindrical inlet section is 0.15 m / s, the gas velocity of the auxiliary airflow on one side of the horizontal pipe of the L-shaped valve is 0.8 m / s, and the rotation speed of the stirring paddle is 3000 rpm. The operating results show that the device of this embodiment achieves high dispersion and strong gas-solid contact continuous processing of 4.61 μm SiO2 powder, effectively avoiding the formation of local large agglomerates in the fixed bed.

[0048] For those skilled in the art, various corresponding changes and modifications can be made based on the above technical solutions and concepts, and all such changes and modifications should be included within the protection scope of the claims of this invention.

Claims

1. A high-efficiency processing device for ultrafine viscous powder, characterized in that, Including L-type valves and Venturi-type stirred fluidized beds; The L-shaped valve consists of a cylindrical vertical tube and a cylindrical horizontal tube. The cylindrical vertical tube has a pulse airflow inlet at its center, and the cylindrical horizontal tube has an auxiliary airflow inlet on one side. The Venturi-type stirred fluidized bed comprises, from top to bottom, a frustum expanding section, a cylindrical throat, a frustum contracting section, and a cylindrical inlet section. The inner diameter of the frustum expanding section gradually decreases from top to bottom, while the inner diameter of the frustum contracting section gradually increases from top to bottom. The inner diameter of the cylindrical throat is consistent with the inner diameter of the lower end of the frustum expanding section and the inner diameter of the upper end of the frustum contracting section, respectively. The other side of the cylindrical horizontal pipe is connected to the cylindrical throat. A discharge port is provided in the middle of the frustum expanding section, and an air outlet is provided at the top. The lower end of the cylindrical inlet section is provided with a cylindrical gas collecting section, and the cylindrical inlet section and the cylindrical gas collecting section are separated by a gas distribution plate, which has a central hole; an air inlet is provided on one side of the cylindrical gas collecting section; a stirring mechanism is provided at the bottom of the Venturi-type stirred fluidized bed, and the stirring paddle of the stirring mechanism is located inside the cylindrical inlet section.

2. The high-efficiency processing device for ultrafine viscous powder according to claim 1, characterized in that, It also includes a cyclone separator, the air outlet is connected to the cyclone separator, and the lower end of the cyclone separator is connected to the return port at the top of the frustum expansion section through a return pipe; the return port is located below the air outlet.

3. The high-efficiency processing device for ultrafine viscous powder according to claim 1, characterized in that, The stirring mechanism also includes a rotating shaft and a motor; the upper part of the rotating shaft extends into the cylindrical gas collection section and passes through the central hole of the gas distribution plate into the cylindrical inlet section; the upper end of the rotating shaft is connected to the stirring paddle; the lower end of the rotating shaft is connected to the motor.

4. The high-efficiency processing device for ultrafine viscous powder according to claim 1, characterized in that, The length of the cylindrical inlet section along the axial direction is 0.1-0.3 times the diameter of its internal cross-section.

5. The high-efficiency processing device for ultrafine viscous powder according to claim 1, characterized in that, The angle between the generatrices on both sides of the axial section of the constricted frustum is 20-22 degrees.

6. The high-efficiency processing device for ultrafine viscous powder according to claim 1, characterized in that, The diameter of the cross-section inside the cylindrical throat is 0.4-0.7 times the diameter of the cross-section inside the cylindrical inlet section.

7. The high-efficiency processing device for ultrafine viscous powder according to claim 1, characterized in that, The length of the cylindrical throat along the axial direction is 0.3-0.5 times the diameter of its internal cross-section.

8. The high-efficiency processing device for ultrafine viscous powder according to claim 1, characterized in that, The angle between the two generatrices of the axial section of the expanded section of the frustum is 5-10 degrees.

9. The high-efficiency processing device for ultrafine viscous powder according to claim 1, characterized in that, The stirring paddle rotates at a speed of 500-3000 rpm.

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