Superfine powder airflow crushing and circulating grading device

Abstract

The invention relates to the technical field of powder material airflow crushing and grading, in particular to an ultrafine powder airflow crushing and circulating grading device. Comprising a grading chamber, a crushing chamber and a flow guide assembly, the grading chamber is positioned at the top of the crushing chamber and is communicated with the crushing chamber; the lower portion of the crushing chamber working cavity is provided with a crushing area used for crushing fed materials, the upper portion of the crushing chamber working cavity is provided with a grading area, and a grading wheel is arranged in the grading area and used for guiding powder obtained after the fed materials are crushed into the grading chamber. The flow guide assembly is installed in the crushing chamber, a flow guide channel used for airflow to drive powder to flow is defined in the crushing chamber, the top of the flow guide channel communicates with the grading wheel of the grading area of the crushing chamber, and the bottom of the flow guide channel communicates with the crushing area of the crushing chamber. The device not only can improve the material crushing efficiency and the productivity, but also reduces the condition that a large amount of coarse powder abrades blades when the grading wheel rotates at a high speed, thereby prolonging the service life of equipment.

Description

Technical Field

[0001] The invention relates to the technical field of airflow crushing and classification of powder materials, in particular to an ultrafine powder airflow crushing circulation classification device. Background Art

[0002] At present, among the negative electrode materials of sodium ion batteries, biomass hard carbon materials are widely available, have simple synthesis processes, are environmentally friendly and renewable, and have certain economic benefits. They are high-quality carbon sources for negative electrode materials of sodium ion batteries. In actual production, the requirements for the particle size, purity and particle size distribution of ultrafine powder products have also increased accordingly. As a technology for airflow crushing and grading in the ultrafine powder production and manufacturing industry, its development has attracted more and more widespread attention from the world. In the airflow classification step, in order to meet the production capacity requirements, the powder material is crushed to a suitable particle size and then graded and transported. Usually, a large-scale airflow conveying device is used to increase the powder flow rate. At the same time, strict requirements are placed on the target particle size of the powder crushing. Therefore, the equipment process capability is required to be high. When the equipment is running, there are problems such as wear of the grading wheel, uneven powder grading particle size, poor product consistency, and excessive current of the motor of the extension machine, which leads to a decrease in processing efficiency.

[0003] Defects and shortcomings of existing technologies: The existing air flow crushing and classification technology is based on the centripetal force generated by the rotation of the classifying wheel, negative pressure suction, compressed air from bottom to top and the gravity of the powder itself. After the fine powder of qualified particle size passes through the gap between the classifying wheel blades, it is transported to the next process under negative pressure; the unqualified coarse powder cannot be returned to the crushing area in time for further crushing, and the airflow drives the coarse powder to continue to be enriched on the outside of the classifying wheel.

[0004] This will cause the airflow to carry a large amount of coarse powder, which will continuously wear the outer blades of the classifying wheel and affect the life of the classifying wheel. At the same time, a large amount of coarse powder cannot be returned to the crushing area for crushing in time, resulting in low crushing efficiency and low fine powder yield, which affects production capacity. In addition, the airflow carries a large amount of coarse powder, which increases the rotation resistance of the classifying wheel and increases the load on the equipment, affecting the classification efficiency. A large amount of coarse powder is enriched at the waistline of the classifying wheel and collides with each other. The centrifugal force on the coarse powder is unstable (decreases), and the uncrushed coarse powder is pumped to the discharge port by negative pressure, which affects the particle size of the fine powder and the uneven particle size of the product. Therefore, it is urgent to solve this problem.

[0005] The above contents are only used to assist in understanding the technical solution of the present invention, and do not constitute an admission that the above contents are the closest prior art. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an ultrafine powder airflow crushing circulation classification device, which can not only improve the material crushing efficiency and increase the production capacity, but also reduce the situation where a large amount of coarse powder around the classifying wheel wears the blades when the classifying wheel rotates at high speed, thereby increasing the life of the equipment.

[0007] To achieve the above object, the technical solution of the present invention is implemented as follows: an ultrafine powder airflow crushing circulation classification device comprises: a classification chamber, a crushing chamber and a guide assembly; the classification chamber is located at the top of the crushing chamber and is connected to the crushing chamber; the lower part of the working chamber of the crushing chamber is set as a crushing zone for crushing the feed, the upper part of the working chamber of the crushing chamber is set as a classification zone, and a classification wheel is provided in the classification zone, and the classification wheel is used to guide the powder after the feed is crushed into the classification chamber;

[0008] The guide assembly is installed in the crushing chamber and encloses a guide channel in the crushing chamber for airflow to drive the powder to flow, and the top of the guide channel is connected to the grading wheel in the grading area of ​​the crushing chamber, and the bottom is connected to the crushing area of ​​the crushing chamber.

[0009] Preferably, the grading wheel is provided with trapezoidal blades; the trapezoidal blades include trapezoidal pieces and rectangular pieces; the trapezoidal pieces are configured as inverted right-angled trapezoids, the bottom ends of the trapezoidal pieces are connected to the rectangular pieces, and the right-angled sides of the trapezoidal pieces are flush with one side of the rectangular pieces.

[0010] Preferably, the height ratio of the trapezoidal sheet to the rectangular sheet is h / H=0.1-0.15, the width ratio of the top of the trapezoidal sheet to the width of the rectangular sheet is d / D=1.5-2; the angle between the hypotenuse of the trapezoidal sheet and the other side of the rectangular sheet is 135°-153°.

[0011] Preferably, the guide assembly includes an inner circulation hood; the inner circulation hood is arranged in the grading area of ​​the crushing chamber, and the gap between the inner circulation hood and the inner wall of the crushing chamber constitutes a first channel for the powder to flow with the airflow; the first channel discharge port of the first channel is connected to the crushing area of ​​the crushing chamber, and the entrance is connected to the top of the grading wheel; the trapezoidal piece of the trapezoidal blade is located at the entrance of the first channel; the gap between the rectangular piece of the trapezoidal blade and the inner wall of the inner circulation hood constitutes a second channel for the powder to flow with the airflow, and the bottom end of the second channel is connected to the crushing area of ​​the crushing chamber.

[0012] Preferably, the guide assembly also includes at least 3 connecting rods; the connecting rods are arranged in the first channel and are evenly spaced along the circumference of the inner circulation cover, and one end of the connecting rod is connected to the outer wall of the inner circulation cover, and the other end is connected to the inner wall of the crushing chamber; a vibrator is provided at the discharge port of the first channel.

[0013] Preferably, the guide assembly includes a buffer bin; the buffer bin is arranged on one side of the crushing chamber, and the buffer bin feed port is connected to the top of the grading wheel, and the trapezoidal piece of the trapezoidal blade is opposite to the buffer bin feed port; the discharge port of the buffer bin is connected to the crushing area of ​​the working cavity of the crushing chamber.

[0014] Preferably, a feeding screw is provided at the discharge port of the buffer bin; one end of the feeding screw is connected to the discharge port of the buffer bin, and the other end is connected to the crushing area of ​​the working cavity of the crushing chamber.

[0015] Preferably, a negative pressure exhaust port is provided on the top of the buffer bin, and a pulse dust collector is provided at the negative pressure exhaust port; the pulse dust collector is connected to the dust bag in the buffer bin; and a vibrator is provided on the side wall outside the buffer bin.

[0016] Preferably, it further comprises a motor; the motor is installed on the top of the grading chamber, and the driving shaft of the motor passes through the grading chamber and is connected to the grading wheel shaft in the crushing chamber.

[0017] Preferably, an observation port is provided at the bottom end of the crushing chamber; a feed inlet and a Laval nozzle are provided on the side of the bottom of the crushing chamber, and the feed inlet is located above the Laval nozzle.

[0018] The beneficial effects of the present invention are embodied in:

[0019] (1) The device provided by the present invention can improve the classification effect in the prior art, so that the materials in the process are subdivided into three types (fine powder, medium powder, and coarse powder), and the three types of powders are processed separately. This can not only increase the material cycle classification and crushing time, improve the material crushing efficiency, and increase production capacity. At the same time, it can reduce the situation where a large amount of coarse powder around the classifying wheel rotates at high speed and wears the blades, thereby increasing the life of the equipment.

[0020] (2) The device provided by the present invention can reduce the running resistance of the classifying wheel, reduce the equipment load, improve the stable operation capability of the equipment, and improve the uniformity of the fine powder with qualified particle size. Circular classification and crushing can improve the fine powder yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 It is a structural schematic diagram of the parallel scheme of the present invention;

[0023] Figure 3 It is a schematic diagram of the structure of the trapezoidal blade of the present invention.

[0024] Description of reference numerals:

[0025] 10. Motor; 11. Drive shaft; 12. Trapezoidal blades; 121. Trapezoidal blades; 122. Rectangular blades; 20. Classification chamber; 21. Classification outlet; 30. Crushing chamber; 31. Internal circulation cover; 32. First channel;

[0026] 321, first channel outlet; 322, connecting rod; 33, Laval nozzle; 34, feed inlet;

[0027] 35. Observation port; 36. Cover plate; 41. Vibrator; 50. Buffer bin; 60. Pulse dust collector; 61. Dust bag; 71. Feed screw. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] See also Figure 1 to Figure 2 As shown: The present invention provides an ultrafine powder airflow crushing circulation classification device, including: a motor 10, a classification chamber 20, a crushing chamber 30 and a guide component.

[0031] The classification chamber 20 is located at the top of the crushing chamber 30 and is connected to the crushing chamber 30. The motor 10 is installed at the top of the classification chamber 20, and the drive shaft 11 of the motor 10 passes through the classification chamber 20 and is connected to the classification wheel 13 in the crushing chamber 30. The lower part of the working chamber of the crushing chamber 30 is set as a crushing area for crushing the feed, and the upper part of the working chamber of the crushing chamber 30 is set as a classification area, and the classification area is provided with a classification wheel 13, which is used to introduce the powder after the feed is crushed into the classification chamber 20.

[0032] A cover plate 36 is provided at the top of the crushing chamber 30, and the cover plate 36 is detachably connected thereto. When the equipment is in operation, the cover plate 36 prevents the material from escaping, and the grading wheel 13 can be taken out from the cover plate 36 for fixed-point maintenance of the equipment. An openable observation port 35 is provided at the bottom of the crushing chamber 30; a feed inlet 34 and a Laval nozzle 33 are provided on the side of the bottom of the crushing chamber 30, and the feed inlet 34 is located above the Laval nozzle 33.

[0033] In specific applications, the material to be crushed enters the crushing area through the feed inlet 34. After the compressed air enters from the Laval nozzle 33, it is converted into a hypersonic airflow, causing the materials to collide with each other and gradually crush into powder of the target particle size. The motor 10 drives the classifying wheel 13 to rotate at a high speed. The speed of the classifying wheel 13 driven by the motor 10 can be adjusted arbitrarily, forming a strong centrifugal force in the classification area. Driven by the classifying wheel 13, some powders with finer particles enter the classification chamber 20 and are transported to the next production link along the classification outlet 21 of the classification chamber 20.

[0034] The guide assembly is installed in the crushing chamber 30 and encloses a guide channel in the crushing chamber 30 for airflow to drive the powder to flow, and the top of the guide channel is connected to the grading wheel 13 in the grading area of ​​the crushing chamber 30, and the bottom is connected to the crushing area of ​​the crushing chamber 30.

[0035] Through such an arrangement, the material to be crushed can circulate between the classification zone and the crushing zone of the crushing chamber 30 and be crushed repeatedly until it reaches the conveying standard of the classification wheel 13 and enters the classification chamber 20.

[0036] In order to make the powders of different diameters after the material is crushed to circulate smoothly along the guide channel, a trapezoidal blade 12 is provided on the classifying wheel 13. The trapezoidal blade 12 includes a trapezoidal piece 121 and a rectangular piece 122; the trapezoidal piece 121 is set as an inverted right-angled trapezoid, the bottom end of the trapezoidal piece 121 is connected to the rectangular piece 122, and the right-angled side of the trapezoidal piece 121 is flush with one side of the rectangular piece 122.

[0037] The height ratio of the trapezoidal piece 121 to the rectangular piece 122 is h / H=0.1-0.15, the width ratio of the top of the trapezoidal piece 121 to the width of the rectangular piece 122 is d / D=1.5-2; the angle between the hypotenuse of the trapezoidal piece 121 and the other side of the rectangular piece 122 is 135°-153°.

[0038] Due to the trapezoidal structural design of the trapezoidal blades 12, the centrifugal force of the outer area of ​​the classifying wheel 13 can be increased, that is, by changing the flow direction of the airflow at the trapezoidal piece 121 of the trapezoidal blade 12, the airflow is promoted to carry the powder of the corresponding diameter into the guide channel, thereby completing the powder screening, and the powder is transported to the crushing area along the guide channel to achieve secondary circulation crushing.

[0039] The flow guide assembly includes an inner circulation cover 31 and a connecting rod 322 .

[0040] The inner circulation cover 31 is arranged in the grading area of ​​the crushing chamber 30, and the gap between the inner circulation cover 31 and the inner wall of the crushing chamber 30 constitutes a first channel 32 for the powder to flow with the airflow; the first channel discharge port 321 of the first channel 32 is connected to the crushing area of ​​the crushing chamber 30, and the entrance is connected to the top of the grading wheel 13, and the trapezoidal piece 121 of the trapezoidal blade 12 is located at the entrance of the first channel 32, so that when the grading wheel 13 rotates, the trapezoidal blade 12 introduces the powder or powder of corresponding diameter into the first channel 32.

[0041] The gap between the rectangular piece 122 of the trapezoidal blade 12 and the inner wall of the inner circulation cover 31 constitutes a second channel for the powder to flow with the airflow, and the bottom end of the second channel is connected to the crushing area of ​​the crushing chamber 30.

[0042] There are at least three connecting rods 322; the connecting rods 322 are arranged in the first channel 32 and are arranged at equal intervals along the circumference of the inner circulation cover 31, and one end of the connecting rod 322 is connected to the outer wall of the inner circulation cover 31, and the other end is connected to the inner wall of the crushing chamber 30; in order to facilitate the powder at the first channel discharge port 321 to fall smoothly into the crushing area, an exciter 41 is provided at the first channel discharge port 321, and the exciter 41 is installed on the outer wall of the crushing chamber 30.

[0043] When the motor 10 drives the classifying wheel 13 to rotate at a high speed, a strong centrifugal force is formed in the classifying area. The gas-powder mixture entering the classifying area first enters the periphery of the classifying wheel 13.

[0044] Under the centrifugal force of the classifying wheel 13, the medium-sized or heavy medium-powder particles are subjected to a larger centrifugal force, and under the auxiliary centrifugal action of the trapezoidal blades 12, the medium-sized or heavy medium-powder particles are transported to the first channel 32. The large-sized or heavy coarse powder particles are subjected to the greatest centrifugal force, so they are thrown to the area between the outer periphery of the classifying wheel 13 and the inner wall of the inner circulation cover 31, that is, along the second channel, and naturally fall into the crushing area for further crushing.

[0045] Small or light materials are less affected by centrifugal force and hover inside the classifying wheel 13. They are affected by the negative pressure of the classifying outlet 21 of the classifying chamber 20 and are brought to the classifying outlet 21. They are transported along the pipeline to the next component to be classified or collected.

[0046] The centrifugal force generated at the grading wheel 13 can be adjusted by adjusting the speed of the grading wheel 13 through frequency conversion, and with the assistance of the guide assembly and the trapezoidal blades 12, the materials in the grading area can be automatically screened into three types: fine powder (qualified particle size), medium powder (medium particle size), and coarse powder (large particle size), and the three types of powders are processed separately. This not only achieves the purpose of separating materials of specified particle size, but also prevents the compressed air from continuously entraining a large amount of medium powder and coarse powder upward to stay around the grading wheel 13, reducing the waistline wear of the grading wheel 13. At the same time, it increases the time that the medium powder and coarse powder stay in the crushing area, thereby improving the crushing efficiency and the purpose of efficient material circulation and classification.

[0047] Example 2

[0048] According to the design of the trapezoidal blades 12 of Example 1 and the core concept of ultrafine powder circulation classification, in addition to designing the structure of the guide channel in the crushing chamber 30, the circulation classification chamber can also be designed separately, such as Figure 3 As shown:

[0049] The guide assembly includes a buffer bin 50; the buffer bin 50 is arranged on one side of the crushing chamber 30, and the feed port of the buffer bin 50 is connected to the top of the grading wheel 13, and the trapezoidal piece 121 of the trapezoidal blade 12 is opposite to the feed port of the buffer bin 50, and the discharge port of the buffer bin 50 is connected to the crushing area of ​​the working cavity of the crushing chamber 30.

[0050] A negative pressure exhaust port is provided at the top of the buffer bin 50, and a pulse dust collector 60 is provided at the negative pressure exhaust port; the pulse dust collector 60 is connected to the dust bag 61 in the buffer bin 50; an exciter 41 is provided on the side wall outside the buffer bin 50. A feeding screw 71 is provided at the discharge port of the buffer bin 50; one end of the feeding screw 71 is connected to the discharge port of the buffer bin 50, and the other end is connected to the crushing area of ​​the working cavity of the crushing chamber 30.

[0051] In specific application, the structure of the trapezoidal piece 121 at the top of the trapezoidal blade 12 allows the medium powder with larger particles to enter the buffer bin 50, and the medium powder is re-transported to the crushing chamber of the crushing chamber 30 through the vibrator 41 and the feeding screw 71 at the bottom of the buffer bin 50.

[0052] As the airflow carries the medium powder from the classification area into the buffer bin 50, in order to ensure the air pressure balance in the buffer bin 50, the air in the buffer bin 50 is discharged through the negative pressure exhaust port, and the medium powder is intercepted by the dust bag 61 and falls back into the bin. The pulse dust collector 60 cleans the dust on the dust bag 61 by reverse pulse blowing to prevent the dust bag 61 from being blocked.

[0053] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. Ultrafine powder air flow crushing circulation classification device, characterized in that: include: A grading chamber (20), a crushing chamber (30) and a guide assembly; the grading chamber (20) is located at the top of the crushing chamber (30) and is in communication with the crushing chamber (30); the lower part of the working chamber of the crushing chamber (30) is set as a crushing zone for crushing the feed, the upper part of the working chamber of the crushing chamber (30) is set as a grading zone, a grading wheel (13) is provided in the grading zone, and the grading wheel (13) is used to guide the powder after the feed is crushed into the grading chamber (20); the guide assembly is installed in the crushing chamber (30), and encloses a guide channel in the crushing chamber (30) for airflow to drive the powder to flow, and the top of the guide channel is in communication with the grading wheel (13) in the grading zone of the crushing chamber (30), and the bottom is in communication with the crushing zone of the crushing chamber (30).

2. The ultrafine powder air flow crushing circulation classification device according to claim 1 is characterized in that The grading wheel (13) is provided with a trapezoidal blade (12); the trapezoidal blade (12) comprises a trapezoidal piece (121) and a rectangular piece (122); the trapezoidal piece (121) is configured as an inverted right-angled trapezoid, the bottom end of the trapezoidal piece (121) is connected to the rectangular piece (122), and the right-angled side of the trapezoidal piece (121) is flush with one side of the rectangular piece (122).

3. The ultrafine powder air flow crushing circulation classification device according to claim 2 is characterized in that The height ratio of the trapezoidal piece (121) to the rectangular piece (122) is h / H=0.1-0.15, the width ratio of the top of the trapezoidal piece (121) to the width of the rectangular piece (122) is d / D=1.5-2; the angle between the hypotenuse of the trapezoidal piece (121) and the other side of the rectangular piece (122) is 135°-153°.

4. The ultrafine powder air flow pulverizing circulation classification device according to claim 2 or 3, characterized in that The guide assembly comprises an inner circulation cover (31); the inner circulation cover (31) is arranged in the classification area of ​​the crushing chamber (30), and the gap between the inner circulation cover (31) and the inner wall of the crushing chamber (30) constitutes a first channel (32) for the powder to flow with the airflow; the first channel discharge port (321) of the first channel (32) is connected to the crushing area of ​​the crushing chamber (30), and the entrance is connected to the top of the classification wheel (13); the trapezoidal piece (121) of the trapezoidal blade (12) is located at the entrance of the first channel (32); the gap between the rectangular piece (122) of the trapezoidal blade (12) and the inner wall of the inner circulation cover (31) constitutes a second channel for the powder to flow with the airflow, and the bottom end of the second channel is connected to the crushing area of ​​the crushing chamber (30).

5. The ultrafine powder air flow crushing circulation classification device according to claim 4 is characterized in that The guide assembly further comprises at least three connecting rods (322); the connecting rods (322) are arranged in the first channel (32) and are arranged at equal intervals along the circumference of the inner circulation cover (31), and one end of the connecting rod (322) is connected to the outer wall of the inner circulation cover (31), and the other end is connected to the inner wall of the crushing chamber (30); a vibrator (41) is provided at the discharge port (321) of the first channel.

6. The ultrafine powder air flow pulverizing circulation classification device according to claim 2 or 3, characterized in that The guide assembly comprises a buffer bin (50); the buffer bin (50) is arranged on one side of the crushing chamber (30), and the feed port of the buffer bin (50) is connected to the top of the grading wheel (13), and the trapezoidal blade (121) of the trapezoidal blade (12) is opposite to the feed port of the buffer bin (50); the discharge port of the buffer bin (50) is connected to the crushing area of ​​the working cavity of the crushing chamber (30).

7. The ultrafine powder air flow crushing circulation classification device according to claim 6 is characterized in that A feeding screw (71) is provided at the discharge port of the buffer bin (50); one end of the feeding screw (71) is connected to the discharge port of the buffer bin (50), and the other end is connected to the crushing area of ​​the working cavity of the crushing chamber (30).

8. The ultrafine powder air flow crushing circulation classification device according to claim 7 is characterized in that A negative pressure exhaust port is provided at the top of the buffer bin (50), and a pulse dust collector (60) is provided at the negative pressure exhaust port; the pulse dust collector (60) is connected to a dust bag (61) in the buffer bin (50); and an exciter (41) is provided on the side wall outside the buffer bin (50).

9. The ultrafine powder airflow crushing circulation classification device according to claim 2 or 3, characterized in that , and also includes a motor (10); the motor (10) is installed on the top of the classification chamber (20), and the drive shaft (11) of the motor (10) passes through the classification chamber (20) and is connected to the shaft of the classification wheel (13) in the crushing chamber (30).

10. The ultrafine powder air flow crushing circulation classification device according to claim 9, characterized in that The bottom end of the crushing chamber (30) is provided with an observation port (35); the side of the bottom of the crushing chamber (30) is provided with a feed inlet (34) and a Laval nozzle (33), and the feed inlet (34) is located above the Laval nozzle (33).

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