Target jet mill and milling method

Abstract

The invention relates to a target jet mill which comprises a cylindrical barrel, and a fine powder channel and a coarse powder channel are formed in a grading chamber; the powder grader is mounted in the grading chamber, and a powder outlet of the powder grader is connected with the fine powder channel; the powder supply device is connected with the powder feeding chamber and is suitable for feeding powder into the powder feeding chamber; the powder spraying pipe is installed on the barrel of the powder crushing chamber, an inlet of the powder spraying pipe is connected with a first Venturi powder pump, and a powder return pipe is connected between the first Venturi powder pump and the coarse powder channel. The particle size of the separated crushed powder can be controlled through the powder grader, selection control is carried out in a large particle size range, fine powder meeting the set requirement is discharged from the fine powder channel, coarse powder is collected for centralized treatment while the fine powder is discharged and collected in time, and therefore the powder quality is improved. Coarse powder enters the second Venturi pump through the coarse powder channel and is sprayed out again to be smashed, and the smashing efficiency and quality are improved.

Description

Technical Field

[0001] The invention relates to the field of powder pulverizing equipment, and in particular to a target-type airflow mill and a powder making method. Background Art

[0002] Target jet mill is relatively rare among jet mills. Its principle is similar to that of fluidized bed jet mill, except that the pulverization method is that the high-speed airflow and powder collide with the rigid target head to achieve pulverization. The most common and advanced target jet mill is the disc target jet mill. Figure 1 As shown, a mixing cylinder 11 and a separation disc 12 are provided, and two target heads and two venturi pumps are arranged in the mixing cylinder. When the first venturi pump 13 delivers new powder into the mixing cylinder, the new powder hits the first target head 131 to achieve crushing of the new powder. When the second venturi pump 14 delivers coarse powder into the mixing cylinder, the coarse powder hits the second target head 141 to achieve crushing of the coarse powder. After the two powders are mixed in the mixing cylinder, they enter the separation disc 12 together with the airflow. The principle of the separation disc 12 is similar to that of a cyclone separator. The airflow and powder rotate in the disc. The large particles of powder have a large centrifugal force and run along the edge of the disc. The finer powder is easily sucked away by the exhaust pipe in the middle of the disc. A middle circular hole is opened in the middle of the separation disc, and the middle circular hole is connected to the exhaust pipe. The exhaust pipe is then connected to the cyclone separator or other powder collecting equipment behind for collection. The powder rotating along the side wall of the disc will enter the coarse powder pipe, which is connected to the second Venturi pump. Driven by the high-pressure gas of the second Venturi pump, it enters the mixing conveying pipe, and then is ejected at a very high speed and directly hits the second rigid target head. The gas and powder will continue to move forward and enter the disc classifier together with the airflow and powder hit by the first target head.

[0003] The defects of the target jet mill are: the classification effect is not good enough, and the production is difficult to operate and control. In particular, the adjustment of the particle size of the product is not strong enough. For example, if the diameter of the disc is fixed, the particle size of the product needs to be adjusted, and the only way to adjust it is by adjusting the air intake, and the range of this adjustment is very limited, so the range of particle size that can be adjusted is very narrow. Summary of the invention

[0004] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art, to provide a target airflow mill and a powder making method, and to solve the technical problems of narrow particle size adjustment range and insufficient particle size adjustment force in the powder making process of the traditional target airflow mill.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] First aspect:

[0007] Provided is a target-type jet mill, comprising

[0008] A cylindrical barrel, wherein a grading chamber, a powder inlet chamber and a powder crushing chamber are arranged in sequence from top to bottom, a fine powder channel and a coarse powder channel are provided on the grading chamber, and the fine powder channel is connected to an exhaust system;

[0009] A powder classifier is installed in the classification chamber, the powder outlet of the powder classifier is connected to the fine powder channel, and the powder classifier is suitable for classifying the powder in the classification chamber and sending the separated fine powder out of the fine powder channel;

[0010] A powder supply device, which is connected to the powder feeding chamber and is suitable for feeding powder into the powder feeding chamber;

[0011] At least one powder nozzle and a target head, wherein the target head is installed in the powder crushing chamber, the powder nozzle is installed on the barrel of the powder crushing chamber, the powder nozzle inlet is connected to the first Venturi powder pump, the powder nozzle outlet faces the target head, and the first Venturi powder pump and the coarse powder channel are connected to a powder return pipe.

[0012] Furthermore, the number of the powder nozzles and the number of the target heads are both two.

[0013] Furthermore, the classification chamber and the powder feeding chamber are both cylindrical chambers.

[0014] Furthermore, the powder classifier and the fine powder channel are both located at the top center of the classification chamber;

[0015] The fine powder channel is opened at the center of the top of the classification chamber, and the coarse powder channel is opened at the side wall of the top of the classification chamber.

[0016] Furthermore, the powder supply device includes a powder inlet pipe and a second Venturi powder pump, the powder inlet pipe is tangentially arranged on the cylinder, and the second Venturi powder pump delivers new powder into the powder inlet chamber through the powder inlet pipe, so that the new powder rotates circumferentially in the powder inlet chamber.

[0017] Furthermore, the powder classifier is an impeller classifier.

[0018] Furthermore, the powder supply device adopts a screw feeder.

[0019] Furthermore, the powder supply device includes

[0020] A powder inlet cylinder and a second Venturi powder pump, wherein the outlet of the powder inlet cylinder is tangentially connected to the cylinder body, the second Venturi powder pump is connected to the powder inlet cylinder, and a target head is arranged in the powder inlet cylinder;

[0021] When the second Venturi powder pump delivers new powder into the powder inlet tube, the new powder collides with the target head, so that the new powder is broken and then tangentially input into the powder inlet chamber.

[0022] Second aspect:

[0023] Provided is a powder making method, which adopts the above-mentioned target air flow mill, including: new powder is fed into a powder feeding chamber through a powder feeding device, the new powder enters a classification chamber upwardly under the action of a new powder exhaust system, the powder classifier discharges the separated fine powder from the fine powder channel, the remaining coarse powder is sucked into a first venturi powder pump through a powder return pipe, and is carried by the high-pressure airflow sprayed from a powder nozzle and ejected to collide with a target head, so that the powder is crushed, the crushed powder enters the classification chamber upwardly again for powder classification, the fine powder that meets the requirements is sucked away, and the coarse powder is returned to the powder nozzle for collision again.

[0024] Furthermore, new powder enters the powder inlet chamber through a tangentially arranged powder inlet pipe, driving the new powder to rotate circumferentially in the powder inlet chamber. The rotation direction of the new powder in the cylinder is opposite to the rotation direction of the impeller in the powder classifier.

[0025] The beneficial effects of the present invention are:

[0026] The powder classifier can control the particle size of the crushed powder and perform selective control within a large particle size range. Fine powder that meets the set requirements is discharged from the fine powder channel. While the fine powder is discharged and collected in time, the coarse powder is collected and processed centrally. The coarse powder enters the second Venturi pump through the coarse powder channel and is crushed again, thereby improving the powder crushing efficiency and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention is further described below in conjunction with the accompanying drawings.

[0028] Figure 1 This is a schematic diagram of a traditional disc target jet mill;

[0029] Figure 2 It is a schematic diagram of a target-type air jet mill (single target head) of the present invention;

[0030] Figure 3 It is a schematic diagram of a target-type air jet mill (double target head) of the present invention;

[0031] Figure 4 It is a schematic diagram of the target jet mill with powder introduced into the powder barrel;

[0032] in,

[0033] 2. Cylinder, 21. Fine powder channel, 22. Coarse powder channel;

[0034] 3. powder classifier, 31. motor, 32. powder classifying impeller;

[0035] 41. a first venturi powder pump, 42. a second venturi powder pump;

[0036] 5. Target head;

[0037] 6. Powder inlet pipe. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The present application provides a target-type airflow mill, which is described in detail below. It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments of the present application. In the following embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0040] In order to solve the technical problems of narrow particle size adjustment range and insufficient particle size adjustment force in the prior art target-type jet mill during the powder making process, an embodiment of the present application provides a target-type jet mill, which is described in detail below.

[0041] like Figure 2 As shown, a target jet mill comprises

[0042] A cylindrical barrel 2, wherein a grading chamber, a powder inlet chamber and a powder crushing chamber are sequentially arranged in the barrel 2 from top to bottom, a fine powder channel 21 and a coarse powder channel 22 are arranged on the grading chamber, and the fine powder channel 21 is connected to an exhaust system;

[0043] A powder classifier 3 is installed in the classification chamber, and a powder outlet of the powder classifier 3 is connected to the fine powder channel 21. The powder classifier 3 is suitable for classifying the powder in the classification chamber and sending the separated fine powder out from the fine powder channel 21;

[0044] A powder supply device, which is connected to the powder feeding chamber and is suitable for feeding powder into the powder feeding chamber;

[0045] A powder nozzle and a target head 5, wherein the target head 5 is installed in the powder crushing chamber, the powder nozzle is installed on the barrel 2 of the powder crushing chamber, the inlet of the powder nozzle is connected to the first Venturi powder pump 41, the outlet of the powder nozzle faces the target head 5, and the first Venturi powder pump 41 and the coarse powder channel 22 are connected to a return powder pipe.

[0046] In this embodiment, the powder classifier 3 adopts an impeller classifier, which includes a motor 31 and a powder classifying impeller. The powder classifying impeller is located at the entrance of the fine powder channel 21. The motor 31 drives the powder classifying impeller 32 to rotate in the classifying chamber. The fine powder can pass through the powder classifying impeller 32 and enter the fine powder channel. The coarse powder is blocked outside due to the large centrifugal force. The coarse powder is finally sucked away by the negative pressure of the coarse powder channel 22 on one side.

[0047] like Figure 2 As shown, in this embodiment, the number of the powder nozzle and the target head 5 are both one, the powder nozzle is connected to the bottom of the pulverizing chamber, and the target head 5 is located above the powder nozzle.

[0048] like Figure 3 As shown, there are two powder nozzles and two target heads 5, the two powder nozzles are symmetrically arranged on the barrel 2, and the two target heads 5 are symmetrically arranged in the powder crushing chamber.

[0049] In this embodiment, a spray head is installed at the inner end of the powder spray pipe.

[0050] Specifically, as an optional implementation in this embodiment, Figure 2 As shown, the classification chamber and the powder feeding chamber are both cylindrical chambers.

[0051] Specifically, as an optional implementation in this embodiment, Figure 2 As shown, the powder classifier 3 and the fine powder channel 21 are both located at the top center of the classification chamber;

[0052] The fine powder channel 21 is opened at the center of the top of the classification chamber, and the coarse powder channel 22 is opened at the side wall of the top of the classification chamber.

[0053] The cylindrical chamber helps the powder to rotate in the chamber. The powder rotation can separate the coarse powder to the inner wall of the chamber, and the fine powder can be retained in the center, which is convenient for the separation of coarse and fine powders.

[0054] Specifically, as an optional implementation in this embodiment, Figure 2 As shown, the powder supply device includes a powder inlet pipe and a second Venturi powder pump 42. The powder inlet pipe is tangentially arranged on the barrel 2. The second Venturi powder pump 42 delivers new powder into the powder inlet chamber through the powder inlet pipe, so that the new powder rotates circumferentially in the powder inlet chamber.

[0055] As another embodiment of the powder supply device, the powder supply device adopts a screw feeder. A predetermined amount of powder can be slowly added into the powder inlet chamber through the second venturi powder pump 42.

[0056] The powder supply device adopts the second Venturi powder pump 42, which has the advantages that new powder can be sprayed tangentially into the powder feeding chamber, and the powder rotates tangentially in the powder feeding chamber, thereby preliminarily achieving the separation of coarse powder.

[0057] The powder inlet of the second Venturi powder pump 42 is equipped with a feed hopper. During operation, a predetermined amount of new powder is loaded into the feed hopper and then pumped into the cylinder 2 at a required speed through the second Venturi powder pump 42 .

[0058] like Figure 4 As shown, another embodiment of the powder supply device;

[0059] The powder supply device comprises

[0060] A powder inlet tube 6 and a second Venturi powder pump 42, wherein the outlet of the powder inlet tube 6 is tangentially connected to the cylinder body, the second Venturi powder pump 42 is connected to the powder inlet tube 6, and a target head 5 is arranged in the powder inlet tube 6;

[0061] When the second Venturi powder pump 42 delivers new powder into the powder inlet tube 6, the new powder collides with the target head 5, so that the new powder is broken and then tangentially input into the powder inlet chamber.

[0062] The powder feeding device of this embodiment can first crush the new powder, and then send the crushed powder into the powder feeding chamber, and then the powder after the collision with the target head 5 of the coarse powder at the bottom will go upward into the classification chamber. This powder feeding device on the air flow grinding belt can improve the powder making efficiency. Figure 2 In the jet mill, the new powder is not crushed when it enters the cylinder, and can only be crushed by a target head 5 in the powder crushing chamber, and the powder making efficiency is relatively low.

[0063] Conventional disc target jet mill, see Figure 1 The fine powder in the separation disc is directly pumped away, and the particle size of the pumped fine powder is not controlled in advance, which leads to the uncontrolled particle size of the coarse powder flowing back, which ultimately affects the powder classification of the target jet mill during the powder making process. Figure 2 and Figure 3 As shown, an impeller powder classifier 3 is directly installed on the cylinder 2. The particle size of the crushed powder separated is controlled by adjusting the rotation speed of the powder classification impeller 32. Selective control can be performed within a large particle size range. Fine powder that meets the particle size requirements is extracted through the fine powder channel 21, and then the remaining coarse powder is collected and processed centrally, and is pumped into the cylinder 2 through the second Venturi powder pump 42 for target crushing.

[0064] Target jet mill is suitable for crushing materials with high flexibility.

[0065] The working process of the target-type airflow mill of the present invention is as follows: new powder is pumped into the cylinder 2 through the second Venturi powder pump 42. When the new powder is pumped into the cylinder 2 through the powder inlet pipe, the new powder rotates tangentially, which can drive the powder in the cylinder 2 to rotate, so that the coarse powder is separated outward. The motor 31 controls the rotation of the powder classification impeller 32. The speed of the powder classification impeller 32 is controlled by the motor 31, and the fine powder that meets the particle size requirements is discharged through the subdivision channel. The remaining coarse powder enters the first Venturi powder pump 41 through the powder return pipe, and the coarse powder is collided with the target head 5 by the first Venturi powder pump 41 to achieve re-crushing of the coarse powder.

[0066] An embodiment of the present application provides a flour making method, which is described in detail below.

[0067] A powder making method adopts the above-mentioned target airflow mill, including: new powder is sent into the powder feeding chamber through the powder feeding device, and the new powder enters the classification chamber upward under the action of the new powder exhaust system, the powder classifier 3 discharges the separated fine powder from the fine powder channel 21, and the remaining coarse powder is sent to each first venturi powder pump 41 and the powder nozzle through the powder return pipe, the high-pressure airflow ejected from the powder nozzle carries the coarse powder and collides with the target head 5, so that the powder is crushed, and the crushed powder enters the classification chamber again upward for powder classification, the fine powder that meets the requirements is extracted, and the coarse powder is returned to the powder nozzle for collision again.

[0068] Specifically, as an optional implementation in this embodiment, Figure 2 and Figure 3 As shown, new powder enters the powder inlet chamber through the tangentially arranged powder inlet pipe, driving the new powder to rotate circumferentially in the powder inlet chamber, and the rotation direction of the new powder in the cylinder 2 is opposite to the rotation direction of the impeller in the powder classifier 3. Because the rotating powder-carrying airflow and the counter-rotating impeller make the separation of fine powder more selective.

[0069] The various devices selected in this application (components whose specific structures are not described) are all universal standard parts or components known to technical personnel in this field, and their structures and principles can be known to technical personnel through technical manuals or through conventional experimental methods.

[0070] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0072] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0073] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0074] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0075] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A target jet mill, characterized in that: include A cylindrical barrel (2), wherein a classification chamber, a powder inlet chamber and a powder crushing chamber are sequentially arranged in the barrel (2) from top to bottom, a fine powder channel (21) and a coarse powder channel (22) are arranged on the classification chamber, and the fine powder channel (21) is connected to an exhaust system; A powder classifier (3) is installed in the classification chamber, and a powder outlet of the powder classifier (3) is connected to the fine powder channel (21). The powder classifier (3) is suitable for classifying the powder in the classification chamber and sending the separated fine powder out from the fine powder channel (21); A powder supply device, which is connected to the powder feeding chamber and is suitable for feeding powder into the powder feeding chamber; At least one powder nozzle and a target head (5), wherein the target head (5) is installed in the powder crushing chamber, the powder nozzle is installed on the barrel (2) of the powder crushing chamber, the inlet of the powder nozzle is connected to a first venturi powder pump (41), the outlet of the powder nozzle faces the target head (5), and the first venturi powder pump (41) and the coarse powder channel (22) are connected to a powder return pipe.

2. The target jet mill according to claim 1, characterized in that: The number of the powder spray tube and the number of the target head (5) are both two.

3. The target jet mill according to claim 1, characterized in that: The classification chamber and the powder feeding chamber are both cylindrical chambers.

4. The target jet mill according to claim 3, characterized in that: The powder classifier (3) and the fine powder channel (21) are both located at the top center of the classification chamber; The fine powder channel (21) is opened at the center of the top of the classification chamber, and the coarse powder channel (22) is opened at the side wall of the top of the classification chamber.

5. The target jet mill according to claim 3, characterized in that: The powder supply device comprises a powder inlet pipe and a second Venturi powder pump (42), wherein the powder inlet pipe is tangentially arranged on the barrel (2), and the second Venturi powder pump (42) delivers new powder into the powder inlet chamber through the powder inlet pipe, so that the new powder rotates circumferentially in the powder inlet chamber.

6. The target jet mill according to claim 3, characterized in that: The powder classifier (3) is an impeller classifier.

7. The target jet mill according to claim 3, characterized in that: The powder supply device adopts a screw feeder.

8. The target jet mill according to claim 3, characterized in that: The powder supply device comprises A powder inlet barrel (6) and a second Venturi powder pump (42), wherein the outlet of the powder inlet barrel (6) is tangentially connected to the barrel body, the second Venturi powder pump (42) is connected to the powder inlet barrel (6), and a target head (5) is arranged in the powder inlet barrel (6); When the second Venturi powder pump (42) delivers new powder into the powder inlet tube (6), the new powder collides with the target head (5), causing the new powder to break and then be tangentially fed into the powder inlet chamber.

9. A flour making method, characterized in that: The target airflow mill according to any one of claims 1 to 7 comprises: new powder is fed into a powder feeding chamber through a powder feeding device, the new powder enters a grading chamber upwardly under the action of a new powder exhaust system, the powder classifier (3) discharges the separated fine powder from a fine powder channel (21), the remaining coarse powder is sucked into a first venturi powder pump (41) through a powder return pipe, and is carried by a high-pressure airflow ejected from a powder nozzle to collide with a target head (5), thereby crushing the powder, and the crushed powder enters the grading chamber upwardly again for powder classification, the fine powder that meets the requirements is sucked away, and the coarse powder is returned to the powder nozzle for collision again.

10. The flour making method according to claim 9, characterized in that: New powder enters the powder inlet chamber through a tangentially arranged powder inlet pipe, driving the new powder to rotate circumferentially in the powder inlet chamber. The rotation direction of the new powder in the cylinder (2) is opposite to the rotation direction of the impeller in the powder classifier (3).

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