Backflow structure of jet mill

Abstract

A shell of the jet mill is of a tubular structure, the lower section of the shell is a milling chamber, a nozzle is arranged on the side wall of the milling chamber, a feeding pipe is arranged on the side wall of the milling chamber in a penetrating mode, a discharging opening of the feeding pipe is located above a smashing area, and a grading impeller is arranged at the top of the shell. A conical pipe is coaxially arranged below the grading impeller, the cone top of the conical pipe faces upwards, the inner hole diameter of the cone top is larger than the outer diameter of the grading impeller, and an annular interval is formed between the cone bottom and the inner wall of the shell. A backflow pipe of a funnel structure is coaxially arranged below the conical pipe and located above the grinding chamber, the inner wall of the upper end of the backflow pipe is connected with the inner wall of the shell, the lower end of the backflow pipe is located above the smashing area, a plurality of strip-shaped notches are formed in the lower end of the backflow pipe in a circumferential array mode, and inclined plates are arranged between the adjacent strip-shaped notches. According to the scheme, the one-time crushing qualification rate and the crushing efficiency of materials can be effectively improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of the internal structure of a fluid energy mill, and particularly relates to a fluid energy mill reflux structure. Background Art

[0002] A fluid energy mill is a pulverizing device that uses a Laval nozzle to eject a high-speed air stream, and uses the strong multiphase turbulent flow field formed by the air stream to make the materials therein collide and rub against each other, so as to pulverize the material particles. The nozzle is usually installed on the side wall of the pulverizing chamber, and a classification impeller is arranged above the pulverizing chamber. The pulverized materials are sucked upward by negative pressure. The materials with qualified particle sizes enter the inside of the classification impeller and then are discharged. The materials with large particle sizes will be thrown to the side wall of the device under the action of the centrifugal force generated when the classification impeller rotates. Most of the thrown materials will fall along the side wall and then be discharged from the discharge port below. Only a small part of the thrown materials can flow back to the turbulent flow field and be pulverized again. The materials discharged from the discharge port below need to be collected and then sent into the pulverizing chamber again for pulverization. The pulverization efficiency of such a device is low, there are many large-particle materials discharged from the discharge port, and the qualified rate of one-time pulverization is low. Content of the Utility Model

[0003] In order to solve the deficiencies of the prior art, the utility model provides a fluid energy mill reflux structure, which can effectively improve the qualified rate of one-time pulverization of materials and the pulverization efficiency.

[0004] In order to achieve the purpose of the utility model, the following scheme is proposed:

[0005] A fluid energy mill reflux structure, the housing of the fluid energy mill is in a tubular structure, the lower section thereof is a grinding chamber, a nozzle is arranged on the side wall of the grinding chamber, a feed pipe penetrates through the side wall of the grinding chamber, and the discharge port of the feed pipe is located above the pulverizing area. A classification impeller is arranged at the top of the housing.

[0006] A conical tube is coaxially arranged below the classification impeller, its cone top faces upward, the inner diameter of the cone top is larger than the outer diameter of the classification impeller, and there is an annular interval between the cone bottom and the inner wall of the housing.

[0007] A reflux pipe with a funnel structure is coaxially arranged below the conical tube. The reflux pipe is located above the grinding chamber. The inner wall of the upper end of the reflux pipe is connected to the inner wall of the housing. The lower end of the reflux pipe is located above the pulverizing area. Multiple strip-shaped notches are arranged in a circumferential array at the lower end of the reflux pipe, and there are inclined plates between adjacent strip-shaped notches.

[0008] The beneficial effect of the utility model is that the large-particle materials thrown out by the classification impeller can smoothly enter the pulverizing area again, reducing the large-particle materials discharged from the lower end of the housing, and avoiding repeatedly putting the large-particle materials into the grinding chamber from the feed pipe, thereby improving the qualified rate of one-time pulverization of materials and the pulverization efficiency. Description of the Drawings

[0009] The accompanying drawings described herein are only for illustrating selected embodiments, not all possible implementation schemes, and are not intended to limit the scope of the present utility model.

[0010] Figure 1 It shows a schematic diagram of the external structure of the present application.

[0011] Figure 2 It shows a schematic diagram of the internal structure of the present application.

[0012] Figure 3 It shows a schematic diagram of the structure of the reflux pipe.

[0013] Markings in the figure: grinding chamber - 11, nozzle - 12, feed pipe - 13, classification impeller - 14, discharge pipe - 15, conical pipe - 2, rib - 21, reflux pipe - 3, strip - shaped notch - 31, inclined plate - 32, sliding groove - 321. Detailed implementation manners

[0014] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the following will describe the implementation manners of the present utility model in detail with reference to the accompanying drawings. However, the embodiments described herein are only a part of the embodiments of the present utility model, not all of the embodiments.

[0015] As Figures 1 to 3 shown, a reflux structure of a jet mill, the housing of the jet mill is in a tubular structure, the lower end thereof is a grinding chamber 11, the side wall of the grinding chamber is provided with a nozzle 12, the side wall of the grinding chamber is penetrated by a feed pipe 13, the discharge port of the feed pipe 13 is located above the pulverization area, and the pulverization area refers to the turbulent flow field formed by the air flow ejected from the nozzle 12. The top of the housing is provided with a classification impeller 14.

[0016] Specifically, as Figure 2 shown, a conical pipe 2 is coaxially provided inside the housing corresponding to the lower part of the classification impeller 14, its conical top faces upward, the inner diameter of the conical top is larger than the outer diameter of the classification impeller 14, and there is an annular interval between the conical bottom and the inner wall of the housing.

[0017] Specifically, as Figure 2 shown, a reflux pipe 3 in a funnel structure is coaxially provided below the conical pipe 2. The reflux pipe 3 is located above the grinding chamber 11. The inner wall of the upper end of the reflux pipe 3 is connected to the inner wall of the housing. The lower end of the reflux pipe 3 is located above the pulverization area, specifically, it means that the lower end of the reflux pipe 3 is located above the turbulent flow field formed by the air flow ejected from the nozzle. A plurality of strip - shaped notches 31 are arranged in a circumferential array at the lower end of the reflux pipe 3, and there is an inclined plate 32 between adjacent strip - shaped notches 31.

[0018] During operation, materials are added into the interior of the grinding chamber 11 through the feed pipe 13. After being crushed in the crushing area, the materials automatically rise under the drive of the negative-pressure air flow, and the negative-pressure air flow is provided by the discharge pipe 15 above the classification impeller 14. The conical pipe 2 can more centrally guide the crushed materials upward. And because the inner diameter of the conical top of the conical pipe 2 is larger than the outer diameter of the classification impeller 14, the crushed materials can smoothly move from the side of the classification impeller 14 into the interior, making the flow path of the materials more consistent and concentrated during classification. During classification, the materials with qualified particle sizes enter the interior of the classification impeller 14 and then are discharged from the discharge pipe 15. The materials with larger particle sizes are thrown by the blades of the classification impeller 14 to the surroundings. Since most of the rising negative-pressure air flow is concentrated in the conical pipe 2, there is a relatively small rising air flow between the outer side of the conical pipe 2 and the housing. Coupled with the fact that the particle sizes of the thrown materials are relatively large, the thrown materials can smoothly fall from the annular gap between the conical bottom of the conical pipe 2 and the inner wall of the housing. After the materials fall from the annular gap, they will automatically fall into the reflux pipe 3. Because a strip-shaped notch 31 is provided at the lower end of the reflux pipe 3, negative pressure will form a rising air flow at the strip-shaped notch 31 to facilitate driving the crushed materials to rise. Affected by the air flow at the strip-shaped notch 31, the large-particle materials that automatically fall into the reflux pipe 3 will be pushed by the air flow onto the inclined plate 32. Because the air flow in the space close to the top surface of the inclined plate 32 is weak, the large-particle materials can smoothly fall downward along the inclined plate 32 into the crushing area and then participate in the crushing process again. In this way, the large-particle materials discharged from the lower end of the housing can be effectively reduced, thereby improving the crushing efficiency of the materials.

[0019] Preferably, as Figure 3 shown, the top surface of the inclined plate 32 has a chute 321, and the chute 321 is arranged along the length direction of the inclined plate 32 to facilitate gathering the large-particle materials and enabling the large-particle materials that fall into the reflux pipe 3 to smoothly enter the crushing area.

[0020] Preferably, as Figure 1 、 Figure 2 shown, the housing of the air classifier is provided with four mutually spliced sections from top to bottom, which are used to arrange the classification impeller 14, the conical pipe 2, the reflux pipe 3, and the grinding chamber 11 from top to bottom in sequence. This design splits the housing into a spliced multi-section structure to facilitate manufacturing, assembly, and subsequent maintenance. Specifically, the sections of the housing are connected by screws.

[0021] Preferably, the conical pipe 2 and the reflux pipe 3 are made of plastic to reduce the overall weight and facilitate molding at the same time.

[0022] Preferably, as Figure 2 shown, the outer wall of the conical pipe 2 is connected to the housing by a plurality of ribs 21 arranged at intervals.

[0023] The above are only the preferred embodiments of the present utility model, and do not represent the only or limit the present utility model. Those skilled in the art should understand that various changes or equivalent substitutions made to the present utility model without departing from the scope of the present utility model all fall within the scope of protection of the present utility model.

Claims

1. An air classifier mill reflux structure, the housing of the air classifier mill is in a tubular structure, the lower section thereof is a grinding chamber (11), the side wall of the grinding chamber is provided with nozzles (12), a feed pipe (13) penetrates through the side wall of the grinding chamber, the discharge port of the feed pipe (13) is located above the pulverizing area, and a classification impeller (14) is arranged at the top of the housing, characterized in that ； A conical tube (2) is coaxially arranged below the classification impeller (14), with its cone tip facing upward. The inner diameter of the cone tip is larger than the outer diameter of the classification impeller (14), and there is an annular gap between the cone bottom and the inner wall of the housing. A return pipe (3) with a funnel structure is coaxially arranged below the conical tube (2). The return pipe (3) is located above the grinding chamber (11). The inner wall of the upper end of the return pipe (3) is connected to the inner wall of the housing. The lower end of the return pipe (3) is located above the crushing area. A plurality of strip-shaped notches (31) are arranged in a circumferential array at the lower end of the return pipe (3), and there are inclined plates (32) between adjacent strip-shaped notches (31).

2. The air classifier return structure according to claim 1, wherein The top surface of the inclined plate (32) has a chute (321), and the chute (321) is arranged along the length direction of the inclined plate (32).

3. The air classifier reflux structure according to claim 1, characterized in that, The housing of the air classifier mill is provided with four sections spliced from top to bottom, which are used to arrange the classification impeller (14), the conical tube (2), the return pipe (3) and the grinding chamber (11) in sequence from top to bottom.

4. The airflow mill reflux structure according to claim 1, characterized in that, The conical tube (2) and the return pipe (3) are made of plastic.

5. The air classifier reflux structure according to claim 1, characterized in that The outer wall of the conical tube (2) is connected to the housing through a plurality of ribs (21) arranged at intervals.

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