Self-circulation negative pressure system of centrifugal machine
By designing the centrifuge self-circulation negative pressure system, the negative pressure cavity environment is used to attract and reintroduce dust, the problems of dust leakage and dust during discharge of the centrifuge dehydrator are solved, and the effect of environmental cleaning and resource conservation is achieved.
Patent Information
- Application Number
- CN202421607422.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-09
- Publication Date
- 2025-05-30
- Estimated Expiration
- 2034-07-09
AI Technical Summary
When discharging the material, the centrifugal dehydrator is prone to cause dust leakage and dust leakage, resulting in operating environment pollution and resource loss.
A centrifuge self-circulation negative pressure system is designed. By setting up a discharge groove between the plate feeder and the vertical centrifugal dewaterer, a discharge sealing cover is set between the vertical centrifugal dewaterer and the tape conveyor, and the discharge sealing cover is connected through the powder feeding tube to form a negative pressure cavity environment, attracting the surrounding dust and reintroducing it into the production system through the powder feeding tube.
It effectively curbs the dispersion of dust, ensures the cleanliness of the surrounding environment, has great environmental protection significance, saves resource loss, and improves the safety of the working environment.
Smart Images
Figure CN222918836U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of centrifugal dehydration equipment, in particular to a self-circulating negative pressure system for a centrifuge. Background Art
[0002] In coal preparation plants, centrifugal dehydrators are essential equipment for removing moisture from fine-grained products. They can use the centrifugal force generated by high-speed rotation to throw out the moisture contained in the materials, reduce the moisture content of the products in the coal preparation plant, and play an important role in the process of transporting products. Their operating effect will directly affect the benefits of the coal preparation plant. However, during the use of centrifugal dehydrators, various faults and areas for improvement will occur. Most of the improvements at home and abroad are dedicated to extending their stable operating time and improving their working efficiency, and there are few improvements in other aspects. However, there is still a defect phenomenon that is rarely mentioned during the use of centrifugal dehydrators. When the centrifugal dehydrator discharges materials onto the belt conveyor, due to the non-sealed conveying method, during this transfer process, the materials are all in a free state and scattered, and there will be leakage and / or dust flying of relatively fine dust particles, resulting in serious dust diffusion, polluting the surrounding working environment, and at the same time increasing resource losses. Summary of the Utility Model
[0003] The utility model provides a self-circulating negative pressure system for a centrifuge to solve the problems of dust leakage and dust flying during the discharging of centrifugal dehydrators in the prior art, resulting in environmental pollution of the working environment and resource losses.
[0004] Specifically, the utility model provides a self-circulating negative pressure system for a centrifuge, including: a plate feeder, a vertical centrifugal dehydrator, and a belt conveyor; a rotating drum is arranged inside the vertical centrifugal dehydrator; a feeding chute is arranged at the discharging end of the plate feeder, and the feeding chute is connected to the feeding trough at the top of the vertical centrifugal dehydrator. The feeding trough is rotationally connected and communicated with the top end of the rotating drum; the bottom end of the rotating drum is rotationally connected to the discharging cylinder of the vertical centrifugal dehydrator; the discharging cylinder is connected with a discharging airtight cover, and the discharging port of the discharging airtight cover is correspondingly arranged opposite to the feeding end of the belt conveyor; a powder feeding port is arranged on the side wall of the discharging airtight cover, the powder feeding port is connected with a lower powder feeding pipe, a powder inlet is arranged on the side wall of the feeding chute, the powder inlet is connected with an upper powder feeding pipe, and the lower powder feeding pipe and the upper powder feeding pipe are communicated through a flange-type flexible connection structure.
[0005] Optionally, the discharging airtight cover is an inverted conical structure with a larger upper part and a smaller lower part; a one-way valve facing the powder inlet is arranged between the lower powder feeding pipe and the upper powder feeding pipe.
[0006] Optionally, a baffle column is arranged in the discharging airtight cover, and an annular material falling channel is formed between the baffle column and the inner wall of the discharging airtight cover.
[0007] Optionally, a support frame is provided inside the discharge airtight cover, and the material blocking column is installed on the support frame in a height-adjustable manner through a screw-nut mechanism.
[0008] Optionally, the material blocking column is arranged at a position close to the discharge port of the discharge airtight cover, and the material blocking column is below the powder feeding port.
[0009] Optionally, the material blocking column has an upper-large and lower-small structure, or the material blocking column is a cylindrical structure.
[0010] Optionally, the outlet diameter of the blanking cylinder is greater than or equal to the top diameter of the material blocking column.
[0011] Optionally, an air supplement and blowing tube is connected to the side wall of the upper powder feeding pipe, and a one-way valve facing the upper powder feeding pipe is provided on the air supplement and blowing tube.
[0012] Optionally, the included angle between the air supplement and blowing tube and the vertically arranged upper powder feeding pipe is 15-35°.
[0013] The self-circulating negative pressure system of the centrifuge provided by the present utility model forms a blanking chute between the plate feeder and the vertical centrifugal dewatering machine, an airtight discharge cover is arranged between the vertical centrifugal dewatering machine and the belt conveyor, and the blanking chute and the airtight discharge cover are connected through a powder feeding pipe. Thus, when the material falls in the airtight discharge cover, a negative pressure cavity environment is temporarily formed in the inner cavity of the airtight discharge cover, and through the self-suction pressure generated by the internal and external air pressure difference, the diffused dust, floating dust, etc. around are sucked into the inner cavity of the airtight discharge cover. Then, the dust is sent into the blanking chute through the upper powder feeding pipe and the lower powder feeding pipe, and is driven by the wet material to re-enter the production system, achieving the purpose of self-circulating negative pressure dust absorption, solving the problem of no effective containment measures for dust scattering during the transfer process, curbing the scattering of dust, ensuring the cleanliness of the surrounding environment, having great environmental protection significance, also ensuring the occupational health and safety of employees, and the material circulating into the production system also saves the loss of resources, having economic value, and is applicable to the centrifugal dehydration and drying process after washing of raw materials such as various minerals, textiles (knitted fabrics), clothing, printing and dyeing, food, hardware, chemicals, etc., and latex products.
[0014] The airtight discharge cover also forms an annular material falling channel in its inner cavity through the material blocking column, so that a negative pressure effect is formed at the center of the material column, enabling the material to be subjected to an inward pressure, and the dust in the material is easily concentrated inward, not easily scattered to form floating dust, nor easily scattered and leaked everywhere, which can further effectively improve the working environment and more effectively control the falling effect of the falling material during the conveying and transfer process of the material. Description of the Drawings
[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0016] Figure 1 It is a schematic structural diagram of a self-circulating negative pressure system of a centrifuge provided by an embodiment of the present invention;
[0017] Figure 2 It is a schematic structural diagram of a discharge airtight cover provided by an embodiment of the present invention;
[0018] Figure 3 It is a schematic diagram of the connection relationship between the upper powder feeding pipe and the air supplement and blowing pipe provided by an embodiment of the present invention.
[0019] Explanation of reference numerals:
[0020] 1 - Plate feeder, 2 - Vertical centrifugal dehydrator, 3 - Belt conveyor, 4 - Feeding chute, 5 - Feeding tank, 6 - Feeding cylinder, 7 - Discharge airtight cover, 8 - Lower powder feeding pipe, 9 - Upper powder feeding pipe, 41 - Powder inlet, 71 - Discharge port, 72 - Powder feeding port, 73 - Baffle post, 74 - Support frame, 91 - Air supplement and blowing pipe. Specific embodiments
[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following clearly and completely describes the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts also belong to the scope of protection of the present invention.
[0022] Such as Figure 1As shown in the figure, a self-circulating negative pressure system of a centrifuge provided by the utility model includes: a plate feeder 1, a vertical centrifugal dewatering machine 2 and a belt conveyor 3; a rotating drum is arranged inside the vertical centrifugal dewatering machine 2; a feeding chute 4 is arranged at the discharging end of the plate feeder 1, and the feeding chute 4 is connected to a feeding trough 5 at the top of the vertical centrifugal dewatering machine 2, and the feeding trough 5 is rotatably connected and communicated with the top end of the rotating drum; the bottom end of the rotating drum is rotatably connected to a discharging cylinder 6 of the vertical centrifugal dewatering machine 2; the discharging cylinder 6 is connected with a discharging airtight cover 7, and the discharging port 71 of the discharging airtight cover 7 is arranged corresponding to the feeding end of the belt conveyor 3; a powder feeding port 72 is arranged on the side wall of the discharging airtight cover 7, the powder feeding port 72 is connected with a lower powder feeding pipe 8, a powder inlet 41 is arranged on the side wall of the feeding chute 4, and the powder inlet 41 is connected with an upper powder feeding pipe 9, and the lower powder feeding pipe 8 and the upper powder feeding pipe 9 are communicated through a flange flexible connection structure.
[0023] The vertical centrifugal dewatering machine 2 adopted in the utility model is a commonly used device in the field, and the rotating drum therein is also a conventional technology. Therefore, the structures of the vertical centrifugal dewatering machine 2 and the rotating drum are not specially limited herein. The flange flexible connection structure between the lower powder feeding pipe 8 and the upper powder feeding pipe 9 facilitates the maintenance of the powder feeding pipes. The discharging cylinder 6 and the discharging airtight cover 7 can be relatively fixedly assembled or hinged to each other. Specifically, different assembly methods can be selected according to actual situations. However, it should be noted that the connection between the discharging cylinder 6 and the discharging airtight cover 7 should be effectively sealed to facilitate the formation of a negative pressure chamber in the inner cavity of the discharging airtight cover 7.
[0024] The plate feeder 1 conveys the wet materials to its discharging end, then sends the wet materials to the feeding chute 4, enters the feeding trough 5 at the top of the vertical centrifugal dewatering machine 2 through the feeding chute 4, and then enters the rotating drum of the vertical centrifugal dewatering machine 2. After centrifugal dewatering in the rotating drum, the dry materials enter the discharging airtight cover 7 through the discharging cylinder 6, and then fall from the discharging port 71 and fall onto the feeding end of the corresponding belt conveyor 3 arranged. The dried dry materials are sent to the next process by the belt conveyor 3. When the dry materials fall through the discharging airtight cover 7, the dry materials fall from the inner cavity of the discharging airtight cover 7 onto the belt conveyor 3 and are immediately sent away by the belt of the belt conveyor 3, resulting in a relatively lower pressure at the position of the flowing path of the dry materials compared to the pressure of the external air, and temporarily forming a negative pressure cavity environment in the inner cavity of the discharging airtight cover 7. When the dry materials fall on the belt conveyor 3, the impact causes relatively fine dust particles to be splashed and escape, and through the self-suction pressure generated by the internal and external air pressure difference, the dust, dust and other diffused around are sucked into the inner cavity of the discharging airtight cover 7.
[0025] With a similar principle, while the rotary drum discharges materials, the feeding chute 4 conveys wet materials to the feeding trough 5. During the falling process of the wet materials, a similar negative pressure environment is formed in the feeding chute 4, thereby causing an air flow towards the powder inlet 41 to be formed in the upper powder conveying pipe 9 connected thereto. The air pressure in the upper powder conveying pipe 9 decreases, further affecting the air pressure in the lower powder conveying pipe 8, thus sucking dust in the suction discharge closed hood 7, etc. The dust enters the lower powder conveying pipe 8 through the powder feeding port 72 and is sent to the powder inlet 41 along with the air flow, and is driven by the wet materials to re-enter the vertical centrifugal dewatering machine 2, achieving the purpose of self-circulating negative pressure dust absorption, solving the problem of dust scattering during transportation without effective containment measures, curbing the dust scattering, ensuring the cleanliness of the surrounding environment, having great environmental protection significance, and also ensuring the occupational health and safety of employees. The material recycling into the production system also saves resource consumption and has economic value.
[0026] As Figure 1 shown, optionally, the discharge closed hood 7 is an inverted conical structure with a larger upper part and a smaller lower part; a one-way valve (routinely arranged, not shown in the drawings) towards the powder inlet is provided between the lower powder conveying pipe 8 and the upper powder conveying pipe 9. The structure with a larger upper part and a smaller lower part is set. Compared with the open shape, it is easier to form a negative pressure effect in the inner cavity of the discharge closed hood 7 after the material falls, and the relatively more convergent and retracted outlet 71 shape is also more convenient for sucking the dust around. The one-way valve is beneficial for guiding the air flow direction and preventing the negative pressure environment in the discharge closed hood 7 from being broken.
[0027] As Figure 2 shown, optionally, a baffle column 73 is provided in the discharge closed hood 7, and an annular material falling channel is formed between the baffle column 73 and the inner wall of the discharge closed hood 7. By setting the baffle column 73 in the discharge closed hood 7 and forming an annular material falling channel, a material column with a thinner middle and denser periphery is formed when the material falls. There is less material at the center position of the material column. After the internal air falls with the material, the pressure at the center position is relatively low, and it is easy to form a slightly negative pressure area at the center position of the material column, thereby causing the external air to move towards the material column, causing the material to be subjected to an inward pressure. The dust in the material is easy to concentrate inward and is not easy to scatter and form dust, and the material column shrinks inward and is not easy to spill out everywhere, which can further effectively improve the working environment and more effectively control the falling effect of the material during the transportation and transfer process of the material.
[0028] As Figure 2As shown, optionally, a support frame 74 is provided inside the discharge closed hood 7, and the baffle column 73 is installed on the support frame 74 with adjustable height through a screw-nut mechanism. The support frame 74 is fixed to the inner wall of the discharge closed hood 7. An internal thread hole is provided on the support frame 74, and a corresponding external thread section is provided on the screw rod. The screw rod and the internal thread hole form a threaded fit, so that the position of the baffle column 73 can be adjusted up and down. Compared with the way where the position of the baffle column 73 is fixed, by using the cooperation of the support frame 74 and the screw-nut mechanism, the position of the baffle column 73 can be conveniently adjusted up and down according to the characteristics of the actual material, so that the size and shape of the annular material dropping channel can be adjusted, increasing the operation flexibility of the system.
[0029] Optionally, the baffle column 73 is arranged at a position close to the discharge port 71 of the discharge closed hood 7, and the baffle column 73 is below the powder feeding port 72. The baffle column 73 is at the position of the discharge port 71 and below the powder feeding port 72, and its blocking and anti-escaping effects on the falling material are more beneficial to the conveying and transfer processes of the material, and it is more convenient to control the falling effect of the material.
[0030] Optionally, the baffle column 73 has a structure with a larger upper part and a smaller lower part, or the baffle column 73 is a cylindrical structure. The shape structure of the baffle column 73 is regular, which is beneficial to ensuring the uniformity of the falling material. It is preferred that the baffle column 73 has a structure with a larger upper part and a smaller lower part, such as regular or irregular structures such as an inverted cone, an inverted trapezoid or a funnel shape. Most preferably, it is an inverted trapezoid, which can make the side wall of the baffle column 73 parallel to the inner wall of the discharge closed hood 7. It can ensure that the annular material dropping channel is relatively symmetrical and evenly distributed while ensuring the centralized falling of the material, ensuring the uniformity of the falling material and facilitating the formation of a central negative pressure area.
[0031] Optionally, the outlet diameter of the blanking cylinder 6 is greater than or equal to the top diameter of the baffle column 73. The volume of the baffle column 73 should not be too large, otherwise it is easy to cause congestion in the discharge of the blanking cylinder 6 or slow down the falling speed of the material. And falling the material at a faster speed is more beneficial to forming a negative pressure area at the central position of the falling material, and the anti-escaping effect of the material is better.
[0032] To further enhance the negative pressure effect in the lower powder feeding pipe 8 and the upper powder feeding pipe 9, such as Figure 3As shown, optionally, an air supplement and blowing assist pipe 91 is connected to the side wall of the upward powder feeding pipe 9, and a one-way valve facing the upward powder feeding pipe 9 is provided on the air supplement and blowing assist pipe 91. Preferably, the included angle between the air supplement and blowing assist pipe 91 and the vertically arranged upward powder feeding pipe 9 is 15 - 35°. Through the air supplement and blowing assist pipe 91, gas can be intermittently and in small amounts blown into the upward powder feeding pipe 9, preferably nitrogen. Moreover, there is an included angle between the air supplement and blowing assist pipe 91 and the upward powder feeding pipe 9, and preferably the included angle faces the direction of the powder inlet 41, so that the gas enters the material discharging chute 4 along the pipeline. After blowing, a transient negative pressure will be formed in the upward powder feeding pipe 9, thereby sucking the gas in the downward powder feeding pipe 8, strengthening the negative pressure effect in the downward powder feeding pipe 8, and further strengthening the negative pressure condition and negative pressure suction effect of the discharging airtight cover 7, enabling it to suck more escaping dust through the powder feeding port 72 and the discharging port 71, ensuring the use effect of the discharging airtight cover 7.
[0033] It should be noted that the arrows without attached reference numerals in the drawings indicate the flow direction of the materials.
[0034] The following further elaborates on the present utility model in detail with specific embodiments.
[0035] Embodiment 1
[0036] Taking the coal centrifugal dehydration operation in the coal washing system as an example, the working process of the centrifuge self - circulating negative pressure system is as follows: The plate feeder 1 conveys wet coal with a water content of about 4% to its discharging end, and then sends the wet coal to the material discharging chute 4. It enters the feeding chute 5 at the top of the vertical centrifuge 2 through the material discharging chute 4, and then enters the rotating drum of the vertical centrifuge 2. After centrifugal dehydration in the rotating drum, the dry coal enters the discharging airtight cover 7 through the discharging cylinder 6, and then falls from the discharging port 71 to the feeding end of the correspondingly arranged belt conveyor 3. The dried dry coal is sent to the next process by the belt conveyor 3.
[0037] When the dry coal falls through the discharge closed cover 7, it falls from the inner cavity of the discharge closed cover 7 onto the belt conveyor 3, and is then conveyed away by the belt of the belt conveyor 3, resulting in the pressure of the dry coal flowing through the path being lower than the pressure of the outside air, temporarily forming a negative pressure cavity environment in the inner cavity of the discharge closed cover 7. When the dry coal falls on the belt conveyor 3, the impact causes the relatively fine coal powder particles to be splashed and escape, and the self-priming pressure generated by the pressure difference between the inside and outside air sucks the coal powder and dust diffused around into the inner cavity of the discharge closed cover 7. While the drum is unloading, the unloading chute 4 transports wet coal to the feeding chute 5. In the process of the wet coal falling, a similar negative pressure environment is formed in the unloading chute 4, so that an airflow toward the powder inlet 41 is formed in the upper powder delivery pipe 9 connected thereto. The air pressure in the upper powder delivery pipe 9 is reduced, which further affects the air pressure in the lower powder delivery pipe 8, thereby sucking and unloading the coal powder in the closed cover 7. The coal powder enters the lower powder delivery pipe 8 through the powder delivery port 72 and is sent to the powder inlet 41 with the air flow, and is driven by the wet coal to re-enter the vertical centrifugal dehydrator 2, and the adsorbed and recovered coal powder is returned to the coal washing production system, so as to achieve the purpose of self-circulating negative pressure dust absorption.
[0038] Example 2
[0039] On the basis of the above-mentioned embodiment, the present embodiment also includes: a material blocking column 73 is set in the unloading closed cover 7 to form an annular material dropping channel, and the position of the material blocking column 73 is adjusted up and down by the support frame 74 and the screw nut mechanism, so that the size and shape of the annular material dropping channel can be adjusted. The dry coal falls through the blocking effect of the material blocking column 73, forming a material column that is thin in the middle and dense around. There is less dry coal in the center of the material column. After the internal air falls with the dry coal, the pressure at the center is relatively low, and it is easy to form a slightly negative pressure area at the center of the material column, thereby causing the external air to move toward the material column, so that the dry coal is subjected to inward pressure, and the coal powder in the dry coal is easy to concentrate inward, and it is not easy to float out and form dust. The material column shrinks inward and is not easy to fall and leak everywhere, which can further effectively improve the working environment and more effectively control the landing effect of the falling material during the transportation and transfer process of the dry coal.
[0040] Example 3
[0041] On the basis of the above embodiment, this embodiment further includes: an air-supplementing blowing-assisting pipe 91 is connected to the side wall of the upper powder delivery pipe 9, and the angle between the air-supplementing blowing-assisting pipe 91 and the upper powder delivery pipe 9 is 15-35°, and the angle is preferably toward the powder inlet 41. Through the air-supplementing blowing-assisting pipe 91, a small amount of gas can be intermittently blown into the upper powder delivery pipe 9, so that the gas enters the discharge chute 4 along the pipeline, and a short negative pressure is formed in the upper powder delivery pipe 9 after the blowing, thereby sucking the gas in the lower powder delivery pipe 8, strengthening the negative pressure effect in the lower powder delivery pipe 8, and further strengthening the negative pressure condition and negative pressure suction effect of the discharge closed cover 7.
[0042] It should be noted that in the present utility model, the detailed structures of some devices are not described in detail, but are prior arts known to those skilled in the art, so they will not be elaborated herein. Additionally, the parts not involved in this device are the same as or can be implemented using prior arts.
[0043] It should be noted that those skilled in the art can also make partial modification designs to the above system under the guidance of the present utility model. For example, overflow / nitrogen pipelines are also provided on the devices in the system; pumps, pressure sensors, flow meters, or temperature sensors are provided on the conveying pipelines inside the system between different units or devices and equipment, and different valves are also provided, such as pressure relief valves, pressure regulating valves, safety valves, pneumatic valves, etc., which are used to regulate and stabilize the pressure of the entire system, and the opening degree of the valves can also be adjusted to regulate the material flow rate in the pipeline.
[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model, rather than to limit it; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present utility model.
Claims
1. A centrifuge self-circulating negative pressure system, characterized in that: include: A plate feeder, a vertical centrifugal dehydrator and a belt conveyor; a rotating drum is provided inside the vertical centrifugal dehydrator; The unloading end of the plate feeder is provided with a unloading trough, the unloading trough is connected to the feeding trough at the top of the vertical centrifugal dehydrator, and the feeding trough is rotatably connected and communicated with the top of the rotating drum; The bottom end of the rotating drum is rotatably connected to the discharge drum of the vertical centrifugal dehydrator; the discharge drum is connected to a discharge closed cover, and the discharge port of the discharge closed cover is arranged corresponding to the feed end of the belt conveyor; A powder delivery port is provided on the side wall of the unloading closed cover, and the powder delivery port is connected to a lower powder delivery pipe. A powder inlet is provided on the side wall of the unloading trough, and the powder inlet is connected to an upper powder delivery pipe. The lower powder delivery pipe is connected to the upper powder delivery pipe through a flange-type soft connection structure.
2. The centrifuge self-circulating negative pressure system according to claim 1, characterized in that: The discharge closed cover is an inverted cone structure with a larger upper portion and a smaller lower portion; a one-way valve toward the powder inlet is provided between the lower powder delivery pipe and the upper powder delivery pipe.
3. The centrifuge self-circulating negative pressure system according to claim 1, characterized in that: A material-blocking column is arranged in the unloading closed cover, and an annular material-dropping channel is formed between the material-blocking column and the inner wall of the unloading closed cover.
4. The centrifuge self-circulating negative pressure system according to claim 3, characterized in that: A support frame is arranged in the unloading closed cover, and the material blocking column is installed on the support frame in a height-adjustable manner through a screw rod and nut mechanism.
5. The centrifuge self-circulating negative pressure system according to claim 3, characterized in that: The material blocking column is arranged at a position close to the material discharge port of the discharge sealing cover, and the material blocking column is below the powder feeding port.
6. The centrifuge self-circulating negative pressure system according to claim 3, characterized in that: The material blocking column has a structure that is larger at the top and smaller at the bottom, or the material blocking column has a cylindrical structure.
7. The centrifuge self-circulating negative pressure system according to claim 3, characterized in that: The outlet diameter of the lower barrel is greater than or equal to the top diameter of the material blocking column.
8. The centrifuge self-circulating negative pressure system according to any one of claims 1 to 7, characterized in that: An air-supplementing and blowing-assisting pipe is connected to the side wall of the upper powder-feeding pipe, and a one-way valve facing the upper powder-feeding pipe is arranged on the air-supplementing and blowing-assisting pipe.
9. The centrifuge self-circulating negative pressure system according to claim 8, characterized in that: The angle between the air supply and blowing-assisting pipe and the upper powder delivery pipe in the vertical direction is 15-35°.