Powder feeding equipment
By designing the stirring device and feeder in the material box, the discontinuity of feeding and equipment blockage caused by poor fluidity of powder materials is solved, and the stable continuous operation and efficient treatment effect of wastewater and waste gas treatment is achieved.
Patent Information
- Application Number
- CN202421519468.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-01
- Publication Date
- 2025-07-18
- Estimated Expiration
- 2034-07-01
AI Technical Summary
Due to poor fluidity, existing powder materials are prone to accumulation and moisture, resulting in discontinuous feeding, resulting in waste or poor treatment effect, and existing equipment is prone to blockage, affecting the wastewater and waste gas treatment effect.
A powder feeding equipment including a material box, agitator and a feeder is designed, equipped with a mixing shaft, a turner and a screw feeder, combined with a level gauge and a vibrator to achieve continuous agitation and quantitative control of the material to prevent stacking and blockage.
The continuous and uniform feeding of powder materials is achieved, the equipment is blocked, the efficiency and cost-effectiveness of wastewater and waste gas treatment are improved, and the stable operation is ensured.
Smart Images
Figure CN223118156U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the field of waste gas and wastewater treatment, and particularly relates to a powder feeding device. Background Art
[0002] With the continuous strengthening of environmental protection efforts, the treatment requirements for various wastewaters and waste gases are becoming increasingly strict. Using ordinary chemical reagents for physical and chemical reactions to treat pollutants can no longer meet the increasingly strict environmental protection requirements. Therefore, various powder materials for wastewater and waste gas treatment have been developed, which have excellent performance in the process of treating pollutants in waste gas and wastewater and have been widely used. Although powder materials have small particle size, large specific surface area, high surface activity, and strong pertinence in treating specific pollutants, and are increasingly popular in the market, due to their powder characteristics, their fluidity is relatively poor, resulting in easy material accumulation and more susceptibility to moisture, making it impossible to achieve precise feeding; since the cost of these powder materials is relatively high, if the feeding is not continuous or the feeding amount is too small, the expected treatment effect cannot be achieved, and if the feeding amount is too large, it will cause waste and reduce the cost performance advantage of the new powder materials. Therefore, the corresponding research and development of powder material feeding equipment is of great practical significance for engineering and technical personnel in related fields and market needs. Content of the Utility Model
[0003] The utility model provides a powder feeding device that can prevent blockage, accelerate the dynamic flow of materials, control the feeding amount, and operate continuously and stably for a long period, which is used for the continuous normal operation process of adding powder functional materials in the process of wastewater and waste gas treatment.
[0004] To achieve the above object, the utility model provides a powder feeding device, which includes a material box, a stirring device, and a feeder. A stirring device is arranged in the material box, and a feeder is arranged below the material box. The feeder includes a turnover device and a screw feeder. The inlet of the turnover device is connected to the discharge port of the material box, and the outlet of the turnover device is connected to the inlet of the screw feeder.
[0005] The top of the material box is provided with an opening, and the bottom is a discharge port. The upper part of the inner cavity of the material box is a cylindrical storage cavity, and the lower part is an inverted conical discharge cavity. A level gauge for monitoring the height of the material in the discharge cavity and a vibrator for vibrating the outer wall of the discharge cavity are installed on the side wall of the material box in the area where the discharge cavity is located.
[0006] Further, the level gauge is arranged at the position of the discharge chamber of the material bin. When the material in the material bin is less, it can provide a warning signal of no material. Of course, multiple level gauges can also be arranged vertically in the material bin to provide high-level warning signals, medium-level warning signals, and low-level warning signals, so as to realize remote monitoring and warning prompts of the material level; the vibrator is arranged in the discharge chamber of the material bin, and the vibrator and the level gauge are symmetrically distributed around the vertical central axis of the discharge chamber of the material bin, so as to reduce the potential impact on the level gauge when the vibrator vibrates and operates. The regular vibration of the vibrator can effectively prevent the phenomenon that the powder material is affected by static electricity and other reasons, such as bridging, which affects normal discharging; in this embodiment, the included angle between the conical surface of the discharge chamber of the material bin and the vertical central axis of the material bin is less than 30°, preferably 20-25°.
[0007] In this embodiment, the stirring device includes a first driving mechanism for driving the stirring shaft to rotate, a stirring shaft installed in the material bin, and stirring blades installed on the stirring shaft. The stirring shaft is arranged in the middle of the inner cavity of the material bin and coincides with the central axis of the material bin. The stirring blades include multiple sets of horizontal connecting rod groups arranged along the axial direction of the stirring shaft and vertical connecting rods installed at the ends of the horizontal connecting rod groups far from the stirring shaft. Multiple sets of horizontal connecting rod groups are arranged within the range of the discharge chamber. Each set of horizontal connecting rod groups includes multiple horizontal connecting rods evenly arranged around the stirring shaft on the same horizontal plane. The horizontal connecting rods are arranged perpendicular to the stirring shaft. The vertical connecting rods are arranged parallel to the inner wall of the material bin, and the distance between the vertical connecting rods and the inner wall of the material bin matches the vibration amplitude of the vibrator. A top plate is installed on the top opening of the material bin. A feeding port is provided on one side of the top plate. A cover plate for sealing the feeding port is hinged on the top plate. The first driving mechanism is installed on the top plate.
[0008] Further, the stirring shaft extends into the material bin from the outer top end of the material bin. At least one set of horizontal connecting rod groups, preferably more than three sets of horizontal connecting rod groups, are arranged from top to bottom in the area of the discharge chamber of the material bin. The horizontal connecting rods in adjacent horizontal connecting rod groups can be arranged in the same vertical plane or staggered at an angle of 0-90°, preferably evenly arranged in parallel. At least one vertical connecting rod is provided at the end of the horizontal connecting rod far from the stirring shaft. The horizontal connecting rods and the vertical connecting rods can continuously and evenly divide the powder material in the material bin, prevent the powder material from depositing, sticking and caking, and piling up and bridging, keep the powder material with relatively poor fluidity in a continuous stirring state, promote uniform and continuous feeding, and at the same time, the vertical connecting rod is close to the inner wall of the material bin, which can scrape the material falling from the inner wall of the material bin.
[0009] In this embodiment, the screw feeder includes a feeding pipe, a feeding screw installed in the feeding pipe, and a second driving mechanism for driving the feeding screw to rotate. The feeding pipe is provided with a feeding port. The agitator includes a guiding cylinder and agitating blades installed in the guiding cylinder. The agitating blades are connected to the second driving mechanism through a transmission mechanism to realize linkage with the feeding screw. The guiding cylinder is vertically arranged, the bottom of the guiding cylinder is fixed on the feeding port of the feeding pipe, and the material box is connected to the top of the guiding cylinder through a detachable connector.
[0010] With the above structure, the agitator is arranged above the feeding spiral section of the screw feeder. The agitator can continuously cut and agitate the powder material in the guiding cylinder, preventing the powder material from depositing, sticking and caking, and piling up and bridging. The powder material with relatively poor fluidity is always in a continuous agitation state, preventing the upper part of the screw feeder from being emptied due to material bridging and other reasons, and promoting uniform and continuous feeding into the feeding spiral of the screw feeder.
[0011] In this embodiment, the detachable connector includes a male flange arranged outside the discharge port of the material box and a female flange arranged outside the feeding port of the guiding cylinder. The male flange and the female flange are fixed and locked through a hoop, and the material box and the guiding cylinder are connected through a hoop. When the agitator needs to be overhauled, the material box and the guiding cylinder can be conveniently separated by using the hoop connection.
[0012] In this embodiment, a dust-proof cover is arranged outside the outlet of the feeding pipe. The dust-proof cover can prevent the dust at the outlet of the screw feeder from being scattered by the wind, affecting the on-site production and operation environment, and at the same time avoiding the escape and waste of the powder material.
[0013] In this embodiment, the second driving mechanism includes a motor and a speed reducer. The transmission mechanism includes a first transmission gear, a second transmission gear and a rotating shaft. The output end of the motor is connected to the input end of the speed reducer, the output end of the speed reducer is coaxially connected to the feeding screw, and a second transmission gear is also coaxially installed on the output end of the speed reducer. The first transmission gear meshes with the second transmission gear, the first transmission gear is coaxially fixed on the rotating shaft, and the agitating blades are driven to rotate through the rotating shaft. The motor adopts a variable-frequency motor, and the rotation speed of the screw propeller is controlled by the motor to realize quantitative control of feeding and avoid material waste.
[0014] Compared with the prior art, for some functional powder materials, due to their relatively poor powder fluidity, the existing feeding equipment often presents a vicious cycle of material accumulation, relatively extended residence time after accumulation, and more prone to moisture accumulation and blockage. This leads to unsmooth feeding, immobile material accumulation, equipment idling, and even complete blockage. This device not only has a stirring device in the feed hopper, but also a stirrer is arranged between the discharge port of the feed hopper and the feed inlet of the screw feeder. Through the cooperation of the stirring device, the stirrer and the screw feeder, it can stably prevent the powder material from bridging and agglomerating due to static electricity and other reasons, resulting in equipment idling and inability to discharge normally, avoiding the ineffective operation of the wastewater treatment system and improving the effective utilization rate of the wastewater treatment device.
[0015] In summary, the utility model has a simple structure, low processing and manufacturing cost, simple control, can continuously discharge materials normally and stably, and improve the wastewater treatment effect. Brief Description of the Drawings
[0016] Figure 1 It is a schematic structural diagram of the utility model.
[0017] In the drawings, 1, dust cover; 2, screw feeder; 3, conveying pipe; 4, guide cylinder; 5, level gauge; 6, vertical connecting rod; 7, feed hopper; 8, stirring shaft; 9, first driving mechanism; 10, cover plate; 11, feeding port; 12, horizontal connecting rod; 13, vibrator; 14, hoop; 15, stirring blade; 16, first transmission gear; 17, second transmission gear; 18, reducer; 19, motor; 20, feeder; 21, stirring device; 22, stirrer. Detailed Embodiments
[0018] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.
[0019] In addition, the technical solutions between the various embodiments of the present utility model can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions conflicts with each other or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.
[0020] Such as Figure 1As shown in the figure, the utility model provides a powder feeding device, which includes a material box 7, a stirring device 21 and a feeder 20. A stirring device 21 is arranged in the material box 7. The top of the material box 7 is provided with an opening, and the bottom is provided with a discharge port. The upper part of the inner cavity of the material box 7 is a cylindrical storage cavity, and the lower part is an inverted conical discharge cavity. The included angle between the conical surface of the discharge cavity and the vertical central axis of the material box 7 is less than 30°, preferably 20 - 25°. A level gauge 5 for monitoring the height of the material in the discharge cavity and a vibrator 13 for vibrating the outer wall of the discharge cavity of the material box 7 are installed on the side wall of the material box 7 in the area where the discharge cavity is located. The level gauge 5 is arranged at the position of the discharge cavity of the material box 7. When the material in the material box 7 is less, it can provide a warning signal of no material. Of course, multiple level gauges 5 can also be arranged vertically in the material box 7 to provide high-level warning signals, medium-level warning signals and low-level warning signals, so as to realize remote monitoring and warning prompts of the material level; The vibrator 13 is arranged in the discharge cavity of the material box 7. The vibrator 13 and the level gauge 5 are symmetrically distributed around the vertical central axis of the discharge cavity of the material box 7, so as to reduce the potential influence on the level gauge 5 when the vibrator 13 vibrates and operates. The regular vibration of the vibrator 13 can effectively prevent the phenomenon that the powder material is affected by static electricity and other reasons such as bridging and affects the normal discharge;
[0021] The feeder 20 includes a stirrer 22 and a screw feeder 2. The inlet of the stirrer 22 is connected to the discharge port of the material box 7, and the outlet of the stirrer 22 is connected to the inlet of the screw feeder 2;
[0022] Further, the stirring device 21 includes a first driving mechanism 9 for driving the rotation of the stirring shaft 8, a stirring shaft 8 installed in the material box 7, and stirring blades installed on the stirring shaft 8. The stirring shaft 8 is arranged in the middle of the inner cavity of the material box 7 and coincides with the central axis of the material box 7. The stirring blades include multiple sets of horizontal connecting rod groups arranged along the axial direction of the stirring shaft 8 and vertical connecting rods 6 installed at one end of the horizontal connecting rod group away from the stirring shaft 8. Multiple sets of horizontal connecting rod groups are arranged within the range of the discharge cavity. Each set of horizontal connecting rod groups includes multiple horizontal connecting rods 12 that are evenly arranged around the stirring shaft 8 on the same horizontal plane. The horizontal connecting rods 12 are arranged perpendicular to the stirring shaft 8. The vertical connecting rods 6 are arranged parallel to the inner wall of the material box 7. The distance between the vertical connecting rods 6 and the inner wall of the material box 7 matches the vibration amplitude of the vibrator 13. A top plate is installed on the opening of the material box 7. A feeding port 11 is provided on one side of the top plate. A cover plate 10 that can seal the feeding port 11 is hinged on the top plate. The first driving mechanism 9 is installed on the top plate. The stirring shaft 8 extends into the material box 7 from the outer top end of the material box 7. At least one set of horizontal connecting rod groups is provided on the stirring shaft 8 from top to bottom in the area of the discharge cavity of the material box 7. In this embodiment, it is preferably more than three sets of horizontal connecting rod groups. The horizontal connecting rods 12 in adjacent horizontal connecting rod groups can be arranged in the same vertical plane or can be staggered at an angle of 0 to 90°, preferably arranged in parallel and evenly. At least one vertical connecting rod 6 is provided at one end of the horizontal connecting rod 12 away from the stirring shaft 8. The horizontal connecting rods 12 and the vertical connecting rods 6 can continuously and evenly divide the powder material in the material box 7, prevent the powder material from depositing, sticking and caking, and piling up and bridging, keep the powder material with relatively poor fluidity in a continuous stirring state, promote uniform and continuous feeding, and at the same time, the vertical connecting rods 6 are close to the inner wall of the material box 7, which can scrape the material falling on the inner wall of the material box 7.
[0023] In this embodiment, the screw feeder 2 includes a feeding pipe 3, a feeding screw installed in the feeding pipe 3, and a second driving mechanism for driving the rotation of the feeding screw. The feeding pipe 3 is provided with a feeding port. The turning device 22 includes a guiding cylinder 4 and turning blades 15 installed in the guiding cylinder 4. The turning blades 15 are connected to the second driving mechanism through a transmission mechanism to realize linkage with the feeding screw. The guiding cylinder 4 is arranged vertically. The bottom of the guiding cylinder 4 is fixed on the feeding port of the feeding pipe 3. The material box 7 is connected to the top of the guiding cylinder 4 through a detachable connecting piece. The turning device 22 is arranged above the feeding spiral section of the screw feeder 2. The turning device 22 can continuously cut and turn the powder material in the guiding cylinder 4, prevent the powder material from depositing, sticking and caking, and piling up and bridging, make the powder material with relatively poor fluidity always in a continuous stirring state, prevent the upper part of the screw feeder 2 from being blocked and bridged, etc., resulting in the idling of the screw feeder 2, and promote uniform and continuous feeding into the feeding spiral of the screw feeder 2.
[0024] In this embodiment, the detachable connecting member includes a sub-flange disposed outside the discharge port of the feed bin 7 and a mother flange disposed outside the feed port of the material guiding cylinder 4. The sub-flange and the mother flange are fixedly locked by a hoop 14, and the feed bin 7 and the material guiding cylinder 4 are connected by the hoop 14. When using the hoop 14 to connect the feed bin 7 and the material guiding cylinder 4, it is convenient to separate the feed bin 7 from the material guiding cylinder 4 when the agitator needs to be overhauled.
[0025] In this embodiment, a dust-proof cover 1 is provided outside the outlet of the conveying pipe 3. The dust-proof cover 1 can prevent the dust at the outlet of the screw feeder 2 from being scattered by the wind, which affects the on-site production and operation environment, and at the same time avoids the escape and waste of powder materials.
[0026] In this embodiment, the second driving mechanism includes a motor 19 and a speed reducer 18. The transmission mechanism includes a first transmission gear 16, a second transmission gear 17 and a rotating shaft. The output end of the motor 19 is connected to the input end of the speed reducer 18. The output end of the speed reducer 18 is coaxially connected to the conveying screw 2. A second transmission gear 17 is also coaxially installed on the output end of the speed reducer 18. The first transmission gear 16 meshes with the second transmission gear 17. The first transmission gear 16 is coaxially fixed on the rotating shaft, and the turning vane 15 is driven to rotate by the rotating shaft. The motor 19 is a variable-frequency motor, and the rotation speed of the screw propeller is controlled by the frequency conversion of the motor 19 to achieve quantitative control of the feeding and avoid material waste.
[0027] The operation process of the present utility model is as follows:
[0028] Pour the powder material into the feed bin 7, start the first driving mechanism 9, the stirring device 21 runs first, and at the same time the vibrator 13 is energized and runs regularly. The level gauge 5 displays the presence or absence of materials and provides a no-material warning signal to remind to replenish the materials in the feed bin 7 in time. The first driving mechanism 9 continuously runs to drive the stirring shaft 8, the cross connecting rod 12, and the vertical connecting rod 6 to run synchronously. The cross connecting rod 12 and the vertical connecting rod 6 can continuously stir the powder material in the feed bin to prevent the material in the feed bin from being air-supported and accumulated, keep the material flowing dynamically, and ensure smooth feeding.
[0029] Then, start the second driving mechanism. The motor 19 drives the feeder 20 to operate. The speed of the motor 19 is controlled by frequency conversion. After further deceleration by the speed reducer 18, it drives the second transmission gear 17 and the screw feeder 2 to operate, evenly pushing the powder material to the discharge end of the screw feeder. Under the protection of the dust-proof cover 1, the powder material will not escape into the surrounding environment. The powder material then discharges from the lower outlet of the dust-proof cover 1 and enters the wastewater, participating in the physicochemical process of wastewater treatment. At the same time, the second transmission gear 17 drives the first transmission gear 16 to operate, and the first transmission gear 16 drives the turning blades 15 to operate. The turning blades 15 continuously turn and stir the powder material above the screw feeder 2, preventing the powder material from bridging and accumulating, and promoting the uniform and continuous entry of the powder material into the screw feeder 2, and evenly and continuously discharging it towards the outlet end. The whole set of powder feeding equipment operates continuously and stably, evenly, continuously and stably adding the powder material for wastewater treatment into the wastewater, completing the physicochemical reaction process of wastewater treatment, and achieving the purpose of wastewater treatment.
[0030] Example 1:
[0031] This example uses a powder feeding equipment, which specifically includes the following steps:
[0032] (1) Pour the flocculant powder material into the feed box.
[0033] (2) Start the frequency conversion motor. The frequency conversion motor drives the screw feeder and the agitator to operate. Start the vibrator and the level gauge. Start the first driving mechanism and the stirring device, and send the flocculant powder material into the wastewater reaction tank.
[0034] (3) Continuously operate for 168 hours. During the operation, no faults such as blockage occur, and the operation is continuous, stable and normal.
[0035] (4) After detection, the treatment efficiency of suspended solids in the wastewater reaches more than 99%, which can effectively ensure that the suspended solid pollutants in the wastewater are treated qualified and meet the treatment standard.
[0036] Example 2:
[0037] This example uses a powder feeding equipment, which specifically includes the following steps:
[0038] (1) Pour the mercury adsorption and removal powder material into the feed box.
[0039] (2) Start the frequency conversion motor. The frequency conversion motor drives the screw feeder and the agitator to operate. Start the vibrator and the level gauge. Start the first driving mechanism and the stirring device, and send the mercury adsorption and removal powder material into the wastewater reaction tank.
[0040] (3) Continuously operate for 168 hours. During the operation, no faults such as blockage occur, and the operation is continuous, stable and normal.
[0041] (4) After detection, the mercury removal efficiency in the wastewater reaches over 95%, reducing the mercury pollutant content in the wastewater to the required target index, and it can be used for further in-depth mercury removal treatment.
[0042] Example 3:
[0043] This example uses a powder feeding device, which specifically includes the following steps:
[0044] (1) Pour the thallium-adsorbing powder material into the feed box.
[0045] (2) Start the variable-frequency motor, which drives the spiral feeder and the agitator to operate. Start the vibrator and the level gauge, and start the first driving mechanism and the stirring device to send the thallium-adsorbing powder material into the wastewater reaction tank.
[0046] (3) Operate continuously for 168 hours. During the operation, no failures such as blockages occur, and the operation is continuous, stable, and normal.
[0047] (4) After detection, the thallium content in the wastewater can stably reach below 0.005 mg / L, reducing the thallium pollutant content in the wastewater to the required target index and meeting the treatment standard.
[0048] The above are only the preferred embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. All equivalent structural transformations made under the concept of the present utility model by using the content of the specification and drawings of the present utility model, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present utility model.
Claims
1. A powder feeding device, characterized in that: It includes a feed bin (7), a stirring device (21) and a feeder (20). A stirring device (21) is arranged in the feed bin (7), and a feeder (20) is arranged below the feed bin (7). The feeder (20) includes a turner (22) and a screw feeder (2). The inlet of the turner (22) is connected to the discharge port of the feed bin (7), and the outlet of the turner (22) is connected to the inlet of the screw feeder (2). The top of the feed bin (7) is provided with an opening and the bottom is a discharge port. The upper part of the inner cavity of the feed bin (7) is a cylindrical storage cavity, and the lower part is an inverted conical discharge cavity. A level gauge (5) for monitoring the height of the material in the discharge cavity and a vibrator (13) for vibrating the outer wall of the discharge cavity are installed on the side wall of the feed bin (7) in the area where the discharge cavity is located.
2. The powder feeding device according to claim 1, characterized in that: The stirring device (21) includes a first driving mechanism (9) for driving the stirring shaft (8) to rotate, a stirring shaft (8) installed in the feed bin (7), and stirring blades installed on the stirring shaft (8). The stirring shaft (8) is arranged in the middle of the inner cavity of the feed bin (7) and coincides with the central axis of the feed bin (7). The stirring blades include multiple groups of horizontal connecting rod groups arranged along the axial direction of the stirring shaft (8) and vertical connecting rods (6) installed at one end of the horizontal connecting rod groups far from the stirring shaft (8). Multiple groups of horizontal connecting rod groups are arranged within the range where the discharge cavity is located. Each group of horizontal connecting rod groups includes multiple horizontal connecting rods (12) evenly arranged around the stirring shaft (8) on the same horizontal plane. The horizontal connecting rods (12) are arranged perpendicular to the stirring shaft (8), and the vertical connecting rods (6) are arranged parallel to the inner wall of the feed bin (7). The distance between the vertical connecting rods (6) and the inner wall of the feed bin (7) matches the vibration amplitude of the vibrator (13).
3. The powder feeding device according to claim 2, characterized in that: A top plate is installed on the opening at the top of the feed bin (7). A feeding port (11) is provided on one side of the top plate, and a cover plate (10) for sealing the feeding port (11) is hinged on the top plate. The first driving mechanism (9) is installed on the top plate.
4. A powder feeding device according to any one of claims 1 to 3, characterized in that: The screw feeder (2) includes a conveying pipe (3), a conveying screw installed in the conveying pipe (3), and a second driving mechanism for driving the conveying screw to rotate. The conveying pipe (3) is provided with a feeding port. The turner (22) includes a guide cylinder (4) and turning blades (15) installed in the guide cylinder (4). The turning blades (15) are connected to the second driving mechanism through a transmission mechanism to realize linkage with the conveying screw. The guide cylinder (4) is arranged vertically, and the bottom of the guide cylinder (4) is fixed on the feeding port of the conveying pipe (3). The feed bin (7) is connected to the top of the guide cylinder (4) through a detachable connecting piece.
5. A powder feeding device according to claim 4, characterized in that: The detachable connecting piece includes a sub-flange arranged outside the discharge port of the feed bin (7) and a mother-flange arranged outside the feeding port of the guide cylinder (4). The sub-flange and the mother-flange are fixed and locked by a hoop (14).
6. A powder feeding device according to claim 4, characterized in that: A dust cover (1) is arranged outside the outlet of the conveying pipe (3).
7. A powder feeding device according to claim 4, characterized in that: The second driving mechanism includes a motor (19) and a speed reducer (18). The transmission mechanism includes a first transmission gear (16), a second transmission gear (17) and a rotating shaft. The output end of the motor (19) is connected to the input end of the speed reducer (18). The output end of the speed reducer (18) is coaxially connected to the feeding screw. A second transmission gear (17) is also coaxially installed on the output end of the speed reducer (18). The first transmission gear (16) meshes with the second transmission gear (17). The first transmission gear (16) is coaxially fixed on the rotating shaft. The turning blade (15) is driven to rotate by the rotating shaft.