A recovery device for massaging powder

Abstract

This invention discloses a device for recovering powders such as massage powder, belonging to the field of industrial dust removal and powder recovery technology. The device includes a dust removal unit, a screw conveyor unit, a material sealing unit, and a control unit. The screw conveyor unit has a material sealing unit at its discharge end. The screw blades terminate before the inlet end of the material sealing unit, and the portion of the screw shaft within the material sealing unit is a smooth section without screw blades, where the powder material accumulates and compacts to form a powder plunger sealing barrier. The control unit is configured to respond to a shutdown signal from upstream production equipment, controlling the screw conveyor unit to continue operating for a preset time to discharge residual material from the ash hopper and retain the intact powder plunger to maintain the seal. This invention replaces the mechanical seal with a plunger formed by the powder itself, solving the problem of moisture infiltration during shutdown leading to moisture absorption and deterioration of the recovered powder, and achieving integrated efficient dust collection and sealed recovery.

Description

Technical Field

[0001] This invention relates to the field of industrial dust removal and powder recovery technology, specifically to a device for recovering powders such as massage powder. Background Technology

[0002] In the production and processing of powdered materials such as traditional Chinese medicine powders, food additives, and fine chemical raw materials, processes such as crushing, sieving, mixing, and packaging generate a large amount of fine dust. To control the dust concentration in the workshop environment and meet air pollutant emission standards, dust removal equipment is commonly used in industrial production to purify dust-laden gases. Currently, the mainstream approach in this field is to use bag filters or cartridge dust collectors as the core separation equipment, utilizing the physical interception effect of fiber filter media or membrane filter media to separate and capture dust from the airflow. The captured dust falls into the ash hopper at the bottom of the dust collector under gravity and is then discharged through a discharge device. For the discharge device, rotary valves or gravity flap valves are commonly used, with rotary valves being the most widely applied due to their compact structure and continuous discharge capability.

[0003] However, when using a rotary valve, a gap exists at its connection with the ash hopper. Under negative pressure operation of the dust collector, air from the outside environment can seep into the ash hopper through this gap. When moisture comes into contact with the powder, it easily causes agglomeration, leading to powder bridging within the ash hopper and hindering unloading. Furthermore, the powder absorbs moisture, agglomerates, and may even mold, severely affecting powder quality and rendering it unusable for recycling. In addition, traditional dust collection and unloading equipment often uses synchronous start-stop control. After the production line stops, the negative pressure in the dust collector quickly disappears, leaving the ash hopper and unloading channel completely exposed to the humid environment. Continuous backflow of moisture further exacerbates powder deterioration and loss, making it difficult to meet the actual production requirements for the closed-loop recovery, moisture-proof storage, and continuous and stable unloading of high-value hygroscopic powders such as massage powder. Summary of the Invention

[0004] The technical problem that this invention aims to solve is: In view of the above-mentioned technical problem, the purpose of this invention is to provide a device for recycling powders such as massage powder, so as to solve the problems mentioned in the background art.

[0005] The technical solution adopted by this invention is as follows: A device for recycling powders such as massage powder is proposed, comprising: The dust removal unit includes a dust collector body and a filter assembly disposed within the dust collector body. The lower part of the dust collector body is provided with a dust hopper. The filter assembly is used to separate and capture dust particles from the dust-laden gas and collect the captured dust in the dust hopper. The screw conveyor unit includes an inlet end and an outlet end. The inlet end is connected to the bottom outlet of the ash hopper, and the outlet end of the screw conveyor unit is connected to a material sealing unit. The material sealing unit is configured to allow the powder material pushed by the screw conveyor unit to accumulate and compact therein, forming a powder plunger sealing barrier that blocks the passage of gas. The system includes a control unit, which is communicatively connected to both the dust removal unit and the screw conveyor unit. The control unit is configured to respond to a shutdown signal from the upstream production equipment by controlling the screw conveyor unit to continue operating for a preset time after the dust removal unit stops, so as to discharge the remaining material in the ash hopper and maintain a seal by keeping the intact powder plunger in the material sealing unit.

[0006] Furthermore, the spiral conveying unit includes a housing, a spiral shaft disposed within the housing, and spiral blades. The radial gap between the outer edge of the spiral blades and the inner wall of the housing is 0.10 mm to 0.30 mm, so as to allow the powder to form a shear powder film layer that assists in sealing at the gap.

[0007] Furthermore, the pitch P of the spiral blades gradually decreases along the discharge direction to pre-compact the powder material before it enters the material sealing unit.

[0008] Furthermore, the spiral blades are arranged axially along the spiral shaft, and the termination position of the spiral blades is located before the inlet end of the material sealing unit, so that the spiral shaft portion within the material sealing unit is a bare shaft section without spiral blades.

[0009] Furthermore, the inner diameter of the material sealing unit tapers from the inlet end to the outlet end to apply a gradually increasing radial extrusion force to the powder material as it is pushed axially.

[0010] Furthermore, the dust removal unit also includes a pulse jet cleaning unit disposed on the upper part of the dust collector body, and the filter assembly is a polytetrafluoroethylene membrane filter cartridge; The main body of the dust collector is provided with a dust-laden gas inlet and a clean gas outlet on its sides; The bottom of the dust collector body is connected to the ash hopper.

[0011] Furthermore, the outer side of the ash hopper is provided with an anti-bridging unit, which includes an anti-bridging actuator and an anti-bridging controller. The anti-bridging actuator is intermittently started and stopped by the anti-bridging controller at a preset frequency. The control unit is also communicatively connected to the anti-bridging unit and is configured to: when bridging of powder is detected in the ash hopper, control the anti-bridging actuator to start intermittent operation to destroy the powder arch structure.

[0012] Furthermore, the anti-bridging actuator includes a vibrator and a micro-orifice airflow injector, which are arranged alternately along the circumference of the ash hopper.

[0013] Furthermore, it also includes a discharge port, which is located to the side and below the outlet end of the material sealing unit, and the discharge port is connected to an external receiving box.

[0014] Beneficial effects: By setting a material sealing unit at the discharge end of the screw conveyor unit, the dense powder plunger formed by the accumulation and compaction of powder material in the material sealing unit serves as a sealing barrier. This powder plunger can effectively block external gas from entering the ash hopper through the discharge channel, solving the problem of moisture infiltration caused by the fit gap of the traditional star-shaped discharge valve. This ensures that the recovered powder will not absorb moisture, clump, or become moldy during shutdown, maintaining the original physical properties and recycling value of the powder. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a device for recycling powders such as massage powder, as proposed in an embodiment of the present invention. Figure 2 This is a front view schematic diagram of a powder recovery device for massage powder and other powders according to an embodiment of the present invention; Figure 3 This is a top view schematic diagram of a powder recovery device for massage powder and other powders according to an embodiment of the present invention; Figure 4 for Figure 3 Schematic diagram of the AA section along the middle.

[0016] The components include: 1. Pulse jet cleaning unit; 2. Clean air outlet; 3. Dust collector body; 4. Dust hopper; 5. Anti-bridging actuator; 6. Screw conveyor unit; 7. Drive motor; 8. Anti-bridging controller; 9. Dust-laden gas inlet; 10. Filter assembly; 11. Screw blades; 12. Screw shaft; 13. Support frame; 14. Discharge port; 15. Material sealing unit; and 16. End cover.

[0017] The accompanying drawings are provided to further understand the embodiments and form part of the specification. They are used together with the embodiments for explanation and do not constitute a limitation on the embodiments. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection.

[0019] In the description of the embodiments, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments.

[0020] The production process of massage powder includes grinding, mixing, and sieving of the powder. During these processes, a large amount of fine dust is generated. If effective ventilation and dust removal measures are not taken, the dust will remain suspended in the workshop air for a long time, not only polluting the working environment but also being easily inhaled into the lungs by operators. At the same time, the dust can be recycled and reused. However, in the process of powder material production, the unloading stage of the dust removal device generally suffers from problems such as moisture infiltration due to gaps in the fit, powder agglomeration and bridging, and jamming of the unloading valve, which seriously affects the continuity of unloading and the recycling rate.

[0021] To address the above problems, the present invention provides a device for recycling powders such as massage powder.

[0022] like Figures 1-4 As shown, in some embodiments, the device includes a dust removal unit, a screw conveyor, and a control unit.

[0023] The dust removal unit is mainly used to separate and capture dust particles from the dust-laden gas, and collect the captured dust into the ash hopper 4 located below the dust removal unit. The dust removal unit includes a dust collector body 3, a filter assembly 10 disposed inside the dust collector body 3, and a pulse jet cleaning unit 1 disposed on the upper part of the dust collector body 3. A dust-laden gas inlet 9 and a clean gas outlet 2 are respectively provided on the side of the dust collector body 3.

[0024] The dust collector body 3 is fixedly installed on the upper part of the equipment frame. The ash hopper 4 adopts a conical structure that is wider at the top and narrower at the bottom. The upper end is welded and fixed to the bottom of the dust collector body 3, and the lower end is sealed and connected to the feed inlet of the screw conveyor unit 6, forming a closed ash collection channel.

[0025] The control unit adopts a PLC integrated control module, which is connected to the dust removal unit and the screw conveyor unit 6 through electrical signal lines.

[0026] The screw conveyor unit 6 is connected to the bottom outlet of the ash hopper 4 via the support frame 13, and the two are connected to each other to convey the dust in the ash hopper 4 to the outside.

[0027] Specifically, the spiral conveying unit 6 includes a drive motor 7, a housing, a spiral shaft 12 disposed within the housing, and spiral blades 11. The radial gap between the outer edge of the spiral blades 11 and the inner wall of the housing is 0.10 mm to 0.30 mm. Within this gap range, the spiral blades 11 can rotate freely without friction against the inner wall of the housing. Simultaneously, the powder forms a shear film layer at the gap, filling the radial gap between the blades and the housing, thus providing auxiliary sealing and effectively preventing moisture penetration. The drive motor 7 is connected to one end of the spiral shaft 12 via a coupling, and the other end of the spiral shaft 12 is connected to an end cover 16. The drive motor 7 drives the spiral shaft 12 and spiral blades 11 to rotate synchronously.

[0028] The specific workflow is as follows: Dust-laden gas enters the dust collector body 3 through the dust-laden gas inlet 9. Under the combined action of airflow diffusion and gravity settling, larger dust particles fall directly into the lower ash hopper 4, while fine dust particles are intercepted on the surface of the filter assembly 10 with the airflow. The filter assembly 10 is a polytetrafluoroethylene (PTFE) membrane filter cartridge, with a polyester non-woven fabric substrate and a PTFE microporous membrane on the surface. The membrane pore size is 0.5μm to 2μm. This membrane structure prevents dust particles from embedding inside the filter material fibers, forming only a loose powder cake layer on the membrane surface. During dust removal, the powder cake is easily peeled off as a whole. The pulse jet cleaning unit 1 includes an air tank, a pulse valve, and a jet pipe. Compressed air is released instantaneously through the pulse valve and high-pressure airflow is injected into the filter cartridge through the nozzle on the jet pipe, causing the filter cartridge to expand instantaneously and vibrate. The surface powder cake layer falls off and into the ash hopper 4.

[0029] The detached powder cake layer quickly slides down to the bottom of the ash hopper 4 under the action of gravity. After being guided by the ash hopper 4, the dust slides evenly into the feed port of the screw conveyor unit 6 along the conical inner wall. The screw shaft 12 rotates at a constant speed under the drive of the drive motor 7. The dust is continuously pushed to the material sealing unit 15 at the rear end by the screw blades 11. The powder forms a stable and dense powder column in the material sealing unit 15. The powder itself blocks the flow of air inside and outside by its own accumulation structure, so as to achieve airtight conveying.

[0030] When upstream production equipment such as screening machines or grinding machines stop working, the control unit receives a shutdown command, delays the shutdown of drive motor 7, and completely empties the residual dust in ash hopper 4 to prevent material caking; at the same time, a certain length of powder column is left inside the material sealing unit 15, and the equipment is kept in a sealed and isolated state during shutdown and static periods to prevent the intrusion of external humid air.

[0031] This implementation method eliminates traditional mechanical sealing components, relying on the material's self-compaction to form a sealing barrier. The sealing performance is stable and durable, effectively preventing moisture backflow and preventing the massage powder from absorbing moisture and clumping. At the same time, the upper and lower equipment are linked for control, enabling continuous production and shutdown protection, and improving the recovery rate and quality of the powder.

[0032] Furthermore, the spiral blades 11 are arranged along the axial direction of the spiral shaft 12, and their pitch P gradually decreases along the discharge direction to form a gradient compression section. When the material passes through this gradient compression section, the conveying volume per unit length decreases as the pitch decreases. The material is subjected to gradually increasing extrusion pressure in the axial direction, which increases the bulk density and reduces the porosity, thus achieving pre-compaction of the powder material before entering the material sealing unit 15.

[0033] During operation, the spiral shaft 12 drives the spiral blades 11 to rotate at a constant speed to transport powder. Fine powder particles naturally fill the tiny gaps between the outer edge of the blades and the inner wall of the shell. Under continuous shearing and extrusion, a dense and stable shear powder film layer is formed. This powder film layer can further seal the tiny gaps and form a double sealing protection with the rear material sealing plunger.

[0034] By combining the gradient compression design of the spiral blades 11 with the synergistic effect of the shear powder film layer, it is possible to avoid operational interference and reduce mechanical wear, while also utilizing the inherent properties of the powder to construct an auxiliary sealing structure, reducing the risk of moisture intrusion and improving overall airtightness, thereby ensuring the dryness of the powder during the conveying process.

[0035] It should be noted that a material sealing unit 15 is provided at the discharge end of the screw conveyor unit 6. The material sealing unit 15 is configured to allow the powder material pushed by the screw conveyor unit 6 to accumulate and compact in it, forming a powder plunger sealing barrier that blocks the passage of gas.

[0036] Specifically, the termination position of the spiral blade 11 is located at the inlet end of the material sealing unit 15, so that the part of the spiral shaft 12 inside the material sealing unit 15 is a bare section without spiral blades.

[0037] Under the continuous pushing of the spiral blades 11, the material enters the material sealing unit 15. In the smooth section, it loses the active pushing effect of the spiral surface and can only move forward by the extrusion force of the subsequent material. Under the constraint of the cavity of the material sealing unit 15, the powder is compacted layer by layer to form a dense powder plunger sealing barrier. The particles inside the powder plunger are tightly packed, with fine powder filling the pores between the large particles, forming a highly dense structure. Gas molecules have difficulty penetrating this barrier, thus effectively blocking the diffusion and migration of external humid air into the ash hopper 4 through the unloading channel.

[0038] As a preferred embodiment, the inner diameter of the sealing unit 15 tapers from the inlet end to the outlet end, with a taper ratio of 1:50 to 1:100. As the powder is pushed forward axially, it is subjected to the radial convergence of the inner wall of the tapered cavity, generating a continuously increasing lateral extrusion force. The powder particles are compressed in all directions, further increasing their density.

[0039] In this embodiment, the combination of axial pushing and radial extrusion significantly improves the barrier capability of the powder plunger, effectively resisting negative pressure and external moisture penetration, and enhancing sealing performance.

[0040] Furthermore, a discharge port 14 is provided on the lower side of the outlet end of the material sealing unit 15, which is connected to the external material receiving unit. The discharge port 14 can realize the controlled discharge of powder by pneumatic or gravity. A pressure sensor is set at this location to monitor the pressure change at the front end of the powder plunger in real time. When the pressure value reaches the preset threshold, the discharge mechanism is automatically triggered and the powder column is discharged from the discharge port 14.

[0041] As a preferred embodiment, an anti-bridging unit is provided on the outer side of the ash hopper 4. The anti-bridging unit applies vibration and airflow disturbance to the powder accumulated in the ash hopper 4, effectively destroying the static friction and arching effect between powder particles, so that the powder continues to loosen and maintain good flowability, thereby avoiding material feeding interruption caused by material bridging.

[0042] Specifically, the anti-bridging unit includes an anti-bridging actuator 5 and an anti-bridging controller 8. During operation, the anti-bridging actuator 5 is intermittently started and stopped at a preset frequency by the anti-bridging controller 8 to disrupt the arch structure of the powder. The anti-bridging actuator 5 includes a vibrator and a micro-orifice airflow injector, which are alternately arranged along the circumference of the ash hopper 4. The vibrator is a high-frequency micro-pneumatic vibration structure, and the micro-orifice airflow injector is connected to a low-pressure clean air source, with its nozzle facing the powder layer on the inner wall of the ash hopper 4, resulting in a gentle airflow without dust generation.

[0043] The working process of the anti-bridging unit: A material level detection sensor is installed inside the ash hopper 4 to monitor the material falling status in real time. When the sensor detects that the powder flow rate is lower than the threshold or that there is a tendency to stagnate, the anti-bridging controller 8 immediately starts the vibrator and the micro-pore air jet to work together. The vibrator generates high-frequency micro-vibration to loosen the agglomerated powder, and the micro-pore air jet releases low-pressure airflow to penetrate into the powder gaps, destroying the powder agglomeration and adhesion. The mechanical disturbance combined with the airflow fluidization has a dual effect to break down stubborn bridging and agglomerated materials in all directions.

[0044] It should be noted that the control unit is also connected in communication with the anti-bridging unit and is configured to: when bridging of powder is detected in the ash hopper 4, control the anti-bridging actuator 5 to start intermittent operation to destroy the powder arch structure.

[0045] The specific workflow for this application is as follows: Step 1: Dust Collection Dust-laden gas enters the dust collector body 3 through the dust-laden gas inlet 9. Under the combined action of airflow diffusion and gravity settling, larger dust particles fall directly into the lower dust hopper 4. Fine dust rises with the airflow and reaches the surface of the filter element 10. The filter element 10 is a polytetrafluoroethylene membrane filter cartridge. Dust particles are intercepted on the outer surface of the filter cartridge, and clean gas passes through the filter cartridge and is discharged through the clean gas outlet 2.

[0046] Step 2: Ash Hopper Aggregation As the dust removal process continues, a powder cake layer gradually forms on the surface of the filter element 10. When the pressure difference between the inside and outside of the filter cartridge reaches a preset value, the pulse jet unit 1 is activated, and compressed air is released instantaneously through the pulse valve. High-pressure airflow is then injected into the filter cartridge through the jet pipe, causing the filter cartridge to expand instantaneously and vibrate. The powder cake layer on the surface peels off and falls into the ash hopper 4. Under the action of gravity, the powder slides smoothly down the wall and collects at the bottom outlet of the ash hopper 4.

[0047] Step 3: Screw Conveying and Pre-compaction The powder material collected at the bottom of the ash hopper 4 enters the screw conveyor unit 6. The drive motor 7 drives the screw shaft 12 to rotate through the reducer, and the screw blades 11 push the powder material axially in the discharge direction. When the material passes through the gradient compression section, as the pitch P of the screw blades 11 gradually decreases along the discharge direction, the conveying volume per unit length decreases, and the material is subjected to gradually increasing axial compressive force, resulting in increased bulk density and decreased porosity, thus completing pre-compaction.

[0048] Step 4: Formation of a powder plunger within the material sealing unit The pre-compacted powder material is continuously pushed into the sealing unit 15. Since the termination position of the spiral blades 11 is located before the inlet end of the sealing unit 15, the portion of the spiral shaft 12 within the sealing unit 15 is a smooth section without spiral blades. After entering the sealing unit 15, the material loses the active pushing effect of the spiral surface and can only move forward by the extrusion thrust of subsequently entering materials. Under the constraint of the cavity of the sealing unit 15, the powder is compacted layer by layer, forming a dense powder plunger sealing barrier.

[0049] Step 5: Sealed Discharge and Collection Under normal operating conditions, the powder plunger in the material sealing unit 15 is dynamically updated in a first-in, first-out (FIFO) manner: the spiral blades 11 continuously push new material into the rear end of the material sealing unit 15, pushing the entire plunger forward, and the material at the front end is pushed out of the material sealing unit 15 and falls into the receiving box through the discharge port 14. Because the material sealing unit 15 always maintains a dense plunger of constant length, it continuously provides a sealing barrier during discharge, ensuring that outside air does not enter the ash hopper 4 through the discharge channel.

[0050] Step Six: Anti-bridging measures (optional trigger) When the powder material in hopper 4 forms a bridging arch structure due to internal friction and adhesion, the level sensor detects an abnormal signal, and the control unit immediately triggers the anti-bridging program: First, the vibrator in the anti-bridging actuator 5 is controlled to intermittently strike the outer wall of hopper 4 at a preset frequency, loosening the powder around the arch structure; then, after a delay following the start of the striking, the microporous air jet injector is activated, and low-pressure compressed air is evenly infiltrated into the powder through the microporous plate, destroying the residual supporting force of the arch foot from the bottom of the arch structure. The synergistic effect of vibration and airflow causes the powder arch structure to completely collapse, and the material resumes gravity flow.

[0051] Step 7: Shutdown and Material Seal Maintenance When the control unit receives a shutdown signal from the upstream production equipment, it executes the following material seal maintenance procedure: The fan of the dust removal unit is delayed and stopped for 3 to 5 minutes. During this period, although no new dust enters at the dust-laden gas inlet 9, the fan continues to run to keep the airflow in the system flowing, and continues to transport the residual dust suspended in the pipes and box to the surface of the filter component 10 for capture. The pulse jet unit 1 is controlled to increase the jet pressure from the normal operating pressure to 0.6MPa to 0.7MPa, and each filter cartridge is continuously jetted 3 to 5 times. The time interval between two adjacent jets is shortened to 50% of the normal operating interval, so that the residual powder cake on the surface of the filter cartridge is completely peeled off. After the blower stops, the screw conveyor unit 6 continues to run for 2 to 5 minutes to discharge all the remaining material collected in the ash hopper 4, leaving the ash hopper 4 empty. The discharged material enters the receiving box through the material sealing unit 15 and the discharge port 14. At the same time, when the screw conveyor unit 6 stops, the material sealing unit 15 retains an intact powder plunger to maintain the seal.

[0052] After the above procedures, the device enters standby mode: the filter cartridge surface is dry and clean to prevent residual powder cake from absorbing moisture and caking and clogging the filter holes; there is no accumulated material in the ash hopper 4 to prevent the powder from absorbing moisture and clumping after a long period of static storage; the material sealing unit 15 retains an intact powder plunger to continuously isolate the outside humid air from entering the dust collector.

[0053] Step 8: Forced evacuation during long-term shutdown When the control unit determines that the downtime of the upstream production equipment exceeds a preset threshold (e.g., planned downtime exceeding 4 hours), it executes a long-term shutdown forced evacuation procedure: The screw conveyor unit 6 continues to run until the level sensor in the ash hopper 4 displays an empty signal, then continues running for an additional time to completely evacuate the powder plungers in the material sealing unit 15. This evacuated material is discharged into a sealed transfer container for separate storage; its reuse is only determined after quality verification. Upon the next startup, the screw conveyor unit 6 starts under no-load conditions. Once the material refills the material sealing unit 15 and establishes a new powder plunger sealing barrier, the unit resumes normal operation.

[0054] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0055] The embodiments have been described above, and such description is not restrictive. The figures shown are only one embodiment, and the actual structure is not limited to this. In short, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the inventive spirit, such design should fall within the scope of protection.

Claims

1. A device for recycling powders such as massage powder, characterized in that, include: The dust removal unit includes a dust collector body (3) and a filter assembly (10) disposed in the dust collector body (3). The lower part of the dust collector body (3) is provided with a dust hopper (4). The filter assembly (10) is used to separate and capture dust particles from the dust-laden gas and collect the captured dust in the dust hopper (4). The screw conveyor unit (6) includes an inlet end and an outlet end. The inlet end is connected to the bottom outlet of the ash hopper (4). The outlet end of the screw conveyor unit (6) is connected to a material sealing unit (15). The material sealing unit (15) is configured to allow the powder material pushed by the screw conveyor unit (6) to accumulate and compact therein, forming a powder plunger sealing barrier that blocks the passage of gas. The control unit is communicatively connected to the dust removal unit and the screw conveyor unit (6), respectively. The control unit is configured to: respond to the shutdown signal of the upstream production equipment, control the screw conveyor unit (6) to continue running for a preset time after the dust removal unit stops, so as to discharge the remaining material in the ash hopper (4) and keep the intact powder plunger in the material sealing unit (15) to maintain the seal.

2. The device for recovering powders such as massage powder according to claim 1, characterized in that, The spiral conveying unit (6) includes a housing, a spiral shaft (12) disposed within the housing, and spiral blades (11). The radial gap between the outer edge of the spiral blades (11) and the inner wall of the housing is 0.10 mm to 0.30 mm, so as to allow the powder to form a shear powder film layer for auxiliary sealing at the gap.

3. The device for recovering powders such as massage powder according to claim 2, characterized in that, The pitch P of the spiral blade (11) gradually decreases along the discharge direction to pre-compact the powder material before it enters the material sealing unit (15).

4. The device for recovering powders such as massage powder according to claim 2, characterized in that, The spiral blade (11) is arranged along the axial direction of the spiral shaft (12), and the termination position of the spiral blade (11) is located before the inlet end of the material sealing unit (15), so that the spiral shaft (12) part in the material sealing unit (15) is a bare rod section without spiral blades.

5. The device for recovering powders such as massage powder according to claim 2, characterized in that, The inner diameter of the material sealing unit (15) tapers from the inlet end to the outlet end to apply a gradually increasing radial extrusion force to the powder material as it is pushed axially.

6. The device for recovering powders such as massage powder according to claim 1, characterized in that, The dust removal unit also includes a pulse jet cleaning unit (1) disposed on the upper part of the dust collector body (3), and the filter assembly (10) is a polytetrafluoroethylene membrane filter cartridge; The dust collector body (3) is provided with a dust-laden gas inlet (9) and a clean gas outlet (2) on its side.

7. The device for recovering powders such as massage powder according to claim 1, characterized in that, The outer side of the ash hopper (4) is provided with an anti-bridging unit, which includes an anti-bridging actuator (5) and an anti-bridging controller (8). The anti-bridging actuator (5) is started and stopped intermittently at a preset frequency by the anti-bridging controller (8). The control unit is also communicatively connected to the anti-bridging unit and is configured to: when bridging of powder is detected in the ash hopper (4), control the anti-bridging actuator (5) to start intermittent operation to destroy the powder arch structure.

8. The device for recovering powders such as massage powder according to claim 1, characterized in that, The anti-bridging actuator (5) includes a vibrator and a micro-hole air jet injector, which are arranged alternately along the circumference of the ash hopper (4).

9. The device for recovering powders such as massage powder according to claim 5, characterized in that, It also includes a discharge port (14), which is located below the outlet end of the material sealing unit (15) and is connected to an external receiving box.

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