Powder remover and powder removal method

Abstract

The present invention discloses a powder remover and a powder removal method, and relates to the technical field of powder removers for plastic particles, wherein the powder remover comprises an external air supply channel, a particle conveying channel and a powder removal channel, wherein the powder removal channel is vertically arranged, the lower end of the powder removal channel is closed, and the upper end has an air outlet; the particle conveying channel and the external air supply channel are both spirally wound in the same direction on the outside of the powder removal channel, each circle of the particle conveying channel is connected to the powder removal channel through a plurality of first ventilation channels, and each circle of the external air supply channel is connected to the corresponding circle of the particle conveying channel through a plurality of second ventilation channels; the upper end of the particle conveying channel has a feed port, and the lower end has a discharge port, the lower end of the external air supply channel has an air inlet, and the upper end is closed. The powder removal rate of the powder remover is 95-99%, and the powder removal rate is high.

Description

Technical Field

[0001] The invention belongs to the technical field of powder removers for plastic particles, and in particular relates to a powder remover. Background Art

[0002] Plastic particles refer to granular plastics, including general-purpose plastics (such as polypropylene, polyethylene, polyvinyl chloride, etc.), engineering plastics (such as nylon, polytetrafluoroethylene, polycarbonate silicone, etc.) and special plastics (such as thermosetting plastics, functional polymer plastics, etc.). The production process of plastic particles generally requires granulation, screening, pneumatic conveying, blending, storage, packaging and other processes, and finally forms granular plastic products. In the above production process, fine powder, wire drawing and fragments and other dusts will be generated. Wire drawing and fragments can be effectively removed by the upstream elutriation system, while fine powder will be mixed in the plastic particles or electrostatically adsorbed on the surface of plastic particles, thereby reducing the quality and grade of plastic particle products, and at the same time will cause dust explosion safety hazards in packaging, warehousing, transportation and downstream user production. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a powder remover and a powder removal method, which can effectively remove dust from plastic particles, improve the product quality and grade of plastic particles, and eliminate the safety hazard of dust explosion.

[0004] The technical solution of the present invention is:

[0005] In one aspect, the present invention provides a deduster, the deduster comprising an external air supply channel, a particle conveying channel and a deduster channel, wherein:

[0006] The powder removal channel is vertically arranged, the lower end of the powder removal channel is closed, and the upper end has an air outlet;

[0007] The particle conveying channel and the external air supply channel are both spirally wound in the same direction on the outside of the powder removal channel, each circle of the particle conveying channel is connected to the powder removal channel through a plurality of first ventilation channels, and each circle of the external air supply channel is connected to the corresponding circle of the particle conveying channel through a plurality of second ventilation channels;

[0008] The particle conveying channel has a feed port at its upper end and a discharge port at its lower end. The external air supply channel has an air inlet at its lower end and is closed at its upper end.

[0009] Furthermore, the cross-sectional dimensions of the first ventilation channel and the second ventilation channel are smaller than the maximum dimension of the particles transported by the particle transport channel.

[0010] Furthermore, the distance between the center line of each circle of the external air supply channel and the powder removal channel is greater than the distance between the center line of the particle conveying channel of the corresponding circle and the powder removal channel.

[0011] Furthermore, the centerline height of each circle of the external air supply channel is lower than the centerline height of the particle transport channel of the corresponding circle.

[0012] Furthermore, the angle between each circle of the particle conveying channel and the center line of the powder removal channel is 15-45°.

[0013] Furthermore, the angle between the center line of each circle of the particle conveying channel and the powder removal channel is 30-40°

[0014] Furthermore, the powder remover also includes an internal air supply channel, which is spirally wound around the outside of the powder removal channel in the same direction as the particle transport channel, and each circle of the internal air supply channel is arranged between the corresponding circle of the particle transport channel and the powder removal channel, and each circle of the internal air supply channel is connected with the powder removal channel, and each circle of the internal air supply channel is connected with the corresponding circle of the particle transport channel through the first ventilation channel, and the upper and lower ends of the internal air supply channel are both closed.

[0015] In another aspect, the present invention provides a powder removal method, which uses the above-mentioned powder removal device to remove powder, and the method comprises:

[0016] Add plastic particles to the feed port of the particle conveying channel, and simultaneously supply air to the air inlet of the external air supply channel;

[0017] The air in the external air supply channel enters the particle conveying channel through the second ventilation channel, and reacts with the particles in the particle ventilation channel to carry away the dust;

[0018] The air containing the dust enters the powder removal passage through the first ventilation passage and is discharged from the air outlet of the powder removal passage.

[0019] Furthermore, the maximum size of the plastic particles is less than 15 mm, and the particle size of the dust is ≤ 500 μm.

[0020] Furthermore, the unit cross-sectional flux of the plastic particles is less than 500 t / h, and the unit cross-sectional flux of the external air supply channel is less than or equal to 200,000 Nm 3 / h, the air supply pressure of the external air supply channel is ≤60KPa.

[0021] The beneficial effects of the present invention include at least:

[0022] The powder remover provided by the present invention comprises an external air supply channel, a particle conveying channel and a powder removal channel. Plastic particles enter through the feed port at the upper end of the particle conveying channel. Under the action of gravity, the plastic particles move from the upper end to the lower end along the spirally wound particle conveying channel. At the same time, air is supplied into the air inlet at the lower end of the external air supply channel, and the wind moves from the lower end to the upper end along the external air supply channel. Since each circle of the external air supply channel and the corresponding circle of the particle conveying channel are connected through a plurality of second ventilation channels, the air in the external air supply channel will move toward the particle conveying channel along the second ventilation channel under the action of pressure, and the moving air and the particle conveying channel will be The moving air has speed and the mass of the dust is small. The moving air can overcome the mass of the dust and the adhesion between the dust and the plastic particles. The dust will move with the moving air, and each circle of particle conveying channel is connected with the powder removal channel through multiple first ventilation channels. Therefore, the air mixed with dust will move along the first ventilation channels to the powder removal channel, and the lower end of the powder removal channel is closed. The air mixed with dust can only rush out from the air outlet at the upper end of the powder removal channel. Since the air runs from bottom to top and the particles run from top to bottom, the effective area is large and the dust removal effect is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the three-dimensional structure of a powder remover of this embodiment;

[0024] Figure 2 for Figure 1 Schematic diagram of the local structure;

[0025] Figure 3 for Figure 1 Schematic diagram of the structure of the particle transport channel;

[0026] Figure 4 for Figure 1 Cross-sectional view through the center axis of the powder removal channel.

[0027] Description of reference numerals:

[0028] 1-powder removal channel, 101-air outlet;

[0029] 2-Internal air supply channel;

[0030] 3-particle transport channel, 301-feeding port, 302-discharging port, 303-first ventilation surface, 304-second ventilation surface;

[0031] 4-external air supply channel, 401-air inlet;

[0032] 5- first ventilation channel;

[0033] 6- Second air supply channel. DETAILED DESCRIPTION

[0034] In order to enable technicians in the technical field to which the present application belongs to understand the present application more clearly, the technical solution of the present application is described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0035] Figure 1 is a schematic diagram of the three-dimensional structure of a deduster in this embodiment, Figure 2 for Figure 1 Schematic diagram of the local structure, Figure 3 for Figure 1 Schematic diagram of the particle transport channel in FIG. Figure 4 for Figure 1 The cross-sectional view of the central axis of the powder removal channel, combined with Figures 1 to 4 The present invention provides a powder remover, which includes an external air supply channel 4, a particle conveying channel 3 and a powder removal channel 1.

[0036] Among them, the powder removal channel 1 is vertically arranged, the lower end of the powder removal channel 1 is closed, and the upper end has an air outlet 101; the particle conveying channel 3 and the external air supply channel 4 are both spirally wound in the same direction on the outside of the powder removal channel 1, each circle of the particle conveying channel 3 is connected with the powder removal channel 1 through a plurality of first ventilation channels 5, and each circle of the external air supply channel 4 is connected with the corresponding circle of the particle conveying channel 3 through a plurality of second ventilation channels 6; the upper end of the particle conveying channel 3 has a feed port 301, and the lower end has a discharge port 302, the lower end of the external air supply channel 4 has an air inlet 401, and the upper end is closed.

[0037] Plastic particles enter through the feed port 301 at the upper end of the particle conveying channel 3. Under the action of gravity and centrifugal force, the plastic particles move from the upper end to the lower end along the outer side of the spirally wound particle conveying channel 3. At the same time, air is supplied into the air inlet 401 at the lower end of the external air supply channel 4. The wind moves from the lower end to the upper end along the external air supply channel 4. Since each circle of the external air supply channel 4 and the corresponding circle of the particle conveying channel 3 are connected through multiple second ventilation channels 6, the air in the external air supply channel 4 will move toward the particle conveying channel 3 along the second ventilation channels 6 under the action of pressure. The moving air meets the particles. Air has speed and the mass of dust is small. The moving air can overcome the mass of dust and the adhesion between dust and plastic particles. The dust will move with the moving air, and each circle of particle conveying channel 3 is connected to the powder removal channel 1 through multiple first ventilation channels 5. Therefore, the air mixed with dust will move along the first ventilation channels 5 to the powder removal channel 1, and the lower end of the powder removal channel 1 is closed. The air mixed with dust can only rush out from the air outlet 101 at the upper end of the powder removal channel 1. Since the air running path is from bottom to top and the particle running path is from top to bottom, the effective area is large and the dust removal effect is good.

[0038] If the lower end of the powder removal channel 1 has an air supply port and the upper end is sealed, the external air supply channel 4 serves as a dust collection channel. Due to the centrifugal effect of the particles in the spiral motion, they will be along the outer side of the particle conveying channel 3, and the dust in the plastic particles can also be removed.

[0039] The particle conveying channel 3 is arranged in a spiral shape, which can increase the residence time of the plastic particles in the particle conveying channel 3, thereby increasing the action time of air and plastic particles, thereby removing dust attached to the plastic particles.

[0040] In practice, the cross section of the particle conveying channel 3 can be rectangular or circular, which is not limited here. The first ventilation channel 5 is recommended to be arranged on the two side surfaces of the particle conveying channel 3 and the powder removal channel 1 that are close to each other. Of course, the second ventilation channel 6 is recommended to be arranged on the two measuring surfaces of the particle conveying channel 3 and the external air supply channel 4 that are close to each other.

[0041] Preferably, in this embodiment, the cross-sectional dimensions of the first ventilation channel 5 and the second ventilation channel 6 are smaller than the maximum dimension of the particles transported by the particle transport channel 3, thereby effectively preventing the plastic particles from entering the powder removal channel 1 and the external air supply channel 4 from the particle transport channel 3.

[0042] Preferably, combined Figure 2 and Figure 4 In the present embodiment, the distance between the center line of each circle of the external air supply channel 4 and the powder removal channel 1 is greater than the distance between the center line of the corresponding circle of the particle conveying channel 3 and the powder removal channel 1. In this way, the inner side of each circle of the external air supply channel 4 can be fitted with the outer side of the corresponding circle of the particle conveying channel 3. In a specific implementation, the part where the inner side of each circle of the external air supply channel 4 is fitted with the outer side of the corresponding circle of the particle conveying channel 3 can share a second ventilation surface 304, and a plurality of second ventilation holes are opened on the second ventilation surface 304 as the second ventilation channel 6. The second ventilation surface 304 can adopt a grille structure or a mesh structure.

[0043] More preferably, in combination Figure 2 as well as Figure 4 In this embodiment, the centerline height of each circle of the external air supply channel 4 is lower than the centerline height of the corresponding circle of the particle conveying channel 3, so that the air can enter the particle conveying channel 3 obliquely upward, the upward air and the downward particles have a larger contact area, and the relative movement of the two is more conducive to separating the dust from the plastic particles.

[0044] Specifically, in this embodiment, the powder removal channel can be cylindrical or rectangular. The specific shape can be flexibly adjusted according to the difficulty of processing and is not limited here.

[0045] Preferably, in this embodiment, the angle between each circle of the particle conveying channel 3 and the center line of the powder removal channel 1 is 15-45°.

[0046] By controlling the angle between the particle conveying channel 3 and the center line of the powder removal channel 1, the residence time of the plastic particles in the particle conveying channel 3 can be controlled, thereby controlling the action time between the air and the plastic particles. If the angle between the particle conveying channel 3 and the center line of the powder removal channel 1 is too large, the plastic particles will run too fast and the dust removal efficiency will be low; if the angle between the particle conveying channel 3 and the center line of the powder removal channel 1 is too small, the plastic particles will run too slowly and the production efficiency will be low. In the present invention, the angle between each circle of the particle conveying channel 3 and the center line of the powder removal channel 1 is preferably 30-40°.

[0047] Furthermore, combined with Figure 2 as well as Figure 4 The deduster may also include an inner air supply channel 2, the inner air supply channel 2 and the particle conveying channel 3 are spirally wound in the same direction on the outside of the deduster channel 1, each circle of the inner air supply channel 2 is arranged between the particle conveying channel and the deduster channel 1 of the corresponding circle, each circle of the inner air supply channel 2 is connected with the deduster channel 1, each circle of the inner air supply channel 2 is connected with the particle conveying channel 3 of the corresponding circle through the first ventilation channel 5, and the upper and lower ends of the inner air supply channel 2 are both closed. The upwardly moving air meets the particles moving downward in the particle conveying channel 3, and the air carries the dust with a smaller mass in the particle conveying channel 3 and enters the inner air supply channel 2 through the first ventilation channel 5. Since the inner air supply channel 2 is connected with the deduster channel 1, the air carrying a large amount of dust enters the deduster channel 1 under the action of pressure, mixes and rises, and escapes from the air outlet 101 at the upper end of the deduster channel 1.

[0048] In actual operation, the inner side of each circle of particle conveying channel 3 can be arranged in close contact with the outer side of the inner air supply channel 2 of the corresponding circle, and the part where the particle conveying channel 3 and the inner air supply channel 2 are arranged in close contact can share a first ventilation surface 303, and a plurality of first ventilation holes are provided on the first ventilation surface 303 as the first ventilation channel; the inner side of the inner air supply channel 2 can be completely connected with the powder removal channel 1. The first ventilation surface 303 can adopt a grid structure or a mesh structure.

[0049] During specific operation, three air inlets 401 of the external air supply channel 4 may be provided. The three air inlets 401 are provided at the lower side of a circle at the lower end of the external air supply channel 4 , and the three air inlets 401 are distributed by one air supply duct.

[0050] On the other hand, an embodiment of the present invention further provides a powder removal method, which uses the above-mentioned powder removal device to remove powder, and the method comprises:

[0051] S1, adding plastic particles into the feed port of the particle conveying channel, and simultaneously supplying air to the air inlet of the external air supply channel;

[0052] Furthermore, the maximum size of the plastic particles is less than 15 mm.

[0053] In the art, plastic particles may be spherical or cylindrical, and the maximum size of the plastic particles is generally less than 15 mm. Of course, plastic particles of other sizes are also applicable to the present invention.

[0054] Furthermore, the unit cross-sectional flux of the plastic particles is less than 500 t / h, and the unit cross-sectional flux of the external air supply channel is less than or equal to 200,000 Nm 3 / h, the air supply pressure of the external air supply channel is ≤60KPa.

[0055] The above-mentioned unit cross-sections all refer to 1 square meter.

[0056] The flow rate of the plastic particles and the air flow rate of the external air supply channel have the above matching relationship, and the air flow rate of the external air supply channel and the solid-gas ratio of the plastic particles are 0.817-2.735. The solid-gas ratio here refers to the ratio of the mass flow rate of the plastic particles to the mass flow rate of the conveying gas.

[0057] If the flow rate of plastic particles is too large, the dust removal rate will be low. If the flow rate of plastic particles is too small, the production efficiency will be low. If the air flow rate of the external air supply channel is too large, the dust removal rate will not be significantly improved. If the air flow rate of the external air supply channel is too small, the dust removal efficiency will be low.

[0058] S2, the air in the external air supply channel enters the particle conveying channel through the second ventilation channel, and reacts with the particles in the particle ventilation channel to take away the dust;

[0059] Furthermore, the particle size of the dust is ≤500 μm.

[0060] S3, the air containing the dust enters the powder removal channel through the first ventilation channel and is discharged from the air outlet of the powder removal channel.

[0061] The powder removal method provided by the present invention will be further described below in conjunction with specific embodiments.

[0062] Example 1

[0063] The above-mentioned powder remover is used for powder removal, and the process control of powder removal is as follows:

[0064] The maximum size of plastic particles is 3.5mm-4.5mm, and the density is 1100Kg / m 3 The unit cross-sectional flux of plastic particles is 480t / h, and the unit cross-sectional flux of the external air supply channel is 180000Nm 3 / h, the air supply pressure is 40.8KPa.

[0065] Example 2

[0066] The above-mentioned powder remover is used for powder removal, and the process control of powder removal is as follows:

[0067] The maximum size of plastic particles is 5mm-6mm and the density is 983Kg / m 3 The unit cross-sectional flux of plastic particles is 200t / h, and the unit cross-sectional flux of the external air supply channel is 110000Nm 3 / h, the air supply pressure is 41.6KPa.

[0068] Example 3

[0069] The above-mentioned powder remover is used for powder removal, and the process control of powder removal is as follows:

[0070] The maximum size of plastic particles is 13mm-15mm, and the density is 915Kg / m 3 The unit cross-sectional flux of plastic particles is 200t / h, and the unit cross-sectional flux of the external air supply channel is 980000Nm 3 / h, the air supply pressure is 47.7KPa. .

[0071] Using the powder removal methods provided in Examples 1 to 3, the dust contents of the plastic particles were 3000ppm, 2000ppm and 1000ppm, respectively, before powder removal, and were 142ppm, 34ppm and 28ppm, respectively, after powder removal, and the powder removal rates were 95.2%, 98.3% and 97.2%, respectively.

[0072] The present invention adopts a spatial spiral structure with a gradually changing base circle and lead. Plastic particles move in the particle conveying channel of the spatial spiral by gravity flow. The width and angle of the particle conveying channel are designed so that the plastic particles have enough residence time in the particle conveying channel and form a suitable material layer thickness. Powder removal air is introduced into the lower end of the spirally arranged external air supply channel. By setting the distribution of the powder removal air and adjusting the flow rate and pressure of the powder removal air, the powder removal air causes the plastic particles to form a fluidized state in the particle conveying channel, so that the dust is separated and taken away by the powder removal air, and is discharged into the internal air supply channel through the first ventilation channel on the inner wall of the particle conveying channel, and finally converges into the powder removal channel and is discharged. The powder removal device provided by the present invention is used to remove dust from plastic particles, and the powder removal rate can reach 95%-99%, which is a high powder removal rate.

[0073] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0074] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A powder remover, characterized in that: The deduster includes an external air supply channel, a particle conveying channel and a deduster channel, wherein: The powder removal channel is vertically arranged, the lower end of the powder removal channel is closed, and the upper end has an air outlet; The particle conveying channel and the external air supply channel are both spirally wound in the same direction on the outside of the powder removal channel, the distance between the center line of each circle of the external air supply channel and the powder removal channel is greater than the distance between the center line of the corresponding circle of the particle conveying channel and the powder removal channel, the center line height of each circle of the external air supply channel is lower than the center line height of the corresponding circle of the particle conveying channel, each circle of the particle conveying channel is connected to the powder removal channel through a plurality of first ventilation channels, so that the air mixed with dust moves along the first ventilation channel to the powder removal channel, and each circle of the external air supply channel is connected to the corresponding circle of the particle conveying channel through a plurality of second ventilation channels; The particle conveying channel has a feed port at its upper end and a discharge port at its lower end. The external air supply channel has an air inlet at its lower end and is closed at its upper end.

2. A powder remover according to claim 1, characterized in that: The cross-sectional dimensions of the first ventilation channel and the second ventilation channel are smaller than the maximum dimension of the particles transported by the particle transport channel.

3. A powder remover according to claim 1, characterized in that: The angle between the center line of each circle of the particle conveying channel and the powder removal channel is 15-45°.

4. A powder remover according to claim 3, characterized in that: The angle between the center line of each circle of the particle conveying channel and the powder removal channel is 30-40°.

5. A powder remover according to any one of claims 1 to 4, characterized in that: The powder remover also includes an internal air supply channel, which is spirally wound around the outside of the powder removal channel in the same direction as the particle conveying channel, and each circle of the internal air supply channel is arranged between the corresponding circle of the particle conveying channel and the powder removal channel, and each circle of the internal air supply channel is connected with the powder removal channel, and each circle of the internal air supply channel is connected with the corresponding circle of the particle conveying channel through the first ventilation channel, and the upper and lower ends of the internal air supply channel are both closed.

6. A powder removal method, characterized in that: A powder removal device according to any one of claims 1 to 5 is used to remove powder, the method comprising: Add plastic particles to the feed port of the particle conveying channel, and simultaneously supply air to the air inlet of the external air supply channel; The air in the external air supply channel enters the particle conveying channel through the second ventilation channel, and reacts with the particles in the particle conveying channel to carry away the dust; The air containing the dust enters the powder removal passage through the first ventilation passage and is discharged from the air outlet of the powder removal passage.

7. A powder removal method according to claim 6, characterized in that: The maximum size of the plastic particles is less than 15 mm, and the particle size of the dust is less than or equal to 500 μm.

8. A powder removal method according to claim 6, characterized in that: The flux per unit cross section of the plastic particles is less than 500 t / h, and the flux per unit cross section of the external air supply channel is less than or equal to 200,000 Nm 3 / h, the air supply pressure of the external air supply channel is ≤60KPa.

Images