JP2018058001A - Powder dispersion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder dispersion device capable of properly achieving aerosolization with high dispersion by improving the flowability of powders.SOLUTION: In a powder dispersion device which comprises a powder feeder 1 and a powder disperser 2 dispersing powders and where the powders are fallen from the powder feeder 1 into the dispersion cylinder 5 of the powder disperser 2 via a powder supply pipe 4 and discharged from an aerosol discharge pipe 7 as a swirl vortex flow by the blade 12 of an impeller 6 on the bottom 13 of the dispersion cylinder 5,: the dispersion cylinder 5 corresponding to the lower edge corresponding part of the impeller 6 and the bottom 13 are curved; the shape of the dispersion cylinder upper than the upper edge corresponding part of the impeller 6 is reverse conical or reverse circular cross sectional; the lower shape of the cross section of the blade 12 of the impeller 6 is triangular; and a space between the lower edge of the blade 12 of the impeller 6 and the curved bottom 13 can be approximately 5-20 mm.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a powder dispersion apparatus for discharging powder together with air as dust of particles in which powder is completely dispersed, and more particularly to a structurally improved structure of a powder aerosol generator.

  Recent powder dispersers use a specially structured impeller that rotates at high speed with a motor. First, a small amount of powder is supplied to the disperser with a microfeeder with high accuracy without pulsation, and then In a powder disperser, the powder was dispersed into a dust flow by an impeller rotated at high speed by a motor, aerosolized in the air, and discharged from a discharge port. In this case, the dispersion cylinder of the powder disperser was a floor surface with a cylindrical side surface and a flat bottom surface, and the impeller was installed on a flat surface (see Patent Document 1).

  As shown in FIG. 1, the outline of the basic configuration of the powder dispersion apparatus is composed of a powder supply machine 1 and a rotary blade type dispersion machine 2. The powder supply machine 1 can supply a small quantity to a large quantity. Various powder feeders are commercially available, and the powder 3 used in the powder aerosol generator and the powder feeder 1 corresponding to the amount of aerosol supplied can be freely selected and adopted.

  As shown in FIG. 1, the basic configuration of the rotary vane type disperser includes a powder supply pipe 4, a dispersion cylinder 5, an impeller 6, and an aerosol discharge pipe 7. Separately, the powder 3 discharged from the installed powder supply machine 1 falls into the dispersion cylinder 5 via the powder supply pipe 4. It collides with the impeller 6 that rotates at high speed by a power mechanism composed of the motor 9, the pulley 10, and the belt 11, and generates a shearing effect on the agglomerated particles in the powder. Further, a shearing effect is also generated in the agglomerated powder flowing in a narrow space between the tip of the impeller 6 composed of about 4 to 6 blades 12 fixed to the pulley shaft 15 and the inner wall of the dispersion cylinder 5. The gas flow generated by the impeller 6 rotating at high speed and the powder 3 are mixed to form a powder aerosol 8 and discharged from the aerosol discharge pipe 7. The impeller 6 is composed of 4 to 6 blades 12. The rotational speed of the impeller 6 has a structure that fluctuates by about 20,000 rpm to 5,000 rpm, and the amount of air flowing into the dispersion cylinder 5 along with the powder 3 from the powder supply pipe 4 is the rotational speed. Related to. Further, a bypass suction port 18 is further provided in the part of the powder supply pipe 4 to increase the amount of air flowing in, or the amount of air flowing in can be reduced by restricting the powder supply pipe 4 and the bypass suction port 18. can do. As a result, it is possible to arbitrarily adjust the air concentration.

  In the conventional powder dispersing apparatus, one of the countermeasures is to increase the processing speed of the powder 3 or to increase the rotation speed of the impeller 6 in order to improve the dispersion effect of the agglomerated powder. For this purpose, the dispersion cylinder 5 and the bottom 13 are orthogonal to each other, and there is a structural problem that significantly impedes the flow of powder. Further, the upper part 14 of the dispersion cylinder 5 is also orthogonal and needs to be improved.

FIG. 2 shows a basic configuration of a rotary blade disperser widely used as a prior art. This structure has a circular inlet (powder supply pipe 4) and outlet (aerosol discharge pipe 7), and a constant area. However, it may be rectangular, and the dispersion cylinder 5 is orthogonal to the bottom 13 and the top 14. This is a structure based on the design of a powder dispersion apparatus in which the supply amount (processing amount) of the powder 3 is 100 kg / h and 20 m ³ / min.

Japanese Patent No. 5768946 Registered Utility Model No. 3073685

  An object of the present invention is to provide a powder dispersion apparatus that can improve the fluidity of a powder, achieve a good yield, and can produce an appropriate powder aerosol with high dispersibility.

  A further object of the present invention is to increase the dispersion force and aerosolization by structural improvement of the bottom 13 and top 14 of the dispersion cylinder in the powder dispersion apparatus.

  The problem is that, in the powder dispersion apparatus according to claim 1, the dispersion cylinder 5 and the bottom 13 corresponding to the lower end equivalent portion of the impeller 6 are formed in a curved shape, thereby improving the fluidity of the powder and improving the dispersion force. . Similarly, the configuration according to claim 2, that is, the upper end of the dispersion cylinder having an inverted conical shape or an inverted circular cross-sectional shape is also achieved to improve the fluidity of the powder and improve the dispersion force. .

  Furthermore, the problem is that the cross-sectional shape of the blade 12 of the impeller 6 in the powder dispersing apparatus according to claim 3 can be made triangular, and the stirring effect of the blade 12 can be enhanced, and the dispersion force of the powder can be improved. Increase the fluidity of the powder.

  Further, the clearance between the lower part of the blade of the impeller 6 and the curved bottom part 13 in the powder dispersing apparatus according to claim 4 is set to 5 to 20 mm, thereby improving the Taylor-Gertler vortex effect.

  Furthermore, by providing an appropriate protrusion on the inverted conical shape portion or the inverted circular cross-sectional shape portion of the dispersion cylinder in the powder dispersion apparatus according to claim 5, the turbulence of the mixed flow of gas and powder is generated, The dispersion effect and the adhesion preventing effect on the dispersion cylinder can be enhanced.

  According to the powder dispersing apparatus of the present invention, the powder can be made aerosol by improving the fluidity of the powder and efficiently improving the dispersion of the powder.

  According to the powder dispersion apparatus of the present invention, an appropriate gap is provided between the blade and the dispersion cylinder to improve the Taylor-Gertler vortex effect.

  According to the present invention, the effect of dispersing the powder and the effect of preventing adhesion to the dispersion cylinder can be enhanced by the protrusions suitable for the dispersion cylinder.

  According to this invention, even if the rotation speed of the impeller 6 is the same, the processing amount of the powder 3 can be increased, or the effect of dispersing the aggregated powder can be improved.

(A) is a schematic diagram of a basic configuration of a conventional powder dispersion apparatus, and (b) is an AA cross-sectional view of the basic configuration of the conventional powder dispersion apparatus. (A) is a basic configuration of a prior art rotor blade type disperser, and (b) is a BB cross-sectional view of the prior art rotor blade type disperser. (A) is the basic configuration of the rotor blade type disperser of the present invention, (b) is a DD sectional view of the rotor blade type disperser of the present invention, and (c) is the rotor blade type disperser of the present invention. EE sectional drawing is shown, respectively. (A) is an embodiment of the improved rotor blade of the rotor blade type disperser of the present invention, (b) is a cross-sectional view of the rotor blade disperser of the present invention embodiment of the improved rotor blade FF cross section, (C) shows GG sectional drawing of the one aspect | mode of the improved rotary blade of the rotary blade type | mold disperser of this invention, respectively. (A) is another embodiment of the improved rotor blade of the rotor blade disperser of the present invention, and (b) is an HH cross-sectional view of another embodiment of the improved rotor blade of the rotor blade disperser of the present invention. (C) is a JJ cross-sectional view of another embodiment of the improved rotor blade of the rotor blade type disperser of the present invention. Another aspect of the dispersion cylinder of the rotary blade type disperser of the present invention is shown. (A) is a further embodiment in which the dispersion cylinder of the rotor blade type disperser of the present invention is provided with a protrusion, and (b) is a dispersion in still another embodiment in which the dispersion cylinder of the rotor blade type disperser of the present invention is provided with a protrusion. The projection side surface of the cylinder 5 is shown by (c), which is a sectional view taken along the line K-K of still another embodiment in which the dispersion cylinder of the rotary blade disperser of the present invention is provided with protrusions.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 3 shows the basic configuration of the rotary vane type disperser of the present invention, in which the dispersion cylinder 5 and the bottom 13 are not orthogonal to each other, only the impeller 6 part is a cylinder, and the bottom 13 forms a curved shape. The structure is such that a Taylor-Gertler vortex is generated in the mixed flow of the powder 3 and gas after the impeller 6 flows, and a strong dispersion effect is expected in this portion. In this design, the curved shape of the bottom 13 is an elliptical cross section. Moreover, only a hemispherical cross section or an orthogonal part can be made into a circular cross section. This selection is performed in consideration of the properties of the powder 3, selection of air and other gases, or environmental conditions such as temperature and pressure.

  The impeller 6 is composed of several rectangular blades 12 as shown in the DD cross-sectional view of FIG. Moreover, the shape of the dispersion | distribution cylinder 5 above the upper end part equivalent of the impeller 6 is an inverted cone shape, and the acceleration dispersion | distribution effect is anticipated.

  FIG. 4 shows an embodiment of the improved rotor blade of the rotor blade disperser of the present invention, and the cross-sectional shape of the blade 12 of the impeller 6 is a lower triangular shape. This is a difference from 3). The effect of making the blade 12 of the impeller 6 in the lower triangular shape in the present invention is to increase the process of the blade 12 colliding with the powder and to further expand the Taylor-Gertler vortex effect.

  FIG. 5 shows another embodiment of the improved rotor blade of the rotor blade disperser of the present invention, and the lower portion 17 of the blade 12 of the impeller 6 with respect to the basic configuration (FIG. 3) of the rotor blade disperser of the present invention. Is designed to provide a gap of about 2 to 20 mm between the curved portion of the bottom portion 13. As a result, it aims to improve the Taylor-Gertler vortex effect.

  FIG. 6 shows another embodiment of the dispersion cylinder of the rotor blade disperser according to the present invention. The shape of the dispersion cylinder 5 above the upper end of the impeller 6 is not a lower cone shape but a circular cross-sectional shape. It is characterized by achieving an accelerated dispersion effect. Others are the same as or similar to the structure and shape of the disperser of the present invention (FIGS. 3 to 5).

  FIG. 7 shows still another aspect of the dispersion cylinder of the rotary vane type disperser of the present invention. A plurality of protrusions are provided on the upper inverted conical shape portion or the circular cross-sectional shape portion of the dispersion cylinder 5 so that the gas and powder 3 The mixed flow is disturbed, and the dispersion effect of the powder 3 and the effect of preventing the adhesion of the powder to the inverted conical shape portion or the circular cross-sectional shape portion are generated. The thickness of the protrusion is a cylinder about 1/100 to 10 times as large as the median diameter of the three powder particles. The height of the cylinder is about 10 mm, and the interval between the cylinders is about 100 mm.

  The configuration of the powder dispersing apparatus as in the present invention can be applied and used in various fields. Here, some examples will be described.

1) Adjusting the particle size of the powder In the dry classification process that adjusts the particle size of food materials, toners, powder coating materials, glass production materials, electronic materials, etc., the powder as the feed material must be well dispersed and aerosolized. Absorption is very poor and powder aerosolization is an indispensable technology.

2) Detoxification of combustion exhaust gas Hazardous acidic gas generated in the incineration process such as household waste is rendered harmless by slaked lime flue jet and discharged as clean exhaust gas. It is also used to remove hydrogen chloride (substance that is the source of dioxins) and sulfur oxides. At this time, in order to effectively perform the detoxification reaction, it is necessary to disperse and aerosolize slaked lime well and to inject the flue.

3) Detoxification of soil contamination Slaked lime has a disinfecting effect and is also used for disinfecting soil contamination and bacterial infections (bird flu, etc.) due to water damage. A disperser increases its effectiveness and helps to disperse efficiently.

4) Reproduction of work environment and risk assessment In the risk investigation / research conducted by reproducing and simulating the work environment handling powder, it is necessary to make powder aerosol with adjusted dispersion strength.

5) Wear resistance test of equipment In order to investigate the durability of various equipment including automobiles and robots against dust, it is necessary to generate sand by dispersing aerosol.

6) Model experiment for environmental impacts Model experiments for predicting and investigating environmental distributions by simulating suspended particulates such as PM2.5 and radioactive aerosols require dispersion aerosolization of powder.

7) Others Performance tests of gas purification equipment such as automotive air cleaners, ventilation / air-conditioning filters, dust masks, industrial dust collectors / dust removers, etc. Verification of measuring equipment for powder and dust such as particle size distribution measuring equipment, pneumoconiometer ,Proofreading.

8) Nuclear power plant In a nuclear power plant, a filter for removing radioactive particles contained in the generated exhaust gas needs to generate fine particles of the same particle and similar diameter as an aerosol. This aerosol generator For example, it is necessary to generate aerosols with reliable particle dispersion.

1. . . Powder feeder 1. . . 2. Rotary blade disperser . . Powder 4. . . 4. Powder supply pipe . . Dispersion cylinder 6. . . Impeller 7. . . Aerosol discharge tube 8. . . Aerosol 9. . . Motor 10. . . Pulley 11. . . Bet 12. . . Feather 13. . . Bottom 14. . . Upper part 15. . . Pulley shaft 16. . . Protrusion 17. . . Lower part of the blade 12 18. . . Bypass inlet

Claims (5)

  It consists of a powder feeder 1 and a powder disperser 2 for dispersing the powder, and the powder falls from the powder feeder 1 through the powder supply pipe 4 to the dispersion cylinder 5 of the powder disperser 2. Then, in the powder dispersing apparatus in which the blade 12 of the impeller 6 at the bottom 13 of the dispersion cylinder 5 is discharged from the aerosol discharge pipe 7 as a swirling vortex, the dispersion cylinder 5 and the bottom 13 corresponding to the lower end equivalent part of the impeller 6 constitute a curved shape. A powder dispersion apparatus characterized by that.   The powder dispersion apparatus according to claim 1, wherein the shape of the dispersion cylinder above the upper end equivalent portion of the impeller (6) is an inverted conical shape or an inverted circular cross-sectional shape.   3. The powder dispersing apparatus according to claim 2, wherein the lower part of the cross-sectional shape of the blade 12 of the impeller 6 has a triangular shape.   The powder dispersing apparatus according to any one of claims 1 to 3, wherein a gap between the lower end of the blade 12 of the impeller 6 and the curved bottom portion 13 can be about 5 to 20 mm.   A protrusion having a thickness of about 1/100 to 10 times the median diameter of the number of particle diameters of the powder 3 is provided on the inverted conical shape portion or the inverted circular cross-sectional shape portion of the dispersion cylinder 5. Item 5. A powder dispersion apparatus according to Item 3 or 4.

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