JP2013111514A - Spraying apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spraying apparatus for preventing liquid dripping of a raw material to an object to be coated and improving utilization efficiency of the raw material.SOLUTION: The spraying apparatus 10 includes: a spray nozzle 21 where a spraying port 22 for spraying a raw material is formed; and a surrounding cover 31 which has an inner wall 35 arranged so as to surround the raw material sprayed from the spraying port 22 and extends in the direction of separating from the spraying port 22. On the surrounding cover 31, a gas jetting port 37 which is opened to the inner wall 35 and jets a purge gas is formed. The spraying apparatus 10 further includes an inclined plate 41 that is provided on the surrounding cover 31 and changes the flow of the purge gas jetted from the gas jetting port 37 to a direction along the inner wall 35.

Description

  The present invention generally relates to a spray spraying device, and more particularly to a spray spraying device including a cover body provided so as to surround a raw material sprayed from a nozzle.

  Regarding a conventional spraying device, for example, Japanese Patent Application Laid-Open No. 2011-563 discloses a paint that is provided with a minimum necessary capital investment without a large capital investment and adhered to a guide tube or the like used for suction. Paint mist and VOC gas (vaporized gas of volatile organic compounds) for the purpose of promoting the introduction to factories such as small and medium-sized enterprises without deteriorating the working environment due to mist, pipe clogging, and increasing maintenance burden ) A guidance device is disclosed (Patent Document 1).

  The paint mist and the VOC gas induction device disclosed in Patent Document 1 are disposed at a position facing the spray gun with the work sandwiched between the spray gun that sprays the paint toward the work, and did not collide with or adhere to the work. And a mist catcher for sucking the paint.

  Japanese Patent Application Laid-Open No. 6-190308 discloses a spray device that is a simple device but has a coating efficiency of approximately 100% and mist scattering of 0% ( Patent Document 2).

  The spray spray device disclosed in Patent Document 2 includes a trumpet-shaped cover body having a widened tip, a spray gun attached to a closed base end portion of the cover body, and a cylinder formed at the open end of the cover body. And a fitting cylinder fitted to the skirt. An annular air tube is fixed to the entire outer periphery of the fitting cylinder. In the annular air tube, a large number of air jets are formed at predetermined intervals, and an air curtain is formed in the extending direction of the cover body.

JP 2011-563 A JP-A-6-190308

As disclosed in the above-mentioned patent documents, spray spray apparatuses are widely used as thick film or thin film formation, cooling, and other means. The main points of the spray atomizer include the following points.
(1) Spraying is possible regardless of the type of raw material. Since spraying is possible from aqueous and organic materials to raw materials with high viscosity, the application field is wide.
(2) The device has a simple structure. Moreover, since there are few parameters for spraying the raw material, it is easy to use and the burden of maintenance is small. For this reason, a low-cost apparatus can be realized.
(3) Since the raw material is sprayed from the nozzle at a very high speed, it is less affected by the flow of airflow around the raw material and can reach the target object to be coated at a high rate. For this reason, the utilization efficiency of a raw material can be improved.

On the other hand, the following point is mentioned as a main fault of a spraying apparatus.
(1) On the principle of atomizing a liquid at a high pressure, the spraying speed must be increased to some extent. This is an advantage for certain fields, but it can also be a drawback in that the control range such as spray rate is limited.
(2) Generally, since the opening area of the spray port provided in the nozzle is very small, when spraying a raw material with a high viscosity or a solute that may precipitate, the spray port may be clogged. is there.
(3) Liquid dripping may occur from the spray port provided in the nozzle.
(4) Since the spray form of the raw material is basically radial, another mechanism is required when adjusting the spray form according to the object to be coated. In addition, when another mechanism is added, in consideration of the high spraying speed of the raw material, a mechanism with a certain amount of rectifying gas having a large size and a large flow rate is required. Further, since the spraying speed of the raw material decreases in inverse proportion to the square of the distance from the nozzle, it rapidly decreases as it moves away from the nozzle.

  Further explanation will be given in relation to the above drawbacks (1) and (4). When spraying the raw material toward the object to be coated in an open space as a spray spraying device, it did not adhere to the object to be coated by forming a flow of air supply and exhaust in a wide space including the object to be coated and the nozzle. There are those that collect droplets of raw materials. A typical example is a painting booth installed on a production line such as a car.

  In such a mechanism, the apparatus configuration becomes too large, and the utilization efficiency of raw materials is low. Accordingly, it is conceivable to improve the utilization efficiency of the raw material and prevent the raw material from scattering into the surrounding space by covering the periphery of the nozzle with a cover body. However, when a cover body is provided around the nozzle, adhesion of the raw material to the cover body becomes a problem. The smaller the cover body, the higher the utilization efficiency of the raw material, but the more the raw material adheres to the cover body. When the raw material adheres to the cover body frequently, there is a concern that the raw material drips on the object to be coated.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, and to provide a spray spraying device that prevents dripping of a raw material on an object to be coated and improves the utilization efficiency of the raw material.

  A spray spraying apparatus according to the present invention has a nozzle in which a spray port for spraying a raw material is formed and an inner wall arranged so as to surround the raw material sprayed from the spray port, and is in a predetermined direction away from the spray port. And a cover body extending in the direction. The cover body is formed with a gas injection port that opens to the inner wall and injects a purge gas. The spray device further includes a gas flow changing member that is provided in the cover body and changes the flow of the purge gas injected from the gas injection port in a direction along the inner wall.

  According to the spray spraying device configured as described above, it is possible to suppress the raw material from adhering to the cover body by the purge gas flowing along the inner wall of the cover body. Thereby, while preventing dripping of the raw material to a to-be-coated object, the utilization efficiency of a raw material can be improved.

  Preferably, a plurality of gas injection ports are formed in the cover body. The plurality of gas injection ports are arranged in a plane orthogonal to a predetermined direction in which the cover body extends away from the spray port. Preferably, a plurality of gas injection ports are formed in the cover body. The plurality of gas injection ports are arranged side by side in a predetermined direction in which the cover body extends away from the spray port.

  According to the spray spraying device configured as described above, the flow of the purge gas becomes a flatter flow with respect to the inner wall, so that it is difficult for the raw material to adhere to the entire cover body.

  Preferably, the cover body has an end portion which is disposed at a tip extending in a predetermined direction extending away from the spray port and faces an object to be coated with the raw material. The gas injection port is arranged in such a predetermined direction that the length between the gas injection port and the end is smaller than the length between the spray port and the gas injection port.

  According to the spray spraying device configured as described above, when the spray form of the raw material is radial, there is a concern that the raw material may adhere to the cover body, and the end of the cover body that faces the object to be coated rather than the spray port side of the nozzle. It becomes large on the part side. For this reason, it can prevent more reliably that a raw material adheres to a cover body by providing a gas injection port in the position nearer the edge part of a cover body.

  Preferably, the cover body has a hole extending in a predetermined direction toward the gas injection port and through which purge gas flows. According to the spray spraying device thus configured, the purge mechanism can be simply configured by providing the cover body itself with a hole for guiding the purge gas to the gas injection port.

  As described above, according to the present invention, it is possible to provide a spray spraying device that prevents dripping of a raw material on an object to be coated and improves the utilization efficiency of the raw material.

It is sectional drawing which shows the spraying apparatus in embodiment of this invention. It is sectional drawing which expands and shows the range enclosed by the dashed-two dotted line II in FIG. It is an expanded view which shows the enclosure cover in FIG. It is an expanded view which shows the 1st modification of the form by which a gas injection opening is formed in an enclosure cover. It is an expanded view which shows the 2nd modification of the form by which a gas injection opening is formed in an enclosure cover. It is a graph which shows the relationship between the number of stages of a purge mechanism, and source gas concentration.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

  FIG. 1 is a cross-sectional view showing a spraying apparatus according to an embodiment of the present invention. 2 is an enlarged cross-sectional view of a range surrounded by a two-dot chain line II in FIG.

  With reference to FIG. 1 and FIG. 2, the spraying apparatus 10 in this Embodiment is an apparatus for spraying a raw material on a to-be-coated object in the shape of a mist. In the figure, a substrate 100 is shown as a typical example of an object to be coated. The spray device 10 includes a spray nozzle 21, an enclosure cover 31, and a raw material supply device 12.

  The spray nozzle 21 is disposed to face the substrate 100. A spray port 22 is formed in the spray nozzle 21. The spray nozzle 21 is connected to the raw material supply device 12. The high-pressure raw material supplied from the raw material supply device 12 to the spray nozzle 21 is atomized and sprayed from the spray port 22.

  In the spray spraying apparatus 10 shown in FIG. 1, the spraying direction of the raw material from the spray nozzle 21 is vertically downward because the substrate 100 is disposed immediately below the spray nozzle 21. For example, the substrate 100 may be arranged at a position spaced apart from the spray nozzle 21 in the horizontal direction, and the spray direction of the raw material from the spray nozzle 21 may be set as the horizontal direction.

  The enclosure cover 31 is disposed around the spray nozzle 21. The enclosure cover 31 extends from the periphery of the spray nozzle 21 toward the substrate 100 in a cylindrical shape. As shown by an arrow 120 in FIG. 1, the enclosure cover 31 extends in a cylindrical shape in a direction away from the spray port 22 (hereinafter, the direction shown by the arrow 120 is also referred to as the axial direction of the enclosure cover 31). The enclosure cover 31 extends in a cylindrical shape from the spray port 22 of the spray nozzle 21 toward the substrate 100. The enclosure cover 31 has a cylindrical shape. A spray space 34 is formed inside the enclosure cover 31. The spray port 22 is positioned in the spray space 34.

  The enclosure cover 31 has an end portion 32 and an end portion 33. The end portion 32 and the end portion 33 are disposed at both ends of the enclosure cover 31 extending in a cylindrical shape. The end portion 33 is disposed to face the substrate 100. The enclosure cover 31 is provided so that a certain gap is formed between the substrate 100 and the end portion 33. The end portion 32 is disposed on the opposite side of the end portion 33 and on the front side of the end portion 33 as viewed from the spray nozzle 21.

  The enclosure cover 31 further includes an inner wall 35. The inner wall 35 is disposed so as to surround the raw material sprayed from the spray port 22. A spray space 34 is formed at a position surrounded by the inner wall 35. The inner wall 35 is formed as an inner peripheral surface of the enclosure cover 31 that extends between the end portion 32 and the end portion 33.

  At the time of coating the substrate 100, the raw material is sprayed into the spray space 34 from the spray port 22 in the form of mist (mist). The mist-like raw material spreads radially (umbrella shape) starting from the spray port 22, travels through the spray space 34, and adheres to the substrate 100 after that.

The spray device 10 further includes an exhaust cover 51 and a raw material recovery device 16.
The exhaust cover 51 is disposed on the outer periphery of the enclosure cover 31. An exhaust passage 52 is formed between the exhaust cover 51 and the enclosure cover 31. The exhaust passage 52 communicates with the raw material recovery device 16. At the time of coating the substrate 100, as shown by an arrow 130 in FIG. 1, an air flow is formed from the spray space 34 directly below the end portion 33 toward the exhaust passage 52. The raw material that has not adhered to the substrate 100 rides on the airflow, flows through the exhaust passage 52, and is recovered by the raw material recovery device 16.

  FIG. 3 is a development view showing the enclosure cover in FIG. 1. In the figure, a view in which the cylindrical enclosure cover 31 is developed in a planar shape and the inner wall 35 is viewed in plan is shown.

  With reference to FIGS. 1 to 3, the spray device 10 further includes an inclined plate 41 and a purge gas supply device 14. The enclosure cover 31 is formed with a gas injection port 37 that constitutes a purge mechanism together with the inclined plate 41 and a gas introduction hole 36 as a hole.

  The gas injection port 37 opens on the inner wall 35. A plurality of gas injection ports 37 are formed in the enclosure cover 31. The plurality of gas injection ports 37 are arranged at intervals in the circumferential direction of the inner wall 35. The plurality of gas injection ports 37 are arranged at equal intervals. As shown in FIG. 1, when a plane 110 orthogonal to the axial direction of the enclosure cover 31 is assumed, the plurality of gas injection ports 37 are arranged in the plane 110.

  In the gas injection port 37, the length H <b> 2 between the gas injection port 37 and the end portion 33 in the axial direction of the enclosure cover 31 is smaller than the length H <b> 1 between the spray port 22 and the gas injection port 37. (H2 <H1). That is, the gas injection port 37 is disposed closer to the end 33 of the enclosure cover 31 that faces the substrate 100 that is the object to be coated than the spray port 22 through which the raw material is sprayed.

  The gas introduction hole 36 extends in the axial direction of the enclosure cover 31 toward the gas injection port 37. The gas introduction hole 36 extends from the end portion 32 in the axial direction of the surrounding cover 31 and communicates with the gas injection port 37. A plurality of gas introduction holes 36 are respectively formed corresponding to the plurality of gas injection ports 37. The purge gas supply device 14 is connected to the gas introduction hole 36.

  In the present embodiment, since the gas introduction hole 36 opens at the end portion 32, the gas introduction portion such as a connector connected to the opening of the gas introduction hole 36 adversely affects the high-speed air flow of the raw material in the spray space 34. Can be avoided.

  The inclined plate 41 is provided on the enclosure cover 31. The inclined plate 41 is disposed so as to face the opening position of the gas injection port 37 in the inner wall 35. The inclined plate 41 is provided to be inclined with respect to the axial direction of the enclosure cover 31. The inclined plate 41 is inclined so that the distance from the inner wall 35 increases as the end portion 32 approaches the end portion 33. A plurality of inclined plates 41 are provided corresponding to the plurality of gas injection ports 37, respectively. The plurality of inclined plates 41 are arranged at intervals in the circumferential direction of the inner wall 35.

  The air supplied from the purge gas supply device 14 is injected into the spray space 34 as a purge gas from the gas injection port 37 through the gas introduction hole 36. The purge gas flows from the gas injection port 37 in the direction indicated by the arrow 135 in FIG. 2 and collides with the inclined plate 41. Due to the collision with the inclined plate 41, the flow direction of the purge gas is changed to a direction along the inner wall 35 as indicated by an arrow 140 in FIG.

  In the cross section shown in FIG. 2, the angle β at which the purge gas flow direction after collision with the inclined plate 41 (the direction indicated by the arrow 140) and the inner wall 35 intersect is the flow direction of the purge gas ejected from the gas injection port 37 (arrow). 135) and the inner wall 35 is smaller than an angle α (β <α). In the present embodiment, purge gas is injected from the gas injection port 37 in a direction orthogonal to the inner wall 35 (α = 90 °).

  According to such a configuration, an air curtain is formed on the surface of the inner wall 35 by the purge gas injected from the gas injection port 37. In the present embodiment, when the purge gas injected from the gas injection port 37 collides with the inclined plate 41, the gas pressure increases in the vicinity of the collision position. As a result, a uniform gas flow along the inclination direction of the inclined plate 41 is formed. Thereby, the raw material sprayed from the spray port 22 to the spray space 34 can be prevented from adhering to the enclosure cover 31.

  Further, the raw material sprayed from the spray port 22 spreads as it approaches the substrate 100 starting from the spray port 22 and advances in the spray space 34. For this reason, it is possible to more reliably prevent the raw material from adhering to the enclosure cover 31 by disposing the gas injection port 37 on the side close to the end portion 33 of the enclosure cover 31 facing the substrate 100.

  Further, in the present embodiment, the plurality of gas injection ports 37 are arranged in a plane 110 orthogonal to the axial direction of the enclosure cover 31. With such a configuration, it is possible to form a continuous air curtain along the circumferential direction of the inner wall 35, and avoid locally generating a region where the raw material adheres to the surrounding cover 31.

  In the present embodiment, the configuration in which the cylindrical enclosure cover 31 is provided around one spray nozzle 21 has been described. However, the present invention is not limited to this, and is arranged on, for example, a straight line. In addition, flat cover bodies may be provided on both sides of the plurality of spray nozzles 21.

  FIG. 4 is a development view showing a first modification of the form in which the gas injection port is formed in the enclosure cover. FIG. 5 is a development view showing a second modification of the form in which the gas injection port is formed in the enclosure cover.

  Referring to FIG. 4, in the present modification, a plurality of gas injection ports 37 are formed in multiple stages in the axial direction of surrounding cover 31. More specifically, the enclosure cover 31 is formed with a plurality of gas injection ports 37A and a plurality of gas injection ports 37B. Each of the plurality of gas injection ports 37 </ b> A and 37 </ b> B is provided in a plane 110 orthogonal to the axial direction of the enclosure cover 31. The plurality of gas injection ports 37 </ b> A and the plurality of gas injection ports 37 </ b> B are arranged in the axial direction of the enclosure cover 31.

  Referring to FIG. 5, in this modification, the plurality of gas injection ports 37 </ b> A and the plurality of gas injection ports 37 </ b> B are arranged so as to be shifted in the circumferential direction of the inner wall 35. Different from the example. The plurality of gas injection ports 37 are arranged in a staggered manner along the circumferential direction of the inner wall 35.

  4 and 5, the case where the purge mechanism is provided in two stages in the axial direction of the surrounding cover 31 has been described. However, the present invention is not limited to this, and a plurality of three or more stages is provided. A purge mechanism may be provided across the stages.

  FIG. 6 is a graph showing the relationship between the number of stages of the purge mechanism and the raw material gas concentration. Referring to FIG. 6, how much the concentration of the raw material gas is reduced in the vicinity of the inner wall 35 when the multistage purge mechanism is used was determined by fluid simulation. In this simulation, it is assumed that the source gas is water vapor, and the enclosure cover 31 is provided with 12 stages of purge mechanisms in the modification shown in FIG. In the figure, the number of stages of the purge mechanism is distributed in order from the side closer to the end portion 32.

  As can be seen from the graph in FIG. 6, the concentration of the raw material gas in the vicinity of the inner wall 35 becomes lower toward the downstream side away from the spray nozzle 21. In the 12-stage purge mechanism, the raw material gas concentration was reduced to about 37% of the concentration at the time of introducing the raw material.

  The structure of the spray spraying apparatus in the embodiment of the present invention described above will be described collectively. The spray spraying apparatus 10 in the present embodiment is a nozzle as a nozzle in which the spraying port 22 for spraying the raw material is formed. The spray nozzle 21 includes an inner cover 35 disposed so as to surround the raw material sprayed from the spray port 22, and an enclosure cover 31 as a cover body extending in a predetermined direction away from the spray port 22. The enclosure cover 31 is formed with a gas injection port 37 that opens to the inner wall 35 and injects a purge gas. The spray device 10 further includes an inclined plate 41 as a gas flow changing member that is provided in the enclosure cover 31 and changes the flow of the purge gas injected from the gas injection port 37 in the direction along the inner wall 35.

  According to the spray spraying apparatus 10 according to the embodiment of the present invention configured as described above, the raw material sprayed from the spray port 22 is made to function as the purge gas injected from the gas spray port 37 as an air curtain. It can prevent adhering to the enclosure cover 31. Accordingly, it is possible to prevent the raw material from dripping onto the substrate 100 and improve the utilization efficiency of the raw material.

  If the utilization efficiency of the raw material in the spray method is improved and the reduction of the adhesion rate of the raw material to the surroundings is realized, a product of high quality and low price can be realized. Addition of these to the original advantages of the spray method, such as the diversity of raw materials, the simplicity of the structure, and the ease of maintenance, there is a possibility that the use of the spray method may further spread to various industrial fields.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is used, for example, for food processing, painting, cooling mechanism, semiconductor wet process, and thin film formation.

  DESCRIPTION OF SYMBOLS 10 Spray spray apparatus, 12 Raw material supply apparatus, 14 Purge gas supply apparatus, 16 Raw material collection | recovery apparatus, 21 Spray nozzle, 22 Spray port, 31 Enclosure cover, 32, 33 edge part, 34 Spray space, 35 Inner wall, 36 Gas introduction hole, 37, 37A, 37B Gas injection port, 41 inclined plate, 51 exhaust cover, 52 exhaust passage, 100 substrate.

Claims (5)

A nozzle in which a spray port for spraying the raw material is formed;
A cover body having an inner wall arranged so as to surround the raw material sprayed from the spray port, and extending in a predetermined direction away from the spray port;
The cover body is formed with a gas injection port that opens to the inner wall and injects a purge gas,
A spraying device, comprising: a gas flow changing member that is provided on the cover body and changes a flow of purge gas injected from the gas injection port in a direction along the inner wall. The cover body is formed with a plurality of the gas injection ports,
The spray device according to claim 1, wherein the plurality of gas injection ports are arranged in a plane orthogonal to the predetermined direction. The cover body is formed with a plurality of the gas injection ports,
The spray device according to claim 1 or 2, wherein the plurality of gas injection ports are arranged side by side in the predetermined direction. The cover body is disposed at a tip extending in the predetermined direction, and has an end portion facing an object to be coated with a raw material,
The gas injection port is arranged such that a length between the gas injection port and the end portion is smaller than a length between the spray port and the gas injection port in the predetermined direction. Item 4. The spraying device according to any one of Items 1 to 3.   The spray device according to any one of claims 1 to 4, wherein the cover body is formed with a hole extending in the predetermined direction toward the gas injection port and through which purge gas flows.

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