JP3154547U - Spray coater - Google Patents

Abstract

Disclosed is a spray-type coating apparatus that has a simple internal structure and can be misted even when the inner diameter of a discharge nozzle for discharging a coating agent is increased. A spray-type coating device includes a discharge nozzle for discharging a slurry-like coating agent, two slit-type air nozzles for ejecting air, and a coating agent and a slit discharged from the discharge nozzle. A cylindrical casing 7 in which a mixed fluid composed of air jetted from the air nozzle 6 circulates and a cylindrical mist generating pipe 8 that generates mist from the mixed fluid of the coating agent and air are provided. [Selection] Figure 2

Description

  The present invention relates to a spray-type coating apparatus, and more particularly, to a spray-type coating apparatus used in the fields of coating industry, metal surface treatment industry, food industry, and the like.

  2. Description of the Related Art Conventionally, spray devices that prevent nozzle clogging and aim at uniform spraying have been provided. For example, in order to spray a liquid in a conical shape with one fluid nozzle, a spray nozzle having a rotator disposed in a vortex chamber in a spray nozzle body is provided. However, when the liquid flowing into the vortex chamber is in a slurry state, clogging occurs at the rotator portion.

  Therefore, Patent Document 1 discloses a spray nozzle that can be used with minimal clogging when spraying a slurry-like fluid without using a rotator. Patent Document 2 also discloses a spray nozzle that does not use a rotator. This spray nozzle has an axis that is eccentric, and the peripheral wall of the nozzle hole has a curved surface that gradually expands from the side of the swirl chamber.

JP 2000-254556 A JP-A-7-163915

  However, the nozzle described in Patent Document 1 cannot completely prevent clogging inside the nozzle because the flow path inside the nozzle is bent a plurality of times. In addition, in the spray nozzle described in Patent Document 2, in order to generate mist having an average particle size of 500 μm or less, the inner diameter of the nozzle needs to be about 2 mm. Can not. As described above, the conventional spray nozzle has a problem in that the internal structure of the nozzle is complicated and the inner diameter of the nozzle is small, so that clogging is likely to occur. When the inner diameter of the nozzle is increased for the purpose of preventing clogging, it becomes difficult to generate mist.

  The present invention was made to solve such problems. A spray-type coating device that has a simple internal structure and can be misted even when the inner diameter of the discharge nozzle for discharging the coating agent is increased. The purpose is to provide.

A spray type coating apparatus according to the present invention includes a discharge nozzle for discharging a coating agent, a plurality of slit type air nozzles for injecting air along an outer surface of the discharge nozzle, the coating agent discharged from the discharge nozzle, and the A casing through which a fluid mixture with air circulates and a mist generating pipe for generating mist from the mixed fluid that has circulated through the casing, and the mixed fluid that has circulated through the casing collides with an inner wall of the mist generating pipe. .
The inner diameter of the discharge nozzle is 2 mm or more and 10 mm or less.
The plurality of slit type air nozzles are arranged behind the discharge port of the discharge nozzle.
Two slit-type air nozzles are provided, and each slit-type air nozzle is disposed so as to sandwich the discharge nozzle at a position where the distance from the discharge port of the discharge nozzle is the same. The same angle is formed in the range of 30 ° to 75 ° with respect to the discharge direction axis of the nozzle.
The discharge nozzle axis of the discharge nozzle forms an angle of 15 ° to 60 ° with respect to the longitudinal axis of the mist generating tube.
The ratio of the flow rate of the coating agent discharged from the discharge nozzle to the flow rate of compressed air injected from the plurality of slit type air nozzles is 0.001 to 0.01.

  According to this device, the mixed fluid of the coating agent discharged from the discharge nozzle and the compressed air sprayed from the slit type air nozzle collides with the inner wall of the mist generating tube, and the bounced droplet is made mist with the compressed air and sprayed. Therefore, uniform mist can be generated. As a result, the internal structure becomes simple, and mist can be achieved even if the inner diameter of the discharge nozzle is increased.

It is a figure which shows the structure of the spray-type application | coating lubrication processing system using the spray-type application | coating apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the spray type coating device which concerns on this embodiment. It is a side view which shows arrangement | positioning of the discharge nozzle and slit type air nozzle of the spray type coating device which concerns on this embodiment. It is a figure which shows the structure of the slit type air nozzle of the spray type coating device which concerns on this embodiment. It is sectional drawing which shows the use condition of the spray type coating device which concerns on this embodiment. It is the schematic which shows the structure of the application | coating lubrication processing system used for the comparative example 1.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows the configuration of a spray coating lubrication processing system using a spray coating apparatus according to an embodiment of the present invention. The spray-type coating lubrication processing system 1 includes a coating booth 3 in which a member to be coated, for example, a steel bar 2 moves in the direction of arrow A, and two spray-type coating devices for supplying a mist of coating agent into the coating booth 3. 4 and 4.

As shown in FIG. 2, the spray-type coating device 4 includes a discharge nozzle 5 having an inner diameter of 6.5 mm from which a slurry-like coating agent is discharged, two slit-type air nozzles 6 and 6 for injecting air, and a discharge nozzle. A cylindrical casing 7 in which a mixed fluid composed of the coating agent discharged from 5 and air jetted from the slit type air nozzle 6 flows, and a cylindrical mist generating tube 8 for generating mist from the mixed fluid of coating agent and air. And. Discharge port 5a of the discharge nozzle 5 is inserted from one end portion 7a of the casing 7 while located in the center of the circular cross section of the casing 7 internally, a longitudinal axis of the discharge nozzle 5, i.e. a discharge axis L _1, It coincides with the longitudinal axis L _{2 of the} casing 7. The other end 7 b of the casing 7 is inserted into the inside from one end 8 a of the mist generating tube 8, and the longitudinal axis L ₂ of the casing 7 is relative to the hand direction axis L ₃ of the mist generating tube 8. The angle is 20 °. However, this angle is not limited to 20 ° and can be changed within a range of 15 ° to 60 °.

As shown in FIG. 3, the two slit type air nozzles 6, 6 are arranged so as to sandwich the discharge nozzle 5 at the same distance from the discharge port 5 a of the discharge nozzle 5. That is, the two slit-type air nozzles 6 and 6 are arranged behind the discharge port 5a when the direction in which the coating agent is discharged from the discharge port 5a is defined as the front. The ejection direction axis L ₄ of each slit type air nozzle 6 forms an angle of 45 ° with respect to the ejection direction axis L ₁ of the ejection nozzle 5. However, this angle is not limited to 45 °, and can be changed in a range of 30 ° to 75 °. It is preferable that the angles of the slit type air nozzles 6 are the same as each other.

  As shown in FIG. 4, the slit type air nozzle 6 includes a supply pipe 11 connected to an air supply source (not shown), a rectifying box 12 communicating with the supply pipe 11 through a hole 12a, and a nozzle portion for injecting air. 13. The nozzle portion 13 is configured such that a space 17 having a width of 0.3 mm is formed between the inner plate 14 and the outer plate 15 with a spacer 16 interposed therebetween. The inner plate 14 and the outer plate 15 are formed with a semicircular fitting recess 19 so that the discharge nozzle 5 (see FIG. 3) can be fitted, and the opening 18 communicating with the space 17 is fitted. It is provided along the recess 19. The rectifying box 12 is fixed to the inner plate 14 so that the hole 14a formed in the inner plate 14 and the hole 12b formed in the rectifying box 12 overlap, and the rectifying box 12 is connected to the rectifying box 12 via the holes 12b and 14a. The interior and the space 17 are in communication.

Next, the operation of the spray coating lubrication processing system using the spray coating apparatus according to this embodiment will be described.
As shown in FIG. 5, the slurry-like coating agent is discharged from the discharge nozzle 5 at a flow rate of 3 L / min. At the same time, compressed air is injected from the two slit type air nozzles 6 and 6 at a flow rate of 800 NL per minute in total. That is, the ratio of the flow rate of the coating agent discharged from the discharge nozzle 5 to the flow rate of the compressed air injected from the two slit type air nozzles 6 and 6 is 3.75 × 10 ⁻³ . In addition, although the value of each flow volume is not limited to the said value, Although it can change according to the magnitude | size of the spray type coating device 4, an application condition, etc., the value of the said ratio is 0.001-0.01. A range is preferable.

  As shown in FIG. 4B, compressed air from an air supply source (not shown) flows through the supply pipe 11 and then flows into the rectifying box 12 through the hole 12a. The compressed air in the rectification box 12 flows into the space 17 through the holes 12b and 14a and is injected from the opening 18. Since the width of the space 17 is 0.3 mm, the flow rate of the compressed air injected from the opening 18 is 50 m / second or more. In addition, the flow volume (flow velocity) of the compressed air injected from each slit type air nozzle 6 is the same.

As shown in FIG. 3, since the injection direction axis L ₄ of each slit type air nozzle 6 forms an angle of 45 ° with respect to the discharge direction axis L _{1 of the} discharge nozzle 5, it is injected from each slit type air nozzle 6. The compressed air flows toward the front in the discharge direction axis L ₁ along the outer peripheral surface of the discharge nozzle 5 while mixing with each other. When the compressed air passes through the discharge port 5a, it is mixed with the coating agent discharged from the discharge port 5a to become a mixed fluid. The mixed fluid includes droplets and liquid masses having various particle sizes.

As shown in FIG. 5, the mixed fluid flows through the casing 7 and then flows into the mist generating pipe 8. Here, since the longitudinal direction axis L ₂ of the casing 7 forms an angle of 25 ° with respect to the hand direction axis L ₃ of the mist generating tube 8, mist is generated from the mixed fluid flowing into the mist generating tube 8. A liquid mass or a droplet having a small particle diameter that scatters while diffusing in the tube 8 collides with the inner wall of the mist generating tube 8 and rebounds. The rebounded liquid mass and droplets are refined by the shearing action of compressed air to become mist, and the mist is carried by the air current and discharged from the mist generating tube 8. On the other hand, of the mixed fluid, a liquid mass that does not scatter or a droplet having a large particle diameter does not become mist, flows in the liquid state along the inner wall of the mist generating tube 8, and is discharged from the mist generating tube 8.

  As shown in FIG. 1, the mist discharged from the mist generating pipe 8 diffuses inside the coating booth 3 and uniformly adheres to the surface of the steel bar 2 moving in the direction of arrow A inside the coating booth 3. Thus, the coating agent is uniformly applied to the surface of the steel bar 2. On the other hand, the liquid mass that has not become mist or large-diameter droplets is discharged from the mist generating tube 8 and then collected at the bottom of the coating booth 3 and is not applied to the surface of the bar 2.

  Thus, the mixed fluid of the coating agent discharged from the discharge nozzle 5 and the compressed air sprayed from the slit type air nozzles 6 and 6 collides with the inner wall of the mist generating tube 8, and the bounced droplets are misted with the compressed air. Therefore, uniform mist can be generated. As a result, the internal structure becomes simple and mist can be achieved even if the inner diameter of the discharge nozzle 5 is increased.

  In this embodiment, the inner diameter of the discharge nozzle 5 is 6.5 mm, but it is not limited to 6.5 mm. The inner diameter of 2.0 mm described as the prior art may be used. Further, if the inner diameter is too large, mist formation becomes difficult even with the shearing action of compressed air, so the maximum value of the inner diameter is preferably about 10 mm. Therefore, the inner diameter of the discharge nozzle 5 may be 2.0 to 10 mm.

  In order to prevent the solid component of the coating agent from adhering to the inner walls of the discharge nozzle 5, the slit type air nozzle 6 and the mist generating tube 8, a non-adhesive surface treatment such as a fluororesin coating is applied to the metal surface. Is effective. It is also effective to use a resin pipe such as a fluororesin for the discharge nozzle 5.

  Next, the effect of reducing clogging of the discharge nozzle in the spray type coating apparatus according to the present invention was confirmed by examples. The coating agent used in the following Examples 1 and 2 and Comparative Examples 1 and 2 is a one-step lubricant FL-E900 manufactured by Nippon Parkerizing Co., Ltd., the present applicant. This coating agent is a lubricant for cold forging of a metal material, and is a coating type lubricant used for cold forging of automobile parts and bolts or wire drawing of a wire. Since this coating agent contains a solid content as a lubricating component, as will be understood from Comparative Examples 1 and 2 described later, when the coating agent is applied with a conventional spray nozzle, nozzle clogging occurs in a short time.

[Example 1]
Lubricant FL-E900 was apply | coated to the carbon steel (phi) 43 steel bar which is a to-be-coated material using the spray type application | coating lubrication processing system shown by FIG. The moving speed of the steel bar during coating was 20 m / min. Table 1 summarizes the test conditions and the presence or absence of clogging of the discharge nozzle.

  As understood from Table 1, even when the lubricant FL-E900 was applied to the material to be coated in the spray coating lubrication processing system according to the present invention, clogging of the discharge nozzle did not occur.

[Comparative Example 1]
As shown in FIG. 6, a two-fluid pressure type nozzle type 10535-1 manufactured by Spraying System Japan Co., Ltd. is provided with the same interval around the longitudinal direction of the carbon steel φ11.1 steel bar which is the material to be coated 50. The lubricant FL-E900 was applied to the material to be coated 50 using a system in which three / 4J injection nozzles 51 were provided. The moving speed of the material to be coated 50 during coating was 60 m / min. Table 2 summarizes the test conditions and the presence or absence of clogging of the injection nozzle 51.

  From Table 2, it can be seen that when the lubricant FL-E900 is applied with a conventional spray nozzle, clogging of the nozzle occurs.

[Example 2]
With the spray-type coating device 4 of the present invention, continuous injection of the lubricant FL-E900 was performed, and the time during which the discharge nozzle 5 was clogged was measured. Table 3 summarizes the test conditions and the presence or absence of clogging of the discharge nozzle.

  As understood from Table 3, even when the lubricant FL-E900 was sprayed by the spray type coating apparatus 4 according to the present invention, the discharge nozzle was not clogged.

[Comparative Example 2]
The continuous injection of the lubricant FL-E900 was performed with a full cone nozzle / Clogging elimination type AJP 1 / 2M manufactured by Ikeuchi Co., Ltd., and the time during which the discharge nozzle 5 was clogged was measured. The material of the nozzle is SCS13. Table 4 summarizes the test conditions and the presence or absence of clogging of the discharge nozzle.

  From Table 4, it is understood that when the lubricant FL-E900 is sprayed with a conventional spray nozzle, the nozzle is clogged in a short time.

4 spray type coating device, 5 discharge nozzle, 5a (discharge nozzle) discharge port, 6 slit type air nozzle, 7 casing, 8 mist generating pipe, L ₁ (discharge nozzle) discharge direction axis, L ₃ (mist generating pipe ) Longitudinal axis, L ₄ (slit air nozzle) jet direction axis.

Claims (6)

A discharge nozzle for discharging the coating agent;
A plurality of slit type air nozzles for injecting air along the outer surface of the discharge nozzle;
A casing through which a mixed fluid of the coating agent discharged from the discharge nozzle and the air flows;
A mist generating pipe for generating mist from the mixed fluid flowing through the casing,
The spray-type coating device, wherein the mixed fluid flowing through the casing collides with an inner wall of the mist generating pipe.   The spray-type coating device according to claim 1, wherein an inner diameter of the discharge nozzle is 2 mm or more and 10 mm or less.   The spray-type coating device according to claim 1 or 2, wherein the plurality of slit type air nozzles are arranged behind a discharge port of the discharge nozzle. With two slit air nozzles,
Each slit type air nozzle is disposed so as to sandwich the discharge nozzle at a position where the distance from the discharge port of the discharge nozzle is the same, and the ejection direction axis of each slit type air nozzle is relative to the discharge direction axis of the discharge nozzle. The spray-type coating device according to any one of claims 1 to 3, which forms the same angle in a range of 30 ° to 75 °.   The spray-type coating device according to any one of claims 1 to 4, wherein a discharge direction axis of the discharge nozzle forms an angle of 15 ° to 60 ° with respect to a longitudinal axis of the mist generating tube.   The ratio of the flow rate of the coating agent ejected from the ejection nozzle to the flow rate of compressed air ejected from the plurality of slit type air nozzles is 0.001 to 0.01. The spray type coating apparatus according to item.

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