JP2018184652A - Porcelain enamel coating device and porcelain enamel coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porcelain enamel coating method that prevents a coating film on a termination of an electric heating pin from peeling off therefrom.SOLUTION: There is provided a porcelain enamel coating method comprising: a pretreatment chamber 110 that pretreats a surface of a metal tube 10 as a fin tube for a heat exchanger having an electric heating pin 12 on its surface; a coating chamber in which the surface of the metal tube is coated with a porcelain enamel glaze supplied from a porcelain enamel glaze supplying nozzle 121 inside of the coating chamber 120 while feeding the metal tube; and a firing chamber in which the metal tube where coating is completed is fed into the firing chamber 130 to be fired. The method is further provided with a coating brush 122 that is placed at the front of the porcelain enamel glaze supplying nozzle and removes excessive porcelain enamel glaze and air bubbles from the surface of the metal tube, and is further provided with a termination coating unit 124 that coats the termination of the electric heating pin again with the porcelain enamel glaze before the metal tube enters into the firing chamber.SELECTED DRAWING: Figure 6

Description

  The present invention relates to an enamel coating apparatus and an enamel coating method, and more particularly to an enamel coating apparatus and an enamel coating method for coating the surface of a metal tube on which an electric heating pin is formed.

  Since metal tubes are often used in humid environments, various types of coatings are applied to the surface to improve durability.

  Like a fin tube used in a heat exchanger for a generator, the environment is poor (when the heat is exchanged using a gas containing an acid component in the generator, the surface of the tube and the electric heating pin are cooled while the gas is cooled) If the metal tube used in the fin tube is coated with a common coating composition, the corroded metal tube must be replaced periodically. There was a problem that it was inconvenient because it was not, and a lot of cost was required.

  Stainless steel and titanium metal tubes used as a solution to solve these problems are costly and only require a longer fin tube replacement cycle, which is a fundamental solution to acid corrosion. There is a limit that must not be. Furthermore, the Teflon (registered trademark) coating presented as another method has a problem in that it has a limit in terms of heat resistance.

  Since the enamel coating has a strong acid resistance characteristic, it is preferable to apply the enamel coating to a metal tube used in a poor environment where heat resistance and acid resistance are required.

  However, the enamel is not widely used because the enamel coating process is difficult.

  In particular, since the enamel glaze is highly viscous, the enamel that has been stored in the glaze storage container is lowered in the direction of gravity and supplied to the metal tube, thereby coating the metal tube with a non-uniform concentration of enamel glaze. There is a problem that bubbles are formed on the surface of the metal tube.

  The removal of bubbles is an important step in determining the durability of the fin tube, and the prior art uses a coating brush to remove bubbles by sweeping the surface of the metal tube coated with enamel glaze and the electric heating pin. I was able to.

  However, when the coating brush enters deeply between the heating pins and sweeps from the surface of the metal tube body to the end of the heating pin, more enamel glaze is swept away toward the end of the heating pin, resulting in a thinner coating film. There was a problem that could come off.

  In addition, there still remains a problem that the highly viscous enamel glaze is not uniformly applied to the metal tube.

  In addition, there is a problem in that the enamel glaze adheres to the rotating surface of the transfer roller that transfers the metal tube while the enamel coated metal tube is being transferred. Since the transfer roller transfers the metal tube while continuing to rotate in a state where the enamel is not removed, the enamel adhering to the transfer roller may adhere to other parts of the metal tube. It was.

  Korean Patent No. 10-2014-0081257 is disclosed as a conventional coating apparatus and coating method to which the enamel coating is applied.

  The present invention has been devised to solve the above-described problems. By coating the end of the electric heating pin formed on the metal tube that has been subjected to the coating process again using a terminal brush, the electric heating pin is provided. The purpose is to prevent the coating film at the end of the film from being peeled off.

  Another object is to make the concentration of the enamel glaze coated on the metal tube uniform by providing a stirrer inside the glaze storage container for supplying enamel glaze and stirring the enamel glaze.

  Another object of the present invention is to remove the enamel glaze adhering to the transfer roller by providing a coating liquid removing plate in contact with the rotating surface of the transfer roller at the side or lower portion of the transfer roller.

  In the enamel coating method according to the present invention for realizing the above-described object, (a) a metal tube, which is a fin tube for a heat exchanger having an electric heating pin formed on the surface, is fed to a pretreatment chamber and the surface And (b) feeding the metal tube, which has been pretreated in the step (a), into the coating chamber and supplying the enamel with the enamel glaze supplied from the enamel nozzle provided inside the coating chamber. Coating the surface of the metal tube; and (c) feeding the metal tube, which has been coated in the step (b), into a firing chamber and firing the metal tube, and using the direction of travel of the metal tube as a reference. A coating brush is provided on the front of the glaze supply nozzle, and the front In step (b), the step of removing excess enamel glaze and bubbles from the surface of the metal tube by the coating brush is further performed, and a terminal coating part is provided before entering the firing chamber, and step (c). Prior to, the end of the electric heating pin can be coated once more with enamel glaze by the end coating portion.

  The terminal coating part may be a terminal brush coated with enamel glaze.

  A glaze storage container connected to the enamel glaze supply nozzle to supply the enamel glaze to the metal tube, and a stirrer for stirring the enamel glaze inside the glaze storage container, the step (b), The enamel mixture that is uniformly mixed by the agitator may be supplied to the metal tube through the enamel spray nozzle.

  In the enamel coating method, a conveyor for transferring the metal tube is provided with two or more transfer rollers, and the transfer roller rotates while supporting a lower portion of the metal tube to move the metal tube along the conveyor. It can be rotating and advancing.

  One or more coating liquid removal plates are provided on the side or lower portion of the transfer roller located between the coating chamber and the baking chamber, respectively, and are inclined with respect to the rotation surface of the transfer roller, and the transfer roller rotates. Then, the process may further include the step of removing the enamel adhering to the transfer roller by the end of the coating liquid removing plate contacting the rotation surface of the transfer roller.

  The coating liquid removing plate may be provided perpendicular to the rotation surface of the transfer roller.

  The transfer roller may be a bar having a circular cross section, having a small diameter at the center and gradually increasing in diameter toward both ends, and having a tapered main body.

  The transfer roller may be provided on an axis that forms an angle of 5 ° to 35 ° in a clockwise direction or a counterclockwise direction with respect to a transverse line perpendicular to the longitudinal direction of the conveyor.

  The enamel coating apparatus according to the present invention includes a pretreatment chamber for pretreating a surface by feeding a metal tube, which is a fin tube for a heat exchanger having an electric heating pin formed on the surface, and a metal tube after the pretreatment is completed. A coating chamber that coats the surface of the metal tube with a enamel glaze supplied from a enamel spray nozzle that is fed into the coating chamber and supplied inside the coating chamber, and a metal tube that has been coated is fed to the firing chamber. A enamel coating apparatus including a firing chamber for firing, wherein a coating that removes excess enamel glaze and bubbles from the surface of the metal tube on the front surface of the enamel spray nozzle on the basis of the traveling direction of the metal tube Brush is further provided, terminating the coating section the metal tube is again coated with the enamel glaze the end of the heating pin prior to entering the firing chamber may further be provided.

  The terminal coating part may be a terminal brush coated with enamel glaze.

  A stirrer for stirring the enamel glaze may be further provided in a glaze storage container connected to the enamel spray nozzle and supplying the enamel glaze to the metal tube.

  The conveyor for transferring the metal tube is provided with two or more transfer rollers, and the transfer roller rotates while supporting the lower part of the metal tube to rotate and advance the metal tube along the conveyor. possible.

  One or more coating liquid removal plates are provided on the side or lower portion of the transfer roller located between the coating chamber and the baking chamber, respectively, and are inclined with respect to the rotation surface of the transfer roller, and the transfer roller rotates. Then, the end of the coating liquid removing plate may come into contact with the rotating surface of the transfer roller, and the enamel adhering to the transfer roller may be removed.

  The coating liquid removing plate may be provided perpendicular to the rotation surface of the transfer roller.

  The coating liquid removing plate may be made of a metal having high heat resistance.

  The transfer roller may be a bar having a circular cross section, having a small diameter at the center and gradually increasing in diameter toward both ends, and having a tapered main body.

  The transfer roller may be provided on an axis that forms an angle of 5 ° to 35 ° in a clockwise direction or a counterclockwise direction with respect to a transverse line perpendicular to the longitudinal direction of the baking chamber conveyor.

  According to the enamel coating apparatus and enamel coating method according to the present invention, the end of the electric heating pin formed on the metal tube that has undergone the coating process is coated once again using an end brush, so that the coating film at the end of the electric heating pin is formed. Peeling can be prevented.

  Moreover, the concentration of the enamel glaze coated on the metal tube can be made uniform by providing an agitator inside the glaze storage container for supplying enamel glaze and stirring the enamel glaze.

  Further, a coating liquid removing plate is provided on the side or lower portion of the transfer roller so that when the transfer roller rotates, the enamel adhering to the transfer roller is removed by the coating liquid removing plate that contacts the rotating surface of the transfer roller. be able to.

1 is a view illustrating a fin tube to be coated by the enamel coating method of the present invention. The drawing which illustrated the enamel coating apparatus of this invention exemplarily. The figure which illustrated the structure (b) of the motor and roller contained in the infeed conveyor (a) and infeed conveyor of the enamel coating apparatus of this invention. The drawing which simplified and illustrated the section of the coating part of the enamel coating apparatus of the present invention. The figure which showed typically the coating chamber contained in the coating part of the enamel coating apparatus of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a hollow brush coating apparatus according to the present invention having a terminal brush. BRIEF DESCRIPTION OF THE DRAWINGS Drawing which illustrated schematically what the transfer roller was comprised in the enamel coating apparatus of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating a pretreatment chamber conveyor, a coating chamber conveyor, and a baking chamber conveyor provided with a transfer roller in the enamel coating apparatus of the present invention. The perspective view which illustrated the transfer roller used for the enamel coating apparatus of this invention. The perspective view which illustrated the transfer roller and coating liquid removal board which are used for the enamel coating apparatus of this invention. Sectional drawing which illustrated the transfer roller and coating liquid removal board which are used for the enamel coating apparatus of this invention.

  Hereinafter, a configuration and operation of a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  A hollow coating apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  The enamel coating apparatus according to an embodiment of the present invention includes a pretreatment chamber 110 that pretreats a surface of a coating target that is a conductor fed from the infeed conveyor 200, and a coating target that has been subjected to the pretreatment. When fed, a coating chamber 120 that coats the surface of the coating object with the enamel glaze supplied from the enamel spray nozzle 121 installed therein, and the coating object that has been coated is baked when fed. The end brush 124 further includes a coating unit 100 having a firing chamber 130 to perform, and coats the end of the coating object between the coating chamber 120 and the firing chamber 130 once more. Is Bei.

  The coating object may be a metal tube 10.

  Please refer to FIG. The metal tube 10 may be a heat exchanger fin tube having electric heating pins 12 formed on the surface thereof.

  Please refer to FIG. The metal tube 10 may be fed by an in-feed conveyor 200, may pass through the coating unit 100, and may be out-fed by an out-feed conveyor 300. The infeed conveyor 200 and the outfeed conveyor 300 may be supported by an infeed conveyor stand 210 and an outfeed conveyor stand (not shown).

  The metal tube 10 can be advanced while being rotated by a plurality of pairs of rotating rollers 230 and a motor 220 forming an angle.

  Please refer to FIG. In the infeed conveyor 200, the metal tube 10 may be transferred from the metal tube loading unit 240 to the metal tube loading unit 250 through the metal tube transfer unit 260 and continuously fed to the coating unit 100. .

  The configuration of the infeed conveyor 200 may be configured such that the outfeed conveyor 300 is outfed in the same manner.

  Please refer to FIG. The coating unit 100 includes the pretreatment chamber 110, the coating chamber 120, and the baking chamber 130.

  The pretreatment chamber 110 is a chamber in which a pretreatment process of the metal tube 10 is performed. The pretreatment process may be performed by a method commonly used in this field, such as a shot blast method, a sand blast method, or a grit blast method.

  It is also possible to pre-treat the metal tube by a wet pre-treatment that is usually used for metal pre-treatment. During wet pre-treatment, ultrasonic waves are generated in the pre-treatment solution to further remove foreign matter on the surface of the metal tube. It is also possible to employ a method for efficient removal.

In addition, the pretreatment chamber 110 includes a heating unit 111, and the heating unit 111 is used to heat the metal tube 10 at a high temperature of 300 ° C. to 500 ° C. for a short period of time so as to adhere to the surface of the metal tube 10 Methods of removing similar components can be used.
The heating means 111 may be an electric furnace, a plasma heat treatment furnace, a heavy oil furnace, a transit furnace, a gas furnace, a hydrogen heat treatment furnace, an induction heating furnace, etc., and the metal tube 10 performs a pretreatment process while rotating. Regardless of the shape of the heating means 111, it can be heated uniformly.

  In addition, the pretreatment chamber 110 may include a pretreatment chamber conveyor 400 that rotates and advances the metal tube 10.

  Please refer to FIG. The coating chamber 120 is a chamber in which a process of coating the metal tube 10 with enamel glaze is performed.

  The coating chamber 120 is provided with a enamel glaze supply nozzle 121 for supplying enamel glaze for coating the metal tube 10. A glaze storage container (not shown) is connected to the enamel glaze supply nozzle 121, and a stirrer (not shown) for stirring the enamel glaze may be provided inside the glaze storage container. The high-viscosity enamel glaze can be agitated by the operation of the agitator so that the enamel glaze is supplied to the metal tube 10 at a uniform concentration.

  In addition, the coating chamber 120 may further include a coating brush 122. Excess enamel glaze and bubbles on the surface of the metal tube 10 can be removed by bringing the coating brush 122 into contact with the surface of the metal tube 10 to which the enamel glaze has been applied. For this, the coating brush 122 may be provided in front of the enamel glaze supply nozzle 121 and in the rear of the air injection nozzle 123 based on the traveling direction of the metal tube 10.

  The coating chamber 120 may further include an air injection nozzle 123. The air injection nozzle 123 is provided in front of the enamel glaze supply nozzle 121 with reference to the traveling direction of the metal tube 10. The air injection nozzle 123 may inject air onto the surface of the metal tube 10 to remove excess enamel glaze and air bubbles on the surface of the metal tube 10, and to rapidly dry the coated enamel glaze. it can.

  In addition, the coating chamber 120 may include a coating chamber conveyor 500 that rotates and advances the metal tube 10.

  Please refer to FIG. The firing chamber 130 is a chamber for firing the metal tube 10 coated with the enamel glaze.

  Like the pretreatment chamber 110, the firing chamber 130 includes a heating unit 131, and the metal tube 10 can be heated and fired at a high temperature of 700 ° C. to 1100 ° C. through the heating unit 131.

  In addition, the baking chamber 130 may include a baking chamber conveyor 600 that rotates and advances the metal tube 10.

  Please refer to FIG. The end brush 124 may be disposed in the coating chamber 120 between the coating brush 122 and the air spray nozzle 123 so as to contact the end of the electric heating pin 12 of the metal tube 10. The end brush 124 has the enamel glaze attached thereto, and the end of the electric heating pin 12 can be coated with the enamel glaze again to prevent the coating film from being peeled off.

  Please refer to FIG. 7 and FIG. The infeed conveyor 200, the pretreatment chamber conveyor 400, the coating chamber conveyor 500, the firing chamber conveyor 600, and the outfeed conveyor 300 have a plurality of transfer rollers 270 that transfer while supporting the lower end of the metal tube 10. Can be provided.

  The transfer roller 270 has a constant angle (A, 5 ° to 35 °, preferably 10 ° to 30 °) in a clockwise direction or a counterclockwise direction with respect to a direction perpendicular to the traveling direction of the metal tube 10. It can be provided to rotate by power supplied directly or indirectly with respect to a tilted axis.

  Reference is also made to FIG. The transfer roller 270 may be a bar having a circular cross section, and may have a tapered shape with a small diameter at the center and a gradually increasing diameter toward both ends.

  The form and arrangement of the transfer roller 270 serve to rotate and advance the metal tube 10 when power for rotating the transfer roller 270 is applied. The angle of the shaft of the transfer roller 270 determines the rotation speed of the metal tube 10, and the taper shape of the transfer roller guides the metal tube that advances while rotating so as not to be detached from the transfer roller. Can play a role.

  Please refer to FIG. 10 and FIG. One or more coating liquid removing plates 272, 272 a, 272 b, and 272 c may be provided on the side or lower portion of the transfer roller 270 that transfers the metal tube 10 coated with the enamel glaze.

  Since the lower end of the metal tube 10 is supported by the transfer roller 270 and rotates and moves forward, the enamel 273 dropped from the metal tube 10 coated with the enamel glaze adheres to the rotation surface of the transfer roller 270. there is a possibility. Since the transfer roller 270 rotates continuously to transfer the metal tube 10, the enamel glaze 273 attached to the rotation surface of the transfer roller 270 is attached to the continuously fed metal tube 10. .

  The coating liquid removing plates 272, 272 a, 272 b, and 272 c serve to sweep out and remove the enamel glaze 273 adhering to the rotating surface of the transfer roller 270. When the transfer roller 270 rotates, the coating liquid removing plates 272, 272a, 272b, and 272c come into contact with the rotation surface of the transfer roller 270 to remove the enamel glaze 273.

  In order to perform the role, the coating liquid removing plates 272, 272 a, 272 b, and 272 c are disposed on the side or lower portion of the transfer roller 270 between the coating chamber 120 and the baking chamber 130. Inclined with respect to the plane of rotation. Said tilt angle may preferably be 90 °.

  The coating liquid removal plates 272, 272a, 272b, and 272c have end portions that are in contact with the rotation surface of the transfer roller 270, and the coating liquid removal plate 272 rotates the metal tube 10 regardless of the number. And must be placed in a position that does not impede advancement.

  In addition, the coating unit 100 may be made of a metal having high heat resistance so as not to be affected by the high temperature environment.

  In the present invention, when the metal tube 10 is connected to another metal tube 10 before feeding the metal tube 10 to the pretreatment chamber 110, a pretreatment process, a coating process, and a baking process are performed. The chamber conveyor 400, the coating chamber conveyor 500, and the baking chamber conveyor 600 may not be provided.

  That is, since the coating part 100 including the pretreatment chamber 110, the coating chamber 120, and the baking chamber 130 is compact as in the present invention, its length is very short compared to the length of the metal tube to be coated. In some cases, the metal tube 10 can be continuously rotated and advanced by the infeed conveyor 200 and the outfeed conveyor 300 without a separate conveyor.

  On the other hand, before feeding into the pretreatment chamber 110, the rear end portion of the metal tube 10 is connected to another metal tube 10, and the pretreatment process, the coating process, and the firing process are not performed. If the individual metal tubes 10 are individually coated, the pretreatment chamber conveyor 400 and the coating chamber conveyor 500 may be used in the pretreatment process, the coating process, and the baking process so that the individual metal tubes 10 have a rotating and advancing force. And one or more of the baking chamber conveyors 600 may be required.

  An enamel coating method according to an embodiment of the present invention will be described.

  First, a step of pretreating the surface by feeding the metal tube 10 having the electrothermal pins 12 formed on the surface thereof to the pretreatment chamber 110 is performed.

  The metal tube 10 is fed through the infeed conveyor 200 while being rotated, rotated and advanced through the pretreatment chamber conveyor 400, and heated through the heating means 111 inside the pretreatment chamber 110.

  Next, the metal tube 10 that has been pretreated is fed to the coating chamber 120 to coat the surface.

  The metal tube 10 is rotated and advanced through the coating chamber conveyor 500 and is coated with the enamel glaze within the coating chamber 120. The enamel glaze may be supplied from an enamel glaze supply nozzle 121.

  At this time, a stirrer (not shown) provided in a glaze storage container (not shown) connected to the enamel glaze supply nozzle 121 agitates the enamel glaze inside the glaze storage container to provide the enamel glaze. The process of making the concentration of the same may be included.

  In addition, the method may further include removing bubbles by using the coating brush 122 to sweep the surface of the coated metal tube 10 so that the enamel glaze is uniformly applied.

  Also, air is sprayed onto the surface of the coated metal tube 10 through the air spray nozzle 123 to remove excess enamel glaze and air bubbles on the surface of the metal tube 10 to quickly dry the coated metal tube 10. The process of proceeding to the step may be further included.

  In addition, the process may further include preventing the coating film from peeling off by coating the end of the electric heating pin 12 of the coated metal tube 10 with the enamel glaze again using the end brush 124.

  Also, a coating liquid removing plate 272 may be provided to remove the enamel glaze 273 separated from the coated metal tube 10 and attached to the transfer roller 270.

  Finally, the coated metal tube 10 is fed to the firing chamber 130 and fired while being rotated and advanced through the firing chamber conveyor 600, and then is fed out through the outfeed conveyor 300.

  As described above, the present invention is not limited to the above-described embodiments, but has ordinary knowledge in the technical field to which the invention belongs without departing from the technical idea of the present invention claimed in the scope of claims. Obvious modifications can be made by those skilled in the art, and such modifications are within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Metal tube 12 Electrothermal pin 100 Coating part 110 Pretreatment chamber 111 Heating means 120 Coating chamber 121 Enamel supply nozzle 122 Coating brush 123 Air injection nozzle 124 Termination brush 130 Firing chamber 131 Heating means 200 In-feed conveyor 210 In-feed conveyor stand 220 Motor 230 Rotating roller 240 Metal tube stacking unit 250 Metal tube loading unit 260 Metal tube transfer unit 270 Transfer roller 272 Coating solution removal plate 272a First coating solution removal plate 272b Second coating solution removal Plate 272c Third coating solution removal plate 273 Enamel 300 Out-feed (out-f ed) Conveyor 400 pretreatment chamber conveyor 500 coating chamber conveyor 600 firing chamber conveyor

The present invention relates to an enamel coating apparatus and an enamel coating method, and more particularly to an enamel coating apparatus and an enamel coating method for coating the surface of a metal tube on which heat transfer fins are formed.

  Since metal tubes are often used in humid environments, various types of coatings are applied to the surface to improve durability.

Like the fin tubes used in heat exchangers for generators, the environment and the heat transfer of the tubes while the gas is cooled when heat is exchanged using the gas containing acid components in the generator metal tube used in low temperature corrosion phenomenon occurs in the fin tube) by the fins is exposed to the acid dew點, when coated with conventional coating compositions, be replaced corrosion metal tube periodically It is inconvenient because it must be done, and there is a problem that requires a lot of cost.

  Stainless steel and titanium metal tubes used as a solution to solve these problems are costly and only require a longer fin tube replacement cycle, which is a fundamental solution to acid corrosion. There is a limit that must not be. Furthermore, Teflon (registered trademark) coating presented as another method has a problem in that it has a limit in heat resistance.

  Since the enamel coating has a strong acid resistance characteristic, it is preferable to apply the enamel coating to a metal tube used in a poor environment where heat resistance and acid resistance are required.

  However, the enamel is not widely used because the enamel coating process is difficult.

  In particular, since the enamel glaze is highly viscous, the enamel that has been stored in the glaze storage container is lowered in the direction of gravity and supplied to the metal tube, thereby coating the metal tube with a non-uniform concentration of enamel glaze. There is a problem that bubbles are formed on the surface of the metal tube.

Bubble removal is an important step in determining fin tube durability, and the prior art uses a coating brush to remove bubbles by sweeping the surface of metal tubes and heat transfer fins coated with enamel glaze. I was able to.

However, by sweeping the surface of the metal tube body to the end of the heat transfer fins coating brush deeply enters between the heat transfer fins, cause the enamel glaze toward the end of the heat transfer fins many swept been in, coated There was a problem that the film could be thinned or peeled off.

  In addition, there still remains a problem that the highly viscous enamel glaze is not uniformly applied to the metal tube.

  In addition, there is a problem in that the enamel glaze adheres to the rotating surface of the transfer roller that transfers the metal tube while the enamel coated metal tube is being transferred. Since the transfer roller transfers the metal tube while continuing to rotate in a state where the enamel is not removed, the enamel adhering to the transfer roller may adhere to other parts of the metal tube. It was.

  Korean Patent No. 10-2014-0081257 is disclosed as a conventional coating apparatus and coating method to which the enamel coating is applied.

The present invention has been devised to solve the above-described problems. By coating the end of the heat transfer fin formed on the metal tube that has undergone the coating process once again using a terminal brush, the heat transfer is performed. The purpose is to prevent the coating film at the end of the heat fin from being peeled off.

  Another object is to make the concentration of the enamel glaze coated on the metal tube uniform by providing a stirrer inside the glaze storage container for supplying enamel glaze and stirring the enamel glaze.

  Another object of the present invention is to remove the enamel glaze adhering to the transfer roller by providing a coating liquid removing plate in contact with the rotating surface of the transfer roller at the side or lower portion of the transfer roller.

In the enamel coating method according to the present invention for realizing the above-mentioned object, (a) a metal tube, which is a fin tube for a heat exchanger having a heat transfer fin formed on the surface, is fed to a pretreatment chamber. A step of pre-treating the surface, and (b) a metal powder which has been pre-treated in step (a) is fed into the coating chamber and supplied with a wax glaze supplied from the enamel nozzle provided in the coating chamber. Coating the surface of the metal tube; and (c) feeding the metal tube coated in the step (b) to a firing chamber and firing the metal tube, with the traveling direction of the metal tube as a reference. A coating brush is provided on the front of the enamel glaze supply nozzle, The step (b) further includes the step of removing excess enamel glaze and air bubbles from the surface of the metal tube by the coating brush, and a termination coating part is provided before entering the firing chamber. Prior to the step, the end of the heat transfer fin may be coated once more with enamel glaze by the end coating.

  The terminal coating part may be a terminal brush coated with enamel glaze.

  A glaze storage container connected to the enamel glaze supply nozzle to supply the enamel glaze to the metal tube, and a stirrer for stirring the enamel glaze inside the glaze storage container, the step (b), The enamel mixture that is uniformly mixed by the agitator may be supplied to the metal tube through the enamel spray nozzle.

  In the enamel coating method, a conveyor for transferring the metal tube is provided with two or more transfer rollers, and the transfer roller rotates while supporting a lower portion of the metal tube to move the metal tube along the conveyor. It can be rotating and advancing.

  One or more coating liquid removal plates are provided on the side or lower portion of the transfer roller located between the coating chamber and the baking chamber, respectively, and are inclined with respect to the rotation surface of the transfer roller, and the transfer roller rotates. Then, the process may further include the step of removing the enamel adhering to the transfer roller by the end of the coating liquid removing plate contacting the rotation surface of the transfer roller.

  The coating liquid removing plate may be provided perpendicular to the rotation surface of the transfer roller.

  The transfer roller may be a bar having a circular cross section, having a small diameter at the center and gradually increasing in diameter toward both ends, and having a tapered main body.

  The transfer roller may be provided on an axis that forms an angle of 5 ° to 35 ° in a clockwise direction or a counterclockwise direction with respect to a transverse line perpendicular to the longitudinal direction of the conveyor.

The enamel coating apparatus according to the present invention includes a pretreatment chamber for pretreating a surface by feeding a metal tube which is a fin tube for a heat exchanger having heat transfer fins formed on the surface, and a metal tube after the pretreatment is completed. The coating chamber that coats the surface of the metal tube with the enamel powder supplied from the enamel nozzle that is installed inside the coating chamber and the metal tube that has been coated is fed into the firing chamber. The enamel coating apparatus includes a firing chamber for firing, and a coating for removing excess enamel glaze and bubbles from the surface of the metal tube on the front surface of the enamel spray nozzle on the basis of the traveling direction of the metal tube. Guburashi is further provided, terminating the coating unit for coating again terminates in the enamel glaze of the heat transfer fins before said metal tube enters the firing chamber may further be provided.

  The terminal coating part may be a terminal brush coated with enamel glaze.

  A stirrer for stirring the enamel glaze may be further provided in a glaze storage container connected to the enamel spray nozzle and supplying the enamel glaze to the metal tube.

  The conveyor for transferring the metal tube is provided with two or more transfer rollers, and the transfer roller rotates while supporting the lower part of the metal tube to rotate and advance the metal tube along the conveyor. possible.

  One or more coating liquid removal plates are provided on the side or lower portion of the transfer roller located between the coating chamber and the baking chamber, respectively, and are inclined with respect to the rotation surface of the transfer roller, and the transfer roller rotates. Then, the end of the coating liquid removing plate may come into contact with the rotating surface of the transfer roller, and the enamel adhering to the transfer roller may be removed.

  The coating liquid removing plate may be provided perpendicular to the rotation surface of the transfer roller.

  The coating liquid removing plate may be made of a metal having high heat resistance.

  The transfer roller may be a bar having a circular cross section, having a small diameter at the center and gradually increasing in diameter toward both ends, and having a tapered main body.

  The transfer roller may be provided on an axis that forms an angle of 5 ° to 35 ° in a clockwise direction or a counterclockwise direction with respect to a transverse line perpendicular to the longitudinal direction of the baking chamber conveyor.

According to the enamel coating apparatus and enamel coating process according to the present invention, by coating again the end of the heat transfer fins formed in the metal tube through a coating process using the end brush, coating the end of the heat transfer fins Peeling of the film can be prevented.

  Moreover, the concentration of the enamel glaze coated on the metal tube can be made uniform by providing an agitator inside the glaze storage container for supplying enamel glaze and stirring the enamel glaze.

  Further, a coating liquid removing plate is provided on the side or lower portion of the transfer roller so that when the transfer roller rotates, the enamel adhering to the transfer roller is removed by the coating liquid removing plate that contacts the rotating surface of the transfer roller. be able to.

1 is a view illustrating a fin tube to be coated by the enamel coating method of the present invention. The drawing which illustrated the enamel coating apparatus of this invention exemplarily. The figure which illustrated the structure (b) of the motor and roller contained in the infeed conveyor (a) and infeed conveyor of the enamel coating apparatus of this invention. The drawing which simplified and illustrated the section of the coating part of the enamel coating apparatus of the present invention. The figure which showed typically the coating chamber contained in the coating part of the enamel coating apparatus of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a hollow brush coating apparatus according to the present invention having a terminal brush. BRIEF DESCRIPTION OF THE DRAWINGS Drawing which illustrated schematically what the transfer roller was comprised in the enamel coating apparatus of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating a pretreatment chamber conveyor, a coating chamber conveyor, and a baking chamber conveyor provided with a transfer roller in the enamel coating apparatus of the present invention. The perspective view which illustrated the transfer roller used for the enamel coating apparatus of this invention. The perspective view which illustrated the transfer roller and coating liquid removal board which are used for the enamel coating apparatus of this invention. Sectional drawing which illustrated the transfer roller and coating liquid removal board which are used for the enamel coating apparatus of this invention.

  Hereinafter, a configuration and operation of a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  A hollow coating apparatus according to an embodiment of the present invention will be described with reference to FIGS.

  The enamel coating apparatus according to an embodiment of the present invention includes a pretreatment chamber 110 that pretreats a surface of a coating target that is a conductor fed from the infeed conveyor 200, and a coating target that has been subjected to the pretreatment. When fed, a coating chamber 120 that coats the surface of the coating object with the enamel glaze supplied from the enamel spray nozzle 121 installed therein, and the coating object that has been coated is baked when fed. The end brush 124 further includes a coating unit 100 having a firing chamber 130 to perform, and coats the end of the coating object between the coating chamber 120 and the firing chamber 130 once more. Is Bei.

  The coating object may be a metal tube 10.

Please refer to FIG. The metal tube 10 may be a heat exchanger fin tube having heat transfer fins 12 formed on a surface thereof.

  Please refer to FIG. The metal tube 10 may be fed by an in-feed conveyor 200, may pass through the coating unit 100, and may be out-fed by an out-feed conveyor 300. The infeed conveyor 200 and the outfeed conveyor 300 may be supported by an infeed conveyor stand 210 and an outfeed conveyor stand (not shown).

  The metal tube 10 can be advanced while being rotated by a plurality of pairs of rotating rollers 230 and a motor 220 forming an angle.

  Please refer to FIG. In the infeed conveyor 200, the metal tube 10 may be transferred from the metal tube loading unit 240 to the metal tube loading unit 250 through the metal tube transfer unit 260 and continuously fed to the coating unit 100. .

  The configuration of the infeed conveyor 200 may be configured such that the outfeed conveyor 300 is outfed in the same manner.

  Please refer to FIG. The coating unit 100 includes the pretreatment chamber 110, the coating chamber 120, and the baking chamber 130.

  The pretreatment chamber 110 is a chamber in which a pretreatment process of the metal tube 10 is performed. The pretreatment process may be performed by a method commonly used in this field, such as a shot blast method, a sand blast method, or a grit blast method.

  It is also possible to pre-treat the metal tube by a wet pre-treatment that is usually used for metal pre-treatment. During wet pre-treatment, ultrasonic waves are generated in the pre-treatment solution to further remove foreign matter on the surface of the metal tube. It is also possible to employ a method for efficient removal.

In addition, the pretreatment chamber 110 includes a heating unit 111, and the heating unit 111 is used to heat the metal tube 10 at a high temperature of 300 ° C. to 500 ° C. for a short period of time so as to adhere to the surface of the metal tube 10 Methods of removing similar components can be used.
The heating means 111 may be an electric furnace, a plasma heat treatment furnace, a heavy oil furnace, a transit furnace, a gas furnace, a hydrogen heat treatment furnace, an induction heating furnace, etc., and the metal tube 10 performs a pretreatment process while rotating. Regardless of the shape of the heating means 111, it can be heated uniformly.

  In addition, the pretreatment chamber 110 may include a pretreatment chamber conveyor 400 that rotates and advances the metal tube 10.

  Please refer to FIG. The coating chamber 120 is a chamber in which a process of coating the metal tube 10 with enamel glaze is performed.

  The coating chamber 120 is provided with a enamel glaze supply nozzle 121 for supplying enamel glaze for coating the metal tube 10. A glaze storage container (not shown) is connected to the enamel glaze supply nozzle 121, and a stirrer (not shown) for stirring the enamel glaze may be provided inside the glaze storage container. The high-viscosity enamel glaze can be agitated by the operation of the agitator so that the enamel glaze is supplied to the metal tube 10 at a uniform concentration.

  In addition, the coating chamber 120 may further include a coating brush 122. Excess enamel glaze and bubbles on the surface of the metal tube 10 can be removed by bringing the coating brush 122 into contact with the surface of the metal tube 10 to which the enamel glaze has been applied. For this, the coating brush 122 may be provided in front of the enamel glaze supply nozzle 121 and in the rear of the air injection nozzle 123 based on the traveling direction of the metal tube 10.

  The coating chamber 120 may further include an air injection nozzle 123. The air injection nozzle 123 is provided in front of the enamel glaze supply nozzle 121 with reference to the traveling direction of the metal tube 10. The air injection nozzle 123 may inject air onto the surface of the metal tube 10 to remove excess enamel glaze and air bubbles on the surface of the metal tube 10, and to rapidly dry the coated enamel glaze. it can.

  In addition, the coating chamber 120 may include a coating chamber conveyor 500 that rotates and advances the metal tube 10.

  Please refer to FIG. The firing chamber 130 is a chamber for firing the metal tube 10 coated with the enamel glaze.

  Like the pretreatment chamber 110, the firing chamber 130 includes a heating unit 131, and the metal tube 10 can be heated and fired at a high temperature of 700 ° C. to 1100 ° C. through the heating unit 131.

  In addition, the baking chamber 130 may include a baking chamber conveyor 600 that rotates and advances the metal tube 10.

Please refer to FIG. The end brush 124 may be disposed in the coating chamber 120 between the coating brush 122 and the air injection nozzle 123 so as to contact the end of the heat transfer fin 12 of the metal tube 10. The end brush 124 has the enamel glaze attached thereto, and the end of the heat transfer fin 12 can be coated with the enamel glaze again to prevent the coating film from peeling off.

  Please refer to FIG. 7 and FIG. The infeed conveyor 200, the pretreatment chamber conveyor 400, the coating chamber conveyor 500, the firing chamber conveyor 600, and the outfeed conveyor 300 have a plurality of transfer rollers 270 that transfer while supporting the lower end of the metal tube 10. Can be provided.

  The transfer roller 270 has a constant angle (A, 5 ° to 35 °, preferably 10 ° to 30 °) in a clockwise direction or a counterclockwise direction with respect to a direction perpendicular to the traveling direction of the metal tube 10. It can be provided to rotate by power supplied directly or indirectly with respect to a tilted axis.

  Reference is also made to FIG. The transfer roller 270 may be a bar having a circular cross section, and may have a tapered shape with a small diameter at the center and a gradually increasing diameter toward both ends.

  The form and arrangement of the transfer roller 270 serve to rotate and advance the metal tube 10 when power for rotating the transfer roller 270 is applied. The angle of the shaft of the transfer roller 270 determines the rotation speed of the metal tube 10, and the taper shape of the transfer roller guides the metal tube that advances while rotating so as not to be detached from the transfer roller. Can play a role.

  Please refer to FIG. 10 and FIG. One or more coating liquid removing plates 272, 272 a, 272 b, and 272 c may be provided on the side or lower portion of the transfer roller 270 that transfers the metal tube 10 coated with the enamel glaze.

  Since the lower end of the metal tube 10 is supported by the transfer roller 270 and rotates and moves forward, the enamel 273 dropped from the metal tube 10 coated with the enamel glaze adheres to the rotation surface of the transfer roller 270. there is a possibility. Since the transfer roller 270 rotates continuously to transfer the metal tube 10, the enamel glaze 273 attached to the rotation surface of the transfer roller 270 is attached to the continuously fed metal tube 10. .

  The coating liquid removing plates 272, 272 a, 272 b, and 272 c serve to sweep out and remove the enamel glaze 273 adhering to the rotating surface of the transfer roller 270. When the transfer roller 270 rotates, the coating liquid removing plates 272, 272a, 272b, and 272c come into contact with the rotation surface of the transfer roller 270 to remove the enamel glaze 273.

  In order to perform the role, the coating liquid removing plates 272, 272 a, 272 b, and 272 c are disposed on the side or lower portion of the transfer roller 270 between the coating chamber 120 and the baking chamber 130. Inclined with respect to the plane of rotation. Said tilt angle may preferably be 90 °.

  The coating liquid removal plates 272, 272a, 272b, and 272c have end portions that are in contact with the rotation surface of the transfer roller 270, and the coating liquid removal plate 272 rotates the metal tube 10 regardless of the number. And must be placed in a position that does not impede advancement.

  In addition, the coating unit 100 may be made of a metal having high heat resistance so as not to be affected by the high temperature environment.

  In the present invention, when the metal tube 10 is connected to another metal tube 10 before feeding the metal tube 10 to the pretreatment chamber 110, a pretreatment process, a coating process, and a baking process are performed. The chamber conveyor 400, the coating chamber conveyor 500, and the baking chamber conveyor 600 may not be provided.

  That is, since the coating part 100 including the pretreatment chamber 110, the coating chamber 120, and the baking chamber 130 is compact as in the present invention, its length is very short compared to the length of the metal tube to be coated. In some cases, the metal tube 10 can be continuously rotated and advanced by the infeed conveyor 200 and the outfeed conveyor 300 without a separate conveyor.

  On the other hand, before feeding into the pretreatment chamber 110, the rear end portion of the metal tube 10 is connected to another metal tube 10, and the pretreatment process, the coating process, and the firing process are not performed. If the individual metal tubes 10 are individually coated, the pretreatment chamber conveyor 400 and the coating chamber conveyor 500 may be used in the pretreatment process, the coating process, and the baking process so that the individual metal tubes 10 have a rotating and advancing force. And one or more of the baking chamber conveyors 600 may be required.

  An enamel coating method according to an embodiment of the present invention will be described.

First, the metal tube 10 having the heat transfer fins 12 formed on the surface thereof is fed to the pretreatment chamber 110 to pretreat the surface.

  The metal tube 10 is fed through the infeed conveyor 200 while being rotated, rotated and advanced through the pretreatment chamber conveyor 400, and heated through the heating means 111 inside the pretreatment chamber 110.

  Next, the metal tube 10 that has been pretreated is fed to the coating chamber 120 to coat the surface.

  The metal tube 10 is rotated and advanced through the coating chamber conveyor 500 and is coated with the enamel glaze within the coating chamber 120. The enamel glaze may be supplied from an enamel glaze supply nozzle 121.

  At this time, a stirrer (not shown) provided in a glaze storage container (not shown) connected to the enamel glaze supply nozzle 121 agitates the enamel glaze inside the glaze storage container to provide the enamel glaze. The process of making the concentration of the same may be included.

  In addition, the method may further include removing bubbles by using the coating brush 122 to sweep the surface of the coated metal tube 10 so that the enamel glaze is uniformly applied.

  Also, air is sprayed onto the surface of the coated metal tube 10 through the air spray nozzle 123 to remove excess enamel glaze and air bubbles on the surface of the metal tube 10 to quickly dry the coated metal tube 10. The process of proceeding to the step may be further included.

In addition, the process may further include preventing the coating film from peeling off by coating the end of the heat transfer fin 12 of the coated metal tube 10 with the enamel glaze again using the end brush 124.

  Also, a coating liquid removing plate 272 may be provided to remove the enamel glaze 273 separated from the coated metal tube 10 and attached to the transfer roller 270.

  Finally, the coated metal tube 10 is fed to the firing chamber 130 and fired while being rotated and advanced through the firing chamber conveyor 600, and then is fed out through the outfeed conveyor 300.

  As described above, the present invention is not limited to the above-described embodiments, but has ordinary knowledge in the technical field to which the invention belongs without departing from the technical idea of the present invention claimed in the scope of claims. Obvious modifications can be made by those skilled in the art, and such modifications are within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Metal tube 12 Heat transfer fin 100 Coating part 110 Pretreatment chamber 111 Heating means 120 Coating chamber 121 Enamel supply nozzle 122 Coating brush 123 Air injection nozzle 124 Termination brush 130 Firing chamber 131 Heating means 200 In-feed conveyor 210 In-feed conveyor stand 220 Motor 230 Rotating roller 240 Metal tube stacking unit 250 Metal tube loading unit 260 Metal tube transfer unit 270 Transfer roller 272 Coating solution removal plate 272a First coating solution removal plate 272b Second coating solution Removal plate 272c Third coating solution removal plate 273 Enamel 300 Out-feed (out-f eed) Conveyor 400 Pretreatment chamber conveyor 500 Coating chamber conveyor 600 Firing chamber conveyor

Claims (17)

(A) a step of pretreating the surface by feeding a metal tube, which is a fin tube for a heat exchanger having an electric heating pin formed on the surface, to a pretreatment chamber;
(B) The metal tube that has been pretreated in the step (a) is fed to the coating chamber, and the surface of the metal tube is coated with the enamel glaze supplied from the enamel glaze supply nozzle installed in the coating chamber. Stages, and
(C) including a step of feeding the metal tube, which has been coated in the step (b), into a firing chamber and firing the tube.
A coating brush is provided on the front surface of the enamel spray nozzle with reference to the traveling direction of the metal tube. In the step (b), excess enamel glaze and bubbles are removed from the surface of the metal tube by the coating brush. Steps are further carried out,
A terminal coating part is provided before entering the baking chamber, and the terminal of the electric heating pin is coated once again with a wax glaze by the terminal coating part prior to the step (c).
Enamel coating method.   The enamel coating method according to claim 1, wherein the end coating part is an end brush coated with enamel glaze.   A glaze storage container connected to the enamel glaze supply nozzle to supply the enamel glaze to the metal tube, and a stirrer for stirring the enamel glaze inside the glaze storage container, the step (b), 2. The enamel coating method according to claim 1, wherein the enamel mixture uniformly mixed by the stirrer is supplied to the metal tube through the enamel spray nozzle.   The conveyor for transferring the metal tube includes two or more transfer rollers, and the transfer roller rotates while supporting a lower portion of the metal tube to rotate and advance the metal tube along the conveyor. 2. The enamel coating method according to claim 1, wherein   One or more coating liquid removal plates are provided on the side or lower portion of the transfer roller located between the coating chamber and the baking chamber, respectively, and are inclined with respect to the rotation surface of the transfer roller, and the transfer roller rotates. 5. The enamel coating as claimed in claim 4, further comprising a step of removing enamel glaze adhering to the transfer roller by contacting an end of the coating solution removing plate with a rotating surface of the transfer roller. Method.   6. The enamel coating method according to claim 5, wherein the coating liquid removing plate is provided perpendicular to a rotation surface of the transfer roller.   6. The transfer roller according to claim 5, wherein the transfer roller is a bar having a circular cross section, and has a tapered main body with a small diameter at a central portion and a diameter gradually increasing toward both ends. Enamel coating method.   The transfer roller is provided on an axis that forms an angle of 5 ° to 35 ° in a clockwise direction or a counterclockwise direction with respect to a transverse line perpendicular to the longitudinal direction of the baking chamber conveyor. The enamel coating method according to claim 7. Pretreatment chamber for pretreatment of the surface by feeding a metal tube, which is a fin tube for a heat exchanger with an electric heating pin formed on the surface, and feeding the metal tube after the pretreatment to the coating chamber inside the coating chamber A coating chamber that coats the surface of the metal tube with a enamel glaze supplied from an enamel nozzle supplied to the enamel and a firing chamber that feeds and fires the coated metal tube to the firing chamber Because
A coating brush for removing excess enamel glaze and bubbles from the surface of the metal tube on the front surface of the enamel glaze supply nozzle on the basis of the traveling direction of the metal tube is further provided,
An end coating part for coating the end of the electric heating pin once again with the enamel glaze before the metal tube enters the firing chamber,
Enamel coating equipment.   [10] The enamel coating apparatus according to claim 9, wherein the end coating part is an end brush coated with enamel glaze.   The stirrer for stirring the enamel glaze is further provided in a glaze storage container connected to the enamel spray nozzle and supplying the enamel glaze to the metal tube. Enamel coating equipment.   The conveyor for transferring the metal tube includes two or more transfer rollers, and the transfer roller rotates while supporting a lower portion of the metal tube to rotate and advance the metal tube along the conveyor. The enamel coating apparatus according to claim 9, characterized in that   One or more coating liquid removal plates are provided on the side or lower portion of the transfer roller located between the coating chamber and the baking chamber, respectively, and are inclined with respect to the rotation surface of the transfer roller, and the transfer roller rotates. 13. The enamel coating apparatus according to claim 12, wherein an end of the coating liquid removing plate comes into contact with a rotation surface of the transfer roller and the enamel adhering to the transfer roller is removed.   The enamel coating apparatus according to claim 13, wherein the coating liquid removing plate is provided perpendicularly to a rotation surface of the transfer roller.   The enamel coating apparatus according to claim 13, wherein the coating liquid removing plate is made of a metal having high heat resistance.   The transfer roller according to claim 13, wherein the transfer roller is a bar having a circular cross section, and has a tapered main body with a small diameter at a central portion and a gradually increasing diameter toward both ends. Enamel coating equipment.   The transfer roller is provided on an axis that forms an angle of 5 ° to 35 ° in a clockwise direction or a counterclockwise direction with respect to a transverse line perpendicular to the longitudinal direction of the firing chamber conveyor, 17. The enamel coating apparatus according to claim 16, wherein the enamel is rotated and advanced by the rotation of the transfer roller and is transferred to the outfeed conveyor.

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