JP2017119257A - Coating booth for water paint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating booth for water paint where the required amount of an air stream can be supplied to a coating chamber while preventing a foreign matter removal filter from function deterioration and then the coating film quality of the water paint can be improved.SOLUTION: In a coating booth 1, the operation states of a heating burner 12 and a steam humidifier 14 are controlled by a control unit 30. Concretely, temperature control and humidity control are executed by properly adjusting the valve opening of a fuel control valve 31, an air flow control valve 32 and a steam control valve 17 so that detection temperature and detection humidity due to a temperature sensor 33 and a humidity sensor 34 coincide with set temperature and set humidity set at a temperature and humidity setter 35. Especially, the set temperature is preferably 15-35°C and the set humidity is preferably 20-70% (more preferably 30-60%) when coating with water paint.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a coating booth for water-based paints that provides a coating environment suitable for painting with water-based paints.

  In recent years, with the use of organic solvents, the amount of solvent paint used has decreased, while the use of water-based paints has become widespread in many industrial fields. is there. In particular, large-scale automobile production painting lines that have financial resources and can introduce large-scale air conditioning equipment can be used for painting with water-based paint by controlling the temperature and humidity of the painting environment using such air conditioning equipment. In recent years, various proposals have been made regarding painting techniques using water-based paints for such automobile production paint lines.

  Here, in addition to painting performed at the time of automobile production (hereinafter referred to as “production coating”) in the automobile production painting line, automobile painting is performed afterwards (hereinafter referred to as “repair painting”) such as during automobile repair. "). Automobile repair painting is frequently performed daily at many automobile repair shops throughout the country, and even in the field of repair painting, painting technology using water-based paints is an important technology that is expected to have great demand in the future. .

  However, the main body of repair painting for automobiles is often less funding than large companies that are the main body of production painting using automobile production painting lines. A large-scale painting facility such as a line cannot be introduced, and repair painting is generally performed using a small-sized automobile painting booth that can accommodate one automobile.

  In this automobile painting booth, an airflow is passed through the painting chamber for ventilation during painting. For example, the flow velocity (wind velocity) of this airflow is 0 at a predetermined position in the painting chamber and there is no object to be painted. Control is performed so as to be around 2 m / s. Since this air flow is supplied from outside the painting booth, it contains a lot of foreign matter such as dust and other floating substances. When such foreign matter flows into the painting chamber, the foreign matter adheres to the paint film surface of the automobile and so on. There is a risk that the quality of the coating film will deteriorate. For this reason, in the painting booth, in order to remove foreign substances from the airflow flowing into the painting chamber, a dust collection filter is installed in the airflow passage.

JP 2012-543 A

  However, many of the above-described automobile paint booths are generally suitable for the use of solvent paints. Specifically, since solvent paint is finished by drying the coating film and volatilizing the solvent, the paint booth that uses solvent paint passes through the paint room to adjust the temperature of the paint room. However, it has a problem that it is difficult to perform repair painting using a water-based paint because it does not have a function of adjusting the humidity in the painting chamber.

  Thus, when performing repair painting using water-based paint in the painting booth, it is necessary to adjust the humidity of the painting room, for example, spray water droplets on the airflow before supplying to the painting room, and after this water droplet spraying There has been proposed a humidification method in which the airflow is heated to humidify the airflow and supply it to the coating chamber (see Patent Document 1).

  However, in the painting booth using this humidification method, it is possible to humidify the water in the gas-liquid mixed state in the airflow, but liquid water is mixed in the airflow supplied to the painting chamber, so this moisture is applied to the painting booth. It is trapped by the dust collecting filter before it flows into the chamber, the dust collecting filter gets wet and becomes clogged, and its function deteriorates, for example, it is difficult to pass a sufficient air flow through the coating chamber. there were.

  The present invention has been made in order to solve the above-described problems, and can prevent the deterioration of the function of the foreign matter removal filter while supplying a necessary amount of airflow to the coating chamber. It aims to provide a paint booth for water-based paints that can be improved.

  To achieve this object, the paint booth for water-based paint according to the first aspect of the present invention includes an airflow generating means for generating an airflow, and a ventilation passage through which the airflow generated by the airflow generating means passes from the upstream side toward the downstream side. And a coating chamber that forms a part of the air passage and in which a water-based paint is applied in a state in which an airflow passes through the air passage, and is disposed on the upstream side of the air passage from the coating chamber. A steam release means for releasing superheated steam into the airflow in the air passage and humidifying the airflow; a steam supply means for supplying superheated steam to the steam release means; and the steam release means from the steam supply means Gas-liquid separation means for separating the water contained in the superheated steam from the superheated steam.

  The foreign matter removal filter is disposed on the upstream side of the coating chamber in the air passage and on the downstream side of the vapor discharge means, and removes floating foreign matters from the air flow when the air current passes therethrough. is there.

  According to the coating booth for water-based paint of the first invention, the airflow is generated by the airflow generation means and passes through the air passage from the upstream side toward the downstream side. A coating chamber is provided in a part of the air passage, and in this coating chamber, a coating process using a water-based paint is performed in a state where an airflow passes therethrough. On the other hand, superheated steam supplied from the steam supply means moves from the steam supply means to the vapor discharge means via the gas-liquid separation means. During this movement, water (water droplets or other non-vaporized water particles) is transferred by the gas-liquid separation means. The same shall apply hereinafter) is separated and released into the airflow in the air passage by the vapor discharge means, and the airflow is humidified. The humidified airflow passes through the foreign matter removal filter to remove floating foreign matters and then flows into the painting chamber, contributing to an increase in humidity in the painting chamber.

  The paint booth for water-based paint of the second invention is the paint booth for water-based paint of the first invention, and is disposed on the upstream side of the vapor discharge means in the air passage and heats the airflow passing through the air passage A heating means is provided.

  According to the paint booth for water-based paint of the second invention, the air-flow passing through the air passage is heated by the air-flow heating means in addition to acting in the same manner as the water-borne paint booth of the first invention. While the heated air flow increases in temperature due to heating, the humidity also decreases due to drying accompanying the increase in the amount of saturated water vapor due to such heating, but it is caused by superheated steam released by the steam discharge means disposed downstream thereof. Humidified. The airflow thus heated and humidified passes through the foreign matter removal filter, and after the floating foreign matter is removed, flows into the painting chamber and contributes to an increase in temperature and humidity in the painting chamber.

  A paint booth for water-based paint according to a third aspect of the present invention is the paint booth for water-based paint according to the first or second aspect, wherein the paint booth forms part of the air passage and is provided between the vapor discharge means and the paint chamber, The ceiling back, which is the space into which the air flow humidified by the vapor discharge means flows, the coating chamber which is a space formed below the ceiling, and the entire ceiling surface of the coating chamber, A ceiling material that divides the painting chamber and the ceiling from above and below, and the airflow passes through the foreign material removal filter that removes floating foreign materials from the airflow. And an underfloor exhaust section that allows the downdraft flowing into the chamber to flow out of the coating chamber.

  According to the paint booth for water-based paint of the third aspect of the invention, the air flow in which superheated steam is added by the steam discharge means flows in the air passage while acting in the same manner as the paint booth for water-based paint of the first or second invention. On the way, it flows into the back of the ceiling, passes through the foreign material removal filter as the ceiling material from this back of the ceiling, and flows into the painting chamber as a downdraft. Since the foreign material removal filter, which is a ceiling material, is entirely covered on the ceiling surface of the painting chamber, the airflow flows entirely from the ceiling material into the painting chamber to humidify or heat the painting chamber as a whole. . The airflow passes through the foreign matter removal filter to remove floating foreign matters such as airborne matter, and after passing through the painting chamber, it flows out to the underfloor exhaust section and is exhausted.

  The paint booth for water-based paint according to a fourth aspect of the present invention is the paint booth for water-based paint according to the third aspect of the invention, wherein the air flow generating means is an air supply / air blowing means for sending an air current to the back of the ceiling; And an exhaust air blowing means for discharging the airflow.

  According to the paint booth for water-based paint of the fourth aspect of the invention, while acting in the same manner as the paint booth for water-based paint of the third aspect of the invention, The exhaust air is discharged from the painting chamber through the under floor exhaust section by the exhaust air blowing means.

  The water-based paint booth according to a fifth aspect of the present invention is the water-based paint booth according to any of the first to fourth aspects of the invention, wherein the gas-liquid separation means is interposed between the steam supply means and the steam discharge means. And a porous body having a large number of fine voids communicating from the vapor supply means to the vapor discharge means, wherein the voids of the porous body transfer superheated steam from the vapor supply means to the vapor. This is a passage to be moved to the discharge means, and the water contained in the superheated steam comes into contact with the skeleton of the porous body, so that the water is captured and separated from the superheated steam.

  According to the paint booth for water-based paint of the fifth aspect of the invention, the gas-liquid separation means operates from the steam supply means to the steam discharge means, in addition to acting in the same manner as any of the water paint paint booths of the first to fourth inventions. The moving superheated water vapor passage is formed by the fine voids of the porous body, and the water contained in the superheated water vapor collides with the skeleton of the porous body in the process of passing the superheated water vapor through the voids of the porous body. By this collision, moisture is attached to the porous body and captured. For this reason, the superheated steam is discharged into the airflow in the air passage by the steam discharge means in a state where excess water is removed.

  The paint booth for water-based paint according to a sixth aspect of the invention is the paint booth for water-based paint according to any of the third to fifth inventions, wherein the foreign matter removal filter has a large number of fine voids communicating with each other in the airflow passage direction. In order to capture floating foreign substances contained in the airflow by passing the airflow through the voids of the porous body, the skeleton of the porous body is given adhesiveness .

  According to the water-based paint booth of the sixth aspect of the invention, the foreign matter removal filter operates in the same manner as any one of the water-based paint booths of the third to fifth aspects of the invention, and the foreign matter removing filter In the process of forming a microscopic void in the porous body, and the airflow passes through the void in the porous body, causing the floating foreign matter included in the airflow to collide with the skeleton of the porous body, Adsorbs and captures suspended foreign matter due to its adhesiveness. For this reason, the airflow flows from the back of the ceiling into the painting room in a state where excess floating foreign matters are removed.

  According to the coating booth for water-based paints of the first invention, for example, even if the paint chamber is dried due to a decrease in humidity due to the climate and the paint chamber is unsuitable for painting a water-based paint due to such drying, The supplied air stream is humidified with superheated steam, and the humidified air stream is supplied to and passed through the coating chamber, so that the humidity in the coating chamber can be increased, and the aqueous paint forming the coating forms a coating film. It is possible to create a wet state suitable for the interior of the paint chamber and to improve the quality of the water-based paint film.

  Further, the humidification of the airflow is performed by releasing the superheated steam having a temperature higher than that of the saturated water vapor into the air current by the steam releasing means, and therefore, it is included in the air current as compared with the case of humidification by the spraying of the saturated water vapor. The coating chamber is difficult to condense and liquefy due to the condensation of water vapor, prevents the water vapor from lowering in temperature by the time the humidified airflow passes through the coating chamber, and clogs the contaminant removal filter due to condensation of saturated water vapor. This has the effect of preventing a decrease in the amount of airflow supplied to the.

  Furthermore, since the superheated steam released into the air stream by the steam release means is removed by the gas-liquid separation means before the release, the moisture that causes clogging due to the wetting of the foreign matter removal filter is released into the air stream. Thus, there is an effect that it is possible to further prevent a decrease in the amount of airflow supplied to the painting chamber due to clogging of the foreign matter removal filter.

  According to the paint booth for water-based paints of the second invention, in addition to the effects exhibited by the paint booth for water-based paints of the first invention, the air flow heating means is disposed upstream of the air blowing passage from the paint chamber. When the temperature in the painting room is low and unsuitable for painting with water-based paint, the air current supplied to the painting room is heated and passed through the painting room, so that the temperature in the painting room can be applied to water-based paint. The temperature can be raised to a suitable temperature range, and the coating film quality of the water-based paint can be improved.

  However, heating of the airflow by the airflow heating means also causes a decrease in the humidity of the airflow due to an increase in the amount of saturated water vapor accompanying an increase in the temperature of the airflow, but on the downstream side of the airflow heating means in the blowing passage and upstream of the coating chamber. Since the steam release means is disposed, the steam release means releases superheated steam to the air passage, humidifies the airflow supplied to the coating chamber and passes it through the coating chamber, thereby reducing the humidity of the coating chamber to water. It is possible to increase the humidity range suitable for the coating of the paint and to improve the coating film quality of the aqueous paint.

  Further, since the airflow heating means heats the airflow in the air passage on the upstream side of the vapor discharge means, superheated water vapor can be discharged and humidified in the heated airflow, so that the arrangement state is opposite to this. In other words, as in the case where the steam discharge means is located upstream of the airflow heating means, the airflow in the airflow passage is humidified and then heated and dried to reduce the humidity of the airflow supplied to the coating chamber. In addition, there is an effect that it is possible to prevent deterioration of the coating quality of the water-based paint due to airflow heating by the airflow heating means.

  In addition, since the air flow can be heated by the air flow heating means, there is also an effect that the moisture trapped in the foreign matter removal filter can be re-evaporated and removed by the heated air flow.

  According to the paint booth for water-based paints of the third invention, in addition to the effects exhibited by the paint booth for water-based paints of the first or second invention, when the humidified airflow flows into the back of the ceiling of the paint room, the ceiling of the paint room Since it passes through the foreign matter removal filter, which is a ceiling material that covers the entire surface, and flows down into the painting chamber from this entire ceiling surface, the humidity of the entire painting chamber can be adjusted more evenly, and the water-based paint can be applied. There is an effect that the film quality can be further improved. Moreover, since the floating foreign matter can be removed by the foreign matter removing filter immediately before the humidified airflow flows into the coating chamber, a cleaner airflow can be supplied into the coating chamber, and the coating film quality of the aqueous paint can be further improved.

  According to the paint booth for water-based paints of the fourth invention, in addition to the effects exhibited by the paint booth for water-based paints of the third invention, the air flow blown to the back of the ceiling by the supply air blowing means flows from the back of the ceiling into the paint room. In this case, the foreign matter removal filter becomes a resistance, but by exhausting the air in the painting chamber from the exhaust under the floor by the exhaust air blowing means, the humidified air current can be moved to the painting chamber more smoothly without staying behind the ceiling. There is an effect that it can be humidified by inflow.

  According to the paint booth for water-based paints of the fifth invention, in addition to the effects exhibited by the paint booth for water-based paints of any one of the first to fourth inventions, Condensed water can be prevented from entering the airflow, so that the condensed water can be prevented from adhering to the foreign matter removal filter, and the foreign matter removal filter from getting wet and clogging. There is an effect that it is possible to avoid a situation in which the supply amount of the humidified airflow to the chamber is lowered and the quality of the coating film of the water-based paint is lowered.

  According to the paint booth for water-based paints of the sixth invention, in addition to the effects exhibited by the paint booth for water-based paints of any of the third to fifth inventions, the foreign matter removing filter has a porous skeleton part that is adhesive. Therefore, there is an effect that it is possible to improve the coating quality of the water-based paint by increasing the removal rate of floating foreign matters by the adhesiveness and allowing a cleaner airflow to flow into the coating chamber.

  On the other hand, when the amount of trapped foreign matter increases due to adhesiveness, the porosity of the foreign matter removal filter decreases, so clogging due to the wetness of the foreign matter removal filter is likely to occur. Since superheated steam that is hard to condense at high temperature compared with saturated steam is added for humidification, there is an effect that clogging due to wetting of the foreign matter removal filter can be suppressed.

  In particular, since superheated steam from which condensed water has been removed is added to the airflow by the vapor discharge means, there is an effect that wetting of the foreign matter removal filter due to the passage of the airflow can be further reduced.

BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of the coating booth for motor vehicles which is one Example of the coating booth for water-based paints of this invention, Comprising: The piping diagram of a humidification system including a steam humidifier, a steam boiler, etc., and the airflow which passes through the inside It is also the conceptual diagram which showed. It is a longitudinal cross-sectional view of a steam humidification chamber, Comprising: It is a longitudinal cross-sectional view in the II-II line of FIG. It is a top view of a steam humidifier. It is sectional drawing which showed the internal structure of the steam humidifier, and is a partial longitudinal cross-sectional view in the IV-IV line of FIG. It is a longitudinal cross-sectional view in the VV line of FIG. It is the block diagram which showed an example of the whole structure of the coating booth of a present Example. It is the block diagram which showed an example of the electrical constitution of the painting booth of a present Example.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. FIG. 1 is an external view of a paint booth 1 for an automobile, which is an embodiment of a water paint paint booth according to the present invention, and includes a humidifying system including a steam humidifier 14 and a steam boiler 16 (see FIG. 6). ) And a conceptual diagram showing an air flow F (arrow shown in FIG. 1) passing through the piping diagram.

  As shown in FIG. 1, a painting booth 1 for an automobile includes a booth body 2 in which a roof portion and a peripheral wall portion are surrounded by a panel material P in which a heat insulating material is laminated. The booth main body 2 includes a booth ceiling back 3 which is a space provided in the upper part thereof, and a painting chamber 4 which is a space provided below the booth ceiling back 3 and accommodates an automobile to be painted. The painting booth 1 includes a blower facility that generates an airflow F that is passed through the painting chamber 4 of the booth body 2.

  This blower equipment mainly includes an air supply duct 5 that supplies an airflow F to the painting chamber 4, an air supply fan 6 that is a blower disposed in the air supply duct 5, and an airflow F from the painting chamber 4. An exhaust pit 7 and an exhaust duct 8 to be discharged, and an exhaust fan 9 which is a blower disposed in the exhaust duct 8 are provided. The air supply fan 6 sucks air from the air supply port 5 a into the air supply duct 5 and blows the airflow F to the painting chamber 4. The exhaust fan 9 passes the air in the painting chamber 4 through the exhaust pit 7. By sucking into the exhaust duct 8, the airflow F is blown to the outside from the exhaust port 8a.

  The air flow F generated by the blower facility draws air from outside the painting booth 1 into the air supply duct 5 through the air supply port 5 a by the air blowing force of the air supply fan 6. Air is sent to booth ceiling 3. The booth ceiling 3 is provided above the painting chamber 4 in the painting booth 1. A frame (not shown) in a plan view lattice is disposed at the bottom of the booth ceiling 3, and a dust collection filter 10 is provided in all openings provided in a plurality of lattices in the frame. Is covered.

  The dust collection filter 10 is spread all over the bottom of the booth ceiling 3, and partitions the booth ceiling 3 and the painting chamber 4 so as to cover the entire ceiling surface of the painting chamber 4. The dust collection filter 10 is formed of a porous body having fine voids such as a thick non-woven fabric having adhesiveness for collecting dust. Can pass through, and an adhesive is attached to the skeleton of the porous body, and dust can be captured by the adhesive.

  The airflow F passing through the dust collection filter 10 flows into the painting chamber 4 from the entire booth ceiling 3, passes through the painting chamber 4, and flows into an exhaust pit 7 provided under the floor of the painting chamber 4. The exhaust pit 7 is a groove provided in the lower floor of the painting chamber 4, and a lattice-like pit lid 11 such as a grating is covered on the upper opening of the exhaust pit 7. In the grid-like pit lid 11, a plurality of gaps arranged in a grid form serve as inflow ports through which the airflow F flows into the exhaust pit 7. The airflow F flowing into the exhaust pit 7 is sucked from the exhaust pit 7 by the exhaust fan 9 and exhausted from the exhaust port 8a to the outside through the exhaust duct 8.

  Further, a heating burner 12 that is a heater for heating the airflow F is disposed immediately after the air supply fan 6 in the air supply duct 5, and passes through the air supply duct 5 by heating of the heating burner 12. The airflow F to be heated is heated. The air supply duct 5 extends right above the arrangement portion of the heating burner 12, and the side portion at the upper end thereof is connected to the side portion of the booth ceiling 3.

  However, the air supply duct 5 is not directly connected to the booth ceiling 3, and a steam humidification chamber 13 is provided between the upper end of the air supply duct 5 and the booth ceiling 3. The airflow F that has passed through the air supply duct 5 passes through the steam humidification chamber 13 and flows into the booth ceiling 3.

  In this way, the painting booth 1 is connected to the air supply duct 5, the steam humidification chamber 13, the booth ceiling 3 of the booth main body 2, the painting chamber 4, the exhaust pit 7, and the exhaust duct that lead from the air supply port 5 a to the exhaust port 8 a. Eight air passages 50 (see FIG. 6) are provided. The airflow F passing through the air passage 50 is generated by the air supply fan 6 built in the air supply duct 5 and the exhaust fan 9 built in the exhaust duct 8. For example, the flow velocity of the air flow F is about 0.2 m / s.

  Specifically, for example, the flow velocity of the air flow F is obtained by dividing the floor area (booth floor area) of the painting chamber into 16 or more sections, and setting a measurement point 1.5 m above the floor from the center of each section for all the sections. The average value of the flow velocity at all the measurement points (average flow velocity value) is 0.2 m / s or more, and the flow velocity at each measurement point is 0.5 to 1.5 times the average flow velocity value. The air supply fan 6 and the exhaust fan 9 are adjusted so as to be within the range.

  The painting booth 1 includes a dust collection air supply filter 5b and an exhaust filter 8b disposed in the air supply duct 5 and the exhaust duct 8, and flows into the steam humidification chamber 13 by the air supply filter 5b. The dust contained in the airflow F is reduced, and the dust contained in the airflow F exhausted outdoors by the exhaust filter 8b is reduced.

  The steam humidification chamber 13 is provided with a pair of upper and lower steam humidifiers 14 and 14. The steam humidifiers 14 and 14 are steam humidifiers that jet superheated steam into the steam humidification chamber 13 and humidify the airflow F toward the coating chamber 4. A steam pipe 15 is connected to each steam humidifier 14, and steam (mainly saturated steam) is supplied from the steam boiler 16 through the steam pipe 15. The steam pipe 15 is a steam transport pipe, and a steam control valve 17 for adjusting the flow rate of the high-pressure steam supplied to the steam humidifier 14 is provided in the middle of the steam pipe 15.

  The steam boiler 16 is a steam generator that generates high-pressure steam having a working pressure range of, for example, 0.39 to 0.59 MPa (maximum pressure 0.69 MPa), and vaporizes the soft water generated by the soft water device 18. The water softener 18 softens water supplied from a water source 19 such as a water supply and supplies the water to the steam boiler 16.

  The steam humidifier 14 is connected to a condensed water pipe 20 that discharges condensed water formed by cooling the superheated steam in the steam humidifier 14. The condensed water collected at the base end (the left side in FIGS. 2 to 4) in the steam humidifier 14 is discharged to the condensed water pipe 20 and discharged to the outside through the condensed water pipe 20.

  FIG. 2 is a longitudinal sectional view of the steam humidifying chamber 13 and is a longitudinal sectional view taken along line II-II in FIG. 1, and FIG. 3 is a plan view of the steam humidifier 14. As shown in FIG. 2, the steam humidification chamber 13 is a duct pipe formed in a rectangular shape in cross section using the panel material P described above, and a pair of upper and lower steam humidifiers 14 and 14 are disposed therein. ing. Each steam humidifier 14 is a rod-like body extending from the panel material P on one side of the steam humidifying chamber 13 in the lateral width direction (left side in FIG. 2) toward the lateral width direction (left and right direction in FIG. 2) in the steam humidifying chamber 13. They are arranged in a state spaced from each other in the vertical direction (vertical direction in FIG. 2).

  The steam humidifier 14 has a mounting plate 21 at its base end (left side in FIG. 2) for fixing itself to the panel material P on the side surface of the steam humidifying chamber 13. It is fastened and fixed to the panel material P of the steam humidification chamber 13 using screw fasteners (not shown) such as bolts and nuts.

  The steam humidifier 14 includes a hollow rod-like outer tube 22 that forms the outer peripheral portion thereof. One surface of the mounting plate 21 is abutted and fixed to the base end surface (left side in FIG. 2) of the outer tube 22, and the condensed water pipe connecting portion 23 and the steam pipe connecting portion 24 are connected to the other surface of the mounting plate 21. Is fixed on the spot. The condensed water piping connection part 23 is a connection joint which connects the condensed water piping 20 which is a condensed water transport pipe. The steam pipe connection part 24 is a connection joint that supplies superheated steam to an inner tube 25 to be described later when the steam pipe 15 is connected.

  As shown in FIG. 3, the steam humidifier 14 has a plurality of steam discharge ports 22 a formed at equal intervals in the axial direction of the outer tube 22 (left and right direction in FIG. 3) at the upper end surface of the outer peripheral portion of the outer tube 22. Has been. The plurality of steam discharge ports 22 a are perforations for discharging (spouting) superheated steam into the steam humidification chamber 13. That is, according to the steam humidifier 14, the steam (mainly saturated steam) supplied from the steam boiler 16 is depressurized from the steam pipe 15 through the steam pipe connection part 24 to be changed to superheated steam, and the inner tube 25. The superheated steam is ejected from the inner tube 25 into the outer tube 22, and the superheated steam is ejected upward from the plurality of steam discharge ports 22 a in the outer tube 22 into the steam humidification chamber 13. To do.

  Here, the steam humidifier 14 has a predetermined angle (for example, a gradient of 1 to 2% (= tan −1 (0.01) −) from the distal end (right side in FIG. 2) toward the proximal end (left side in FIG. 2). tan-1 (0.02))). By condensing the steam humidifier 14 in this way, the condensed water generated in the steam humidifier 14 flows in the steam humidifier 14 from the distal end side to the proximal end side, and the proximal end of the steam humidifier 14 It is collected in the condensate pipe connection part 23 in the part.

  A condensed water trap 26 is provided in the middle of the condensed water pipe 20 connected to the condensed water pipe connecting portion 23. The condensate trap 26 is suspended downward by a predetermined length from the connection portion with the condensate pipe connection portion 23, and the lower end of the downward suspension portion is bent in an arc shape and folded upward. This is a U-shaped tube whose tip is further hung upward by a predetermined length and whose upper end is bent in an arc shape and folded downward. The static pressure in the steam humidifying chamber 13 is a positive pressure.

  4 is a cross-sectional view showing the internal structure of the steam humidifier 14, and is a partial vertical cross-sectional view taken along the line IV-IV in FIG. FIG. 5 is a longitudinal sectional view taken along the line VV in FIG. As shown in FIGS. 4 and 5, the steam humidifier 14 includes the above-described condensed water pipe connecting portion 23, the mounting plate 21, the outer tube 22 having a plurality of steam discharge ports 22 a, and the steam pipe connecting portion. 24, and further includes an inner tube 25, a decompressor 27, a silencer 28, and a condensed water separating member 29.

  The plurality of vapor discharge ports 22 a communicate with the inner peripheral portion of the outer tube 22. A hollow rod-like inner cylindrical tube 25 is inserted in the inner peripheral portion of the outer cylindrical tube 22 in the same direction as the axial direction (left and right direction in FIG. 4). The outer cylindrical tube 22 and the inner cylindrical tube 25 are A double tube structure is formed. The steam pipe connection portion 24 is provided with a decompressor 27 through which high-pressure steam can pass in the middle of the steam flow path inside. The decompressor 27 is, for example, a throttle orifice, and decompresses the high-pressure steam that passes through the orifice, changes it to superheated steam, and supplies it to the inner tube 25. The muffler 28 reduces the sound generated by the water vapor that has passed through the decompressor 27 of the steam pipe connection 24 due to the decompression.

  The inner cylindrical tube 25 is inserted into the entire inner peripheral portion of the outer cylindrical tube 22 from one end in the axial direction (left side in FIG. 4) to the other end (right side in FIG. 4). In the inner tube 25, a plurality of steam ejection holes 25a are formed at equal intervals in the axial direction (the left-right direction in FIG. 4) of the inner tube 25 on the lower end of the outer periphery in the range from one end to the other end. Has been. The plurality of steam ejection holes 25 a are narrow groove-shaped perforations communicating with the inner peripheral portion of the inner tube 25. The inner tube 25 has a steam pipe connection 24 connected to a base end thereof via a pressure reducer 27 and a silencer 28. The high-pressure steam supplied from the steam boiler 16 through the steam pipe 15 is depressurized by the decompressor 27 by passing through the steam pipe connection portion 24 to become superheated steam, and is silenced by passing through the silencer 28 to be inner tube. 25.

  The condensed water separation member 29 is a gas-liquid separation member that collects and separates water particles (including water droplets) contained in superheated steam and removes the water particles as condensed water. The condensed water separating member 29 is wound around the entire outer periphery (see FIG. 5) of the inner tube 25 and the entire axial direction (see FIG. 4). The condensed water separation member 29 is a three-dimensional network structure (three-dimensional network structure), open-cell porous body, or other porous body having corrosion resistance and heat resistance against superheated steam and moisture.

  The three-dimensional network structure is formed of a thin wire material (for example, a diameter of about 0.1 to 0.3 mm) such as a metal material, a ceramic material, or a resin material. For example, those made of metal materials include those made of wire mesh such as stainless steel, and those made of ceramic materials include those made of alumina, cordierite, silica / alumina, zirconia or silicon carbide. There are resin materials made of PP resin, fluororesin (PFA or FEP, etc.) and other resin materials.

  Moreover, as an open-cell porous body, there exists a ceramic foam which has a foam structure of an open cell, for example. As another porous body, there is a metal punching metal, for example.

  According to the condensed water separating member 29, when the superheated steam passes through the voids inside the condensed water separating member 29, the thin wire material corresponds to the skeleton part (for example, a three-dimensional network structure made of a metal material). ) Collide with water particles contained in superheated steam (mainly inertial collisions, interception collisions, collisions based on Brownian diffusion), so that the water particles are captured by the wettability and capillary action of this skeleton. Many trapped water particles are aggregated by surface tension and dropped to the inner bottom portion 22b having a pointed shape (see FIG. 5) at the lower end of the outer periphery of the outer tube 22 through the gap.

  According to the steam humidifier 14, the high-pressure steam supplied from the steam boiler 16 through the steam pipe 15 is reduced in pressure via the decompressor 27 in the steam pipe connection portion 24 to be changed to superheated steam, and is shocked by the silencer 28. After the sound is silenced, it flows into the inner tube 25 and is ejected downward from the plurality of vapor ejection holes 25a toward the inside of the condensed water separation member 29. The superheated steam spouted into the condensed water separation member 29 moves upward along the inner peripheral portion of the outer cylindrical tube 22 while passing through the space inside the condensed water separating member 29, and a plurality of steams in the outer cylindrical tube 22. It is discharged into the steam humidification chamber 13 from the discharge port 22a.

  On the other hand, according to the steam humidifier 14, while the superheated steam passes through the void of the condensed water separation member 29, the water particles contained in the superheated steam collide with the skeleton of the porous body and are captured. The condensed water obtained by agglomerating a large number of the captured water particles is dropped to the inner bottom portion 22b of the outer cylindrical tube 22 to flow toward the base end portion of the outer cylindrical tube 22, and is collected in the condensed water pipe connecting portion 23. The water is drained to the condensed water pipe 20.

  FIG. 6 is a block diagram showing an example of the overall configuration of the painting booth 1 of this embodiment, and FIG. 7 is a block diagram showing an example of the electrical configuration of the painting booth 1 of this embodiment. As shown in FIG. 7, the painting booth 1 includes a control device 30 using a PLC (Programmable-Logic-Controller) or the like. The control device 30 includes a fuel control valve 31 and a blower control valve 32 for the heating burner 12, a steam control valve 17 for the steam humidifier 14, a temperature sensor 33, a humidity sensor 34, and a temperature / humidity setter 35. Are electrically connected to each other.

  As shown in FIG. 6, a fuel tank 37 is connected to the heating burner 12 via a fuel pipe 36, and a blower blower 39 is connected via a blower pipe 38. The fuel tank 37 is a fuel source that supplies fuel to the heating burner 12, and the blower blower 39 is a blower that blows air required for combustion to the heating burner 12. A fuel control valve 31 is provided in the fuel pipe 36, and a blow control valve 32 is provided in the blow pipe 38.

  As shown in FIG. 7, the fuel control valve 31 is a motor-driven flow control valve (flow control valve), and includes a control drive motor (control motor) 31 a connected to the control device 30. The fuel control valve 31 adjusts the forward / reverse rotation amount of the control drive motor 31 a based on a control signal from the control device 30, thereby adjusting the valve opening degree of the fuel supplied from the fuel tank 37. Control the flow rate.

  The blower control valve 32 is a motor-driven flow control valve (flow control valve), and includes a control drive motor (control motor) 32 a connected to the control device 30. This air blow control valve 32 adjusts the forward / reverse rotation amount of the control drive motor 32 a based on the control signal from the control device 30, thereby adjusting the valve opening degree of the air supplied from the blow blower 39. Control the flow rate.

  The fuel control valve 31 and the blower control valve 32 adjust the air-fuel ratio of the heating burner 12 based on a control signal from the control device 30, thereby controlling the amount of heat generated by the heating burner 12 and passing through the blower passage 50. The temperature of the airflow F is controlled. That is, the control device 30 matches the temperature of the coating chamber 4, that is, the temperature detected by the temperature sensor 33, with the set temperature by controlling the temperature of the air flow F passing through the air passage 50 by controlling the amount of heat generated by the heating burner 12. To control the temperature.

  The steam control valve 17 adjusts the flow rate of high-pressure steam supplied from the steam boiler 16 to adjust the discharge amount of superheated steam from the steam humidifier 14, and the humidity of the airflow F passing through the air passage 50. Used for control. The steam control valve 17 is a motor-driven flow control valve (flow control valve), and by adjusting the forward / reverse rotation amount of the control drive motor (control motor) 17a by a control signal from the control device 30, The flow rate of the high-pressure steam passing through the steam pipe 15 is controlled by adjusting the valve opening, and as a result, the discharge amount of the superheated steam is controlled.

  The temperature sensor 33 is a sensor that detects the temperature in the painting chamber 4, and the humidity sensor 34 is a sensor that detects the humidity in the painting chamber 4, both of which are installed in the painting chamber 4, Are output to the control device 30 at a predetermined detection timing. The temperature / humidity setting device 35 has an operation panel 35a that is operated by a person to set the temperature and humidity of the coating chamber 4, and the setting temperature and the setting humidity of the coating chamber 4 are set via the operation panel 35a. This is a device for inputting and setting the value to the control device 30.

  According to the control device 30 described above, the operating states of the heating burner 12 and the steam humidifier 14 are controlled. Specifically, the valve openings of the fuel control valve 31, the blower control valve 32, and the steam control valve 17 are controlled. By appropriately adjusting, the temperature control and the humidity control are executed so that the detected temperature and the detected humidity by the temperature sensor 33 and the humidity sensor 34 coincide with the set temperature and set humidity set in the temperature / humidity setter 35.

  Here, if an example of a set temperature and a set humidity by the temperature / humidity setting device 35 is given at the time of painting in the painting chamber 4 using a water-based paint and subsequent drying, the set temperature is set at the time of painting. While setting to 15-35 degreeC, it is preferable to set preset humidity to 20-70% (more preferably 30-60%). On the other hand, for drying after painting, the set temperature is set to 60 to 80 ° C., but humidification at the time of drying is unnecessary, so the set humidity is set to 0% or humidity control is performed. It is preferable to stop execution.

  The present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. It can be guessed.

  For example, in the present embodiment, the exhaust pit 7 is recessed as an underfloor exhaust portion in the lower floor portion below the floor material of the booth main body 2, but the embodiment of the underfloor exhaust portion is not necessarily limited to this. An exhaust pit may be built in the floor material itself of the main body 2. In the present embodiment, the heating burner 12 is described as an example of the airflow heating means. However, the embodiment of the airflow heating means is not necessarily limited to this, and the airflow passing through the air passage 50 is heated. As long as the heat source can raise the temperature, an electric heater or other heater may be used.

  In the present embodiment, the dust collection filter 10 having adhesiveness is described as the foreign matter removal filter. However, the foreign matter removal filter (including the dust collection filter; the same applies hereinafter) is not necessarily limited thereto. Instead, a non-adhesive foreign matter removal filter may be used. In the present embodiment, the steam humidification chamber 13 is disposed on the downstream side of the arrangement position of the heating burner 12 in the air passage 50, but this positional relationship is not necessarily limited to this, and temperature control and Although the humidity control becomes difficult and the effect may be reduced, for example, the steam humidification chamber 13 may be arranged upstream of the arrangement position of the heating burner 12 in the air blowing path 50.

1. Painting booth (painting booth for water-based paint)
2 Booth body 3 Booth ceiling (ceiling)
4 Painting room 6 Air supply fan (a part of air supply and air generation means and airflow generation means)
7 Exhaust pit (under-floor exhaust section)
9 Exhaust fan (exhaust ventilation means, part of airflow generation means)
10 Dust collection filter (ceiling material, foreign matter removal filter)
12 Heating burner (airflow heating means)
16 Steam boiler (part of steam supply means)
22a Vapor discharge hole (part of vapor discharge means)
25a Steam outlet (part of steam supply means)
29 Condensate separation member (gas-liquid separation means)
50 Air passage (air passage)
F Airflow

Claims (6)

An airflow generating means for generating an airflow, an airflow passage through which the airflow generated by the airflow generating means passes from the upstream side toward the downstream side, and part of the airflow passage, and the airflow passes through the airflow passage. In the paint booth for water-based paints, which is equipped with a paint room where water-based paints are processed in the state,
Vapor discharge means disposed on the upstream side of the blowing passage from the coating chamber, and releasing superheated steam into the airflow in the blowing passage to humidify the airflow;
Steam supply means for supplying superheated steam to the steam discharge means;
Gas-liquid separation means for separating water contained in superheated steam from the superheated steam disposed in a passage through which superheated steam moves from the steam supply means to the steam discharge means. painting booth.   2. The coating booth for water-based paint according to claim 1, further comprising airflow heating means disposed on the upstream side of the vapor discharge means in the air passage and heating an airflow passing through the air passage. The back of the ceiling, which is a space that forms part of the air passage and is provided between the vapor discharge unit and the coating chamber and into which the airflow humidified by the vapor discharge unit flows,
The painting room which is a space formed below the ceiling; and
A foreign material removal filter that is entirely covered on the ceiling surface of the painting chamber, is a ceiling material that divides the painting chamber and the back of the ceiling up and down, and removes floating foreign substances from the air current by passing the air current;
The water-based paint according to claim 1 or 2, further comprising an underfloor exhaust unit that causes the descending airflow that has passed through the foreign matter removal filter, which is the ceiling material, and flowed into the coating chamber to flow out of the coating chamber. Painting booth.   The said airflow production | generation means is equipped with the air supply ventilation means which sends an airflow to the said ceiling back, and the exhaust ventilation means which discharges | emits an airflow from the said painting chamber through the said underfloor exhaust part of Claim 3 characterized by the above-mentioned. Paint booth for water-based paint.   The gas-liquid separation means is a porous body that is interposed between the vapor supply means and the vapor discharge means and has a number of fine voids communicating from the vapor supply means to the vapor discharge means The void of the porous body is a passage for moving superheated steam from the vapor supply means to the vapor discharge means, and the water contained in the superheated steam contacts the skeleton of the porous body. The water-based paint booth according to any one of claims 1 to 4, wherein the water is captured and separated from superheated steam.   The foreign matter removal filter is a porous body having a large number of minute voids communicating in the airflow passage direction, and is included in the airflow when the airflow passes through the voids of the porous body. 6. The water-based paint booth according to claim 3, wherein the porous material has a skeleton portion for capturing floating foreign substances.

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