JPH08168702A - Waste coating material treating device for coating booth - Google Patents

Abstract

PURPOSE: To make it possible to prevent the unequal supply of a washing liquid and the unequal inflow of the washing liquid into a discharge flow passage for washing by allowing the washing liquid to flow over the ditch walls of the discharge flow passage side for washing in the ditch part for a washing liquid reservoir of a washing liquid downflow plate and the washing liquid to flow out to the discharge flow passage for washing. CONSTITUTION: A material 4 to be coated is subjected to electrostatic spray coating by a coating machine 7 while this material 4 is transported in a hanging state by means of a conveyor 6 of a hanger type within the coating booth 5. This waste coating material treating device 12 captures the coating material mists contained in the discharge air A from the internal area of the booth in the washing liquid W, thereby removing the coating material mists from the discharge air A. The washing liquid W is made to flow out to the discharge flow passage 12 for washing by overflow from the ditch wall 12 on the discharge flow passage 12C side for washing according to the inflow of the washing liquid from the upstream side in the ditch part 12D for the washing liquid reservoir formed at the downstream end of the washing liquid downflow plate 12A. As a result, the washing liquid W is made to flow uniformly in the transverse direction of the washing liquid downflow plate 12A.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray electrostatic coating method for electrostatically attracting a spray paint from a spray gun to apply it to an object to be coated. 2. Description of the Related Art Conventionally, in the above-mentioned spray electrostatic coating method, a high positive or negative voltage is applied to an electrode provided at a spray gun ejection port by a high voltage generator. Thus, the spray paint is charged during spraying from the spray gun, and the charged spray paint is attracted and applied to the electrically grounded object to be coated. However, in the above-mentioned conventional method, the handling paint has a conductivity (for example, metallic paint mixed with metal powder, attention has recently been paid to pollution prevention). Water-based paint that uses water as the main solvent), the paint supplied to the spray gun is continuous over the entire length of the supply path. Since there is a risk of electrical leakage from the voltage-applied electrodes to the paint tank side, which is the paint supply source, not only the paint tank and spray gun but also the paint supply system from the paint tank to the spray gun must be insulated from ground. However, there is a problem that the insulation equipment becomes large-scale. In particular, in spray painting, more than a dozen paint tanks of different color types are often connected to one spray gun through a paint color selection valve. The above problems were particularly pronounced because the entire system had to be insulated.
Therefore, in order to cope with such a problem, by supplying the paint supplied from the paint tank to the relay tank by dripping, and then supplying the paint from the relay tank to the spray gun, It is also conceivable that the leakage of electricity via the connection is cut off at the dripping portion, so that the necessary insulating portion can be reduced to only the portion after the relay tank. However, even so, since a relay tank must be added as one of the insulation facilities,
Also, when connecting multiple paint tanks to the spray gun, a large number of relay tanks are also required (that is, when changing the paint color, clean the paint supply passage after the paint color selection valve and the spray gun in the shortest possible time. In order to improve the coating efficiency, it is necessary to install the paint color selection valve as close to the spray gun as possible, so a relay tank will be provided for each paint color upstream of the paint color selection valve.) However, there was still an inadequate aspect in reducing the insulation equipment. The object of the present invention is to renew the form of the electric field itself for electrostatically attracting the spray paint to the object side,
The point is that the insulation equipment can be greatly reduced. The characteristic means of the spray electrostatic coating method according to the present invention is to form an electric field for attracting spray paint between a spray gun and an object to be coated. The system that sprays the paint from the spray gun is the ground side,
In addition, a positive voltage or a negative voltage is applied to the object to be coated in a state where the object to be coated is supported in an electrically insulating state, and the action and effect thereof are as follows. [Operation] That is, the paint (particles) sprayed from the spray gun is charged by the electric field formed between the spray gun on the ground side and the object to be applied with the voltage, and the charging causes the voltage to be applied. It is attracted to the object to be coated and efficiently adheres to the object. That is, according to the method of the present invention, since the electric field for attracting the paint is formed with the system on the side where the paint is sprayed from the spray gun as the ground side, a positive electrode for forming the electric field is formed. Or, there is no possibility that a negative high voltage current will leak to the paint supply source side via the conductive paint, and therefore the insulation equipment in the paint supply system becomes unnecessary and the object to be coated is simply electrically It is only necessary to provide simple insulation equipment to support the equipment in an insulated state, and as a result, the required insulation equipment can be greatly reduced compared to the case of using the conventional method. The total equipment cost can be drastically reduced. Embodiments of the present invention will now be described with reference to the drawings. An article to be coated (in this example, an automobile body) 4 that has been conveyed through the previous step 3 by a floor conveyor 2 while being placed on a trolley 1 is delivered to a hanger type conveyor 6 at the entrance of a coating booth 5, Then, while being conveyed in the coating booth 5 in a suspended state by the hanger type conveyor 6, a plurality of coating machines 7 installed in the coating booth 5 perform spray electrostatic coating, and then coating. Booth 5
At the outlet, it is placed on the carriage 1'from the hanger type conveyor 6 again and conveyed to the post-process 8 by the floor conveyor 2 '. In the coating booth 5, ventilation air is blown downward from the ceiling outlet 9 and obliquely downward from the side wall outlet 10 so that the air in the booth passes through the lattice floor 11 together with the excess sprayed paint mist. And is discharged to the waste paint treatment device 12 side under the booth. Booth 5
A large number of paint tanks 13 for storing paints of different color types are installed outside the paint tank, and the spray guns 14 of the respective coating machines 7 are provided with paint supply pipes 15 extending from the paint tanks 13, respectively. It is connected via a valve 16 for changing the paint color, and is also connected to a supply line 17 for compressed air for paint spraying. Each conveyor 2, 6, 2'and each coating machine 7
The central control unit controls the operation control, the switching operation of the coating color changing valve 16 and the like, and the article 4 to be coated is sequentially and electrostatically sprayed automatically by the central control unit. In order to make the coated object 4 suspended and supported by the hanger type conveyor 6 in an electrically insulated state when performing the spray electrostatic coating, the hanging rods 18 for suspending each coated object 4 on the conveyor 6 are respectively provided. Is provided with an insulator 19, and
A clamp device 20 is provided on the floor of the booth for automatically connecting and operating the article to be coated 4 that has reached the coating position corresponding to each coating machine 7 by a command from the central controller.
Therefore, by connecting the clamp device 20, a high positive voltage is applied from the high voltage generator 21 to the object 4 to be coated in the insulating and supported state. On the other hand, an electrode 14a for forming an electric field for attracting the spray paint is provided between the spray gun 14 and the object 4 to which a high voltage is applied, at the spray port of the spray gun 14 of each coater 7. The electrode 14a is electrically grounded. That is, a high voltage is applied to the coating object 4 with the spray gun 14 side being the ground side and the coating object 4 being supported in an electrically insulated state, whereby the paint sprayed from the spray gun 14 is applied. Particles are charged in a forming electric field between the spray gun 14 and the article to be coated 4, and the electrification causes the spray paint to be attracted to the side of the article to be coated 4 which is in a high voltage applied state. Try to apply it efficiently. Incidentally, when a predetermined spray electrostatic coating is applied, the connection of the clamp device 20 is automatically released in response to a command from the central control unit, and the transfer of the object to be coated is restarted. [Other Embodiments] (a) In the above-described embodiment, the positive high voltage is applied to the object to be coated in the insulating support state, but in some cases, the negative high voltage may be applied. good. (B) As a spray gun, various conventionally well-known electrostatic coating guns are used, and instead of electrically grounding the electrodes, a simple spray coating gun without electrodes is used. Then, it is sufficient to electrically ground any part of the paint supply system from the gun to the paint tank. (C) Spraying electrostatic coating may be performed while the object to be coated is stationary or while it is moving. In either case, the object to be coated is supported in an electrically insulated state. Various modifications can be made to the specific supporting means for achieving this. (D) Various improvements can be made to the means for applying a positive or negative voltage to the object to be coated in the state of being insulated and supported. For example, when spraying electrostatic coating while moving the object to be coated. In this case, the cord of the voltage applying clamp that is connected to the object to be coated has flexibility to allow movement of the object to be coated, or a sliding contactor that slides on the electric rail as the object to be coated is coated. It may be attached to the object side. (E) The spray gun on the ground side may be of a type that is sprayed by humans, instead of the type equipped with a coating robot or automatic coating machine. The structure of the booth to be formed and the type and structure of the conveyer for conveying the object to be coated may be arbitrary. (F) The present invention is particularly useful when using a paint having conductivity such as a water-soluble paint using water as a main solvent or a metallic paint mixed with metal powder, but the paint to be handled is The non-conductive paint or the powder paint may be used. (G) The target article to be coated may be any body such as a casing of an automobile body or a home electric appliance, or a steel material for various purposes. It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings] FIG. 1 Enlarged cross-sectional view [Fig. 2] Enlarged vertical sectional view [Explanation of symbols] 4 coated objects 14 spray guns

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[Procedure Amendment] [Date of submission] September 13, 1995 [Procedure Amendment 1] [Amendment target document name] Specification [Amendment target item name] Full text [Amendment method] Change [Amendment content] [Document name] Specification Book [Title of Invention] Waste paint treatment device for coating booth [Claims] A cleaning liquid is applied to the bottom of the inner area of the booth (5) for spray painting.
(W) Flowing plate (12A) for washing liquid in a tilted posture
Is provided on the downstream end side of the cleaning liquid flow-down plate (12A) and the air (A) discharged from the booth (5) together with the excess paint mist and the cleaning liquid flow-down plate (12A) .
Exhaust gas for cleaning that allows the cleaning solution (W) to flow down
A waste paint treatment device for a coating booth having a flow path (12C) , wherein the cleaning liquid flow-down plate (12A) has a groove portion (12D) for storing a cleaning liquid at a downstream end in its cross-sectional shape,
The cleaning exhaust flow path (12 ) in the groove (12D)
Overflow the groove wall (12E) on the side of C)
Washing the groove the cleaning exhaust passage from (12D) (12C)
A waste paint treatment device in a paint booth, which is formed to flow out the purified liquid (W) . Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a cleaning liquid flow-down plate having an inclined posture for flowing a cleaning liquid at the bottom of the booth interior where spray coating is performed. On the downstream end,
The present invention relates to a waste paint treatment apparatus for a paint booth, which has a cleaning exhaust passage through which the air discharged together with the surplus paint mist from the booth interior and the downwash liquid from the downwash plate are passed together. [0002] A waste paint treatment apparatus for a paint booth as described above causes a wash liquid to trap paint mist contained in the air discharged from the booth in the course of joining and passing through the wash exhaust passage. However, in the conventional waste paint treatment apparatus of this type, as shown in, for example, JP-A-60-31849, the downstream end portion of the cleaning liquid flow-down plate is not provided. The cleaning liquid flowing down from the upstream side does not stay and is formed on a simple plate edge that directly flows into the cleaning exhaust passage. However, in the above-mentioned conventional structure, since the entire cleaning liquid flows down from the upstream side to the downstream side end of the cleaning liquid flow-down plate as a film-like flow without staying, the cleaning liquid flows down. The paint mist that tends to adhere to the plate surface of the falling plate and the paint slag falling from the inside of the upper booth can be washed away with the falling cleaning liquid, which has the advantage of reducing cleaning maintenance on the cleaning liquid falling plate. When there is unevenness in the supply of the cleaning liquid in the width direction of the falling plate (the depth direction of the paper in Fig. 1) or when the cleaning liquid is uneven due to manufacturing errors, etc. Even if there is only a small amount, due to the unevenness and unevenness, unevenness in the width direction of the flow-down plate is caused by the flow of the cleaning liquid from the downstream edge of the wash-flow plate to the cleaning exhaust flow path. Due to the unevenness of the inflow, there is a problem that the paint mist trapping performance in the cleaning liquid exhaust passage is deteriorated. Incidentally, as another type of waste paint treatment apparatus, for example, as shown in Japanese Patent Application Laid-Open No. 60-197262, a cleaning liquid inflow portion into a cleaning exhaust flow passage (that is, a downstream of the cleaning liquid flow-down plate). A cleaning liquid tank with a large weir at the end (corresponding to the end) is provided at the bottom of the booth inner area, and the cleaning liquid tank is filled with the cleaning liquid to fill the cleaning liquid tank with the cleaning liquid tank. There is also a form in which the cleaning liquid inside flows out to the cleaning exhaust flow path from the above weir by overflow, and in this form, since the cleaning liquid is stored in the cleaning liquid tank with the weir,
As described above, it is possible to prevent unevenness in the supply of the cleaning liquid on the upstream side and unevenness in the flowing of the cleaning liquid into the cleaning exhaust flow path due to the unevenness of the falling plate. On the other hand, however, in this other type, the flushing function by the downwashing liquid cannot be expected, and the paint mist that has landed on the washing liquid in the washing liquid tank collects into sludge, or from the inside of the upper booth. Falling paint lumps, or
When the cleaning liquid that has captured the paint mist in the cleaning exhaust flow path is reused as the cleaning liquid that is supplied to the cleaning liquid tank after being separated from the coating material, the remaining paint sludge that has not been completely separated accumulates on the entire cleaning liquid tank. Therefore, there is a problem that the burden of cleaning maintenance on the cleaning liquid tank becomes large. In view of the above circumstances, the main problem of the present invention is to utilize the washing-off function of the washing liquid flowing down in the washing liquid falling plate to the washing exhaust flow path caused by unevenness of the washing liquid supply on the upstream side and unevenness of the flowing down plate. This is to effectively prevent unevenness of the cleaning liquid inflow. A characteristic constitution of a waste paint treatment apparatus for a coating booth according to the present invention is that a cleaning liquid flow-down plate having an inclined posture for causing the cleaning liquid to flow down is provided at the bottom of the booth inner region where spray coating is performed. A configuration is provided on the downstream end side of the cleaning liquid flow-down plate to form a cleaning exhaust flow passage that allows the air discharged together with the excess paint mist from the booth internal region and the flowing-down cleaning liquid from the cleaning liquid flow-down plate to pass through in a combined state. At
The cross section of the cleaning liquid flow-down plate has a groove for cleaning liquid storage at the downstream end, and the groove wall on the cleaning exhaust flow path side in this groove overflows to cause the cleaning exhaust flow from the groove. It is formed in a structure that allows the cleaning liquid to flow out to the passage, and its action and effect are as follows. [Operation] That is, in the above-described characteristic configuration, the entire cleaning liquid supplied on the upstream side is arranged in a tilted posture up to the cleaning liquid reservoir groove formed at the downstream end of the cleaning liquid lowering plate. It is made to flow down in the form of a film-like flow that does not stay along the plate surface of the cleaning plate, and in this process, the cleaning liquid flowing down is caused to adhere to the cleaning liquid flow plate, paint mist falling from the upper booth area, and reused. Rinsing away residual paint sludge contained in the cleaning liquid itself and making it function. In the cleaning liquid reservoir groove formed at the downstream end of the cleaning liquid flow-down plate, with the cleaning liquid stored in the groove, the cleaning exhaust flow passage in the groove is accompanied by the cleaning liquid inflow from the upstream side. In the form in which the groove wall on the side of is a overflow weir, the cleaning liquid is caused to flow from the groove portion to the cleaning exhaust flow channel by overflow from the groove wall. That is, even if there is unevenness in the width of the falling plate due to unevenness in the supply of the cleaning liquid in the width direction of the falling plate on the upstream side and unevenness of the falling plate due to manufacturing errors and the like. As a result of the leveling of the liquid level due to the storage of the cleaning liquid in the groove, the cleaning liquid can be made to flow into the cleaning exhaust passage from the groove in a uniform state in the width direction of the falling plate. [Effects] According to the present invention, due to the function of flushing down the washing liquid flowing down to the groove for holding the washing liquid, sludge of the landing paint mist, lumps of paint falling from the upper booth area, and , The residual paint sludge contained in the reused cleaning liquid itself can be accumulated in the groove portion at the downstream end of the cleaning liquid flow plate, whereby the coating sludge and the falling paint lumps are accumulated over the entire cleaning liquid pan. Compared to a type device, the required cleaning points can be centralized and the burden of cleaning maintenance can be reduced. Further, while making use of the function of flushing down the washing liquid in this way, it is possible to prevent unevenness in the feeding of the washing liquid on the upstream side and unevenness of the washing liquid flowing into the exhaust flow passage for washing due to the unevenness of the downflow plate to supply these washing liquids. Irrespective of unevenness or unevenness of the flow plate, the cleaning liquid can be made to uniformly flow into the flow path of the cleaning liquid in the width direction of the flow plate, so that the paint mist trapping performance in the cleaning liquid exhaust flow path (in other words, discharge from the booth inner area) The paint mist removal performance for air) can be improved. 1 and 2 show a coating booth, in which an object 4 to be coated (an automobile body in this example) is hung by a hanger type conveyor 6 inside a booth 5. In the meantime, a plurality of coating machines 7 installed in the booth apply spray electrostatic coating to the article 4 to be coated. Inside the booth 5, the ceiling outlet 9
Ventilation air is blown downwards from the side wall outlets 10 and obliquely downwards, and the air in the booth along with the excess sprayed paint mist is passed through the lattice floor 11 toward the waste paint treatment device 12 at the bottom of the booth. To discharge. The central control unit controls the operation of the conveyor 6 and the coating machines 7 and the operation for changing the coating color, and the objects to be coated 4 are sequentially sprayed electrostatically by the automatic control by the central control unit. To be done. For spray electrostatic coating, a hanging rod 18 for suspending each object 4 to be coated on the conveyor 6 in order to bring the object 4 suspended and supported by a hanger type conveyor 6 into an electrically insulated state. Each of which has an insulator 19 interposed therebetween, and is automatically connected to the object to be coated 4 which has reached a coating position corresponding to each coating machine 7 by a command from a central control unit. The clamp device 20 is provided on the floor of the booth, and by connecting the clamp device 20, a high positive voltage is applied from the high voltage generator 21 to the object 4 to be coated which is in the insulating and supported state. On the other hand, the spray gun 1 in each coater 7
4 is equipped with an electrode 14a for forming an electric field for inducing the spray paint between the article 4 to which a high voltage is applied and the spray gun 14, and the electrode 14a is electrically connected. It is grounded at. That is, with the spray gun 14 side being the ground side and the article 4 being supported in an electrically insulated state,
A high voltage is applied to the object to be coated 4, and by this,
Particles of the paint sprayed from the spray gun 14 are charged in a forming electric field between the spray gun 14 and the object 4 to be coated, and the charging causes the spray paint to be attracted to the object 4 side to which a high voltage is applied. Thus, the object to be coated 4 is efficiently applied. When a predetermined spray electrostatic coating is applied,
In response to a command from the central controller, the connection of the clamp device 20 is automatically released, and the transfer of the coated object is restarted. The above-mentioned waste paint treatment apparatus 12 cleans the paint mist contained in the exhaust air A from the booth inner area with the cleaning liquid W.
To remove the paint mist from the exhaust air A, and as a concrete structure, as shown in FIG. 1, a pair of cleaning liquid flow-down plates 12A that gently incline toward the left and right central portions of the booth 5. Is provided at the bottom of the booth inner region below the lattice floor 11, and the upstream side of each of the cleaning liquid flow-down plates 12A is supplied with the cleaning liquid W by overflow to the plate surface of the cleaning liquid flow-down plate 12A. A supply gutter 12B is provided, and on the downstream end side of these cleaning liquid flow-down plates 12A (that is, between the downstream end edges of both cleaning liquid flow-down plates 12A), exhaust air A from the booth inner region and both cleaning liquid flow-down plates 12A are supplied. A cleaning exhaust passage 12C is formed to allow the flowing-down cleaning liquid W to pass therethrough. That is, in the course of passing through the cleaning exhaust passage 12C, the paint mist in the exhaust air A is captured by the cleaning liquid W to remove the paint mist from the exhaust air A. In the cross-sectional shape shown in FIG. 1, each of the cleaning liquid flow-down plates 12A has a groove portion 12D for storing the cleaning liquid at the downstream end, and the cleaning exhaust passage 12 in the groove portion 12D.
The groove wall 12E on the C side is overflowed so that the groove portion 12D
The cleaning liquid W for catching the paint mist is made to flow from the cleaning exhaust passage 12C. That is, up to the cleaning liquid reservoir groove 12D, the entire cleaning liquid W supplied on the upstream side is flowed down along the plate surface of the cleaning liquid flow-down plate 12A arranged in an inclined posture in a film-like flow without retention. In this process, the downwashing liquid W is washed off against the paint mist that tends to adhere to the downwashing plate 12A, the paint dregs falling from the upper booth area, and the residual paint sludge contained in the reused washing liquid itself. Make it work. In the cleaning liquid reservoir groove portion 12D formed at the downstream end of the cleaning liquid flow-down plate 12A, the groove portion 12 is formed.
In the state where the cleaning liquid W is stored in D, the cleaning exhaust flow channel 1 in the groove 12D is caused by the inflow of the cleaning liquid from the upstream side.
In the form in which the groove wall 12E on the 2C side is an overflow weir, the cleaning liquid W is caused to flow from the groove portion 12D to the cleaning exhaust flow passage 12C by overflow from the groove wall 12E, so that the flow-down plate on the upstream side is formed. Width direction (Fig. 1
Unevenness in the cleaning liquid supply in the paper depth direction in
Due to the unevenness of the falling plate due to manufacturing error, etc., the groove 12
Even if there is unevenness in the inflow of the cleaning liquid into D in the width direction of the falling plate, the leveling of the cleaning liquid W in the groove 12D causes the cleaning liquid W to be leveled in the width direction of the falling liquid so that the cleaning liquid W is uniform in the width direction of the falling plate. From the cleaning exhaust flow path 12C. [Other Embodiments] Next, other embodiments of the present invention will be listed.・ Painting is performed with the object 4 being stationary, or
It may be performed in any form. The spray gun 14 may be of a type that is sprayed with a human hand, instead of a type that is provided in a coating robot or an automatic coating machine. The booth 5 structure and the type and structure of the conveyor for carrying the article W to be coated may be of any type. The paint used for coating is not limited to a water-soluble paint using water as a main solvent or a metallic paint mixed with metal powder,
It may be powder paint or the like. The target article to be coated 4 may be any body such as a casing of an automobile body or a home electric appliance, or a steel material for various purposes. It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the structures of the accompanying drawings by the entry. [Brief description of the drawings] [Fig. 1] Enlarged cross-sectional view [Fig. 2] Enlarged vertical cross-section [Description of symbols] 5 Booth W Cleaning liquid 12A Cleaning liquid falling plate A Exhaust air 12C Cleaning exhaust flow passage 12D Groove 12E Groove wall [Procedure Amendment 2] [Document Name for Amendment] Drawing [Item Name for Amendment] Figure 1 [Correction Method] Change [Content of Amendment] [Figure 1]

Claims (1)

[Claims] At the bottom of the booth interior where spray coating is performed, a cleaning liquid flow-down plate having an inclined posture for flowing the cleaning liquid is provided, and the excess paint mist is discharged from the interior space of the booth at the downstream end side of the cleaning liquid flow-down plate. A waste paint treatment apparatus for a coating booth that forms an exhaust flow path for cleaning that allows the air to be passed through and the flow-down cleaning liquid from the cleaning liquid flow-down plate, wherein the cleaning liquid flow-down plate, in its cross-sectional shape, A cleaning liquid reservoir groove is formed at the downstream end, and a groove wall on the cleaning exhaust passage side of the groove overflows to allow the cleaning liquid to flow out from the groove to the cleaning exhaust passage. Waste paint treatment equipment at a painting booth.