JP2012120935A - Method and device for treating circulation water of coating booth - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and equipment for treating circulation water of a coating booth which can separate and extract a coating component from coating-collecting circulation water even if the coating booth uses coating regardless of whether the coating is organic solvent system coating or water-based coating.SOLUTION: The method includes a step of adding strong alkali electrolytic water to the coating-collecting circulation water of the coating booth so as to separate and extract the coating component from the coating-collecting circulation water, which can prevent oxidation of the coating-collecting circulation water and rusting of metal caused by low oxidation reduction potential (ORP) of the strong alkali electrolytic water.

Description

  The present invention relates to a method and an apparatus for treating circulating water in a painting booth.

In a painting booth that performs spray painting with a painting gun, a processing device for capturing and processing oversprayed paint is provided.

  Conventionally, in large processing equipment, slats are placed on the floor of the painting booth and pits are provided underneath to keep the circulating water for collecting paint from both sides of the bottom of the slope. A water tank is provided on the floor, and the circulating water for collecting the paint is continuously flowed from the upper part of the vertical water curtain plate.

  In the case of collecting oversprayed paint by circulating paint collecting water, not only organic solvent-based paints but also water-based paints have been diversified and used in recent years.

  As a prior art of the processing method and apparatus of the painting booth circulating water, there exists a thing of Unexamined-Japanese-Patent No. 2006-181503, for example. The purpose of this is to provide a treatment method for circulating water in a painting booth that can easily separate and extract paint components from circulating water for collecting paint even in a painting booth that uses water-based paint. The step of adding an alkaline solution to the circulating water for collecting paint in the paint booth 1, the step of filtering the circulating water to which the alkaline solution has been added to separate it into a filtrate and a residue, It has a step of neutralizing, and a step of reusing the neutralized filtrate as circulating water for collecting paint.

JP 2006-181503 A

  However, it is difficult to separate and extract water-based paint with circulating water such as tap water.

  The present invention provides a coating booth circulating water, a treatment method and equipment capable of separating and extracting the paint components from the circulating water for collecting the paint, even in a coating booth that uses all organic solvent-based paint and water-based paint. The purpose is to provide.

  In order to achieve the above object, the coating booth circulating water treatment method according to the present invention adds strong alkaline electrolyzed water to the coating booth circulating water for collecting paint, and separates and extracts the paint components from the circulating paint collecting water. By providing the step, the oxidation of circulating water for collecting paint and the prevention of metal rust based on the low reduction potential (ORP) of strong alkaline electrolyzed water can be achieved.

  The pH of the strong alkaline electrolyzed water is preferably 12 or more, particularly 13 or more, and more preferably 14 or more. In water-based paints, acidic polar groups such as carboxylic acids are used to disperse resin components in water as a solvent. When strong alkaline electrolyzed water is mixed in the circulating water for collecting paint, the dispersed particles of the paint component resin swell (gelate). In the present invention, strong alkaline electrolyzed water is applied to the circulating water for collecting paint, and then it can be easily separated into a paint component and a water component by filtration.

  As a result of intensive studies by the present inventors, it has been found that neutralization by acid with respect to the filtrate is not necessary by using strong alkaline electrolyzed water instead of using an alkaline solution as in the prior art described above.

  The paint component that has been easily separated is filtered and separated into a filtrate and a residue, so that a part of the filtrate is returned and reused as circulating water for collection, and a part is drained for disposal. After the residue is concentrated and dried, the acid content is modified, and the residue can be used as a secondary resin such as cement as an alkaline component resin. The collection circulating water drained for disposal can be neutralized by reacting with polar groups such as carboxylic acid contained in the paint, and by controlling the contact time, it is possible to make the polarity possible for drainage.

  Strong alkaline electrolyzed water has a strong intermolecular attractive force (electron peeling action), which is a characteristic of the strong alkaline electrolyzed water, which has a bactericidal effect and prevents the electrolytic water itself from decaying or deodorizing. Strong alkaline electrolyzed water has an effect of suppressing the corrosion of the metal by forming a passive film on the metal surface because the dissolved oxygen amount is 1/10 or less of pure water.

  Furthermore, strong alkaline electrolyzed water is a solution with small clusters and a large amount of electrons, so it has excellent hydrophilicity and permeability, so intermolecular force appears when it touches dirt and substrate, and dirt comes from the substrate surface. The peeling action works. For this reason, it is possible to eliminate all the factors such as oxidation, rot, and corrosion that are the cause of the off-flavor, and the entire apparatus of the painting booth is kept under good conditions.

  According to the present invention, many chemicals such as caustic soda and denaturing agents have been devised and used for this purpose. However, all of the examples have problems in safety, economy and efficiency. However, the present invention can solve all of these problems. Even in the case of strong alkaline electrolyzed water of pH 12 or higher used in the present invention, there is no danger even if it touches the skin in terms of safety, and the test results have been proved that it is safe even for eye drops by rabbits.

  According to the present invention, even in a paint booth that uses an organic solvent-based paint and a water-based paint, the paint booth circulating water and a treatment method capable of separating and extracting paint components from paint collection circulating water, Equipment can be provided.

It is sectional drawing which showed an example applied to "the method of using strong alkali ion water for the circulating water of a painting booth" which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a medium / small-sized paint booth according to the embodiment, a strong alkaline ionized water generating device, and a water supply system.
As shown in the figure, the painting booth includes a water tank 1, a scrubber 2, and a ceiling panel 3.

  The structure of the painting booth in the preceding paragraph is generally called an open booth because there is no panel 4 on the opposite side of the scrubber 2, but the panel 4 is provided on the opposite side of the scrubber, the ceiling surface 3 and the ceiling filter 5 are provided, In the meantime, the air rectified in the rectifying chamber 6 that guides the conditioned air from the air supply device passes through the ceiling filter 5 and is blown downward to the painting chamber 7.

  The oversprayed paint (spray paint) overflows from the scissors 9 on the outer upper part of the scrubber, and when the circulating water for collection that has flowed out falls down the water film plate 8, the water filled in the water tank and the water film plate 8 The air and the circulating water for collection are mixed and sucked in powerfully toward the inside of the scrubber 2 from the gap 10 provided at the lowermost part. An exhaust fan 13 is provided at the top of the scrubber, but the capacity is sufficiently stirred in consideration of the air resistance of the eliminator (collision plate) 12 provided in the scrubber so as not to wind up excessive water. .

  In the figure, A indicated by a two-dot chain line is an object to be coated, and in the case of work by automatic conveyance, the object A is suspended on the overhead conveyor B and moved or stopped at the center of the painting booth. The object A is painted by spraying. At that time, the paint that has not adhered to the object A is sucked from the lowermost gap 10 of the water film plate 8 on the descending airflow discharged from the air supply filter provided above the painting booth as described above. The swirl plate 11 below the scrubber causes a violent stirring action and is collected in water.

  Intake air to the fan 13 is vigorously agitated by the spiral portion D formed by the spiral plate 11 and the gap plate 10, and the mixed water and air collide with the eliminator (collision plate) 12 in the scrubber, and the momentum decreases. The collected circulating water collects and drops as water droplets, and the air is guided by the fan 13 and the exhaust duct and exhausted to the outdoors. The collected circulating water that has been separated and dropped flows from the dropping port 14 to the water tank 1.

  A part of the water tank 1 is provided with three weirs. The first weir 15 is attached to the bottom of the water tank, and is lowered by about 1/4 from the water surface. The second weir 16 is attached with the lower end at a position where the upper end of the second weir 16 rises from the bottom of the water tank by about 1/4. The third weir has the same shape as the first weir, but each of the three weirs is positioned so that the circulating water for collection can flow over and submerge.

  Downstream of the third weir 15, there is an intake port 17 for a water pump 19, which is sent to the trough 9 of the above (0020) via pipes 18 and 20 and used as circulating water for collection.

  The collected circulating water is blocked by 16 weirs that are denatured to float, and the one that is denatured by sediments is blocked by 15 weirs and stays upstream, and is collected automatically or manually.

  The strong alkaline electrolyzed water generator 22 supplies strong alkaline electrolyzed water having a pH of 12 or more to the storage tank 23. The storage tank is equipped with a sensor for controlling the upper end and the lower end of the liquid level and is always full.

  When the circulating water exhausts the air in the scrubber 2 by the fan 13, the fine water droplets are partially exhausted together with the air or naturally evaporated to reduce the amount. The amount is 10-20% of the capacity of the water tank per day, and the reduced amount is controlled with a ball tap so as to always replenish strong alkaline electrolyzed water pH 12 or more and maintain the position of the water surface.

  As described above, according to the method and apparatus for treating circulating water according to the present embodiment, the strongly alkaline electrolyzed water generating apparatus and the storage tank are a part of the painting booth, and are collected in a part of the tank. This refers to a device in which a portion called a floating trough having a plurality of weirs for controlling the flow of circulating water and a fresh water tank 21 having a ball tap for controlling a stable water surface height communicate with the water tank.

  The embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

1 Water tank 14 Drop port 2 Scrubber 15 Weir 1
3 Ceiling 16 Weir 2
4 Panel 17 Intake 5 Filter 18 Piping 6 Rectification Chamber 19 Pump 7 Painting Chamber 20 Piping 8 Water Film Plate 21 Fresh Water Tank 9 ２２ 22 Generator 10 Gap 23 Storage Tank 11 Swirl Plate A Coated
12 Eliminator B Overhead conveyor 13 Exhaust fan C Paint gun

Claims (5)

  A method for treating circulating water in a coating booth, comprising the step of adding strong alkaline electrolyzed water to circulating water for collecting paint in a painting booth, and separating and extracting the coating material components from the collected paint circulating water.   The processing method of the coating booth circulating water of Claim 1 which adds strong alkaline electrolyzed water of pH12 or more to the said circulating water for paint collection.   The processing method of circulating water of a coating booth according to claim 1 or 2, wherein the paint component separated and extracted is subjected to concentration treatment and drying treatment and then discarded. A device for generating strong alkaline electrolyzed water;
An exhaust fan exhausting the painting booth,
Means for stirring the strong alkaline electrolyzed water and the oversprayed paint by the air flow formed by the exhaust fan, and collecting the paint in the strong alkaline electrolyzed water;
A water tank for storing the strongly alkaline electrolyzed water;
Separation means for separating the solid component of the paint from the strong alkaline electrolyzed water in the water tank;
A pump for circulating the strong alkaline electrolyzed water;
A painting booth circulating water treatment device.   The processing apparatus of the coating booth circulating water of Claim 4 whose pH of the said strong alkaline electrolyzed water is 12 or more.

Images