JP2001096209A - Wet scrubber and coating material spray booth equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the capturing performance for coating material particles contained in waste gas flow f compared to the conventional one only by simply modifying an existing wet scrubber to facilitate the application to an existing working spray booth 20 in the wet scrubber provided with a venturi shaped structural part 1, through which the waste gas flow f is passed and accelerated and on the inside surface 4a, 4b of which water w is supplied and flows down. SOLUTION: A venturi throat part 2 in the wet scrubber having the structure is provided with a rebounding means (e.g. a ring of circular tube) for receiving the water w flowing down on the inside walls 4a and 4b of the venturi shaped structural part 1, changing the flow direction from horizontal to upward and releasing toward the flow passage center zone s of the gas flow and is structured to form a water group 5 of fine drops in the flow passage center zone s.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet scrubber capable of removing liquid or solid particles contained in an air stream by taking them into a liquid (usually water) for trapping particles, and a wet scrubber. Equipped with a wet scrubber,
The present invention relates to a paint spray booth capable of catching and removing paint particles and the like (paint mist) contained in a flow of exhaust air from a spray chamber. It should be noted that the wet scrubber and the paint spray booth of the present invention are typically used for painting an automobile body and automobile parts in an automobile assembly factory.

[0002]

2. Description of the Related Art Conventionally, in a paint spray booth for painting an automobile body or the like, in order to remove paint particles contained in the exhaust stream from the exhaust stream, usually, a wet method, that is, a contaminated exhaust stream is subjected to a liquid method. (Usually, water) is mixed by bringing it into contact with (usually, water), whereby the paint particles contained therein are taken in and captured by a liquid, and a wet scrubber is provided as equipment for this purpose. And
Of these wet methods, typically, the exhaust gas is accelerated by passing it through a throttle structure called a venturi, and water for trapping paint particles is supplied to the inner wall of the structure to flow down. Then, a method is used in which the falling water is atomized into small droplets by an accelerated exhaust stream, and the paint particles in the air stream are captured and removed by stirring and mixing with the exhaust stream. U.S. Pat. Nos. 5,074,238 and 4,664,060 suggest improvements in this type of wet scrubber technology. In addition, the present applicant has recently proposed a vortex-type wet scrubber as an improvement of a wet scrubber having a venturi-type structure (Japanese Patent Application No. 11-040105). This is because the accelerating cone corresponding to the Venturi structure, the mixing chamber, the vortex chamber, and the spiral are integrally connected.First, the accelerated exhaust gas flows through the accelerating cone and flows down on the inner wall of the accelerating cone. The impinging water is then mixed with water and then swirled to form a vortex, thereby taking in the particles in the airflow into the water, decelerating them, and then releasing them out. During this process, the pressure loss can be minimized, and the efficiency of capturing particles can be improved.

[0003]

However, although the prior art discloses many wet scrubbers as described above, there is still room for improvement. Typical wet scrubbers generally have poor mixing efficiency of water for trapping paint particles with the exhaust stream passing through the venturi structure,
It is required to further enhance the performance of capturing paint particles. Here, it is conceivable to increase the capacity of the exhaust fan and increase the passage speed (pressure loss) of the exhaust flow. However, this method causes intense noise and increases inefficient energy consumption. Since it will be used,
There are certain limitations to the improved means of increasing exhaust capacity. On the other hand, the above-mentioned vortex-type wet scrubber is improved in terms of pressure loss, energy consumption, noise, etc., but is a relatively large facility, so that the existing paint sprayer currently operating is used. When replacing the wet scrubber with a wet scrubber already installed in the booth, it may be difficult to install the wet scrubber due to the internal structure of the scrubber room and the size of the extra space. Therefore,
In existing paint spray booths, particularly in a paint spray booth where it is difficult to install a vortex-type wet scrubber, it is possible to improve the performance of capturing paint particles contained in the exhaust stream, and further reduce the energy waste. However, development of other means was desired.

Accordingly, the present inventor has conducted intensive studies on existing wet scrubbers, particularly wet scrubbers having a venturi-shaped structure, in order to improve the performance of trapping paint particles in the exhaust stream. Surprisingly, in the venturi-throat portion having a reduced diameter in the venturi-shaped structure, a suitable bounce means such as a bounce plate extending from the inner wall of the structure is provided with a suitable bounce means over the entire circumference of the throat portion. When attached to a required location, during operation of the wet scrubber, the water flowing down on the inner wall of the venturi-shaped structure hits the rebound means, the flow is changed upward, and is discharged toward the central area of the flow path of the air flow. And, in the central area of the channel, contact with an airflow passing therethrough forms microdroplets or mist-like water groups, and as a result, Mixing with the exhaust flow is further promoted, found that acquisition performance of the paint particles contained in the exhaust stream is an effect that significantly improved, and, here, the present invention has been completed.

Accordingly, it is an object of the present invention to provide a wet scrubber having a venturi-shaped structure,
The trapping performance of the particles contained in the airflow is significantly improved compared to the past, and the rise in pressure loss during operation is small, especially for existing wet scrubbers. Accordingly, it is an object of the present invention to provide a wet scrubber which also has an advantage that a sufficient improvement can be achieved by simply performing the above-mentioned method, and the application to an already-used paint spray booth is very easy. It is another object of the present invention to provide an improved paint spray booth with the above-described wet scrubber, which has a remarkable performance of capturing paint particles contained in an exhaust stream, and consumes less energy. . The other objects of the present invention can be easily understood from the following description or based on matters obvious from the description.

[0006]

SUMMARY OF THE INVENTION The present invention more particularly comprises a venturi-shaped structure through which an air stream is accelerated, and wherein water for trapping particles contained in the air stream is provided. A wet scrubber that is supplied on the inner wall of the structure and flows down on the wall, wherein the flow-down water is received at a venturi throat portion having a reduced diameter in the Venturi-shaped structure, and the flow of the water is reduced from the horizontal. Bounce means for deflecting upward and discharging the downflow water toward the central area of the flow path, thereby forming a water group of microdroplets in the central area of the flow path, About wet scrubber. More specifically, in one aspect of the present invention, the rebound means extends upward from the inner wall of the venturi-shaped structure over the entire circumference of the venturi throat part or at a necessary point. In another embodiment, the bounce means is constituted by a bounce tube or a rod fixed to the inner wall of the Venturi-shaped structure part over the entire circumference of the Venturi throat part or at a necessary place. You. And
A more preferred embodiment of the present invention relates to the above wet scrubber, wherein the upper surface of the bounce plate is inclined at an angle of 30 ° to 60 ° with respect to the horizontal plane. Another more preferred embodiment relates to the above wet scrubber, wherein the bounce tube or rod has an outer diameter of 1.5 cm to 15 cm when the venturi throat has an inner diameter of 30 cm to 300 cm. According to another aspect of the present invention, there is provided: a) a spray chamber for spray-coating an object; and b) a flow plate disposed below the spray chamber and having an opening. C) a wet scrubber of any of the above embodiments, provided below the flow plate of the scrubber chamber so that the top of the venturi-shaped structure fits into the opening; d) Water supply means for supplying water for the capture of paint particles onto the flow plate and flowing onto the inner wall of the venturi-shaped structure of the wet scrubber; ande) exhaust air containing paint particles to be removed, A paint spray booth comprising: an exhaust mechanism for drawing out from a spray chamber through the wet scrubber.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wet scrubber having a venturi-shaped structure (a throttle structure called a venturi). The airflow (exhaust flow from the spray chamber in a paint spray booth) is accelerated through the venturi-type structure, and water (in a paint spray booth, water flowing from a flow plate) Is supplied to the inner wall of the Venturi-shaped structure and flows down, and at and around the Venturi throat portion having a reduced diameter, the flowing water is atomized into small droplets by the accelerated airflow, and is stirred and mixed with the accelerated airflow. In addition, the particles in the air stream are taken in the flowing water and removed. During the operation of the paint spray booth, the water is continuously supplied to the inner wall of the wet scrubber, so that the mixing of the flowing water and the accelerated air flow is continuously performed in the venturi-type structure,
The removal of the particles in the air stream to the running water is performed continuously.
In a wet scrubber installed in a paint spray booth, the throat portion of the venturi-shaped structure usually has a rectangular opening having a length of about 30 cm to about 80 cm in length and width, respectively. In addition, a wet scrubber having a venturi throat portion having an elongated rectangular opening having a width of about 20 cm and a length of about 150 cm has also been put to practical use. Further, the throat portion of the venturi-shaped structure has, for example, a radius (major axis, minor axis) of about 30 cm to about 80 c, respectively.
It may be a circular or elliptical opening having a length of m.

As shown in FIG. 1, the wet scrubber of the present invention has a venturi throat portion 2 which is reduced to an opening having the above-mentioned size in a venturi-shaped structure portion 1 and has a bounce means 3, for example, as shown in FIG. As shown in the figure, a flange-shaped member that is warped upward from the inner wall 4 of the structure is provided over the entire circumference of the throat portion 2 or at a necessary portion thereof. The bounce means 3 receives the falling water w flowing down on the inner wall 4 of the venturi-shaped structure 1, turns the flow upward from the horizontal, and transfers the water w to the airflow (indicated by an arrow f in the figure). Is discharged toward the central region s of the flow path. Therefore, during operation of the wet scrubber, the water w flowing down on the inner wall 4 of the venturi-shaped structure portion 1 is discharged to the central area s of the airflow by the rebounding means 3 at the venturi throat part 2, In the road center area s,
A water population 5 of microdroplets is formed. Generally, since the venturi throat part 2 is a part whose diameter is reduced most, the airflow is
At the time of passing through the throat region 2, the vehicle is accelerated to the highest speed. Moreover, in general, like the flow of Poiseuille, the velocity of the airflow passing through the surface of the inner wall 4 and the peripheral area thereof is the lowest among the flow paths in the venturi-shaped structure 1, and the velocity of the passing airflow is lower than the inner wall 4 As the distance from the surface increases, the velocity increases further, and the velocity of the airflow passing near the center of the flow path central area s becomes the highest. Therefore, the wet scrubber according to the present invention is provided with the flowing water w
Is discharged into the central region s of the flow passage through which the higher-speed or highest-speed airflow passes, where it comes into contact with the airflow. That is, in the present invention, the water discharged into the central region s of the flow of the airflow becomes a water group 5 of fine microdroplets due to the contact with the extremely high-speed airflow, and violently interacts with the passing airflow. Can be mixed. In contrast, in a wet scrubber having a conventional Venturi-shaped structure, water flowing down on the inner wall of the structure at and near the Venturi throat portion flows on the surface of the inner wall and a peripheral area close thereto. The gas-liquid mixture was mainly in contact with the airflow. As described above, the airflow passing through the venturi-shaped structure is considered to be similar to the flow of Poiseuille, and the speed of the airflow passing through the peripheral area near the inner wall is determined by the airflow passing through the central area of the airflow channel. Lower than the speed. Therefore, this type of conventional wet scrubber has a structure in which water is mainly mixed with water at a lower velocity portion of the passing airflow, so that the gas-liquid mixing efficiency is reduced. It was lower. In other words, from another aspect, the wet scrubber having the conventional structure has a structure in which the airflow passing through the venturi-shaped structure portion includes:
Most of the airflow passing through the central region of the flow path hardly comes into contact with the water flowing down on the inner wall of the structure, that is, passes through the venturi-shaped structure without sufficient gas-liquid mixing. That was the configuration. In particular, in a conventional wet scrubber in which the venturi throat has a wide opening, the tendency of the air flow to pass through without mixing with the water on the inner wall is increased. Conventionally, paint spray booths in automobile factories equipped with conventional wet scrubbers have traditionally used methods such as increasing the suction force of air to the wet scrubber to improve the ability to trap particles in the airflow, or using a venturi-type structure. In some cases, a method was adopted in which the internal shape was changed to such a shape that the average flow velocity of the entire passing airflow increased, but according to these methods, the pressure loss increased remarkably, and paint particles were removed. This causes a problem that the energy consumption required for the vehicle is significantly increased. On the other hand, in the wet scrubber of the present invention, the water flowing down on the inner wall 4 of the Venturi structure 1 at the venturi throat part 2 and its vicinity,
Forcibly released into the center area s of the air flow farther away,
Water is brought into contact with the air flow in the entire flow path of the air flow, and in particular, is brought into contact with the remarkably high-speed air flow in the central region s of the flow path, whereby gas-liquid mixing is performed. Therefore, in the wet scrubber of the present invention, the water w flowing down on the inner wall 4 of the venturi structure 1 is caused to flow through the airflow passing through the venturi structure 1 and the flow path from the lower speed portion of the flow path peripheral area. Contact mixing is performed throughout the higher speed portion of the central region s, and therefore, the efficiency of gas-liquid mixing is very high. In other words, in another aspect, in the wet scrubber of the present invention, the airflow passing through the venturi-shaped structure 1 is particularly passed through the central area s of the flow path by the provision of the rebound member 3. The flowing air stream also comes into contact with the released water droplets 5 and the water droplets 5 are sufficiently mixed with water. Therefore, even in the case of a wet scrubber in which the venturi throat portion 2 has a wide-mouth opening, the occurrence of a situation in which the air flow passes through the venturi-type structure portion 1 without contact with water and without mixing is more effectively prevented. Is done. As described above, the wet scrubber of the present invention has a structure capable of sufficiently mixing the entire airflow with water, and therefore, the performance of capturing particles in the airflow is significantly improved.

[0009] The bounce means receives, at the venturi throat portion, downflow water on the inner wall of the venturi-shaped structure, diverts the flow upward from horizontal, and discharges the downflow water toward the central region of the airflow channel. However, as long as the configuration allows the water group of the microdroplets to be formed in the central region of the flow channel, the shape and structure thereof are not particularly limited. As the rebound means, for example, a rebound plate (which may be either a flat plate or a curved plate) extending upward from the horizontal extending from the inner wall of the Venturi-shaped structure, or fixed on the inner wall of the Venturi-shaped structure And a rebound tube or rod (which may be any of a round shaft, a round tube, a square shaft and a square tube). These rebound means are provided over the entire circumference of the venturi throat site or where necessary. From the viewpoint that the flowing water can be discharged to the central region of the airflow at a longer flight distance, the upper surface of the bounce plate is more preferably at an angle of 30 ° to 60 ° with respect to the horizontal plane, most preferably 45 °. At an angle. In addition, from the same viewpoint, the venturi throat part has an inner diameter of 30 cm.
More preferably, the bounce tube or rod has an outer diameter of 1.5 cm to 15 cm when having a size of
cm.

A paint spray booth used for automatic coating of an automobile body or the like generally comprises a top air supply chamber, a center spray chamber, and a bottom scrubber chamber. A flow plate is stretched in the scrubber chamber, and on the upper surface thereof, water for trapping particles is continuously supplied to an opening in the center of the flow plate. . A wet scrubber is provided at the opening of the floor plate. Wet scrubbers are usually
They are arranged linearly in the longitudinal direction of the paint spray booth. The scrubber chamber is connected to the exhaust duct and through it communicates with the fan arrangement of the exhaust mechanism. Accordingly, the operation of the exhaust mechanism draws the air in the paint spray booth to the exhaust fan, and the exhaust flow from the spray chamber is discharged into the scrubber chamber through the wet scrubber, and is guided to the exhaust fan. On the other hand, water for trapping the paint particles in the exhaust gas flows from the floor plate into the wet scrubber, where it is mixed with the gas stream and gas-liquid and discharged into the scrubber chamber. Thus, paint particles in the exhaust stream are taken up in the water through such a process and removed. Thus, the wet scrubber of the present invention can be applied to a paint spray booth having such a general configuration. Accordingly, in another aspect, the present invention provides a) a spray chamber in which spray coating of an object is performed; and b) a flow plate disposed below the spray chamber and having an opening therein. C) a scrubber chamber provided; c) below the flow plate of the scrubber chamber, the above wet scrubber equipped with a top of a venturi-shaped structure to fit the opening; d) trapping of paint particles. Water supply means for supplying water to the flow plate and flowing onto the inner wall of the venturi-shaped structure of the wet scrubber; ande) exhausting air from the spray chamber containing paint particles to be removed. A paint spray booth comprising an exhaust mechanism for withdrawing through a wet scrubber.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be clarified by describing embodiments embodied in the drawings as the best embodiments of the present invention.

Embodiment 1 FIG. 7 illustrates the interior of a paint spray booth 20 used for spray painting a car body in a car factory. Booth 20 has three smaller compartments:
It is divided into an air supply chamber 21 at the top, a spray chamber 22 at the center, and a scrubber chamber 23 at the bottom. The booth 20 is connected to an exhaust duct 24, which is led to an exhaust fan mechanism (not shown). A filter 25 is provided in the air supply chamber 21.
However, it is stretched and fixed at the boundary between the compartment and the spray chamber 22. The air supply chamber 21 is also provided with a bag filter 26. Therefore, dust in the air is filtered by the bag filter 26.
After being removed by the filter 25 and the air, the temperature- and humidity-controlled air is supplied to the spray chamber 22 as a vertically descending airflow. The spray chamber 22 has a coating robot 2 for performing automatic spray coating on the vehicle body 27.
Nine or other coating devices are typically provided on each of the left and right sides of the path on which the vehicle body 27 is transported on the carriage 28. Therefore, the surplus paint that has not adhered to the vehicle body 27 during painting floats in the air as paint mist. In the scrubber chamber 23, as shown in an enlarged manner in FIG. 8, a flow plate 30 is horizontally stretched at an upper portion thereof, and an opening 31 is formed at the center of the flow plate 30. . The wet scrubber 1 of the present embodiment has the
Is attached to the flow plate 30 by being fixed to. Therefore, air (including paint mist) in the spray chamber 22 is sucked by the operation of the exhaust fan mechanism,
As a descending exhaust flow, it is introduced into the wet scrubber 1, passes through the wet scrubber 1, and is discharged from the outlet 9 into the lower space of the scrubber chamber 23. On the other hand, on the left and right sides of the flow plate 30,
And water supply pipes 33, 33 are respectively introduced into the tubs 32, 32. Therefore,
By operation of a pump (not shown), water is supplied to the left and right tubs 32,
32 respectively. And water is left and right tub 3
It overflows from 2, 32 and flows on the flow plate 30,
A shallow puddle (W in the figure) is formed, and then, near the center thereof, the periphery 15 of the entrance 8 of the wet scrubber 1 is formed.
Overcoming and flowing into it. This water W is a liquid for trapping paint particles contained in the exhaust stream.
The flow plate 30 has, for example, about 20 to about 30.
The openings 31... Of the holes are formed in a line in the longitudinal direction (not shown) of the paint spray booth 20 at equal intervals of, for example, 0.5 m to 1.5 m. The wet scrubbers 1 of this embodiment are respectively mounted. Therefore, the wet scrubber 1 of this embodiment
Are arranged in the paint spray booth 20 in a line in the longitudinal direction. Also, the scrubber room 23
Are connected to the exhaust duct 24 and communicate with the exhaust fan mechanism through the exhaust duct 24. The scrubber chamber 23 has a drain 3 at the bottom below the outlet 9 of the wet scrubber 1.
4 is provided, in which the water containing the paint discharged from the wet scrubber 1 falls and collects. Also,
Several mist separators 35 are attached to the air flow passage communicating with the exhaust fan mechanism.

Next, the details of the wet scrubber 10 of the present embodiment, which is used to capture and remove paint particles contained in the exhaust stream from the spray chamber 22, will be described. As shown in FIGS. 5 and 6, the wet scrubber 10 includes a venturi-shaped structure 1, a mixing unit 11 connected to a lower side of the structure 1, and a horizontally connected side of the mixing unit 11. And a speed reduction unit 12. The venturi-shaped structure 1 comprises a throttle structure, called a venturi, through which the exhaust flow f from the spray chamber 22 is accelerated, and is shown in FIGS. 5 and 6 and in enlarged FIGS. 3 and 4. Thus, at the upper end, there is an entrance 8 of a large round hole, and at the bottom thereof, a venturi throat part 2 whose diameter is reduced most as a part corresponding to the exit. Entrance 8
Is fixed to the flow plate 30 by being folded outward and locked in the opening 31. The venturi-shaped structure 1 is, as shown in these figures,
It is divided into an upper portion 1a extending below the entrance 8, a central portion 1b further extending to the throat portion 2, and a lower portion 1c further extending vertically below. Central part 1b and lower part 1
c are covered with a cover plate 14 around them. The central portion 1b is stably supported on a shelf 18 provided inside the cover plate 14 by locking a flange 19 formed on the outside thereof. The lower end of the central portion 1b, that is, the opening in the venturi throat region 2 is a circular opening having a diameter of about 40 cm to about 80 cm. That is, as shown in the figure, the venturi-shaped structural portion 1 is an inner wall having a shape close to the inner surface of the cylinder, and the inner walls 4a, 4b, 4c each having a configuration in which the cross-sectional area of the opening decreases from the upper portion 1a to the lower portion 1c. Having. Therefore, the venturi-shaped structure 1 is accelerated by the suction of the exhaust fan mechanism when the exhaust flow f from the spray chamber 22 passes through it, and the speed of the exhaust flow f is reduced by the venturi throat having the smallest diameter. When passing through the site 2, it is the fastest, while the water W on the flow plate 30 climbs over the periphery 15 of the inlet 8 (p represents the flow of the water in FIG. 3) and the venturi-shaped structure 1 Supplied inside the inner wall 4a
Up and then down on the inner wall 4b (in FIG. 2, w is
A falling water film flowing down on the inner wall 4a and the inner wall 4b of the structure 1 is shown. Then, in the vicinity of the venturi throat region 2, the flowing water w collides with the below-mentioned rebound plate 6, is discharged as fine droplets, and then falls into the mixing unit 11 (see FIG. 2). . In addition, a pair of right and left adjusting plates 13, 13 is attached to a lower portion 1 c of the venturi-shaped structure portion 1 as a member for controlling a passing speed of the exhaust flow f. The adjusting plates 13 and 13 are curved plates having a shape close to a part of the cylindrical peripheral surface, and are provided in such a posture that their inner surfaces face each other and their side edges overlap each other. In FIG. 3, a hatched portion indicated by a two-dot chain line indicates an overlapping portion of the adjustment plates 13 and 13. The adjusting plates 13 and 13 are rotatably suspended around the fulcrums 16 and 16 and can be opened and closed by operating the adjusting screw member 17. In FIG. 3, a solid line 13 indicates the adjustment plates 13, 13 in an open state, and a dashed line 13 indicates the adjustment plates 13, 13 in a closed state. Therefore, the adjusting plates 13, 1
3 can be tilted inward or outward, and this tilt can freely change the cross-sectional area of the flow path downstream of the throat region 2. Therefore, by increasing or decreasing the cross-sectional area of the flow path by tilting the adjusting plates 13, 13, the speed of the exhaust flow f toward the mixing unit 11 can be controlled to be high or low. The mixing section 11 is a chamber that forms a pool (not shown) at the bottom inside thereof, and has a configuration in which water that has fallen from the vicinity of the throat portion 2 accumulates in the pool. Venturi throat region 2 in mixing section 11
The exhaust flow f that has passed through is further configured to collide with the water accumulated in the pool, thereby further promoting gas-liquid mixing. Thereafter, the mixture of the exhaust stream f and the water of the fine droplets is guided to the speed reduction unit 12 while changing the direction of the flow. At this time, the curtain-shaped water flow falling from the venturi-shaped structure unit 1 (see FIG. (Not shown). In this way, the gas-liquid mixing of the exhaust stream f and the water proceeds efficiently, and the paint particles and the like contained in the exhaust stream f are taken in the water in the form of fine droplets or mist. The speed reduction unit 12 is a cylindrical duct connected to the side of the mixing unit 11, and has a structure in which the cross-sectional area of the opening increases toward the outlet 9 from a portion connected to the mixing unit 11. . The mixture of the exhaust flow f and the water guided from the mixing unit 11 is decelerated while flowing through the reduction unit 12, and the exhaust flow f mixed with the water in the form of fine droplets is mixed.
After the speed becomes sufficiently low, the scrubber chamber 23
And a small amount of water that is not sufficiently mixed with the exhaust stream f in the mixing section 11 and water that has fallen in the reduction section 12 due to the deceleration of the exhaust stream f in the reduction section 12,
The fluid flows out from the outlet 9 along the inner wall surface of the speed reduction unit 12.
Thus, the exhaust stream f discharged from the outlet 9 of the wet scrubber 1 is one in which paint particles and the like contained therein have already been removed. The air is discharged to the outside air through the duct 24.
On the other hand, the water flowing out from the outlet 9 of the wet scrubber 1 is
Although it contains and contains paint particles and the like in the exhaust stream f, it falls to the drain 34 (FIGS. 7 and 8) and is thereafter collected.

In this embodiment, FIGS.
As shown in detail in FIG. 2, in the venturi throat portion 2 having a reduced diameter, a bounce means 6 formed of a ring of a round pipe is provided over the entire circumference of the throat portion 2. As shown in FIG. 9, the bounce means 6 uses a putty 40 to form a structure 1b on the inner wall 4b of the venturi-type structure 1.
And the structure 1c. The rebound means 6 is a ring of a round tube having an outer diameter of about 2 to 6 cm (diameter:
As shown in FIG. 9, the inner wall 4 of the venturi-shaped structure 1 is inclined at 45 °.
The tangent line m, which is fixed on b and extends perpendicularly to the surface of the inner wall 4b, is configured so as to form an angle of 45 ° with the horizontal line n. In the figure, an angle α represents an intersection angle between a tangent line m and a horizontal line n. Therefore, the rebound means 6 is provided with the flowing water w flowing down on the inner walls 4a and 4b of the venturi-shaped structure 1.
To change the flow upward from the horizontal, and discharge the flowing water w at the intersection angle α (45 °) toward the flow path central area s of the airflow (indicated by the arrow f in the figure). can do. Therefore, during operation of the wet scrubber 10, the flowing water w on the inner wall 4 hits the bounce means 6 of the circular ring in the venturi throat part 2, and is discharged to the central area s of the flow path of the air flow, and In the area s, a water group 5 of microdroplets as shown in FIG. 2 is formed. Therefore, the wet scrubber 10 of the present embodiment is
Water w flowing down on the inner wall 4 of the venturi-shaped structure 1 is discharged into the central area s of the flow path of the exhaust flow (indicated by the arrow f),
Then, a water group 5 of fine droplets is formed, and the central area s of the flow path is obtained.
May be brought into contact with the faster or highest velocity air stream f passing through and may be mixed vigorously. In particular, in the present embodiment, since the water w flowing down on the inner wall 4b of the structure portion 1 is discharged toward the central area s of the exhaust flow at the intersection angle α of 45 °, the flowing water w is the most. Flying far, therefore, near the center of the flow path central area s, the contact mixing between the water group 5 of fine droplets and the exhaust flow f effectively proceeds. In short, in the wet scrubber 10 of the present example, the flowing water w flows through the venturi structure 1 (indicated by an arrow f).
And from the lower speed portion of the flow channel peripheral region to the higher speed portion of the flow channel central region s, the gas-liquid mixing efficiency becomes very high. In other words, in the present wet scrubber 10, the provision of the rebound member 6 also causes an airflow portion (shown by an arrow f) passing through the venturi-shaped structure portion 1 to pass through the central region s of the flow passage. Contacting the water group 5 which has bounced off the member 6 and turned into fine droplets, so that mixing with water is sufficiently achieved, so that the air flow passes through the venturi-type structure 1 without contact with water and without mixing. The occurrence of a situation is more effectively prevented. As described above, the wet scrubber 10 of this example is
In the method, the performance of capturing paint particles in the exhaust stream f is significantly improved. In addition, the effect of improving the trapping performance is advantageous because the existing wet scrubber having the venturi-shaped structure 1 can be obtained only by providing the rebound means 6.

Test Example The above-mentioned improvement effect was obtained with respect to the existing wet scrubber.
In the case of the first embodiment in which the rebounding means 6 formed of a circular ring is provided, and in the case of the conventional example in which the rebounding means 6 is not provided, the results of the following comparison experiments are also confirmed. The experiment was performed by comparing the conventional example with the example 1 when the same automatic coating was performed using a general-purpose metallic paint in the spray chamber 22. FIG. 11 and FIG. 12 are photographs showing the state of the venturi throat part during the operation of both wet scrubbers of the conventional example and the first example, respectively. From the comparison of these photographs, the wet scrubber 10 of Example 1 was obtained.
In the operation, unlike the conventional wet scrubber, it can be easily understood that minute droplets or mist-like water groups are formed over a much wider range at the opening of the venturi throat region 2.

Embodiment 2 In the wet scrubber and the paint spray booth of this embodiment, instead of the bounce means 6 comprising a ring of a round tube used in the first embodiment, a bounce plate 7 shown in FIG. 10 is used as the bounce means. , The venturi throat portion 2 having a reduced diameter is provided over the entire circumference of the throat portion 2. As shown in the figure, the bounce plate 7 is fixed on the inner wall 4b of the Venturi-type structure portion using a support plate 41 at a position near the boundary between the structure portion 1b and the structure portion 1c so as to face upward from the horizontal. It consists of a flat plate. The upper surface of the bounce plate 7 (m is an extension of the upper surface in the figure) is perpendicular to the surface of the inner wall 4b (inclined at an angle of 45 °) and 45 ° to the horizontal line n. It is configured to make an angle of °. In the figure, the angle α represents the intersection angle between the extension line m on the upper surface and the horizontal line n. Accordingly, the bounce plate 7 receives the flowing water w flowing down on the inner walls 4a and 4b of the venturi-shaped structure, changes the flow upward from the horizontal, and forms the flowing water w at an angle of the intersection angle α (45 °). Thus, the exhaust gas (indicated by an arrow f in the drawing) can be discharged toward the central region of the flow path. Therefore, during the operation of the wet scrubber of the present example, the flowing water w on the inner wall 4 hits the bounce plate 7 at the venturi throat part 2, the flow changes upward, and is discharged into the central area of the flow path of the airflow. In the central area, a water group 5 of microdroplets as shown in FIG. 2 is formed. Although other configurations are not shown in detail, the first embodiment
As a wet scrubber and paint spray booth. Thus, also in the wet scrubber of the present embodiment, in the central area of the flow path of the exhaust flow, the water group of fine droplets is brought into contact with the faster or highest velocity airflow passing through the central area of the flow path, and violently. Can be mixed. Therefore,
In the wet scrubber of the present embodiment, as in the case of the wet scrubber 10 of the first embodiment, the performance of capturing the paint particles contained in the exhaust stream f from the spray chamber 22 of the paint spray booth 20 is much higher than before. A simple modification of the existing wet scrubber with the bounce plate 7 can be achieved with sufficient improvement, and therefore can be easily applied to an existing paint spray booth. It has the advantage of being

[0017]

As described above, according to the present invention,
In a wet scrubber having a venturi-shaped structure, the ability to capture particles contained in the airflow, particularly paint particles contained in the exhaust stream from the spray chamber of the paint spray booth, has been significantly improved compared to the past, In addition, an increase in pressure loss during operation of the wet scrubber can be reduced to a level that does not cause a problem, and an effect of being excellent in energy waste can be obtained. In particular, according to the present invention, for existing wet scrubbers, it is possible to achieve sufficient improvement only by making simple modifications, and
It also has the advantage that it is very easy to apply to an already used paint spray booth. Further, according to the paint spray booth of the present invention, by the provision of the wet scrubber of the present invention, the performance of capturing paint particles contained in the exhaust stream from the spray chamber of the paint spray booth is dramatically improved, and energy consumption is reduced. The effect of being improved is obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the principle of trapping particles in an air stream with water when a wet scrubber according to the present invention is used.

FIG. 2 is an enlarged sectional view showing details of a venturi throat part of the wet scrubber of the first embodiment shown in FIG. 5;

FIG. 3 is a partial cross-sectional view showing the internal details of a venturi structure of the wet scrubber of the first embodiment shown in FIG. 5;

FIG. 4 is a plan view of the venturi structure of the wet scrubber of the first embodiment shown in FIG. 5 as viewed from above.

FIG. 5 is a front view showing a wet scrubber according to the first embodiment of the present invention.

FIG. 6 is a plan view of the wet scrubber of the first embodiment shown in FIG. 5 as viewed from above.

FIG. 7 is a schematic view showing a paint spray booth equipped with the wet scrubber of Example 1 shown in FIG.

FIG. 8 is an enlarged view showing the inside of a scrubber chamber of the paint spray booth shown in FIG. 7;

FIG. 9 is an enlarged view showing a bounce means attached to the wet scrubber of the first embodiment shown in FIG. 5;

FIG. 10 is an enlarged view showing a bounce means attached to the wet scrubber according to the second embodiment of the present invention.

FIG. 11 is a photograph of the venturi structure taken from above during operation of the conventional wet scrubber.

FIG. 12 is a photograph of the venturi structure taken from above during operation of the wet scrubber of Example 1.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Venturi-shaped structure part 1a, 1b, 1c structure part 2 Venturi throat part 3 Bounce means 4, 4a, 4b, 4c Inner wall 5 Water group of microdroplets 6 Bounce means (ring of a round tube) 7 Bounce plate 8 Entrance 10 Wet scrubber Reference Signs List 20 paint spray booth 21 air supply chamber 22 spray chamber 23 scrubber chamber 24 exhaust duct 30 flow plate s channel central area f exhaust stream passing through Venturi-shaped structure W water for trapping particles p from entrance of Venturi-shaped structure , Water flowing into it w water flowing down on the inner wall of the venturi-shaped structure

Continued on the front page (72) Inventor Hitoshi Yano 1-9-9 Kakimoto-cho, Toyota-shi, Aichi Prefecture Trinity Industry Co., Ltd. F-term (reference) 4D073 AA01 BB01 BB03 BB05 DC02 DC09 DC14

Claims (6)

[Claims] 1. A venturi-shaped structure through which an airflow is accelerated, and water for trapping particles contained in the airflow is provided on an inner wall of the structure and on the wall thereof. At the venturi throat portion of the Venturi-shaped structure having a reduced diameter, receiving the flowing water, deflecting the flow upward from horizontal and flowing the flowing water through an airflow. A wet scrubber characterized by comprising a rebound means capable of forming a water group of fine droplets in the central area of the flow path by discharging toward the central area of the path. 2. The rebounding means is constituted by a rebounding plate extending upward from the inner wall of the Venturi-shaped structure upward from the inner wall of the Venturi-shaped structure portion over the entire circumference of the Venturi throat portion or at a necessary position. , Claim 1
A wet scrubber as described in. 3. The wet scrubber according to claim 2, wherein an upper surface of the bounce plate is inclined at an angle of 30 ° to 60 ° with respect to a horizontal plane. 4. The rebounding means according to claim 1, wherein the rebounding means is constituted by a rebounding pipe or a rod fixed to the inner wall of the Venturi-shaped structure part over the entire circumference of the Venturi throat part or at a necessary place. A wet scrubber as described in. 5. The method according to claim 4, wherein the bounce tube or the shaft has an outer diameter of 1.5 cm to 15 cm when the venturi throat has an inner diameter of 30 cm to 300 cm. The described wet scrubber. 6. A spray chamber in which an object is spray-coated, and b) a scrubber chamber disposed below the spray chamber and having a flow plate provided with an opening at an upper portion thereof. c) a wet scrubber according to any one of claims 1 to 5, wherein a lower part of the flow plate of the scrubber chamber is provided with an upper part of a venturi-shaped structure adapted to the opening. D) water supply means for supplying water for the capture of paint particles onto said flow plate and flowing onto the inner wall of the venturi-shaped structure of said wet scrubber; and e) exhaust air containing paint particles to be removed. And a discharge mechanism for drawing air from the spray chamber through the wet scrubber.