JP2001025692A - Wet scrubber and coating spray booth equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a catching performance of a coating particle contained in an exhaust flow better as compared with that of the prior arts in a wet scrubber having a venturi type structure part for allowing an exhaust flow to pass therethrough for acceleration, and supplied with water onto an inner wall of the structure part to flow down, and to achieve sufficiently its improvement only by carrying out simple remodeling to the existing wet scrubber, and then to make easy its application to a coating spray booth already brought into use. SOLUTION: A wet scrubber 1 is structured as follows. Preferably sprinkling gutters 10, 10 of which cross sections form V shape (or water guide gutter) are extended to a central area of a channel from an inner wall 8b of the structure part in a venturi throat part 6 or its neighboring part in a venturi type structure part. Then, water in the sprinkling gutters 10 introduced in the central area of the channel from the inner wall 8b, is scattered outside from its side edge, and can be mixed in an exhaust flow f.

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. This typical wet scrubber does not normally have additional components or elements within the venturi-shaped structure in terms of ensuring a smooth flow of airflow, but provides better mixing efficiency with the exhaust flow. In order to increase the height, a method has been proposed in which a water shower hole is provided on the inner wall of the Venturi structure toward the narrowest throat. However, this proposal is not a practically preferable one because clogging of the water shower holes occurs with time due to paint particles or the like in the exhaust stream. No. 5,074,2 U.S. Pat.
Nos. 38 and 4,664,060 propose improvements of this kind of technology. By the way, as the improvement of the wet scrubber provided with the venturi-type structure, the present applicant has
Recently, an eddy current wet scrubber has been proposed.
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. Certainly, the above-mentioned swirl type wet scrubber has been improved in terms of pressure loss, energy consumption, noise, etc., but since it is a relatively large facility, the existing paint which is currently operating is used. When replacing a wet scrubber that has already been installed in the spray booth, it is often difficult to install the wet scrubber due to the internal structure of the scrubber room and the size of the room 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 necessary to improve the performance of capturing paint particles contained in the exhaust stream with higher energy consumption. There was a need for other means and methods to be developed.

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-shaped structure, a water spouting gutter having a concave cross section such as a V-shape or a semi-circular shape is provided on the inner wall of the structure at or near the smallest diameter venturi throat. When the wet scrubber is operated, water flowing down on the inner wall of the venturi-shaped structure is guided to the central area of the air flow along the sprinkler gutter when the wet scrubber is operated. The airflow passing through the central area of the road causes fine droplets or fog from the side edges of the water spray gutter to be scattered outward, and as a result, the mixing of the water and the exhaust flow is further promoted, and the paint particles contained in the exhaust flow Capture performance was found that significantly improved. Further, as another aspect, the present inventors provide a water guide gutter extending from the inner wall of the structure part to the center area of the flow path of the air flow at or near the venturi throat part of the Venturi-shaped structure part and connected thereto. When the water spray gutter is provided in the central region of the air flow path, the same operation and effect as in the above case, that is, the water flowing down on the inner wall of the venturi-type structure portion during the operation of the wet scrubber, The airflow is guided along the gutter to the central area of the flow channel, and the airflow passing through the central area of the flow path scatters outward as small droplets or fog from the side edge of the watering gutter. It has been found that the mixing is promoted, which has a surprising effect that the ability to trap paint particles in the exhaust stream is significantly improved, and 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, and a sprinkler gutter is provided at the thinnest Venturi throat part or a part near the upstream or downstream side of the Venturi-type structure part. The water on the inner wall of the structure extending from the inner wall of the structure to the central area of the flow path of the airflow, and guided to the central area of the flow path, scatters outside the side edge of the sprinkler gutter and mixes with the airflow. The present invention relates to a wet scrubber characterized by having a wet scrubber. In another aspect, the present invention comprises a venturi-shaped structure through which an airflow is accelerated through, and water for trapping particles contained in the airflow is deposited on inner walls of the structure. A wet scrubber which is supplied and flows down, wherein a water guide gutter is provided at a narrowest Venturi throat portion of the Venturi-shaped structure portion or at a portion near an upstream or downstream side thereof so that air flows from an inner wall of the structure portion. A water spout is provided extending to the central area of the passage, and a sprinkler gutter is provided in the central area of the flow path of the air flow so as to be continuous with the water guide gutter, and the structure is guided to the central area of the flow path via the water guide gutter. The present invention relates to a wet scrubber having a structure in which water on an inner wall is scattered outside a side edge of the water spout and mixed with an air flow. In these more preferred aspects of the invention, the watering gutter has a cross section of V
It is a gutter having a cross section of a letter shape, a semi-arc shape, or a shape close to them. In another aspect, the present invention provides: a) a spray chamber for spray-coating an object; b) a flow plate disposed below the spray chamber and having an opening at an upper portion thereof. 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 drawing out through a 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 on the inner wall of the Venturi-shaped structure and flows down, and at and near the smallest diameter Venturi throat part, the flowing water is atomized into droplets by the accelerated air flow,
The mixture is stirred and mixed with the accelerating airflow, and the particles in the airflow are taken into 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 accelerating air flow is continuously performed in the venturi-type structure portion, and the flowing water of the particles in the air flow. Removal 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. About 20cm in width and 15 in length
Wet scrubbers with a venturi throat with a narrow rectangular opening up to about 0 cm are also in practical use. Further, the throat portion of the venturi-shaped structure may be, for example, a circular or elliptical opening having a radius (major axis, minor axis) of about 30 cm to about 80 cm, respectively.

[0008] In one embodiment, the wet scrubber of the present invention is provided at the venturi throat portion having such an opening or a portion near the upstream or downstream thereof.
A sprinkler gutter extends from the inner wall of the venturi-shaped structure to the center of the airflow channel, and in another embodiment, a water guide gutter extends from the inner wall of the Venturi-shaped structure to the center of the airflow channel. And a sprinkling gutter is provided in the central region of the flow path of the air flow, and connected to the water guiding gutter. Therefore, during operation of the wet scrubber, a portion of the water flowing down on the inner wall of the venturi-shaped structure enters the watering gutter and is guided along the gutter to the central region of the air flow, Alternatively, it is configured to penetrate into the water guide gutter, be guided by the gutter, and be guided to the sprinkler gutter in the central region of the air flow channel. In general, since the venturi throat portion is the portion having the smallest diameter, the airflow is accelerated to the highest speed when passing through the throat portion. Moreover, in general, like the flow of Poiseuille, among the flow paths in the Venturi-shaped structure, the velocity of the airflow passing through the peripheral area near the inner wall and the inner wall is the lowest, and the velocity of the passing airflow is lower than that of the inner wall surface. The further away, the greater the velocity of the airflow passing through the central area. Therefore, in the present invention, the water in the sprinkler gutter guided from the inner wall of the venturi-shaped structure portion to the central region of the airflow channel is blown at a higher speed or the highest speed. In other words, in the central area of the airflow channel, the water in the sprinkler gutter does not simply overflow from the side edge of the gutter but flows down, but is pushed by the pressure of the high-speed airflow blown, and the water from the side edge of the gutter. The droplets are scattered outward as fine droplets and can be mixed with the passing airflow. In this case, according to the principles of hydrodynamics, the velocity of the airflow passing near the side edge of the sprinkler will be up to twice as high as the velocity of the airflow hitting the center of the recess of the sprinkler. Therefore, in the present invention, the water that overflows from the side edge of the sprinkler gutter scatters vigorously outward as fine droplets due to contact with a remarkably fast high-speed airflow, and the passing airflow. Can be mixed violently. 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 has an air current flowing on a surface of the inner wall and a peripheral area close thereto. , And gas-liquid mixed. The airflow passing through the venturi-shaped structure is considered to be similar to the flow of Poiseuille, so the velocity of the airflow passing through the peripheral area near the inner wall is compared with the velocity of the airflow passing through the central area of the flow path. Considerably lower. Therefore, in the conventional wet scrubber of this type, since the portion of the low-speed airflow in the passing airflow is mainly mixed with water, the efficiency of gas-liquid mixing is lower. . In other words, from another viewpoint, in a wet scrubber having a conventional structure,
Of the airflow passing through the venturi-shaped structure, the airflow passing through the central region of the flow path hardly comes into contact with the water flowing on the inner wall of the structure, that is, without sufficient gas-liquid mixing being performed. , Through the venturi-shaped structure. Especially in the conventional wet scrubber where the venturi throat part is a wide mouth opening,
There is a greater tendency for the airflow to pass through without mixing with the water on the inner wall. Conventionally, paint spray booths in automobile factories equipped with conventional wet scrubbers have traditionally increased the air suction to the wet scrubber or improved the venturi-type structure to improve the ability to trap particles in the airflow. Methods such as changing the internal shape to a shape that increases the average flow velocity of the entire passing airflow were sometimes used, but the pressure loss significantly increased and the energy required to remove paint particles was increased. This has caused a problem that the consumption amount of the water has increased remarkably. On the other hand, in the wet scrubber of the present invention, at and around the venturi throat, the water flowing down on the inner wall of the structure only comes into contact with the airflow passing through the peripheral area near the inner wall. Instead, a part of the water flows into the sprinkler gutter or the water guide gutter, and in the central area of the air flow channel, the water overflowing from the side edge of the sprinkler gutter comes into contact with the remarkably high-speed air flow and is mixed with gas and liquid. It has a configuration. Therefore, in the wet scrubber of the present invention, in addition to the mixture of the lower-speed airflow portion and the water, the extremely high-speed airflow portion and the water are mixed in the passing airflow. The efficiency of gas-liquid mixing becomes very high. In other words, from another viewpoint, in the wet scrubber of the present invention, by installing the watering gutter, of the airflow passing through the venturi-shaped structure portion, the airflow passes through the peripheral region near the inner wall of the structure portion. In addition to the airflow portion, the airflow portion passing through the central region of the flow channel efficiently comes into contact with water, and is sufficiently mixed with the water that has become microdroplets.
Therefore, even in a wet scrubber in which the venturi throat portion is a wide-mouth opening, the occurrence of a situation in which the air flow passes through the venturi-shaped structure portion without contact with water and without mixing is prevented more effectively. . Therefore, since the wet scrubber of the present invention has a structure capable of sufficiently mixing the entire airflow with water as described above, the performance of capturing particles in the airflow is significantly improved. The inventor has
Actually, in a practical wet scrubber having a venturi-shaped structure, when the velocity of the passing airflow at the venturi throat portion is set to be about 25 to 27 m / s or more, in the conventional wet scrubber without a watering gutter, By providing a water spray trough in the central region of the airflow channel, the wet scrubber has an efficiency of capturing the paint particles in the exhaust flow of about 85-88%. It confirms the fact that it improves to 96-98%. Also noteworthy here is that
In the present invention, as described below, the sprinkling gutter (or the water guiding gutter and the sprinkling gutter) is elongate, for example, less than 5 cm in width and usually 1-2 cm in order to achieve high-efficiency mixing of water and airflow. Since the structural material is sufficient, the amount of increase in pressure loss caused by the provision of these gutters is very low so as not to cause a practical problem. Further, as described above, a conventional wet scrubber in which a water shower device is provided on the inner wall of the Venturi structure portion toward the Venturi throat portion has been proposed. However, this improved wet scrubber merely supplies small droplets of water to the exhaust flow path by spraying water, and the water and the air flow are separated by the atomization of water by contact with a high-speed air flow. It is not a device that can dramatically increase the mixing efficiency of the above. Therefore, even with the improved wet scrubber described above, a remarkable improvement in the ability to capture paint particles contained in the exhaust stream cannot be expected. Besides, in the improved wet scrubber,
New energy is required for water spraying, resulting in increased energy consumption. On the contrary, the wet scrubber of the present invention does not have these drawbacks, and has the advantage that, in addition to the improvement of the ability to capture particles in the airflow, no additional energy is required.

In the wet scrubber of the present invention, a sprinkler gutter is provided in the venturi-type structure alone or in connection with the water guide gutter for atomization of water. As a watering gutter, when placed in the central area of the airflow channel in the venturi-shaped structure, the water in the gutter overflows from the side edge of the gutter, and the overflow water is made into fine droplets by contact with the airflow. The present invention can be applied to any structural material that can achieve the above. Further, as the water guide gutter, any structure material that can guide water on the inner wall of the venturi-shaped structure portion to the central region of the airflow channel can be applied to the present invention. A sprinkler gutter that is used independently without using a water guide gutter also has this function. The sprinkling gutter of the embodiment used alone may be, for example, a gutter member having a structure extending from the inner wall of the venturi-shaped structure to the central region of the airflow channel and having a closed end, and also having an inner wall. A gutter member extending from the portion to the center region of the flow path and further extending to a portion facing the inner wall may be used. Also,
This type of watering gutter is not limited to a straightly extending gutter, and a gutter curved in a curved shape such as an S-shape, a gutter bent in a zigzag shape, an annular gutter, or the like can be applied to the present invention. it can. Also, in the embodiment in which the water guide gutter is provided,
The water guide gutter may be any gutter member having a structure extending from the inner wall of the venturi-shaped structure portion to the central region of the air flow passage and having a tip connected to the sprinkler gutter. In the central area of the flow channel, a gutter member having a structure formed in a ring shape or a curved shape such as an S-shape in connection with the water guide gutter may be used. Further, the watering gutter according to the present invention may be a set of a plurality of gutters arranged substantially in parallel, or may be an integrated gutter in which a gutter member and a gutter member cross each other to form a lattice shape. The size (especially the width dimension) and the number of the watering gutters are determined as appropriate based on the size of the opening at the venturi throat, the flow rate of the passing airflow, and the amount of water supplied to the inner wall of the venturi-shaped structure. Is done.
For example, the width of the sprinkler gutter is usually about 1 cm in width in order to stably supply a desired amount of water to the central region of the air flow channel.
A watering gutter of a few centimeters, preferably a gutter with a width of a few cm, is applied as the watering gutter. In addition, the distance between one watering gutter and the next watering gutter is usually about 5 to 30 cm, more preferably about 10 to about 20 cm, from the viewpoint of achieving efficient gas-liquid mixing. Is set. Also,
In the present invention, basically, any structural material having a concave cross section can be applied to a watering gutter. For example, a gutter member having a U-shaped, U-shaped, semicircular or V-shaped cross section can be applied to the watering gutter of the present invention. However, in the case of a watering gutter having a U-shaped or U-shaped cross-section or a cross-section having a shape similar thereto, the watering gutter has an outer surface extending substantially vertically from a side edge of the gutter.
Some of the water that overflows from the side edges of the gutter scatters as small droplets due to high-speed airflow, while the remaining water remains on the outside of the gutter without being reduced to small droplets. Runs down the surface. That is, a significant amount of the overflow water from the sprinkler gutter is not used for mixing with the airflow. Further, in the case of a watering gutter having a cross section of a semicircular arc shape or a shape close to this, since the watering gutter has an outer surface that extends downward while gently curving inward from the side edge of the gutter, As compared with the sprinkler gutter having a U-shaped cross section, the ratio of water used as a microdroplet for mixing with the high-speed airflow in the overflow water from the sprinkler gutter is increased, The rate of water flowing down the outer surface is reduced. And, in the case of a watering gutter having a V-shaped cross section or a cross-section having a shape similar thereto, the watering gutter has an outer surface that extends sharply inward from the side edge of the gutter, and therefore runs down the outer surface of the gutter. The amount of water that flows downwards is almost small, and among the overflow water from the sprinkler gutters, the highest percentage of water that is used to mix with the airflow as microdroplets in contact with the high-speed airflow is the highest. Become.
Therefore, a more preferable aspect of the present invention is the above wet scrubber, which is provided with a water spout gutter having a V-shaped cross section, a semicircular arc-shaped cross section, or a cross section similar thereto. In a most preferred embodiment, the above-mentioned wet scrubber is provided with a sprinkler gutter having a V-shaped cross section or a cross-section similar thereto.

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.

Example 1 FIG. 4 illustrates the interior of a paint spray booth 20 used to spray coat 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. As shown in FIG. 5 in an enlarged manner, a flow plate 30 is stretched over the scrubber chamber 23, and an opening 31 is formed in the center of the flow plate 30. The wet scrubber 1 of the present embodiment is mounted on the flow plate 30 by fixing the entrance 5 portion to these openings 31. Therefore, the air (including the paint mist) in the spray chamber 22 is sucked by the operation of the exhaust fan mechanism, and is introduced into the wet scrubber 1 as a descending exhaust stream,
Then, it passes through the wet scrubber 1 and exits 19
It is further discharged into the lower space of the scrubber chamber 23. On the other hand, tubs 32, 32 are respectively provided 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. Accordingly, water is supplied to the left and right tubs 32 by operating a pump (not shown). And water is left and right tubs 32, 32
It overflows and flows over the flow plate 30 to form a shallow pool (W in the figure), and then, near the center thereof, gets over the peripheral edge 9 of the entrance 5 of the wet scrubber 1 and flows 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 openings 31 in a row 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 on the openings 31.
Therefore, the wet scrubbers 1... Of the present embodiment are arranged in a line in the paint spray booth 20 in the longitudinal direction. Further, the scrubber chamber 23 is connected to an exhaust duct 24 and communicates with the exhaust fan mechanism via the exhaust duct 24. In the scrubber room 23, there is a wet scrubber 1.
A drain 34 is provided at a bottom portion below the outlet 19, and water containing paint discharged from the wet scrubber 1 falls and collects there. Further, some mist separators 35 are attached to the flow path of the airflow communicating with the exhaust fan mechanism.

Next, details of the wet scrubber 1 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 FIG. 1, the wet scrubber 1 includes a venturi-shaped structure 2, a mixing unit 3 connected to a lower side of the structure 2, and a reduction unit horizontally connected to the side of the mixing unit 3. 4. The venturi-shaped structure portion 2 is composed of a throttle structure portion called a venturi in which the exhaust flow f from the spray chamber 22 is accelerated while passing through it.
As shown in the figure, the upper end has an entrance 5 having a large round hole, and the lower end has a venturi throat portion 6 having the smallest diameter. Entrance 5
Is fixed to the flow plate 30 by being folded outward and locked in the opening 31. As shown in these figures, the venturi-shaped structure portion 2 is divided into an upper portion 2a connected below the entrance 5 and a lower portion 2b connected further down to the throat portion 6. The opening 7a at the boundary between the upper part 2a and the lower part 2b is a circular opening, and the opening 7b in the venturi throat part 6 is a rectangular opening having a length of about 45 cm and a length of about 55 cm. Accordingly, the upper portion 2a has a shape close to the inner surface of the cylinder and has an inner wall 8a configured to decrease as the opening cross-sectional area progresses downward, and the lower portion 2b has a shape close to the inner surface of the square cylinder and has an opening cross-sectional area. It has an inner wall 8b configured to decrease as it goes downward. Accordingly, the venturi-shaped structure 2 is moved by the suction of the exhaust fan mechanism.
Is accelerated as the exhaust stream f from
The velocity of the exhaust flow f is highest when passing through the venturi throat portion 6 having the smallest diameter, while the water W on the flow plate 30 passes over the peripheral edge 9 of the inlet 5 (in FIG. 1, p is the water Is supplied into the venturi-shaped structure 2 and flows down on the inner wall 8a and on the inner wall 8b (FIG. 1).
In the equation, w represents a film of flowing water flowing down on the inner wall 8a and the inner wall 8b of the structure 2. In the vicinity of the venturi throat region 6, the falling water film w is formed into small droplets by spraying the high-speed exhaust gas flow f, and falls into the mixing unit 3. The mixing section 3 is a chamber that forms a pool 11 at the bottom thereof. The pool 11 has a configuration in which water that has fallen into small droplets and falls near the throat portion 6 accumulates. In the mixing section 3, the exhaust flow f passing through the venturi throat portion 6 collides with water accumulated in the pool 11, and gas-liquid mixing is performed. Thereafter, the mixture of the exhaust stream f and the water of the droplets is guided to the speed reduction unit 4 while changing the direction of the flow,
At this time, it passes through the curtain c of water that has fallen from the venturi-shaped structure portion 2. 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 into small droplets of water. In addition,
The mixing section 3 is formed by suspending the adjusting plates 12, 12 so as to face the venturi throat region 6. Adjustment plates 12, 12
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 6. Therefore, the speed of the exhaust flow f toward the pool 11 can be controlled by enlarging or reducing the cross-sectional area of the flow path by tilting the adjusting plates 12 and 12. The reduction section 4 is a cylindrical duct connected to the side of the mixing section 3, and has a structure in which the cross-sectional area of the opening increases toward the outlet 19 from a connection portion with the mixing section 3. . The mixture of the exhaust stream f and the water guided from the mixing section 3 is decelerated while flowing through the reduction section 4, and the exhaust stream f mixed with the droplet water has a sufficiently low velocity. After that, it is discharged from the outlet 19 into the scrubber chamber 23, and
The water that is not sufficiently mixed with the exhaust stream f in the mixing section 3 and the deceleration section 4
The water that has fallen in the inside of the
Spilled from 9 Thus, the exhaust stream f discharged from the outlet 19 of the wet scrubber 1 is one in which the paint particles and the like contained therein have already been removed, but flows around the inside of the scrubber chamber 23 and exhausts. The air is discharged to the outside air through the duct 24. On the other hand, the water flowing out of the outlet 19 of the wet scrubber 1, which contains the paint particles and the like in the exhaust stream f, falls into the drain 34 (FIGS. 4 and 5) and is collected thereafter.

In this embodiment, FIGS. 1 and 2
Then, as shown in detail in FIG.
In FIG. 6, two watering gutters 10 and 10 extend from the inner wall 8b on one side of the venturi-shaped structure portion 2 to the inner wall 8b on the opposite side through the airflow channel central area 15 (FIG. 6). . Each of the two watering gutters 10, 10 is a gutter member having a V-shaped cross section and a width of about 2.5 cm,
They are juxtaposed in parallel with an interval of cm. Therefore, during operation of the wet scrubber, a part of the water w flowing down on the inner wall 8b of the venturi-shaped structure 2 is
10 (in FIG. 3, q represents the flow of water flowing into the gutter 10), and is guided along the gutters 10, 10 to the central area of the flow path of the airflow, and Are overflowed from the left and right side edges 13, 13. Generally, since the venturi throat portion 6 is a portion having the smallest diameter, the exhaust flow f is accelerated to the highest speed when passing therethrough. In general, as shown in FIG. 6, the velocity of the air flow is not uniform in the flow path in the venturi-shaped structure portion 2 and has a parabolic velocity distribution. va
Is much faster than the velocity vb of the airflow passing through the peripheral area 15 near the inner wall. Therefore, a higher or highest speed airflow is blown to the water in the watering gutters 10 and 10 guided from the inner wall 8b of the venturi-shaped structure portion 2 to the channel center region 14. Therefore, as shown in FIG. 7, the water in the sprinkler gutter 10 is pushed by the pressure of the high-speed airflow blown, and becomes small droplets outward from the left and right side edges 13, 13 of the gutter. It can be scattered and mixed with the passing airflow. In this case, the velocity vc of the air flow passing in the vicinity of the side edge 13 of the watering gutter 10 (FIG. 8A)
The velocity of the air flow f hitting the center of the U-shaped recess is approximately 1.
Up to 5 times faster. Therefore, the side edge 1 of the watering gutter 10
The water overflowing out of the holes 3 and 13 can be vigorously dispersed as fine droplets by virtue of contact with the exhaust stream f at a remarkably high velocity, and can be mixed violently with the passing exhaust stream f. Therefore, in the present embodiment, the water flowing down on the inner wall 8b of the venturi-shaped structure portion 2 at and near the venturi throat portion 6 comes into contact with the exhaust flow f passing through the peripheral area 15 near the inner wall 8b. Not only that, but some of them
As it flows into 10 and overflows the side edge 13 of the gutter 10 in the central area 14 of the flow path, the overflow water comes into contact with the remarkably high velocity exhaust stream f and becomes small droplets and is agitated and mixed. That is, in the present wet scrubber, the lower-speed airflow portion of the exhaust flow f passing through the inner wall 8b
The portion of the airflow which is mixed with the above flowing water and has a significantly higher velocity is mixed with the water overflowing from the sprinkler gutter 10, so that the efficiency of gas-liquid mixing is very high. Further, in the wet scrubber 1, the high-speed airflow passing through the flow path central area 14 is also mixed with the water in the form of fine droplets. The occurrence of the situation of passing through the venturi-shaped structure portion 2 without being mixed is more effectively prevented. As described above, in the wet scrubber 1 of the present example, the performance of capturing the paint particles in the exhaust stream f is significantly improved. Moreover, the effect of improving the trapping performance is due to the Venturi-type structure 2
For existing wet scrubbers equipped with
This is advantageous because it can be obtained only with the equipment. In the above embodiment, the sprinkler gutter 10 is a gutter member having a V-shaped cross section. However, as shown in FIG. 8B, the sprinkler gutter has a semicircular cross section. The gutter 16 and the watering gutter 17 having a U-shaped cross section as shown in FIG. 8C can be similarly applied. However, the proportion of overflow water that is used as a microdroplet for mixing with the exhaust stream f differs depending on the cross-sectional shape of the watering gutter. In the case of the sprinkler gutter 10 having a V-shaped cross section as shown in FIG. 8A, the outer surface 18 has a structure that extends sharply inward from the side edge 13 of the gutter. The amount of water flowing down along the outer surface 18 of the water is almost small, and the percentage of the water in the form of fine droplets used for mixing with the high-speed exhaust flow f among the overflow water from the water spraying gutter 10 is as follows: Will be the highest. However, in a sprinkler gutter 16 having a semicircular cross section as shown in FIG. 8 (b), the outer surface 18 has a side edge 13 of the gutter.
Due to the structure that extends downward while gently curving inward, a certain amount of water out of the overflow water from the sprinkler gutter 16 flows down along the outer surface 18 of the gutter and falls down to form fine droplets. Thus, the proportion of water available for mixing with the exhaust stream f is reduced as compared to the watering trough 10 having a V-shaped cross section. Further, in the case of the watering gutter 17 having a U-shaped cross section as shown in FIG.
Has a structure that extends substantially vertically downward from the side edge 13 of the gutter 17, so that a large part of the water that overflows from the side edge 13 of the gutter 17 is not changed into small droplets, and the outer surface of the gutter 17 is kept as it is. 18
, And therefore, the proportion of water used in the mixing with the exhaust stream f in the form of fine droplets becomes the smallest.

As described above, in the wet scrubber 1 of the present 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 significantly improved as compared with the conventional case. In addition, sufficient modifications can be achieved by simply modifying existing wet scrubbers with sprinkling gutters, and therefore, it is very easy to apply to existing paint spray booths. It has the advantage that. This improvement effect is also confirmed from the results of comparison experiments shown below for the case of the existing wet scrubber with the watering gutter and the conventional example without the watering gutter. .

Embodiment 2 This embodiment is different from the paint spray booth of Embodiment 1 in that the wet scrubber 1 is used instead of the wet scrubber 1 shown in FIGS.
This is an example in which the wet scrubber 41 shown in FIG.
The configuration of the wet scrubber 41 of the second embodiment is the same as that of the first embodiment unless otherwise specified below. As shown in FIG. 9, the wet scrubber 41 includes a venturi-shaped structure 2a through which the exhaust flow f from the spray chamber 22 is accelerated, and a mixing unit 3 connected to the lower side of the structure 2a. And a speed reduction unit 4 horizontally connected to the side of the mixing unit 3. In the venturi-shaped structure portion 2a of this example, the venturi throat portion 6a has a circular opening. By suction of the exhaust fan mechanism, the spray chamber 22
Is accelerated as it passes through the venturi-shaped structure 2a, while the water W on the flow plate 30 is supplied into the structure 2a over the peripheral edge 9 of the inlet 5 and flows on the inner wall 8 In FIG. 10, w represents a film of water flowing down on the inner wall 8. In the vicinity of the throat portion 6a, the flowing water film w is formed into small droplets by spraying a high-speed exhaust gas flow f, and mixed. It is configured to drop to the section 3.
In the present embodiment, as shown in detail in FIGS. 10 and 11, at the venturi throat part 6a, four water guide gutters 42 are respectively arranged at the center of the flow path of the airflow from the inner wall 8 of the venturi-shaped structure 2a. A ring-shaped sprinkler gutter 43 is provided in the central region of the flow path of the air flow so as to extend to the four water guide gutters 42. Water guide gutter 42
Are arranged symmetrically in such a manner that they are slightly lowered from the inner wall 8 toward the center of the flow path from the four sides. The water guide gutter 42 has a V-shaped cross section, and the sprinkler gutter 43 has a U-shaped cross section, both of which are gutter members having a width of about 2.5 cm. Therefore, during the operation of the wet scrubber 41, a part of the water w flowing down on the inner wall 8 of the venturi-shaped structure portion 2a enters the water guide gutter 42, and then flows down the gutter 42 to reduce the airflow. It is guided to the central area of the flow path, flows into the sprinkler gutter 43, and then overflows outward and inward over the entire circumference from the annular side edge 13 of the gutter 43. Below the gutters 42 and 43, an adjusting cylinder 44 having a wide-mouthed cylinder and having a diameter reduced toward the bottom is fixed, and inside the gutter 42, 43, a range indicated by an arrow t in the figure is fixed. An adjusting body 45 having a flared shape that can be moved up and down is provided so that its head is accommodated in the ring-shaped watering gutter 43. The adjustment cylinder 44 is a member having a round bottom 46 with an opening, and a rib 47 formed on the outer peripheral surface thereof is locked on a support flange 48 on the inner wall 8 of the structural portion 2a, thereby forming a venturi-shaped structure. It is arranged in the section 2a. Therefore, the cross-sectional area of the flow path in the round bottom 46 can be freely changed by raising and lowering the adjusting body 45, and therefore, the speed of the exhaust flow f toward the mixing unit 3 can be controlled by increasing or decreasing the cross-sectional area. It has a configuration.

Thus, in the present embodiment, near the venturi throat portion 6a, the water flowing down on the inner wall 8 of the venturi-shaped structure portion 2a comes into contact with the exhaust flow f passing through the peripheral area near the inner wall 8. In addition, a portion of the water flows into the water guide gutter 42, flows down the gutter 42, is guided to the central area of the flow path, and flows into the ring-shaped watering gutter 43, When it overflows from the side edge 13 of the gutter 43, the overflow water comes into contact with the exhaust flow f at a very high speed and becomes violent gas-liquid mixing as fine droplets. That is, in the wet scrubber 41, of the passing exhaust gas flow f, the lower speed airflow portion is mixed with the flowing water on the inner wall 8, and the significantly higher speed airflow portion is caused by the overflow water from the sprinkler gutter 43. Mixing, and therefore the efficiency of gas-liquid mixing is very high.
In the wet scrubber 41, the high-speed airflow passing through the central region of the flow path is also mixed with the water in the form of fine droplets. The occurrence of the situation of passing through the venturi-shaped structure portion 2a as it is is more effectively prevented. As described above, the wet scrubber 41 of the present example also has a remarkably improved performance of capturing the paint particles in the exhaust flow f as compared with the related art. In addition, the effect of improving the trapping performance can be obtained only by installing the water guide gutters 42 and the sprinkler gutters 43 with respect to the existing wet scrubber having the Venturi-type structure, and the existing paint spray booth can be obtained. It is very advantageous because it is easy to apply.

[0018]

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 a schematic diagram illustrating a wet scrubber according to a first embodiment of the present invention.

FIG. 2 is a plan view of the wet scrubber of the first embodiment shown in FIG. 1 as viewed from above.

FIG. 3 is an enlarged perspective view of a venturi throat portion of the wet scrubber of the first embodiment shown in FIG. 1 as viewed obliquely from above.

FIG. 4 is a schematic view showing a paint spray booth equipped with the wet scrubber of the first embodiment shown in FIG. 1;

FIG. 5 is an enlarged view showing the inside of a scrubber chamber of the paint spray booth shown in FIG. 4;

FIG. 6 is a diagram showing a state of passage of airflow and flow of water in a venturi-shaped structure in the wet scrubber of the first embodiment shown in FIG. 1;

FIG. 7 is a view showing a state of gas-liquid mixing in the vicinity of a venturi throat part in the wet scrubber of the first embodiment shown in FIGS. 1 to 3;

FIGS. 8 (a) to 8 (c) are views showing how water is formed into fine droplets and scattered outside from a watering gutter in the wet scrubber of the first embodiment. ) Indicates a sprinkler having a V-shaped cross section, FIG. 8B indicates a sprinkler having a semicircular cross-section, and FIG. Each shows a case of a watering gutter having a U-shaped cross section.

FIG. 9 is a schematic view showing a wet scrubber according to a second embodiment of the present invention.

FIG. 10 is an enlarged view showing a venturi-shaped structure of the wet scrubber according to the second embodiment shown in FIG. 9;

FIG. 11 is an enlarged view of the venturi-type structure shown in FIG. 10 from above in the wet scrubber of the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Wet scrubber 2, 2a Venturi-shaped structure part 3 Mixing part 5 Entrance 6, 6a Venturi throat part 7a, 7b Opening 8, 8a, 8b Inner wall 10 Sprinkler gutter 13 Side edge 14 Channel center area 15 Channel peripheral area 17 Sprinkler gutter Reference Signs List 18 water spray gutter 20 paint spray booth 21 air supply room 22 spray chamber 23 scrubber room 24 exhaust duct 30 flow plate 41 wet scrubber 42 water guide gutter 43 water spray gutter f Exhaust flow passing through Venturi structure W Water for particle capture p Flow of water flowing into the inlet of the venturi-shaped structure from the inlet w Water flowing down on the inner wall of the venturi-shaped structure q Flow of water entering the sprinkler gutter from the inner wall of the Venturi-shaped structure va Exhaust flow velocity in the central area vb Exhaust flow velocity in the flow path peripheral area vc Exhaust when passing through the side edge of the watering gutter Airflow velocity

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Hitoshi Yano 1-9-9 Kakimotocho, Toyota City, Aichi Prefecture Trinity Industry Co., Ltd. F-term (reference) 4D073 AA01 BB03 DC02 DC12 4F042 AA09 CC01 CC14 CC21

Claims (5)

[Claims] 1. A wet vent, comprising a venturi-shaped structure through which an air flow is accelerated, wherein water for trapping particles contained in the air flow is supplied onto an inner wall of the structure and flows down. A scrubber, wherein a water spray gutter extends from the inner wall of the structure to the center area of the airflow channel at the narrowest Venturi throat part or near the upstream or downstream side of the Venturi-type structure part. And a structure in which water on the inner wall of the structure guided to the center area of the flow passage is scattered outside the side edge of the water spouting gutter and can be mixed with an airflow, Scrubber. 2. The wet scrubber according to claim 1, wherein the water spouting gutter is a gutter having a V-shaped cross section, a semicircular arc-shaped cross section, or a cross section having a shape similar thereto. 3. A wet vent, comprising a venturi-shaped structure through which an air flow is accelerated, and wherein water for trapping particles contained in the air flow is supplied onto an inner wall of the structure and flows down. A scrubber, wherein a water guide gutter extends from the inner wall of the structure to the central region of the airflow channel at the thinnest Venturi throat part or the upstream or downstream vicinity thereof of the Venturi-shaped structure part. And a sprinkler gutter is provided in the center area of the air flow passage so as to be continuous with the water guide gutter, and the water on the inner wall of the structure guided to the center gutter through the water guide gutter is provided with: A wet scrubber having a structure which can be scattered outside of a side edge of the sprinkler gutter and mixed with an air flow. 4. The wet scrubber according to claim 3, wherein the water spouting gutter is a gutter having a V-shaped cross section, a semicircular arc-shaped cross section, or a cross section having a shape similar thereto. A) a spray chamber in which the object is spray-coated; and b) a scrubber chamber disposed below the spray chamber and having a flow plate having an opening formed thereon. c) a wet scrubber according to any one of claims 1 to 4, wherein the lower part of the flow plate of the scrubber chamber is equipped with an upper part of a venturi-shaped structure to fit 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; and e) the spray containing paint particles to be removed. A paint spray booth comprising: an exhaust mechanism that draws exhaust air from a chamber through the wet scrubber.