JP2000237654A - Vortex flow wet scrubber and coating spray booth equipped therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the formation of a vortex flow in a perfect state by forming an inner space wherein a flow path allowing passage of a mixture of gas and liquid restrictively in a helical vortex shape is formed, and an inner wall surface along which the liquid runs restrictively in a substantially helical shape, together with a vortex flow chamber and a vortical body. SOLUTION: The vortex flow chamber 4 and the vortical body 5 are arranged crossing each other and sharing a part of each other's internal space. Consequently, in the inner spaces of these structures, a flow path (p) for allowing passage of a mixture of gas and water to flow restrictively in a helical vortex shape is formed. In addition, the inner wall surface of the vortex flow chamber 4 and the inner wall surface of the vortical body 5 form a flow path (p) of a substantially helical vortex shape cooperatively in such a manner that the inner wall surfaces of both vortex flow chamber 4 and vortical body 5 encircle the flow path (p). Thus the water structurally flows down the surfaces restrictively in the substantially helical shape. A mixture of gas and water spreads over from the vortex flow chamber 4 to the vortical body 5, passing, in the helical vortex shape, through their inner spaces in the (p) direction, so that a vortex flow of a substantially perfect shape is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet scrubber for trapping and removing liquid or solid particles contained in an airflow, and more particularly to a swirl type wet scrubber, that is, an accelerated airflow and a liquid for trapping particles. And colliding and mixing
Next, the present invention relates to a wet scrubber in which the particles are contained in a gas stream and removed by forming a swirl by orbiting the particles. The present invention also relates to a paint spray booth equipped with the above wet scrubber of the present invention and capable of capturing and removing paint particles contained in a flow of air discharged from a spray chamber.

[0002]

2. Description of the Related Art Typically, painting of various mass-produced products, such as automobile bodies and automobile parts, is performed in a paint spray booth, in which the object to be coated is coated with a paint using a spray coating facility. Sprayed. The paint that has not adhered to the workpiece floats in the air as a paint mist. In order to create a high quality painted finish and maintain a safe and healthy working environment, fresh air is continuously supplied into the paint spray booth while simultaneously removing paint mist generated from the work area Is needed. To achieve this object, an exhaust fan mechanism has conventionally been used. At this time, the paint particles contained in the exhaust air must be captured before the airflow goes to the atmosphere in order to avoid environmental pollution. There are two known methods for separating paint mist from the exhaust stream. i) a dry process in which the contaminated airflow is passed through a dry filter or sieve and the paint particles contained therein are adsorbed or trapped by a filter or equivalent, and ii) the contaminated airflow is transferred to a liquid. For example, there is a wet method in which water is mixed with, for example, contact with water, whereby the paint particles contained therein are captured and removed by a liquid. And in a paint spray booth that paints cars,
Usually, a wet method is employed. Various types of conventional wet methods are known, and the following methods and means are typically used. 1. A method of utilizing the gravity difference between an airflow and a liquid such as water to pass the airflow through a liquid bulk to capture paint particles contained in the airflow. 2. A method in which a liquid such as water is caused to flow downward, and an airflow is passed through a liquid film formed thereby, whereby paint particles contained in the airflow are captured in the film. 3. Spray a liquid such as water to create a large group of liquid drops, and pass the contaminated air stream through this liquid mist,
There, a method in which droplets of liquid contact and trap the paint particles to be removed. 4. A method of passing airflow and liquid, for example, water, through a throttle called a venturi. The stirring flow of high velocity air in the Venturi causes atomization of the liquid into droplets. The resulting droplets capture and coalesce the overlaid paint particles. 5. A method wherein a liquid, such as water, is allowed to flow down onto a plate or similar member and an air stream is blown against the plate or the air stream is impinged on a pool of liquid, such as water. The paint particles are contained in a stream of air having greater momentum and are trapped in the liquid due to the collision of the liquid with the stream.

[0003] Typically, the exhaust air stream from a paint spray booth consists of an air stream containing paint mist containing paint particles of various diameters. The diameter of these paint particles is several hundred μ
m to less than 1 μm. In a typical paint mist, there are more fine paint particles than coarse paint particles. In a conventional wet scrubber used in a paint spray booth of an automobile assembly plant, conventionally, the frequency and speed at which the exhaust air stream flowing from the spray chamber collides with the water stream for trapping particles is increased, so that the particles are trapped. Attempts have been made to improve removal efficiency. In this connection, U.S. Patent Nos. 5,074,238 and 5,044
0,482, 4,700,615, 4,664,060, 4,220,
No. 078 and the like disclose various proposals. U.S. Pat. No. 5,074,238 discloses a scrubber with a venturi opening through which exhaust airflow and water passes and a curved baffle where air and water mix. U.S. Pat. No. 5,040,482 discloses a scrubber with two tanks for supplying a surface of water along an inclined surface and a baffle for mixing the water with the paint-laden air. U.S. Pat.No. 4,700,615 discloses a scrubber in which several pools are arranged hierarchically, with water flowing sequentially through the pools, and where the exhaust airflow is made to pass through formed water curtains. are doing. U.S. Pat. No. 4,664,060 discloses a scrubber in which tension is provided in a rectangular venturi to increase airflow and water mixing, and baffles are disposed below the venturi throat. Also, U.S. Pat. No. 4,220,078 discloses that a V-shaped collision member has
Disclosed is a scrubber positioned in the paint flow path and provided with a shroud around the impingement for more removal.

Attempts to remove paint particles more efficiently include:
It has been found that it tends to cause an increase in processing noise. Also, the need to increase the capacity of exhaust fans or the like tends to increase equipment costs as well as energy consumption. Therefore, there is a need for a device that not only increases efficiency but also reduces noise and energy consumption as much as possible. Reduction of noise is also desired from the viewpoint of improving the working environment of workers. U.S. Pat. No. 5,100,442 discloses a scrubber in which exhaust air and water streams are directed to a venturi section. They are then directed to a throttle that limits the noise barrier that prevents noise caused by turbulent mixing to pass upstream. U.S. Pat. No. 5,020,470 discloses a scrubber having an extended exhaust pipe through which exhaust air and water flow. Particles are removed by the effect of the collision of the airflow with the collision pool. Near the top of the discharge pipe,
Little or no water dispersion or atomization occurs and noise is reduced. U.S. Pat. No. 4,515,073 discloses a scrubber having a tortuous path through which air passes several times through a spray of removal fluid. Sound absorbers are provided in the baffles to reduce the impact sound. U.S. Pat. No. 4,350,506 discloses a scrubber having a bell-shaped venturi with an extended middle portion, wherein a sound absorbing material is provided therein. U.S. Pat. No. 4,345,921 discloses a scrubber in which a pair of guide plates are provided in a venturi to create a noise attenuation zone above the throat. The impact plate is located below the venturi throat and may include a water film or puddle. In certain prior art scrubbers, a portion of the effluent stream can pass through the outside of the scrubber with little or no mixing with water, and therefore it still contains paint particles in the effluent stream. It was a good thing. The splashing of water in the pool causes the contaminated water droplets to be discharged to the outside air together with the exhaust air via the exhaust fan. For the purpose of increasing the removal rate of paint particles from paint mist, a device for redirecting the exhaust air flow has been proposed, for example, in U.S. Pat. No. 4,704,952 for air. This patent discloses a scrubber having a structure in which the combined air and water of the paint flow downward through the scrubber and mix together. The outer wall of the scrubber is designed to divert air suddenly upward and then laterally reverse. Air passes through the baffles and is released to the atmosphere.

[0005]

Although the prior art discloses many wet scrubbers, there is still room for improvement. For example, in some conventional wet scrubbers, corners and corners, uneven surfaces and the like are present in the passages through which the exhaust air flows and where the exhaust air flow mixes with water. I do. This results in unnecessary pressure loss, energy waste,
And increase noise. In addition, some conventional wet scrubbers still have a low efficiency in trapping fine paint particles in water and present the problem that some paint mist can be released to the atmosphere. I was In addition, the situation where a large amount of water droplets on which the paint particles are superimposed is directly discharged to the atmosphere via the exhaust fan device has not been sufficiently addressed. Therefore, the present inventors have found that in a wet scrubber, pressure loss can be minimized, energy consumption can be reduced and noise levels can be reduced, and moreover, the efficiency and performance of removing particles contained in the airflow can be improved. R & D was started with the task of further improvement. The present inventor has found that, using hydrodynamics or the like, any structure of the wet scrubber can minimize the pressure loss generated during operation and keep the efficiency of capturing particles in the airflow at a high level. Consider etc.,
And now, based on simulation tests using computer fluid dynamics numerical analysis and several on-site demonstration tests, wet scrubbers with the following structural features,
It has been found that the above object can be sufficiently achieved. The newly-developed wet scrubber accelerates the airflow containing particles through the accelerating cone,
Liquid (usually water) for trapping particles in the gas stream is supplied on the inner peripheral wall of the accelerating cone and flows down, and in the mixing chamber below the accelerating cone, the gas stream and the accelerating gas passing through the accelerating cone are accelerated. The liquid that has flowed down from the cone is impact-mixed and then circulated in a vortex chamber to form a vortex, thereby capturing particles contained in the gas stream into the liquid, and then circulating them through the vortex. ,
It is a so-called vortex-type wet scrubber that discharges after decelerating. More specifically, the above-mentioned swirl type wet scrubber is a cone in which an airflow passes therethrough and is accelerated, and an inlet at an upper end, an outlet at a lower end, and a cross-sectional area are larger than those of the inlet. An accelerating cone surrounding the passage that contracts toward the outlet and having an inner peripheral wall through which water for particle capture can flow from the inlet periphery to the outlet periphery;
A mixing chamber disposed below and in communication with the outlet of the acceleration cone for colliding and mixing an airflow passing through the acceleration cone with water flowing down from the periphery of the acceleration cone; A substantially cylindrical chamber, which is connected to the left and right sides of the mixing chamber in communication with each other and circulates a mixture of airflow and water to form a vortex, wherein the mixture of airflow and water is After orbiting, after decelerating the mixture of airflow and water, a pair of left and right vortex chambers having inner wall surfaces through which water flows over the surface, and each of the vortex chambers being connected in communication with each other. A spiral body discharged from the expanded outlet, comprising a pair of left and right spiral bodies having an inner wall surface continuous with the inner wall surface of the swirl chamber. In this wet scrubber, a pair of left and right vortex chambers and a pair of left and right vortex bodies are symmetrically arranged around an acceleration cone (mixing chamber). The swirl chamber and the spiral body are provided in parallel on the left and right sides, respectively. That is, the substantially cylindrical inner wall surface of the vortex chamber and the inner wall surface of the spiral body are formed independently and adjacent to each other, and have a structure in which they are continuously flush.

[0006] In order to reliably form a vortex inside the vortex-type wet scrubber during operation, such a vortex-type wet scrubber is required.
It is appropriate that an air flow having a flow rate somewhat higher than the reference flow rate determined by the internal volume is allowed to flow through the wet scrubber. By the way, in a paint spray booth for painting an automobile body where a wet scrubber is installed, a large amount of discharged airflow is usually sprayed in the longitudinal direction of the booth in order to cope with the mode and conditions such as coating. It is divided into an area (zone) that needs to be sucked from the chamber into the scrubber chamber, and an area (zone) that only needs to suck a small amount of discharged airflow from the spray chamber into the scrubber chamber, for example. Also, depending on the mode and conditions of painting, etc., in the same area in the paint spray booth,
By switching between a large flow discharge air flow and a small flow discharge air flow,
There may also be zones that need to be able to be drawn into the scrubber chamber from the spray chamber. In order to cope with the magnitude of the flow rate of the exhaust airflow in the paint spray booth, the inventor has provided the above-mentioned vortex chamber and a spiral body symmetrically in a left and right pair in an area where a large flow rate of the exhaust airflow is sucked. A swirl-type wet scrubber with a so-called one-lung structure, in which a swirl chamber and a spiral body are provided only on one of the left and right sides, is applied to the area where the small amount of exhaust air is sucked. Intended to apply. In particular, the present inventor has unified the dimensional standard of each component of the wet scrubber, and has a structure in which the left and right units including the swirl chamber and the spiral body are easily attached to and detached from the mixing chamber. It was planned to design a mold wet scrubber. The swirl-type wet scrubber having such a structure can easily handle a case where a large flow of air is sucked or a case where a small flow of air is sucked by simply attaching and detaching the unit, that is, replacing the unit. The present invention has a great advantage that the manufacturing cost of the swirl type wet scrubber can be reduced as a whole.

Therefore, the present inventor has proposed the above-mentioned one-lung structure,
That is, a vortex-type wet scrubber in which a vortex chamber and a unit of a vortex body are provided only on one of the right and left sides is prototyped, and its wet scrubber performance is examined by a test. However, the prototyped swirl-type wet scrubber having a swirl chamber and a swirl unit on only one side has an unexpectedly poor ability to trap particles contained in the airflow, and has an expected value. Less than about 10% to about 15% of the collection efficiency. The present inventor continued his research to elucidate the cause.As a result, he removed the unit on one side from the vortex-type wet scrubber structure in which the vortex chamber and the unit of the spiral body were provided symmetrically one by one on the left and right. In the eddy current type wet scrubber having the above configuration, it was found that the eddy current was not reliably formed in a substantially perfect form inside the wet scrubber during operation. That is, in the vortex-type wet scrubber of this configuration, during operation, water does not sufficiently flow on the inner wall surface of the unit, but passes through the wet scrubber as an imperfect form vortex, It has the disadvantage that the scrubber performance of trapping particles in the airflow is released, and therefore the scrubber performance is deteriorated as compared with the swirl type wet scrubber in which the swirl chamber and the swirl body are provided symmetrically one by one. Was.
Further, in the vortex-type wet scrubber having the above-described configuration, the vortex chamber and the spiral body are arranged in parallel, and their inner wall surfaces are independently provided adjacent to each other. Does not flow over the entire inner wall surface of the spiral body and the inner wall surface of the spiral body, and there is a portion on the inner wall surface where a sufficient water film is not formed, and thus the ability to remove particles in the air flow (scrubber performance) In addition, paint particles and the like in the air stream are likely to deposit and accumulate in portions where the thickness of the water film is not sufficient, and the inside of the wet scrubber becomes dirty after a short period of use. In short, in the swirl type wet scrubber newly constructed by the present inventor and having a structure of the swirl chamber and the swirl body on only one side, an incomplete form of swirl is formed, and particles in the airflow are formed. It was found that the trapping performance was poor, and that the inner wall surface was not sufficiently formed with a water film as a whole, and that it was easily contaminated due to the accumulation of particles and the deposition of paint particles.

The present invention is directed to a newly developed vortex-type wet scrubber having a vortex chamber and a vortex unit provided only on one side to solve the above-mentioned disadvantages. The aim is to ensure that a perfect form of vortex is formed, while at the same time a film of liquid for particle capture can be formed over the entire inner wall surface of the unit,
The efficiency of trapping particles in the airflow has been improved, achieving the expected scrubber performance, and reducing the generation of dirt due to the deposition of particles inside the wet scrubber, thus cleaning and maintaining the inside of the slab. To provide a swirl-type wet scrubber which makes the process easier. The scrubber performance described above includes, in addition to improved removal of particles in the airflow, more preferably the ability to significantly reduce energy consumption and noise by minimizing pressure drop. Another object of the present invention is a wet scrubber having the above-mentioned excellent performance, which is advantageously applied to an area of a paint spray booth used for painting an automobile body or the like, in which a smaller amount of exhaust air is sucked. It is an object of the present invention to provide a swirl-type wet scrubber that can be used. In another aspect, it is an object of the present invention to provide a paint spray booth with the improved vortex wet scrubber described above. The other objects of the present invention can be easily understood from the following description or based on matters obvious from the description.

[0009]

SUMMARY OF THE INVENTION The present invention more particularly relates to a wet scrubber for removing particles contained therein from an air stream, the cone having an air stream passing therethrough and being accelerated. And an inner peripheral wall surrounding a passage whose cross-sectional area is reduced from the inlet to the outlet, and a liquid for trapping particles in an air flow can flow down from the peripheral edge of the inlet to the peripheral edge of the outlet. An accelerating cone having an air flow passing through the accelerating cone and a trapped air flowing through the accelerating cone from a periphery of the accelerating cone, the accelerating cone having an accelerating cone having an accelerating cone. A mixing chamber for impinging and mixing a liquid for forming a swirl by circulating a mixture of airflow and liquid to form a vortex, the chamber being connected to the side of the mixing chamber in communication therewith. ,
As the mixture of airflow and liquid circulates, a vortex chamber having an inner wall surface through which the liquid flows over the surface, and a deceleration of the mixture of airflow and liquid connected in communication with the vortex chamber. And a spiral body having an inner wall surface continuous with the inner wall surface of the swirl chamber, the spiral body being discharged from the expanded discharge port, and the swirl chamber and the spiral body intersect with each other. The internal space is provided so as to partially share each other, so that the internal space forms a flow path through which the mixture of the gas stream and the liquid is restricted in a spiral shape and flows, and the vortex chamber and A swirl-type wet scrubber, characterized in that the swirl bodies together form an inner wall surface through which the liquid for trapping is substantially spirally confined and flows. About. The present invention typically uses a wet scrubber, i.e. water, as a liquid for trapping particles and a paint mist installed in a paint spray booth for painting car bodies and car parts in car assembly plants. The swirl-type wet scrubber for removing paint particles contained therein from an exhaust stream containing the same. According to another aspect of the present invention, there is provided a) a spray chamber in which the object is spray-coated, and b) a flow plate which is located below the spray chamber and has an opening. C) a swirl-type wet scrubber as described above, which is equipped with an accelerating cone in the flow plate of the scrubber chamber to fit the opening of the flow plate; and d) water for trapping paint particles. Water on the flow plate and flowing onto the inner circumferential wall of the accelerating cone of the wet scrubber; ande) passing the exhaust air from the spray chamber containing the paint particles to be removed through the wet scrubber. The present invention relates to a paint spray booth comprising an exhaust mechanism for drawing out.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The swirl type wet scrubber of the present invention comprises an accelerating cone, a mixing chamber, a swirl chamber and a swirl body, and is characterized by the arrangement of the swirl chamber and the swirl body and their internal space structure. It has. The accelerating cone is a cone through which the air flow is accelerated by passing through it, and has an inlet at the upper end, an outlet at the lower end, and an inner peripheral wall surrounding the passage whose opening cross-sectional area decreases from the inlet to the outlet. And an inner peripheral wall through which a liquid for trapping particles in an air flow can flow from an inlet periphery to an outlet periphery. Therefore, the combined airflow of particles,
For example, an exhaust stream containing paint mist is accelerated as it passes through a passage in the acceleration cone. On the other hand, the liquid for trapping particles is supplied to the inner peripheral wall from the peripheral edge of the inlet of the acceleration cone, and flows down the inner peripheral wall. Then, the airflow that has passed through the acceleration cone and the liquid that has flowed down on the inner peripheral wall of the acceleration cone are discharged from the cone outlet and guided into the mixing chamber below the acceleration cone. Thus, in order to minimize the pressure loss of the airflow at this stage, the accelerating cone is more preferably an inner peripheral wall having no corner portion over one round, and the speed of the airflow discharged from the outlet of the cone is set at the outlet. An inner peripheral wall having a multidimensional curved surface that is substantially uniform over the entire cross section is provided. The multidimensional curved surface is automatically determined by computer calculation by hydrodynamic numerical analysis based on each value of the cross-sectional area of the entrance of the acceleration cone, the cross-sectional area of the exit, and the height of the acceleration cone (the distance between the entrance and the exit). Is done. Generally, the curved surface becomes a curved surface close to a parabolic curved surface. The mixing chamber is a chamber disposed below and in communication with the outlet of the accelerating cone, with a pool surface for collision directly below the outlet of the accelerating cone. Therefore, in the internal space of the mixing chamber, the airflow that has been vigorously discharged below the outlet through the accelerating cone collides with the liquid for trapping that has flowed down to the pool surface from the periphery of the outlet and is mixed. . In order to more efficiently mix and collide the liquid with the gas flow in accordance with the air flow of the gas flow, more preferably, an adjusting means capable of freely adjusting the passage speed of the gas flow is provided near the outlet of the acceleration cone. The adjusting means comprises, for example, a damper capable of freely expanding and reducing the outlet cross-sectional area of the acceleration cone. The vortex chamber is a substantially cylindrical chamber capable of forming a vortex by circling the mixture of the gas flow and the liquid. The chamber is connected to, and in communication with, a side of the mixing chamber and has an inner wall surface in which the liquid flows over its surface as the gas and liquid mixture circulates. This inner wall surface preferably comprises a cylindrical peripheral inner wall surface that is continuous with the pool surface of the mixing chamber. The formation of the vortex promotes the contact between the various particles contained in the gas stream that mixes with the liquid, and causes the particles to stay in the vortex chamber for a long time. In addition, due to the centrifugal force generated by the vortex, a part of the liquid having a higher specific gravity flows along the inner wall surface of the cylindrical surface of the vortex chamber, and the paint particles and the like contained in the airflow are also particles having a very high specific gravity. Therefore, it is trapped in the liquid flowing down on the inner wall surface. Therefore, the trapping of the particles contained in the airflow into the liquid proceeds remarkably, and the so-called short-path phenomenon in which a part of the airflow flows toward the exhaust fan mechanism without mixing with the liquid does not occur. In short, the formation of the vortex significantly contributes to the improvement of the particle trapping efficiency. In addition, since the liquid continues to flow on the inner wall surface of the vortex chamber, it is possible to prevent the trapped particles from remaining on the inner wall surface while remaining attached thereto. It can be kept clean for a long time without performing the cleaning work. The spiral body is a structure that slows down the above-mentioned "vortex of the mixture of air and liquid", makes it stay for a long time, and then discharges it outside the wet scrubber. The structure is connected in communication with the swirl chamber and has a helically curved inner wall surface that is continuous with the inner wall surface of the swirl chamber and has a steadily increasing flow cross-section, with the expanded outlet facing downward. In preparation. Thus, since the decelerated "air and liquid mixture vortex" stays in the spiral for a long time before being released out of the wet scrubber, the vortex is less attenuated in its energy and more Longer duration, during which the particles in the gas stream come into contact with the liquid more often and more frequently, resulting in more efficient particle capture. Also, since the "vortex of the air-liquid mixture" is released after being sufficiently decelerated in the volute, the pressure is restored by the decrease in the dynamic pressure, and therefore, the "vortex" flows out of the wet scrubber. The pressure loss at the stage of release is less. Suitable swirls include, for example, an air stream having a wind speed of 2
When introduced into the mixing chamber at 0-40 m / s,
It has the ability to decelerate the "vortex of the mixture of air and liquid" from the vortex chamber and discharge at a wind speed of 5 m / s or less.

In the present invention, the swirl chamber and the spiral body are not provided in parallel with each other, but are provided so that the internal spaces of the swirl chamber and the spiral body partially share one another in an intersecting relationship. Therefore, in the internal space of these structures, there is formed a flow passage through which the mixture of the airflow and the liquid flows while being restricted in a spiral spiral, that is, a substantially spiral spiral passage. At the same time, in the present invention, the swirl chamber and the spiral body together have an inner wall surface on which the liquid for trapping flows in a substantially spirally restricted manner, that is, the substantially spiral spiral flow. An inner wall surface surrounding the road is formed. Therefore, in the swirl-type wet scrubber of the present invention, the mixture of the gas stream and the liquid is spread from the swirl chamber to the swirl body.
A spiral vortex flows through these internal spaces, that is, a substantially perfect vortex is formed. Simultaneously with the formation of this vortex, the liquid for particle trapping flows substantially spirally on the inner wall surfaces of both the vortex chamber and the swirl body, thereby providing sufficient liquid for the liquid over the entire inner wall surface. A film having a thickness is formed. Therefore, although the swirl-type wet scrubber of the present invention has a structure in which the unit of the swirl chamber and the swirl body is provided only on one side, a so-called water splash does not occur because a complete form of the swirl is formed, The trapping performance of the particles in the air stream is further improved, and the unit can exhibit good scrubber performance comparable to the performance of a vortex-type wet scrubber having a structure provided on both sides, and the inside of the unit can be exhibited. Since a liquid film having a sufficient thickness is formed on the entire wall surface, problems such as accumulation of particles and generation of stains due to deposition of paint particles do not occur.

[0012]

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.

FIG. 1 shows a paint spray booth 10 used for spray painting a car body in a car factory.
Is shown inside. The booth 10 is divided into three smaller compartments: an air supply chamber 6 at the top, a spray chamber 7 at the center, and a scrubber chamber 8 at the bottom. Booth 10
It is connected to an exhaust duct 11, which is guided to an exhaust fan mechanism (not shown). A filter 12 is stretched and fixed to the supply chamber 6 at a boundary between the compartment and the spray chamber 7. The air supply chamber 6 is also equipped with a bag filter 13. Therefore, after the dust in the air is removed by the bag filter 13 and the filter 12, the temperature- and humidity-controlled air is supplied to the spray chamber 7 as a vertically descending airflow. In the spray chamber 7, a coating robot 14 or other automatic coating device for performing automatic spray coating on the vehicle body 15 is provided.
6 is provided on each of the left and right sides of the path conveyed on the vehicle. Therefore, the surplus paint that has not adhered to the vehicle body 15 during painting floats in the air as paint mist. As shown in FIG. 2, a flow plate 17 is stretched above the scrubber chamber 8, and an opening 18 is formed in the center of the flow plate 17. The wet scrubber 1 of the present embodiment is mounted on the flow plate 17 by fixing the acceleration cone 2 to the opening 18. Therefore, the air (including the paint mist) in the spray chamber 7 is sucked by the operation of the exhaust fan mechanism (not shown), and is introduced into the wet scrubber 1 as a descending exhaust airflow. And is supplied into the exhaust chamber 9. The wet scrubber 1 is used to trap and remove paint particles contained in the exhaust air stream from the spray chamber 7. Gutters 19, 19 are provided on the left and right sides of the flow plate 17, respectively. The water supply pipes 21, 21 piped from the pumps 20, 20, respectively,
Pumps 20, 20 are introduced into the gutters 19, 19
Operation causes water to flow into the left and right gutters 19, 19
Respectively. Then, the water d (FIG. 2) overflows from the left and right gutters 19, 19, flows on the left and right flow plates 17, respectively, to form a shallow water pool, and then near the center thereof, the wet scrubber 1 The gas flows over the periphery of the entrance of the acceleration cone 2 and flows into the acceleration cone 2 (FIGS. 1 and 2). The water d is a liquid for trapping paint particles contained in the airflow. The scrubber chamber 8 has an exhaust chamber 9 continuous with the wet scrubber 1 therein. The exhaust chamber 9 is connected to an exhaust duct 11, and communicates with the exhaust fan mechanism via the exhaust duct 11. A drain 2 is provided at the bottom of the exhaust chamber 9.
2 is provided in which water containing paint discharged from the wet scrubber 1 collects. Some mist separators 23 are provided in the air flow passage communicating with the exhaust fan mechanism.
・ ・ Is attached. In addition, as shown in FIG.
The paint spray booth 10 is provided with a plurality of wet scrubbers 1... In the longitudinal direction of the scrubber chamber 8, that is, in the same direction as the direction in which the vehicle body 15 is transported along its transport path, usually at substantially equal intervals. (For example, 1.5 m to 3.
0 m). The connection from the exhaust chamber 9 to the exhaust duct 11 is such that they are arranged alternately and symmetrically (FIG. 6).

FIG. 3, FIG. 4, and FIG. 5 are a front view, a plan view, and a side view, respectively, of a vortex-type wet scrubber 1 of the present embodiment mounted on a flow plate 17 of a paint spray booth 10. Show. The swirl-type wet scrubber 1 of the present embodiment includes an acceleration cone 2, a mixing chamber 3, a swirl chamber 4, and a swirl body 5, and a unit of the swirl chamber 4 and the swirl body 5 is disposed only on one side of the mixing chamber 3. It is a wet scrubber with a structure. The accelerating cone 2 is a structure in which an air flow passes therethrough and is accelerated. The accelerating cone 2 has a circular inlet 25 at an upper end, a rectangular (square) outlet 26 at a lower end, and an inlet 25 to an outlet 26. And an inner peripheral wall 24 surrounding the passage (FIG. 4). This inner peripheral wall 24
Is a curved inner peripheral wall having no corners, and has a structure in which the opening cross-sectional area decreases from the inlet 25 to the outlet 26. Therefore, the acceleration cone 2 has a shape similar to a funnel. I have. Accordingly, when the exhaust airflow from the spray chamber 7 (indicated by an arrow e in FIG. 3) passes through the inside of the acceleration cone 2 downward, the speed of the downward airflow gradually increases. At this time, the airflow in a region near the inner peripheral wall 24 of the cone is accelerated more greatly than the airflow in a region near the centerline of the cone. Also, the inner peripheral wall 2
Although not shown in detail, in order to minimize the pressure loss of the air flow when passing through the accelerating cone 2, there is no corner portion over one round and the outlet 26 of the accelerating cone 2
The inner peripheral wall has a multidimensional curved surface (generally, a curved surface close to a parabolic curved surface) such that the velocity of the discharged airflow is substantially uniform over the entire exit cross section. The design of this multi-dimensional curved surface is based on the hydrodynamic numerical values based on the cross-sectional area of the inlet 25 of the accelerating cone 2, the cross-sectional area of the outlet 26, and the height of the accelerating cone 2 (the distance between the inlet 25 and the outlet 26). It is automatically determined by computer calculation through analysis. For example, the shape of the inner peripheral wall 24 is such that the airflow at the outlet 26 of the acceleration cone 2
It is set so as to have a uniform speed of m / s to 40 m / s. Therefore, at the stage where the air flow passes through the acceleration cone 2, the air flow is smoothly accelerated and the speed of the air flow discharged from the outlet 26 of the acceleration cone 2 (indicated by an arrow e 'in FIG. 3). Is substantially uniform over the entire cross section of the outlet 26. Thus, the pressure loss required to achieve an airflow velocity suitable for trapping particles in the airflow can be reduced to a minimum and noise can be substantially reduced. On the other hand, the water d in the shallow water pool on the flow plate 17 flows into the accelerating cone 2 over the inlet edge 27 of the accelerating cone 2 for trapping the particles. The water d supplied into the accelerating cone 2 flows down on the multidimensional curved surface of the inner peripheral wall 24 of the accelerating cone 2, and flows down from the peripheral edge 28 of the accelerating cone 2 through the outlet 26 at the lower end, thereby flowing through the accelerating cone 2. Along with the passing airflow,
It is introduced into the mixing chamber 3 below the accelerating cone 2. In FIG. 3, a indicates a water film formed on the inner peripheral wall 24 and flowing down on the surface thereof. The mixing chamber 3 is a chamber disposed below and in communication with the outlet 26 of the accelerating cone 2 and in which the exhaust gas flow (arrow e ′ in FIG. 3) and the water film a (FIG. 9) are introduced together for impingement mixing. The mixing chamber 3 has a pool 30 for collision directly below the outlet 26 of the acceleration cone 2.
The pool 30 is a pool composed of a part of a circular surface, a part of an elliptical peripheral surface, or a part of another similar curved surface. Accumulate. The exhaust airflow that has passed through the acceleration cone 2 (arrow e ′ in FIG. 3) is blown out from an outlet 26 of the acceleration cone 2 toward a pool 30 in which water is accumulated,
Violently collides with the water in the pool 30. Further, the discharge airflow e ′ is also mixed with a water curtain b (FIG. 3) formed by water flowing down from the outlet peripheral edge 28 of the acceleration cone 2. In short, in the internal space of the mixing chamber 3, the exhaust airflow e ′ that has been vigorously discharged downward from the outlet 26 through the acceleration cone 2 collides violently with the water in the pool 30 that has flowed down from the peripheral edge 28 of the outlet 26. Mixed with
The water in the curtain water stream b is also mixed violently. In this embodiment, the nozzle adjusting plate 29 is suspended from the outlet 26 of the acceleration cone 2 so as to face the inner wall surface of the mixing chamber 3. The adjusting plate 29 can freely change the cross-sectional area of the lower flow path from the outlet 26 of the acceleration cone 2 by tilting inward or outward. By expanding or reducing the cross-sectional area near the outlet 26 by tilting the nozzle adjustment plate 29, the speed of the exhaust airflow toward the pool 30 can be controlled. Thereby, the collision mixing of the exhaust airflow and the water in the mixing chamber 3 can be made more efficient.

The vortex chamber 4 is a substantially cylindrical chamber capable of forming a vortex by circulating the mixture of the gas flow and the liquid, and the chamber 4 is provided at a side of the mixing chamber 3. Connected in communication with this, and
It has an inner wall surface 31 in which the liquid flows over its surface as the gas and liquid mixture circulates. The inner wall surface 31 has a cylindrical peripheral surface that is continuous with the surface of the pool 30 of the mixing chamber 3. Therefore, the discharged airflow e ′ (FIG. 3) that has collided with and mixed with water in the mixing chamber 3 is then directed toward the vortex chamber 4, passed through the water curtain b, and introduced into the vortex chamber 4. You. As soon as the mixture of air and water flows into the swirl chamber 4, it begins to orbit, and the flows swirl, forming a swirl f. Due to the effect of inertia, the energy of the exhaust airflow e ′ passing through the water curtain b is directly converted to energy in which the mixture of air and water forms the vortex f with little attenuation, and as it is as vortex energy Will be maintained. Therefore, the pressure loss at the stage where the mixture of the exhaust gas flow e ′ and the water moves from the mixing chamber 3 into the vortex chamber 4 to form the vortex f is minimized. The vortex f causes, due to the action of the centrifugal force acting thereon, water droplets having a higher specific gravity among various types of particles contained therein to move from the center of the vortex chamber 4 toward the inner wall surface 31. Therefore,
Some of the water is propelled to flow along the vortex f over the inner wall surface 31 of the vortex chamber 4. At the same time, the vortex f also causes very high specific gravity particles, paint particles and the like contained therein to move toward the inner wall surface 31 of the vortex chamber 4 and to flow along the inner wall surface 31 (see c in FIG. 3).
Indicated by ). Therefore, paint particles and the like are captured in the water c. There, the paint particles come into contact with each other, agglomerate to form larger particles, and mix with water c. As a result, the capture of the paint particles contained in the exhaust airflow by the water film c proceeds more and more.
In addition, the swirl f allows the paint particles contained therein to stay in the swirl chamber 4 for a long time.
Thus, the chance and frequency of contact of the paint particles with the water for capture increases. The spiral body 5 is a structure that slows down the vortex f of the “mixture of air and water”, stays for a considerably long time, and then discharges it outside the wet scrubber 1. And connected to it. The spiral body 5 has a helically curved inner wall surface 32 that is continuous with the inner wall surface 31 of the vortex chamber 4 and has a gradually increasing flow cross-sectional area, and has an extended outlet 33 facing downward. Therefore, the “mixed vortex of air and water” guided from the vortex chamber 4 to the volute 5, after being sufficiently decelerated in the volute 5, preferably to a speed of about 10 m / s or less, It is discharged downward from the outlet 33 outside the wet scrubber 1 (indicated by an arrow g in FIG. 3). Since the “mixed vortex of air and water” is released after being sufficiently decelerated in the spiral body 5, the static pressure is restored by the decrease of the dynamic pressure, and thus the “mixed vortex” is out of the wet scrubber 1. The pressure drop during the discharge phase is smaller and minimized. For example, when a gas flow is introduced into the mixing chamber 3 from the acceleration cone 2 at a wind speed of 20 to 40 m / s, the preferable spiral body 5 can reduce the above-described “mixed vortex of air and water” to a wind speed of 5 m / s or less. It has the performance of decelerating and releasing. Also, the inner wall surface 31 of the vortex chamber 4
The water containing a large amount of paint particles flowing upward flows along the inner wall surface 32 of the spiral body 5, is decelerated, and is discharged downward from the outlet 33 together with the clean air. . Thereafter, the water containing the paint particles is collected at the drain 22 (FIG. 2) in the exhaust chamber 9.

In this embodiment, as shown in FIG.
The swirl chamber 4 and the swirl body 5 are provided in such a manner that the internal spaces of the swirl chambers 4 and the swirl bodies 5 partially share each other in an intersecting arrangement relationship.
In the internal space of these structures, a flow path through which a mixture of airflow and water flows while being restricted in a spiral vortex (in the figure,
p) is formed. Further, in this embodiment, the inner surface of the vortex chamber 4 and the spiral body 5
Are formed so as to surround the above-mentioned substantially spiral vortex flow path together, so that the water on the surface is substantially spirally restricted and flows. Therefore, in the wet scrubber 1 of the present embodiment, the mixture of the air current and the water flows from the swirl chamber 4 to the spiral body 5 and spirally spirals in the internal space in the p direction in the drawing, and thus substantially. A perfect form of vortex is formed. At the same time as the formation of the complete vortex, the water for trapping particles flows substantially spirally on the inner wall surface 31 of the vortex chamber 4 and the inner wall surface 32 of the spiral body 5. Therefore, a water film having a sufficient thickness is formed over the entire inner wall surfaces 31 and 32. Therefore, the so-called water splash does not occur due to the formation of the perfect form of the vortex,
The ability to trap particles in the airflow is improved, and the formation of a sufficiently thick water film over the inner wall surfaces 31, 32 allows water to continue to flow on these inner wall surfaces 31, 32. This prevents the trapped paint particles and the like from adhering to and remaining on the inner wall surfaces 31 and 32 and causing a situation in which they are soiled. Therefore, the inside of the wet scrubber 1 is
It can be kept clean for a long time without performing any special cleaning work. In addition, the pressure loss of the exhaust air flowing through the wet scrubber 1 is kept to a minimum, so that energy consumption is reduced and noise is reduced.

Comparative Example FIGS. 7, 8 and 9 show a front view, a plan view and a side view, respectively, of a swirl type wet scrubber 40 of a comparative example mounted on the flow plate 17 of the paint spray booth 10. . The wet scrubber 40 of the comparative example is the same as the wet scrubber 1 of the above-described embodiment except that the vortex chamber 4 and the spiral body 5 are provided in parallel as clearly shown in FIG. It constitutes a configuration. In the wet scrubber 40 of this comparative example, since the vortex chamber 4 and the spiral body 5 are provided in parallel, the internal space of these structures is, as shown in FIG.
Although a curved flow path indicated by an arrow q is formed, a flow path through which a mixture of airflow and water can flow in a spiral spiral is not formed. Further, the inner wall surface 31 of the vortex chamber 4 and the inner wall surface 32 of the spiral body 5 are only adjacent to each other independently, but are not configured to surround the substantially spiral vortex flow path together. Thus, the wet scrubber 40
In operation, the water does not flow sufficiently over the inner wall surface 31 of the swirl chamber 4 and the inner wall surface 32 of the swirl 5 and the "mixture with air and water" becomes an imperfect form of swirl. Therefore, it passes through the inside of the wet scrubber 1 and is released. Therefore, the performance of removing particles in the airflow (scrubber performance) was very poor as compared with the wet scrubber 1 of the embodiment. In addition, the wet scrubber 40 is used to prevent water from
8, a portion where a water film having a sufficient thickness is not formed at the corner of the vortex chamber 4 or the corner of the spiral body 5 as shown in FIG. ), And paint particles and the like in the airflow tended to deposit and accumulate on such sites, and after a short period of use, the inside of the wet scrubber became dirty.

[0018]

As described above, according to the present invention,
For a swirl type wet scrubber having a structure of a swirl chamber and a swirl unit only on one side, a perfect form of swirl can be reliably formed, and at the same time, a liquid film for particle capture is formed in the unit. It can be formed on the entire inner wall surface, so that the efficiency of trapping particles in the air stream can be improved, the desired scrubber performance can be achieved, and the generation of dirt due to the deposition of particles inside the wet scrubber can be reduced. Therefore, the cleaning and maintenance of the inside of the slab can be made easier. Therefore, the swirl-type wet scrubber of the present invention has an advantage that it can be conveniently applied to an area of a paint spray booth used for painting an automobile body or the like, in which a smaller amount of exhaust air is sucked. further,
The swirl-type wet scrubber of the present invention, in addition to such improvements, can also significantly reduce energy consumption and noise by minimizing pressure loss. Further, according to the present invention, there is also obtained an effect that it is possible to provide a paint spray booth provided with the above-mentioned improved swirl type wet scrubber.

[Brief description of the drawings]

FIG. 1 is a schematic view showing the inside of a paint spray booth equipped with a wet scrubber according to an embodiment of the present invention.

FIG. 2 is an enlarged view showing a lower portion of the paint spray booth shown in FIG. 1, particularly a vicinity of a wet scrubber in a scrubber room.

FIG. 3 is a front view of the wet scrubber of the embodiment shown in FIG. 1;

FIG. 4 is a plan view of the wet scrubber of the embodiment shown in FIG. 1;

FIG. 5 is a side view of the wet scrubber of the embodiment shown in FIG. 1;

FIG. 6 is a view of the scrubber chamber of the paint spray booth as viewed from above, and is a diagram showing a state of arrangement of the wet scrubber of the embodiment.

FIG. 7 is a front view of a wet scrubber of a comparative example.

FIG. 8 is a plan view of a wet scrubber of a comparative example.

FIG. 9 is a side view of a wet scrubber of a comparative example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Wet scrubber 2 Acceleration cone 3 Mixing chamber 4 Swirl chamber 5 Spiral body 6 Air supply chamber 7 Spray chamber 8 Scrubber chamber 9 Exhaust chamber 10 Paint spray booth 17 Flow plate 18 Opening 24 Inner peripheral wall 25 Inlet 26 Outlet 27 Inlet peripheral 30 Pool 31 inner wall surface 32 inner wall surface 33 discharge port a water flowing down the inner peripheral wall of the acceleration cone b water flowing down into the mixing chamber c water flowing on the inner wall surface of the vortex flow chamber d liquid for trapping e discharge air flow e 'acceleration cone F the vortex formed by a mixture of airflow and liquid g the discharged airflow p spiral vortex flow path in the internal space of both the vortex chamber and the vortex

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kaoru Inabayashi 1-9-9 Kakimotocho, Toyota City, Aichi Prefecture Inside Trinity Industry Co., Ltd. (72) Inventor Hidetoshi Omori 1-9-9 Kakimotocho, Toyota City, Aichi Prefecture Trinity (72) Inventor Mikio Murachi 1-9-9 Kakimotocho, Toyota City, Aichi Prefecture Trinity Industry Co., Ltd. F-term (reference) 4D073 AA09 BB05 DC02 DC12

Claims (3)

[Claims] 1. A wet scrubber for removing particles contained therein from an air stream, wherein the cone is a stream through which the air stream is accelerated, the inlet at the upper end, the outlet at the lower end, and the cross-sectional area of the cone. An accelerating cone having an inner peripheral wall surrounding a passage which is reduced from the inlet to the outlet, and having an inner peripheral wall through which a liquid for trapping particles in an air flow can flow down from an inlet peripheral edge to an outlet peripheral edge; A mixing chamber disposed below and in communication with the outlet for impinging and mixing an airflow passing through the acceleration cone with a liquid for trapping that has flowed down from an outlet periphery of the acceleration cone; A substantially cylindrical chamber connected to and communicated with a side of the mixing chamber to form a swirl by circulating a mixture of gas and liquid, wherein the mixture of gas and liquid circulates. Liquid on its surface A swirl chamber having an inner wall surface flowing therethrough, and a swirl body connected in communication with the swirl chamber and configured to decelerate the mixture of the airflow and the liquid and discharge the mixture through an expanded outlet, A spiral body having an inner wall surface continuous with the inner wall surface of the swirl chamber, and provided such that the internal spaces of the swirl chamber and the spiral body partially share one another in an intersecting relationship, The internal space defines a flow path through which the mixture of the gas flow and the liquid is restricted in a spiral form and flows therethrough, and the swirl chamber and the spiral form together form a substantially spiral liquid for trapping. A swirl-type wet scrubber characterized by forming an inner wall surface which is restricted and transmitted. 2. A swirl-type wet scrubber according to claim 1, wherein the wet scrubber uses water as a liquid for trapping particles and removes paint particles contained therein from an exhaust stream containing paint mist. Scrubber. 3. a) a spray chamber in which the object is spray-coated; b) a scrubber chamber located below the spray chamber and having a flow plate having an opening at the top thereof; c. 3.) a swirl-type wet scrubber according to claim 1 or 2, wherein an accelerating cone is fitted in the flow plate of the scrubber chamber so as to fit into the opening of the flow plate; and d) for trapping paint particles. Water supply means for supplying water onto the flow plate and flowing onto the inner peripheral wall of the accelerating cone of the wet scrubber; ande) exhaust air from the spray chamber containing paint particles to be removed to the wet scrubber. A paint spray booth equipped with an exhaust mechanism that draws through.