Wet mist collection device

Abstract

The present invention addresses the problem of providing a wet mist collection device reduced in height to have a small size and capable of efficiently collecting mist by facilitating the separation of mist from air. A wet mist collection device 1 according to the present invention is provided with: a mist treatment tank 10 forming a depressurized space S inside with water 2 stored therein, in which air containing mist is sucked, the mist contained in the air is taken in the water 2, and the mist is separated from the air; a mist collection tank 20 in which atmospheric pressure is maintained, and the mist separated from the air in the mist treatment tank 10 is collected; a sludge collection tank 30 in which the mist collected in the mist collection tank 20 is collected as sludge 4; and an exhaust blower 40 connected to the mist treatment tank 10.

Description

Technical Field

[0001] The present invention relates to a wet mist collection device for collecting mist from air containing mist through water.

Background Art

[0002] For example, a part of the paint mist sprayed by spray painting in a painting chamber (spray booth) does not adhere to the object to be painted, scatters around as overspray, re-adheres to the object to be painted, or fills the painting chamber, causing a problem of deteriorating the working environment.

[0003] Therefore, various mist collection devices have been proposed so far for collecting the paint mist scattered in the painting chamber. The paint mist collection methods by the mist collection devices are roughly classified into dry and wet types. Here, the dry type uses the adhesiveness of the paint and a filter to collect the paint mist. According to this method, the paint mist can be easily repaired only by performing maintenance such as replacing the filter, but there is a problem of low collection efficiency.

[0004] On the other hand, the wet type generally uses water to collect the paint mist and removes the collected paint mist as sludge, and has an advantage of obtaining high collection efficiency.

[0005] By the way, regarding wet mist collection devices, proposals have been made in, for example, Patent Documents 1 and 2.

[0006] That is, Patent Document 1 proposes a wet mist collection device that forms a painting chamber (spray booth) and a mist treatment chamber partitioned by a water flow plate in the device body, arranges a water tank portion below these, and arranges a fan above the mist treatment chamber. According to this wet mist collection device, the treated water that has overflowed from the overflow tank arranged above the water flow plate flows along the water flow plate to form a water film, and the paint mist generated in the painting chamber collides with the water film along the water flow plate, and most of it is taken into the treated water and collected.

[0007] In addition, Patent Document 2 proposes a wet mist collection device disposed below a painting chamber (painting booth). The wet mist collection device includes a collection unit, a water supply device, a first water guide plate, a collection chamber, and a blower. According to this wet mist collection device, air containing painting mist sucked from the painting chamber passes through the collection unit together with water, so that the painting mist is separated from the air and collected. Then, a flocculant is added to the water that has taken in the painting mist, and the painting mist contained in the water aggregates into sludge. The water and the sludge are separated by a separation device provided in the collection chamber.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0009] However, since the wet mist collection devices proposed in Patent Documents 1 and 2 are both integrally provided below the painting chamber (painting booth), there is a problem that the overall height of the wet mist collection device including the painting chamber becomes high and the device becomes large-sized. In addition, since the air containing painting mist is made to collide with water flowing along a water flow plate or the like to separate the painting mist contained in the air and take it into the water, there is also a problem that the separation efficiency of the painting mist from the air is poor.

[0010] The present invention has been made in view of the above problems, and an object thereof is to provide a wet mist collection device that can be reduced in size while suppressing the height, and that can promote the separation of mist from air and efficiently collect the mist.

Means for Solving the Problems

[0011] To achieve the above object, a wet mist collection device (1) according to the present invention comprises a mist treatment tank (10) that forms a decompressed space (S) in which water (2) is stored, sucks air containing mist, takes the mist contained in the air into the water (2), and separates the mist from the air; a mist recovery tank (20) in which the interior is maintained at atmospheric pressure and the mist separated from the air in the mist treatment tank (10) is recovered; a sludge recovery tank (30) that recovers the mist recovered in the mist recovery tank (20) as sludge (4); and an exhaust blower (40) connected to the mist treatment tank (10).

[0012] According to the present invention, since the mist treatment tank, the mist recovery tank, and the sludge recovery tank are provided separately from the room where the mist is generated, the height of the wet mist collection device can be kept low and its miniaturization can be achieved. Further, since the sludge of the mist is recovered in two stages in the mist treatment tank and the mist recovery tank, the sludge recovery efficiency is enhanced, and as a result, the mist collection efficiency of the wet mist collection device is enhanced.

[0013] In the above wet mist collection device (1), the mist treatment tank (10) may be provided with a pump (17) that pumps a part of the mist separated from the air and the water (2) containing the mist in the mist treatment tank (10) to the mist recovery tank (20).

[0014] According to the above configuration, by pumping a part of the mist separated from the air and the water containing the mist in the mist treatment tank to the mist recovery tank by a pump, the mist (sludge) can be efficiently recovered in the mist recovery tank.

[0015] Further, in the above wet mist collection device (1), the mist recovery tank (20) may be provided with a pump (23) that pumps the sludge (4) of the mist to the sludge recovery tank (30).

[0016] According to the above configuration, the sludge recovered in the mist recovery tank can be pumped and transferred to the sludge recovery tank for recovery.

[0017] Further, in the wet mist collector (1), a pump (24) for returning water (2) to the mist treatment tank (10) may be provided in the mist recovery tank (20).

[0018] According to the above configuration, since the water accumulated in the mist recovery tank is returned to the mist treatment tank by the pump, water circulates between the mist treatment tank and the mist recovery tank and does not flow out to the outside. Operations such as discarding water or replacing it with new water become unnecessary, and effective utilization of resources and labor saving can be achieved.

[0019] Further, in the wet mist collector (1), comb-shaped bubbling means (13) for bubbling air containing mist in water may be provided in the mist treatment tank (10).

[0020] According to the above configuration, due to the bubbling of the air containing mist in water by the bubbling means in the mist treatment tank, mist is separated from the air (mist-containing air) and efficiently taken into the water, so the mist collection efficiency of the wet mist collector is improved.

[0021] Further, in the wet mist collector (1), gas-liquid separation means (14) for separating and removing air from water containing air may be provided in the mist treatment tank (10).

[0022] According to the above configuration, since the gas-liquid separation means surely separates the two based on the difference in specific gravity between water and air and surely removes air from water, clean air from which moisture and mist have been removed can be discharged into the atmosphere.

[0023] In addition, in the wet mist collection device (1), a tank (31) for collecting the recovered sludge (4) and discarding it outside the sludge recovery tank (30) may be detachably provided in the sludge recovery tank (30).

[0024] According to the above configuration, when sludge accumulates in the tank, the tank can be removed from the sludge recovery tank, and the sludge accumulated in the tank can be discarded at a predetermined disposal location, thus facilitating the disposal of the sludge.

Effect of the Invention

[0025] According to the present invention, it is possible to obtain the effect of suppressing the height of the wet mist collection device to reduce its size and promoting the separation of mist from air to efficiently collect the mist.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

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Figure 10

Embodiments for Carrying Out the Invention

[0027] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0028] [Configuration of Wet Mist Collection Device 1] FIG. 1 is a side view of a wet mist collection device according to the present invention, FIG. 2 is a plan view of the same wet mist collection device, FIG. 3 is a view in the direction of arrow A in FIG. 1, FIG. 4 is a plan view of an inlet cover, FIG. 5 is a side view of the same inlet cover (a view in the direction of arrow B in FIG. 4), FIG. 6 is a cross-sectional view taken along line C-C in FIG. 5, FIG. 7 is a plan view of a scrubber, FIG. 8 is a cross-sectional view taken along line D-D in FIG. 7, FIG. 9 is a view in the direction of arrow E in FIG. 8, and FIG. 10 is a schematic cross-sectional view showing the operation of the wet mist collection device according to the present invention. In the following description, the front side and the back side of the drawing sheet of FIG. 1 (the same as the front side and the back side shown in FIG. 2) are referred to as the front side and the back side of the wet mist collection device, respectively, and the left side and the right side of FIGS. 1 and 2 are referred to as the left side and the right side of the wet mist collection device, respectively.

[0029] The wet mist collection device 1 shown in FIGS. 1 and 2 is a device for collecting paint mist generated by painting work in a painting chamber (paint booth) 100 shown in FIG. 10, and includes a rectangular tank-shaped mist treatment tank 10, a mist recovery tank 20, and a sludge recovery tank 30 arranged side by side on the ground, and an exhaust blower 40 is installed beside the mist treatment tank 10.

[0030] As shown in FIG. 10, the inside of the mist treatment tank 10 constitutes a sealed decompression space S, and a predetermined amount of water 2 is stored at the bottom of this decompression space S. Also, as shown in FIG. 2, the inside of the mist treatment tank 10 is partitioned by a partition wall 10A into a first chamber 10a on the right side and a second chamber 10b on the left side. The first chamber 10a and the second chamber 10b communicate with each other through an opening 10B provided at the front side position inside the mist treatment tank 10, and air and water 2 inside the mist treatment tank 10 flow from the first chamber 10a to the second chamber 10b through the opening 10B. Note that the illustration of the partition wall 10A and the opening 10B is omitted in FIG. 1.

[0031] Then, as shown in Fig. 10, one end (discharge end) of the suction pipe 3 extending in an inverted U shape from the upper part of the painting chamber (spray booth) 100 is vertically inserted from above at a position on the back side of the first chamber 10a of the mist treatment tank 10, and one end of this suction pipe 3 opens into the water 2 stored in the first chamber 10a. Here, as shown in Fig. 2, a part of the upper wall of the mist treatment tank 10 is constituted by a detachable rectangular flat plate-shaped inlet cover 11. As shown in Figs. 4 and 5, one end of each of the suction pipe 3 and the small-diameter pipe 25 penetrates vertically through the inlet cover 11. And one end of each of these suction pipe 3 and pipe 25 is immersed in the water 2 stored at the bottom in the mist treatment tank 10.

[0032] By the way, an air bubbler 13 as bubbling means as shown in Figs. 4 to 6 is attached to the end portion immersed in the water 2 at one end of the suction pipe 3 vertically inserted into the first chamber 10a in the mist treatment tank 10. This air bubbler 13 is configured by forming a plurality of comb-shaped teeth 13a on the outer periphery of the cylinder 13A at an equal angular pitch over the entire circumference, and a vertically long gap δ is formed between two adjacent teeth 13a. Note that the specific shapes of the teeth 13a formed on the cylinder 13A and the gap δ are not limited to those shown in the drawings. For example, as the shapes of the teeth 13a and the gap δ, the width dimension of the teeth 13a may gradually decrease from the upper side to the lower side, and the width dimension of the gap δ may gradually increase from the upper side to the lower side. Or the longitudinal shape in which the length dimensions (vertical dimensions) of the teeth 13a and the gap δ are longer than their width dimensions is also possible.

[0033] Also, a scrubber 14 as a gas-liquid separation means shown in FIGS. 7 to 9 is disposed at a location adjacent to the front side of the foaming device 13 in the first chamber 10a. This scrubber 14 is installed at a position facing the foaming device 13 and includes a vertical wall 14A in the shape of a rectangular flat plate standing vertically, an upper wall 14B and a lower wall 14C extending from above and below the vertical wall 14A, and a vertical partition wall 14D partitioning the space formed by the vertical wall 14A, the upper wall 14B, and the lower wall 14C. Inside this scrubber 14, a first flow path F1 that is long in the vertical direction is formed by the vertical wall 14A, the partition wall 14D, and the lower wall 14C, a second flow path F2 is formed by the partition wall 14D, the lower wall 14C, and the upper wall 14B, and a third flow path F3 is formed by the upper wall 14B and the lower wall 14C. Here, the first to third flow paths F1, F2, and F3 constitute a maze.

[0034] Here, as shown in FIGS. 8 and 9, inlets 14a that open into the first flow path F1 are respectively formed above and below the vertical wall 14A. Also, as shown in FIG. 8, the first flow path F1 and the second flow path F2 communicate with each other through a communication port 14b, and the second flow path F2 and the third flow path F3 communicate with each other through a communication port 14c. An outlet 14d that opens into the first chamber 10a of the mist treatment tank 10 is formed in the third flow path F3.

[0035] Also, as shown in FIG. 10, in the second chamber 10b of the mist treatment tank 10, a recovery container 15 for recovering the sludge 4 of the coating mist that forms a layer and stays above the water 2 stored at the bottom is provided, and a pipe 16 is connected to the bottom of this recovery container 15. This pipe 16 extends downward from the bottom of the recovery container 15 and then is bent upward, but a pump (P) 17 provided in the water 2 is connected in the middle thereof. Then, the pipe 16 penetrates the upper wall of the mist treatment tank 10 and extends to the outside, is bent in an inverted U shape and faces vertically downward, and penetrates the upper wall of the mist recovery tank 20 and opens into the inside of the mist recovery tank 20.

[0036] Furthermore, as shown in FIG. 1, a rectangular duct 18 is attached to the upper part of the back side of the second chamber 10b of the mist treatment tank 10, and an intake pipe 5 opens into this duct 18. Here, as shown in FIG. 1, a filter 19 is provided inside the duct 18.

[0037] As shown in FIG. 1, after the intake pipe 5 exits the duct 18, it is bent at a right angle and extends horizontally, then bent at a right angle and directed downward. As shown in FIGS. 2 and 3, the lower end thereof is bent at a right angle toward the exhaust blower 40, and the end thereof is connected to the intake port at the center of the exhaust blower 40.

[0038] The mist recovery tank 20 recovers and stores the sludge 4 of the paint mist sent together with the water 2 from the mist treatment tank 10, and the pressure inside it is maintained at atmospheric pressure. And inside this mist recovery tank 20, as shown in FIG. 10, a recovery container 21 for recovering the sludge 4 that forms a layer and floats on the water 2 is provided, and a pipe 22 is connected to the bottom of this recovery container 21. Here, the pipe 22 extends downward from the bottom of the recovery container 21 and then is bent upward, and a pump (P) 23 is connected to the portion immersed in the water 2. And the pipe 22 penetrates the upper wall of the mist recovery tank 20 and is bent in a U shape, and the end thereof penetrates the upper wall of the sludge recovery tank 30 and opens into the inside of the sludge recovery tank 30.

[0039] Also, a pump (P) 24 is provided in the water 2 stored in the mist recovery tank 20. The pipe 25 extending upward from this pump 24 penetrates the upper wall of the mist recovery tank 20 and is then bent in an inverted U shape and directed downward, and penetrates the upper wall of the mist treatment tank 10 and opens into the decompression space S of the mist treatment tank 10.

[0040] On the other hand, as shown in FIGS. 1 to 3, the exhaust blower 40 operates with the motor 41 as a drive source, and an exhaust pipe 6 is connected to its discharge port. The exhaust pipe 6 has a portion connected to the discharge port of the exhaust blower 40 bent at a right angle and extending upward, and its end is open to the atmosphere.

[0041] [Operation of Wet Mist Collection Device 1] Next, the operation of the wet mist collection device 1 configured as described above will be explained.

[0042] When the exhaust blower 40 is rotationally driven by the motor 41, the air inside the mist treatment tank 10 is sucked from the intake pipe 5 into the exhaust blower 40, so that the inside of the mist treatment tank 10 is maintained at a negative pressure and becomes a decompression space S.

[0043] Then, the air containing paint mist generated by the painting operation in the painting chamber (paint booth) 100 (hereinafter referred to as "mist-containing air") is drawn into the mist treatment tank 10 from the suction pipe 3 by the negative pressure in the decompression space S of the mist treatment tank 10, as shown by the arrows in FIGS. 1, 2, and 10.

[0044] The mist-containing air drawn by the negative pressure in the decompression space S of the mist treatment tank 10 and flowing through the suction pipe 3 is blown out into the water 2 from the end immersed in the water 2 of the suction pipe 3. However, since the air diffuser 13 shown in FIG. 5 is attached to the end of the suction pipe 3, the mist-containing air blown out into the water 2 is diffused in the water 2 by the air diffuser 13. Here, a plurality of comb-shaped teeth 13a are formed on the cylinder 13A of the air diffuser 13, and vertically elongated gaps δ are formed between these teeth 13a. Therefore, a large number of fine bubbles are generated when the mist-containing air passes through these gaps δ. For this reason, the paint mist contained in the mist-containing air is efficiently taken into the water 2 and reliably separated from the air.

[0045] Next, the water 2 containing air (bubbles) around the whisking device 13 passes through the scrubber 14 as the gas-liquid separation means shown in FIGS. 7 to 9, and the air is separated and removed from the water 2. That is, the water 2 containing air (bubbles) around the whisking device 13 flows into the scrubber 14 from the inlets 14a opening above and below the vertical wall 14A of the scrubber 14 as shown by the arrows in FIG. 8, respectively, flows through the first flow path F1, then merges and flows into the second flow path F2 from the communication port 14b. Then, the water 2 containing air (bubbles) flowing into the second flow path F2 heads upward while swirling in the second flow path F2, changes the flow direction, flows into the third flow path F3 from the communication port 14c, and finally flows out from the outlet 14d into the first chamber 10a of the mist treatment tank 10. In the process where the water 2 containing air flows through the first flow path F1, the second flow path F2, and the third flow path F3 in the scrubber 14 while changing the direction, since the inertial force acting on the water is greater than the inertial force acting on the air due to the difference in specific gravity between the air and the water, the air contained in the water is separated and removed. The water 2 (water containing paint mist) from which the air has been removed and flows out from the outlet 14d into the first chamber 10a of the mist treatment tank 10 flows from the first chamber 10a to the second chamber 10b through the opening 10B.

[0046] As described above, the air separated and removed from the water 2 by the scrubber 14 is sucked into the exhaust blower 40 from the decompression space S of the mist treatment tank 10 through the filter 19 and the intake pipe 5 as shown by the arrows in FIGS. 1 to 3 and FIG. 10, is pressurized by the exhaust blower 40, then discharged into the exhaust pipe 6, flows upward through the exhaust pipe 6, and is finally released into the atmosphere. Since this air is clean and contains neither paint mist nor water droplets, the paint mist and water droplets do not adhere to the exhaust blower 40, and the surrounding environment is not polluted. Therefore, regular cleaning of the exhaust blower 40 is not required, maintenance-free is realized, and problems such as harming human health do not occur.

[0047] On the other hand, the coating mist separated from the air by the foaming device 13 or the like and taken into the water 2 forms a layer on the water 2 and floats because its specific gravity is smaller than that of the water 2, and aggregates to stay as sludge 4. Note that the coating mist may be aggregated by adding a flocculant containing sodium aluminate or the like to obtain the sludge 4.

[0048] The sludge 4 staying on the water 2 in the second chamber 10b of the mist treatment tank 10 flows into the recovery container 15 from the peripheral edge of the opening, and the flowed-in sludge 4 is pumped together with the water 2 from the pipe 16 to the mist recovery tank 20 by the pump 17. Then, the sludge 4 pumped to the mist recovery tank 20 forms a layer on the water 2 and stays inside the mist recovery tank 20.

[0049] The sludge 4 staying in a layer on the water 2 inside the mist recovery tank 20 flows into the recovery container 21 from the peripheral edge of the opening of the recovery container 21 and is recovered, and is pumped from the pipe 22 to the sludge recovery tank 30 by the pump 23. Here, as shown in FIGS. 1 and 2, if a detachable tank 31 is installed in the sludge recovery tank 30, when the sludge 4 accumulates in the tank 31, the tank 31 can be removed from the sludge recovery tank 30, and the sludge 4 accumulated in the tank 31 can be discarded at a predetermined disposal site, so that the disposal of the sludge 4 is facilitated. Alternatively, although not shown, in addition to installing the tank 31, a movable member for scraping out the sludge 4 staying in the upper part of the sludge recovery tank 30 to the outside of the sludge recovery tank 30 may be installed, and the sludge 4 staying in the sludge recovery tank 30 may be configured to be scraped out to the outside by the movable member.

[0050] Also, the water 2 accumulated in the mist recovery tank 20 is returned from the pipe 25 to the mist treatment tank 10 by the pump 24 as shown in FIG. 10, so that the water 2 circulates between the mist treatment tank 10 and the mist recovery tank 20 and does not flow out to the outside. For this reason, operations such as discarding the water 2 or replacing it with new water 2 are unnecessary, and effective utilization of resources and labor saving can be achieved. Furthermore, treatment steps such as purification treatment of the drainage are also unnecessary.

[0051] Note that the sludge 4 sent from the mist recovery tank 20 to the sludge recovery tank 30 through the pipe 22 also contains moisture. Therefore, as shown in FIG. 10, a return pipe 32 for returning water 2 from the sludge recovery tank 30 to the mist recovery tank 20 is installed. The moisture in the sludge recovery tank 30 is returned to the mist recovery tank 20 by this return pipe 32.

[0052] As described above, in the wet mist collection device 1 according to the present invention, the mist treatment tank 10, the mist recovery tank 20, and the sludge recovery tank 30 are provided independently of the painting chamber (painting booth) 100 where the painting mist is generated. Therefore, the height of the wet mist collection device 1 can be kept low and its miniaturization can be achieved.

[0053] In addition, since the sludge 4 of the painting mist is recovered in two stages in the mist treatment tank 10 and the mist recovery tank 20, the recovery efficiency of the sludge 4 is increased, and as a result, the collection efficiency of the painting mist of the wet mist collection device 1 is increased.

[0054] Furthermore, the painting mist is separated from the air (mist-containing air) and efficiently taken into the water 2 by bubbling the air containing the painting mist generated in the painting chamber (painting booth) 100 in the water 2 by the bubbler 13 in the mist treatment tank 10. Therefore, the collection efficiency of the painting mist of the wet mist collection device 1 is increased.

[0055] Note that the present invention has been described above by taking the case of collecting painting mist as an example. However, the wet mist collection device according to the present invention is not limited to being applied to the collection of painting mist, and can be similarly applied to the collection of any other mist.

[0056] In addition, the present invention is not limited to being applied to the above-described embodiments, and various modifications are possible within the scope of the technical idea described in the claims, the specification, and the drawings.

Claims

1. A mist treatment tank that forms a reduced-pressure space in which water is stored, sucks air containing mist, takes in the mist contained in the air into the water, and separates the mist from the air; A mist recovery tank whose interior is maintained at atmospheric pressure and that recovers the mist separated from the air in the mist treatment tank; A sludge recovery tank that recovers the mist recovered in the mist recovery tank as sludge; An exhaust blower connected to the mist treatment tank; and The mist treatment tank is provided with a pump that pumps a part of the water containing the mist separated from the air in the mist treatment tank to the mist recovery tank. A wet mist collection device characterized by this.

2. A mist treatment tank that forms a reduced-pressure space in which water is stored, sucks air containing mist, takes in the mist contained in the air into the water, and separates the mist from the air; A mist recovery tank whose interior is maintained at atmospheric pressure and that recovers the mist separated from the air in the mist treatment tank; A sludge recovery tank that recovers the mist recovered in the mist recovery tank as sludge; An exhaust blower connected to the mist treatment tank; and The mist recovery tank is provided with a pump that pumps the sludge of the mist to the sludge recovery tank. A wet mist collection device characterized by this.

3. A mist treatment tank that forms a reduced-pressure space in which water is stored, sucks air containing mist, takes in the mist contained in the air into the water, and separates the mist from the air; A mist recovery tank whose interior is maintained at atmospheric pressure and that recovers the mist separated from the air in the mist treatment tank; A sludge recovery tank that recovers the mist recovered in the mist recovery tank as sludge; An exhaust blower connected to the mist treatment tank; and The wet mist collection device is characterized in that the mist treatment tank is provided with comb-shaped bubbling means for bubbling air containing mist in water.

4. The wet mist collection device according to any one of claims 1 to 3, wherein the mist recovery tank is provided with a pump for returning the water to the mist treatment tank.

5. The wet mist collection device according to any one of claims 1 to 4, wherein the mist treatment tank is provided with gas-liquid separation means for separating and removing air from water containing air.

6. The wet mist collection device according to any one of claims 1 to 5, wherein the sludge recovery tank is detachably provided with a tank for discharging the recovered sludge to the outside of the sludge recovery tank.

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