Gas treatment device

Abstract

To provide an inexpensive gas treatment device which can prevent coating particles adhering to a spiral-plate-like collection member from peeling off and being discharged to the outside.SOLUTION: A gas treatment device 101 is for treating gas Ga containing coating particles M, and includes a collection member 22 formed like a spiral plate and having a spiral flow channel extending from an inflow port located radially outward to an outflow port located in a central side, and a collection part 30 which collects the coating particles M contained in the discharge gas Gb outflowing from the collection member 22.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a gas treatment device. [Background technology]

[0002] Patent Document 1 below discloses a conventional paint recovery device. This paint recovery device includes a cyclone vessel having a large-diameter cylindrical portion, a small-diameter cylindrical portion, and a conical cylindrical portion between the large-diameter cylindrical portion and the small-diameter cylindrical portion. Paint particles contained in air flow into the cyclone vessel through an intake pipe in the large-diameter cylindrical portion and then swirl inside the cyclone vessel, flowing from the large-diameter cylindrical portion toward a recovery pipe in the small-diameter cylindrical portion. The paint particles are centrifuged by the swirling air flow, and the centrifuged paint particles are recovered from the cyclone vessel through the recovery pipe. The centrifuged air also flows in the opposite direction, from the small-diameter cylindrical portion of the cyclone vessel toward an exhaust pipe in the large-diameter cylindrical portion, and then exhausted from the cyclone vessel through the exhaust pipe.

[0003] Patent Document 2 below discloses a spiral electrode type air purifier. This spiral electrode type air purifier is equipped with a spiral dust collection electrode made of a thin metal plate wound in a spiral shape with a certain gap between them. The spiral dust collection electrode has an air flow path (swirl flow path) formed in a spiral shape from the outer periphery toward the axial center. A negative voltage is applied to this spiral dust collection electrode. As air containing positively charged microparticles flows through the spiral air flow path of the spiral dust collection electrode toward the axial center, it is electrostatically adsorbed to the surface of the spiral dust collection electrode by electrostatic force and removed. The air from which the microparticles have been removed and which flows into the axial center is discharged from an air outlet. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-202248 [Patent Document 2] Japanese Utility Model Application Publication No. 7-13447 Summary of the Invention [Problem to be solved by the invention]

[0005] In the paint recovery device of Patent Document 1, air that flows into the cyclone container swirls from the large-diameter cylindrical portion to the small-diameter cylindrical portion, then reverses direction at the small-diameter cylindrical portion and flows back to the large-diameter cylindrical portion. This paint recovery device has a problem of high pressure loss due to the structure that involves a reverse flow of air inside the cyclone container.

[0006] To address this issue, the spiral dust collecting electrode of Patent Document 2 can be used. With this spiral dust collecting electrode, when air containing paint particles flows through a spiral air flow path toward the axial center, the paint particles can be electrically attached to the electrode surface by utilizing electrostatic force, making it possible to collect them. The use of a spiral plate-shaped spiral dust collecting electrode can reduce pressure loss compared to the cyclone vessel of Patent Document 1.

[0007] However, a collection structure that electrically attaches paint particles to a collection member (a spiral collection electrode) to collect them is disadvantageous in that it requires an expensive high-voltage circuit to generate high voltage, resulting in high equipment costs. Therefore, a collection member that employs only the shape of a spiral collection electrode and physically attaches paint particles to the surface of a spiral plate-shaped collection member to collect them can be used. Such a collection member does not require an expensive high-voltage circuit, which is effective in keeping equipment costs low. On the other hand, a structure that physically collects paint particles using a spiral plate-shaped collection member tends to cause paint particles that once adhere to the surface of the collection member to peel off and re-scatter. In particular, when non-adhesive or low-adhesive paint particles are collected using a spiral plate-shaped collection member, the paint particles may peel off from the surface of the collection member, re-scatter, and be discharged to the outside.

[0008] The present invention has been made in consideration of such problems, and aims to provide an inexpensive gas treatment device that can prevent paint particles adhering to a spiral plate-shaped collection member from peeling off and being discharged to the outside. [Means for solving the problem]

[0009] One aspect of the present invention is A gas treatment device for treating a gas containing paint particles, a collecting member formed in a spiral plate shape, having a swirling flow path extending from an inlet on the outer periphery side in the radial direction to an outlet on the center side (23b), and a flow path wall surface that partitions the swirling flow path, and which physically adheres the paint particles to the flow path wall surface to collect them; a collection section that collects the paint particles contained in the exhaust gas that flows out from the outlet of the collection member; a gas treatment device comprising: is located. [Effects of the Invention]

[0010] In the gas treatment device of the above-described embodiment, when gas containing paint particles passes through the swirling flow path of the spiral plate-shaped trapping member, the paint particles physically adhere to the flow path wall surface of the trapping member and are thereby captured. Furthermore, paint particles that once adhere to the flow path wall surface of the trapping member and then peel off and flow out through the outlet are captured by the capture unit. Therefore, the capture unit can prevent paint particles that peel off from the flow path wall surface of the trapping member from being discharged to the outside. In particular, when non-adhesive or low-adhesive paint particles are captured by the spiral plate-shaped trapping member, paint particles that once adhere to the flow path wall surface of the trapping member are prone to peeling off and re-scattering. Therefore, providing a capture unit is particularly effective in such cases. Furthermore, because the trapping member that captures paint particles is designed to physically adhere paint particles to the flow path wall surface, it is effective in reducing the costs required for the trapping member and its peripheral equipment compared to, for example, a structure that electrically captures paint particles.

[0011] According to the above-described aspect, it is possible to provide an inexpensive gas treatment device that can prevent paint particles adhering to the spiral plate-shaped collection member from peeling off and being discharged to the outside. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a side view showing the overall structure of a paint booth according to a first embodiment. [Figure 2] FIG. 2 is a side view of the gas treatment device of the first embodiment. [Figure 3] 3 is a plan view of the collection unit of the gas treatment device of FIG. 2, seen from above. FIG. [Figure 4] FIG. 4 is a perspective view of the internal structure of the collection unit of FIG. 3, seen obliquely from above. [Figure 5] FIG. 5 is a radial cross-sectional view of the collection member in FIG. 4. [Figure 6] 6 is a cross-sectional view showing the collection member of FIG. 5 in a state where paint particles are collected. [Figure 7] FIG. 4 is a diagram showing the particle size distribution of paint particles. [Figure 8] 6 is a perspective view showing the collection member of FIG. 5 in a flattened, unfolded state. FIG. [Figure 9] 4 is a graph showing the correlation between the number of turns of the collection member and the collection efficiency and pressure loss. [Figure 10] FIG. 10 is a diagram for explaining the structural features of a collection member that belongs to the high performance region of the graph in FIG. [Figure 11] FIG. 3 is a plan view of the first unit of the gas treatment device of FIG. 2 as viewed from above. [Figure 12] FIG. 12 is a perspective view showing the first unit of FIG. 11 in an exploded state. [Figure 13] 13 is a diagram schematically showing a state in which a swirling flow of exhaust gas is formed in the recovery processing space of the first unit of FIG. 12. FIG. [Figure 14] 3 is a perspective view showing a state in which the collection box is pulled out from the case of the second unit of the gas treatment device of FIG. 2. FIG. [Figure 15] FIG. 10 is a front view of a gas treatment device according to a second embodiment. [Figure 16] FIG. 16 is a side view of the gas treatment device of FIG. [Figure 17] FIG. 10 is a front view of a gas treatment device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Preferred embodiments of each of the above aspects are described below.

[0014] In the gas treatment device of the above aspect, it is preferable that the recovery section includes a first unit that houses a baffle member for forming a stagnation area for the exhaust gas, and a second unit that houses a filter member that captures the paint particles that have passed through the baffle member.

[0015] In this gas treatment device, a stagnation area for exhaust gas flowing out from the outlet of the collection member is formed by the baffle member in the first unit. As the exhaust gas stagnates and its flow velocity decreases, paint particles contained in the exhaust gas tend to accumulate in the stagnation area due to their own weight. Paint particles that pass through the baffle member are collected by the filter member of the second unit. By providing the baffle member upstream of the filter member, the dust collection load of the filter member can be reduced. In addition, clogging of the filter member can be prevented, extending the life of the filter member. As a result, resource conservation is achieved and running costs can be kept low.

[0016] In the gas treatment device of the above-mentioned aspect, the first unit preferably comprises an upper plate portion having an inlet opening through which the exhaust gas flows while swirling, a lower plate portion having an outlet opening communicating with the second unit, and a frame portion between the upper plate portion and the lower plate portion, and the baffle member is interposed in the recovery treatment space of the frame portion, and a plurality of the baffle members are preferably arranged radially around the outlet opening.

[0017] In this gas treatment device, exhaust gas in the first unit swirls through the inlet opening of the upper plate and flows into the collection and treatment space in the frame. After passing through multiple baffle members, it flows out through the outlet opening of the lower plate to the second unit. During this process, flaking particles (paint particles detached from the collection member) in the exhaust gas are captured between the baffle members due to inertia. Furthermore, by arranging multiple baffle members radially around the outlet opening of the lower plate, the multiple baffle members can form a stagnation area for the swirling flow of exhaust gas, preventing the captured flaking particles from being re-entrained and from flowing into the second unit.

[0018] In the gas treatment device of the above aspect, it is preferable that the baffle member also serves as a reinforcing member for reinforcing the second unit.

[0019] According to this gas treatment device, the baffle member serves both the function of forming a stagnation area for exhaust gas and the function of reinforcing the first unit, making it possible to reduce the number of parts compared to a structure in which each function is realized by a dedicated member.

[0020] In the gas treatment device of the above aspect, the collection member is preferably configured so that the swirl diameter of the swirl flow path gradually decreases from the inlet to the outlet.

[0021] According to this gas treatment device, the swirl diameter of the swirl flow path of the collection member gradually decreases from the inlet gap at the inlet to the outlet gap at the outlet, thereby gradually increasing the centrifugal force acting on the paint particles toward the outlet gap. This centrifugal force is used to adhere the paint particles to the flow path wall of the collection member and capture them, thereby improving the paint particle capture efficiency. Furthermore, by selectively capturing coarse particles near the inlet gap at the inlet of the swirl flow path using a relatively weak centrifugal force, it is possible to prevent paint particles of a wide range of particle diameters from accumulating and clogging near the inlet gap. Meanwhile, near the outlet gap at the outlet of the swirl flow path, it is possible to reliably capture fine particles that were not captured upstream using a strong centrifugal force. This prevents high pressure loss due to the accumulation of paint particles. Furthermore, the reduced pressure loss allows for an increased gas processing volume.

[0022] In the gas treatment device of the above aspect, it is preferable that a plurality of the collection members are stacked concentrically in the vertical direction, and that the outlet of the upper collection member is configured to communicate with the swirling flow path of the lower collection member.

[0023] According to this gas treatment device, the gas containing paint particles can be treated in multiple stages using multiple collection members, thereby making it possible to increase the efficiency of collecting paint particles.

[0024] In the gas treatment device of the above aspect, it is preferable that the number of turns of the spiral of the upstream collection member is greater than the number of turns of the spiral of the downstream collection member.

[0025] According to this gas treatment device, it is possible to increase the paint particle collection efficiency in the upstream collection member while suppressing pressure loss in the downstream collection member.

[0026] Hereinafter, an embodiment of a gas treatment device provided in a paint booth will be described with reference to the drawings.

[0027] In the drawings for explaining this embodiment, unless otherwise specified, the first direction, which is the vertical direction of the gas treatment device, is indicated by arrow X, the second direction, which is the horizontal direction, is indicated by arrow Y, and the third direction, which is the up-down direction (height direction), is indicated by arrow Z. Furthermore, the radial direction of the collection member constituting the gas treatment device is indicated by arrow A, the circumferential direction of the collection member is indicated by arrow B, and the direction of the winding axis of the collection member is indicated by arrow C.

[0028] (Embodiment 1) 1. Overall structure of paint booth 1 As shown in Figure 1, a paint booth 1 according to the first embodiment is used to spray paint a workpiece W, such as an automobile body. The paint booth 1 is provided with a paint chamber 2, an air supply chamber 4, and a baffle chamber 7. The air supply chamber 4 is located above the paint chamber 2, and the baffle chamber 7 is located below the paint chamber 2.

[0029] The coating chamber 2 has a coating treatment space into which the workpiece W can be introduced and removed by a transport device 3. The coating chamber 2 is provided with a plurality of coating nozzles 6 for spraying paint N from the side toward the workpiece W introduced into the coating treatment space. The paint N sprayed from each coating nozzle 6 is applied to the workpiece W by compressed air ejected from the coating nozzle 6.

[0030] The air supply chamber 4 is provided with an air conditioning unit (not shown) for producing temperature- and humidity-controlled air G, and an air supply fan 5 for drawing in and discharging this air G. The air G discharged from the air supply fan 5 forms a downward current that flows downward toward the coating chamber 2. Therefore, paint N that has not been applied to the workpiece W in the coating chamber 2 flows downward as atomized paint particles M along the downward current of air G. The paint particles M are liquid molecules of the paint N (paint mist) that float in the air G. In this embodiment, these paint particles M are the objects to be collected.

[0031] A partition wall 8, which constitutes the floor 2a of the coating chamber 2, is provided between the coating chamber 2 and the baffle chamber 7. The partition wall 8 has communication holes 8a that allow paint particles M produced in the coating chamber 2 to flow into the baffle chamber 7. Therefore, the baffle chamber 7 communicates with the coating chamber 2 only through the communication holes 8a that penetrate the partition wall 8. A gas processing device 101 is disposed in the baffle chamber 7 below the floor of the coating chamber 2. The gas processing device 101 is connected to a connecting portion 9a and is thereby connected to an exhaust duct 9 via an exhaust pipe 9b. A damper 9c for adjusting the air volume is preferably provided inside the exhaust pipe 9b.

[0032] In this embodiment, when the pressure in the exhaust duct 9 is P1, the pressure inside the gas treatment device 101 is P2, the pressure in the baffle chamber 7 is P3, and the pressure in the coating chamber 2 is P4, the pressure balance between these is expressed as P4>P3>P2>P1. According to this pressure balance, the gas Ga containing the paint particles M flows from the coating chamber 2 into the baffle chamber 7, is treated in the gas treatment device 101, and then is exhausted to the outside through the exhaust duct 9.

[0033] 2. Overall structure of gas treatment device 101 2, the gas treatment device 101 of the first embodiment is for treating a gas Ga containing paint particles M. The gas treatment device 101 is roughly divided into an air supply duct 10, a collection unit 20, a recovery unit 30, and a transport vehicle 60.

[0034] The transporting cart 60 includes a cart body 61 on which the integrated air intake duct 10, the collection unit 20, and the recovery unit 30 are placed, a plurality of wheels 62 that support the cart body 61 so that it can move, and a handle 63 that is provided on the cart body 61 so that it can be held by an operator. The operator can carry the transporting cart 60 into or out of the baffle chamber 7 (see FIG. 1) while holding the handle 63.

[0035] Air supply duct 10 has a frame shape with a rectangular cross section when viewed from third direction Z. Air supply duct 10 has an internal space 10a defined by the frame shape. Collector 20 is disposed below air supply duct 10.

[0036] The collection unit 20 includes a case 21 having a frame shape with a rectangular cross section when viewed from the third direction Z, and a plurality of collection members 22 housed in an internal space 21a of the case 21. The collection unit 20 is integrated with the air intake duct 10. When the collection unit 20 is integrated with the air intake duct 10, the internal space 21a of the case 21 communicates with the internal space 10a of the air intake duct 10. The collection unit 20 allows the gas Ga to flow into the internal space 21a of the case 21 through the internal space 10a of the air intake duct 10. At this time, paint particles M contained in the gas Ga are collected by the collection members 22.

[0037] The recovery section 30 has the function of recovering paint particles M contained in the exhaust gas Gb that has flowed out from the collection member 22. This recovery section 30 includes a first unit 40 and a second unit 50. The first unit 40 is disposed below the collection section 20, and the second unit 50 is disposed further below the first unit 40. A baffle member 46, which will be described later, is housed in the internal space 41a of the case 41 of the first unit 40. Therefore, detached particles (paint particles M that have detached from the collection member 22) in the exhaust gas Gb after treatment in the collection section 20 are captured by the baffle member 46. The exhaust gas Gc after treatment in the first unit 40 flows into the second unit 50. A filter member 54 is housed in the recovery treatment space 52a of the second unit 50. The filter member 54 is a filter member that can prevent fine particles in the paint particles M from passing through. Therefore, the paint particles M contained in the exhaust gas Gc are collected by adhering to the surface of the filter member 54. The exhaust gas Gd after being processed in the second unit 50 flows toward the exhaust duct 9 (see FIG. 1).

[0038] 3, case 21 has two internal spaces 21a separated by partition wall 21b. The upper part of each internal space 21a is covered with upper plate 26, except for cutout opening 26a that communicates with internal space 10a of air supply duct 10. Therefore, internal space 10a of air supply duct 10 communicates with internal space 21a through cutout opening 26a.

[0039] 2-1. Structure of the collection member 22 3 and 4, in this embodiment, eight collection members 22 are housed in the case 21. The collection members 22 are formed in a spiral plate shape and are arranged vertically so that the winding axis direction C of the collection members 22 is aligned with the third direction Z. The collection members 22 have swirling flow paths 23 extending from an inlet 23a on the outer periphery side in the radial direction A to an outlet 23b on the center side. Gas Ga containing paint particles M flows into the internal space 21a through the cutout opening 26a of the upper plate 26 (see FIG. 3) and then flows into the swirling flow paths 23 from the inlet 23a. The gas Ga then forms a spiral swirling flow E in the swirling flow paths 23. Arranging the collection members 22 vertically is effective in collecting paint particles M that have low viscosity and are prone to crumbling. Such collection members 22 are also called "spiral cyclones."

[0040] In each internal space 21a, two collection members 22 are stacked concentrically (so that the winding axis direction C coincides) in two upper and lower stages in the third direction Z via an intermediate plate 27, and are configured so that the outlet 23b of the upper collection member 22 communicates with the swirling flow path 23 of the lower collection member 22. In each stage, one collection member 22 is juxtaposed to another collection member 22, and the two juxtaposed collection members 22 are arranged so that one forms a clockwise spiral and the other forms a counterclockwise spiral.

[0041] The two trapping members 22 arranged in the upper tier are covered at their tops with an upper plate 26. The two trapping members 22 arranged in the lower tier are covered at their bottoms with a lower plate 28. The lower plate 28 is provided with a circular outlet opening 28a that communicates with the central space 23c of the swirling flow path 23 of the trapping member 22 in the lower tier. The intermediate plate 27 is provided with a connecting opening 27a that connects the swirling flow path 23 of the upper trapping member 22 with the swirling flow path 23 of the lower trapping member 22. Therefore, the outlet 23b of the upper trapping member 22 communicates with the swirling flow path 23 of the lower trapping member 22. Gas Ga flows in through the inlet 23a of the lower trapping member 22, while gas Ga processed by the upper trapping member 22 flows into the swirling flow path 23 of the lower trapping member 22 through the connecting opening 27a of the intermediate plate 27. The intermediate plate 27 serves to reinforce the collection member 22 and to rectify the flow of the gas Ga.

[0042] Gas Ga (see FIG. 2) that flows in through inlet 23a of upper collection member 22 swirls in swirling flow path 23 of that collection member 22, and then swirls further in swirling flow path 23 of the lower collection member 22, before being discharged from central space 23c through outlet 23b of that collection member 22. As paint particles M flow through swirling flow path 23, some of them adhere to and are collected on flow path wall surface 24 (the surface that defines swirling flow path 23), which is the surface of collection member 22, and exhaust gas Gb (see FIG. 2) after collection turns approximately 90° in central space 23c of collection member 22 and flows downward through outlet opening 28a of lower plate 28.

[0043] The collection section 20 is preferably configured so that the number of turns of the spiral of the upstream collection member 22 exceeds the number of turns of the spiral of the downstream collection member 22. This configuration makes it possible to increase the efficiency of collection of paint particles M in the upstream collection member 22 while suppressing pressure loss in the downstream collection member 22.

[0044] The number of collection members 22 housed in case 21 is not limited to eight, and the arrangement of collection members 22 is not limited to a two-tiered stacked arrangement. For example, one or more collection members 22 may be arranged in a single tier, or may be stacked in three or more tiers.

[0045] As shown in Figure 5, collection member 22 is spirally formed around imaginary central axis L from outer peripheral end 22a to inner peripheral end 22b. Collection member 22 is formed by rolling a plate-like member with a constant width in the winding axis direction C into a spiral. In swirling flow path 23 of collection member 22, inlet 23a on the outer peripheral end 22a side has an inlet gap, and outlet 23b on the inner peripheral end 22b side has an outlet gap. A central space 23c is provided inward in the radial direction A from outlet 23b of collection member 22, and this central space 23c communicates with outlet opening 28a of lower plate 28. Central space 23c is formed so that its shape when viewed in the winding axis direction C is generally circular.

[0046] The collection member 22 is configured so that the swirl radius r (position in the radial direction A from the central axis L) of the outer edge of its swirl flow path 23 gradually decreases from the inlet 23a to the outlet 23b. The swirl flow path 23 has a flow path width indicated by the swirl spacing d in the radial direction A. When gas Ga containing paint particles M flows through the swirl flow path 23 in the circumferential direction B from the inlet 23a to the outlet 23b, a centrifugal force acts on the paint particles M due to the swirling effect of the swirling flow E (see FIG. 4). If the flow velocity of the paint particles M is v and the centrifugal force acting on the paint particles M is F, the centrifugal force F is expressed by the following equation (1). According to equation (1), the centrifugal force F increases as the swirl radius r gradually decreases from the inlet 23a to the outlet 23b. The centrifugal force F at this time is used to collect the paint particles M. Specifically, as shown in Figure 6, paint particles M can be physically attached to the flow path wall surface 24 (the surface that defines the swirling flow path 23), which is the thickness-wise surface of the collection member 22, and collected as paint N.

[0047] F=v 2 / r ···(1)

[0048] According to equation (1), the centrifugal force F acting on the paint particles M increases as the swirl radius r gradually decreases from the inlet 23a to the outlet 23b of the swirl flow path 23. For example, if the flow velocity v of the paint particles M is constant and the swirl radius r at the outlet 23b is half that on the inlet 23a side, when the paint particles M swirl from the inlet 23a to the outlet 23b, the centrifugal force F increases to twice that on the inlet 23a side.

[0049] When the particle size distribution of the paint particles M is, for example, as shown in Figure 6, coarse particles with a relatively large particle size can be collected with a relatively weak centrifugal force F, while fine particles with a relatively small particle size require a strong centrifugal force F to be collected. If the centrifugal force F is increased throughout the swirl flow path 23 in order to collect fine particles, paint will easily accumulate and clog near the inlet 23a of the swirl flow path 23 regardless of particle size. This increases pressure loss. However, if the centrifugal force F is reduced throughout the swirl flow path 23 in order to avoid paint accumulation near the inlet 23a of the swirl flow path 23, the collection efficiency of the paint particles M will decrease.

[0050] Therefore, the collection member 22 of this embodiment is designed so that the centrifugal force F acting on the paint particles M increases from the inlet 23a of the swirl flow path 23 toward the outlet 23b. This design allows the centrifugal force F to be weakest near the inlet 23a of the swirl flow path 23 and strongest near the outlet 23b of the swirl flow path 23. As a result, by selectively capturing coarse particles near the inlet 23a of the swirl flow path 23 using a relatively weak centrifugal force F, it is possible to prevent paint particles M with a wide range of particle diameters from accumulating and clogging the swirl flow path 23. Meanwhile, near the outlet 23b of the swirl flow path 23, it is possible to reliably capture fine particles that were not captured upstream using a strong centrifugal force F. This prevents high pressure loss due to the accumulation of paint particles M. Furthermore, the reduced pressure loss allows for an increased airflow rate for processing the paint particles M.

[0051] As shown in FIG. 7 , the collection member 22 of this embodiment preferably has an uneven portion 25 on one of the flow path wall surfaces 24 on both sides that define the swirling flow path 23 (i.e., on both sides of the collection member 22). The uneven portion 25 is a wave-like portion formed to partially interrupt the flow of the paint particles M, and is configured so that both the crest line and the bottom line of the wave extend in the winding axis direction C. By providing the uneven portion 25 on the flow path wall surface 24 of the collection member 22, immediately after the start of use, the convex portions of the uneven portion 25 can interrupt the flow of some of the paint particles M while the paint particles M can be deposited and collected in the concave portions. Thereafter, as the collection of the paint particles M progresses, the uneven portion 25 becomes a generally flat surface, making it possible to maintain a constant pressure loss.

[0052] To manufacture the collection member 22, for example, single-sided corrugated cardboard, which is an incinerable material, can be used. The collection member 22 can be manufactured by rolling up the unfolded single-sided corrugated cardboard into a spiral shape. In this case, the corrugated shape already provided on one side of the single-sided corrugated cardboard can be used as the uneven portion 25. Using single-sided corrugated cardboard can keep the cost required for the collection member 22 low. If necessary, uneven portions 25 may be provided on the flow path wall surfaces 24 on both sides of the collection member 22.

[0053] Note that, instead of the corrugated uneven portion 25, for example, an uneven portion consisting of a plurality of protrusions can be employed. Furthermore, instead of or in addition to using the corrugated uneven portion 25, it is also possible to employ a structure that has been subjected to a coating treatment with a material that has a high affinity with the paint particles M. Furthermore, when the efficiency of collecting paint particles M is at a desired level, the flow path wall surface 24 of the collecting member 22 may be a flat surface without any uneven portions.

[0054] 2-2. Performance evaluation of the collection member 22 The inventors conducted a performance evaluation of the actual use of the collection member 22. In this performance evaluation, the collection efficiency of the paint particles M and the pressure loss were evaluated when predetermined structural parameters were appropriately changed. The structural parameters used in this evaluation included the number of turns of the collection member 22, the spiral spacing d of the collection member 22, the opening diameter D1 of the central space 23c of the swirling flow path 23 of the collection member 22 (assuming that the shape of the central space 23c when viewed from the winding axis direction C is circular for convenience), and the opening diameter D2 of the outlet opening 28a of the lower plate 28 (see FIG. 5).

[0055] As shown in the graph of FIG. 9, the results of the performance evaluation confirmed that the efficiency of collecting paint particles M increases as the number of turns of the collection member 22 increases. This is because the greater the number of turns of the collection member 22, the greater the collection area for collecting paint particles M, i.e., the longer the length of the swirl flow path 23. Similarly, the results of the performance evaluation confirmed that the pressure loss decreases as the number of turns of the collection member 22 decreases. This is because the fewer the number of turns of the collection member 22, the less resistance the paint particles M experience from the collection member 22. Based on FIG. 9, when the number of turns of the collection member 22 is set within a predetermined range, it is possible to obtain a high-performance region R that can achieve both improved collection efficiency of paint particles M and reduced pressure loss by optimizing the structural parameters.

[0056] Here, the structural features of the collection member 22 belonging to the high performance region R in Fig. 9 will be described with reference to Fig. 5 and Fig. 10. Note that Fig. 10 illustrates three collection members 22 (first collection member 22A, second collection member 22B, and third collection member 22C) belonging to the high performance region R. The number of turns of these three collection members 22A, 22B, and 22C is the same.

[0057] As shown in Fig. 10, first collection member 22A is configured so that the spiral spacing d (see Fig. 5) is constant from inlet 23a to outlet 23b of swirl flow path 23. This first collection member 22A is also configured so that opening diameter D1 (see Fig. 3) of central space 23c of swirl flow path 23 is approximately equal to opening diameter D2 (see Fig. 3) of outlet opening 28a. That is, when first collection member 22A is viewed from the winding axis direction C, flow path wall surface 24 defining central space 23c extends so as to overlap opening edge 28b (see Fig. 5) of outlet opening 28a. The correlation between collection efficiency and pressure loss when this first collection member 22A is used is shown by the "○ plot" in Fig. 10.

[0058] The second collection member 22B is configured so that the spiral spacing d in the radial direction A of the swirling passage 23 gradually decreases from the inlet 23a to the outlet 23b. Similar to the first collection member 22A, the second collection member 22B is configured so that the opening diameter D1 of the central space 23c of the swirling passage 23 roughly matches the opening diameter D2 of the outlet opening 28a. The correlation between the collection efficiency and pressure loss when the second collection member 22B is used is shown by the "◎ plot" in Figure 10. Of the three collection members 22A, 22B, and 22C, the second collection member 22B is most effective in achieving both improved collection efficiency and reduced pressure loss.

[0059] When the second collection member 22B is used, the collection efficiency of the paint particles M is higher than when the first collection member 22A is used. This is because the swirl interval d of the swirl flow path 23 is gradually reduced from the inlet 23a to the outlet 23b. In other words, by gradually reducing the swirl interval d from the inlet 23a to the outlet 23b, the flow velocity v of the paint particles M increases as they move from the inlet 23a to the outlet 23b. As the flow velocity increases, the effect of increasing the centrifugal force F acting on the paint particles M increases. As a result, the collection efficiency of the paint particles M can be further improved.

[0060] For example, when formula (1) is applied, if the vortex spacing d at the outlet 23b is half that at the inlet 23a, the flow velocity v of the paint particles M doubles, and therefore, when the paint particles M swirl from the inlet 23a to the outlet 23b, the centrifugal force F increases to eight times that at the inlet 23a. As a result, it is presumed that the collection efficiency of the paint particles M increases.

[0061] When the second collection member 22B is used, the opening diameter D1 of the central space 23c of the swirl flow path 23 is made to roughly coincide with the opening diameter D2 of the outlet opening 28a, thereby enabling a smooth flow from the central space 23c toward the outlet opening 28a, thereby further reducing pressure loss.

[0062] Similar to the first collection member 22A, the third collection member 22C is configured so that the swirl spacing d is constant from the inlet 23a to the outlet 23b of the swirling passage 23. The third collection member 22C is also configured so that the opening diameter D1 of the central space 23c of the swirling passage 23 is larger than the opening diameter D2 of the outlet opening 28a. The correlation between the collection efficiency and pressure loss when the third collection member 22C is used is shown by the "□ plot" in Figure 8.

[0063] When the third collection member 22C is used, the pressure loss increases compared to when the first collection member 22A is used. This is because the opening diameter D1 of the central space 23c is larger than the opening diameter D2 of the outflow opening 28a. It is presumed that, compared to when the opening diameter D1 is roughly the same as the opening diameter D2, a smooth flow from the central space 23c toward the outflow opening 28a is less likely to occur, resulting in a corresponding increase in pressure loss. To prevent excessive pressure loss, it is preferable to configure the inner circumferential end 22b (see FIG. 5) of the third collection member 22C so that it is closer to the opening edge 28b (see FIG. 5) of the outflow opening 28a to a position less than 10% of the opening diameter D2.

[0064] 2-3. Structure of the first unit 40 2, the first unit 40 includes a case 41 and two collection boxes 42 (see FIG. 11) housed in the case 41. The exhaust gas Gb flowing out from the collection section 20 flows into the collection processing space 45a of the first unit 40. The exhaust gas Gc passing through the collection processing space 45a of the first unit 40 flows into the second unit 50.

[0065] 11 and 12, each collection box 42 includes an upper plate portion 43 (see FIG. 12) having a plurality of inlet openings 43a through which the exhaust gas Gc flows while swirling, a lower plate portion 44 having a plurality of outlet openings 44a that communicate with the second unit 50, and a frame portion 45 between the upper plate portion 43 and the lower plate portion 44. The plurality of inlet openings 43a are the same in number as the plurality of outlet openings 44a, are circular and have the same diameter, and are formed at positions that overlap with each of the plurality of outlet openings 44a when viewed from the third direction Z.

[0066] The interior space of the frame portion 45 is divided into two recovery processing spaces 45a by a partition wall 45b. A plurality of baffle members 46 are interposed in each recovery processing space 45a. The plurality of baffle members 46 are arranged radially around the outlet opening 44a of the lower plate portion 44. In this embodiment, the plurality of baffle members 46 are plate-like members whose dimensions in the third direction Z are approximately constant and which extend radially outward from the edge of the outlet opening 44a of the lower plate portion 44.

[0067] The baffle member 46 has the function of forming a stagnation region S for the exhaust gas Gb that forms the swirling flow E in the recovery processing space 45a. Due to this function, the flow velocity of the exhaust gas Gb in the stagnation region S decreases due to interference with the baffle member 46. If the exhaust gas Gb contains paint particles M, some or all of these paint particles M will collide with the baffle member 46 and accumulate in the stagnation region S due to their own weight. This allows the paint particles M contained in the exhaust gas Gb that has flowed out of the collection section 20 to be recovered in the stagnation region S of the first unit 40.

[0068] Moreover, the baffle member 46 serves to reinforce the first unit 40 by increasing the rigidity of the collection box 42 itself. That is, the baffle member 46 of this embodiment is configured to perform both the function of forming the stagnation region S for the exhaust gas Gb and the function of reinforcing the first unit 40.

[0069] 2-4. Structure of the second unit 50 2, the second unit 50 includes a case 51 and a filter box 52 (see FIG. 14) housed in the case 51. The exhaust gas Gc flowing out from the first unit 40 flows into the recovery processing space 52a of the second unit 50. Then, the exhaust gas Gd passing through a filter member 54 provided in the recovery processing space 52a of the second unit 50 flows into the exhaust duct 9 (see FIG. 1).

[0070] As shown in FIG. 14 , the filter box 52 is housed in the case 51 so as to be slidable in the first direction X. The internal space of the filter box 52 is a collection and treatment space 52a for paint particles M contained in the exhaust gas Gc. A filter frame 53 holding a flat filter member 54 is disposed in an inclined state in the collection and treatment space 52a. The filter frame 53 is detachably attached to the filter box 52. Therefore, by pulling the filter box 52 out of the case 51 and removing the filter frame 53 together with the filter member 54, the filter member 54 can be replaced or cleaned without removing the collection section 20 or the first unit 40.

[0071] A plurality of inlet openings 51a are provided in the upper part of the case 51 for introducing the exhaust gas Gc into the recovery processing space 52a of the filter box 52. The plurality of inlet openings 51a are circular and have the same diameter as the plurality of outlet openings 44a on the first unit 40 side, and are formed at positions overlapping with the plurality of outlet openings 44a when viewed from the third direction Z. A housing opening 51b for housing the filter box 52 is provided on one side of the case 51 in the first direction X. An outlet opening 51c through which the exhaust gas Gd that has passed through the filter member 54 flows out is provided on the other side of the case 51 in the first direction X.

[0072] 3. Effects In the gas processing device 101, when gas Ga containing paint particles M passes through the swirling flow path 23 of the spiral plate-shaped trapping member 22, the paint particles M physically adhere to the flow path wall surface 24 of the trapping member 22 and are thereby captured. Furthermore, paint particles M that once adhere to the flow path wall surface 24 of the trapping member 22 and then peel off and flow out through the outlet 23b are captured by the collection unit 30. Therefore, the collection unit 30 can prevent the paint particles M that have peeled off from the flow path wall surface 24 of the trapping member 22 from being discharged to the outside. In particular, when non-adhesive paint particles M or paint particles M with low adhesiveness are captured by the spiral plate-shaped trapping member 22, the paint particles M that once adhered to the flow path wall surface 24 of the trapping member 22 are likely to peel off and re-scatter, so providing the collection unit 30 is particularly effective in such cases. Furthermore, since the collection member 22 that collects the paint particles M has a structure that physically adheres the paint particles to the flow path wall surface 24, it is effective in reducing the costs required for the collection member 22 and its peripheral equipment compared to, for example, a structure that electrically collects the paint particles M.

[0073] As described above, according to embodiment 1, it is possible to provide an inexpensive gas processing device 101 that can prevent paint particles M adhering to the spiral plate-shaped collection member 22 from peeling off and being discharged to the outside.

[0074] According to the gas treatment device 101, in the first unit 40, a stagnation region S for the exhaust gas Gb flowing out from the outlet 23b of the collection member 22 is formed by the baffle member 46. As the exhaust gas Gb stagnates and its flow velocity decreases, the paint particles M contained in the exhaust gas Gb tend to accumulate in the stagnation region S due to their own weight. The paint particles M that pass through the baffle member 46 are collected by the filter member 54 of the second unit 50. By providing the baffle member 46 upstream of the filter member 54, the dust collection load of the filter member 54 can be reduced. Furthermore, clogging of the filter member 54 can be suppressed, thereby extending the life of the filter member 54. As a result, resource conservation is achieved and running costs can be kept low.

[0075] According to the gas processing device 101, in the first unit 40, the exhaust gas Gb flows into the collection processing space 45a of the frame 45 while swirling through the inlet opening 43a of the upper plate 43, and after interfering with the plurality of baffle members 46, flows out through the outlet opening 44a of the lower plate 44 to the second unit 50. During this time, peeled particles (paint particles M peeled off from the capture member 22) in the exhaust gas Gb are captured between the baffle members 46 due to inertia. Furthermore, by providing the plurality of baffle members 46 radially around the outlet opening 44a of the lower plate 44, the plurality of baffle members 46 can form a stagnation region S for the swirling flow E of the exhaust gas Gb, preventing the captured peeled particles from being re-entrained and preventing the peeled particles from flowing out to the second unit 50.

[0076] According to the gas processing device 101, the baffle member 46 has the dual function of forming a stagnation area S for the exhaust gas Gb and reinforcing the first unit 40, which makes it possible to reduce the number of parts compared to a structure in which each function is realized by a dedicated member.

[0077] According to the gas processing device 101, the swirl diameter r of the swirl flow path 23 of the capture member 22 gradually decreases from the inlet gap of the inlet 23a to the outlet gap of the outlet 23b. This allows the centrifugal force acting on the paint particles M to gradually increase toward the outlet gap. This centrifugal force is used to attach and capture the paint particles M to the flow path wall surface 24 of the capture member 22, thereby improving the capture efficiency of the paint particles M. Furthermore, by selectively capturing coarse particles near the inlet gap of the inlet 23a of the swirl flow path 23 using a relatively weak centrifugal force, it is possible to prevent paint particles M with a wide range of particle diameters from accumulating and clogging near the inlet gap. Meanwhile, near the outlet gap of the outlet 23b of the swirl flow path 23, it is possible to reliably capture fine particles that were not captured upstream using a strong centrifugal force. This prevents high pressure loss due to the accumulation of paint particles M. Furthermore, the reduced pressure loss allows for an increased processing flow rate of the gas Ga.

[0078] Hereinafter, other embodiments related to embodiment 1 will be described with reference to the drawings. In the other embodiments, the same elements as those in embodiment 1 are denoted by the same reference numerals, and the description of the same elements will be omitted.

[0079] (Embodiment 2) 15 and 16, gas processing device 102 of embodiment 2 differs from gas processing device 101 of embodiment 1 in that it does not include air supply duct 10 and transport vehicle 60 and is installed directly on floor surface 7a of baffle chamber 7. Furthermore, in gas processing device 101 of embodiment 1, axis direction C of collection member 22 (see FIG. 4) is disposed vertically so that it is aligned with third direction Z, whereas in gas processing device 102, axis direction C of collection member 22 is disposed horizontally so that it is aligned with first direction X.

[0080] In the gas processing device 102, the collection units 20 of embodiment 1 are stacked in two rows, one above the other, in the third direction Z, and are arranged side by side in two rows in the second direction Y. When the left side of FIG. 16 is the front side of the gas processing device 102, each collection unit 20 can be removed by pulling it out toward the front. In addition, the lower collection unit 20 is positioned to protrude more toward the front than the upper collection unit 20. This makes it easy to remove each collection unit 20.

[0081] The other configurations are the same as those in the first embodiment.

[0082] According to the second embodiment, the gas processing device 102 can be used in a horizontal position. The gas Ga flowing into each collection section 20 from the front side of the gas processing device 102 is processed in two stages using two collection members 22 arranged side by side in the first direction X, and the exhaust gas Gd processed in the recovery section 30 is discharged directly to the baffle chamber 7.

[0083] In addition, the same effects as those of the first embodiment are achieved.

[0084] (Embodiment 3) 17, the gas treatment device 103 of the third embodiment differs from the gas treatment device 102 of the second embodiment in that the collection section 30 is composed of only the second unit 50. That is, in the collection section 30 of the gas treatment device 103, the first unit 40 (see FIG. 16) is omitted.

[0085] The other configurations are the same as those in the second embodiment.

[0086] According to the third embodiment, the structure of the collection section 30 can be simplified.

[0087] In addition, the same effects as those of the second embodiment are achieved.

[0088] The present invention is not limited to the above-described embodiments, and various applications and modifications are possible without departing from the scope of the present invention. For example, the following embodiments can be implemented by applying the above-described embodiments.

[0089] In the above-described embodiment, the gas treatment devices 101, 102, and 103 used in painting equipment for automobile bodies have been illustrated as examples, but these gas treatment devices 101, 102, and 103 can also be applied to painting equipment in fields other than automobiles, as necessary. [Explanation of symbols]

[0090] 22, 22A, 22B, 22C...Collection member, 23...Swirl flow path, 23a...Inlet port, 23b...Outlet port, 24...Flow path wall, 30...Recovery section, 40...First unit, 43...Upper plate section, 43a...Inlet opening, 44...Lower plate section, 44a...Outlet opening, 45...Frame section, 45a...Recovery processing space, 46...Baffle member, 50...Second unit, 54...Filter member, 101, 102, 103...Gas processing device, r...Swirl diameter, A...Radial direction, Ga...Gas, Gb...Exhaust gas, M...Paint particles, Z...Third direction (vertical direction)

Claims

1. A gas treatment device for treating a gas containing paint particles, a collecting member formed in a spiral plate shape, having a swirling flow path extending from an inlet on the outer periphery in the radial direction to an outlet on the center side, and a flow path wall surface that partitions the swirling flow path, and which physically adheres the paint particles to the flow path wall surface to collect them; a collection section that collects the paint particles contained in the exhaust gas that has flowed out from the collection member; A gas treatment device comprising:

2. 2. The gas treatment device according to claim 1, wherein the recovery section comprises: a first unit accommodating a baffle member for forming a stagnation region for the exhaust gas; and a second unit accommodating a filter member for capturing the paint particles that have passed through the baffle member.

3. 3. The gas treatment device according to claim 2, wherein the first unit comprises an upper plate portion having an inlet opening through which the exhaust gas flows while swirling, a lower plate portion having an outlet opening communicating with the second unit, and a frame portion between the upper plate portion and the lower plate portion, wherein the baffle member is interposed in a recovery treatment space of the frame portion, and a plurality of the baffle members are arranged radially around the outlet opening.

4. 4. The gas treatment device according to claim 2, wherein the baffle member also serves as a reinforcing member for reinforcing the first unit.

5. 4. The gas treatment device according to claim 1, wherein the collection member is configured so that a swirl diameter of the swirl flow path gradually decreases from the inlet to the outlet.

6. 6. The gas treatment device according to claim 5, wherein a plurality of the collection members are stacked concentrically in the vertical direction, and the outlet of an upper collection member is configured to communicate with the swirl flow path of a lower collection member.

7. The gas treatment device according to claim 6 , wherein the number of turns of the spiral of the upstream collection member is greater than the number of turns of the spiral of the downstream collection member.

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