Dust collector

Abstract

To provide a compact dust collector which is large in processing air volume, is small in a dead space, and can suppress scattering of fine particles separated from sucked gas.SOLUTION: A dust collector comprises cyclone parts 30, 40, and a fine particle reception part 50. The cyclone parts 30, 40 has cylindrical containers 31, 41 which are so configured as to direct the gas taken in from a duct 10 downwards while revolving the same, and are so arranged as to be adjacent to each other in a horizontal direction. The duct 10 is connected to the containers 31, 41 so that revolution flows in mutually opposite directions are formed in the containers 31, 41 of the cyclone parts 30, 40. The fine particle reception part 50 is arranged below the containers 31, 41, and receives fine particles separated from the gas. A space S, which permits revolution of the gas discharged downward from the containers 31, 41, is formed between the cyclone parts 30, 40 and the fine particle reception part 50.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a dust collecting device for removing fine particles generated by welding. [Background technology]

[0002] Slag and metal particle fine particles (spatter) that are generated and scattered during metal welding adhere to the welded part and the surrounding metal surface, hindering the quality of the weld. For this reason, the generated spatter is removed using a dust collector. A conventional dust collector is equipped with a device (hereinafter also referred to as a cyclone) that separates dust by swirling gas and using the resulting centrifugal force. A cyclone generally has a cylindrical or conical container in which a swirling flow is formed. The container is supplied with gas containing spatter that is sucked in from an inlet at the end of the duct of the dust collector.

[0003] Patent Document 1 describes a dust recovery device equipped with a cyclone. According to this recovery device, mist and dust are sucked into the first screen tank together with the surrounding air from a suction hose, and relatively heavy particles fall due to the swirling air current generated in the first screen tank and the phenomenon of the air flow speed being reduced by the trumpet-shaped member, and then the mist and fine dust remaining in the air are collected in the second screen tank.

[0004] In order to remove large spatters generated during welding, it is necessary to increase the processing air volume of the dust collector and increase the air suction power. However, simply increasing the rotation speed of the dust collector fan to increase the processing air volume increases resistance and makes it impossible to obtain the desired air volume. In order to increase the processing air volume while suppressing resistance, it is preferable to increase the flow passage cross section of the duct and the diameter of the cyclone container. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4112441 Summary of the Invention [Problem to be solved by the invention]

[0006] However, if the diameter of the cyclone container is large, a large installation space is required inside the device, and the dust collector becomes large. In addition, since the housing of the dust collector is often a rectangular parallelepiped, if a large circular container is placed inside the housing, the dead space around the container that does not contribute to dust collection becomes large. In order to reduce the size of the dust collector and the dead space, it is possible to arrange two cyclones with containers that are not too large in diameter side by side. However, it has been found that the fine particles separated from the gas by the cyclone fall from two places, and the area of ​​the part that receives the fallen fine particles (fine particle receiving part) becomes wider according to the diameter of the container, which makes it easier for the spatter separated from the gas to scatter inside the device. If the spatter is scattered and accumulated inside the device, it is difficult to remove the spatter from the device.

[0007] An object of the present invention is to provide a dust collecting device that can treat a large amount of air, is compact, has little dead space, and can suppress the scattering of fine particles separated from the sucked gas. [Means for solving the problem]

[0008] One aspect of the present invention is a dust collection device for removing particulates generated by welding metals. The dust collecting device includes: A duct for sucking in fine particles; a plurality of cyclone units each having a cylindrical container configured to direct the gas containing fine particles taken in from the duct downward while swirling it about an axis extending in a vertical direction, the plurality of cyclone units being arranged adjacent to each other in a horizontal direction, the ducts being connected to the containers of two adjacent cyclone units among the plurality of cyclone units so that swirling flows in mutually opposite directions are formed in the containers of the two cyclone units; A fine particle receiving portion is disposed below the container and receives fine particles separated from the gas, A space is formed between the cyclone section and the fine particle receiving section, which allows the gas discharged downward from the container to swirl.

[0009] The container preferably has a cylindrical side wall open at its lower end.

[0010] The vertical length of the side wall of the container is preferably greater than the diameter of the container.

[0011] Preferably, the space is not partitioned at a horizontal position between the two cyclone sections.

[0012] The cyclone unit further includes a small-diameter cylinder disposed inside the container so as to extend vertically along a center side of the swirling flow, and the gas from which the fine particles have been separated passes through the small-diameter cylinder and is discharged from an upper portion of the container, The dust collecting device includes: a housing having a plurality of walls surrounding the space together with the cyclone section; an air filter having a filtering surface extending in a direction parallel to the direction in which the two cyclone sections are arranged and the vertical direction, through which the air discharged from the small diameter cylinder passes; It is preferable that one of the walls is arranged to separate the filtering surface of the air filter from the space.

[0013] The diameter of the container is preferably 200 mm or more.

[0014] It is preferable that the wind speed at which the duct sucks in the fine particles is 10 m / sec or more.

[0015] The plurality of cyclone sections include at least one third cyclone section in addition to the two cyclone sections, and the third cyclone section has a cylindrical container configured to direct the gas containing fine particles taken in from the duct downward while rotating it about an axis extending in a vertical direction, It is preferable that the container of the third cyclone section is connected to a branching portion of the duct branching off from a portion of the duct connected to the containers of the two cyclone sections so that a swirling flow in a direction opposite to that of the other cyclone sections adjacent to the third cyclone section among the plurality of cyclone sections is formed. Effect of the Invention

[0016] According to the above aspect, the processing volume of air is large, the size is reduced, the dead space is small, and scattering of fine particles separated from the sucked gas can be suppressed. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is an external perspective view showing a main body of the dust collecting device according to the embodiment. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. 13 is a diagram illustrating a dead space around a cyclone portion. [Figure 6] FIG. 4 is a diagram illustrating the flow of gas discharged from a cyclone portion. [Figure 7] FIG. 11 is a top view showing a schematic view of a part of the device body according to a modified example. [Figure 8] 13(a) and 13(b) are diagrams showing the scattering state of fine particles accumulated in a fine particle receiving portion in an example and a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The dust collecting device of this embodiment will be described below.

[0019] Fig. 1 is an external perspective view showing the main body of a dust collecting device. Fig. 2 is a side view showing the main body. Fig. 3 is a top view showing the main body. Fig. 4 is a front view showing the main body. Figs. 1 to 4 also show a part of the internal structure of the main body.

[0020] The dust collector 1 is a device for removing fine particles (hereinafter simply referred to as fine particles) that are generated and scattered by metal welding. Such fine particles are called spatter and include slag and metal particles. Spatter is mainly generated by fusion joining such as arc welding and gas welding, brazing and soldering (brazing) in which wax or solder is used for joining.

[0021] The dust collecting device 1 includes a duct 10 and a device main body 20 .

[0022] The duct 10 is a member for sucking in fine particles, and is a hollow, elongated member. One end (tip) in the longitudinal direction of the duct 10 has an inlet (not shown) for sucking in air containing fine particles. The other end in the longitudinal direction of the duct 10 is connected to a connection part 21 of the device main body 20. The duct 10 is configured so that the position and direction of the inlet can be adjusted, and the inlet can be brought close to spatters that are generated and scattered during welding. The duct 10 is configured so that at least a part of the longitudinal direction of the duct 10 is expandable and contractable, and is, for example, a hose that can expand and contract, such as a bellows hose. The material of the bellows hose is, for example, aluminum or an aluminum alloy.

[0023] The device body 20 is the main body of the dust collecting device 1 to which the duct 10 is connected. The device body 20 includes a plurality of cyclone units 30, 40 and a fine particle receiving unit 50.

[0024] The cyclone units 30 and 40 are arranged so as to be adjacent to each other in the horizontal direction. This allows the dead space in the dust collector 1 to be reduced, as shown in FIG. 5(a). FIG. 5(a) is a top view illustrating the dead space around the cyclone units 30 and 40, and FIG. 5(b) is a top view illustrating the dead space around the cyclone unit of the reference example. The dust collector of the reference example has a large diameter of the container so that a single cyclone unit can process a large amount of air. Comparing FIG. 5(a) and FIG. 5(b), it can be seen that the area of ​​the dead space marked with diagonal lines can be reduced by arranging multiple cyclone units 30 and 40 so as to be adjacent to each other in the horizontal direction.

[0025] Furthermore, since the dust collector 1 is provided with a plurality of cyclone sections 30, 40, the processing air volume can be increased. In the example shown in Figs. 1 to 4, the processing air volume is doubled compared to a dust collector provided with only one cyclone section of the same size as the cyclone sections 30, 40. In the dust collector 1, the cyclone sections 30, 40 are smaller than the cyclone section of the reference example in Fig. 5(b), so the processing air volume per cyclone section is smaller. However, the air in the duct 10 is divided into two and taken into the cyclone sections 30, 40, and the air volume is halved in each of the cyclone sections 30, 40, so that an increase in resistance due to a smaller diameter of the container than the cyclone section of the reference example is suppressed, and a decrease in the air volume is suppressed. Furthermore, in dust collecting device 1, cyclone units 30 and 40 are smaller than the cyclone unit of the reference example, so that as shown in Fig. 5(a), the device can be made smaller in the depth direction (Y direction), thereby making it possible to miniaturize dust collecting device 1. Therefore, according to dust collecting device 1, the dead space is smaller, the device can be made smaller, and the processing air volume can be secured, compared to a dust collecting device equipped with only one cyclone unit having a large-diameter container to increase the processing air volume.

[0026] The cyclone units 30, 40 have containers 31, 41. The containers 31, 41 are cylindrical members configured to direct the air containing fine particles taken in from the duct 10 downward while swirling it around an axis 1 (see FIG. 2) extending in the vertical direction (Z direction). Such a swirling flow is formed in the containers 31, 41 by operation of a blower 100 of the dust collecting device 1, which will be described later. By generating such a swirling flow in the containers 31, 41, centrifugal force is applied to the fine particles in the air taken in from the duct 10, causing them to separate and fall by gravity.

[0027] The duct 10 is connected to the containers 31 and 41 so that swirling flows are formed in opposite directions. The connection part 21 of the device body 20 to which the duct 10 is connected is a tubular part that communicates the containers 31 and 41 with the duct 10, and is airtightly joined to the inlets 31a and 41a formed by cutting out a part of the cylindrical side wall of the containers 31 and 41. By connecting the duct 10 to the containers 31 and 41 in this manner, the gas discharged from each of the containers 31 and 41 is likely to maintain a downward swirling gas flow even when the gases are joined below the containers 31 and 41. If the swirling flows formed in the containers 31 and 41 are in the same direction, the high-speed air flows discharged from the containers 31 and 41 will collide with each other and become turbulent, and fine particles separated from the gas will be scattered over a wide area. As shown in Figs. 3 and 4, the connection part 21 of the device main body 20 is connected to the containers 31 and 41 so that the center of the flow path of the connection part 21 passes between the containers 31 and 41 (the position where the side walls of the containers 31 and 41 contact each other in the illustrated example). This makes the amount of gas entering the containers 31 and 41 from the duct 10 equal, and creates a swirling flow with an equal air volume. The inlets 31a and 41a are preferably provided at the upper ends of the containers 31 and 41 as shown in Figs. 2 and 4. This makes it easy to create a swirling flow that stably flows downward in the containers 31 and 41. The connection part 21 preferably has a circular cross section and a diameter that is approximately equal to the diameter of the duct 10.

[0028] In order to make the magnitudes of the swirling flows in the opposite directions equal to each other, the vessels 31 and 41 are preferably of the same size and are preferably symmetrical (mirror-image) with respect to a plane passing between the cyclone sections 30 and 40. In addition, in order to make it easier for the swirling flows in the opposite directions to join below the vessels 31 and 41, it is preferable that the side walls of the vessels 31 and 41 are in contact with each other.

[0029] The particulate receiving section 50 is disposed below the containers 31, 41, and is a part of the dust collecting device 1 that receives particulates separated from the gas. The particulate receiving section 50 in the illustrated example is made up of a bottom plate 66 of a housing 60, which will be described later. The wall section (bottom plate) 66 forms part of the casing of a front section 20A, which will be described later, of the dust collecting device 1. Particulates may collide with the particulate receiving section 50 and be separated from the gas.

[0030] Between the cyclone section 30, 40 and the fine particle receiving section 50, a space S is formed that allows the gas discharged downward from the container 31, 41 to swirl. According to the study by the present inventor, it has been found that the formation of the space S can suppress the scattering of fine particles separated from the gas. The gas discharged from the container 31, 41 gradually decreases in speed while swirling within the space S, so that the falling fine particles tend to gather locally on the fine particle receiving section 50. Specifically, such space S has a wide area that encompasses the opening areas of the lower ends of cyclone sections 30, 40 (the lower ends of containers 31, 41 in the illustrated example) in a cross section perpendicular to the vertical direction, and preferably has a length that is 2.45 to 2.6 times the diameter of containers 31, 41 in the direction in which cyclone sections 30, 40 are lined up (X direction), a length that is 1.05 to 1.25 times the diameter of containers 31, 41 in the depth direction of apparatus body 20 (Y direction), and a length that is 0.8 to 1.2 times the diameter of containers 31, 41 in the vertical direction (Z direction).

[0031] Preferable dimensions of the space S include the following dimensions: · X-direction length of space S: 400~600mm -Y direction length of space S: 200~280mm ·Z-direction length of space S: 150~250mm

[0032] According to the dust collecting device 1 described above, the processing volume of air is large, it can be made compact, the dead space is small, and scattering of fine particles separated from the sucked gas can be suppressed.

[0033] As shown in the example, the containers 31 and 41 preferably have a cylindrical side wall with an open lower end. This makes it easier for the size (diameter) of the swirling flow formed in the containers 31 and 41 to be maintained in the space S even after the swirling flow is discharged from the containers 31 and 41, and makes it easier to locally collect the falling fine particles on the fine particle receiving section 50. If the lower end of a container with a large diameter is open, there is a concern that the fine particles will fall over a wide area, but by maintaining the swirling flow in the space S, the fine particles are unexpectedly more likely to be collected. If the lower end of the containers 31 and 41 is not open and is connected to another container, for example, a truncated cone-shaped container tapered downward, the size (diameter) of the swirling flow discharged to the space S will be small or will not swirl depending on the diameter of the lower end of the container, making it difficult to locally collect the falling fine particles on the fine particle receiving section 50.

[0034] The vertical length L (FIGS. 2 and 4) of the side wall of the container 31, 41 is preferably longer than the diameter of the container 31, 41. If the length L is shorter than the diameter of the container 31, 41, it is considered that the speed of the gas discharged from the container 31, 41 is too fast, adversely affecting the effect of the falling fine particles locally gathering on the fine particle receiver 50. The ratio of the length L to the diameter of the container 31, 41 is preferably 1.1 to 1.7, and more preferably 1.2 to 1.5.

[0035] The diameter of the containers 31, 41 is preferably 200 mm or more. When the processing air volume of the dust collector 1 is increased, the flow path cross-sectional area of ​​the duct 10 and the diameters of the containers 31, 41 must be increased accordingly, otherwise resistance will increase. Even if the flow path cross-sectional area of ​​the duct 10 is increased, if the diameters of the containers 31, 41 are small, resistance will increase and the air volume will decrease. Therefore, the diameter of the containers 31, 41 is preferably 200 mm or more, and more preferably 210 mm or more. From the viewpoint of miniaturization of the dust collector 1, the upper limit of the diameter of the containers 31, 41 is, for example, 300 mm.

[0036] It is preferable that the space S is not divided at the horizontal position between the cyclone sections 30 and 40. This makes it easier for the gases discharged from the containers 31 and 41 to join together in the portion between the cyclone sections 30 and 40 in the space S, which increases the effect of maintaining the downward swirling gas flow.

[0037] It is preferable that the cyclone section 30, 40 further has a small diameter cylinder 32, 42 inside the container 31, 41. The small diameter cylinder 32, 42 is a cylinder provided so as to extend vertically on the center side of the swirling flow. The inventor modeled the dust collector 1 and the air volume and fine particles of the gas taken into the dust collector 1, and performed a computer simulation of the gas flow during dust collection. It was confirmed that when the small diameter cylinder 32, 42 is present in the cyclone section 30, 40, the gas discharged into the space S while separating fine particles collides with the fine particle receiving section 50 while swirling, as shown in FIG. 6, flows toward the center side of the swirling flow, then rises, and is discharged through the small diameter cylinder 32, 42. FIG. 6 is a diagram explaining the flow of gas discharged from the cyclone section. Such a gas flow contributes to maintaining the gas flow swirling downward in the space S.

[0038] In the illustrated example, the containers 31, 41 and the small diameter cylinders 32, 42 are connected by the upper plate 61 of the housing 60 described later. In this way, the gap between the containers 31, 41 and the small diameter cylinders 32, 42 is blocked, so that a stable downward swirling flow is easily formed in the containers 31, 41. In the illustrated example, the upper plate 61 of the housing 60 connects the upper ends of the containers 31, 41 and the upper ends of the small diameter cylinders 32, 42, which are arranged at the same height. The thinner the small diameter cylinders 32, 42 are, the easier it is to form an air flow that rises on the center side of the swirling flow. However, if the small diameter cylinders 32, 42 are too thin, the amount of gas that rises is reduced, and it may be difficult to generate a swirling gas flow in the space S. The diameter of the small diameter cylinders 32, 42 is preferably 1 / 4 to 1 / 2 of the diameter of the containers 31, 41, and more preferably 1 / 3.5 to 1 / 2.5.

[0039] The dust collecting device 1 preferably further includes a housing 60 and an air filter 70 .

[0040] The housing 60 has a plurality of walls 61-66 that surround the space S together with the cyclone units 30, 40. The housing 60 in the illustrated example has a wall (upper plate) 61, a wall (front plate) 62, a wall (rear plate) 63, walls (side plates) 64, 65, and a wall (bottom plate) 66 that extend along each of the six faces of the rectangular parallelepiped. Therefore, the space S in the illustrated example is surrounded by the five walls 62-66 below the cyclone units 30, 40.

[0041] The air filter 70 purifies the gas discharged from the small diameter cylinders 32 and 42 by passing through it. The air filter 70 includes a filter medium made of a nonwoven fabric of glass fiber or organic fiber, and a frame surrounding the filter medium. The filtering performance of the filter medium is not particularly limited, but a filter medium having a filtering performance of 20 to 99% by a counting method can be used as a medium performance filter. The filter medium is, for example, pleated and held inside the frame together with a member for maintaining the pleat interval. The air filter 70 has a filtering surface 70a formed by the filter medium extending inside the frame. The filtering surface 70a extends in a plane direction parallel to the direction in which the cyclone units 30 and 40 are arranged (X direction) and the vertical direction (Z direction).

[0042] The wall (back plate) 63, which is one of the walls 61 to 66 of the housing 60, is preferably disposed so as to separate the filtering surface 70a of the air filter 70 from the space S. This makes it possible to prevent the gas discharged downward from the containers 31 and 41 and containing fine particles from flowing toward the air filter 70. The upper end of the wall (back plate) 63 is connected to the wall (upper plate) 61, and the upper part of the wall (back plate) 63 is open so as to communicate the space inside the small diameter cylinders 32 and 42 with the space on the air filter 70 side. The wall (front plate) 62, the wall (side plates) 64 and 65, and the wall (bottom plate) 66 form a part of the outer housing of the device main body 20 (the front stage 20A described later). The wall (bottom plate) 66 forms the fine particle receiving section 50.

[0043] The dust collecting device 1 preferably further includes at least one prefilter 80, 90 arranged upstream of the air flow path in the device body 20 with respect to the air filter 70. The prefilters 80, 90 have a mat-like or felt-like filter material made of, for example, glass fiber (wet nonwoven fabric, long fiber, short fiber) or organic fiber. The filtering performance of the filter material of the prefilters 80, 90 is, for example, 30 to 99% by mass method. The filtering performance of the filter material of the prefilters 80, 90 is preferably different from each other, but may be the same.

[0044] As shown in the example, the dust collector 1 preferably has a front stage 20A and a rear stage 20B, which are formed by dividing the dust collector 1 into two. The front stage 20A has the above-mentioned cyclone sections 30 and 40, the fine particle receiving section 50, and the housing 60. The front stage 20A is a section for mainly separating relatively large fine particles having heat from the gas taken in from the duct 10. The size of the fine particles separated in the front stage 20A is, for example, 0.1 to 5 μm. The rear stage 20B has the above-mentioned air filter 70 and pre-filters 80 and 90. The rear stage 20B is a section for mainly separating and purifying relatively small fine particles from the gas from which the relatively large fine particles have been separated in the front stage 20A.

[0045] As shown in the figure, the front stage 20A and the rear stage 20B are connected to each other at one side of the housing by a hinge 20c (only shown in FIG. 1), and the dust collector 1 can be opened and closed between the front stage 20A and the rear stage 20B. This makes it possible to open the front stage 20A and the rear stage 20B periodically or irregularly to remove fine particles accumulated in the fine particle receiving section 50 of the front stage 20A and replace the filters 70 to 90 of the rear stage 20B. When removing fine particles from the front stage 20A, the wall section (rear plate) 63 of the housing 60 forming the rear surface of the front stage 20A is removed to open the fine particle receiving section 50 and perform the work.

[0046] The dust collector 1 further includes a blower 100 and an exhaust port (not shown) in the rear stage 20B. The blower 100 includes a fan and a motor (not shown), and the motor and the fan are driven to rotate by an external power source to suck in gas containing fine particles from the inlet of the duct 10 and exhaust it from the exhaust port. The suction wind speed at the inlet is preferably 10 m / s or more, more preferably 12 m / s or more. By sucking in air at such a wind speed and increasing the processing air volume, large fine particles can be sucked in. In addition, when the wind speed is high, a fast swirling flow is easily formed, and more fine particles can be separated and the collection rate can be increased. In order to increase the processing air volume in this way, it is preferable that the flow path cross-sectional area of ​​the duct 10 is large, and for example, the diameter of the duct 10 is 100 mm or more, preferably 120 mm or more, for example, 200 mm or less. The processing air volume is adjusted by adjusting the rotation speed of the fan. When the processing air volume is increased, negative pressure is created inside the dust collector 1. The pressure inside the dust collector 1 during dust collection is preferably −400 to −600 Pa relative to atmospheric pressure.

[0047] The exhaust port is, for example, a plurality of holes (not shown) provided in a portion of the housing forming the side surface opposite to the side surface on which the hinge 20c is provided, among both side surfaces of the rear section 20B.

[0048] (Modification) FIG. 7 is a top view that diagrammatically shows a part of the device body 20 of a modified example. As in the modified example, the dust collecting device 1 may include at least one third cyclone section 110 as the multiple cyclone sections in addition to the two cyclone sections 30, 40. The third cyclone section 110 is preferably connected to a branch section 11 of the duct 10 branched from a portion of the duct 10 connected to the containers 31, 41 of the cyclone sections 30, 40 so that swirling flows in the opposite directions to the third cyclone section 110 and the cyclone section 40 adjacent to it are formed. For this reason, it is preferable that the branch section 11 of the duct 10 is connected to a portion of the container of the third cyclone section 110 that is farthest from the cyclone section 40 adjacent to the third cyclone section 110. The swirling flow discharged from the third cyclone section 110 in the above-mentioned direction becomes the same as the direction of the gas discharged from the cyclone section 40 between the third cyclone section 110 and the cyclone section 40, so that even if the gases join below the container, the gases contribute to maintaining the downward swirling flow. According to the modified example, the gas flowing through the duct 10 can be divided into larger portions and supplied to each cyclone section, and the amount of air supplied to each cyclone section can be reduced, so that resistance can be suppressed even if each cyclone section is small. Therefore, the cyclone section can be made even smaller, the dust collector 1 can be made more compact, the dead space can be reduced, and the amount of air to be treated can be ensured.

[0049] The multiple cyclone sections 30, 40, 110 are preferably arranged in a horizontal line. The cyclone section 110 is preferably the same size as the cyclone sections 30, 40, and is preferably symmetrical (mirror-image) with respect to a plane passing between the cyclone sections 110, 40. In addition, the side walls of the containers of the cyclone sections 110, 40 are preferably in contact with each other so that the swirling flows in opposite directions can easily join together below the container.

[0050] (Examples and Comparative Examples) In order to examine the effect of the present invention, various dust collecting devices with different specifications were fabricated as described below, and the degree of dispersion of fine particles was confirmed. Example 1 Based on the dust collector configuration shown in Figure 1, the following dimensions were adopted. Diameter of containers 31, 41: 220mm Height of containers 31 and 41 (length in Z direction): 260 mm Diameter of small cylinders 32 and 42: 80mm Height of small diameter cylinders 32 and 42: 185mm · X-direction length of space S: 550mm ·Z-direction length of space S: 200mm -Y direction length of space S: 250mm Duct diameter: 133mm An aluminum bellows hose was used for the duct.

[0051] The SUS structural materials were joined together by arc welding, and during this process, the suction port of the prototype dust collector duct was brought close to the welded area and a fan was operated to suck in the fine particles that were generated and scattered by the welding. The fan speed was adjusted so that the wind speed (suction speed) of the gas sucked in from the suction port was 12 m / s, as measured by an anemometer. The pressure inside the front section 20A relative to atmospheric pressure, measured by a negative pressure gauge, was -400 to -600 Pa.

[0052] After five 30-minute welding operations, the dust collector was opened, the rear plate of the housing was removed from the front section, and the scattering of the fine particles accumulated on the surface of the fine particle receiving section was observed. Fig. 8(a) shows the observation results of Example 1. Fig. 8 divides the surface of the fine particle receiving section 50 into a grid pattern, and the amount of fine particles in each section is shown in four levels: black (very much, accumulated), dark gray (a lot), light gray (a little), and white (almost none or none). The dashed circle in Fig. 8 represents the outline of the container projected in the Z direction onto the surface of the fine particle receiving section.

[0053] Comparative Example 1 The same procedure as in Example 1 was used, except that a truncated cone-shaped container tapered downward was used instead of the cylindrical container, the diameter of the opening at the bottom end of the container was made smaller than the diameter of the small-diameter cylinder, and the height of the small-diameter cylinder was shortened so as not to come into contact with the wall of the container. The observation results are shown in Figure 8(b).

[0054] Comparing Figure 8(a) and Figure 8(b) shows that when the cyclone section is equipped with a cylindrical container, the scattering of fine particles accumulated in the fine particle receiving section is suppressed.

[0055] Comparative Example 2 Except for the fact that the side wall of the container was lengthened so that the bottom end of the container reached the particulate receiving part, the same procedure was followed as in Example 1. When the particulate receiving part was gently removed from the housing and the degree of scattering of the particulates was observed, the particulates were found to have been scattered over almost the entire area of ​​the two circular regions.

[0056] Comparative Example 3 The procedure was the same as in Example 1, except that the particle receiver was brought closer to (raised higher than) the container so that the distance from the bottom end of the container (the length of the space S in the Z direction) was 30 mm.

[0057] Comparing the observation results of Comparative Examples 1 to 3, the order of greatest degree of dispersion of fine particles was Comparative Example 3, Comparative Example 2, and Comparative Example 1.

[0058] Example 2 The same as in Example 1 was performed, except that a partition plate was provided at a horizontal position between the cyclone sections 30 and 40 so as to divide the space S in two in the X direction.

[0059] Example 3 The embodiment was the same as Example 1, except that the length of the containers 31 and 41 in the vertical direction (Z direction) was set to 180 mm, which is shorter than the diameter of the containers 31 and 41.

[0060] Example 4 The same as in Example 1, except that the lower ends of the cylindrical containers 31 and 41 were connected to a truncated cone-shaped container. The diameter of the upper end of the truncated cone-shaped container was equal to the diameter of the containers 31 and 41, the diameter of the opening at the lower end was 140 mm, which was larger than the diameter of the small diameter cylinders 32 and 42, and the length in the vertical direction (Z direction) was half the height of the cylindrical containers 31 and 41. Although the fine particles were slightly scattered more than in Example 1, the scattering of the fine particles was smaller than in the comparative example, and they were gathered in the center of the lower part of the containers 31 and 41. Since the diameter of the opening at the lower end of the truncated cone-shaped container was large and the tapering was gradual, it is considered that a swirling flow downward in the space was maintained to some extent.

[0061] Comparing the observation results of Examples 1 to 4, the order of greatest effect in suppressing scattering of fine particles was Example 1, Example 4, Example 2, and Example 3. All of Examples 1 to 4 suppressed scattering of fine particles more than Comparative Example 1, which had the smallest degree of scattering of fine particles among Comparative Examples 1 to 3.

[0062] The dust collecting device of the present invention has been described in detail above, but the dust collecting device of the present invention is not limited to the above embodiment, and various improvements and modifications may be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0063] 1 Dust collector 10 Duct 11 Branch 20. Device body 20A front section 20B Rear section 20c hinge 21 Connection 30, 40, 110 Cyclone section 31, 41 container 31a, 41a intake 32, 42 Small diameter cylinder 50 Particulate receiver 60 Housing 61, 62, 63, 64, 65, 66 Wall section 70 Air Filter 70a filtration surface 80, 90 Prefilter 100 Blower

Claims

1. A dust collecting device for removing fine particles generated by metal welding, comprising: A duct for sucking in fine particles; a plurality of cyclone units each having a cylindrical container configured to direct the gas containing fine particles taken in from the duct downward while swirling it about an axis extending in a vertical direction, the plurality of cyclone units being arranged adjacent to each other in a horizontal direction, the duct being connected to the containers of two adjacent cyclone units among the plurality of cyclone units so that swirling flows in mutually opposite directions are formed in the containers of the two cyclone units; A fine particle receiving portion is disposed below the container and receives fine particles separated from the gas, A dust collecting device, characterized in that a space is formed between the cyclone section and the fine particle receiving section, the space allowing swirling of gas discharged downward from the container.

2. The dust collecting apparatus of claim 1 , wherein the container has a cylindrical side wall that is open at a lower end.

3. The dust collecting apparatus according to claim 2 , wherein a vertical length of the side wall of the container is longer than a diameter of the container.

4. 3. The dust collecting apparatus according to claim 1, wherein the space is not partitioned at a horizontal position between the two cyclone sections.

5. the cyclone section further includes a small-diameter cylinder disposed inside the container so as to extend vertically along a center side of the swirling flow, and the gas from which the fine particles have been separated passes through the small-diameter cylinder and is discharged from an upper portion of the container; The dust collecting device includes: a housing having a plurality of walls surrounding the space together with the cyclone section; an air filter having a filtering surface extending in a direction parallel to the direction in which the two cyclone sections are arranged and the vertical direction, through which the air discharged from the small diameter cylinder passes; The dust collecting device according to claim 1 or 2, wherein one of the walls is disposed so as to separate the filtering surface of the air filter from the space.

6. 3. The dust collecting device according to claim 1 or 2, wherein the diameter of the container is 200 mm or more.

7. 3. The dust collecting device according to claim 1, wherein the wind speed at which the duct sucks in the fine particles is 10 m / sec or more.

8. The plurality of cyclone sections include at least one third cyclone section in addition to the two cyclone sections, and the third cyclone section has a cylindrical container configured to direct the gas containing fine particles taken in from the duct downward while rotating it about an axis extending in a vertical direction, 3. The dust collecting device according to claim 1, wherein the container of the third cyclone unit is connected to a branching portion of the duct branching off from a portion of the duct connected to the containers of the two cyclone units so that a swirling flow in a direction opposite to that of another cyclone unit adjacent to the third cyclone unit among the plurality of cyclone units is formed.

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