JP7653330B2 - Exhaust device and exhaust method - Google Patents

Description

This disclosure relates to an exhaust device and exhaust method that collects and exhausts minute particles such as fumes and dust generated during welding, melting, cutting, and other operations.

In general, in processes such as welding and melting, cutting, and spraying disinfectants for sterilization, fumes, dust, and tiny droplets are generated by the heating and sublimation of materials. These fumes, dust, and tiny droplets (hereafter simply referred to as fumes) are tiny particles that are scattered and dispersed by air currents generated in each process, air currents from indoor air conditioning or ventilation equipment, and convection currents caused by temperature differences. For example, in thermal processing processes using lasers or gases, fumes tend to diffuse and remain upwards, while in mechanical processing processes, dust tends to remain relatively downwards.

Known technologies for preventing this type of fume from scattering or diffusing include the installation of a shielding device that physically encloses processing equipment such as welding machines from the outside, and the installation of a device that sucks in the fumes using a large local exhaust system (see, for example, Patent Document 1). Also proposed is an exhaust system that uses an air curtain of air jets to shield the area around the fumes and suck in the fumes (see, for example, Patent Document 2).

JP 2000-146247 A JP 2019-132487 A

However, if the processing equipment is enclosed by a shielding device, it becomes difficult to load and unload workpieces into and out of the processing equipment, and the size of the workpieces that can be processed is limited. Furthermore, when a large local exhaust device is installed, the suction port must be located close to the processing position, but if it is located too close, it will interfere with the processing work. However, if the suction port is moved away from the processing position, the suction force must be increased accordingly, which will lead to an even larger exhaust device. In response to this, a method using an air curtain with an air jet stream can improve workability, but there is still room for improvement in terms of efficiently collecting the fumes that are generated.

The present disclosure aims to solve the above-mentioned problems and provide an exhaust device and exhaust method that can efficiently collect fumes and other substances generated without interfering with processing operations.

The exhaust device of the present disclosure for achieving the above object includes a housing having a first opening, a partition member having a second opening provided in the housing with a first gap inside the first opening, a suction hood having a third opening provided in the partition member with a second gap inside the second opening, a shielding member provided in the suction hood with a third gap inside the third opening, a fluid supply device that supplies fluid into the housing and the partition member, and a suction device that draws into the suction hood.

The exhaust method disclosed herein is an exhaust method using an exhaust device including a housing having a first opening, a partition member having a second opening provided in the housing with a first gap inside the first opening, a suction hood having a third opening provided in the partition member with a second gap inside the second opening, and a shielding member provided in the suction hood with a third gap inside the third opening, and includes the steps of ejecting a first jet from the first gap, ejecting a second jet from the second gap along the first jet, and sucking in a fluid from the third gap.

According to this disclosure, fumes and other substances that are generated can be efficiently collected without interfering with processing operations.

FIG. 1 is a schematic side view showing an exhaust device according to a first embodiment. FIG. 2 is a schematic front view showing the exhaust device. FIG. 3 is a schematic front view showing a modified example of the exhaust device of the first embodiment. FIG. 4 is a schematic diagram illustrating the flow of air in the exhaust system of the first embodiment. FIG. 5 is a schematic side view showing the exhaust device of the second embodiment. FIG. 6 is a schematic view showing a main part of an exhaust device according to the third embodiment.

Below, a preferred embodiment of the exhaust system according to the present disclosure will be described in detail with reference to the attached drawings. Note that the present disclosure is not limited to this embodiment, and when there are multiple embodiments, the present disclosure also includes a configuration in which each embodiment is combined.

[First embodiment]
FIG. 1 is a schematic side view showing an exhaust device according to a first embodiment, and FIG. 2 is a schematic front view showing the exhaust device.

In the first embodiment, as shown in Figs. 1 and 2, the exhaust device 1 collects and exhausts fumes generated by, for example, cutting work inside a building. In the example of Fig. 1, the exhaust device 1 is placed on the opposite side of the work object (e.g., a metal plate) 100 from the work side, and sucks in and collects fumes H generated by cutting work on the work object 100. In this case, oxygen gas (assist gas) used for cutting, for example, flows into the exhaust device 1 side through the cutting section 100A together with the fumes H. However, the exhaust device 1 is not limited to this, and may collect and exhaust dust and fumes generated by cutting work or welding work inside a building, and microdroplets generated by spraying disinfectant.

The exhaust device 1 includes a housing 10, a partition member 11, a suction hood 12, a shielding member 13, a first blower fan (fluid supply device) 14A, a second blower fan (fluid supply device) 14B, and a suction fan (suction device) 15.

The housing 10 has a hollow cylindrical shape and is provided with a first opening 21 on one side in the axial direction. The housing 10 has a closure portion 23 fixed integrally to one side in the axial direction of a cylindrical portion 22, and the first opening 21 is formed on the other side in the axial direction. The housing 10 has a support portion 24 fixed to the lower outer periphery, and a plurality of casters (wheels) 25 attached to the lower portion of the support portion 24.

The partition member 11 is disposed inside the housing 10 and has a second opening 32 provided inside the first opening 21 of the housing 10 with a first gap 31 therebetween. The partition member 11 has a conical portion 33 having a cylindrical shape resembling a truncated cone, with one axial end of the conical portion 33 fixed to the closing portion 23 of the housing 10 and the other axial end expanding in diameter to provide the second opening 32.

The suction hood 12 is disposed inside the partition member 11, and a third opening 42 is provided inside the second opening 32 of the partition member 11 with a second gap 41 therebetween. The suction hood 12 is composed of a cylindrical portion 43 and a truncated cone-shaped conical portion 44, and one axial end of the cylindrical portion 43 is fixed by penetrating the closing portion 23 of the housing 10, and the other axial end is connected to the conical portion 44. One axial end of the conical portion 44 is connected to the cylindrical portion 43, and the other axial end is expanded to provide the third opening 42.

The shielding member 13 is disposed inside the suction hood 12, and is provided with a third gap 45 inside the third opening 42 of the suction hood 12. The shielding member 13 has a disk shape, and its outer periphery is connected to the tip of the cone portion 44 of the suction hood 12 via multiple connecting members 46 (four in this embodiment).

The first gap 31 formed by the housing 10 and the partition member 11 is provided along the circumferential direction of the first opening 21 and functions as an outlet (hereinafter referred to as the first outlet 31) for ejecting air (fluid). The second gap 41 formed by the partition member 11 and the suction hood 12 is provided along the circumferential direction of the second opening 32 and functions as an outlet (hereinafter referred to as the second outlet 41) for ejecting air (fluid). The third gap 45 formed by the suction hood 12 and the shielding member 13 is provided along the circumferential direction of the third opening 42 and functions as an inlet (hereinafter referred to as the inlet 45) for sucking outside air into the suction hood 12. The first outlet 31, the second outlet 41, and the inlet 45 each have a throttle shape.

The first blower fans 14A supply air (fluid) into the housing 10, and are attached to the closing portion 23 of the housing 10 at equal intervals in the circumferential direction, with the first ducts 51A fixed thereto, protruding outward. Therefore, when each first blower fan 14A is driven, outside air is supplied from each first duct 51A to the first space 52A between the housing 10 and the partition member 11, and this air is ejected as an air curtain (first jet) from the first jet 31. The air curtain is a gas jet for separating the suction side space (inner space) from the surrounding space without providing a physical partition such as a wall or membrane, and surrounds the fumes H generated in the suction side space to prevent the fumes H from scattering and diffusing into the surrounding space.

The suction hood 12 has one end of a connecting duct 61 connected to a position facing the third opening outside the housing 10, i.e., to the cylindrical portion 43. The connecting duct 61 is bellows-shaped, making it expandable and foldable. The other end of the connecting duct 61 is connected to the suction fan 15, which is connected to an exhaust duct 62. A filter 63 is detachably attached to the outlet of the exhaust duct 62. A number of casters (wheels) 64, 65 are attached to the bottom of the suction fan 15 and the exhaust duct 62.

Therefore, when the suction fan 15 is driven, a suction force acts on the inside of the suction hood 12 via the connecting duct 61, and air containing fumes H generated in the suction side space separated by the air curtain described above can be sucked in from the suction port 45. The air sucked in from this suction port 45 flows through the connecting duct 61 and the suction fan 15 to the exhaust duct 62, where foreign matter (tiny particles) are removed by the filter 63 before being discharged to the outside.

Here, the housing 10, the suction hood 12, the shielding member 13, the first blower fan 14A, and the second blower fan 14B can be moved on the floor surface G by the casters 25. Also, the suction fan 15 and the exhaust duct 62 can be moved on the floor surface G by the casters 64, 65. In this case, since each caster 25, 64, 65 is provided with a stopper (not shown), when the exhaust device 1 is used, the stopper makes each caster 25, 64, 65 unable to rotate, and the housing 10, the partition member 11, the suction hood 12, the shielding member 13, the first blower fan 14A, the second blower fan 14B, the suction fan 15, and the exhaust duct 62 unable to move. On the other hand, when the exhaust device 1 is used in another location, the stoppers allow the casters 25, 64, and 65 to rotate, and the housing 10, partition member 11, suction hood 12, shielding member 13, first blower fan 14A, and second blower fan 14B, or in addition, the suction fan 15 and exhaust duct 62, to be movable.

As described above, when the first blower fan 14A is driven, air is ejected from the first outlet 31 as an air curtain, which can prevent the fumes H generated in the suction side space from scattering and diffusing into the surrounding space. On the other hand, when the air curtain is ejected, the jet of the air curtain generates an entrained flow in both the suction side space (inner space) and the surrounding space (outer space). This entrained flow is a flow of air (fluid) that is generated as if it is drawn into the jet of the air curtain. In addition, when the air curtain is ejected, the suction side space of the air curtain is almost closed. Therefore, when an entrained flow occurs in the suction side space, air of a flow rate equivalent to this entrained flow is not supplied from the outside to the suction side space, and the entrained flow becomes a circulating vortex if it is left as it is. Since the size and strength of this type of circulating vortex fluctuates over time or space, it is assumed that when a circulating vortex occurs, the flow of the air curtain becomes unstable, and the air curtain breaks locally, causing the fumes H in the suction side space to leak into the surrounding space.

For this reason, in this embodiment, the exhaust device 1 is configured to eject an air flow (entrainment flow suppression air flow; second jet flow) from the second jet port 41 formed by the partition member 11 and the suction hood 12. Specifically, the exhaust device 1 is equipped with a second blower fan 14B that supplies air (fluid) into the partition member 11. A plurality of second blower fans 14B are attached to the blocking portion 23 of the housing 10 at equal intervals in the circumferential direction, inside the first blower fan 14A, and a second duct 51B protruding outward is fixed to the second blower fan 14B. For this reason, when each second blower fan 14B is driven, outside air is supplied from each second duct 51B to the second space portion 52B between the partition member 11 and the suction hood 12, and this air is ejected from the second jet port 41 into the suction side space (inner space) along the jet flow of the air curtain.

Here, the flow velocity (also called speed) of the air (fluid) ejected from the second nozzle 41 is set to be slower than the speed of the air curtain ejected from the first nozzle 31. This low-speed jet ejected from the second nozzle 41 flows along the jet of the air curtain ejected from the first nozzle 31. This makes it possible to suppress the entrained flow attracted by the jet of the air curtain in the suction side space, and to suppress the circulating vortex caused by the entrained flow. Therefore, by suppressing the circulating vortex, the flow fluctuation of the circulating vortex is reduced, and the stability of the jet of the air curtain is improved. This improves the reach and shielding properties of the air curtain, and further suppresses the scattering and diffusion of fumes H.

From the entrainment speed of the entrained flow by the air curtain and the spread angle of the jet, the entrainment flow speed from the suction side space and the surrounding space is about 1/5 to 1/6 of the flow speed of the jet of the air curtain. Therefore, if the low-speed jet flow speed emitted from the second nozzle 41 is equal to or lower than this flow speed, it is accelerated to the entrainment speed by the air curtain, and it has been found that the entrained flow by the air emitted from the second nozzle 41 does not occur. For this reason, the flow speed of the air emitted from the second nozzle 41 is set to 1/100 to 1/5 of the flow speed of the air curtain emitted from the first nozzle 31. Here, if the flow speed of the air emitted from the second nozzle 41 is less than 1/100 of the flow speed of the air curtain emitted from the first nozzle 31, the entrained flow cannot be sufficiently suppressed. Furthermore, if the flow rate of the air ejected from the second nozzle 41 is greater than 1/5 of the flow rate of the air curtain ejected from the first nozzle 31, the air ejected from the second nozzle 41 itself may induce an entrained flow. By setting the flow rate of the air ejected from the second nozzle 41 to 1/100 to 1/5 of the flow rate of the air curtain ejected from the first nozzle 31, the generation of an entrained flow can be effectively suppressed, and the scattering and diffusion of fumes H can be further suppressed.

The housing 10, the partition member 11, the suction hood 12, and the shielding member 13 are not limited to the above-mentioned configuration. FIG. 3 is a schematic front view showing a modified example of the exhaust device of the first embodiment. As shown in FIG. 3, the exhaust device 1A includes a housing 70, a partition member 71, a suction hood 72, and a shielding member 73. The housing 70 has a hollow rectangular tube shape, and a first opening 81 is provided on one side in the axial direction. The housing 70 has a plurality of casters (wheels) 82 attached to the lower part. The partition member 71 is disposed inside the housing 70, and has a second opening 84 provided inside the first opening 81 of the housing 70 with a first gap 83 therebetween. The partition member 71 has a rectangular tube shape of different diameters with a front end portion expanded to provide the second opening 84. The suction hood 72 is disposed inside the partition member 71, and a third opening 86 is provided inside the second opening 84 of the partition member 71 with a second gap 85 therebetween. The suction hood 12 has a rectangular cylindrical shape with a different diameter, with an expanded front end and a third opening 86.

The shielding member 73 is disposed inside the suction hood 72, and is provided with a third gap 87 inside the third opening 86 of the suction hood 72. The shielding member 73 has a square (rectangular) plate shape, and its outer periphery is connected to the tip of the suction hood 72 via multiple connecting members 88 (four in this embodiment).

Here, the first gap 83 formed by the housing 70 and the partition member 71 is provided along the circumferential direction of the first opening 81 and functions as an outlet (hereinafter referred to as the first outlet 83) for ejecting air (fluid). The second gap 85 formed by the partition member 71 and the suction hood 72 is provided along the circumferential direction of the second opening 84 and functions as an outlet (hereinafter referred to as the second outlet 85) for ejecting air (fluid). The third gap 87 formed by the suction hood 72 and the shielding member 73 is provided along the circumferential direction of the third opening 86 and functions as a suction port (hereinafter referred to as the suction port 87) for sucking outside air into the suction hood 72.

The configurations of the first blower fan 14A, the second blower fan 14B, the suction fan 15, etc. are the same as those described above. In addition, the shapes of the housing 10, 70, the partition member 11, 71, the suction hood 12, 72, and the shielding member 13, 73 are not limited to a cylinder or a square tube, but may be an ellipse, an oval, a rectangle, etc.

Next, the operation of the exhaust device 1 will be described. Figure 4 is a schematic diagram illustrating the air flow in the exhaust device of the first embodiment.

First, as shown in FIG. 1, the exhaust device 1 is moved to the opposite side of the work object 100 on which the fusing work is to be performed, and the housing 10, the partition member 11, the suction hood 12, and the shielding member 13 are positioned near the fumes H generated from the work object 100. In this state, the first blower fans 14A and the second blower fans 14B are driven, and the suction fan 15 is driven. Then, the outside air A1 is sucked from the first ducts 51A by the first blower fans 14A, and is supplied to the first space 52A between the housing 10 and the partition member 11, and then is blown out as an air curtain A2 from the first outlet 31. At this time, since the first outlet 31 is a throttle portion, the air supplied to the first space 52A is accelerated and blown out by the first outlet 31, forming an air curtain A2 with a uniform flow rate in the circumferential direction up to the source of the fumes H. This air curtain A2 is cylindrical in shape and flows toward the fumes H that are generated.

In addition, the outside air B1 is sucked from each second duct 51B by each second blower fan 14B, and is supplied to the second space 52B between the partition member 11 and the suction hood 12, and then is ejected from the second outlet 41 as the entrainment flow suppression air flow B2. At this time, since the second outlet 41 is a throttle portion, the air supplied to the second space 52B is accelerated and blown out by the second outlet 41, so that the entrainment flow suppression air flow B2 with a uniform flow rate in the circumferential direction along the air curtain A2 can be formed. This entrainment flow suppression air flow B2 is set to be 1/100 or more and 1/5 or less of the flow rate of the air curtain A2 ejected from the first outlet 31. The entrainment flow suppression air flow B2 ejected from the second outlet 41 has a cylindrical shape and flows inside the air curtain A ejected from the first outlet 31 along the jet of the air curtain A2. Therefore, as shown in FIG. 4, the entrained flow induced by the jet of the air curtain A2 in the suction side space can be suppressed, and the circulating vortex caused by the entrained flow can be suppressed.

The suction fan 15 also exerts a suction force on the inside of the suction hood 12 via the connecting duct 61. Then, a flow toward the suction hood 12 is generated inside the cylindrical air curtain A2 and the entrainment flow suppression air flow B2, and as shown in FIG. 4, the fumes H1 are sucked into the inside of the suction hood 12 from the suction port 45. At this time, since the suction port 45 is a throttle portion, the suction force inside the air curtain A2 is greater than that inside the suction hood 12, and the fumes H1 can be sucked into the inside of the suction hood 12 from the suction port 45.

At this time, the flow rate of the air curtain A2 sprayed from the first nozzle 31 is set to be faster than the flow rate of the fumes H1 sucked into the suction port 45. Therefore, by forming the air curtain A2 between the housing 10 and the source of the fumes H, the outside and inside of the air curtain A2 are separated, and the fumes H1 can be collected inside the suction hood 12 through the suction side space inside the air curtain A2. Then, the air curtain A2 sprayed from the first nozzle 31 returns together with the fumes H1 through the suction side space inside the air curtain A2 due to the suction force from the suction hood 12 near the source of the fumes H, and is collected inside the suction hood 12 through the suction port 45.

The fumes H1 sucked into the suction hood 12 through the suction port 45 then flow through the connecting duct 61 and the suction fan 15 to the exhaust duct 62, where dust and other foreign matter is removed by the filter 63 before being discharged to the outside as air.

The configuration described as a modified example of the exhaust device of the first embodiment also operates in a similar manner.

The exhaust device of the first embodiment thus includes a housing 10 having a first opening 21, a partition member 11 having a second opening 32 provided inside the housing 10 with a first gap (first outlet) 31 inside the first opening 21, a suction hood 12 having a third opening 42 provided inside the partition member 11 with a second gap (second outlet) 41, a shielding member 13 provided inside the suction hood 12 with a third gap (suction port) 45 inside the third opening 42, a first blower fan (fluid supply device) 14A and a second blower fan (fluid supply device) 14B that supply air into the housing 10, and a suction fan (suction device) 15 that draws air into the suction hood 12.

Therefore, when air is supplied into the housing 10 by the first blower fan 14A, air is ejected forward from the first outlet 31, and the ejected air forms an air curtain A2 toward the source of the fumes H. Also, when air is supplied into the partition member 11 by the second blower fan 14B, air is ejected from the second outlet 41 along the air curtain A, and the ejected air forms an entrainment flow suppression air flow B2 inside the air curtain A2. This entrainment flow suppression air flow B2 suppresses the generation of an entrainment flow induced by the jet of the air curtain A2, improving the stability of the jet of the air curtain. On the other hand, when the suction fan 15 sucks the inside of the suction hood 12, a suction force acts on the space in front from the suction port 45, and a flow of fumes H1 is generated from the source of the fumes H through the inside of the air curtain A2 toward the suction hood 12, and the fumes H1 are sucked into the suction hood 12 from the suction port 45. Therefore, even from a position far away from the source of fume H, the air curtain A2 can collect the fumes H1 without scattering or diffusing them, making it possible to efficiently collect the fumes H that are generated without interfering with processing operations.

In the exhaust device of the first embodiment, the first gap is provided as the first nozzle 31 along the circumferential direction of the first opening 21, and the second gap is provided as the second nozzle 41 along the circumferential direction of the second opening 32, and the flow speed of the air ejected from the second nozzle 41 is set to be slower than the flow speed of the air ejected from the first nozzle 31. Therefore, the low-speed jet ejected from the second nozzle 41 flows along the jet of the air curtain A2 ejected from the first nozzle 31, so that the entrainment flow induced by the jet of the air curtain A2 in the suction side space can be suppressed, and the circulating vortex caused by the entrainment flow can be suppressed. Therefore, by suppressing the circulating vortex, the flow fluctuation of the circulating vortex is reduced, and the stability of the jet of the air curtain A2 is improved. Therefore, the reach and shielding properties of the air curtain A2 are improved, and the scattering and diffusion of fumes H can be further suppressed.

In the exhaust device of the first embodiment, the flow velocity of the air ejected from the second nozzle 41 is set to 1/100 to 1/5 of the flow velocity of the air ejected from the first nozzle 31. Therefore, the generation of the entrained flow induced by the jet of the air curtain A2 can be effectively suppressed, improving the stability of the jet of the air curtain A2 and further suppressing the scattering and diffusion of fumes H.

In the exhaust device of the first embodiment, the third gap is provided as a suction port 45 along the circumferential direction of the third opening 42, so that the fumes H1 can be sucked in inside the air curtain A2 sprayed from the first nozzle 31, and the fumes H can be collected without scattering or diffusing.

In the exhaust device of the first embodiment, the suction fan 15 is connected to the suction hood 12 via a connecting duct 61, and a filter 63 is attached to the outlet of the suction fan 15. Therefore, foreign matter is removed from the fumes H1 sucked into the suction hood 12 by the filter 63, and the fumes can be discharged to the outside as purified air.

In the exhaust device of the first embodiment, the housing 10, the connecting duct 61, and the suction fan 15 are arranged in a horizontal direction, and at least the housing 10 is provided with movable casters 25. Therefore, by making part or all of the exhaust device 1 portable, versatility can be improved.

[Second embodiment]
5 is a schematic side view showing an exhaust device according to the second embodiment. Note that members having the same functions as those in the above-described embodiment are given the same reference numerals and detailed description thereof will be omitted.

In the second embodiment, as shown in FIG. 5, the exhaust device 110 includes a housing 10, a partition member 11, a suction hood 12, a shielding member 13, a circulation duct (fluid supply device) 111, and a suction fan 15. Here, the housing 10, the partition member 11, the suction hood 12, the shielding member 13, and the suction fan 15 are the same as those in the first embodiment, so a description thereof will be omitted.

The circulation duct 111 is bellows-shaped, so that it is expandable and foldable. One end of the circulation duct 111 is connected upstream of the outlet portion (filter 63) from the exhaust duct 62, and the other end is connected to the blocking portion 23 in the housing 10 that faces the second opening 32 of the partition member 11, and communicates with the second space portion 52B. The circulation duct 111 is provided with a filter 102 at the connection portion with the exhaust duct 62. This filter 102 may be omitted.

Therefore, when air is supplied into the housing 10 by the first blower fan 14A, the air is ejected forward from the first outlet 31, and the ejected air forms an air curtain A2 toward the source of the fumes H. On the other hand, when the suction fan 15 sucks the inside of the suction hood 12, a suction force acts on the space in front from the suction port 45, generating a flow of fumes H1 from the source of the fumes H through the inside of the air curtain A2 toward the suction hood 12, and the fumes H1 are sucked into the suction hood 12 from the suction port 45. The fumes H1 sucked into the inside from the suction port 45 of the suction hood 12 flow through the connecting duct 61 and the suction fan 15 to the exhaust duct 62, where dust and other foreign matter are removed by the filter 63 before being discharged as air to the outside.

In addition, a portion of the fumes H1 that flow from the suction hood 12 through the connecting duct 61 and the suction fan 15 to the exhaust duct 62 becomes air from which foreign matter has been removed by the filter 102, and is supplied to the second space 52B between the partition member 11 and the suction hood 12 through the circulation duct 111. Then, the air in the second space 52B is blown out from the second outlet 41 along the above-mentioned air curtain A2 as the entrainment flow suppression air flow B2. This entrainment flow suppression air flow B2 has a cylindrical shape and suppresses the generation of an entrainment flow induced by the jet of the air curtain A2, improving the stability of the jet of the air curtain A2. Therefore, the fumes H1 can be stably collected in the suction hood 12 through the space inside the air curtain A2. Then, near the source of the fumes H, the air curtain A2 and the entrainment flow suppression air flow B2 return inside the air curtain A2 together with the fumes H1 due to the suction force from the suction hood 12, and are collected inside the suction hood 12 through the suction port 45.

In this way, the exhaust device of the second embodiment is provided with a circulation duct 111 that branches off from the outlet of the suction fan 15 as a fluid supply device, and this circulation duct 111 is connected to the closing portion 23 of the housing 10 that faces the second opening 32 of the partition member 11.

As a result, the circulating flow of fumes H sucked in by the suction hood 12 can be ejected from the second ejection port 41 to form an entrained flow suppression air flow B2 that suppresses the generation of an entrained flow induced by the jet of the air curtain A2, and the stability and shielding of the air curtain A2 can be improved without increasing the processing flow rate in the downstream filter 63. This allows the entire system to be made more compact and energy-efficient.

[Third embodiment]
6 is a schematic diagram showing a main part of an exhaust device according to a third embodiment of the present invention. Note that members having the same functions as those in the above-described embodiments are given the same reference numerals and detailed description thereof will be omitted.

In the third embodiment, as shown in FIG. 6, the exhaust device 120 includes a housing 121, a partition member 11, a suction hood 12, a shielding member 13, a first blower fan (fluid supply device) 14A, a second blower fan (fluid supply device) 14B, and a suction fan (suction device, see FIG. 1) 15. Here, the partition member 11, the suction hood 12, the shielding member 13, the first blower fan 14A, the second blower fan 14B, and the suction fan 15 are the same as those in the first embodiment, so a description thereof will be omitted.

The housing 121 has a hollow cylindrical shape and is provided with a first opening 21 on one side in the axial direction. The housing 121 has a blocking portion 23 fixed integrally to one side in the axial direction of the cylindrical portion 22, and the first opening 21 is formed on the other side in the axial direction. The housing 121 is provided with a guide (guide member) 122 at the tip of the cylindrical portion 22. The cylindrical portion 22 has the same inner diameter along the axial direction, but the guide 122 has an expanding shape in which the inner diameter increases from the connection portion with the cylindrical portion 22 toward the front. The guide 122 is also provided continuously in the circumferential direction, like the cylindrical portion 22. Therefore, the first ejection port 31 is formed by this guide 122 and the tip of the conical portion 33 of the partition member 11, and can eject the air in the first space portion 52A in a diverging manner.

Therefore, the first blower fans 14A and the second blower fans 14B are driven, and the suction fan 15 (see FIG. 1) is also driven. Then, the outside air A1 is sucked in from the first ducts 51A by the first blower fans 14A and supplied to the first space 52A between the housing 10 and the partition member 11, and then sprayed out as an air curtain A2 from the first outlet 31. This air curtain A2 is sprayed out in a diverging manner by the guide 122, forming a cone shape.

In addition, the outside air B1 is sucked in from each second duct 51B by each second blower fan 14B, and is supplied to the second space 52B between the partition member 11 and the suction hood 12, and then is ejected from the second outlet 41 as an entrainment flow suppression air flow B2. The entrainment flow suppression air flow B2 flows along the air curtain A2, suppressing the generation of an entrainment flow induced by the jet of the air curtain A2, thereby improving the stability of the jet of the air curtain A2. In addition, the suction force of the suction fan 15 acts on the inside of the suction hood 12 through the connecting duct 61. Then, a flow toward the suction hood 12 is generated inside the conical air curtain A2, and the fumes H1 are sucked into the inside of the suction hood 12 from the suction port 45. That is, by forming a cone-shaped air curtain A2 between the housing 10 and the source of the fumes H, the outside and inside of the air curtain A2 are separated, and the fumes H1 can be collected inside the suction hood 12 through the space inside the air curtain A2. At this time, the air curtain A2 spreads in a cone shape toward the source of the fumes H, so the fumes H1 can be collected over a wide area.

The air curtain A2 ejected from the first ejection port 31 returns inside the air curtain A2 together with the fumes H1 due to the suction force from the suction hood 12 near the source of the fumes H, and is collected inside the suction hood 12 through the suction port 45. The fumes H1 sucked into the interior of the suction hood 12 through the suction port 45 of the suction hood 12 then flows through the connecting duct 61 and the suction fan 15 to the exhaust duct 62, where the filter 63 removes foreign matter such as dust and discharges the clean air to the outside.

In this way, the exhaust device of the third embodiment is provided with a guide 122 that ejects air from the first nozzle 31 in a divergent manner.

Therefore, air is sprayed from the first nozzle 31 through the guide 122 in a divergent direction toward the source of the fumes H, making it possible to collect the fumes H over a wide area.

In the above embodiment, the filter 63 is attached to the outlet of the suction fan 15, but the filter 63 may be attached to either the inlet or outlet side of the suction fan 15. Also, if the sucked air is discharged outdoors, the filter 63 may be omitted.

In addition, in the above-described embodiment, the housing, suction hood, shielding member, fluid supply device, and suction device are arranged horizontally and are movable, but this arrangement is not limited to this. For example, the housing, suction hood, shielding member, fluid supply device, and suction device may be arranged vertically and movable in both horizontal and vertical directions by a crane or the like.

As described above, the exhaust device of the present disclosure includes a housing having a first opening, a partition member having a second opening provided in the housing with a first gap inside the first opening, a suction hood having a third opening provided in the partition member with a second gap inside the second opening, a shielding member provided in the suction hood with a third gap inside the third opening, a fluid supply device that supplies fluid into the housing and the partition member, and a suction device that draws into the suction hood.

Therefore, when fluid is supplied into the housing by the fluid supply device, the fluid is ejected forward from the first gap between the housing and the partition member, and the ejected fluid forms a fluid curtain toward the source of the fumes. Also, when fluid is supplied into the partition member by the fluid supply device, the fluid is ejected from the second gap between the partition member and the suction hood onto the inside of the fluid curtain, and this fluid suppresses the generation of an entrained flow that is attracted to the jet of the curtain, improving the stability of the jet of the curtain. On the other hand, when the suction device sucks into the suction hood, a suction force acts on the space in front from the third gap between the suction hood and the shielding member, generating a flow of fumes from the source of the fumes toward the suction hood through the inside of the fluid curtain, and the fumes are sucked into the suction hood from the third gap. Therefore, the fumes can be collected without scattering or diffusing by the fluid curtain, and the fumes generated can be efficiently collected without interfering with the processing work.

In the exhaust device, the first gap and the second gap are provided along the circumferential direction of the first opening and the second opening, respectively, and function as a first outlet and a second outlet, respectively, for ejecting the fluid supplied by the fluid supply device, and the flow rate of the fluid ejected from the second outlet may be set to be slower than the flow rate of the fluid ejected from the first outlet.

The low-speed jet emitted from the second nozzle therefore flows along the curtain jet inside the curtain emitted from the first nozzle, making it possible to suppress the entrained flow attracted by the curtain jet in this inner space, and to suppress the circulating vortex caused by the entrained flow. As a result, the suppression of the circulating vortex reduces the flow fluctuation of the circulating vortex, improving the stability of the curtain jet. This improves the reach and shielding properties of the curtain, further suppressing the scattering and diffusion of fumes and making it possible to efficiently collect the fumes.

In the exhaust device, the flow velocity of the air ejected from the second nozzle may be set to 1/5 or less of the flow velocity of the air ejected from the first nozzle. This effectively prevents the generation of entrained flows induced by the curtain jet ejected from the first nozzle, improving the stability of the curtain jet. This further prevents the scattering and diffusion of fumes, making it possible to efficiently collect the fumes.

In the exhaust device, the third gap may be provided along the circumferential direction of the third opening, and may be configured to function as a suction port that draws outside air into the suction hood using the suction force of the suction device. Therefore, fumes can be sucked inside the curtain sprayed from the first nozzle, and the fumes can be collected without scattering or diffusing.

In the exhaust device, the first nozzle may be provided with a guide member that ejects the fluid in a divergent manner. Therefore, the guide member ejects the fluid from the nozzle in a divergent manner, allowing fumes to be collected over a wide area.

In the exhaust device, the suction hood may be connected to a suction device via a connecting duct at a position opposite the third opening, and a filter may be attached to the inlet or outlet side of the suction device. Therefore, by connecting the suction device to the suction hood via a connecting duct and attaching a filter to the inlet or outlet side of the suction device, foreign matter can be removed from the fumes sucked into the suction hood by the filter, and the fumes can be discharged to the outside as purified air.

In the exhaust device, a circulation duct branching off from the outlet of the suction device may be connected to a position facing the second opening in the housing as a fluid supply device. Therefore, by connecting the circulation duct branching off from the outlet of the suction device to the housing, the circulation flow of the sucked fumes can be ejected from the second gap to form a fluid flow that suppresses the generation of an entrained flow induced by the jet of the curtain, and the stability and shielding of the curtain can be improved without increasing the processing flow rate of the sucked fluid. This allows the entire system to be made more compact and energy-efficient.

In the exhaust device, the housing, the connecting duct, and the suction device are arranged along the horizontal direction, and at least the housing may be provided with movable wheels. Therefore, by making part or all of the exhaust device portable, versatility can be improved.

The exhaust method disclosed herein is an exhaust method using an exhaust device including a housing having a first opening, a partition member having a second opening provided in the housing with a first gap inside the first opening, a suction hood having a third opening provided in the partition member with a second gap inside the second opening, a shielding member provided in the suction hood with a third gap inside the third opening, a fluid supply device that supplies fluid to the housing and the partition member, respectively, and a suction device that sucks the inside of the suction hood, and includes the steps of: ejecting a first jet from the first gap; ejecting a second jet from the second gap along the first jet; and sucking the fluid from the third gap.

Therefore, when the fluid supply device supplies fluid into the housing, a first jet is jetted forward from a first gap between the housing and the partition member, forming a fluid curtain toward the source of the fumes. Also, when the fluid supply device supplies fluid into the partition member, a second jet is jetted from a second gap between the partition member and the suction hood onto the inside of the fluid curtain, and this second jet suppresses the generation of an entrained flow attracted by the jet of the curtain, improving the stability of the jet of the curtain. On the other hand, when the suction device sucks the inside of the suction hood, a suction force acts on the space in front from the third gap between the suction hood and the shielding member, generating a fume flow from the source of the fume through the inside of the fluid curtain toward the suction hood, and the fluid containing the fumes is sucked into the suction hood from the third gap. Therefore, the fumes can be collected without scattering or diffusing by the fluid curtain, and the fumes generated can be efficiently collected without interfering with the processing work.

Reference Signs List 1, 1A, 110, 120 Exhaust device 10, 70, 121 Housing 11, 71 Partition member 12, 72 Suction hood 13, 73 Shielding member 14A First blower fan (fluid supply device)
14B Second blower fan (fluid supply device)
15 Suction fan (suction device)
21, 81 First opening 25, 64, 65, 82 Caster (wheel)
31, 83 First jet outlet, first gap 32, 84 Second opening 41, 85 Second gap, second jet outlet 42, 86 Third opening 45, 87 Third gap, suction port 61 Connection duct 62 Exhaust duct 63, 102 Filter 111 Circulation duct (fluid supply device)
122 Guide (guide member)
A2 Air curtain (first jet)
B2 Entrainment flow suppression air flow (second jet)

Claims (7)

a housing having a first opening;
a partition member having a second opening provided inside the housing and on the inside of the first opening with a first gap therebetween;
a suction hood having a third opening provided inside the partition member and on the inside of the second opening with a second gap therebetween;
a shielding member provided inside the suction hood and on an inner side of the third opening with a third gap therebetween;
a fluid supply device that supplies fluid into the housing and the partition member,
A suction device that sucks air from inside the suction hood;
Equipped with
the first gap and the second gap are provided along a circumferential direction of the first opening and the second opening, respectively, and function as a first ejection port and a second ejection port that eject the fluid supplied by the fluid supply device,
An exhaust device , wherein a flow velocity of the fluid ejected from the second ejection port is set to 1/5 or less of a flow velocity of the fluid ejected from the first ejection port . The exhaust device according to claim 1 , wherein the third gap is provided along a circumferential direction of the third opening, and functions as a suction port that draws outside air into the suction hood by the suction force of the suction device. The exhaust device according to claim 1 or 2 , wherein the first ejection port is provided with a guide member for ejecting the fluid in a divergent manner. The exhaust device according to any one of claims 1 to 3 , wherein the suction hood is connected to the suction device via a connecting duct at a position opposite the third opening, and a filter is attached to an inlet side or an outlet side of the suction device. 5. The exhaust device according to claim 4 , wherein the fluid supply device is a circulation duct branched off from an outlet of the suction device and connected to a position facing the second opening in the housing. 6. The exhaust system according to claim 4 , wherein the housing, the connecting duct and the suction device are arranged along a horizontal direction, and at least the housing is provided with movable wheels. An exhaust method using an exhaust device including: a housing having a first opening; a partition member having a second opening provided in the housing with a first gap inside the first opening; a suction hood having a third opening provided in the partition member with a second gap inside the second opening; a shielding member provided in the suction hood with a third gap inside the third opening; a fluid supply device that supplies fluids into the housing and the partition member, respectively; and a suction device that sucks inside the suction hood,
ejecting a first jet from the first gap;
ejecting a second jet from the second gap along the first jet;
and sucking the fluid from the third gap ,
A method for exhausting , comprising the steps of: setting a flow velocity at which the second jet is ejected to 1/5 or less of a flow velocity at which the first jet is ejected .

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