JP7779165B2 - Microparticle removal device and removal method - Google Patents

Description

The present invention relates to a device and method for removing fine particles.

Generally, various types of workpiece processing equipment require a mechanism to exhaust particles generated during workpiece processing, such as spatter and fumes generated during laser processing, to the outside of the equipment so as not to interfere with the operation of the processing equipment.

Patent Document 1 discloses a laser scriber equipped with a gas injection device that injects gas into the space between the ceramic substrate and the laser focusing lens, which is the space through which the laser irradiated toward the ceramic substrate passes when cutting the ceramic substrate with a laser. The document states that the gas injection device prevents contamination of the laser focusing lens by droplets generated when cutting the workpiece.

Japanese Patent Application Publication No. 11-58050

In the laser scriber described in Patent Document 1 above, a gas injection device is used to prevent droplet contamination of the lens that occurs when cutting the workpiece. However, in addition to lens contamination, there is also a need to efficiently and reliably exhaust to the outside of the hood, not only fumes adhering to the workpiece (workpiece), such as a ceramic substrate, and fine particles such as spatter scattered on the inside of the hood, from the inside of the cover member (hood) that covers the workpiece (workpiece).

Conventionally available particle removal devices include those that use a negative pressure suction source to create negative pressure inside the hood, while also injecting air into the hood to expel and remove particles present inside the hood. However, with this type of device, turbulence can occur in the airflow in various places inside the hood, which can prevent particles from being properly removed and may result in insufficient particle removal.

The present invention was made in consideration of the above-mentioned circumstances, and the problem that the present invention aims to solve is to provide a particulate removal device and removal method that can efficiently and reliably discharge particulates.

In order to solve the above problems, the present invention employs the following means.
That is, one aspect of the present invention is a particulate removal device that removes particulates present in a hood using gas. This removal device includes an injection mechanism that injects gas into the hood, a Coanda flow generator that generates a Coanda flow in the gas injected into the hood, and a main flow path that transports the particulates using the gas flow controlled by the Coanda flow generator.
According to the present invention, a gas flow caused by the Coanda effect (hereinafter referred to as the Coanda flow in this paper) is generated in the gas, and the fine particles are transported by the controlled gas flow, so that the fine particles can be discharged efficiently and reliably.

In one aspect of the present invention, the hood includes a guide member and a first member. Here, the guide member has a first guide wall surface and a second guide wall surface. The gas flowing along the first guide wall surface is controlled by the Coanda flow on the second guide wall surface, and the controlled gas transports the fine particles. The first guide wall surface guides the injected gas to flow along it. The second guide wall surface is bent and inclined from the first guide wall surface with respect to the direction in which the gas is guided, and constitutes a first Coanda flow generating unit as a Coanda flow generating unit. The first member is located forward of the tip of the second guide wall surface, and the fine particles are attached to it.
In this embodiment, the gas is guided along the first guide wall surface, and the gas flow is guided to the particles by the Coanda flow generated by the second guide wall surface that constitutes the Coanda flow generating section that is continuous with this, and the particles are transported, so that a gas flow can be generated at the targeted particles to transport them reliably.

In one aspect of the present invention, the hood has a first opening on one side of an area where fine particles float or adhere, a second opening on the other side, and a third opening on an axis intersecting a direction from the first opening to the second opening. The injection mechanism is arranged so that the gas it injects transports the fine particles in the area toward the second opening. A negative pressure suction source is provided on the side of the second opening to create negative pressure inside the hood. On the inner wall surface of the hood, between the third opening and the second opening, a second Coanda flow generating portion is formed, consisting of a curved surface that generates a Coanda flow in the gas flowing in from the third opening using the negative pressure suction source.
In this embodiment, a third opening is provided, which is located on an axis that intersects with the direction from the first opening to the second opening. A curved surface is formed between the third opening and the second opening, which causes a Coanda flow in the gas flowing in from the third opening. By causing a Coanda flow in the gas flow within the hood, a smooth gas flow without turbulence is generated, and fine particles can be transported efficiently.

In one aspect of the present invention, the injection mechanism has an injection port formed in a slit shape for injecting gas.
In this embodiment, the injection port is formed in a slit shape, so that it is possible to select an injection port shape that is appropriate for generating a Coanda flow.

In one aspect of the present invention, the second guide wall surface has an angle in the range of 20 degrees to 40 degrees with respect to the surface to which the fine particles adhere.
In this aspect, the angle of the second guide wall surface serving as the Coanda flow generating portion is set within a suitable range.

In one aspect of the present invention, the injection mechanism includes an injection wall portion having an injection port at its tip. The injection wall portion includes a first flow path and a second flow path. The first flow path guides compressed air toward the injection port. The second flow path communicates with the first flow path, and a third Coanda flow generating portion is formed, the third Coanda flow generating portion having a curved wall surface in part, that generates a Coanda flow toward the injection port.
In this aspect, the injection mechanism is provided with a second flow path in which a third Coanda flow generating portion, part of which is made of a curved wall surface that generates a Coanda flow toward the injection port, is formed, so that the gas flow from the injection port can be controlled in the desired direction by the curved wall surface.

In one embodiment of the present invention, the particulates include fumes or spatters generated when a workpiece is processed by laser.
According to this aspect, the particulate removal device can reliably remove spatters and fumes that are difficult to remove.

In one aspect of the present invention, the injection mechanism is positioned so that its injection port is injected obliquely toward the surface of the workpiece held in a horizontal position.
In this embodiment, the gas ejection nozzle is positioned so that the gas is ejected obliquely toward the surface of the workpiece held in a horizontal position, thereby generating a gas flow suitable for removing fine particles.

Another aspect of the present invention is a method for removing particulates, which comprises injecting gas into a hood to generate a Coanda flow, and removing the particulates with the gas flow including the Coanda flow.
According to the method for removing particulates of another aspect of the present invention, the Coanda flow is utilized, so that the particulates can be discharged efficiently and reliably.

In one aspect of the present invention, when removing fine particles present in a hood with gas, gas is injected into the hood and the gas flow generates a Coanda flow along the surface on which the fine particles are present, and the fine particles are then transported by the gas flow including the Coanda flow.
In this embodiment, a Coanda flow is generated along the surface on which the fine particles are present, and the fine particles are transported by a gas flow including this Coanda flow, so that the gas flow can be controlled by reliably targeting the position where the fine particles are present.

In one aspect of the present invention, when removing fine particles present inside a hood with gas, gas is injected into the hood to generate a Coanda flow along the inner surface of the hood, and the fine particles are transported by the gas flow including the Coanda flow.
In this embodiment, a Coanda flow is generated along the inner surface of the hood, so that a smooth gas flow is generated without generating turbulence inside the hood, and fine particles can be transported efficiently.

The present invention provides a particulate removal device and method that can efficiently and reliably discharge particulates.

1 is a cross-sectional view of a particulate removal device according to an embodiment of the present invention. 1 is an enlarged cross-sectional view of a main part of a particulate removal device according to an embodiment of the present invention. 1 is a cross-sectional view of a particulate removal device according to an embodiment of the present invention. 1 is a perspective view of a spray mechanism of a particulate removal device according to an embodiment of the present invention. 1 is a cross-sectional view of a spray mechanism of a particulate removal device according to an embodiment of the present invention. 1 is a cross-sectional view of a laser processing device according to an embodiment of the present invention. FIG. 7 is an enlarged view of a main part of FIG. 6.

(Embodiment)
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the accompanying drawings. Fig. 1 is a cross-sectional view showing a particulate removal device according to an embodiment of the present invention.
As shown in FIG. 1, the particle removal device 10 includes an injection mechanism 5 and a hood 7. A first member 17 having a surface 17a is disposed in the main flow path R within the hood 7. FIG. 2 is an enlarged view of the first member 17. As shown in FIG. 2, a first guide member 16 having a first guide wall surface 13 and a second guide wall surface 15, and a second guide member 22 having a third guide wall surface 19 and a fourth guide wall surface 21 are disposed on the first member 17. The first guide member 16 and the second guide member 22 are disposed on both sides of the surface 17a. The particle removal device 10 is a device for removing particle B, which is assumed to be adhered to the surface 17a.

The gas (arrow a3) injected from the injection mechanism 5 flows along the first guide wall surface 13 (arrow a4). The second guide wall surface 15 is bent and inclined from the first guide wall surface 13 in the direction in which the gas flows (arrow a4), constituting a first Coanda flow generating portion 11a. The surface 17a of the first member 17 is positioned as a surface continuous with the second guide wall surface 15. The third guide wall surface 19 is positioned as an inclined surface continuous with the surface 17a. The fourth guide wall surface 21 is bent and inclined from the third guide wall surface 19 in the direction in which the gas flows (arrow a6), constituting a fourth Coanda flow generating portion 11d. The second guide wall surface 15 and the third guide wall surface 19 are angled at an angle ranging from 20 to 40 degrees with respect to the surface 17a to which the fine particles adhere.

Figure 3 is a cross-sectional view of the hood 7 in the particulate removal device 10 of this embodiment. In Figure 3, in order to particularly explain the hood 7, the spray mechanism 5 is depicted in a simplified form, and the first guide member 16 and second guide member 22 on the first member 17 are shown absent. The hood 7 in this embodiment has a first opening 23 on one side and a second opening 25 on the other side, sandwiching the surface 17a to which particulates adhere, as well as a third opening 27 on an axis j2 that intersects with the direction j1 from the first opening 23 to the second opening 25. The spray mechanism 5 is positioned so that the gas it sprays transports particulates on the surface 17a toward the second opening 25, and a negative pressure suction source 19 that creates negative pressure within the hood 7 is provided on the second opening 25 side. On the inner wall surface of the hood 7, between the third opening 27 and the second opening 25, a second Coanda flow generating portion 11b is formed, which consists of a curved surface 29 that generates Coanda flows b2 and b3 in the gas flowing in from the third opening by the negative pressure suction source 19.

Figure 4 is a simplified perspective view of the injection mechanism 5 of this embodiment. As shown in Figure 4, the injection mechanism 5 has a gas supply source 5b that supplies gas connected to a supply pipe 5c, and the injection port 5a that injects the gas is formed in a slit shape. Figure 5 is a cross-sectional view of the injection mechanism 5 of this embodiment. The injection mechanism 5 has an injection wall portion 31 with an injection port 5a at its tip. Within the injection wall portion 31 are a first flow path 33 that guides gas toward the injection port 5a, and a second flow path 35 that communicates with the first flow path 33 and has a third Coanda flow generating portion 11c formed therein, the third Coanda flow generating portion 11c having a curved wall surface 37 in part that generates a Coanda flow toward the injection port 5a.

Next, the operation of the particulate removal device 10 configured as described above will be described. As shown in FIG. 1, compressed gas is supplied from the gas supply source 5b through the supply pipe 5c to the injection mechanism 5 (arrow a1). The gas used at this time may be air or an inert gas such as nitrogen or argon. As shown in FIG. 5, the gas supplied to the supply pipe 5c is guided from the first flow path 33 to the second flow path 35 (arrow a2). The second flow path 35 has a curved wall surface 37 that constitutes the third Coanda flow generating portion 11c, and the gas is injected from the injection port 5a along this curved wall surface 37 (arrow a3).

As shown in Figure 2, the gas (arrow a3) injected from the injection port 5a flows along the first guide wall surface 13 (arrow a4). Beyond the first guide wall surface is the second guide wall surface 15, which forms the first Coanda flow generating portion 11a and is bent and inclined relative to the first guide wall surface 13. Due to the Coanda effect, the gas flow flows along the second guide wall surface 15 (arrow a5). The gas flow guided along the second guide wall surface blows away the fine particles B on the surface 17a (Figure 1).

As shown in FIG. 2, the gas flow passing over surface 17a collides with the inclined third guide wall surface 19 ahead, and its direction is changed to follow the inclination of third guide wall surface 19 (arrow a6). Ahead of third guide wall surface 19, a fourth guide wall surface 21 is formed, bending and inclining from third guide wall surface 19. Fourth guide wall surface 21 constitutes fourth Coanda flow generating portion 11d. The gas flow (arrow a6) flowing along third guide wall surface 19 is changed in direction to follow fourth guide wall surface 21 due to the Coanda effect (arrow a7).

As shown in FIG. 1, a negative pressure suction source 19 that creates negative pressure suction inside the hood 7 is provided on the side of the second opening 25 of the hood 7. A curved surface 29 is formed on the inner wall between the third opening 27 and the second opening 25. The gas flow (arrow b1) sucked from the third opening 27 by the negative pressure suction source 19 flows in a direction along this curved surface 29 (arrows b2 and b3) due to the Coanda effect of this curved surface 29 that constitutes the second Coanda flow generating portion 11b. The Coanda flow a8 containing the fine particles B that have been blown away and the Coanda flow b3 from the third opening 27 merge at the second opening 25 and are sucked into the negative pressure suction source 19 (arrow a9).

As described above, in the particulate removal device 10 according to this embodiment, the direction of the gas injected from the injection port 5a of the injection mechanism 5 is determined by the curved wall portion 37 that constitutes the third Coanda flow generating portion 11c, making it easy to determine the direction of the gas flow for transporting particulate B. Furthermore, because the injection port 5a is formed in a slit shape, it is suitable for generating a gas flow due to the Coanda effect. Furthermore, because it is slit-shaped, it is possible to generate a uniform injection flow in the width direction.

The first Coanda flow generator 11a controls the gas flow from the nozzle 5a so that it flows along the surface of the surface 17a all the way to the fine particles B, ensuring reliable transport of the fine particles B. The fourth Coanda flow generator 11d redirects the gas flow toward the second opening 25, where the negative pressure suction source 19 is located. Furthermore, a third opening 27 is provided, and the air flow from the third opening is redirected toward the second opening 25 by the second Coanda flow generator, which uses a curved surface 29 between the third opening 27 and the second opening 25. Therefore, the gas flows are both directed toward the second opening 25 without causing stagnation or turbulence within the hood 7. This allows for efficient transport of fine particles with a small airflow volume without unnecessarily increasing the negative pressure of the negative pressure suction source. Therefore, it is possible to provide a particulate removal device 10 and method that can efficiently and reliably transport and discharge the particulate B using a gas flow controlled by the Coanda flow generating units 11a, 11b, 11c, and 11d.

An example of the fine powder that can be removed by the above-described embodiment is fine powder generated by laser processing. The removal of fine particles generated by a laser processing device will be described below.
Figure 6 is a cross-sectional view of a laser processing apparatus 20 equipped with a particulate removal device. This apparatus differs from the apparatuses of Figures 1 to 5 in that a laser irradiation device 2 is provided that irradiates a laser onto surface 17a to process first member 17. Laser irradiation processing by laser irradiation device 2 generates fumes, spatter, and the like as particulates B on surface 17a. The structure and operation of other Coanda flow generating units 11a to 11d are the same as those of the apparatuses of Figures 1 to 5, and with the same operational effects as those of the apparatuses of Figures 1 to 5, particulates B such as fumes and spatter generated by laser processing can be efficiently and reliably transported and discharged.

Fig. 7 is an enlarged view of the main part of Fig. 6. Hereinafter, the removal of particles generated by laser processing will be described in more detail with reference to Figs.
As shown in FIG. 6, the laser processing apparatus 20 equipped with a particulate removal device includes a laser irradiation device 102 that irradiates a laser onto a workpiece 104, a holding member 103 that holds the workpiece 104, an injection mechanism 105 that injects gas toward the holding member 103, a hood 107 that covers the workpiece, and a transport mechanism 108 that transports the holding member 103 holding the workpiece 104 into the hood 107.

As shown in Figure 7, the holding member 103 has a first guide surface 103a provided in front of the laser irradiation section 102a for the workpiece 104, and the injection mechanism 105 is positioned so that its injection port 105a injects gas obliquely relative to the first guide surface 103a, and so that the gas flows from in front of the laser irradiation section 102a on the workpiece 104 to in front of the laser irradiation section 102a.

As shown in FIG. 6, the hood 107 has a first opening 107c on one side and a second opening 107b on the other side. It also has a third opening 107a on an axis intersecting the direction from the first opening 107c to the second opening 107b. A holding member 103 holding a workpiece 104 is transported by a transport mechanism 108 and placed on the side of the first opening 107c. The laser irradiation device 102 and the injection mechanism 105 are located on the side of the first opening 107c. A negative pressure suction source 19 is provided on the side of the second opening 107b. Specifically, the negative pressure suction source 19 is a dust collection device or the like.

As shown in FIG. 6, the holding member 103 is formed with an exposed portion 103b where the workpiece 104 is laser processed, and a covered portion 103c that is covered by the holding member 103. As shown in FIG. 7, the injection port 105a is positioned facing the covered portion 103c, and the covered portion 103c of the holding member 103 is provided with a second guide wall surface 103d that guides gas from the injection port 105a toward the laser irradiation portion 102a by the Coanda effect. Here, the first guide wall surface 103a is part of the covered portion 103c, and the laser irradiation portion 102a is part of the exposed portion 103b. The second guide wall surface 103d is angled at an angle ranging from 20 to 40 degrees with respect to the surface of the workpiece 104 that is laser irradiated.

Next, the operation of the laser processing apparatus 20 configured as described above will be described. First, the workpiece 104 is held by the holding member 103 shown in FIG. 6. The holding member 103 holding the workpiece 104 is transported into the first opening 107c by the transport mechanism 108. At this time, the dust collector, which is the negative pressure suction source 19, sucks air through the second opening 107b. The gas supply source 105b supplies gas to the supply pipe 105c, and the gas is sprayed from the nozzle 105a. Once the workpiece 104 is placed in a predetermined position, the laser L is irradiated onto the workpiece 104 from the laser irradiation device 102, as shown in FIG. 6, and laser processing of the workpiece 104 is performed.

As shown in Figure 7, a laser L is irradiated onto the laser irradiation unit 102a, and laser processing is performed on the workpiece 104. The illustration shows spatters (s) scattered during laser processing. As shown in Figure 6, a negative pressure suction source 19 is connected to the second opening 107b of the hood 107, and air outside the hood 107 is sucked in as indicated by arrow f1 at the third opening 107a and arrow f3 at the first opening 107c, creating a gas flow indicated by arrow f4 inside the hood 107. Multiple spatters (s) scattered during laser processing collide with the inner wall of the hood 107. Because of their high elasticity, the colliding spatters (s) do not adhere to the inner wall of the hood 107, but instead bounce off the wall, losing their energy as they travel in a straight line. The energy-losing spatters (s) are sucked into the gas flow f4 inside the hood 107 and collected in the dust collector, which is the negative pressure suction source 19.

As shown in Figure 7, when laser processing is being performed, gas is injected from the injection port 105a at an angle toward the first guide wall surface 103a, as indicated by arrow c1. The gas injected in this manner flows from the first guide wall surface 103a along the surface of the second guide wall surface 103d (arrow c2), then passes through the laser irradiation section 102a (arrow c3), forming a gas flow into the hood 107 (arrow c4). The gas flow in the directions indicated by arrows c1 to c4 is a phenomenon caused by the Coanda effect. Here, the Coanda effect refers to the phenomenon where, when a gas jet hits a wall surface, the gas flow flowing along that surface is attracted to nearby wall surfaces and flows along the wall surface. In this embodiment, gas injected obliquely onto the surface of the coated portion 103c of the holding member 103 flows along that surface (arrow c1), is attracted to the second guide wall surface 103d (arrow c2), and generates a gas flow that licks the surface of the workpiece 104 in the laser irradiation section 102a from the side perpendicular to the laser L (arrow c3), which merges with the gas flow inside the hood 107 (gas flow f4 in Figure 7) (arrow c4). These gas flows c1 to c4 allow fumes and other substances generated in the laser irradiation section 102a to be removed from the workpiece 104 and collected.

As described above, in this embodiment, the injection port 105a of the injection mechanism 105 is positioned so that the gas flows from in front of the laser irradiation section 102a of the workpiece 104 to in front of the laser irradiation section 102a, thereby reliably removing spatter and fumes generated during laser processing from the workpiece 104.

The gas flow that flows from in front of the laser irradiation area 102a on the workpiece 104 to in front of the laser irradiation area 102a is generated by the Coanda effect, so the gas flows c1 to c4 that flow along the surface of the laser processing point on the workpiece 104 efficiently remove fumes from the surface of the laser processing point during laser processing and merge with the above-mentioned gas flow f4 inside the hood 107, ensuring reliable fumes removal.

Once spatters and other particles scattered by the laser processing device 20 adhere to the workpiece 104, they are so adhesive that they are difficult to remove using only the suction of the hood 107. However, the gas flow near the processing point due to the Coanda effect not only removes the attached fumes, but also forcibly blows away spatters and dust generated within the hood away from the processing point, preventing them from adhering.

In addition, a hood 107 is provided that covers the laser irradiation area 102a, which is the processing point of the workpiece 104. Spatters scattered during laser processing can be collided with the inner wall of the hood 107, thereby attenuating the energy of the spatters s. The hood 107 generates a gas flow f4 that is sucked in by the negative pressure suction source 19 from the second opening 107b. This energy-attenuated spatters s can then be easily sucked into the dust collector, which is the negative pressure suction source 19, along with the gas flow f4. In other words, extremely high-velocity spatters s with sizes ranging from several microns to several hundred microns, which are difficult to suck in using only the negative pressure of the negative pressure suction source 19, can be sucked in by utilizing collisions with the inner wall of the hood 107 to attenuate the energy of the spatters s to a level that allows them to be sucked in.

The first opening 107c provided in the hood 107 allows the workpieces 104 to be continuously transported and processed within the hood 107, making it easily adaptable to mass production lines. Because the hood 107 covers the workpieces 104 from above and below, dust generated within the hood 107 can be reliably sucked in.

In this embodiment, the second guide wall surface 103d of the holding member 103 is used to guide the gas flow to the laser irradiation portion 102a by the Coanda effect, but this is not limited to this. For example, the gas flow may be guided to the laser irradiation portion using a concave or convex curved surface, or, depending on how the workpiece is held, the gas may be injected directly in front of the laser irradiation portion 102a of the workpiece 104. The shape of the workpiece is not limited to a flat plate, and may also be one that is machined into a curved surface. In other words, the gas may be injected so as to guide the gas flow to the laser irradiation portion by the Coanda effect, taking into account the shape of the workpiece and the shape of the machined surface. The shape of the injection port 105a is not limited to a linear slit, and may be a curved slit taking into account the surface shape of the workpiece 104. Furthermore, any shape that effectively generates a gas flow by the Coanda effect on the surface of the workpiece 104 may be used, without being limited to a slit.

10 Fine particle removal device 5, 105 Injection mechanism 7, 107 Hood 11a First Coanda flow generating section 11b Second Coanda flow generating section 11c Third Coanda flow generating section 13, 103a First guide wall surface 15, 103d Second guide wall surface 17 First member 19 Negative pressure suction source 23, 107c First opening 25, 107b Second opening 27, 107a Third opening 29 Curved surface 31 Injection wall portion 33 First flow path 35 Second flow path 37 Curved wall surface 20, Laser processing device 2, 102 Laser irradiation device 102a Laser irradiation portion 103 Holding member 103b Exposed portion 103c Covered portion 104 Workpiece 105a Injection port B Fine particle j1 Direction j2 from the first opening toward the second opening rear portion Intersecting axis R Main flow path

Claims (9)

A particle removal device that removes particles present in a hood using gas,
an injection mechanism that injects gas into the hood;
a Coanda flow generating unit that generates a Coanda flow in the gas injected into the hood;
a main flow path that transports the fine particles by a gas flow controlled by the Coanda flow generating unit ,
Within the hood,
a guide member having a first guide wall surface along which the injected gas flows, and a second guide wall surface that is bent and inclined from the first guide wall surface with respect to the direction along which the gas flows, and that constitutes a first Coanda flow generating portion as the Coanda flow generating portion;
a first member to which the fine particles adhere, the first member being located in front of the tip of the second guide wall surface;
A particulate removal device, wherein gas flowing along the first guide wall surface is controlled by a Coanda flow on the second guide wall surface, and the particulates are transported by this controlled gas . A particle removal device that removes particles present in a hood using gas,
an injection mechanism that injects gas into the hood;
a Coanda flow generating unit that generates a Coanda flow in the gas injected into the hood;
a main flow path that transports the fine particles by a gas flow controlled by the Coanda flow generating unit,
the hood has a first opening on one side of an area where the fine particles float or adhere, a second opening on the other side thereof, and a third opening on an axis intersecting a direction from the first opening to the second opening;
the injection mechanism is disposed so as to transport the fine particles in the region toward the second opening by the gas injected by the injection mechanism;
a negative pressure suction source that creates negative pressure inside the hood is provided on the second opening side;
On the inner wall surface of the hood, between the third opening and the second opening, a second Coanda flow generating portion consisting of a curved surface that generates a Coanda flow in the gas flowing in from the third opening by the negative pressure suction source is formed . A particulate removal device. Within the hood,
a guide member having a first guide wall surface along which the injected gas flows, and a second guide wall surface that is bent and inclined from the first guide wall surface with respect to the direction along which the gas flows, and that constitutes a first Coanda flow generating portion as the Coanda flow generating portion;
a first member to which the fine particles adhere, the first member being located in front of the tip of the second guide wall surface;
3. The device for removing fine particles according to claim 2, wherein the gas flowing along the first guide wall surface is controlled by a Coanda flow on the second guide wall surface, and the fine particles are transported by this controlled gas. The particulate removal device according to any one of claims 1 to 3, wherein the injection mechanism has a slit-shaped injection port for injecting gas. The second guide wall surface, which is bent and inclined relative to the direction in which the injected gas is guided from the first guide wall surface to the gas along the first Coanda flow generating unit as the Coanda flow generating unit , has an angle in the range of 20 degrees to 40 degrees with respect to the surface to which the particles adhere, according to any one of claims 1 to 4. The injection mechanism comprises an injection wall portion having an injection port at a tip for injecting the gas , and the injection wall portion includes a first flow path for guiding compressed air toward the injection port, and a second flow path connected to the first flow path, the second flow path having a third Coanda flow generating portion formed therein, the third Coanda flow generating portion having a curved wall surface, the third Coanda flow generating portion being formed in part of the curved wall surface, and configured to generate a Coanda flow toward the injection port. The particulate removal device according to claim 4 or 5. A particulate removal device according to any one of claims 1 to 6, wherein the particulates include fumes or spatter generated when laser processing a workpiece. 8. The particulate removal device according to claim 7, wherein the injection mechanism has an injection port for injecting the gas positioned so that the gas is injected obliquely toward the surface of the workpiece held in a horizontal position. A method for removing particles present in a hood using a gas, comprising:
a gas is injected into the hood to generate a Coanda flow, and the particulate matter is removed by the gas flow including the Coanda flow ;
When removing the fine particles present in the hood with gas, the gas is injected into the hood to generate a Coanda flow along the surface on which the fine particles are present, and the fine particles are transported by the gas flow including the Coanda flow;
The method for removing fine particles , wherein the surface on which the fine particles exist is the inner surface of the hood .