Suction device

Abstract

To provide a suction device that stably forms an air curtain for enclosing a wide range, can efficiently suck the enclosed range by a tornado flow, and has excellent manufacturing easiness and designability.SOLUTION: A suction device for performing local exhaust includes: a suction flow passage 10 that has a suction port in the end in a direction of a suction object 90 and allows a suction flow to flow; a suction fan 20 for generating a suction flow in the suction flow passage 10; a blow-off flow generation chamber 30 for introducing a blow-off flow from an inlet in a side opposite to the suction object 90 and expanding it in a disk shape; multiple blow-off fans 40 for blowing off the blow-off flow in an outer direction whirled round with the axis of the suction flow passage 10 as a center from the blow-off flow generation chamber 30; and a blow-off flow deflection guide 50 for deflecting a blow-off flow blown off by the multiple blow-off fans 40 in a direction of the suction object 90.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fan that is made up of a plurality of fans and that forcibly draws in local air. [Background technology]

[0002] Conventionally, suction devices for local exhaust have been proposed. For example, the device in Patent Document 1 uses a coaxial double-structure propeller fan with blades arranged to generate a blowing flow on the outer side and a suction flow on the inner side, generating a blowing flow on the outer side to form an air curtain while sucking in the air inside with the inner side. As the propeller fan rotates, the blowing flow and the suction flow rotate in the same direction, generating a tornado flow and achieving effective suction.

[0003] The device in Patent Document 2 uses two sirocco fans, one of which blows air from the periphery to generate an air curtain, while the other fan draws air from the center. At this time, inclined blades are provided midway along the blown air path to swirl the blown air, thereby generating a tornado flow.

[0004] On the other hand, the device of Patent Document 3, as shown in Figure 9 (a modified version of Figure 6 in Patent Document 3), uses a fan array consisting of multiple blow-out fans 230 arranged on a circumference surrounding the suction fan 210, forming a large-diameter cylindrical air curtain that can surround the object to be suctioned from the start. Each blow-out fan 230 is an axial flow fan, and its rotation axis is arranged in a twisted direction relative to the rotation axis of the suction fan 210, causing the air curtain to swirl. This swirl generates a tornado flow in the suction flow. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 5-60088 [Patent Document 2] Japanese Patent Application Publication No. 8-75208 [Patent Document 3] Patent No. 6973796 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the suction devices described in Patent Documents 1 and 2, the blown airflow is spread into a skirt shape by a guide to form an air curtain that encloses a wide area, which weakens the swirl of the blown airflow, and as a result, there is a concern that the swirl of the suction airflow formed by the reversal of the blown airflow, i.e., the tornado airflow, will also be weak. Furthermore, if the swirl of the blown airflow is weak, the blown airflow will quickly diffuse, which raises the concern that the air curtain will not be able to be formed stably.

[0007] In the suction device described in Patent Document 3, the multiple blowing fans that make up the fan array are all twisted in the same direction around the suction axis in order to achieve a stable air curtain and a tornado-like suction flow. However, to achieve this, each fan needs to be tilted significantly, which poses some problems in terms of ease of manufacturing and product design.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a suction device that can stably form an air curtain that encloses a wide area, efficiently suck in the enclosed area with a tornado flow, and is easy to manufacture and has excellent design. [Means for solving the problem]

[0009] In order to solve the above problem, a suction device according to a first aspect of the present invention comprises: A suction device for performing local exhaust, a suction flow passage having a substantially circular suction port at an end portion facing the suction target and through which a suction flow flows; a suction fan that generates the suction flow in the suction flow passage; an outlet flow generating chamber formed in a substantially circular plate shape coaxially surrounding the suction flow passage, into which an outlet flow is introduced from an inlet on the opposite side to the suction target and spreads in a circular plate shape; a plurality of blowout fans provided at respective locations on the outer periphery of the blowout flow generating chamber, the blowout fans blowing the blowout flow from the blowout flow generating chamber in an outward direction revolving around the axis of the suction flow passage; The air conditioner is characterized by comprising an outlet flow deflection guide that is provided on the outer periphery of the outlet flow generation chamber and deflects the outlet flows blown out by the plurality of outlet fans toward the suction target.

[0010] The suction device may further include an outlet flow straightening guide, which comprises an outer guide extending the tip of the outlet flow deflection guide and an inner guide provided along the outer periphery of the outlet flow generating chamber, for straightening the outlet flow.

[0011] A suction device according to a second aspect of the present invention is a suction device for performing local exhaust, a suction flow passage having a substantially circular suction port at an end portion facing the suction target and through which a suction flow flows; a suction fan that generates the suction flow in the suction flow passage; a blowout fan consisting of a plurality of axial flow fans arranged on a substantial circumference surrounding the suction flow passage in a plane perpendicular to the axis of the suction flow passage, with the rotation axes being parallel to the axis of the suction flow passage, and generating a blowout flow; and a blowout flow swirl guide for swirling the blowout flow from each of the blowout fans around the axis of the suction flow passage.

[0012] The outlet flow swirl guide may be formed as an independent hood for each of the outlet fans, and may be configured so that the mounting angle can be adjusted independently.

[0013] Each of the hoods may have an air outlet formed as a long hole in the direction of the rotation axis of the suction fan, so that when the airflows from each of the hoods are combined, an approximately cylindrical air curtain can be formed without any gaps.

[0014] Each of the suction devices may further include a rotation control unit that controls the rotation speed of the suction fan and each of the blowing fans individually. [Effects of the Invention]

[0015] The suction device of the present invention uses multiple blow-out fans arranged around the suction fan and a guide to direct the blow-out flow, so it can form a large air curtain with sufficient blow-out speed and swirling speed, and can surround the object to be suctioned and efficiently suck it in with a tornado flow.

[0016] Of these, the suction device according to the first aspect uses multiple blow-out fans to form an outward blow-out flow that rotates around the axis of the suction flow passage, and this blow-out flow is then deflected back toward the suction target by a blow-out flow deflection guide, thereby realizing an air curtain that surrounds the suction target.

[0017] Furthermore, the suction device according to the second aspect is provided with an outlet flow swirl guide that swirls the outlet flow generated by the fan array consisting of multiple outlet fans, eliminating the need to arrange the rotation axes of the multiple outlet fans in a twisted manner relative to the axis of the suction flow passage, making it easy to manufacture.Furthermore, by making the outlet flow swirl guide a hood whose mounting angle can be adjusted independently for each outlet fan, it is possible to form an air curtain that is suited to the installation environment of the suction device, such as the distance from the suction target and the distance from the wall. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a longitudinal sectional view conceptually showing a first embodiment of a suction device according to the present invention. [Figure 2] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 3] FIG. 2 is a perspective view showing the appearance of the suction device of FIG. [Figure 4] FIG. 2 is an exploded perspective view showing the suction device of FIG. 1. [Figure 5] FIG. 10 is a vertical cross-sectional view conceptually showing a modified example of the first embodiment. [Figure 6]FIG. 2 is a longitudinal sectional view conceptually showing a second embodiment of a suction device according to the present invention. [Figure 7] FIG. 7 is a plan view of the device of FIG. 6. [Figure 8] FIG. 7 is a perspective view showing the appearance of the suction device of FIG. 6. [Figure 9] FIG. 1 is a perspective view showing a conventional suction device. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] (First embodiment) FIG. 1 is a vertical cross-sectional view conceptually showing the first embodiment, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, FIG. 3 is an external perspective view, and FIG. 4 is an exploded perspective view. As shown in FIG. 1, the suction device 1 of the first embodiment includes a suction flow passage 10, a suction fan 20, an outlet flow generating chamber 30, a plurality of outlet fans 40, an outlet flow deflection guide 50, and a rotation control unit 60.

[0021] The suction flow passage 10 has a substantially circular suction port 12 at the end facing the suction target 90, and is a passage through which the suction flow flows. In this embodiment, the suction flow passage 10 is formed inside a cylindrical suction duct 11.

[0022] The suction fan 20 is a fan that generates a suction flow, and in this embodiment is made up of a propeller fan 20a and a motor 20b that rotates it, and is disposed within the suction flow passage 10 so that its rotating shaft 20c is coaxial with the axis 10c of the suction flow passage 10. However, in the present invention, the suction fan 20 is not limited to this, and may be, for example, a centrifugal fan such as a sirocco fan, and the rotating shaft 20c does not have to be coaxial with the axis 10c of the suction flow passage 10.

[0023] The blown flow generating chamber 30 is formed in a substantially circular disk shape coaxially surrounding the suction flow passage 10, and is a space into which the blown flow is introduced from an inlet 31 on the opposite side to the suction target 90 and spreads in a circular disk shape. In this embodiment, the suction duct 11 is formed by an annular support disk 32 that extends outward from the outer periphery of the suction duct 11 along a plane perpendicular to the suction duct 11, and an annular guide disk 33 that is provided parallel to the support disk 32 on the opposite side of the suction target 90. The guide disk 33 is fixed to the support disk 32 via support walls 34 that are provided intermittently on the outer periphery of the support disk 32 (see FIGS. 3 and 4). The inlet 31 is formed in an annular shape between the inner periphery of the guide disk 33 and the outer periphery of the suction duct 11. The perspective view of Fig. 3 shows the suction device 1 in an assembled state, with the outer periphery of the top surface of the device covered by a guide disk 33 and an outlet flow deflection guide 50, which will be described later. The exploded perspective view of Fig. 4 shows a state in which the guide disk 33 and the outlet flow deflection guide 50 in Fig. 3 have been shifted upward, revealing the support disk 32 and the support walls 34 erected intermittently on its outer periphery.

[0024] As shown in Figure 2, the multiple blow-out fans 40 are provided at respective locations on the outer periphery of the blow-out flow generating chamber 30, and are fans that blow out the blow-out flow from the blow-out flow generating chamber 30 in an outward direction revolving around the axis 10c of the suction flow passage 10 (see Figure 1). In this embodiment, the multiple blowout fans 40 are each an axial fan made up of a propeller fan 40a and a motor 40b that rotates it. The multiple blowout fans 40 are provided between the support walls 34 in the blowout flow generating chamber 30, and are arranged so that the direction of their rotation axes 40c is rotated from a radial direction. As a result, the blowout flow passes from the inside of the blowout flow generating chamber 30 between the support walls 34 and is blown out in a direction rotated from a radial direction. When the suction fan 20 is provided coaxially within the suction flow passage 10 as in this embodiment, the "swirling direction" may be the same as or different from the rotation direction of the suction fan 20. However, if the "swirling direction" is the same as the rotation direction of the suction fan 20, the swirling direction of the blown-out flow (described later) and the direction in which the rotation of the suction fan 20 tries to swirl the suction flow are the same, which is preferable in that a tornado flow is more likely to occur. In this embodiment, each support wall 34 has a straight portion 34a that directs the blown flow obliquely outward, and an arc-shaped portion 34b that prevents the blown flow from returning to the inside of the blown flow generating chamber 30. However, the support wall 34 may have any shape as long as it can support the guide disk 33, and may be, for example, a pillar-like shape. The outlet flow generating chamber 30 has a planar space, so that the axial directions of the plurality of outlet fans 40 can be easily arranged in a swirling direction, and a swirling outlet flow can be easily generated.

[0025] As shown in FIG. 1, the blown air deflection guide 50 is provided on the outer periphery of the blown air generation chamber 30, and is a guide that deflects the blown air blown out in a plane by the multiple blown air fans 40 toward the suction target 90. In this embodiment, the blow-out flow deflection guide 50 is formed in an approximately circular ring shape when viewed from above, so as to continue from the outer periphery of the guide disk 33 of the blow-out flow generating chamber 30, and its vertical cross-sectional shape is a thin plate that curves from horizontal to downward from the inside to the outside. This blown-out flow deflection guide 50 deflects the blown-out flow from the plurality of blow-out fans 40 toward the suction target 90 while maintaining rotation around the axis 10c of the suction flow passage 10, forming a swirling, approximately cylindrical air curtain AC.

[0026] The rotation control unit 60 is a unit that individually controls the rotation speeds of the suction fan 20 and each of the blow-out fans 40, and any known means can be used. For example, if AC motors are used as the motors 20b, 40b that drive the fans, the rotation control unit 60 can be configured to control the drive frequency of the motors 20b, 40b using an inverter circuit. If DC motors are used as the motors 20b, 40b that drive the fans, the rotation control unit 60 can alternatively control the drive voltage level or PWM control of the motors 20b, 40b. By adjusting the output balance between the suction fan 20 and the blow-out fan 40 using the rotation control unit 60, it is possible to optimally set the flow rates of the suction flow and the blow-out flow, thereby enabling optimal suction tailored to the usage environment, such as the distance to the suction target 90. The rotation control unit 60 may have a function to detect an abnormality by known means when an abnormality occurs in one of the fans 20, 40, and to display a warning or perform control such as an emergency stop of the suction device 1.

[0027] Next, the operation of the suction device 1 of the first embodiment thus formed will be described with reference to Figures 1 and 2. In Figures 1 and 2, arrows (except for the arrows of the lead lines and the arrows indicating the viewing direction of the AA cross section) indicate the flow of air. When the suction fan 20 and the plurality of blowing fans 40 are rotationally driven, the plurality of blowing fans 40 introduce air from the inlet 31 into the blowing flow generation chamber 30. Because the side of the blowing flow generation chamber 30 facing the suction target 90 is closed by the support disk 32, the introduced air is spread into a disk shape within the blowing flow generation chamber 30 and is blown outward by the plurality of blowing fans 40 arranged on the outer periphery, rotating around the axis 10c of the suction flow passage 10 (see FIG. 2 ). The air is deflected by the blowing flow deflection guide 50 toward the suction target 90 while maintaining its rotation, and is blown out from the annular blowing port 51 between the blowing flow deflection guide 50 and the outer periphery of the support disk 32, forming a swirling, approximately cylindrical air curtain AC.

[0028] Meanwhile, the rotation of suction fan 20 generates a suction flow, and the air inside air curtain AC is sucked through suction flow passage 10 formed inside suction duct 11. As a result, the blown air that forms air curtain AC changes direction toward suction port 12 of suction flow passage 10 at a destination determined by its wind speed, or at a physical floor or flat surface, and then continues swirling and ascends toward suction port 12 of suction flow passage 10. At this time, by changing direction, the blown air reduces the swirling radius while maintaining its rotational kinetic energy, so the swirl speed increases and a tornado-like vortex is formed that reaches the suction target 90. This tornado-like vortex can efficiently suck in suction target 90 (for example, steam or smoke generated from a cooking range counter).

[0029] The sucked suction target 90 passes through a suction flow passage 10 formed inside a suction duct 11 as a suction flow and is exhausted, as shown in FIG.

[0030] According to the suction device 1 of this embodiment, a plurality of blow-out fans 40 form an outward blow-out flow that swirls around the axis 10c of the suction flow passage 10, and by changing the direction of this blow-out flow toward the object to be sucked 90 using the blow-out flow deflection guide 50, a large air curtain AC with sufficient blow-out speed and swirling speed can be formed, and the object to be sucked 90 can be surrounded and efficiently sucked in by the tornado flow. This configuration allows for easy manufacturing, stable formation of an air curtain AC that encloses a wide area, efficient suction of the enclosed area with a tornado flow, and smooth wind flow, thereby realizing a suction device 1 that is also quiet.

[0031] In addition, in this embodiment, the rotation control unit 60 controls the rotation speeds of the suction fan 20 and the blow-out fan 40 individually, thereby making it possible to optimally set the flow rates of the suction flow and the blow-out flow, thereby achieving optimal suction suited to the usage environment, such as the distance to the suction target 90. Furthermore, even if the installation location of the suction device 1 is close to a wall or the like, it is possible to offset the effect of the wall or the like on the air curtain AC by individually setting the flow rates of the multiple blow-out fans 40.

[0032] (Variation) FIG. 5 is a vertical cross-sectional view showing a modified example of the first embodiment. The suction device 1A of this modified example comprises an outer guide 71 extending the tip of the blown-out flow deflection guide 50, and an inner guide 72 provided along the outer periphery of the support disc 32 of the blown-out flow generating chamber 30, and further includes a blown-out flow straightening guide 70 for straightening the blown-out flow. The outer guide 71 and the inner guide 72 are each substantially cylindrical, skirt-shaped, or inverted skirt-shaped, and the cross-sectional shape and angle can be adjusted as appropriate. The outer guide 71 may be formed integrally with the outlet flow deflection guide 50, and the inner guide 72 may be formed integrally with the support disk 32. The connection between the support disk 32 and the inner guide 72 may be formed curved to avoid an angular shape. The rest of the configuration is the same as that of the suction device 1 of the first embodiment, and the operation is also the same.

[0033] In this modified example, the blown-out flow straightening guide 70 can stabilize the flow of the blown-out flow, stabilizing the air curtain AC formed by the blown-out flow and further stabilizing the tornado flow of the suction flow that is generated by the turning back. However, in the present invention, the blow-out flow straightening guide 70 is not essential, and the blow-out flow straightening guide 70 can be omitted when the distance between the suction device 1A and the suction target 90 is short or when it is necessary to secure space between the suction device 1A and the suction target 90.

[0034] (Second embodiment) FIG. 6 is a conceptual diagram of a second embodiment of the suction device according to the present invention, FIG. 7 is a plan view thereof, and FIG. 8 is a perspective view thereof. As shown in FIG. 6, the suction device 101 of the second embodiment includes a suction flow passage 110, a suction fan 120, a plurality of blow-out fans 130, a blow-out flow swirl guide 140, a support disk 150, and a rotation control unit 160.

[0035] The suction flow path 110 has a substantially circular suction port 112 at the end facing the suction target 90, and is a path through which the suction flow flows. In this embodiment, the suction flow path 110 is formed inside a cylindrical suction duct 111.

[0036] The suction fan 120 is a fan that generates a suction flow, and in this embodiment is made up of a propeller fan 120a and a motor 120b that rotates it, and is disposed within the suction flow passage 110 so that its rotation shaft 120c is coaxial with the axis 110c of the suction flow passage 110. However, in the present invention, the suction fan 120 is not limited to this, and may be, for example, a centrifugal fan such as a sirocco fan, and the rotation shaft 120c does not have to be coaxial with the axis 110c of the suction flow passage 110.

[0037] The multiple blow-out fans 130 are axial fans that are arranged approximately on the circumference surrounding the suction flow passage 110 in a plane perpendicular to the axis 110c of the suction flow passage 110, with their respective rotation axes 130c parallel to the axis 110c of the suction flow passage 110, to generate blow-out flows. In other words, the multiple blow-out fans 130 form a fan array. In this embodiment, each blow-out fan 130 is an axial fan that is composed of a propeller fan 130a and a motor 130b that rotates it.

[0038] The outlet flow swirl guide 140 is a guide that swirls the outlet flow from each outlet fan around the axis 110c of the suction flow passage 110. In this embodiment, the outlet flow swirl guide 140 is formed as an independent hood 141 for each outlet fan 130, and the outlet axis of the hood 141 is inclined toward the suction target 90 in a direction that swirls around the axis 110c of the suction flow passage 110 (see FIGS. 7 and 8), thereby swirling the outlet flow. When the suction fan 120 is provided coaxially within the suction flow passage 110 as in this embodiment, the "swirling direction" may be the same as or different from the rotation direction of the suction fan 120. However, if the "swirling direction" is the same as the rotation direction of the suction fan 120, the swirling direction of the blown-out flow (described later) and the direction in which the suction fan 120 tries to swirl the suction flow are the same, which is preferable in that a tornado flow is more likely to occur.

[0039] As shown in FIG. 8, each hood 141 has an air outlet 141a formed as a long hole in the direction of the rotation axis of the suction fan 120, so that when the airflows from each hood 141 are combined, a roughly cylindrical air curtain AC can be formed without any gaps. The mounting angle of each hood 141 can be adjusted independently, and the direction of the blowing axis of each hood 141 can be adjusted independently. However, in the present invention, the outlet flow swirl guide 140 is not limited to an independent hood 141 for each of the above-mentioned outlet fans 130, but may be anything that can swirl the outlet flow from the outlet fans 130, for example, a single hood that covers all of the outlet fans 130 arranged circumferentially and has multiple swirl blades fixed inside.

[0040] The support disk 150 is a base plate to which the suction flow passage 110, the plurality of blow-out fans 130, and the blow-out flow swirl guide 140 are fixed. In this embodiment, the support disk 150 is an annular disk that extends outward from the outer periphery of the suction duct 111 that forms the suction flow passage 110 along a plane perpendicular to the axis of the suction duct 111, and has through holes at equal intervals circumferentially on a circumference of a predetermined radius from the center, in which a blow-out fan 130 is arranged and a hood 141 serving as a blow-out flow swirl guide 140 is attached. In the present invention, the support disk 150 is not essential, and the suction flow passage 110, the plurality of blow-out fans 130, and the blow-out flow swirl guide 140 may be fixed by some other mechanism.

[0041] The rotation control unit 160 is a unit that individually controls the rotation speeds of the suction fan 120 and each of the blow-out fans 130, and can use any known means. Since it is similar to the rotation control unit 60 in the first embodiment, detailed description thereof will be omitted.

[0042] Next, the operation of the suction device 101 of the second embodiment thus formed will be described with reference to Figures 6 and 7. In Figures 6 and 7, arrows (except for the arrows of the lead lines) indicate the flow of air. When the suction fan 120 and the multiple blow-out fans 130 are driven to rotate, the multiple blow-out fans 130 blow out air parallel to the direction of the suction target 90, and each hood 141 (blow-out flow swirl guide 140) causes the air to swirl around the rotation axis 120c of the suction fan 120 (see Figure 7), and all the swirling blow-out flows are combined to form a swirling, approximately cylindrical air curtain AC.

[0043] Meanwhile, the rotation of suction fan 120 generates a suction flow, and the air inside air curtain AC is sucked through suction flow passage 110 formed inside suction duct 111. As a result, the blown air that has formed air curtain AC changes direction toward suction port 112 of suction flow passage 110 at a destination determined by its wind speed, or at a physical floor or flat surface, and continues to swirl as it rises toward suction port 112 of suction flow passage 110. At this time, the blown air turns back, reducing the swirling radius while maintaining its rotational kinetic energy, so that the swirl speed increases and a tornado-like vortex is formed that reaches the suction target 90. This tornado-like vortex can efficiently suck in suction target 90.

[0044] The sucked suction target 90 is exhausted as a suction flow through a suction flow passage 110 formed inside a suction duct 111, as shown in FIG.

[0045] According to suction device 101 of this embodiment, outlet flow swirl guide 140 is provided to swirl the outlet flow generated by the fan array consisting of multiple outlet fans 130, eliminating the need to twist rotation shafts 130c of multiple outlet fans 130 relative to rotation shaft 120c of suction fan 120, making manufacturing easier. Furthermore, by using outlet flow swirl guide 140 as hood 141 whose mounting angle can be adjusted independently for each outlet fan 130, it is possible to form an air curtain AC that is suited to the installation environment of suction device 101, such as the distance from suction target 90 and the distance from the wall.

[0046] Furthermore, in this embodiment, as in the first embodiment, the rotation control unit 160 controls the rotation speeds of the suction fan 120 and the blow-out fan 130 individually, thereby making it possible to optimally set the flow rates of the suction flow and the blow-out flow, thereby achieving optimal suction suited to the usage environment, such as the distance to the suction target 90. Furthermore, even if the installation location of the suction device 101 is close to a wall or the like, it is possible to offset the effect of the wall or the like on the air curtain AC by individually setting the flow rates of the multiple blow-out fans 130.

[0047] The present invention is not limited to the above-described embodiments. Those skilled in the art can make various additions and modifications within the scope of the present invention. For example, in the above-described embodiments, as shown in Figures 2 and 6, both the outlet flow and the suction flow rotate clockwise when viewed from above, but the present invention is not limited to this, and they may also rotate counterclockwise. [Explanation of symbols]

[0048] 1,1A suction device 10 Suction flow path 10c axis 11 Suction duct 12 Suction port 20 Suction fan 20a Propeller Fan 20b motor 20c Rotational Axis 30 Outlet flow generation chamber 31 Introduction 32 Support disc 33 Guide disc 34 Supporting wall 34a Straight section 34b Arc-shaped part 40 Blowing fan 40a Propeller Fan 40b motor 40c pivot point 50 Outlet flow deflection guide 60 Rotation control section 70 Outlet flow straightening guide 71 Outer guide 72 Inner guide 90 Suction Target 101 Suction device 110 Suction flow path 110c axis 111 Suction duct 112 Suction port 120 Suction fan 120a Propeller Fan 120b motor 120c pivot point 130 Blowing fan 130c pivot 140 Outlet flow swirl guide 141 Food 141a Air outlet 150 Support disc 160 Rotation control section 220 Suction fan (conventional suction device) 230 Blowing fan (conventional suction device) AC Air Curtain AC

Claims

1. A suction device for performing local exhaust, a suction flow passage having a substantially circular suction port at an end portion facing the suction target and through which a suction flow flows; a suction fan that generates the suction flow in the suction flow passage; an outlet flow generating chamber formed in a substantially circular plate shape coaxially surrounding the suction flow passage, into which an outlet flow is introduced from an inlet on the opposite side to the suction target and spreads in a circular plate shape; a plurality of blowout fans provided at respective locations on the outer periphery of the blowout flow generating chamber, the blowout fans blowing the blowout flow from the blowout flow generating chamber in an outward direction revolving around the axis of the suction flow passage; a blowout flow deflection guide provided on the outer periphery of the blowout flow generating chamber and deflecting the blowout flows blown out by the plurality of blowout fans toward the suction target.

2. 2. The suction device according to claim 1, further comprising an outlet flow straightening guide for straightening the outlet flow, the outlet flow straightening guide comprising an outer guide provided to extend the tip of the outlet flow deflection guide and an inner guide provided along the outer periphery of the outlet flow generating chamber.

3. A suction device for performing local exhaust, a suction flow passage having a substantially circular suction port at an end portion facing the suction target and through which a suction flow flows; a suction fan that generates the suction flow in the suction flow passage; a blowout fan consisting of a plurality of axial flow fans arranged on a substantial circumference surrounding the suction flow passage in a plane perpendicular to the axis of the suction flow passage, with the rotation axes being parallel to the axis of the suction flow passage, and generating a blowout flow; a blowout flow swirl guide for swirling the blowout flow from each of the blowout fans around the axis of the suction flow passage.

4. 4. The suction device according to claim 3, wherein the outlet flow swirl guide is formed as an independent hood for each of the outlet fans, and the mounting angle can be adjusted independently.

5. 5. The suction device according to claim 4, wherein each of the hoods has an air outlet formed as a long hole that is long in the axial direction of the suction flow passage, so that when the air flows from each of the hoods are combined, a substantially cylindrical air curtain can be formed without any gaps.

6. 6. The suction device according to claim 1, further comprising a rotation control unit that controls the rotation speeds of the suction fan and each of the blowing fans individually.

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