Cyclone separation device

Abstract

To provide a cyclone separation device that reduces pressure loss in generating a swirl airflow.SOLUTION: A cyclone separation device (ventilation port hood) comprises a plurality of fixed blades 8 for generating a swirl airflow in a housing using air flowing in from an inflow port. The plurality of fixed blades 8 respectively has: a straight shape part 81 of a prescribed thickness, which includes an end 83 of a downstream side and an end 85 on an upstream side, and which is arranged by being inclined to a prescribed angle (angle D1) relative to a straight line L1 connecting a central axis 6 and a midpoint of the end 83 of the downstream side, in a cross-sectional shape of the fixed blade 8 according to a plane view with the central axis 6 of a swirl chamber as the normal line; and a curved shape part 82 which is provided by extending to the upstream side from the straight shape part 81, and in which the end 85 of the upstream side is curved to an external surface S1 side of the fixed blade 8 beyond the straight shape part 81. The plurality of fixed blades 8 are arranged at a prescribed interval along the circumference of a cylinder (cylinder surface A1) with the central axis 6 of the swirl chamber as its center.SELECTED DRAWING: Figure 5

Description

Technical Field

[0006] , , , , ,

[0001] The present invention relates to a cyclone separator that separates foreign substances contained in the air using centrifugal force.

Background Art

[0002] Conventionally, this type of cyclone separator has been used by being attached to the air supply port portion of the outer wall of a house in order to separate insects or dust (hereinafter referred to as foreign substances) that are sucked in together with the outside air when taking in the outside air into the room.

[0003] Conventionally, for example, a cyclone separator of Patent Document 1 is known. FIG. 8 is an external perspective view of a conventional cyclone separator.

[0004] As shown in FIG. 8, a circular inlet 102 in which a plurality of fixed blades 101 are arranged radially at equal intervals with gaps on one end face in the axial direction, and a circular outlet (on the back side of the figure coaxial with the inlet 102) on the other end face. The space between the inlet 102 and the outlet is a cylindrical swirling chamber 103. The air that enters from the inlet 102 becomes a swirling air current by the fixed blades 101, and then the air current flows out from the outlet. Below the swirling chamber 103, there is a separation chamber 104 for accommodating the foreign substances separated from the air by the swirling air current.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In conventional cyclone separation devices, the air drawn in from the inlet 102 is swirled within the device by the fixed vanes 101. Due to the shape of the fixed vanes 101, airflow turbulence is likely to occur, potentially leading to increased pressure loss. From this perspective, there was room for further improvement to the fixed vanes 101.

[0007] Therefore, the present invention aims to provide a cyclone separation device that can reduce pressure loss when generating a swirling airflow. [Means for solving the problem]

[0008] To achieve this objective, the cyclone separation device according to the present invention comprises: an inlet for introducing air into the housing; a plurality of fixed vanes that generate a swirling airflow inside the housing with the air flowing in from the inlet; an outlet provided on the back of the housing for releasing the air flowing in from the inlet to the outside of the housing; a space dividing plate that divides the inside of the housing into a swirling chamber located on the inner circumference side including the center of the housing and communicating with the inlet, and a separation chamber located on the outer circumference side of the swirling chamber; a through hole provided in the space dividing plate that connects the separation chamber and the swirling chamber; and an outlet provided at a position below the direction of gravity in the separation chamber when the central axis of the housing is positioned horizontally, which connects the separation chamber to the outside of the housing. In the cyclone separation device, each of the multiple fixed vanes has a downstream end and an upstream end. The cross-sectional shape of the fixed vane, in a plane normalized to the central axis of the swirling chamber, has a linear section of a predetermined thickness that is inclined at a predetermined angle with respect to a line connecting the central axis and the midpoint of the downstream end, and a curved section that extends upstream from the linear section, with the upstream end curving toward the outer surface of the fixed vane more than the linear section. The multiple fixed vanes are arranged at predetermined intervals along the circumference of a cylinder centered on the central axis of the swirling chamber on the rear side of the swirling chamber, thereby achieving the intended purpose. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a cyclone separation device that can reduce pressure loss when generating a swirling airflow. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view of the ventilation hood according to Embodiment 1 of the present invention, seen from the diagonally downward front side. [Figure 2] Figure 2 is a side cross-sectional view of the ventilation hood according to Embodiment 1. [Figure 3] Figure 3 is a detailed view of the rectangular separator that constitutes the ventilation hood according to Embodiment 1. [Figure 4] Figure 4 is a perspective view of the fixed vanes constituting the ventilation hood according to Embodiment 1. [Figure 5] Figure 5 is a front cross-sectional view of the fixed vanes constituting the ventilation hood according to Embodiment 1. [Figure 6] Figure 6(a) is a front cross-sectional view showing the airflow around the fixed vanes constituting the ventilation hood according to Embodiment 1, and Figure 6(b) is a front cross-sectional view showing the airflow around the fixed vanes constituting the ventilation hood according to a comparative example. [Figure 7] Figure 7(a) is a front cross-sectional view of the fixed vanes constituting the ventilation hood according to Embodiment 2 of the present invention, and Figure 7(b) is a front cross-sectional view showing the airflow around the fixed vanes constituting the ventilation hood. [Figure 8] Figure 8 is a perspective view of a conventional cyclone separation device. [Modes for carrying out the invention]

[0011] The cyclone separation device according to the present invention comprises an inlet for introducing air into the housing, a plurality of fixed vanes that generate a swirling airflow inside the housing with the air flowing in from the inlet, an outlet provided on the back of the housing for releasing the air that has flowed in from the inlet to the outside of the housing, a space dividing plate that divides the inside of the housing into a swirling chamber located on the inner circumference side including the center of the housing and communicating with the inlet, and a separation chamber located on the outer circumference side of the swirling chamber, a through hole provided in the space dividing plate that connects the separation chamber and the swirling chamber, and an outlet provided at a position below the direction of gravity in the separation chamber when the central axis of the housing is positioned horizontally, which connects the separation chamber to the outside of the housing. In the cyclone separation device, each of the multiple fixed vanes has a downstream end and an upstream end. The cross-sectional shape of the fixed vane, in a plane normalized to the central axis of the swirling chamber, has a linear portion of a predetermined thickness that is inclined at a predetermined angle with respect to a line connecting the central axis and the midpoint of the downstream end, and a curved portion that extends upstream from the linear portion, with the upstream end curving toward the outer surface of the fixed vane more than the linear portion. The multiple fixed vanes are arranged at predetermined intervals along the circumference of a cylinder centered on the central axis of the swirling chamber on the rear side of the swirling chamber.

[0012] With this configuration, when air flowing into the housing from outside through the inlet is deflected by the fixed vanes, the air is gradually deflected along the curved portion of the fixed vanes to follow the straight portion, thereby suppressing airflow separation on the inner surface of the fixed vanes. This reduces pressure loss caused by airflow separation. In other words, it is possible to create a cyclone separation device that can reduce pressure loss when generating a swirling airflow.

[0013] In the cyclone separator according to the present invention, the curved portion has a predetermined curvature, and may be configured to be curved such that a tangent line on the inner surface side of the fixed blade at the upstream end portion is parallel to a straight line connecting the central axis and the midpoint of the upstream end portion. Thereby, in a plane having the central axis of the swirling chamber as a normal line, the air sucked from the space outside the housing toward the central axis flows along the curved portion at the upstream end portion of the fixed blade, so that the separation of the air flow on the inner surface side surface of the fixed blade is suppressed. Therefore, the pressure loss can be surely reduced.

[0014] In the cyclone separator according to the present invention, in the cross-sectional shape of the fixed blade, the curved portion may be configured such that the length between the upstream side and the downstream side is shorter than that of the straight portion. Thereby, the longer the straight portion is, the easier it is for the air to be deflected by the fixed blade, and the easier it is to generate a more swirling air flow. On the other hand, the shorter the length between the upstream end portion and the downstream end portion of the fixed blade is, the smaller the friction with the air is. Therefore, when generating a swirling air flow for separating foreign matters, the pressure loss can be more surely reduced.

[0015] In the cyclone separator according to the present invention, the predetermined thickness of the straight portion may be configured to be thinner from the upstream side to the downstream side of the straight portion. Thereby, at the downstream end portion of the fixed blade, the space between the air flow flowing through the downstream end portion on the outer surface side of the fixed blade and the air flow flowing through the downstream end portion on the inner surface side of the fixed blade becomes smaller, and the turbulence caused by the air flows intersecting at the downstream end portion of the fixed blade is suppressed. Therefore, the pressure loss when generating a swirling air flow can be further reduced.

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0017] (Embodiment 1) In the present embodiment, the following description will be made based on an example in which the cyclone separator is applied to a ventilation port hood.

[0018] FIG. 1 is a perspective view seen from the obliquely lower front side of the ventilation port hood 1 according to Embodiment 1 of the present invention.

[0019] The ventilation hood 1 shown in Fig. 1 is attached to an air supply port provided on the outer wall of a house to take in outdoor air into the house.

[0020] An apparatus (not shown) for taking in outdoor air into the house includes a blower (not shown) and a ventilation duct (not shown) installed in the house, and connects the blower and the ventilation hood 1. Thereby, the air passing through the ventilation hood 1 can be introduced into the room. The ventilation hood 1 separates foreign substances contained in the air by using the centrifugal force of a swirling air flow generated around the central axis 6 when taking in outside air into the house.

[0021] The ventilation hood 1 is connected to the ventilation duct using the outflow pipe 2 and is installed protruding from the outer wall of the house.

[0022] Next, the external configuration of the ventilation hood 1 will be described.

[0023] The ventilation hood 1 includes a housing 5, fixed blades 8, and a discharge part 11.

[0024] The housing 5 has a hexahedron shape formed by a front cover 3 and a base plate 4 on the back side.

[0025] The cover 3 is a rectangular box that closes the front side of the housing 5, and a part of the four side surfaces on the back side is open as an inlet 7. Note that the front side surface in Fig. 1, that is, the front shape of the ventilation hood 1 may be a dome shape with a protruding central part even if it is a flat shape.

[0026] The base plate 4 has a circular opening in the central part, and the outflow pipe 2 is connected to the opening. The air inside the cover 3 flows out from the outlet 9 at one end of the outflow pipe 2. The base plate 4 is adjacent to the side surface of the cover 3, and the housing 5 forms the outer contour of the ventilation hood 1.

[0027] The fixed vanes 8 are components that generate a swirling airflow within the housing 5 using air flowing in from the inlet 7. Multiple fixed vanes 8 are arranged downstream of the inlet 7 at equal intervals in a rotationally symmetrical manner with respect to the central axis 6, serving as means for generating a swirling airflow that causes the incoming air to swirl. Further details will be described later.

[0028] Furthermore, to prevent large insects or birds from entering the device, nets may be provided around the outer periphery of the inlet 7 and the fixed blades 8.

[0029] The discharge section 11 is provided at the lower part of the cover 3, protruding from the side, when the central axis 6 is positioned substantially horizontally. More specifically, the discharge section 11 has a discharge-facing surface 10 and a discharge port 12.

[0030] The discharge-promoting surface 10 consists of two symmetrically arranged surfaces that are connected to two other surfaces, forming a permanently open discharge port 12 at its lowest point. The discharge-promoting surface 10 is inclined so that its cross-sectional area decreases towards the bottom, and has a discharge port 12 at its tip that connects the inside and outside of the ventilation hood 1.

[0031] The exhaust port 12 is an opening provided at the lower tip of the exhaust section 11 to connect the inside and outside of the ventilation hood 1, and is a long rectangle in the direction of the central axis 6. The elongated shape makes it difficult for large insects or birds to enter, and provides a larger surface area for easily discharging separated foreign matter. Furthermore, the exhaust port 12 is made long in the direction of the central axis 6 in order to enhance the discharge effect by natural airflow, which will be described later.

[0032] The symmetrical structure of the exhaust-promoting surface 10 is intended to achieve the same exhaust-promoting effect regardless of whether the natural wind blows from the left or the right. While the exhaust-promoting surface 10 needs to have inclinations on both the left and right sides, it does not need to be strictly symmetrical; slight differences in angle are acceptable. In particular, in this embodiment, the surface is designed to gradually steepen like an inverted Mount Fuji, allowing the natural wind impacting the exhaust-promoting surface 10 to smoothly change direction.

[0033] Next, the internal configuration of this device will be described using Figures 2 and 3. Figure 2 is a side cross-sectional view of the ventilation hood 1 according to Embodiment 1. Figure 3 is a detailed view of the rectangular separator 19 that constitutes the ventilation hood 1 according to Embodiment 1. Note that Figure 3 shows the positional relationship between the cover 3 and the rectangular separator 19.

[0034] With the discharge section 11 positioned at the bottom of the cover 3, as shown in Figure 2, the internal space surrounded by the cover 3 and the base plate 4 is equipped with a fixed vane 8, an inner cylindrical tube 17, a space dividing plate 13, and a rectangular separator 19.

[0035] The base plate 4 is connected to the inner tube 17 and the fixed vanes 8. With the inner tube 17 facing inward, the inner tube 17 and the fixed vanes 8 are arranged concentrically with respect to the central axis 6.

[0036] The inner tube 17 is a tubular body that communicates with the outlet pipe 2. The inner tube 17 is located on the opposite side of the base plate 4 so as to communicate with the outlet 9. Furthermore, the inner tube end face 18 of the inner tube 17 is positioned on the front side of the cover 3 relative to the position of the fixed vanes 8 inside the cover 3. In other words, it is positioned on the back side when viewed from the fixed vanes 8 in the direction of the central axis 6. In this embodiment, the inner diameter of the inner tube 17 is different from the inner diameter of the outlet pipe 2 in the base plate 4 portion, with the inner diameter of the inner tube 17 being smaller than the inner diameter of the outlet pipe 2, but they may be the same size. In the base plate 4 portion, a rapid expansion occurs towards the outlet pipe 2 side, so if turbulence in the airflow is expected, the shape may be made to gradually expand.

[0037] As shown in Figure 3, the rectangular separator 19 is a plate with an opening 20 in the center, positioned perpendicular to the central axis 6, and dividing the internal space into two. As shown in Figure 2, the rectangular separator 19 has fixed vanes 8 connected to one side and a space-dividing plate 13 connected to the other side. In other words, the fixed vanes 8, the rectangular separator 19, and the space-dividing plate 13 are arranged in that order within the internal space enclosed by the cover 3 and the base plate 4. The inlets 7, which are provided on the four sides of the cover 3 opposite the fixed vanes 8, are positioned on the back side of the cover 3 with the rectangular separator 19 as the boundary, as shown in Figure 3. As a result, the fixed vanes 8 and the inlets 7 face each other.

[0038] The spatial division plate 13 is a cylindrical body whose axis is aligned with the central axis 6, dividing the inside of the cover 3 into an inner and outer section. More specifically, the spatial division plate 13 divides the inside of the housing 5 (cover 3) into a swivel chamber 14 located on the inner circumference side, which is in communication with the inlet 7 and includes the center of the housing 5 (cover 3), and a separation chamber 15 located on the outer circumference side of the swivel chamber 14. The cross-section of the swivel chamber 14 formed inside the spatial division plate 13 (in the plane direction perpendicular to the central axis 6) is such that the cross-sectional area widens towards the base plate 4 side within the cover 3, and it has a frustoconical shape with inclined sides. However, it may also be a cylindrical shape with a constant cross-sectional area.

[0039] As described above, the inside of the spatial division plate 13 is a rotating chamber 14 that includes the center of the cover 3, and the outer peripheral side of the spatial division plate 13, closer to the side of the cover 3 (the space enclosed by the spatial division plate 13 and the cover 3), is a separation chamber 15. The spatial division plate 13 is provided with a through hole 16, through which the rotating chamber 14 and the separation chamber 15 are connected.

[0040] The through-hole 16 is provided in the space-dividing plate 13 and is an opening that connects the separation chamber 15 and the swivel chamber 14. The through-hole 16 is located on the front side of the cover 3 and above the central axis 6 when the central axis 6 is positioned approximately horizontally.

[0041] Next, the fixed vanes 8 will be described in detail using Figures 4 and 5. Figure 4 is a perspective view of the fixed vanes 8 constituting the ventilation hood 1 according to Embodiment 1. Figure 5 is a front cross-sectional view of the fixed vanes 8 constituting the ventilation hood 1 according to Embodiment 1. Note that the front cross-sectional view in Figure 5 corresponds to the cross-sectional shape of the plane normalized to the central axis 6 of the housing 5 (swivel chamber 14).

[0042] Multiple fixed vanes 8 are provided downstream of the inlet 7 as means for generating a swirling flow that causes the incoming air to swirl. As shown in Figure 4, the multiple fixed vanes 8 are positioned vertically parallel to the central axis 6 from the front side of the base plate 4 and are inclined at a predetermined angle (angle D1) with respect to a radial line L1 passing through the central axis 6, and are arranged at equal intervals in a rotationally symmetrical manner with respect to the central axis 6. It can also be said that the multiple fixed vanes 8 are arranged at predetermined intervals along the circumference of a cylinder centered on the central axis 6 of the swirling chamber 14 on the rear side of the swirling chamber 14.

[0043] Each of the fixed blades 8 has an outer surface S1 facing outwards (opposite the central axis 6) and an inner surface S2 facing inwards (towards the central axis 6). The fixed blades 8 also include a straight-shaped portion 81 of a predetermined thickness and a curved-shaped portion 82 that extends from the upstream side of the straight-shaped portion 81 and curves toward the outer surface S1.

[0044] More specifically, each of the fixed blades 8, as shown in Figure 5, has a downstream end 83 and an upstream end 85, and is configured with a linear portion 81 of a predetermined thickness that is inclined at a predetermined angle with respect to a straight line L1 connecting the central axis 6 and the midpoint of the end 83, and a curved portion 82 that extends upstream from the linear portion 81 and whose end 85 is curved toward the outer surface S1 of the fixed blade 8 than the linear portion 81.

[0045] The linear section 81 is rectangular in shape, having a downstream end 83 and an upstream end 84. The linear section 81 has a predetermined thickness. The midpoint of the end 83 of the linear section 81 lies on the intersection of a cylindrical surface A1 centered on the central axis 6 and a radial line L1 passing through the central axis 6. The linear section 81 is positioned such that a line L3 passing through the midpoint of the end 83 and the midpoint of the end 84 is inclined at an angle D1 between it and the line L1.

[0046] The curved section 82 is an arc shape that connects the downstream end 84 and the upstream end 85 with a predetermined curvature. In other words, end 84 is both the upstream end of the straight section 81 and the downstream end of the curved section 82. The midpoint of end 85 of the curved section 82 lies on a cylindrical surface A2 that is larger than the cylindrical surface A1 centered on the central axis 6, and is positioned on the outer surface S1 side of the straight line L3. End 85 is also tangent to the cylindrical surface A2 and forms a line segment perpendicular to the straight line L2 that passes through end 85 and the central axis 6. The curves on the outer surface S1 side and the inner surface S2 side connecting end 84 and end 85 each have a constant curvature, and end 84 and end 85 intersect the outer surface S1 and inner surface S2 perpendicularly, respectively. In other words, the curved section 82 is smoothly connected to the straight section 81 at end 84, and the tangent line L4 on the inner surface S2 side at end 85 is parallel to the straight line L2.

[0047] Furthermore, the length of the curved portion 82 is configured to be shorter than that of the straight portion 81. In other words, the distance between the midpoint of end 85 and the midpoint of end 84 is smaller than the distance between the midpoint of end 84 and the midpoint of end 83.

[0048] Next, with reference to Figure 2, the airflow in the above configuration will be explained.

[0049] When the blower (not shown) is operated, outdoor air containing foreign matter flows into the ventilation hood 1 from the inlet 7. Passing through the fixed blades 8 creates a swirling airflow, and since the inner cylindrical tube 17 is positioned on the front side of the ventilation hood 1 relative to the inlet 7, it swirls within the swirling chamber 14 while moving towards the front side of the ventilation hood 1. Here, the foreign matter moves towards the space dividing plate 13 due to centrifugal force and moves into the separation chamber 15 as it passes near the through-hole 16. The air from which the foreign matter has been separated flows into the inner cylindrical tube 17 and flows out of the device through the outlet pipe 2 and outlet 9.

[0050] Foreign matter that has moved into the separation chamber 15 is temporarily stored in the separation chamber 15. Because the inside of the ventilation hood 1 is under negative pressure relative to the outside of the ventilation hood 1 due to the blower, air flows into the separation chamber 15 from the exhaust port 12. This incoming air passes through the through hole 16 and flows into the swirling chamber 14, where it merges with the swirling airflow in the swirling chamber 14.

[0051] Furthermore, when natural wind blows on the outdoor side of the discharge port 12, the static pressure on the outdoor side of the discharge port 12 decreases, and when it becomes lower than the static pressure on the separation chamber 15 side, the separated foreign matter is pulled out to the outside. As a result, the foreign matter is automatically discharged to the outside, so foreign matter does not continue to accumulate in the separation chamber 15, eliminating the need for maintenance to remove accumulated matter.

[0052] Next, the airflow passing through the fixed vanes 8 will be explained using Figure 6. Figure 6(a) is a front cross-sectional view showing the airflow around the fixed vanes 8 constituting the ventilation hood 1 according to Embodiment 1, and Figure 6(b) is a front cross-sectional view showing the airflow around the fixed vanes 8x constituting the ventilation hood according to a comparative example.

[0053] As shown in Figure 6(a), the airflow 30 flowing in from the inlet 7 flows radially toward the central axis 6. A portion of the airflow 31a flowing into the fixed vane 8 flows along the outer surface S1 of the fixed vane 8 and is deflected in a direction parallel to the straight line L3. On the other hand, another portion of the airflow 31b passes from the upstream end 85 of the fixed vane 8 to the inner surface S2. That is, the airflow 31b flows into the inner surface S2 along the tangent L4. At this time, the region between the airflow 31b and the inner surface S2 is under negative pressure relative to the surroundings, so the airflow 31b flows along the inner surface S2 and is deflected in a direction parallel to the straight line L3 on the inner surface S2 side. Then, downstream of the fixed vane 8, the airflow 31a and airflow 31b merge to form airflow 32, which flows into the swirling chamber 14, and the airflow 32, deflected by the multiple fixed vanes 8, creates a swirling airflow.

[0054] In contrast, in the case of a ventilation hood according to a comparative example, which has a fixed vane 8x that does not have a curved shape and is composed only of a straight shape, as shown in Figure 6(b), the airflow 40 flowing in from the inlet 7 flows radially toward the central axis 6, centered on the central axis 6. A portion of the airflow 40 flowing into the fixed vane 8x, 41a, flows along the outer surface S3 which is outside the fixed vane 8x and is deflected in a direction parallel to the straight line L3. On the other hand, another portion of the airflow 40, 41b, passes on the inner surface S4 side which is inside the upstream end 85x of the fixed vane 8x. In other words, the airflow 41b flows into the inner surface S2 side along the straight line L2. In this case, upstream of the inner surface S4, there is an angle between the tangent to the inner surface S4 (a straight line parallel to the straight line L3) and the inflow direction of the passing airflow 40 (a direction along the straight line L2). As a result, separation of the airflow 41b occurs on the inner surface S2 side of the fixed vane 8x, creating a negative pressure region SA1 between the airflow 41b and the inner surface S4. The greater the flow velocity of the airflow 40 (i.e., airflow 41b), the larger the negative pressure region SA1 becomes, which is a factor in pressure loss in the airflow 41b. Ultimately, the airflow 41b flows along the inner surface S2 and is deflected in a direction parallel to the straight line L3 on the inner surface S2 side. Then, the deflected airflow 41a and the deflected airflow 41b combine to form airflow 42, which flows as a swirling airflow.

[0055] As described above, in the ventilation hood 1 according to this embodiment, the fixed vane 8 is provided with a curved portion 82 on the upstream side, so that the airflow 31b flows in such a way that it suppresses the formation of a negative pressure region SA1 caused by the separation of airflow between the airflow 30 (i.e., airflow 31) and the inner surface S2 side of the fixed vane 8. In other words, the ventilation hood 1 can reduce pressure loss when generating a swirling airflow.

[0056] As described above, the ventilation hood 1 according to this embodiment 1 can be enjoyed with the following effects.

[0057] (1) The ventilation hood 1 comprises an inlet 7 for introducing air into a housing 5 consisting of a cover 3 and a base plate 4, a plurality of fixed vanes 8 that generate a swirling airflow inside the housing 5 with the air flowing in from the inlet 7, an outlet 9 for connecting to a ventilation duct provided on the base plate 4, a rectangular separator 19 and a space dividing plate 13 that divide the inside of the housing 5 into a swirling chamber 14 and a separation chamber 15, a through hole 16 provided in the space dividing plate 13, and an exhaust section 11 that is located below the direction of gravity in the separation chamber 15 when the central axis 6 of the housing 5 is positioned horizontally, and which connects the separation chamber 15 to the outside of the housing. Each of the multiple fixed blades 8 has a downstream end 83 and an upstream end 85. In the cross-sectional shape of the fixed blade 8 in a plane normalized to the central axis 6 of the swivel chamber 14, it has a linear portion 81 of a predetermined thickness that is inclined at a predetermined angle D1 with respect to a straight line L1 connecting the central axis 6 and the midpoint of the downstream end 83, and a curved portion 82 that extends upstream from the linear portion 81, with the upstream end 85 curving toward the outer surface S1 of the fixed blade 8 more than the linear portion 81. The multiple fixed blades 8 are arranged at predetermined intervals along a cylindrical surface A1 centered on the central axis 6 of the swivel chamber 14 on the rear side of the swivel chamber 14.

[0058] In other words, the ventilation hood 1 comprises an inlet 7 for introducing air into the housing 5, a plurality of fixed vanes 8 that generate a swirling airflow inside the housing 5 with the air flowing in from the inlet 7, an outlet 9 provided on the back of the housing 5 for releasing the air that has flowed in from the inlet 7 to the outside of the housing 5, a space dividing plate 13 that divides the inside of the housing 5 into a swirling chamber 14 located on the inner circumference side including the center of the housing 5 and communicating with the inlet 7, and a separation chamber 15 located on the outer circumference side of the swirling chamber 14, a through hole 16 provided in the space dividing plate 13 that connects the separation chamber 15 and the swirling chamber 14, and an outlet 12 provided at a position below the direction of gravity in the separation chamber 15 when the central axis 6 of the housing 5 is positioned horizontally, and which connects the separation chamber 15 to the outside of the housing 5. In the ventilation hood 1, each of the multiple fixed vanes 8 has a downstream end 83 and an upstream end 85. In the cross-sectional shape of the fixed vane 8 in a plane normalized to the central axis 6 of the swivel chamber 14, it has a linear portion 81 of a predetermined thickness that is inclined at a predetermined angle (angle D1) with respect to a straight line L1 connecting the central axis 6 and the midpoint of the downstream end 83, and a curved portion 82 that extends upstream from the linear portion 81, with the upstream end 85 curving toward the outer surface S1 of the fixed vane 8 more than the linear portion 81. The multiple fixed vanes 8 are arranged on the back side of the swivel chamber 14 at predetermined intervals (equal intervals) along the circumference of a cylinder (cylindrical surface A1) centered on the central axis 6 of the swivel chamber 14.

[0059] With this configuration, when the air (airflow 30) flowing into the housing 5 from outside the housing 5 through the inlet 7 is deflected by the fixed vane 8, the airflow (airflow 31b) on the inner surface S2 of the fixed vane 8 is gradually deflected along the curved portion 82 of the fixed vane 8 to follow the straight portion 81, thereby suppressing separation of the airflow (airflow 31b) on the inner surface S2 of the fixed vane 8. As a result, pressure loss caused by the separation of the airflow (airflow 31b) is reduced. In other words, a ventilation hood 1 can be made that reduces pressure loss when generating a swirling airflow.

[0060] (2) In the ventilation hood 1, the curved portion 82 has a predetermined curvature, and the tangent L4 on the inner surface S2 side of the fixed vane 8 at the upstream end 85 is curved so that it is parallel to the straight line L2 connecting the central axis 6 and the midpoint of the upstream end 85. As a result, in the plane normal to the central axis 6 of the swirling chamber 14, the air (airflow 30) drawn in from the space outside the housing 5 toward the central axis 6 flows along the curved portion 82 at the upstream end 85 of the fixed vane 8, thereby suppressing separation of the airflow (airflow 31b) on the inner surface S2 of the fixed vane 8, and thus the pressure loss can be reliably reduced.

[0061] (3) In the ventilation hood 1, the cross-sectional shape of the fixed vane 8 is configured such that the length between the upstream and downstream sides of the curved section 82 is shorter than that between the straight section 81. In other words, the distance between the midpoint of the upstream end 85 and the midpoint of the end 84 is smaller than the distance between the midpoint of the end 84 and the midpoint of the downstream end 83. As a result, the longer the straight section 81, the easier it is for the air to be deflected by the fixed vane 8, making it easier to create a more swirling airflow. On the other hand, the shorter the length between the upstream end 85 and the downstream end 83 of the fixed vane 8, the less friction there is with the air. Therefore, when generating a swirling airflow (airflow 32) to separate foreign matter, pressure loss can be reduced more reliably.

[0062] (Embodiment 2) Next, with reference to Figure 7, the fixed vanes 8a constituting the ventilation hood 1a according to Embodiment 2 of the present invention will be described. Figure 7(a) is a front cross-sectional view of the fixed vanes 8a constituting the ventilation hood 1a according to Embodiment 2 of the present invention, and Figure 7(b) is a front cross-sectional view showing the airflow around the fixed vanes 8a constituting the ventilation hood 1a.

[0063] The fixed vane 8a constituting the ventilation hood 1a in this second embodiment differs from that in embodiment 1 in that the thickness T1 of the downstream end 83a is thinner than the thickness T2 of the upstream end 84a of the linear portion 81a of the fixed vane 8a. The rest of the configuration of the ventilation hood 1a is the same as that of the ventilation hood 1 in embodiment 1. The following will mainly describe the differences from embodiment 1, and will omit further explanations of the contents already described in embodiment 1 as appropriate. Note that the straight lines L1 to L3 and the tangent line L4 in Figure 7 are set under the conditions defined in embodiment 1.

[0064] The fixed vane 8a constituting the ventilation hood 1a according to this second embodiment has, as shown in Figure 7(a), an outer surface S1a facing outward (opposite side of the central axis 6) and an inner surface S2a facing inward (towards the central axis 6). The fixed vane 8a also includes a straight-shaped portion 81a whose thickness is thinner on the downstream side than on the upstream side, and a curved-shaped portion 82a that extends from the upstream side of the straight-shaped portion 81a and curves toward the outer surface S1a side.

[0065] More specifically, the fixed vane 8a has a downstream end 83a and an upstream end 85a, and, like the fixed vane 8, it is configured with a linear portion 81a that is inclined at a predetermined angle (angle D1 in Figure 5) with respect to the straight line L1, and a curved portion 82a that extends upstream from the linear portion 81a, with the end 85a curving toward the outer surface S1a of the fixed vane 8a more than the linear portion 81a.

[0066] The linear portion 81a is rectangular in shape, having a thickness T1 at the downstream end 83a and a thickness T2 at the upstream end 84a. In other words, the linear portion 81a gradually thins from the upstream side (thickness T2) to the downstream side (thickness T1). More specifically, the linear portion 81a is formed so that its thickness decreases from the upstream side to the downstream side by machining the inner surface S2 side of the member compared to the linear portion 81 of the fixed blade 8.

[0067] The curved portion 82a is an arc shape that connects the downstream end 84a and the upstream end 85a with a predetermined curvature, and has the same shape as the curved portion 82 of the fixed vane 8.

[0068] Furthermore, the length of the curved portion 82a is also configured to be shorter than that of the straight portion 81a, similar to the fixed vane 8.

[0069] Next, as shown in Figure 7(b), in the ventilation hood 1a, the airflow 50 flowing in from the inlet 7 flows radially towards the central axis 6, similar to the airflow 30 in the ventilation hood 1. A portion of the airflow 50 flowing into the fixed vane 8a, 51a, flows along the outer surface S1a of the fixed vane 8a and is deflected in a direction parallel to the straight line L3. On the other hand, another portion of the airflow 50, 51b, passes from the upstream end 85a of the fixed vane 8a to the inner surface S2a. That is, the airflow 51b flows into the inner surface S2a along the tangent L4. At this time, the region between the airflow 51b and the inner surface S2a is under negative pressure relative to the surroundings, so the airflow 51b flows along the inner surface S2a and is deflected on the inner surface S2a side in a direction along the inner surface S2a (a direction that is deflected even more than the direction along the straight line L3). Then, downstream of the fixed vane 8a, the airflows 51a and 51b merge. At this time, turbulence in the airflow caused by the merging of airflows 51a and 51b is suppressed. The resulting airflow 52 flows into the swirling chamber 14 and, deflected by the multiple fixed vanes 8a, creates a swirling airflow.

[0070] As described above, the fixed vanes 8a constituting the ventilation hood 1a according to this second embodiment can provide the following benefits.

[0071] (4) In the ventilation hood 1a, the predetermined thickness of the linear section 81a is configured to become thinner from the upstream side (thickness T2) to the downstream side (thickness T1). As a result, at the downstream end 83a of the fixed vane 8a, the space between the airflow 51a flowing along the downstream end 83a on the outer surface S1 side of the fixed vane 8a and the airflow 51b flowing along the downstream end 83a on the inner surface S2 side of the fixed vane 8a is reduced, and turbulence caused by the intersecting airflows at the downstream end 83a of the fixed vane 8a is suppressed, thereby further reducing the pressure loss when generating a swirling airflow.

[0072] In other words, the airflow changes so that the airflow 51b flowing along the inner surface S2a of the fixed vane 8a becomes even more inclined than the airflow 31a with respect to the straight line L1 passing through the central axis 6. Furthermore, the thinning of the downstream end 83a suppresses turbulence in the airflow caused by the merging of airflows 51a and 51b. Thus, it is possible to maintain a swirling airflow while further reducing the pressure loss generated by the fixed vane 8a.

[0073] Although the present invention has been described above based on embodiments, it is easy to infer that the present invention is not limited in any way to the above embodiments, and that various improvements and modifications are possible without departing from the spirit of the present invention. For example, the numerical values ​​given in the above embodiments are just examples, and it is of course possible to use other numerical values. [Industrial applicability]

[0074] The cyclone separation device according to the present invention can reduce pressure loss when generating a swirling airflow, thereby reducing the power required for the blower. This makes it effective for separating foreign matter from the air supplied to houses where energy saving and quiet operation are required, and it is useful, for example, as a ventilation hood attached to an air intake on the exterior wall of a house. [Explanation of Symbols]

[0075] 1. Ventilation hood 1a Ventilation hood 2 Outflow pipe 3 Cover 4 Base plate 5 cabinets 6 center axis 7 Inlet 8 fixed blades 8a Fixed blade 8x Fixed Blades 9 Outlet 10 Emission promotion aspect 11 Discharge section 12 Outlet 13 Space dividing plate 14 Turning room 15 Separation room 16 Through holes 17 Inner tube 18 Inner tube end face 19 Square Separator 20 aperture 30 Airflow 31a Airflow 31b Airflow 32 Airflow 40 Airflow 41a Airflow 41b Airflow 42 Airflow 50 Airflow 51a Airflow 51b Airflow 52 Airflow 81 Straight line section 81a Linear section 82 Curved section 82a Curved section 83 End 83a end 84 End 84a end 85 End 85a end 85x end L1 straight line L2 straight line L3 straight line L4 tangent S1 External surface S1a External surface S2 Inner S2a Inner surface S3 exterior S4 Inner D1 angle A1 Cylindrical surface A2 cylindrical surface SA1 Negative pressure region T1 Thickness T2 Thickness 101 Fixed blades 102 Inlet 103 Turning room 104 Separation room

Claims

1. An inlet for bringing air into the enclosure, Multiple fixed vanes that generate a swirling airflow inside the housing by the air flowing in from the inlet, An outlet is provided on the rear of the housing, which causes the air that has flowed in from the inlet to flow out of the housing, A spatial dividing plate divides the interior of the housing into a swivel chamber located on the inner circumference side, which is in communication with the inlet and includes the center of the housing, and a separation chamber located on the outer circumference side of the swivel chamber. The spatial dividing plate is provided with a through hole that connects the separation chamber and the swivel chamber, With the central axis of the housing positioned horizontally, an outlet is provided at a position below the direction of gravity in the separation chamber, and communicates the separation chamber with the outside of the housing, Equipped with, Each of the plurality of fixed blades has a downstream end and an upstream end, and in the cross-sectional shape of the fixed blade in a plane normalized to the central axis of the swivel chamber, it has a linear portion of a predetermined thickness that is inclined at a predetermined angle with respect to a line connecting the central axis and the midpoint of the downstream end, and a curved portion that extends upstream from the linear portion, with the upstream end curving toward the outer surface of the fixed blade more than the linear portion. A cyclone separation device in which a plurality of fixed blades are arranged at predetermined intervals along the circumference of a cylinder centered on the central axis of the swivel chamber on the rear side of the swivel chamber.

2. The cyclone separation device according to claim 1, wherein the curved portion has a predetermined curvature, and the curve is such that the tangent line on the inner surface side of the fixed vane at the upstream end is parallel to a straight line connecting the central axis and the midpoint of the upstream end.

3. The cyclone separation device according to claim 1 or 2, wherein in the cross-sectional shape of the fixed vane, the length of the curved portion between the upstream and downstream sides is shorter than that of the straight portion.

4. The cyclone separation apparatus according to claim 1 or 2, wherein the predetermined thickness of the linear portion decreases from the upstream side to the downstream side of the linear portion.

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