JP7248298B2 - Exhaust duct and outside air intake unit - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act Publication date: August 30, 2019 Publication location: Pier House Oasis (1st floor, Kobe Port Oasis, 5-2 Shinko-cho, Chuo-ku, Kobe-shi, Hyogo)

TECHNICAL FIELD The present invention relates to an exhaust duct and an outside air introduction unit incorporated in the exhaust duct.

Exhaust air from kitchens of restaurants, food factories, and the like is released into the atmosphere through exhaust ducts that extend from indoors to outdoors. The exhaust may be accompanied by an odor, and there is a concern that if an odor that people find unpleasant, ie, exhaust with a bad smell, is released into the atmosphere, it will cause sensory pollution in the neighborhood that stimulates the human senses.

In order to prevent this, it is effective to diffuse and dilute the odor in the exhaust air. For this reason, conventionally, the exhaust duct is extended long upward, the exhaust port of the exhaust duct is provided at a position as high as possible, or the discharge speed of the exhaust gas from the exhaust port is increased so that the exhaust gas reaches the position as high as possible. there is

However, in a configuration in which the exhaust port is provided at a high position, reinforcement of the exhaust duct is required. Also, in a configuration for increasing the discharge speed of the exhaust air, an exhaust fan with a large flow rate is required. Both of these configurations are therefore costly. Moreover, in both configurations, the odor in the exhaust gas is diluted with the air after the exhaust gas is discharged from the exhaust port. , its odorous exhaust may flow to nearby areas.

Therefore, a configuration has been proposed in which an outside air introduction duct is connected in the middle of the exhaust duct, and the outside air (atmosphere) is introduced into the exhaust duct through the outside air introduction duct (see, for example, Patent Document 1). However, even if the external air introduction duct is simply connected to the exhaust duct, the external air is not taken in by the external air introduction duct, and conversely, there is a risk that the exhaust air will be discharged into the atmosphere through the external air introduction duct. Therefore, in the proposed configuration, a booster fan is provided in the outside air introduction duct, and the outside air is forcibly introduced from the outside air introduction duct to the exhaust duct by the operation of this booster fan. In addition, in order to prevent exhaust air from flowing from the exhaust duct to the outside air introduction duct, a backflow prevention damper is provided in the middle of the outside air introduction duct.

JP-A-11-83106

According to such a configuration, outside air can be mixed with exhaust gas in the exhaust duct. However, since a booster fan and damper are required, the cost is high. In addition, if the amount of air flowing from the outside air introduction duct to the exhaust duct is large due to the booster fan, the amount of exhaust air flowing through the exhaust duct will decrease. The exhaust capacity from is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an exhaust duct and an outside air introduction unit that have a low-cost configuration and can effectively dilute exhaust air with outside air.

In order to achieve the above object, an exhaust duct according to one aspect of the present invention is an exhaust duct for discharging exhaust air from an exhaust fan into the atmosphere, and has a cylindrical outer periphery having a center line extending in the exhaust flow direction. and a dividing wall portion provided in the outer peripheral wall portion for partitioning an exhaust flow path through which exhaust gas from the exhaust fan circulates in the flow direction, and the downstream end of the exhaust flow path in the flow direction is located inside the outer peripheral wall portion. At least a portion of the open end is separated from the inner surface of the outer peripheral wall portion, and the outer peripheral wall portion has a portion spaced apart from at least a portion of the open end, An outside air inlet is formed in the outer peripheral wall for taking in the outside air.

According to this configuration, the partition wall portion is provided in the cylindrical outer peripheral wall portion, and the partition wall portion partitions the exhaust passage through which the exhaust air from the exhaust fan flows. A downstream end of the exhaust passage in the exhaust flow direction is opened as an open end within the outer peripheral wall portion, and at least a part of the open end is separated from the inner surface of the outer peripheral wall portion. Therefore, in the outer peripheral wall portion, an airflow of the exhaust gas is formed on the downstream side in the flow direction of the exhaust channel, away from the inner surface of the outer peripheral wall portion and flowing out from the opening end of the exhaust channel. Air (fluid) between the airflow and the outer peripheral wall is drawn into the airflow by the Coanda effect. Since the outside air intake port is formed in a portion of the outer peripheral wall portion that is spaced apart from at least a portion of the opening end, the air between the airflow and the outer peripheral wall portion is drawn into the airflow. A negative pressure is generated between the outside wall and the outside air, and the outside air is taken into the inside of the outside wall through the outside air intake port. As a result, outside air is drawn into the airflow of the exhaust from the open end of the exhaust passage, and the exhaust is diluted with the outside air.

Therefore, it is possible to effectively dilute the exhaust gas with outside air with a low-cost configuration without requiring power (electric power). Therefore, even if the exhaust gas accompanies an odor, the odor is diluted by the outside air, so that the exhaust gas released into the atmosphere can eliminate the possibility of sensory pollution in the neighborhood.

The outer peripheral wall portion may be formed in a square tubular shape having a first outer wall portion and a second outer wall portion facing each other and a third outer wall portion and a fourth outer wall portion facing each other. In this case, the partition wall may have a first inner wall portion extending from the first outer wall portion, and the outside air intake may be formed in the first outer wall portion, or the partition wall portion may extend from the first outer wall portion. It may have a spaced apart first inner wall portion and a second inner wall portion spaced apart from the second outer wall portion, and the outside air intake may be formed in the first and second outer wall portions.

When the exhaust duct is installed so that the center line of the outer peripheral wall portion extends horizontally or at an angle, by directing the first outer wall portion and the second outer wall portion to the side, rainwater and the like falling on the exhaust duct from above can be prevented. It is possible to suppress entry of the outside air intake port, and it is possible to suppress downward leakage of oil or the like adhering to the inner surface of the outer peripheral wall portion from the outside air intake port.

The outside air intake is formed in a rectangular shape, and a plurality of outside air intakes are formed in each of the first outer wall and the second outer wall in a line in the direction of circulation, and the most upstream outside air intake in the direction of circulation is provided. A partition wall portion may be connected to the edge of the outlet on the upstream side in the flow direction.

The outside air intake is formed in a rectangular shape, and a plurality of outside air intakes are formed in each of the first outer wall and the second outer wall so as to be aligned in the direction of circulation. A plate-shaped plate connected to an upstream edge in the flow direction of an outside air intake on the downstream side of the upstream outside air intake and extending from the edge toward a space on the downstream side in the flow direction of the open end. The configuration may further include a guide portion.

An outside air introduction unit according to another aspect of the present invention includes a cylindrical outer peripheral wall portion having a center line extending in an exhaust flow direction, and is attached to an exhaust duct that releases exhaust air from an exhaust fan into the atmosphere. An outside air introduction unit that introduces outside air into the wall, has an outer shape along the periphery of the mounting opening formed in the outer wall, and is fixed to the periphery of the mounting opening in the outer wall. and one end is fixed to the upstream end of the fixed part in the flow direction, and is inclined downstream in the flow direction with respect to the direction in which the center line extends from the fixed part to the inside of the outer peripheral wall. An outside air intake port for taking outside air into the outer peripheral wall is formed in a portion surrounded by the fixed portion including the extending plate-like partition wall.

By attaching this outside air introduction unit to the exhaust duct, it is possible to achieve the same effect as the exhaust duct according to one aspect of the present invention.

The outside air introduction unit further includes a plate-shaped guide portion that extends inclined downstream in the flow direction with respect to the direction in which the center line extends from the fixed portion to the inside of the outer peripheral wall portion, and the outside air intake port is located in the partition wall portion. and the guide portion.

ADVANTAGE OF THE INVENTION According to this invention, exhaust gas can be effectively diluted with outside air by a low-cost structure, without requiring power (electric power).

It is a figure which shows typically the structure of the exhaust apparatus by which the exhaust duct which concerns on one Embodiment of this invention was incorporated. 1 is a perspective view of an exhaust duct according to one embodiment of the present invention; FIG. Figure 3 is a side view of the exhaust duct shown in Figure 2; Figure 3 is a plan view of the exhaust duct shown in Figure 2; 5 is a cross-sectional view of the exhaust duct taken along the cutting plane line AA shown in FIG. 4; FIG. FIG. 5 is a perspective view showing the configuration of an outside air introduction unit according to another embodiment of the present invention; FIG. 4 is a plan view of the exhaust duct to which the outside air introduction unit is attached (a view viewed from the downstream side in the direction of flow toward the center line). FIG. 11 is a plan view of an exhaust duct according to a modification; FIG. 9 is a cross-sectional view of the exhaust duct taken along the cutting plane line BB shown in FIG. 8; FIG. 11 is a cross-sectional view of an exhaust duct according to another modified example; FIG. 11 is a cross-sectional view of an exhaust duct according to still another modification;

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Exhaust device>
FIG. 1 is a diagram schematically showing the configuration of an exhaust device 1 incorporating an exhaust duct 2A according to one embodiment of the present invention.

An exhaust system 1 is, for example, a device (equipment) for releasing exhaust air from a kitchen of a restaurant to the outside, and includes a plurality of exhaust ducts 2, an exhaust fan 3, and a volume damper (VD) 4 for adjusting the air volume. . A plurality of exhaust ducts 2 are spliced together to form one exhaust air passage. One end of the exhaust air duct is open as an air intake in the kitchen, and the other end is open to the outdoors. The exhaust fan 3 and the volume damper 4 are interposed in the middle of the exhaust air passage. By the operation of the exhaust fan 3, the air in the kitchen is sucked into the exhaust duct 2, and the exhaust air from the kitchen is circulated through the exhaust duct 2 to the outside. The volume damper 4 is provided downstream of the exhaust fan 3 in the blowing direction of the exhaust fan 3 , that is, in the direction of exhaust flow in the exhaust duct 2 (hereinafter simply referred to as the “flow direction”).

One of the plurality of exhaust ducts 2 includes an exhaust duct 2A for diluting the exhaust with the outside air. The exhaust duct 2A is preferably provided downstream of the volume damper 4 in the flow direction, and more preferably at the downstream end of the exhaust air passage in the flow direction.

<Exhaust duct>
FIG. 2 is a perspective view of the exhaust duct 2A. FIG. 3 is a side view of the exhaust duct 2A. FIG. 4 is a plan view of the exhaust duct 2A. FIG. 5 is a cross-sectional view of the exhaust duct 2A along the cutting plane line AA shown in FIG.

The exhaust duct 2A is made of, for example, SECC (electrogalvanized steel plate) or SUS (stainless steel plate). The exhaust duct 2A has an outer peripheral wall portion 11 and a partition wall portion 12 .

The outer peripheral wall portion 11 has a rectangular tubular shape having a first outer wall portion 21 , a second outer wall portion 22 , a third outer wall portion 23 and a fourth outer wall portion 24 . The first outer wall portion 21 and the second outer wall portion 22 are each formed in a rectangular plate shape and extend in a direction parallel to the center line of the outer peripheral wall portion 11 (hereinafter, in the description of the exhaust duct 2A, the direction is referred to as the "center line direction"). ) and face each other in a direction perpendicular to the centerline direction. Each of the third outer wall portion 23 and the fourth outer wall portion 24 is formed in a rectangular plate shape, extends in the center line direction, and is perpendicular to both the opposing direction of the first outer wall portion 21 and the second outer wall portion 22 and the center line direction. facing each other in the direction of One end edge and the other end edge of the third outer wall portion 23 extending in the centerline direction are connected to the first outer wall portion 21 and the second outer wall portion 22, respectively. Further, one end edge and the other end edge of the fourth outer wall portion 24 extending in the centerline direction are connected to the first outer wall portion 21 and the second outer wall portion 22, respectively. At both ends of the outer peripheral wall portion 11 in the center line direction, flange portions 25 projecting outward are formed for connection with another exhaust duct 2 .

The partition wall portion 12 has a first inner wall portion 31 , a second inner wall portion 32 , a third inner wall portion 33 and a fourth inner wall portion 34 . The first inner wall portion 31, the second inner wall portion 32, the third inner wall portion 33 and the fourth inner wall portion 34 are the first outer wall portion 21, the second outer wall portion 22, the third outer wall portion 23 and the fourth outer wall portion 24, respectively. It is fixed to the inner surface and has a plate shape extending from the inner surface toward the center line of the outer peripheral wall portion 11 .

The first inner wall portion 31 narrows from the full width in the width direction perpendicular to the center line direction of the inner surface of the first outer wall portion 21 toward the tip, and is It extends obliquely to the downstream side in the flow direction, bends in the middle and further extends to the downstream side in the flow direction.

The second inner wall portion 32 narrows from the full width in the width direction perpendicular to the center line direction of the inner surface of the second outer wall portion 22 toward the tip so that the dimension in the width direction decreases with respect to the center line direction. It extends obliquely to the downstream side in the flow direction, bends in the middle and further extends to the downstream side in the flow direction.

The third inner wall portion 33 narrows from the full width in the width direction perpendicular to the center line direction of the inner surface of the third outer wall portion 23 toward the tip so that the dimension in the width direction decreases toward the center line direction. It extends obliquely to the downstream side in the flow direction, bends in the middle and further extends to the downstream side in the flow direction.

The fourth inner wall portion 34 narrows from the full width in the width direction perpendicular to the center line direction of the inner surface of the fourth outer wall portion 24 toward the tip so that the dimension in the width direction decreases with respect to the center line direction. It extends obliquely to the downstream side in the flow direction, bends in the middle and further extends to the downstream side in the flow direction.

The upstream ends of the first inner wall portion 31, the second inner wall portion 32, the third inner wall portion 33, and the fourth inner wall portion 34 in the flow direction are positioned at the same position in the centerline direction. In addition, the bent portions of the first inner wall portion 31, the second inner wall portion 32, the third inner wall portion 33, and the fourth inner wall portion 34 are located at the same position in the center line direction. The downstream ends of the second inner wall portion 32, the third inner wall portion 33, and the fourth inner wall portion 34 in the flow direction are located at the same position in the centerline direction. An edge on one side and an edge on the other side in the width direction of the third inner wall portion 33 are connected to the first inner wall portion 31 and the second inner wall portion 32, respectively. The edge on one side and the edge on the other side in the width direction of the fourth inner wall portion 34 are connected to the first inner wall portion 31 and the second inner wall portion 32, respectively.

As a result, the partition wall portion 12 is formed in a shape in which a truncated pyramid shape with a relatively small base angle and a truncated pyramid shape with a relatively large base angle are stacked in the flow direction. It defines an exhaust passage 35 through which the exhaust from the fan 3 (see FIG. 1) flows. The downstream end of the exhaust flow path 35 in the flow direction is positioned upstream of the downstream end of the outer peripheral wall portion 11 in the flow direction and is open as an open end 36 .

Outside air intake ports 41, 42, and 43 are provided in the first outer wall portion 21 in this order from the upstream side in the flow direction and arranged at equal intervals in the center line direction. In the second outer wall portion 22, external air intake ports 44, 45, and 46 are arranged in this order from the upstream side in the flow direction and arranged at equal intervals in the center line direction. The outside air intake ports 41 to 46 are all formed in a rectangular shape elongated in the width direction and of the same size. The first inner wall portion 31 and the second inner wall portion 32 are connected to edges of the outside air intake ports 41 and 44 on the upstream side in the flow direction, respectively.

Guide portions 51 and 52 are provided on the inner surface of the first outer wall portion 21 . The guide portion 51 extends across the entire width of the inner surface of the first outer wall portion 21 in the width direction along the edge of the outside air intake port 42 on the upstream side in the flow direction, and extends downstream in the flow direction with respect to the center line direction. It is formed in a plate shape extending obliquely. A space is provided between the tip of the guide portion 51 and the partition wall portion 12 (the first inner wall portion 31). The guide portion 52 extends across the entire width of the inner surface of the first outer wall portion 21 in the width direction along the edge of the outside air intake 43 on the upstream side in the flow direction, and extends downstream in the flow direction with respect to the center line direction. It is formed in a plate shape extending obliquely. The tip portion of the guide portion 52 is bent downstream in the flow direction at a position overlapping the tip edge of the guide portion 51 when viewed in the centerline direction, and extends in the centerline direction so that the inner surface of the first outer wall portion 21 and the centerline It faces in the direction perpendicular to the direction.

Guide portions 53 and 54 are provided on the inner surface of the second outer wall portion 22 . The guide portion 53 extends across the entire width of the inner surface of the second outer wall portion 22 in the width direction along the edge of the outside air intake 45 on the upstream side in the flow direction, and extends downstream in the flow direction with respect to the center line direction. It is formed in a plate shape extending obliquely. A space is provided between the tip of the guide portion 53 and the partition wall portion 12 (second inner wall portion 32). The guide portion 54 extends across the entire width of the inner surface of the second outer wall portion 22 in the width direction along the edge of the outside air intake port 46 on the upstream side in the flow direction, and extends downstream in the flow direction with respect to the center line direction. It is formed in a plate shape extending obliquely. The tip portion of the guide portion 54 is bent downstream in the flow direction at a position overlapping the tip edge of the guide portion 52 when viewed in the centerline direction, and extends in the centerline direction so that the inner surface of the second outer wall portion 22 and the centerline It faces in the direction perpendicular to the direction.

In this embodiment, the exhaust duct 2A is formed symmetrically with respect to the center line of the outer peripheral wall portion 11 in the direction in which the first outer wall portion 21 and the second outer wall portion 22 face each other. It is formed symmetrically in the facing direction with the outer wall portion 24 .

<Effect>
As described above, the partition wall portion 12 is provided in the tubular outer peripheral wall portion 11 , and the partition wall portion 12 partitions the exhaust passage 35 through which the exhaust air from the exhaust fan 3 flows. A downstream end of the exhaust flow path 35 in the flow direction is open as an open end 36 within the outer peripheral wall portion 11 , and the open end 36 is separated from the inner surface of the outer peripheral wall portion 11 . Therefore, in the outer peripheral wall portion 11, on the downstream side in the flow direction of the exhaust flow path 35, an airflow of exhaust gas is formed away from the inner surface of the outer peripheral wall portion 11 and flowing out from the opening end 36 of the exhaust flow path 35. . Air (fluid) between the airflow and the outer peripheral wall portion 11 is drawn into the airflow by the Coanda effect. Since the outside air intake ports 41 to 46 are formed in the outer peripheral wall portion 11 , the air between the air flow and the outer peripheral wall portion 11 is drawn into the air flow, so that the air between the air flow and the outer peripheral wall portion 11 is drawn into the air flow. A negative pressure is generated, and the negative pressure draws outside air into the outer peripheral wall portion 11 through the outside air intake ports 41 to 46 . As a result, outside air is drawn into the airflow of the exhaust from the open end 36 of the exhaust passage 35, and the exhaust is diluted with the outside air.

Therefore, it is possible to effectively dilute the exhaust gas with outside air with a low-cost configuration without requiring power (electric power). Therefore, even if the exhaust gas accompanies an odor, the odor is diluted by the outside air, so that the exhaust gas released into the atmosphere can eliminate the possibility of sensory pollution in the neighborhood.

The outer peripheral wall portion 11 has a first outer wall portion 21 and a second outer wall portion 22 facing each other, and a third outer wall portion 23 and a fourth outer wall portion 24 facing each other. The partition wall portion 12 has a first inner wall portion 31 separated from the first outer wall portion 21 and a second inner wall portion separated from the second outer wall portion 22. It is formed in the first outer wall portion 21 and the second outer wall portion 22 .

When the exhaust duct 2A is installed so that the center line of the outer peripheral wall portion 11 extends horizontally or inclined, by directing the first outer wall portion 21 and the second outer wall portion 22 sideways, the exhaust duct 2A can be positioned upwardly. It is possible to suppress rainwater falling from outside into the air intake ports 41 to 46, and to suppress oil adhered to the inner surface of the outer peripheral wall portion 11 from leaking downward from the outside air intake ports 41 to 46. - 特許庁

Guide portions 51 and 52 are provided on the inner surface of the first outer wall portion 21 , and guide portions 53 and 54 are provided on the inner surface of the second outer wall portion 22 . The guide portions 51 and 53 are plate-shaped and extend from the edges of the air intake ports 42 and 45 on the upstream side in the direction of flow, respectively, with an inclination toward the downstream side in the direction of flow with respect to the centerline direction. The first inner wall portion 31 and the second inner wall portion 32 extend obliquely to the downstream side in the flow direction with respect to the center line direction, bend halfway to the downstream side in the flow direction, and further extend. As a result, a large cross-sectional area between the first inner wall portion 31 and the guide portion 51 and a cross-sectional area between the second inner wall portion 32 and the guide portion 53 can be ensured. It is possible to increase the intake of outside air into 11 .

The tip portions of the guide portions 51 and 53 are not bent, and the tip portions of the guide portions 52 and 54 are bent downstream in the flow direction and extend in the centerline direction. As a result, a large contact area can be ensured between the outside air taken into the outer peripheral wall portion 11 through the outside air intake ports 42 and 45 and the exhaust airflow from the opening end 36 of the exhaust passage 35, and the Coanda effect is exhibited satisfactorily. be able to. In addition, the outside air taken into the outer peripheral wall portion 11 from the outside air intake ports 43 and 46 can be guided in the center line direction by the tip portions of the guide portions 52 and 54, and the outside air is directed to the inner peripheral surface of the outer peripheral wall portion 11. A centerline airflow can be formed.

The first inner wall portion 31, the guide portions 51, 52, the second inner wall portion 32, and the guide portions 53, 54 are connected to the upstream edges of the outside air intake ports 41 to 46 in the flow direction, respectively. Therefore, it is possible to prevent oil and dust from accumulating in the connecting portion.

<Outside air introduction unit>
FIG. 6 is a perspective view showing the configuration of an outside air introduction unit 101 according to another embodiment of the invention. FIG. 7 is a plan view of the exhaust duct 2 to which the outside air introduction unit 101 is attached (viewed from the downstream side in the direction of flow toward the center line).

The outside air introduction unit 101 is a unit that is attached to the existing exhaust duct 2 and introduces outside air into the exhaust duct 2 . The exhaust duct 2 to which the outside air introduction unit 101 is attached is preferably provided downstream of the volume damper 4 in the direction of flow.

The exhaust duct 2 has a rectangular tubular shape having a first outer wall portion 111 , a second outer wall portion 112 , a third outer wall portion 113 and a fourth outer wall portion 114 . The first outer wall portion 111 and the second outer wall portion 112 are each formed in a rectangular plate shape and extend in a direction parallel to the center line of the exhaust duct 2 (hereinafter, in the description of the outside air introduction unit 101, the direction is referred to as the “center line direction”). ) and face each other in a direction perpendicular to the centerline direction. The third outer wall portion 113 and the fourth outer wall portion 114 are each formed in a rectangular plate shape, extend in the center line direction, and are perpendicular to both the facing direction of the first outer wall portion 111 and the second outer wall portion 112 and the center line direction. facing each other in the direction of One end edge and the other end edge of the third outer wall portion 113 extending in the centerline direction are connected to the first outer wall portion 111 and the second outer wall portion 112, respectively. Further, one end edge and the other end edge of the fourth outer wall portion 114 extending in the centerline direction are connected to the first outer wall portion 111 and the second outer wall portion 112, respectively. At both ends of the outer peripheral wall portion 11 in the center line direction, flange portions 115 projecting outward are formed for connection with another exhaust duct 2 .

In the following, when referring to directions, the state in which the outside air introduction unit 101 is attached to the exhaust duct 2 is used as a reference.

The outside air introduction unit 101 includes a fixed portion 121 , side plate portions 122 and 123 , a partition wall portion 124 and guide portions 125 and 126 .

The fixed portion 121 is formed in a rectangular frame shape.

The side plate portions 122 and 123 protrude from one surface of one end and the other end of the fixing portion 121 in the width direction orthogonal to the center line direction and extend in the center line direction.

The partition wall portion 124 is provided between the side plate portions 122 and 123 . The partition wall portion 124 has a plate-like shape, one end of which is fixed to the upstream end of the fixed portion 121 in the flow direction, and the fixed portion extends into the outer peripheral wall portion 11 in the flow direction with respect to the center line direction. extends at an angle to the downstream side of the A tip portion of the partition wall portion 124 is bent downstream in the flow direction and extends in the centerline direction. In addition, the partition wall portion 124 is formed to have the same width as the inner peripheral edge of the fixing portion 121 in the width direction orthogonal to the center line direction.

The guide portion 125 is provided between the side plate portions 122 and 123 with a space therebetween on the downstream side in the flow direction with respect to the partition wall portion 124 . The guide part 125 has a plate shape and extends so as to be inclined downstream in the flow direction with respect to the centerline direction. The end portion of the guide portion 125 on the fixed portion 121 side is bent toward the upstream side in the flow direction and extends in the center line direction. An end portion of the guide portion 125 opposite to the fixing portion 121 side is bent downstream in the flow direction and extends in the centerline direction. Both ends of the guide portion 125 in the width direction are connected to the side plate portions 122 and 123 and fixed to the side plate portions 122 and 123 .

The guide portion 126 is provided between the side plate portions 122 and 123 with a space therebetween on the downstream side of the flow direction with respect to the guide portion 125 . The guide portion 126 has a plate shape and extends so as to be inclined downstream in the flow direction with respect to the centerline direction. The end portion of the guide portion 126 on the side of the fixed portion 121 is arranged with a gap from the end portion of the fixed portion 121 on the upstream side in the flow direction, is bent toward the upstream side in the flow direction, and extends in the center line direction. ing. An end portion of the guide portion 126 opposite to the fixing portion 121 side is bent downstream in the flow direction and extends in the centerline direction. Both ends of the guide portion 126 in the width direction are connected to the side plate portions 122 and 123 and fixed to the side plate portions 122 and 123 .

In the region surrounded by fixed portion 121, outside air intake ports 131, 132, and 133 are provided between partition wall portion 124 and guide portion 125, between guide portions 125 and 126, and between guide portion 126 and fixed portion 121, respectively. It is open.

The first outer wall portion 111 and the second outer wall portion 112 of the exhaust duct 2 are formed with rectangular mounting openings 134 and 135 corresponding to the fixing portion 121 of the outside air introduction unit 101, respectively. The side plate portions 122 and 123, the partition wall portion 124 and the guide portions 125 and 126 of the outside air introduction unit 101 are fitted into the mounting openings 134 and 135 from the outside of the exhaust duct 2, and the fixing portion 121 is mounted on the first outer wall portion 111. The outside air introduction unit 101 is attached to the exhaust duct 2 by being fixed in contact with the peripheral edge portion of the opening 134 and the peripheral edge portion of the attachment opening 135 of the second outer wall portion 112 .

<Effect>
In a state where the two outside air introduction units 101 are attached to the exhaust duct 2, the partition wall portion 124 of one outside air introduction unit 101 and the partition wall portion 124 of the other outside air introduction unit 101 are perpendicular to the center line direction. facing each other. The flow velocity of the exhaust air from the exhaust fan 3 (see FIG. 1) increases as it passes through the partition walls 124 facing each other. As a result, on the downstream side in the flow direction between the partition walls 124, an airflow of the exhaust gas is formed that flows out from between the partition walls 124 away from the first outer wall 111 and the second outer wall 112 of the exhaust duct 2. be.

Air (fluid) between the airflow and the first outer wall portion 111 and the second outer wall portion 112 is drawn into the airflow by the Coanda effect. Since outside air intake ports 131 to 133 are formed in the area surrounded by the fixing portion 121, the air between the airflow and the first outer wall portion 111 and the second outer wall portion 112 is drawn into the airflow. A negative pressure is generated between the airflow and the first outer wall portion 111 and the second outer wall portion 112, and the negative pressure draws outside air into the outer peripheral wall portion 11 through the outside air intake ports 41-46. As a result, outside air is drawn into the airflow of the exhaust from the open end 36 of the exhaust passage 35, and the exhaust is diluted with the outside air.

Therefore, it is possible to effectively dilute the exhaust gas with outside air with a low-cost configuration without requiring power (electric power). Therefore, even if the exhaust gas accompanies an odor, the odor is diluted by the outside air, so that the exhaust gas released into the atmosphere can eliminate the possibility of sensory pollution in the neighborhood. In addition, the same effect as the configuration of the exhaust duct 2A can be obtained.

<Modification>
Although two embodiments of the present invention have been described above, the present invention can also be implemented in other forms.

For example, as shown in FIGS. 8 and 9, the second inner wall portion 32, the third inner wall portion 33 and the fourth inner wall portion 34 of the partition wall portion 12, the outside air intakes 44, 45 and 46 and the guide portion 53, 54 is not formed, and the exhaust passage 35 is partitioned by the first inner wall portion 31 of the partition wall portion 12 and the second outer wall portion 22, the third outer wall portion 23 and the fourth outer wall portion 24 of the outer peripheral wall portion 11. good too.

The configurations shown in FIGS. 8 and 9 can also effectively dilute exhaust gas with outside air without requiring power (electric power) with a low-cost configuration. However, if the configuration shown in FIGS. 8 and 9 has the same dimensions as the configuration shown in FIG. 2, the configuration shown in FIG. can take in a large amount of outside air.

As shown in FIG. 10, the guides 52, 54 may be omitted. Also, all the guides 51 to 54 may be omitted.

Further, as shown in FIG. 11, folded portions having a substantially triangular cross section are formed on the inner surface of the first outer wall portion 21 along the upstream ends of the guide portions 51 and 52 and the outside air intake port 43 in the flow direction. 201 may be formed. In addition, folded portions 202 having a substantially triangular cross section may be formed along the upstream ends of the guide portions 53 and 54 and the outside air intake 46 in the flow direction on the inner surface of the second outer wall portion 22 . . As a result, the outside air taken in from the outside air intake ports 41 to 46 is guided toward the airflow of the exhaust gas from the exhaust passage 35, and the outside air can be well introduced into the airflow. Further, the folded portions 201 and 202 can reinforce the first outer wall portion 21 and the second outer wall portion 22, respectively.

Further, in the above-described embodiment, the exhaust duct 2A is preferably provided downstream of the volume damper 4 in the flow direction. When the exhaust duct 2A is provided upstream of the volume damper 4 in the flow direction, the exhaust duct 2A is placed in a pressurized state, and the amount of outside air taken in from the outside air intake ports 41 to 46 is reduced. , the effect of dilution of the exhaust by outside air may be diminished. Further, when the exhaust duct 2A is provided on the upstream side of the exhaust fan 3 in the flow direction, the odor generated from the oil and the like adhering to the inner surface of the exhaust duct 2 provided on the downstream side of the flow direction of the exhaust fan 3 is produced. May be released into the atmosphere without being well diluted. The position of the exhaust duct 2 to which the outside air introduction unit 101 is attached is similar to that of the exhaust duct 2A.

In addition, various design changes can be made to the above configuration within the scope of the matters described in the claims.

2, 2A: exhaust duct 3: exhaust fan 11: outer wall portion 12, 124: partition wall portion 21, 111: first outer wall portion 22, 112: second outer wall portion 23, 113: third outer wall portion 24, 114: Fourth outer wall portion 31: First inner wall portion 32: Second inner wall portion 35: Exhaust flow path 36: Open end 41 to 46, 131 to 133: Outside air intake 51 to 54, 125, 126: Guide portion 101: Outside air Introduction unit 121: Fixed part 134, 135: Mounting opening

Claims (4)

An exhaust duct for releasing exhaust from an exhaust fan into the atmosphere,
a cylindrical outer wall portion having a center line extending in the direction of flow of exhaust gas;
a partition wall portion provided in the outer peripheral wall portion and partitioning an exhaust flow path through which exhaust gas from the exhaust fan circulates in a distribution direction;
The outer peripheral wall portion is formed in a square tube shape having a first outer wall portion and a second outer wall portion facing each other and a third outer wall portion and a fourth outer wall portion facing each other,
The partition wall has a first inner wall extending from the first outer wall,
A downstream end of the exhaust flow path in the flow direction is open as an open end within the outer peripheral wall,
At least part of the open end is separated from the inner surface of the outer peripheral wall,
The first outer wall portion of the outer peripheral wall portion is formed with a square-shaped outside air intake port for taking in outside air into the outer peripheral wall portion in a portion spaced apart from at least a part of the open end,
The exhaust duct, wherein the partition wall portion is connected to an upstream edge in the flow direction of the outside air intake port. An exhaust duct for releasing exhaust from an exhaust fan into the atmosphere,
a cylindrical outer wall portion having a center line extending in the direction of flow of exhaust gas;
a partition wall portion provided in the outer peripheral wall portion and partitioning an exhaust flow path through which exhaust gas from the exhaust fan circulates in a distribution direction;
The outer peripheral wall portion is formed in a square tube shape having a first outer wall portion and a second outer wall portion facing each other and a third outer wall portion and a fourth outer wall portion facing each other,
The partition wall has a first inner wall extending from the first outer wall,
A downstream end of the exhaust flow path in the flow direction is open as an open end within the outer peripheral wall,
At least part of the open end is separated from the inner surface of the outer peripheral wall,
The first outer wall portion of the outer peripheral wall portion is formed with a square-shaped outside air intake port for taking in outside air into the outer peripheral wall portion in a portion spaced apart from at least a part of the open end,
A plate connected to an upstream edge in the flow direction of the outside air intake and extending from the edge toward the open end or toward a space downstream of the open end in the flow direction. an exhaust duct further comprising a shaped guide. A plurality of the outside air intake ports are formed side by side in the flow direction in the outer peripheral wall,
The partition wall portion is connected to an upstream edge in the flow direction of the most upstream outside air intake port in the flow direction,
3. The exhaust gas according to claim 2, wherein the guide portion is connected to an upstream edge in the flow direction of the outside air intake port downstream of the most upstream outside air intake port in the flow direction. duct. The partition wall has a second inner wall spaced apart from the second outer wall,
The exhaust duct according to any one of claims 1 to 3 , wherein the outside air intake port is formed in the first outer wall portion and the second outer wall portion.

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