JP2022162264A - Local ventilator - Google Patents

Abstract

To uniformize speed distribution along a circumferential direction of swirling airflow to improve local ventilation performance.SOLUTION: A local ventilator 100 includes: an air suction port X1 which is open facing downward; and an air discharge port X2 which is provided around the air suction port X1 and discharges air while causing air to swirl to the oblique lower side. The local ventilator 100 includes: an exhaust passage L1 which communicates with the air suction port X1 and exhausts air suctioned from the air suction port X1; an air supply passage L2 which is formed around the exhaust passage L1 and communicates with the air discharge port X2 to guide air to the air discharge port X2; and a multi-hole punched distributing plate 70 which is provided at the upstream side of the air discharge port X2 in the air supply passage L2 and having multiple holes 70h or slits 70s which allow air to pass to an outer periphery part.SELECTED DRAWING: Figure 2

Description

The present invention relates to local ventilation devices.

In recent years, electric heating cookers that do not use fire have become popular, and these electric heating cookers are characterized by being easy to clean because the top surface is composed of a flat panel. .

On the other hand, compared to gas cookers, electric heating cookers have a lower updraft speed of air containing oily smoke generated from the heating object, and if the oily smoke does not reach the collection range of the upper ventilation device, it will spread inside the room. There is a problem that the indoor environment and the human body are adversely affected. Of course, if the amount of ventilation air is increased, the collection range can be expanded, but in this case, another problem arises in that noise and vibration increase and cause discomfort to the user.

Therefore, there is a local ventilator as shown in Patent Document 1 as a device for preventing the diffusion of oily smoke while maintaining the ventilation air volume.

Specifically, in this local ventilation system, a large number of air discharge ports are provided around an air suction port facing downward, and air is discharged obliquely downward from these many air discharge ports to create a whirling air current. This produces a local ventilation function.

As described above, the local ventilation function of the local ventilation system depends on how well the swirling airflow is generated. , the rectified air is directed to the air outlet.

However, in such a rectifying structure consisting of two annular rectifying plates, it is not possible to obtain a rectifying effect on the velocity distribution along the circumferential direction of the airflow. The velocity distribution along the circumferential direction of the airflow deteriorates. As a result, the swirling flow becomes unstable, and sufficient local ventilation performance cannot be exhibited.

Patent No. 6546476

Therefore, the present invention has been made to solve the above-mentioned problems at once, and the main object thereof is to improve the local ventilation performance by equalizing the velocity distribution of the swirling airflow along the circumferential direction. It is something to do.

That is, the local ventilator according to the present invention includes an air suction port that opens downward, and an air discharge port that is provided around the air suction port and discharges air while swirling it obliquely downward. an exhaust passage communicating with the air suction port for discharging the air sucked from the air suction port; and a multi-hole straightening plate provided on the upstream side of the air discharge port in the air supply passage and having a plurality of holes or slits formed on the outer periphery for allowing air to pass through. and

According to the local ventilator configured in this way, since it is equipped with a multi-hole straightening plate having a plurality of holes or slits for allowing air to pass through the outer periphery, when the air passes through these holes or slits, can be smoothed while erasing the velocity component along the circumferential direction to some extent. As a result, the velocity distribution along the circumferential direction of the whirling airflow, which is the air discharged from the air discharge port, can be made uniform, and the local ventilation performance can be improved.

It is preferable to further include an annular straightening plate provided downstream of the multi-hole straightening plate and having an air passage hole formed in the central portion thereof for allowing air to pass through.
With such a configuration, not only the velocity distribution along the circumferential direction but also the velocity distribution directed downward can be made uniform by the annular current plate.

an air supply/exhaust chamber comprising an inner casing having an internal space formed as the exhaust flow path, and an outer casing provided outside the inner casing and forming the air supply flow path between the inner casing; A hole straightening plate is provided from the inner peripheral surface of the outer casing to the outer peripheral surface of the inner casing, and the annular straightening plate extends from the inner peripheral surface of the outer casing toward the outer peripheral surface of the inner casing. It preferably extends and is provided with a gap from the outer peripheral surface of the inner casing.
With such a configuration, when the air passes through the holes or slits of the multi-hole straightening plate, the velocity component along the circumferential direction is made uniform, and when the air flows along the annular straightening plate, it travels downward. Velocity components can be homogenized.

It is preferable to further include an air supply duct connected from the radially outer side of the outer casing to supply air to the air supply channel from the side.
With such a configuration, it is possible to swirl the air supplied to the air supply passage, so it is possible to secure a sufficient air volume of the swirling airflow formed by the air being discharged from the air outlet, thereby improving the local ventilation performance. can be secured.

As a more specific embodiment, an exhaust duct connected to the upper portion of the inner casing may be further provided for discharging air sucked from the air inlet and flowing through the exhaust passage to the outside.

A plurality of the holes or the slits are formed in the multi-hole current plate along the circumferential direction, and the opening area of these holes or the slits is upstream of the downstream side of the air supplied from the air supply duct. Smaller sides are preferred.
Since the flow rate and pressure of the air supplied from the air supply duct are higher on the upstream side than on the downstream side, the opening area of the holes or slits on the upstream side is smaller than that on the downstream side in the above configuration. As a result, the resistance to the air flow increases at the opening on the upstream side, and conversely, the resistance to the flow of air decreases at the opening on the downstream side. As a result, the flow rate passing through the openings of the holes and slits can be made uniform along the circumferential direction.

An embodiment that eliminates the need for the air supply duct and the exhaust duct described above includes a centrifugal blower provided in the exhaust flow path and a filter that removes foreign matter or odors contained in the sucked air. .
With such a configuration, it is possible to generate a swirling airflow using the airflow blown out from the centrifugal blower, and to remove foreign substances such as dust and oily smoke contained in the sucked air, as well as odors. We can improve the environment.

A plurality of the holes or the slits formed in the circumferential direction are arranged concentrically in the multi-hole straightening plate, and the opening area of these holes or slits is larger on the radially outer side than on the radially inner side. Large is preferred.
Due to the centrifugal force, the flow velocity of the air supplied from the air supply duct is higher on the radially outer side than on the radially inner side. Since the opening area is increased, resistance to air flow is reduced, and pressure loss can be reduced.

According to the present invention configured as described above, local ventilation performance can be improved by equalizing the velocity distribution of the whirling airflow along the circumferential direction.

1 is a schematic diagram showing the overall configuration of a local ventilation device according to the present embodiment; FIG. The schematic diagram which shows the structure of the multi-hole straightening plate in the same embodiment, and an annular straightening plate. The schematic diagram which shows the structure of the multi-hole straightening plate in other embodiment. The schematic diagram which shows the structure of the multi-hole straightening plate in other embodiment. The schematic diagram which shows the whole structure of the local ventilation apparatus in other embodiment. The schematic diagram which shows the structure of the multi-hole straightening plate in other embodiment.

An embodiment of a local ventilator according to the present invention will be described below with reference to the drawings.

The local ventilation device 100 according to the present embodiment is provided, for example, above an electric heating cooker to locally ventilate the vicinity of the source of oily smoke. Specifically, as shown in FIG. It has an air suction port X1 facing downward and a plurality of air discharge ports X2 provided around the air suction port X1, and air is discharged obliquely downward from the plurality of air discharge ports X2. By doing so, a swirling air current is generated, thereby exhibiting a local ventilation function. However, this local ventilation device 100 is not necessarily limited to above the electric heating cooker, and may be arranged in various places.

As shown in FIG. 1, the local ventilator 100 of the present embodiment communicates with an air inlet X1, an exhaust passage L1 for discharging the air sucked from the air inlet X1, and an air outlet around the exhaust passage L1. and an air supply passage L2 that communicates with the air outlet X2 and guides air to the air outlet X2.

More specifically, the local ventilation device 100 includes an inner casing 10 having an internal space formed as an exhaust flow path L1, and an air supply flow path provided outside the inner casing 10 between the inner casing 10 and the inner casing 10. It has a supply and exhaust chamber 30 consisting of an outer casing 20 forming L2. That is, the air supply/exhaust chamber 30 has a double tubular structure with the inner casing 10 and the outer casing 20 surrounding the inner casing 10 .

The inner casing 10 has an inner peripheral surface 11 and an outer peripheral surface 12 with a circular cross section. A lower end opening 10a of the inner casing 10 is connected to a suction chamber 40 in which the air suction port X1 described above is formed. An upper end opening 10b of the inner casing 10 is connected to an exhaust duct 50 for exhausting air to the outside of the room. As a result, indoor air sucked from the air suction port X1 flows through the suction chamber 40 into the exhaust flow path L1 in the inner casing 10 and is discharged to the outside of the room via the exhaust duct 50 .

At least the inner peripheral surface 21 of the outer casing 20 has a circular cross section. An air supply flow path L2 is formed between the inner peripheral surface 21 of the outer casing 20 and the outer peripheral surface 12 of the inner casing 10 described above. In this embodiment, an air supply duct 60 is connected to the outer peripheral surface 22 of the outer casing 20 to guide air from the outside to the air supply passage L2. The air supply duct 60 is connected along the tangential direction of the inner peripheral surface 21 of the outer casing 20, so that the air guided from the air supply duct 60 to the air supply passage L2 flows through the air supply passage L2. It circulates and flows downward.

As shown in FIG. 2, the local ventilation device 100 of the present embodiment is provided upstream of the air discharge port X2 in the air supply flow path L2, and has a plurality of holes 70h (hereinafter referred to as " , and small holes 70h).

As shown in FIG. 2, the multi-hole rectifying plate 70 of the present embodiment has a large number of circular small holes 70h. Here, the small holes 70h of the same size are arranged at regular intervals along the circumferential direction. It is These small holes 70h are not formed radially inwardly of the multi-hole rectifying plate 70, but are formed only radially outwardly. are placed in

This multi-hole straightening plate 70 is provided from the inner peripheral surface 21 of the outer casing 20 to the outer peripheral surface 12 of the inner casing 10 . That is, the multi-hole rectifying plate 70 is provided so as to block the space between the inner peripheral surface 21 of the outer casing 20 and the outer peripheral surface 12 of the inner casing 10 . As a result, the air guided from the intake duct to the air supply passage L2 swirls toward the multi-hole straightening plate 70, and substantially all of the air passes through the small holes 70h. When the air passes through the small hole 70h, the inner peripheral surface of the small hole 70h functions as a rectifying surface that smoothes and rectifies the velocity component along the circumferential direction of the swirling air.

In the configuration described above, the local ventilation device 100 of the present embodiment is provided downstream of the multi-hole straightening plate 70 in the air supply flow path L2 and upstream of the air outlet X2, as shown in FIG. An annular current plate 80 is further provided.

The annular straightening plate 80 is in the shape of an annular flat plate, and has an air passage hole 80h for allowing air to pass through at the center thereof. That is, the annular current plate 80 extends from the inner peripheral surface 21 of the outer casing 20 toward the outer peripheral surface 12 of the inner casing 10, and is provided with a gap between it and the outer peripheral surface 12 of the inner casing 10. This gap is formed as the air passage hole 80h described above.

With this configuration, the air that has passed through the small holes 70h of the multi-hole straightening plate 70 described above is guided to the air passage holes 80h while swirling along the upper surface of the annular straightening plate 80, and passes through the air passage holes 80h. It is guided to the ejection port X2. The upper surface of the annular straightening plate 80 functions as a straightening surface that smoothes and straightens the downward velocity component of the swirling air.

In this embodiment, as shown in FIG. 2, a plurality of wind direction plates 90 are provided to convert the air passing through the air passage holes 80h into an obliquely downward flow and guide it to the air outlet X2. These wind direction plates 90 are arranged at regular intervals along the circumferential direction, and each direction plate 90 is inclined at a predetermined angle in the air swirling direction with respect to the vertically downward direction.

In this configuration, the inclined flow path 90L sandwiched between the adjacent wind direction plates 90 communicates the downstream side of the annular current plate 80 and the air discharge port X2, and the air flowing through the inclined flow path 90L is discharged obliquely downward from the air discharge port X2. As a result, a swirling flow is generated in the room, thereby exhibiting a local ventilation function.

According to the local ventilation system 100 configured in this manner, a plurality of small holes 70h for allowing air to pass are formed in the outer peripheral portion of the multi-hole straightening plate 70. Since it functions as a rectifying surface that smoothes and rectifies the velocity component along the direction, it is possible to equalize the velocity distribution along the circumferential direction of the swirling airflow that is discharged from the air discharge port X2. Local ventilation performance can be improved.

Further, since the annular straightening plate 80 is provided downstream of the multi-hole straightening plate 70, not only the air velocity distribution along the circumferential direction but also the downward velocity distribution can be made uniform.

Furthermore, since the air supply duct 60 is connected tangentially to the inner peripheral surface 21 of the outer casing 20, the air supplied from the air intake duct to the air supply flow path L2 can be swirled. As a result, it is possible to sufficiently ensure the air volume of the whirling airflow formed by discharging the air from the air discharge port X2, and to secure the local ventilation performance.

In addition, the present invention is not limited to the above embodiments.

For example, the multi-hole straightening plate 70 has a large number of small circular holes 70h in the above embodiment, but as shown in FIG. It may be formed.

Moreover, as shown in FIG. 4, the opening area of the holes 70h or the slits 70s formed in the multi-hole straightening plate 70 is smaller on the upstream side than on the downstream side of the air supplied from the air supply duct 60. It may be formed so as to be
With such a configuration, since the opening area of the hole 70h or the slit 70s is smaller on the upstream side than on the downstream side, the resistance to the air flow increases at the opening on the upstream side. The side openings provide less resistance to air flow. Thereby, the flow rate passing through the openings of the holes 70h or the slits 70s can be made uniform along the circumferential direction.

In addition, as the local ventilation device 100 according to the present invention, in the above-described embodiment, the air sucked from the room is discharged to the outside, but as shown in FIG. It may be returned.

Specifically, the local ventilator 100 includes a centrifugal fan Z provided in the exhaust flow path L1, and a filter F for removing foreign substances or odors contained in the sucked air.

The centrifugal blower Z sucks indoor air through the air inlet X1 and discharges the sucked air radially outward, for example, a turbo fan or a sirocco fan.

Although the filter F is arranged at or near the air suction port X1 here, it may be arranged upstream or downstream of the centrifugal blower Z. Also, multiple types of filters F may be arranged in series.

With such a configuration, a swirling airflow can be generated using the airflow blown out from the centrifugal blower Z, and the filter F removes foreign substances such as dust and oily smoke contained in the sucked air and odors. It is possible to improve the indoor environment.

Furthermore, as shown in FIG. 5, in the configuration provided with the centrifugal blower Z, the opening area of the holes 70h or the slits 70s formed in the multi-hole straightening plate 70 is larger than the radially inner side, as shown in FIG. It may be formed to be larger on the radially outer side.
With such a configuration, the flow velocity of the air supplied from the centrifugal blower Z is higher in the radially outer side than in the radially inner side due to the centrifugal force, and the radially outer side is higher than the radially inner side in the hole 70h or . Since the opening area of the slit 70s is increased, the resistance to air flow is reduced, and the pressure loss can be reduced.

In addition, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications are possible without departing from the spirit of the present invention.

100 Local ventilator X1 Air suction port X2 Air discharge port L1 Exhaust flow path L2 Air supply flow path 10 Inner casing 20 Outer casing 30 Air supply/exhaust chamber 40 Suction chamber 50 Exhaust duct 60 Air supply duct 70 Multi-hole straightening plate 70h Small hole 80 Annular straightening plate 80h Air passage hole 90 Wind direction plate 90L Inclined flow path

Claims (8)

A local ventilator comprising an air suction port that opens downward and an air discharge port that is provided around the air suction port and discharges air while swirling it obliquely downward,
an exhaust flow path that communicates with the air suction port and discharges the air sucked from the air suction port;
an air supply channel formed around the exhaust channel and communicating with the air outlet to guide air to the air outlet;
A local ventilator, comprising: a multi-hole straightening plate provided on the upstream side of the air discharge port in the air supply passage, and having a plurality of holes or slits formed in an outer peripheral portion thereof for allowing air to pass through. 2. The local ventilator according to claim 1, further comprising an annular flow straightening plate provided downstream of said multi-hole flow straightening plate and having an air passage hole formed in its central portion for allowing air to pass through. An air supply/exhaust chamber comprising an inner casing having an internal space formed as the exhaust flow path, and an outer casing provided outside the inner casing and forming the air supply flow path between the inner casing,
The multi-hole straightening plate is provided from the inner peripheral surface of the outer casing to the outer peripheral surface of the inner casing,
3. The annular current plate according to claim 2, wherein said annular current plate extends from the inner peripheral surface of said outer casing toward the outer peripheral surface of said inner casing and is provided with a gap between it and the outer peripheral surface of said inner casing. Local ventilation. 4. The air supply duct according to any one of claims 1 to 3, further comprising an air supply duct connected from the radially outer side of the outer casing forming the air supply channel to supply air to the air supply channel from the side. local ventilation. 5. The local ventilator according to claim 3, further comprising an exhaust duct connected to an upper portion of said inner casing for exhausting to the outside the air sucked from said air inlet and flowing through said exhaust passage. A plurality of the holes or the slits are formed in the multi-hole current plate along the circumferential direction, and the opening area of these holes or the slits is upstream of the downstream side of the air supplied from the air supply duct. 5. A local ventilator according to claim 4, wherein the sides are smaller. a centrifugal blower provided in the exhaust flow path;
4. The local ventilator according to any one of claims 1 to 3, further comprising a filter for removing foreign substances or odors contained in the sucked air. A plurality of the holes or the slits formed in the circumferential direction are arranged concentrically in the multi-hole straightening plate, and the opening area of these holes or slits is larger on the radially outer side than on the radially inner side. 8. The local ventilation system of claim 7, which is large.

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