JP7652525B2 - Local ventilation equipment - Google Patents

Description

The present invention relates to a local ventilation device.

In recent years, electric cooking appliances that do not use fire have become popular, and these appliances have the advantage of being easy to clean because they are made up of a flat panel top.

On the other hand, electric cooking appliances have a problem in that the upward airflow speed of the air containing the oily smoke generated from the object being heated is slower than that of gas cooking appliances, and if the oily smoke does not reach the collection range of the ventilation system above, it will spread throughout the room, causing adverse effects on the indoor environment and people. Of course, the collection range can be expanded by increasing the ventilation air volume, but in this case, other problems arise, such as increased noise and vibrations that cause discomfort to users.

Therefore, there is a local ventilation device as shown in Patent Document 1 that prevents the spread of oily smoke while maintaining the ventilation air volume.

Specifically, this local ventilation device has a number of air outlets around an air intake port facing downward, and by discharging air diagonally downward from these air outlets, a swirling air current is generated, thereby providing a local ventilation function.

In this way, the local ventilation function of a local ventilation device depends on how smoothly a swirling air current can be generated. In the above-mentioned Patent Document 1, the air flow is rectified using two annular straightening plates, and the rectified air is directed toward the air outlet.

However, with such a straightening structure consisting of two annular straightening plates, it is not possible to obtain a straightening effect on the circumferential velocity distribution of the airflow, and as a result, the circumferential velocity distribution of the swirling airflow discharged from the air outlet deteriorates. This makes the swirling flow unstable, and it is not possible to achieve sufficient local ventilation performance.

Patent No. 6546476

The present invention was made to solve all of the above problems at once, and its main objective is to improve local ventilation performance by making the velocity distribution of the swirling airflow uniform along the circumferential direction.

That is, the local ventilation device according to the present invention is provided with an air intake opening facing downward, and an air outlet provided around the air intake opening for discharging air while swirling it diagonally downward, and is characterized by having an exhaust flow path that communicates with the air intake opening and exhausts the air sucked in through the air intake opening, an air supply flow path that is formed around the exhaust flow path and communicates with the air outlet opening to guide air to the air outlet opening, and a multi-hole air straightening plate that is provided upstream of the air outlet opening in the air intake flow path and has multiple holes or slits formed on the outer periphery to allow air to pass through.

The local ventilation device configured in this way is equipped with a multi-hole straightening plate with multiple holes or slits formed on the outer periphery to allow air to pass through, so that when the air passes through these holes or slits, the velocity components along the circumferential direction can be eliminated to some extent and smoothed out. As a result, the velocity distribution along the circumferential direction of the swirling airflow generated when this air is discharged from the air outlet can be made uniform, which in turn improves local ventilation performance.

It is preferable that the air conditioner further comprises an annular straightening plate provided downstream of the multi-hole straightening plate and having an air passage hole formed in the center thereof for allowing air to pass therethrough.
With this configuration, not only the velocity distribution along the circumferential direction but also the velocity distribution in the downward direction can be made uniform by the annular straightening vane.

It is preferable that the compressor is provided with an air supply and exhaust chamber consisting of an inner casing whose internal space is formed as the exhaust flow path, and an outer casing which is provided outside the inner casing and forms the air supply flow path between the inner casing and the outer casing, and that the multi-hole baffle plate is provided from the inner surface of the outer casing to the outer circumferential surface of the inner casing, and that the annular baffle plate extends from the inner surface of the outer casing toward the outer circumferential surface of the inner casing and is provided with a gap between it and the outer circumferential surface of the inner casing.
With this configuration, the velocity component along the circumferential direction can be made uniform as the air passes through the holes or slits of the multi-hole air straightening plate, and the downward velocity component can be made uniform as the air flows along the annular air straightening plate.

It is preferable that the compressor further include an air intake duct connected from a radially outer side of the outer casing to supply air from a side to the air intake passage.
With this configuration, the air supplied to the air intake flow path can be swirled, thereby ensuring sufficient volume of the swirling airflow created by air being discharged from the air outlet, thereby ensuring local ventilation performance.

A more specific embodiment is one further comprising an exhaust duct connected to the upper part of the inner casing, which draws in air through the air intake port and discharges the air flowing through the exhaust flow path to the outside.

It is preferable that the multi-hole baffle plate has a plurality of holes or slits formed along the circumferential direction, and that the opening area of these holes or slits is smaller on the upstream side than on the downstream side of the air supplied from the air supply duct.
Since the flow rate and pressure of air supplied from the air supply duct are greater on the upstream side than on the downstream side, with the above-mentioned configuration, the opening area of the holes or slits is smaller on the upstream side than on the downstream side, so the resistance to the air flow is greater at the upstream openings and, conversely, is smaller at the downstream openings. This makes it possible to make the flow rate passing through the openings of the holes or slits uniform in the circumferential direction.

An example of an embodiment that eliminates the need for the above-mentioned intake duct and exhaust duct is one that 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 this configuration, a swirling airflow can be generated using the airflow blown out from the centrifugal blower, and foreign matter such as dust and oily smoke and odors contained in the sucked air can be removed, thereby improving the indoor environment.

The multi-hole straightening plate has a plurality of holes or slits formed in the circumferential direction and arranged concentrically, and it is preferable that the opening area of these holes or slits is larger on the radially outer side than on the radially inner side.
The flow velocity of air supplied from the air intake duct is greater radially outward than radially inward due to centrifugal force. With the above-described configuration, the opening area of the holes or slits is larger on the radially outward side than on the radially inward side, so that resistance to the air flow is smaller and pressure loss can be reduced.

The present invention, configured in this way, can improve local ventilation performance by making the velocity distribution of the swirling airflow uniform along the circumferential direction.

1 is a schematic diagram showing an overall configuration of a local ventilation device in an embodiment of the present invention. 5A and 5B are schematic diagrams showing the configurations of a multi-hole flow plate and an annular flow plate in the embodiment; FIG. 11 is a schematic diagram showing the configuration of a multi-hole flow plate in another embodiment. FIG. 11 is a schematic diagram showing the configuration of a multi-hole flow plate in another embodiment. FIG. 13 is a schematic diagram showing the overall configuration of a local ventilation device according to another embodiment. FIG. 11 is a schematic diagram showing the configuration of a multi-hole flow plate in another embodiment.

Below, one embodiment of the local ventilation device according to the present invention will be described with reference to the drawings.

The local ventilation device 100 according to this embodiment is installed, for example, above an electric cooking appliance to locally ventilate the area around the source of oily smoke. Specifically, as shown in FIG. 1, it has an air intake port X1 facing downward and multiple air outlet ports X2 installed around the air intake port X1, and is configured to discharge air diagonally downward from the multiple air outlet ports X2 to generate a swirling air current, thereby providing a local ventilation function. However, this local ventilation device 100 is not necessarily limited to being installed above an electric cooking appliance, and may be installed in various locations.

As shown in FIG. 1, the local ventilation device 100 of this embodiment has an exhaust flow path L1 that communicates with the air intake port X1 and exhausts the air sucked in from the air intake port X1, and an air supply flow path L2 that is formed around the exhaust flow path L1 and communicates with the air outlet port X2 to guide the air to the air outlet port X2.

More specifically, the local ventilation device 100 is provided with an air supply/exhaust chamber 30 consisting of an inner casing 10 whose internal space is formed as an exhaust flow path L1, and an outer casing 20 that is provided outside the inner casing 10 and forms an air supply flow path L2 between the inner casing 10 and the outer casing 20. In other words, the air supply/exhaust chamber 30 has a double-cylinder structure consisting of the inner casing 10 and the outer casing 20 that surrounds the inner casing 10.

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

At least the inner circumferential surface 21 of the outer casing 20 has a circular cross section. The space between the inner circumferential surface 21 of the outer casing 20 and the outer circumferential surface 12 of the inner casing 10 described above is formed as the air intake passage L2. In this embodiment, an air intake duct 60 that guides air from the outside to the air intake passage L2 is connected to the outer circumferential surface 22 of the outer casing 20. The air intake duct 60 is connected along the tangential direction of the inner circumferential surface 21 of the outer casing 20, so that the air guided from the air intake duct 60 to the air intake passage L2 flows downward while swirling through the air intake passage L2.

As shown in FIG. 2, the local ventilation device 100 of this embodiment is provided upstream of the air outlet X2 in the air supply flow path L2, and includes a multi-hole baffle plate 70 having a plurality of holes 70h (hereinafter also referred to as small holes 70h) formed on the outer periphery to allow air to pass through.

As shown in FIG. 2, the multi-hole straightening plate 70 of this embodiment has many circular small holes 70h formed therein, and the small holes 70h are of the same size and arranged at equal intervals along the circumferential direction. These small holes 70h are not formed on the radially inner side of the multi-hole straightening plate 70, but only on the radially outer side, and are arranged on multiple concentric circles, in other words, in multiple rings.

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. In other words, this multi-hole straightening 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 flow path L2 swirls toward the multi-hole straightening plate 70, and almost all of the air passes through the small holes 70h. Then, as the air passes through the small holes 70h, the inner peripheral surface of the small holes 70h functions as a straightening surface that smooths and straightens the speed components of the swirling air along the circumferential direction.

In the above-described configuration, the local ventilation device 100 of this embodiment further includes an annular straightening plate 80 that 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.

The annular straightening plate 80 is a flat plate having an annular shape, and an air passage hole 80h is formed in the center thereof to allow air to pass through. That is, the annular straightening 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, and this gap is formed as the air passage hole 80h described above.

With this configuration, the air that passes 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 is guided through the air passage holes 80h to the air outlet port X2. The upper surface of the annular straightening plate 80 functions as a straightening surface that smooths and straightens the downward velocity component of the swirling air.

In this embodiment, as shown in FIG. 2, multiple airflow direction plates 90 are provided to redirect the air that has passed through the air passage holes 80h to a diagonally downward flow and direct it to the air outlet X2. These airflow direction plates 90 are arranged at equal intervals along the circumferential direction, and each airflow direction plate 90 is inclined at a predetermined angle in the swirling direction of the air relative to the vertical downward direction.

In this configuration, the inclined flow path 90L sandwiched between the adjacent air direction vanes 90 connects the downstream side of the annular straightening vane 80 and the air outlet X2, and the air that flows through this inclined flow path 90L is discharged diagonally downward from the air outlet X2. As a result, a swirling flow is generated in the room, which provides local ventilation.

With the local ventilation device 100 configured in this manner, multiple small holes 70h are formed on the outer periphery of the multi-hole straightening plate 70 to allow air to pass through, and the inner periphery of these small holes 70h functions as a straightening surface that smooths and straightens the circumferential velocity components of the swirling air, so that the speed distribution along the circumferential direction of the swirling airflow produced when this air is discharged from the air outlet X2 can be made uniform, thereby improving local ventilation performance.

In addition, an annular straightening plate 80 is provided downstream of the multi-hole straightening plate 70, which makes it possible to equalize not only the circumferential velocity distribution of the air, but also the downward velocity distribution.

Furthermore, since the air intake duct 60 is connected tangentially to the inner peripheral surface 21 of the outer casing 20, the air supplied from this air intake duct to the air intake flow path L2 can be swirled. This ensures a sufficient volume of the swirling airflow created by air being discharged from the air outlet X2, ensuring local ventilation performance.

The present invention is not limited to the above embodiment.

For example, in the above embodiment, the multi-hole straightening plate 70 has many small circular holes 70h formed therein, but as shown in FIG. 3, it may have many slits 70s formed, for example at equal intervals, along the circumferential direction.

In addition, the holes 70h or slits 70s formed in the multi-hole straightening plate 70 may be formed so that their opening area is smaller on the upstream side than on the downstream side of the air supplied from the air supply duct 60, as shown in Figure 4.
In this configuration, the opening area of the holes 70h or slits 70s is smaller on the upstream side than on the downstream side, so that the resistance to the air flow is greater at the upstream opening and, conversely, is smaller at the downstream opening, which makes it possible to make the flow rate passing through the openings of the holes 70h or slits 70s uniform in the circumferential direction.

In addition, in the above embodiment, the local ventilation device 100 according to the present invention is configured to exhaust air drawn in from inside the room to the outside, but as shown in FIG. 5, it may also be configured to return air drawn in from inside the room back into the room.

Specifically, this local ventilation device 100 is equipped with a centrifugal blower Z installed in the exhaust flow path L1 and a filter F that removes foreign matter or odors contained in the sucked air.

The centrifugal blower Z draws in indoor air through the air intake port X1 and expels the air, for example, radially outward, and is, for example, a turbo fan or a centrifugal fan.

Here, the filter F is placed at or near the air intake X1, but it may be placed upstream or downstream of the centrifugal blower Z. Also, multiple types of filters F may be placed in series.

With this configuration, a swirling air current can be generated using the airflow blown out from the centrifugal blower Z, and foreign matter such as dust and oily smoke, as well as odors, contained in the sucked air can be removed by the filter F, improving the indoor environment.

Furthermore, in a configuration including a centrifugal blower Z as shown in FIG. 5, the holes 70h or slits 70s formed in the multi-hole straightening plate 70 may be formed so that their opening area is larger on the radially outer side than on the radially inner side as shown in FIG. 6.
With this configuration, the flow velocity of the air supplied from the centrifugal blower Z is greater radially outward than radially inward due to centrifugal force, and since the opening area of the holes 70h or slits 70s is larger radially outward than radially inward, resistance to the air flow is reduced, thereby reducing pressure loss.

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

REFERENCE SIGNS LIST 100: Local ventilation device X1: Air intake port X2: Air discharge port L1: Exhaust flow path L2: Air supply flow path 10: Inner casing 20: Outer casing 30: Air supply and exhaust chamber 40: Intake 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: Air direction plate 90L: Inclined flow path

Claims (5)

A local ventilation device comprising an air intake opening facing downward and an air exhaust opening provided around the air intake opening for exhausting air while swirling the air diagonally downward,
an exhaust flow path that communicates with the air intake port and exhausts air sucked through the air intake port;
an air supply passage formed around the exhaust passage and communicating with the air outlet to guide air to the air outlet;
a multi-hole air straightening plate provided on the upstream side of the air discharge port in the air supply flow path and having a plurality of holes or slits formed on an outer periphery thereof for allowing air to pass therethrough;
an air intake duct connected from a radially outer side of an outer casing that forms the air intake passage and supplying air from a side to the air intake passage,
A local ventilation device characterized in that a plurality of holes or slits are formed in the multi-hole straightening plate along the circumferential direction, and the opening area of these holes or slits is smaller on the upstream side than on the downstream side of the air supplied from the air supply duct . The local ventilation device according to claim 1, further comprising an annular straightening plate provided downstream of the multi-hole straightening plate and having an air passage hole formed in the center thereof for allowing air to pass through. an intake and exhaust chamber including 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 intake flow path between the inner casing and the outer casing;
The multi-hole flow plate is provided from the inner peripheral surface of the outer casing to the outer peripheral surface of the inner casing,
3. The local ventilation device according to claim 2, wherein the annular baffle vane extends from the inner peripheral surface of the outer casing toward the outer peripheral surface of the inner casing with a gap therebetween. The local ventilation device according to claim 3 , further comprising an exhaust duct connected to an upper portion of the inner casing for drawing in air from the air inlet and discharging air flowing through the exhaust passage to the outside. A local ventilation device comprising an air intake opening facing downward and an air exhaust opening provided around the air intake opening for exhausting air while swirling the air diagonally downward,
an exhaust flow path that communicates with the air intake port and exhausts air sucked through the air intake port;
an air supply passage formed around the exhaust passage and communicating with the air outlet to guide air to the air outlet;
a multi-hole air straightening plate provided on the upstream side of the air discharge port in the air supply flow path and having a plurality of holes or slits formed on an outer periphery thereof for allowing air to pass therethrough;
A centrifugal blower provided in the exhaust flow path;
A filter for removing foreign matter or odor contained in the sucked air,
A local ventilation device in which the holes or slits are formed in the circumferential direction of the multi-hole straightening plate and arranged concentrically, and the opening area of these holes or slits is larger on the radially outer side than on the radially inner side.