JP2022030373A - Ventilation system - Google Patents

Abstract

To provide a ventilation system capable of obtaining sufficient ventilation action even in a space with no wall around a device.SOLUTION: A ventilation system 1 comprises: a plate member 2 provided so as to extend laterally; a supply and exhaust device 3 including an air supply opening 6 provided above the plate member 2, annularly provided on a lower surface exposed from the plate member 2, and supplying air into a room R diagonally downward in the same circumferential direction, and an air outlet opening 7 provided inside in a radial direction of the air supply opening 6 and discharging air to the outside of the room; and a cylindrical member 4 suspended from the plate member 2 and provided outside in the radial direction of the air supply opening 6 so as to annually surround a space Sr below the plate member 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a ventilation system.

A local ventilation system is used to ventilate (exhaust) odors, heat and contaminated air caused by heating work, cigarette smoke, dust, oil mist, etc. that are locally generated in the room.

For example, in Patent Document 1, a large number of air introduced into a space formed in a substantially conical blower chamber are arranged in a swirling flow generating stator at a predetermined interval in the circumferential direction in a swirling direction. A tornado-type airflow control device having a configuration in which a large vector is applied to blow out from an air outlet as a spiral swirling flow (swirl swirling flow) and an intake hood is provided inside the air blowing chamber is disclosed. In such a configuration, the spiral swirling flow blown into the room forms an air curtain flow, and a vortex flow (intake swirling vortex flow) that rises in a tornado shape by the suction force sucked in the exhaust direction by the intake hood inside the air curtain flow. ) Is formed, and the ventilation action of the local area is realized.
The configuration as disclosed in Patent Document 1 is premised on use in a small room. That is, in the configuration of Patent Document 1, the spiral swirling flow blown into the room by the wall of the building provided to form the indoor space does not diffuse to the surroundings and maintains the swirling vortex flow by 2 to 3 m. It flows downward to some extent. On the other hand, when such a device is to be installed in a large space such as a factory, the spiral swirling flow blown into the room moves downward by about 40 to 50 cm to the outer peripheral side. It will spread. Building a wall around the device to allow the spiral swirling flow to flow further down is impractical, especially in factories, as it interferes with work. Therefore, a tornado-shaped vortex flow may not be sufficiently generated inside the swirling flow, and the intended ventilation action may not be obtained.

Japanese Unexamined Patent Publication No. 2001-82778

An object of the present invention is to provide a ventilation system capable of obtaining a sufficient ventilation action even in a space having no surrounding wall.

The present invention employs the following means in order to solve the above problems.
That is, the ventilation system of the present invention is provided in the same circumferential direction as the plate member extending laterally and the plate member provided above the plate member and annularly provided on the lower surface exposed from the plate member. An air supply port that supplies air to the room diagonally downward, and an air supply / exhaust device that is provided inside the air supply port in the radial direction and has an exhaust port that discharges air to the outside of the room. It is provided with a tubular member suspended from the plate member and provided radially outside the air supply port so as to surround the space below the plate member in an annular shape.
According to such a configuration, the air supplied into the room from the annular air supply port provided by being exposed from the plate member extending in the lateral direction is directed diagonally downward in the same circumferential direction. Flows. The air flowing diagonally downward spreads outward in the radial direction, hits the inner peripheral surface of the tubular member provided on the outer side in the radial direction from the air supply port, and then hits the inside of the tubular member. It flows along the peripheral surface. As a result, a swirling flow is generated in which the air supply port swirls downward from the air supply port.
In this way, the air blown out from the air supply port hits the inner peripheral surface of the tubular member and becomes a swirling flow, so that diffusion to the outside in the radial direction is restricted. After that, the swirling flow flows downward while swirling along the inner peripheral surface of the tubular member, and further downwards from the lower end of the tubular member while maintaining the swirling state.
Inside the radial inside of the swirling flow thus generated, sucking air through the exhaust port creates a negative pressure in the space below the discharge port, creating a continuous tornado-shaped vortex flow from the bottom to the top exhaust port. Is generated. Air is carried from the bottom to the top by this vortex and is discharged to the outside through the exhaust port.
This makes it possible to obtain a sufficient ventilation effect even in a space without a wall around it.

In one aspect of the present invention, the ventilation system of the present invention is provided inside the air supply port in the radial direction so as to surround the exhaust port and extend downward from the exhaust port. It is equipped with a cylinder.
According to such a configuration, a hollow cylinder body is formed even when the continuous tornado-shaped vortex flow generated from the lower side to the upper side cannot reach the vicinity of the plate member, which is generated inside the swirling flow in the radial direction. Captures the upper end of the tornado-shaped vortex and expels air through the hollow cylinder to the exhaust port. As a result, air can be discharged more efficiently inside the swirling flow in the radial direction.

In one aspect of the present invention, the ventilation system of the present invention has a head cone shape in which the tubular body gradually expands in diameter from the upper side to the lower side.
According to such a configuration, since the lower end of the cylinder is expanded in diameter, the exhaust port is passed through the hollow cylinder inside the radial direction of the swirling flow flowing downward while swirling from the lower end of the tubular member. The vortex air discharged to the air can be recovered more efficiently. Further, the cross-sectional area of the gap between the inner peripheral surface of the tubular member and the outer peripheral surface of the tubular body gradually decreases from the upper side to the lower side. As a result, the flow velocity of the swirling flow flowing downward while swirling inside the cylindrical member increases, and the momentum of the swirling flow flowing downward while swirling from the lower end of the tubular member becomes stronger. Therefore, the effect that a sufficient ventilation action can be obtained even in a space without a wall around it can be made more remarkable.

In one aspect of the present invention, the ventilation system of the present invention has a cylindrical body.
According to such a configuration, the tubular body can be easily manufactured.

In one aspect of the present invention, in the ventilation system of the present invention, the cylindrical body has a cylindrical first tubular portion and the lower end of the first tubular portion, and the diameter dimension gradually increases from upper to lower. It is provided with a second tubular portion formed so as to have a conical shape.
According to such a configuration, since the lower end of the second cylindrical portion having a conical shape is expanded in diameter, the inside of the radial direction of the swirling flow flowing downward while swirling downward from the lower end of the tubular member. The vortex air discharged to the exhaust port through the hollow cylinder can be recovered more efficiently. Further, the cross-sectional area of the gap between the inner peripheral surface of the tubular member and the outer peripheral surface of the tubular body gradually decreases from the upper side to the lower side in the second cylindrical portion having a conical shape. As a result, the flow velocity of the swirling flow flowing downward while swirling inside the cylindrical member increases, and the momentum of the swirling flow flowing downward while swirling from the lower end of the tubular member becomes stronger. Therefore, the effect that a sufficient ventilation action can be obtained even in a space without a wall around it can be made more remarkable.

In one aspect of the present invention, the ventilation system of the present invention is formed so that the height of the cylinder is at least half the height of the tubular member.
According to such a configuration, the vortex air can be recovered more efficiently and the flow velocity of the swirl flow can be further increased. As a result, it is possible to more reliably obtain the effect that a sufficient ventilation action can be obtained even in a space having no surrounding wall.

In one aspect of the present invention, in the ventilation system of the present invention, the height of the tubular member is 500 mm or more and 650 mm or less. According to such a configuration, the formed swirling flow reaches further downward. Will be. As a result, it is possible to more reliably obtain the effect that a sufficient ventilation action can be obtained even in a space having no surrounding wall.

According to the present invention, it is possible to obtain a sufficient ventilation action even in a space having no surrounding wall.

It is sectional drawing which shows the structure of the ventilation system which concerns on embodiment of this invention. FIG. 1 is a partial cross-sectional view taken along the line II of the ventilation system of FIG. It is an enlarged sectional view of the ventilation system of FIG. It is a figure which shows the example of the case where the ventilation system of FIG. 1 is relocated. It is sectional drawing which shows the structure of the 1st modification of the ventilation system which concerns on embodiment of this invention. It is sectional drawing which shows the structure of the 2nd modification of the ventilation system which concerns on embodiment of this invention. It is a figure which shows the verification result in the Example of this invention.

Hereinafter, embodiments for implementing the ventilation system according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a cross-sectional view showing the configuration of the ventilation system according to the embodiment of the present invention. FIG. 2 is a partial cross-sectional view taken along the line II of the ventilation system of FIG. FIG. 3 is an enlarged cross-sectional view of the ventilation system of FIG.

As shown in FIGS. 1 to 3, the ventilation system 1 includes a plate member 2, an air supply / exhaust device 3, a tubular member 4, and a tubular body 5.
The plate member 2 is provided so as to extend in the lateral direction. In particular, in the present embodiment, the plate member 2 is provided horizontally. In the present embodiment, the plate member 2 is a steel plate suspended and fixed from a ceiling slab (not shown). In the present embodiment, the plate member 2 is formed in a circular shape so as to have a contour shape substantially equivalent to that of the tubular member 4 described later.
The air supply / exhaust device 3 is arranged above the plate member 2. The air supply / exhaust device 3 is provided so that the lower surface is exposed from the opening 2a formed in the plate member 2. The air supply / exhaust device 3 includes a casing 31, an exhaust pipe 32 provided in the casing 31, an upper partition plate 33, a lower tubular body 34, a lower partition plate 35, and a plurality of guide blades 36. is doing.

As shown in FIG. 3, the casing 31 has a cylindrical shape extending in the vertical direction Dv. The upper end 31t of the casing 31 is closed. The lower end 31b of the casing 31 is open downward.
The exhaust pipe 32 has a cylindrical shape extending in the vertical direction Dv and has a diameter smaller than that of the casing 31. The exhaust pipe 32 is arranged concentrically with the casing 31. The exhaust pipe 32 is provided so as to penetrate the upper partition plate 33 and the lower partition plate 35, which will be described in detail later, in the vertical direction Dv. The exhaust pipe 32 has a diameter-expanded portion 32a on the lower side of the lower partition plate 35. The diameter-expanded portion 32a is larger than the intermediate portion 32b above the lower partition plate 35 in the exhaust pipe 32. The enlarged diameter portion 32a opens downward on the lower surface of the air supply / exhaust device 3 to form an exhaust port 7 for discharging air from the room R to the outside. The exhaust pipe 32 has a connecting pipe portion 32c that is above the upper partition plate 33, is bent in the radial direction Dr orthogonal to the vertical Dv, and extends outward in the radial direction Dr. The connection pipe portion 32c penetrates the casing 31, projects outward from the casing 31 in the radial direction, and is connected to the external exhaust duct 102. The exhaust pipe 32 sucks the air in the room R from the exhaust port 7 by a fan (not shown) or the like provided in the exhaust duct 102.

The upper partition plate 33 is provided at the upper part in the casing 31. The upper partition plate 33 is provided along a horizontal plane orthogonal to the vertical direction Dv, and partitions the inside of the casing 31 vertically.
The lower cylindrical body 34 is provided at the lower part in the casing 31. The upper ends of the lower tubular body 34 are arranged below the upper partition plate 33 at predetermined intervals in the vertical direction Dv. The lower cylindrical body 34 has a smaller diameter than the casing 31, and has a larger diameter than the enlarged diameter portion 32a of the exhaust pipe 32. The lower cylindrical body 34 is provided concentrically with the casing 31. As a result, an annular flow path 37 that is annular and continuous in the vertical direction Dv is formed between the casing 31 and the lower tubular body 34. The annular flow path 37 opens downward on the lower surface of the air supply / exhaust device 3 to form an annular air supply port 6 for supplying air to the room R. The annular flow path 37 opens upward between the upper end of the lower tubular body 34 and the casing 31.
The lower partition plate 35 is provided in parallel with the upper partition plate 33. The lower partition plate 35 closes the gap between the upper end of the lower tubular body 34 and the outer peripheral surface of the exhaust pipe 32.

Between the upper partition plate 33 and the lower partition plate 35, between the inner peripheral surface of the casing 31 and the outer peripheral surface of the intermediate portion 32b of the exhaust pipe 32, the chamber chamber 38 having an annular cross section when viewed from the vertical Dv. Is formed. An air supply pipe 39 is provided on the outer peripheral surface of the casing 31. As shown in FIG. 2, the air supply pipe 39 extends in the tangential direction of the annular chamber chamber 38, and one end thereof penetrates the casing 31 and communicates with the chamber chamber 38. An external air supply duct 101 is connected to the other end of the air supply pipe 39. Air is supplied from the air supply duct 101 to the chamber chamber 38 through the air supply pipe 39 by an air supply means such as a fan (not shown).

The plurality of guide blades 36 are provided in the annular flow path 37 between the inner peripheral surface of the casing 31 and the outer peripheral surface of the lower tubular body 34. The plurality of guide blades 36 are provided at intervals in the circumferential direction Dc around the central axis of the casing 31. As shown in FIG. 3, each guide blade 36 is provided so as to be inclined from one side of the circumferential direction Dc to the other side with respect to the vertical direction Dv from the upper end 36a to the lower end 36b. Each guide blade 36 is provided so as to be inclined at a predetermined inclination angle θ with respect to the radial direction Dr (horizontal direction) orthogonal to the vertical direction Dv. The inclination angle θ of each guide blade 36 is preferably 10 to 30 °, for example. In reality, it is desirable that the inclination angle θ is shallower, but if it is too shallow, manufacturing becomes difficult. Therefore, in reality, the inclination angle θ is more preferably 15 to 20 °.

The tubular member 4 is suspended from the plate member 2. The tubular member 4 has a cylindrical shape extending in the vertical direction Dv. The upper end of the tubular member 4 is closed by the plate member 2. The tubular member 4 has a larger diameter than the casing 31 of the air supply / exhaust device 3. As a result, the tubular member 4 is provided outside the radial direction Dr with respect to the air supply port 6. The tubular member 4 is provided so as to surround the upper portion of the space Sr in the room R below the plate member 2, which is located in the vicinity of the air supply / exhaust device 3, in an annular shape. For the tubular member 4, for example, when the diameter of the tubular member 4 is 1500 mm and the diameter of the air supply port 6 is about 600 mm, the height H1 in the vertical direction Dv is preferably 500 mm or more and 650 mm or less.

The tubular body 5 is provided on the lower side of the plate member 2. The upper end of the cylinder 5 is fixed to the lower surface of the air supply / exhaust device 3. The tubular body 5 has a hollow tubular shape and is provided so as to extend downward from the lower surface (lower end) of the air supply / exhaust device 3. The upper end 5t of the cylinder 5 is provided inside the radial Dr with respect to the air supply port 6. The upper end 5t of the tubular body 5 is provided outside the radial direction Dr with respect to the exhaust port 7. As a result, the tubular body 5 is provided so as to surround the exhaust port 7. It is preferable that the height H2 of the tubular member 5 in the vertical direction Dv is at least half the height H1 of the tubular member 4 and at least the height H1 of the tubular member 4.
In the present embodiment, the tubular body 5 has a conical shape in which the diameter gradually increases from the upper side to the lower side.

In such a ventilation system 1, the air supply / exhaust device 3 supplies air to the chamber chamber 38 in the casing 31 through the air supply pipe 39. Then, the air supplied from the air supply pipe 39 flows into the annular flow path 37 below the annular chamber chamber 38 while swirling in the circumferential direction Dc along the inner peripheral surface of the chamber chamber 38. The air flowing into the annular flow path 37 passes between the plurality of guide blades 36 while swirling in the circumferential direction Dc, and flows out from the annular air supply port 6 to the lower chamber R. In this way, the air supply port 6 supplies air diagonally downward in the same circumferential direction Dc. Here, the flow of air flowing out from the air supply port 6 to the room R is at an angle of 10 to 30 ° with respect to the horizontal direction, more preferably 15 to 20, depending on the inclination angle θ of the plurality of guide blades 36. It is discharged at an angle of °.
In this way, the air supplied to the room R from the annular air supply port 6 exposed on the plate member 2 flows diagonally downward in the same circumferential direction. The air flowing diagonally downward spreads to the outside of the radial Dr, and after hitting the inner peripheral surface of the tubular member 4 provided on the outside of the radial Dr from the air supply port 6, the cylinder It flows along the inner peripheral surface of the shaped member 4. As a result, a swirling flow F1 that flows while swirling downward from the air supply port 6 is generated.
In this way, the air blown out from the air supply port 6 to the outside of the radial Dr abuts on the inner peripheral surface of the tubular member 4 and becomes a swirling flow F1, so that diffusion of the radial Dr to the outside is restricted. To. After that, the swirling flow F1 flows downward while swirling along the inner peripheral surface of the tubular member 4, and further downward from the lower end of the tubular member 4 toward the floor surface 9 (see FIG. 1). , It flows while maintaining the turning state.
Inside the radial Dr of the swirling flow F1 generated in this way, a negative pressure is generated in the space Sr below the exhaust port 7 by sucking air at the exhaust port 7, and the air is directed from the lower side toward the upper exhaust port 7. A continuous tornado-shaped vortex flow F2 is generated. The air in the space Sr below the exhaust port 7 is carried from the lower side to the upper side by the vortex flow F2, and is discharged to the outside through the exhaust port 7.

According to the ventilation system 1 as described above, the plate member 2 extending laterally and the plate member 2 are provided above the plate member 2 and are provided in an annular shape on the lower surface exposed from the plate member 2 to be the same. It is provided with an air supply port 6 for supplying air to the room R diagonally downward in the circumferential direction Dc, and an exhaust port 7 provided inside the radial direction Dr from the air supply port 6 and discharging the air to the outside of the room. A tubular member suspended from the air supply / exhaust device 3 and the plate member 2 and provided outside the air supply port 6 in the radial direction so as to surround the space Sr below the plate member 2 in an annular shape. 4 and.
According to such a configuration, due to the above-mentioned action, it is possible to obtain a sufficient ventilation action even in a space Sr having no surrounding wall.

Further, the ventilation system 1 includes a hollow cylinder 5 provided inside the air supply port 6 in the radial direction so as to surround the exhaust port 7 and extend downward from the exhaust port 7. There is.
According to such a configuration, even when the tornado-shaped vortex flow F2 generated inside the radial direction Dr of the swirl flow F1 and continuous from the lower side to the upper side cannot reach the vicinity of the plate member 2. The upper end of the tornado-shaped vortex flow F2 is captured by the hollow cylinder 5, and air can be guided to the exhaust port 7 through the hollow cylinder 5. As a result, air can be discharged more efficiently by the vortex flow F2 inside the radial direction Dr of the swirl flow F1.

Further, the tubular body 5 has a vertical conical shape in which the diameter dimension gradually increases from the upper side to the lower side.
According to such a configuration, since the lower end of the cone-shaped cylinder 5 has an enlarged diameter, the air of the vortex F2 discharged to the exhaust port 7 through the hollow cylinder 5 is recovered more efficiently. be able to. Further, the cross-sectional area of the gap between the inner peripheral surface of the tubular member 4 and the outer peripheral surface of the tubular body 5 gradually decreases from the upper side to the lower side. As a result, the flow velocity of the swirling flow F1 swirling downward inside the tubular member 4 increases, and the momentum of the swirling flow F1 swirling downward from the lower end of the tubular member 4 becomes stronger. Become. Therefore, the effect that a sufficient ventilation effect can be obtained even in a space Sr having no surrounding wall can be made more remarkable.

Further, the cylindrical body 5 is formed so that the height H2 is at least half the height H1 of the tubular member 4.
According to such a configuration, the air of the vortex flow F2 can be recovered more efficiently, and the flow velocity of the swirl flow F1 can be further increased. As a result, it is possible to more reliably obtain the effect that a sufficient ventilation action can be obtained even in a space Sr having no surrounding wall.

Further, the height H1 of the tubular member 4 is 500 mm or more and 650 mm or less.
According to such a configuration, the formed swirling flow F1 reaches further downward. As a result, it is possible to more reliably obtain the effect that a sufficient ventilation action can be obtained even in a space Sr having no surrounding wall.

Further, in the present embodiment, in the ventilation system 1, the plate member 2, the air supply / exhaust device 3, the tubular member 4, and the tubular body 5 are connected to each other and formed as one unit by these. There is. By unitizing the ventilation system 1 including the plate member 2 in this way, as shown in FIG. 4, the ventilation system 1 is removed from the air supply duct 101 and the exhaust duct 102 in a factory or the like, and another If it is connected to the air supply duct 101 or the exhaust duct 102, the ventilation system 1 can be easily relocated without remodeling existing equipment such as a ceiling panel.

(First modification of the embodiment)
The ventilation system of the present invention is not limited to the above-described embodiment described with reference to the drawings, and various modifications can be considered within the technical scope thereof.
For example, in the above embodiment, the tubular body 5 has a truncated cone shape, but the present invention is not limited to this.
As shown in FIG. 5, the tubular body 5B may have a cylindrical shape having a constant diameter dimension in the vertical direction Dv.
According to such a configuration, the tubular body 5B can be easily manufactured.

(Second modification of the embodiment)
Further, as shown in FIG. 6, the tubular body 5C has a cylindrical first tubular portion 52 and a head cone shape whose diameter gradually increases from upper to lower at the lower ends of the first tubular portion 52. A second cylinder portion 53 formed so as to be provided may be provided.
According to such a configuration, since the lower end of the second cylindrical portion 53 having a conical shape is expanded in diameter, the radial Dr of the swirling flow F1 flowing while swirling downward from the lower end of the tubular member 4. Inside, the air of the vortex F2 discharged to the exhaust port 7 through the hollow cylinder 5 can be recovered more efficiently. Further, the cross-sectional area of the gap between the tubular member 4 and the tubular body 5 gradually decreases from the upper side to the lower side in the second cylindrical portion 53 having a cone-shaped head. As a result, the flow velocity of the swirling flow F1 swirling downward inside the tubular member 4 increases, and the momentum of the swirling flow F1 swirling downward from the lower end of the tubular member 4 becomes stronger. Become. As a result, the effect that a sufficient ventilation action can be obtained even in a space Sr having no surrounding wall can be made more remarkable.

In addition to this, as long as it does not deviate from the gist of the present invention, it is possible to select the configuration described in the above embodiment or change it to another configuration as appropriate.

Next, the ventilation system 1 provided with the tubular member 4 and the tubular body 5 as shown in the above embodiment was verified, and the results are shown.

First, in the configuration as shown in the above embodiment, there are cases where both air supply from the air supply port 6 and exhaust from the exhaust port 7 are performed, and cases where air is not supplied from the air supply port 6 and the exhaust port is not supplied. A comparison was made with the case where only the exhaust from No. 7 was performed (the supply air flow rate was 0 m ³ / h). When supplying air from the air supply port 6, the supply air flow rate was set to 1100 m ³ / h and 1300 m ³ / h. Further, the height H1 of the tubular member 4 is set to 500 mm.
Under each condition, mist-like oil smoke was generated as dust on the floor surface 9 vertically below the exhaust port 7, and the amount of oil smoke collected through the exhaust port 7 was measured. The dust concentration (mg / m ³ ) was calculated from the ratio of the amount of collected oil smoke (mg / h) to the exhaust air volume (m ³ / h).

The results are shown in FIG.
As shown in FIG. 7, the air supply from the air supply port 6 and the exhaust from the exhaust port 7 are compared with the case where the air is not supplied from the air supply port 6 and only the exhaust from the exhaust port 7 is performed. When both were carried out, the collection rate of dust (oil smoke) was improved regardless of the supply air flow rate. Further, when the air was not supplied from the air supply port 6 but only was exhausted from the exhaust port 7, no clear vortex flow F2 was observed, whereas the air was supplied from the air supply port 6. It was visually confirmed that a tornado-shaped vortex flow F2 was generated regardless of the supply air flow rate when both the exhaust and the exhaust from the exhaust port 7 were performed. That is, by generating a tornado-shaped vortex flow F2, it is possible to more reliably collect dust (oil smoke).

筒状部材４（フード）は、径寸法（直径）１５００ｍｍとし、高さＨ１を３００ｍｍ、５００ｍｍ、６００ｍｍ、６５０ｍｍの４通りとした。
筒体５（ベルマウス）は、截頭円錐台形状とし、上端５ｔの直径Ｄ１を３００ｍｍ、下端５ｂの径寸法（直径）Ｄ２（図３参照）は、６００ｍｍ、８００ｍｍ、１０００ｍｍの３通り、高さＨ２は１５０ｍｍ、３００ｍｍ、５００ｍｍとした。また、比較のため、筒体５を備えない場合についても検討した（表１の条件Ｎｏ１２、１３）。 Next, the conditions of each part of the ventilation system 1 were made different and verified, and the verification results are shown below.
(Verification conditions)
The verification conditions were as shown in Table 1.

The cylindrical member 4 (hood) has a diameter dimension (diameter) of 1500 mm, and the height H1 is 300 mm, 500 mm, 600 mm, and 650 mm.
The tubular body 5 (bell mouth) has a truncated cone shape, and the diameter D1 of the upper end 5t is 300 mm, and the diameter dimension (diameter) D2 of the lower end 5b (see FIG. 3) is 600 mm, 800 mm, and 1000 mm. The diameter of H2 was 150 mm, 300 mm, and 500 mm. In addition, for comparison, the case where the tubular body 5 is not provided was also examined (conditions Nos. 12 and 13 in Table 1).

In the air supply / exhaust device 3, the diameter dimension of the casing 31 is 600 mm, and the inclination angle θ of the guide blade 36 is 15 °. The amount of air supplied from the air supply port 6 was 800 m ³ / h, 900 m ³ / h, 1000 m ³ / h, 1100 m ³ / h, 1200 m ³ / h, and 1300 m ³ / h. The exhaust air volume from the exhaust port 7 was 900 m ³ / h.
The height Ht of the plate member 2 (see FIG. 1) was 2100 mm, 2200 mm, 2300 mm, and 2400 mm.

Verification condition No. that combines these conditions. 1 to No. With respect to 51, mist-like oil smoke is generated as dust on the floor surface vertically below the exhaust port 7, and the generation status of the tornado-shaped vortex flow F2 is visually confirmed, and “◎”, “〇”, “△”. It was evaluated on a three-point scale. The higher the evaluation is, the more prominently the vortex F2 is generated.
The results are shown in Table 1.

As shown in Table 1, for example, the verification condition No. 1 in which only the diameter D2 of the tubular body 5 is different. From the comparison of 26, 30, and 39, the larger the diameter D2 of the tubular body 5, the more remarkable the generation of the vortex F2.

Further, for example, the verification condition No. 1 in which only the height H1 of the tubular member 4 is different. From the comparison of 17, 23, 31, and 36, when the height H1 of the tubular member 4 is 500 mm or more, the generation of the vortex F2 is remarkable.

Further, for example, the verification condition No. 1 in which only the height H2 of the tubular body 5 is different. From the comparison of 10, 23, and 28, when the height H2 of the cylindrical body 5 is set to half (1/2) or more of the height H1 of the tubular member 4, the generation of the vortex F2 becomes remarkable. There is.

1 Ventilation system 53 2nd cylinder part 2 Plate member Dc Circumferential direction 3 Air supply / exhaust device Dr Radial direction 4 Cylindrical member H1 Cylindrical member height 5, 5B, 5C Cylindrical body H2 Cylindrical body height 6 Air supply port R Indoor 7 Exhaust port Sr Space 52 1st cylinder

Claims (7)

Plate members that extend in the horizontal direction and
From the air supply port provided above the plate member and annularly provided on the lower surface exposed from the plate member to supply air diagonally downward in the same circumferential direction into the room, and from the air supply port. An air supply / exhaust device that is installed inside in the radial direction and has an exhaust port that exhausts air to the outside.
It is provided with a tubular member suspended from the plate member and provided radially outside the air supply port so as to surround the space below the plate member in an annular shape.
Ventilation system. The ventilation according to claim 1, wherein a hollow cylinder provided so as to surround the exhaust port and extend downward from the exhaust port is provided inside the air supply port in the radial direction. system. The ventilation system according to claim 2, wherein the cylinder has a conical shape in which the diameter gradually increases from the upper side to the lower side. The ventilation system according to claim 2, wherein the cylinder has a cylindrical shape. The cylinder has a cylindrical first cylinder and a second cylinder formed at the lower end of the first cylinder so as to have a rectangular cone shape in which the diameter gradually increases from the upper side to the lower side. The ventilation system according to claim 2, further comprising a unit. The ventilation system according to any one of claims 2 to 5, wherein the tubular body is formed so that the height is at least half the height of the tubular member. The ventilation system according to any one of claims 1 to 6, wherein the height of the tubular member is 500 mm or more and 650 mm or less.

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