JP2023119553A - Local exhaust table and local exhaust system of indoor space - Google Patents

Abstract

To provide a table which locally exhausts exhaled air of humans, and to provide a local exhaust system of an indoor space which locally suctions exhaled air of humans to discharge the exhaled air to the outside of a room without circulating the exhaled air.SOLUTION: A local exhaust table includes: a table body: a box body which is disposed adjacent to a back surface of the table body; and a partition provided on an upper surface of the box body. The box body includes: a suction port for suctioning exhaled air of users; an exhaust port which exhausts the exhaled air suctioned from the suction port; and a fan for exhausting the exhaled air suctioned from the suction port to the outside of the box body through the exhaust port. The local exhaust table is used to achieve the above object.SELECTED DRAWING: Figure 1

Description

The present invention relates to a local exhaust table and a local exhaust system for an indoor space provided with the local exhaust table.

The onslaught of COVID-19 has created a need for traditional classroom learning or workplace work to better combat the indoor retention, spread and transmission of coronavirus. However, the current situation is that only measures such as maintaining social distance, opening windows regularly, or using normal existing general ventilation for ventilation are taken as the main measures. .

Many partitions and ventilation devices have been invented and devised as countermeasures against the retention, spread and propagation of coronavirus. However, in order to suppress the spread and propagation of viruses contained in human coughs and exhaled breath, environmental design has not been sufficiently done with consideration given to the air flow in the indoor environment. Therefore, the conventional method exhausts harmful substances such as viruses while diffusing them, which is insufficient as a countermeasure against infection.

Here, various techniques have been disclosed so far as techniques for air purification, deodorization, sterilization, and the like. For example, it is a ventilation system that relies on suction force to exhaust soldering smoke so as not to inhale it. A device has been disclosed in which holes are arranged for use (see Patent Document 1). This invention was created as a response to the lead poisoning prevention regulations, and is intended to improve the working environment for workers outside the hood by collecting the gas generated in the hood in the hood. Therefore, no consideration is given to human exhalation.

In addition, a table is provided on the upper surface, a suction port is provided in the center or near the center of the table, a dust collection part is provided downstream of the suction port, and a photocatalyst filter and a germicidal lamp are provided for dust collection, sterilization, and deodorization functions. A table-type air purifier equipped with such a device is disclosed (see Patent Document 2). In the present invention, the air sucked from the suction port of the main body is exposed to ultraviolet irradiation from the photocatalyst filter and the germicidal lamp, and then discharged from the exhaust port of the main body, so the air simply circulates through the main body. I didn't.

Furthermore, as a hot air circulating device that utilizes heat generated from office automation (OA) equipment, a hollow partition is arranged behind the desk on which the OA equipment is installed, and an exhaust fan is provided inside the partition above the desk. At the same time, an exhaust port is opened in the partition above this exhaust fan, an exhaust fan is provided inside the partition below the desk, an exhaust port is opened in the partition below this exhaust fan, and an exhaust port is opened in the partition in front of the partition. An intake port is formed in the vicinity of the partition, and a wind distribution plate for switching the communication between the intake port and the upper exhaust port or the communication between the intake port and the lower exhaust port behind the intake port is provided so that the angle can be adjusted. An air circulating device consisting of the following is disclosed (see Patent Document 3). This technology utilizes two exhaust fans located above and below the desk to absorb the heat generated by OA equipment. The lower exhaust fan warms the room during heating, and locally warms the area around the desk during cooling. It was a device and not a device for local exhaust ventilation.

In addition, a partition panel, an air cleaning mechanism provided in the partition panel, a suction port provided on the surface of the partition panel for taking air into the panel, and a suction port provided on the surface of the partition panel for taking in air in the panel an air outlet for blowing out the air purified by the cleaning mechanism, and a circulation means for guiding part of the air blown out from the outlet to the suction port. A functional partition panel is disclosed (see Patent Document 4). It is a partition panel that is mainly used as a countermeasure against cigarette smoke, and has an intake port at the same height as the mouth. It is a technology that blows out deodorized smoke from the back of the desk through the air cleaning function of the partition panel. This technology also cleans the air, but it is a panel through which the air is circulated.

On the other hand, regarding the air conditioning of the indoor space, a plurality of desks are arranged on the floor surface of the room, and the indoor space air conditioning device individually air-conditions the living area where each desk is arranged. A radiant panel provided on the inner surface, upper surface, or floor surface of the lower space for cooling or heating the lower space, and a radiant panel provided on the floor surface corresponding to each desk, and a temperature and humidity sensor directed toward the lower space of each desk. An indoor space characterized by comprising a floor outlet for blowing out conditioned air from a floor behind the space under each desk, and an air conditioner for supplying temperature-and-humidity-controlled air to the floor outlet. A space air conditioner is disclosed (see Patent Document 5). This technology is an air-conditioning device for multiple desks on the floor, and uses radiant panels to cool or heat the space below the desks, blowing out temperature- and humidity-controlled air from the floor to cool each desk. It is an invention for adjusting the thermal environment according to the preference of each individual who uses it.

Further, an air conditioning system that detects the CO ₂ concentration in the room and operates a ventilator is disclosed (see Patent Document 6).

Japanese Utility Model Publication No. 3-20686 JP-A-11-51430 Japanese Utility Model Laid-Open No. 6-73629 Japanese Patent Application Laid-Open No. 2000-18662 JP 2010-144978 A JP 2020-176797 A

In the midst of the corona crisis, it is necessary to realize a safe and secure learning and working environment without simply relying on ventilation and social distancing. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a table for locally exhausting human exhalation, and a local exhaust system for an indoor space in which human exhalation is locally sucked and exhausted without circulating.

In the above-described prior art, the exhaled air and micro droplets released from the mouth by human breathing and coughing are not locally supplied and exhausted without circulating them. Therefore, by forming an airflow for ventilation of viruses etc. contained in micro droplets from human exhalation, we combined the air intake port and partition of the table so that viruses etc. do not stay, spread or propagate in the indoor environment. The environmental system was considered. In the process, the inventors focused on local air supply and exhaust instead of simply performing ventilation, and found a table with a partition at the back of the table and an intake port at the back of the table top plate. completed.

That is, the present invention is as follows.
[1] a table body;
a box arranged adjacent to the back surface of the table body;
A partition provided on the upper surface of the box,
The box body includes an intake port for sucking the user's exhaled breath, an exhaust port for discharging the exhaled air sucked from the intake port, and the exhaled breath sucked from the intake port to the outside of the box body through the exhaust port. A local exhaust table comprising a fan for exhausting.
[2] The local exhaust table according to [1] above, wherein the table top plate of the table body and the upper surface of the box body are arranged at a horizontal height.
[3] The local exhaust table according to [1] above, further comprising an exhaust path connected to the exhaust port for discharging the exhaled air from the exhaust port to the outside of the room.
[4] The local exhaust table according to [1], wherein the exhaust path communicates with the outside of the room through the floor or ceiling of the room in which the box is arranged.
[5] The local exhaust table according to [1] above, wherein a _CO2 sensor is provided on the table body or the box, and the fan is controlled according to the _CO2 concentration measured by the _CO2 sensor. .
[6] The local exhaust table according to [1] above, wherein the box includes an ultraviolet source that emits ultraviolet rays with a peak wavelength range of 180 to 400 nm or an infrared source that emits infrared rays with a peak wavelength range of 800 to 1100 nm. .
[7] An air conditioner is provided above the room in which the local exhaust table according to [1] is arranged, and the amount of air supplied to the room per unit time by the air conditioner is 2. A local exhaust system for an indoor space, characterized in that the amount of exhaust air is the same as or smaller than the amount of air exhausted from the exhaust port of the local exhaust table.

By using the local exhaust table of the present invention, it is possible to suppress the circulation, retention, or diffusion of air containing human exhaled air indoors, and to exhaust the air to the outdoors.

1 is a perspective view showing an embodiment of a local exhaust table of the present invention; FIG. FIG. 4 is a cross-sectional view of a box and an exhaust passage in the local exhaust table of the present invention; FIG. 4 is a perspective view of a box in the local exhaust table of the present invention; FIG. 4 is a diagram showing an image of the state of use of the local exhaust table of the present invention and the flow of exhaled air; FIG. 4 is a plan view showing a mode in which boxes are arranged on the rear surface and both side surfaces of the table body in the local exhaust table of the present invention; FIG. 3 is a perspective view showing an embodiment having a hood-type partition in the local exhaust table of the present invention; FIG. 3 is a perspective view showing an embodiment of the local exhaust table of the present invention having a partition on the side surface; 1 is a conceptual diagram showing an embodiment of a local exhaust system for an indoor space of the present invention; FIG. Arrows indicate air flow. It is a conceptual diagram seen from the ceiling of the study room in the example. 1 is a conceptual diagram of a local exhaust table of the present invention used in Examples. FIG. FIG. 4 is a diagram showing measurement results of a CO ₂ sensor 27-1 in an example. FIG. 10 is a diagram showing measurement results of a CO ₂ sensor 27-2 in an example. FIG. 4 is a diagram showing measurement results of a CO ₂ sensor 27-3 in an example. FIG. 4 is a diagram showing measurement results of a CO ₂ sensor 27-4 in an example. FIG. 4 is a diagram showing measurement results of a CO ₂ sensor 27-5 in an example. FIG. 10 is a diagram showing measurement results of a CO ₂ sensor 27-6 in an example. FIG. 4 is a diagram showing measurement results of a CO ₂ sensor 27-7 in an example. FIG. 4 is a diagram showing measurement results of a CO ₂ sensor 27-8 in an example.

The local exhaust table of the present invention is
table body and
a box arranged adjacent to the back surface of the table body;
A partition provided on the upper surface of the box,
The box body includes an intake port for sucking the user's exhaled breath, an exhaust port for discharging the exhaled air sucked from the intake port, and the exhaled breath sucked from the intake port to the outside of the box body through the exhaust port. This local exhaust table is characterized by having a fan for exhausting air, and is hereinafter also referred to as "this local exhaust table". Further, the local exhaust system for an indoor space of the present invention includes an air conditioner above the room in which the local exhaust table is arranged, and the amount of air supplied to the room per unit time by the air conditioner is , a local exhaust system for an indoor space, characterized in that the amount of exhaust air per unit time is equal to or smaller than that exhausted from the exhaust port of the local exhaust table; .

Preferred embodiments of the present local exhaust table and the present indoor space local exhaust system will be described below with reference to the drawings. It should be noted that the following embodiments do not limit the present invention, and not all combinations of features described in the embodiments are essential to the solution of the present invention. Furthermore, part of the configuration shown in the embodiment can be combined as appropriate. In addition, the same configuration will be described by attaching the same reference numerals.

■ Local Exhaust Table FIG. 1 is a diagram schematically showing the schematic configuration of the present local exhaust table 1 according to an embodiment of the present invention, and FIG. FIG. 3 is a perspective view of a box, and FIG. 4 is a diagram showing an image of the state of use of the local exhaust table 1 and the flow of exhalation. The local exhaust table 1 includes a table body 11 , a box body 21 arranged adjacent to the rear surface of the table body 11 , and a partition 31 provided on the top surface of the box body 21 . The box body 21 has intake ports 22a and 22b for sucking the exhaled air a of the user who uses the local exhaust table 1, and an exhaust port 23 for discharging the exhaled air a sucked from the intake ports 22a and 22b on the lower surface of the box body 21. , and a fan 24 for discharging the exhaled air a sucked from the intake ports 22 a and 22 b to the outside of the box 21 through an exhaust port 23 . As used herein, exhaled air means air exhaled from the mouth or nose by a person by breathing, sneezing, coughing, or talking. By locally exhausting the exhaled air a, viruses, bacteria, or droplets contained in the exhaled air a can be discharged outside the room.

<Table body>
The table body 11 is a table having a table top plate 12 and supported by table legs 13 . The table top plate 12 of the table body 11 and the upper surface of the box 21 are arranged at a horizontal height. A CO ₂ sensor 27 is provided near the table leg 13 . Note that in this specification, the CO ₂ sensor 27 is provided on the table body 11 or the box 21 not only when the CO ₂ sensor 27 is arranged on the top surface of the table top plate 12 or on the top surface of the box 21. , the case where it is in contact with the table main body 11 or the box 21 in some way, and the case where it is arranged around the table main body 11 or the box 21, for example, within 30 cm.

<Box>
The box 21 has a rectangular parallelepiped shape, and has intake ports 22a and 22b on the top and front surfaces, respectively, and an exhaust port 23 on the bottom. The expired air a is discharged out of the box body 21 through the exhaust port 23 .

The box 21 may be arranged adjacent to the back surface of the table body 11, but as shown in FIG. It may be arranged on the side (not shown).

The box body 21 is arranged horizontally at a height where the upper surface is substantially the same as the table top plate 12 of the table body 11 . In addition, the upper surface of the box 21 may form a predetermined angle toward the rear side of the table body 11 or may be curved.

A mesh-like intake port 22a is provided on the upper surface of the box 21, and user's exhalation is sucked into the box 21 through the intake port 22a. Although there is one rectangular intake port 22a in FIG. 1, the shape of the intake port 22a is not limited to a rectangle, and may be square, elliptical, circular, or linear. Also, the number of intake ports 22a is not particularly limited, and may be one, two, or three or more. Also, the size of the intake port 22a is not particularly limited as long as it does not prevent the user's exhalation from being sucked into the box body 21. As shown in FIG.

An intake port 22a arranged on the upper surface of the box 21 is supported by a fastener 28 so as to have an angle of approximately 45 degrees from the horizontal plane. It can be adjusted to an arbitrary angle such as 30 degrees or 15 degrees by means of a fastener. Also, the intake port 22a may be set at 0 degrees from the horizontal plane, that is, horizontally with the upper surface of the box 21 . By providing the intake port 22a with a predetermined angle, it is possible to improve the efficiency of intake of exhalation a, and to prevent the liquid from spilling into the box body 21 when the user of the local exhaust table 1 spills a liquid such as a drink. It is possible to suppress leakage.

Rectangular mesh-like intake ports 22b are provided at the lower front portion of the box body 21, divided into left and right portions, and opening and closing can be adjusted step by step as necessary. The air intake port 22b allows the user's exhaled air to be taken in when the user's exhaled air does not flow above the table body 11 but flows downward from the front side of the table body 11.例文帳に追加The shape of the intake port 22b is not limited to rectangular, and may be square, elliptical, circular, or linear. Also, the number of intake ports 22b is not particularly limited, and may be one, two, or three or more.

The fan 24 is installed at a position below the intake port 22 b on the bottom surface of the box 21 and forms a flow that draws the user's breath into the box 21 . The fan 24 may be positioned anywhere within the box 21 as long as it can form a flow that draws the user's exhaled air into the box 21 . When the intake port 22b is provided, the fan 24 is positioned below the intake port 22b to prevent the exhaled air a taken from the intake port 22a from leaking from the box 21 through the intake port 22b. becomes possible. Further, when the intake port 22b is not provided, or when the intake port 22b is closed and used, the fan 24 may be arranged above the inside of the box 21 or adjacent to the lower surface of the intake port 22a. Note that the number of fans 24 may be one, two, or three or more.

The box 21 is provided with an ultraviolet light source 25 that emits ultraviolet light with a peak wavelength range of 180 to 400 nm, preferably 220 nm to 315 nm, more preferably 245 nm to 280 nm. Viruses and bacteria contained in the exhaled air a flowing through the box 21 are killed or inactivated by the ultraviolet rays. In addition, the inner surface of the box 21 may be mirror-finished in order to increase the efficiency of ultraviolet irradiation. A light-emitting diode (LED), a mercury lamp, or the like can be used as an ultraviolet light source that emits ultraviolet light. In addition, in combination with ultraviolet rays or instead of ultraviolet rays, predetermined visible light, for example, a visible light source emitting visible light with a peak wavelength of 400 to 800 nm or an infrared light source emitting infrared rays with a peak wavelength of 800 to 1100 nm. It may emit light and/or infrared light, and may emit visible light and/or infrared light instead of ultraviolet light. The generation of ultraviolet rays, visible light, or infrared rays may be pulse waves or continuous waves.

The box 21 is provided with an exhaust passage 26 for discharging the exhaled air a from the exhaust port 23 to the outside of the room. The exhaust passage 26 is connected to the exhaust port 23 and communicates with the outside of the room, and exhaled breath a is discharged outside the room. By providing this exhaust passage 26, the expired air a is not circulated indoors, and it becomes easier to exhaust the expired air a to the outside of the room. The exhaust path 26 may be provided with a pump for sending the air in the exhaust path 26 out of the room. Moreover, the exhaust path 26 may be branched, and the branching can be used to control the amount of air discharged from the exhaust path 26 per unit time. The exhaust path 26 preferably communicates with the outside of the room through the floor or ceiling of the room in which the box 21 is arranged, and the appearance of the floor of the room in which the box 21 is arranged or its surroundings can be improved.

A CO ₂ sensor 27 is installed on the upper surface of the box 21 and under the local exhaust table 1 . The CO ₂ sensor 27 may be installed not only on the top surface of the table top plate 12 or under the present local exhaust table 1, but also on the box body 21 or its surroundings. , may be two or more, or three or more. By measuring the CO ₂ concentration with this CO ₂ sensor 27, the air volume of the fan 24 can be adjusted according to a predetermined CO ₂ concentration. It is possible to increase the air volume of the fan 24 when the CO ₂ concentration is equal to or higher than a predetermined CO 2 concentration, and decrease the air volume of the fan 24 when the CO ₂ concentration is less than the predetermined CO 2 concentration. Also, when the CO ₂ concentration temporarily rises due to the user's coughing, sneezing, etc., the air volume of the fan 24 may be increased for a predetermined period of time. The predetermined CO ₂ concentration in the air volume adjustment of the fan 24 and the air volume adjustment in the air conditioner 41 described later is, for example, 500 to 2000 ppm, preferably 1000 to 1500 ppm. 800 ppm, 900 ppm, 1000 ppm, 1100 ppm or 1200 ppm can be mentioned. When a plurality of CO ₂ sensors 27 are used, the air volume may be adjusted based on the individual CO ₂ concentrations, but the average CO ₂ concentration measured by each CO ₂ sensor 27 is , the airflow may be adjusted based on its average or maximum _CO2 concentration. Also, the CO ₂ sensor 27 may be provided with a light source such as an LED, and the LED or the like may emit color according to the measured CO ₂ concentration. It is possible to visually notify the user of the CO ₂ concentration situation by coloring the LED or the like. Specifically, the LED can be set to emit green light when the measured CO ₂ concentration is less than 1000 ppm, yellow when the measured CO 2 concentration is 1000 ppm or more and less than 1500 ppm, and red when the measured CO 2 concentration is 1500 ppm or more.

<Partition>
A partition 31 with a height of 60 cm is provided on the upper surface of the box 21 . This partition 31 facilitates the flow of the user's exhaled air a to the intake ports 22 a and 22 b and makes it possible to suppress leakage of the exhaled air a to the periphery of the table body 11 . The partition 31 may be fixed so as to extend upward from the rear edge of the upper surface of the box 21, and may be plate-shaped. It may be plate-shaped and partially bent or curved. Moreover, from the viewpoint of the user's field of vision, it is preferable to have transparency, and it is more preferable to be transparent. The height of the partition 31 may be higher than the height of the user's mouth when using the table body, and is, for example, 50 to 70 cm.

Moreover, the partition 31 may be provided not only on the rear edge of the upper surface of the box 21 but also on the side surface of the table body. Further, the partition may be hood-shaped as shown in FIG. By adopting the hood type, it becomes possible to prevent more exhaled air a from leaking out of the table body and spreading droplets around the table body. Furthermore, it is possible to assist the exhaled air a to flow to the intake ports 22a, 22b. In FIG. 6, as the table body 11, two intake ports 22a are provided on the upper surface of the box 21, and a CO ₂ sensor 27 is installed in the center of the upper surface of the box 21. there is Furthermore, as shown in FIG. 7, the partitions 31 are provided on both side surfaces of the table body, and are connected to partitions having a shape extending upward from the rear edge of the upper surface of the box 21 and having a curved upper portion. may be

Two or three or more of the local exhaust tables 1 can be arranged side by side. Such an arrangement allows more exhaled air a to flow to inlets 22a, 22b.

■ Local exhaust system for indoor space <air conditioner>
FIG. 8 is a diagram schematically showing the schematic configuration of the local exhaust system 2 for the indoor space of the present invention. The indoor space local exhaust system includes an air conditioner 41 above the room in which the local exhaust table 1 is arranged, and the amount of air supplied to the room by the air conditioner 41 per unit time is It is characterized by being equal to or smaller than the amount of exhaust air discharged from the exhaust port 23 per unit time. It is preferable that the amount of air supplied into the room per unit time by the air conditioner 41 is smaller than the amount of exhaust air exhausted from the exhaust port 23 per unit time. With the above configuration, air flows from the back and sides of the user to the pollution source so as to envelop the user on the axis connecting the user of the local exhaust table and the assumed pollution source (exhalation, for example). can be made. As a result, it is possible to improve the efficiency of exhausting the pollutants in the room from the exhaust port 23 via the intake ports 22a and 22b. A plurality of this local exhaust table 1 may be installed in the room.

The air conditioner 41 is composed of a blower fan, a heat exchanger, and the like. Here, when there are a plurality of exhaust ports 23, the total amount of exhaust air discharged from each exhaust port 23 to the outside of the room is "the amount of exhaust air discharged from the exhaust ports to the outside of the room per unit time". The ventilation rate of the entire room can be appropriately adjusted according to the size of the room, the standard ventilation rate ^per person of 30 m ³ /hr, and the standards stipulated in the Building Standards Act. Preferably, it can be 250-400 m ³ /hr. The air supply can be the same as the displacement or less than the displacement by 1%, 3%, 5%, 10%, 20%, 30% or 40%. By making the air supply volume lower than the exhaust volume to create a negative pressure in the room, the contamination source will flow smoothly toward the exhaust port.

In addition, the amount of air supplied to the room per unit time by the air conditioner 41 and the amount of air exhausted to the outside from the exhaust port 23 per unit time through the exhaust path are measured by the CO ₂ sensor 27. ₂ concentration can be adjusted. For example, when the concentration of CO ₂ exceeds a predetermined level, the amount of air supplied to the air conditioner 41 and the amount of exhaust air discharged to the outside through the exhaust path 26 are increased, and when the concentration of CO ₂ is less than the predetermined level, can reduce the amount of air supplied to the air conditioner 41 and the amount of air exhausted to the outside through the exhaust passage 26 . Also, when the CO ₂ concentration temporarily increases due to the user's coughing, sneezing, etc., the amount of exhaust air discharged to the outside through the air conditioner 41 and the exhaust path 26 may be increased for a predetermined period of time. .

The air flowing through the exhaust path 26 may exchange heat with the air blown into the room by the air conditioner 41 using a heat exchanger.

[Example]
Using a study room as a model, we measured the ventilation efficiency of a local exhaust system for this indoor space and a commonly used exhaust system with an exhaust port on the ceiling (hereinafter also referred to as "general ventilation system"). The measurement was carried out using the National University Corporation Yamaguchi University School of Medicine library/study room (length 3.7 m x width 4.7 m x height 2.5 m; about 45 cubic meters). FIG. 9 shows a conceptual diagram of the study room as seen from the ceiling. Four study tables 51 are installed in this study room.

Of the four tables 51 (0.85 m long.times.1.1 m wide), the tables 51 shown in the upper left and lower right of FIG. FIG. 10 shows a conceptual diagram of the local exhaust table 1 used in this embodiment. As the partition 31, a partition 31 having a height of 60 cm, which extends upward from the rear edge of the upper surface of the box 21 arranged adjacent to the back surface of the table body 11 and whose upper part is curved, and a partition 31 of the table body 11. A partition 31 with a height of 60 cm extending upward from both sides was fixed. As the box 21, the intake port 22a is arranged on the upper surface of the table body 11, and the box 21 is provided with a rectangular mesh-like intake port 22b on the lower front surface. Furthermore, the exhaust port 23 provided in the box 21 is connected to the exhaust path 26, and is structured to exhaust outside the room through the exhaust path 26 under the floor (not shown in FIGS. 9 and 10). Incidentally, in the case of the table 51 shown in the lower right of FIG. 9, the intake port 22b was closed and air was sucked only through the intake port 22a.

In this experiment, crushed dry ice was placed at a height of 15 cm on the top plate of the table 51, assuming the exhalation of the user of the upper left table 51 (this local exhaust table 1) in FIG. 9, and CO ₂ was generated. let me In FIG. 9, 6 locations (110 cm above the floor) indicated by black circles, 1 location above the table top of the table 51 indicated by white circles, and 1 location below the table top of the table 51 indicated by gray circles, for a total of 8 locations. By installing CO ₂ sensors 27-1 to 27-8 in the study room and monitoring the concentration of CO ₂ in the study room in real time, the distribution of CO ₂ in the indoor space in the local exhaust system and the general ventilation system of the indoor space , the diffusion and retention conditions were evaluated.

Next, the ventilation structure of the study room will be described. First, with regard to air supply, the same amount of air is supplied from four air conditioners 41 in the study room in the horizontal direction so that the blown air does not easily interfere with each other. Next, in the case of the local exhaust system for the indoor space, the two tables 51 (local exhaust table 1) are exhausted from the exhaust port 23 at 150 m ³ /hr each, for a total of 300 m ³ /hr. In this case, exhaust was performed at 300 m ³ /hr from a ceiling exhaust port (not shown) provided on the ceiling above the place where the CO ₂ sensor 27-2 was installed. The amount of air supplied to the room was the same in both the case of the local ventilation system for the indoor space of this case and the case of the above-mentioned general ventilation system, and the indoor space was made negative pressure by making it smaller than the exhaust amount. That is, the local exhaust system and the general ventilation system of the indoor space of this case, the air supply amount is the same condition, the exhaust amount is the same condition, and the air supply from the air conditioner 41 from the vicinity of the ceiling is the same condition. While the air is exhausted through the local exhaust table 1, the latter is exhausted from the ceiling exhaust port.

Next, the procedure for monitoring the concentration of CO ₂ in the study room in real time is shown below.
(1) The positions of the eight CO ₂ sensors 27-1 to 27-8 were fixed and measured throughout the entire experiment. The room temperature was adjusted to about 20° C. with an air conditioner installed on the ceiling of the room before the measurement.
(2) The air conditioner was turned off, and about 400 g of dry ice crushed finely with a wooden mallet was placed at a height of 15 cm above the top plate of the upper left table 51 in FIG.
(3) After the CO ₂ sensor 27-2 on the inlet side indicates 1500 ppm, air is supplied by the air conditioner 41 and the local exhaust table 1 (in the case of the local exhaust system for the indoor space) or the ceiling exhaust port (general ventilation system In the case of ), exhaust from the room was started at the same time, and the experimenter went out of the room.
(4) While measuring the CO ₂ concentration, the measurement data was recorded and saved in a personal computer. Changes in CO ₂ concentration over time were measured for 4000 seconds with a sampling period of 30 seconds.

<Measurement result>
First, the measurement results of the CO ₂ sensors 27-1 to 27-8 installed on the table top are shown in FIGS. 11-1 to 11-8, respectively. The horizontal axis is the elapsed time (seconds) from the start of air supply and exhaust, and the vertical axis is the CO ₂ concentration. In addition, in Figures 11-1 to 11-8, the black line is the _CO2 concentration measured by the local exhaust system in the indoor space (described as "local CO2" in each figure), and the gray line is the overall ventilation system. _CO2 concentration measured in (denoted as "total CO2" in each figure)

From the results of Figure 11-3 (corresponding to CO ₂ sensor 27-3), in the case of the local exhaust system of the indoor space, the position close to CO ₂ generation by dry ice is only 450 seconds after the start of air supply and exhaust. Nevertheless, the _CO2 concentration dropped below 1000 ppm, 600 seconds (10 minutes) after the start the _CO2 concentration dropped below 800 ppm, and 1000 seconds after the start the _CO2 concentration dropped below 600 ppm. Moreover, after that, the CO ₂ concentration was maintained at 600 ppm or less despite the continued generation of CO ₂ by dry ice. On the other hand, in the general ventilation system, the CO ₂ concentration was 900 ppm or more even 1000 seconds after the start of air supply and exhaust, and did not fall below 600 ppm even after 3000 seconds. The CO ₂ sensor 27-3 is the position of the user of the table, and from the above results, it was confirmed that the user can learn in a well-ventilated environment by using the present local exhaust table 1. In addition, while it is desirable for users to enter the room and learn in a well-ventilated environment in a short time, the fact that the CO ₂ concentration can be reduced to 600 ppm or less in 900 seconds (15 minutes) after the start is a short time. It can be said that it is possible to provide an environment with sufficient ventilation for all study room users.

Furthermore, in Figure 11-4 (corresponding to CO ₂ sensor 27-4), in the case of the local exhaust system for the indoor space, the CO ₂ concentration decreased to 1000 ppm or less 300 seconds after the start of air supply and exhaust. , the _CO2 concentration dropped below 800 ppm at 600 seconds after the start, and below ₆₀₀ ppm at 900 seconds after the start. Moreover, after that, the CO ₂ concentration was maintained at 600 ppm or less despite the continued generation of CO ₂ by dry ice. Also, in Figure 11-1 (corresponding to CO ₂ sensor 27-1) and Figure 11-6 (corresponding to CO ₂ sensor 27-6), in the case of the local exhaust system for the indoor space, air supply and exhaust 600 seconds (10 minutes) after the start of the _CO2 concentration dropped below 800 ppm, and 1000 seconds after the start of the _CO2 concentration dropped below 600 ppm. On the other hand, in the general ventilation system, the CO ₂ concentration was 800 ppm or more even 1000 seconds after the start of air supply and exhaust, and did not fall below 600 ppm even after 3000 seconds. From these results, in the case of the local exhaust system for the indoor space, not only at the position of the local exhaust table 1, but also near the user of the adjacent table, the user is in a sufficiently ventilated environment. It was confirmed that learning can be done in

In Figure 11-2 (corresponding to CO ₂ sensor 27-2) and Figure 11-5 (corresponding to CO ₂ sensor 27-5), in the case of the local exhaust system for the indoor space, air supply and exhaust start 700 seconds later, the _CO2 concentration dropped to 800 ppm or less, and 1500 seconds after the start, the _CO2 concentration dropped to 600 ppm or less. Moreover, after that, the CO ₂ concentration was maintained at 600 ppm or less despite the continued generation of CO ₂ by dry ice. On the other hand, in the general ventilation system, the CO ₂ concentration was 800 ppm or more even 1000 seconds after the start of air supply and exhaust, and did not fall below 600 ppm even after 3000 seconds. From these results, surprisingly, in the case of the local exhaust system for the indoor space, it was confirmed that an environment with a CO ₂ concentration of 600 ppm or less could be maintained even at a position distant from the local exhaust table 1. . From the above results, it was clarified that the circulation, retention, diffusion, or propagation of CO ₂ in the room was suppressed in the case of the local exhaust system for the indoor space.

In Figure 11-7 (corresponding to CO ₂ sensor 27-7), in the case _of the local exhaust system of the indoor space, the air supply and After 900 seconds after the start of evacuation, the _CO2 concentration remained below 1400 ppm. On the other hand, in the general ventilation system, the concentration did not fall below 1400 ppm even after 3000 seconds from the start of air supply and exhaust. From these results, it is clear that CO ₂ tends to flow to the lower side of the table, and providing the intake port 22b at the front lower portion of the box 21 in the present local exhaust table 1 is effective for increasing the exhaust efficiency. It was shown that there is

In FIG. 11-8 (corresponding to CO ₂ sensor 27-8), in the case of the local exhaust system of the indoor space, although it is located near the CO ₂ generation due to dry ice, the air supply and exhaust 400 seconds after the start of the _CO2 concentration dropped below 1000 ppm, 600 seconds after the start the _CO2 concentration dropped below 800 ppm, and 1000 seconds after the start the _CO2 concentration dropped below 600 ppm. Moreover, after that, the CO ₂ concentration was maintained at 600 ppm or less despite the continued generation of CO ₂ by dry ice. On the other hand, in the general ventilation system, the CO ₂ concentration was 800 ppm or more even 1000 seconds after the start of air supply and exhaust, and did not fall below 600 ppm even after 3000 seconds. From these results, in the case of the local exhaust system for the indoor space, it is possible to maintain an environment with a CO ₂ concentration of 600 ppm or less even in the vicinity of the CO ₂ generation source and on the table top. It was confirmed that ₂ was difficult to stay on the table top.

Local exhaust table 1
Indoor space local exhaust system 2
table body 11
table top 12
table leg 13
box 21
Intake ports 22a, 22b
exhaust port 23
fan 24
UV source 25
exhaust path 26
CO ₂ sensor 27, 27-1~27~8
fastener 28
Partition 31
air conditioner 41
table 51
Exhalation a

Claims (7)

table body and
a box arranged adjacent to the back surface of the table body;
A partition provided on the upper surface of the box,
The box body includes an intake port for sucking the user's exhaled breath, an exhaust port for discharging the exhaled air sucked from the intake port, and the exhaled breath sucked from the intake port to the outside of the box body through the exhaust port. A local exhaust table comprising a fan for exhausting. 2. The local exhaust table according to claim 1, wherein the table top plate of the table main body and the upper surface of the box are arranged at a horizontal height. 2. The local exhaust table according to claim 1, further comprising an exhaust passage connected to said exhaust port for exhausting said exhaled air from said exhaust port to the outside of the room. 2. The local exhaust table according to claim 1, wherein the exhaust path communicates with the outside of the room through the floor or ceiling of the room in which the box is arranged. 2. The local exhaust table according to claim 1, wherein a _CO2 sensor is provided on the table body or the box, and the fan is controlled according to the _CO2 concentration measured by the _CO2 sensor. 2. The local exhaust table according to claim 1, further comprising an ultraviolet generation source that emits ultraviolet rays with a peak wavelength range of 180-400 nm or an infrared radiation source that emits infrared rays with a peak wavelength range of 800-1100 nm in the box body. An air conditioner is provided above a room in which the local exhaust table according to claim 1 is arranged, and the amount of air supplied to the room per unit time by the air conditioner is equal to the local exhaust air per unit time. A local exhaust system for an indoor space, characterized in that the amount of exhaust air is the same as or smaller than that exhausted from an exhaust port of a table.