JP7082497B2 - Environmental load reduction type outside air introduction system - Google Patents

Description

The present invention relates to a technique for reducing energy loss in building air conditioning. In particular, it relates to a technique for reducing energy loss of building air conditioning associated with the installation of a fume hood.

The fume hood is an enclosure-type local exhaust device for laboratories that captures harmful gases, vapors, odors, and dust generated in the laboratory with a source so that they are not dispersed in the room. There are laws and regulations depending on the chemicals used and the application. Recently, in consideration of health, the surface wind speed on the front of the sash has been increased to prevent the organic solvent from leaking from the fume hood into the room.
In this amendment, it is generally required to secure the surface wind speed of the opening where the experimental work is performed.
For example, according to the rules for preventive measures against damage to specified chemical substances, in a fume hood of the enclosed hood type, 0.5 m / sec or more for gaseous substances and 1.0 m / sec for particulate substances. Yes, according to the Organic Solvent Poisoning Prevention Regulations, it is 0.4 m / sec. Each target drug is also specified.
There is a type of fume hood that mainly has a fixed-quantity exhaust without an intake function, and since it does not have an intake function, the number of installed units is limited depending on the size of the room. In addition, the loss of conditioned air increases due to constant exhaust gas.
There is an air curtain method as a method for saving energy by replenishing the conditioned air in the room exhausted from the draft chamber by the outside air. Stable surface wind speed cannot be obtained, and its use is limited.
In Patent Document 1 (Japanese Unexamined Patent Publication No. 7-34763), an air curtain box 7 is provided on the upper front surface of the fume hood main body 2, and the air supply port 9 formed on the upper surface thereof communicates with the outside of the laboratory to force outside air. The air supply duct 8 to be supplied to the air supply duct 8 is connected to the air supply duct 8, and the lower surface side air supply port 14 and the rear surface side air supply port 15 are provided on the lower surface and the back surface, respectively, and the outside air forcibly supplied from the air supply duct 8 is supplied. As a retention means, resistance plates 21, 22, and 23 made of a breathable material are provided in a plurality of stages while blocking the ventilation passage 10 in the air curtain box 7, and the lowermost resistance plate 23 is the front opening of the draft chamber main body 2. A draft chamber provided in a state of being inclined toward No. 3 is disclosed. This draft chamber is an air-conditioning type fume hood, and by slowing the wind speed of the outside air supplied from the air-curtain box evenly and on average, it does not cause discomfort to the experimenter and is indoors. It is stated that the processing chamber of the fume hood can be effectively exhausted without disturbing the air conditioning.
The fume hood of Patent Document 2 (Japanese Unexamined Patent Publication No. 2015-9187) is a low air volume draft chamber that sends low air volume air to the work space in order to work in the work space, and has a fan that sends air to the work space and a fan. A low air volume fume hood provided with a rectifying member as a rectifying means for rectifying the air from the fan is disclosed between the working space and the working space. It is stated that in this fume hood, air can be passed in a low air flow draft into the work space for workers to carry out experiments and work so that the atmosphere inside the fume hood does not leak to the outside. There is.
In Patent Document 3 (Japanese Unexamined Patent Publication No. 2007-175583), a main body 1 having an opening 2 on at least one surface of an outer peripheral portion of a work space S having a substantially rectangular plan view and air in the work space S are introduced upward. A fume hood 25 (31) provided with an exhaust means 11 for suction removal to eject air toward the central portion of the work space S at a portion of the periphery of the work space S facing each other across the central portion in a plan view. ) Is provided to realize a draft chamber having excellent emission and removal properties of toxic gases.
Patent Document 4 (Japanese Unexamined Patent Publication No. 2008-229474) discloses a fume hood in which an intake fan is provided above the housing and an exhaust fan is provided below.
In Patent Document 5 (Japanese Unexamined Patent Publication No. 2010-115580), a hood extending in the horizontal direction is provided at the upper end of the front surface of the draft chamber, so that the wind blown out from the air outlet of the air conditioner flows into the draft chamber. It is stated that the air flow flowing into the fume hood is prevented from being turbulent so as not to hit the fume hood, and the toxic gas is prevented from leaking from the inside of the fume hood.

As a result of increasing the suction power of the fume hood and increasing the exhaust volume in an attempt to secure the surface wind speed so that harmful substances do not diffuse into the room, the amount of air-conditioned air in the room where the draft chamber is installed increases. , The air conditioning load is increasing. That is, the result is that the environmental load increases.

Japanese Unexamined Patent Publication No. 07-034763 Japanese Patent Application Laid-Open No. 2015-009187 Japanese Unexamined Patent Publication No. 2007-175583 Japanese Unexamined Patent Publication No. 2008-229474 Japanese Unexamined Patent Publication No. 2010-115580

An object of the present invention is to develop an environmental load reduction type outside air introduction system that reduces suction and exhaust of conditioned air in a room due to an increase in suction and exhaust capacity of a fume hood and the like.

In the present invention, the outside air supply unit is provided with an opening for attracting indoor air, and the air curtain that blows out toward the opening of the draft chamber is formed into an air curtain having a high concentration layer of outside air and a high concentration layer of indoor air. be.
In the present invention, the airflow sucked into the fume hood is mainly the outside air portion, and the airflow circulating in the room is mainly the conditioned air. It is an invention which provides a mold outside air introduction system. Further, since the high concentration layer of indoor air hits the user of the fume hood, it is difficult to be exposed to the outside air of high temperature and low temperature which is not air-conditioned, and the working environment is also good.
The main configurations of the present invention are as follows.
1. 1. An air supply unit for a fume hood that forms an air curtain with an air curtain that takes in outside air into the room and blows it out toward the opening of the fume hood as a high-concentration layer of outside air and a high-concentration layer of indoor air .
Equipped with an outer cylinder that communicates with the outside air and an air outlet,
A suction port facing the room is provided between the outer cylinder and the outlet, and a throttle mechanism is provided on the upstream side of the suction port to increase the speed of the outside air. An air supply unit that draws into the unit and creates an air curtain consisting of outside air and indoor air.
2 . 1. It is characterized by having an outlet grill that regulates the direction of the air blown out to the air outlet of the air supply unit. The listed air supply unit.
3 . The air supply unit is equipped with a rectifying plate, an attracting plate, a suction port, and a blowout grill from the upstream side in the direction of air flow.
The straightening vane has a large number of pores and
The attract plate is provided with a throttle opening that throttles the airflow that has passed through the straightening vane.
The blowout grill has a louver that regulates the direction of the blown air,
It is characterized by 1. Or 2. The air supply unit described in.
4 . It is characterized by providing an inclined plate between the suction port and the air outlet. ~ 3 . The air supply unit described in any of.
5 . 1. 1. ~ 4 . An environmental load reduction type outside air introduction system characterized in that the air supply unit described in any of the above is arranged above the opening surface of the fume hood.
6 . The air curtain blown out from the air supply unit is a multi-layer flow, the opening surface side of the draft chamber is the outside air high concentration layer, and the indoor side is the indoor air high concentration layer.
It is characterized in that the surface wind speed of the opening surface of the draft chamber is controlled to 0.4 m / sec or more. The described environmental load reduction type outside air introduction system.
7 . The air circulating in the room is characterized by containing a high concentration layer of indoor air. The described environmental load reduction type outside air introduction system.

1. 1. The present invention provides an air supply unit that introduces outside air into a room and mainly supplies outside air to equipment such as a fume hood. We created an air curtain in which the mixed concentration of the air-conditioned air layer and the outside air layer that are air-conditioned in the room is offset, and let the draft chamber suck in the part with a high outside air concentration so that the part with a high air-conditioned air can be circulated indoors. be.
As a result, when a device such as a fume hood that sucks and exhausts air is used, it is possible to realize an environmental load reduction type outside air introduction system that reduces suction and exhaust of conditioned air in the room. In other words, there is no loss of energy for air conditioning, which is energy saving.
2. 2. An air curtain having an outside air layer portion and an conditioned air layer portion made from the main air supply unit, and by arranging the workers so as to be located in the conditioned air layer portion, the environment of the workers should be kept good. Can be done. You will not be exposed to the cold outside air in winter or the hot outside air in summer.
3. 3. In particular, the surface wind speed of the fume hood has been revised to a high level so that organic solvents and the like do not leak to the indoor side, so that the displacement is increasing. By reducing the amount of indoor air exhaust while ensuring this surface wind speed and discharging the outside air introduced from the air supply unit through the draft chamber, the load on the air conditioning system of the building can be reduced.

The figure which combined the air supply unit and the fume hood is shown. The figure which shows the structure and the air flow of the air supply unit joint fume hood. The figure which shows the structure of an air supply unit. A perspective view of the air supply unit and an enlarged view of the main part are shown. A perspective view (partially broken view) of a fume hood with an air supply unit is shown. The figure which shows the surface wind speed measurement test of the sash opening surface. The figure which shows the air curtain wind speed measurement test result. The figure which shows the air flow and temperature distribution of an air curtain. Fume hood installation equipment air conditioning flow schematic diagram. The figure which shows the conventional example.

The present invention is an air supply unit that supplies outside air to a fume hood or the like. It is stipulated that equipment such as fume hoods should be sucked and exhausted so that harmful substances such as organic solvents do not leak into the room. Recently, the surface wind speed of the opening for work has been increased, and the amount of air discharged has also increased. Along with this, the air in the air-conditioned room is also exhausted, so the load on air conditioning in the building is also increasing.
On the other hand, in the fume hood, the air curtain method is not widespread, and it is not possible to secure the surface wind speed and prevent the disturbance due to the outside air.

The present invention is an air supply unit that takes in the outside air to be supplied and the indoor air into a housing to create an air curtain having a layer structure of an outside air layer portion and an conditioned air layer portion.
The air supply unit of the present invention rectifies the outside air taken in from the outside through the duct upstream in the housing, takes in the indoor air from the opening provided on the middle side surface of the housing, and with respect to the suction opening such as the draft chamber. And make an air curtain that urges and blows away.
This air supply unit enters from the upstream side in the housing of the air supply unit, and draws indoor air through an opening provided in the front of the housing in the middle of the air curtain formed by being ejected from the outlet. It is to be a part of. The present invention focuses on the phenomenon that indoor air is attracted to the flow of outside air having a high wind speed.
Since the outside air is pushed out by the power of a fan or the like, it is in a turbulent state, and since the indoor air is drawn into the turbulent flow, it does not necessarily form a layer, and the outside air and the indoor air flow in a dumpling state or a mixed state. .. In the present invention, the outside air is first rectified to a uniform state through the pores, the rectification is accelerated to flow down, and the indoor air is drawn in from the opening to form a layer between the outside air layer portion and the indoor air portion. Created an air flow.
The airflow that takes in the indoor air passes through the cross section narrowed by the inclined plate, the wind speed further increases, and the attractive force of the indoor air increases.
Then, by angling the blowing direction of the air curtain toward the inside of the room with the grill, the outside air portion reaches below the opening of the draft chamber.
As a result, the outside air portion is sucked into the fume hood, and the conditioned air portion flows downstream along the worker so as to circulate in the room.

The outline of the present invention is shown in FIG.
The draft chamber 100 is installed in a laboratory or the like provided in the building. The air supply unit 1 is attached to the fume hood 100. The air supply unit 1 is connected to an external air supply 110 that takes in outside air. An attraction opening 2 is provided in the middle of the side portion of the air supply unit 1, and an air curtain 130 is blown out from the lower end.
A sash opening 102 is provided on the front surface of the draft chamber 100 so that an operator can work from the opening. It is exhausted from the upper surface of the draft chamber and connected to the exhaust system 120. As shown in FIG. 9, the intake / exhaust system of the building is a system that takes in outside air and a system that decontaminates the exhaust / exhaust system.
While the outside air taken in from the upper part of this air supply unit is flowing down, the indoor air is drawn in from the suction opening and the air curtain is blown out from the lower part. The flow on the draft chamber side of the air curtain is sucked in from the sash opening and exhausted. An air curtain is formed in which the indoor air drawn from the suction opening flows to the worker side and the outside air flows to the draft chamber side. Therefore, it is sucked into the draft chamber from the layer of the outside air. The air curtain airflow shown in FIG. 1B is an example shown in the test example. The air flow shown in FIG. 1 (b) is opposite to the direction of the fume hood shown in FIG. 1 (a).
Therefore, by attaching an outside air introduction type air supply unit laid in the building to the draft chamber not provided with the air curtain, it becomes an environmental load reduction type outside air introduction system capable of reducing the exhaust of the conditioned air.

[Embodiment 1]
8 to 8 show an embodiment in which the air supply unit 1 is attached to the fume hood 100. The structural cross section of the air supply unit 1 is shown in FIG. An outer cylinder 12 is provided above the back surface of the housing 11, a suction port 2 is provided in the middle of the front surface, a blowout grill 6 is provided at the lower portion, and a blowout port 13 is provided on the lower surface. A straightening vane 3 is provided above the inside, an attraction plate 4 is provided above the suction port 2, and an inclined plate 5 is provided on the back surface below the suction port 2. The direction of the air supply unit 1 is the working opening side (that is, the side on which the worker stands is "front") in the state of being attached to the draft chamber.
Each member is shown in FIG. 3 (b).
The outer cylinder 12 is a widening duct connected to a square cylinder-shaped air conditioning duct, and is provided in two in this example. For the straightening vane 3, a small hole plate 31 such as a punching metal provided with a large number of pores is used. The attract plate 4 is formed with a plurality of throttle openings 41 for squeezing and accelerating the outside airflow.
The suction port 2 is provided with a plurality of plates whose inner surface side is inclined downward in parallel in a slit shape. In this example, the slit is divided in the width direction. A plurality of plates can be provided with a louver function that can be adjusted to open and close. The suction port 2 is arranged below the attraction plate 4.
The inclined plate 5 is a plate body inclined downward, and a plurality of inclined plates 5 are provided in this example. The inclined plate 5 is located below the suction port 2. The number of inclined plates is arbitrary. The airflow flowing in the housing is guided by the inclined plate, changes its direction, and becomes a direction along the inclined direction of the lower grill to generate an air curtain having a stable blowing direction.
The blowout grill 6 is formed of a large number of plates. In this example, it is provided so as to be inclined forward. The air flow may be divided in a grid pattern.

FIG. 4 shows a perspective view (a) and an enlarged view (b) of the internal mechanism of the air supply unit 1.
An outer cylinder 12 is provided above the rear surface of the housing 11, a suction port 2 in which a plurality of triangular openings are arranged is provided in the middle portion of the entire surface, and the lower part of the housing is open. The outside air that has entered from the outer cylinder 12 and the indoor air that has entered from the suction port 2 are blown out as an air curtain from the lower opening. By opening and closing the louver provided in the suction port 2, the amount of indoor air drawn from the suction port can be adjusted.
Inside the housing 11, a straightening vane 3, an attracting plate 4, an inclined plate 5, and a blowout grill 6 are provided in this order from above.
In the illustrated example, the straightening vane 3 is composed of a small hole plate 31 which is two plates provided with a large number of small holes. The incentive plate 4 is provided with a diaphragm opening 41 which is a large opening. A thin plate is provided on the blowout grill 6 so as to be inclined in parallel.

An example of the fume hood 100 combined with the air supply unit 1 is shown in FIG. FIG. 5 shows the perspective view.
The draft chamber 100 is a general one, and is a box body, and the inside 101 of the draft chamber is divided into three upper and lower stages. A work surface 103 is provided in the middle at a height that makes it easy to work, and an exhaust opening is provided by partitioning the upper part. The intermediate space becomes the work space 105. The work space 105 is provided with an opening 102 so that the worker M can access it, and a shutter 104 for opening and closing the opening 102 is provided. This opening 102 is usually referred to as a sash surface. The rear exhaust passage 106 is provided on the rear side.
The fume hood serves as an enclosure-type local experimental exhaust function that captures harmful substances such as toxic gas, steam, odor, and dust generated in the work space 105 at the source so as not to diffuse into the room. As explained in the background technology section, the surface wind speed of the sash surface is specified so that such harmful substances do not diffuse into the room.
The outline of the air flow of the draft chamber 100 will be described.
The total amount of air flowing through the refrigerator 101 is determined by the amount of exhaust 140 exhausted to the outside of the fume hood. The air supply point is mainly the surface wind 141 entering from the opening 102, and in this example, the lower surface wind 142 taken in from the lower surface apron 122 of the workbench is assisted. This bottom wind 142 is not always necessary. The lower surface wind 142 is sent out from the lower surface wind guide portion 145 provided at the lower part of the work surface 123.
The air taken into the work space 105 becomes an internal wind 143 containing harmful substances, passes through the rear exhaust passage 106 provided on the back surface of the work space 105, rises to become an exhaust 140, and is drafted. It is sent out of the chamber. Since the exhaust containing this harmful substance cannot be discharged to the outside air as it is, an exhaust treatment device such as a scrubber (see FIG. 9) is installed in the building.

FIG. 2 shows the air flow in a state where the air supply unit 1 and the fume hood 100 are combined. The air supply unit 1 is attached above the opening 102 (shutter 104) of the fume hood 100. In this state, the air flow in the air supply unit 1, the air curtain, and the fume hood will be described.
The external intake air 110 taken in from the outer cylinder 12 of the air supply unit 1 is rectified by the rectifying plate 3 from a turbulent flow state to a uniform state. At least due to the outer cylinder 12 widened from the duct, the widened external intake 111 is turbulent at the upper part of the housing. If you touch the indoor air drawn in in a turbulent state, it will mix or become meandering. The outside air in this turbulent state is controlled through the straightening vane to make it a straight flow. In this example, many small streams that extinguish the momentum of the turbulent flow are made through the small hole plate 31 with a fine opening. Through the attract plate 4 provided with the large throttle opening 41, the trickles are collectively flowed downward as a flow of outside air having a high wind speed.
Negative pressure is generated by the accelerated wind speed of the outside air, and the indoor air 113 is drawn from the attraction opening 2. It becomes an air flow 112 due to the indoor air drawn from the suction port 2 and the outside air. At this time, since the suction ports 2 are drawn from a plurality of slits provided in the horizontal direction, the laminar flow generated by the upper slit to the lower slit is sequentially in contact with the outside airflow. Since the outside air that has passed through the attract plate is in a thick bundle and has momentum, both of them are layered and flow downward without being disturbed by the pressure of the drawn indoor air 113.

Next, the airflow passes through the narrowed cross-sectional space by the inclined plate 5, the wind speed is further accelerated, and the attractive force from the suction port 2 is increased to become the corrected airflow 114. In the illustrated example, the inclined plate is provided in three stages, but the installation location and the number of stages are determined by factors such as the flow of the air curtain, the intake air (plane wind speed) drawn into the fume hood, and the induced indoor flow. ..
The outlet 13 is provided with an outlet grill 6. The longitudinal plate forming the blowout grill is inclined outward so that the air curtain 130 becomes a laminar flow urged away from the opening surface of the fume hood. The angle of the air curtain is directed outward so that the air curtain, especially the high-concentration outside air, reaches the lower part of the opening of the fume hood.
When the air curtain is divided into an inner airflow 131 and an outer airflow 132 near the fume hood side, the inner airflow 131 has a high concentration of outside air 111, and the outer airflow 132 has a high concentration of indoor air 113. The inner airflow 131 flowing down along the opening 102 of the draft chamber 100 is sequentially drawn into the draft chamber, and the outer airflow 132 flows down to the feet of the worker and circulates in the room.
The fact that the air curtain is in a laminar flow state, that it is drawn in from the fume hood side, and that the temperature distribution of the flowing airflow is confirmed by the test results shown in FIG.
In this example, the grill is further formed in a mesh shape to make a fine flow and soften the contact with the worker.

Each component of the air supply unit 1 is formed in an air curtain in which the taken-in outside air and the indoor air are layered. The outside air is taken in by using the power of a fan or the like.
As described above, the air supply unit once divides the outside air, which is taken in through the outside air duct and becomes a turbulent flow, into small small streams to extinguish the momentum of the turbulence. After that, it passes through an attraction plate provided with a plurality of large throttle openings, and the outside air becomes an accelerated large bundle of fast wind speed airflows.
The airflow in the duct taken in by the rotation of the fan and the influence of the wind pulsates and spreads from the duct to the upper part of the housing, resulting in turbulence. This is passed through a small hole to resist the airflow, and the flowing wind power is divided into small pieces to adjust the wind speed and direction. In the illustrated example, the small hole plate is provided with a large number of small circular openings in the plate-like body, but the openings may be provided by drilling a cylindrical hole in a thick plate. The shape of the opening may be a honeycomb-shaped hexagon or the like. Honeycomb core material can also be used. Further, a plurality of straightening vanes can be provided and adjusted. As the material, metal, resin, or paper is used.

The attraction plate has a larger opening than the straightening vane. Blow out from a large opening to make a large bundle of outside air.
Further, by making the opening ratio of the attracting plate smaller than the opening ratio of the straightening vane, the wind pressure can be increased to blow out. The outside airflow that has passed through the attract plate functions to draw the indoor air into the air supply unit by utilizing the wind speed difference in the next process, so it is necessary to secure the wind speed. The present inventor also conducted a test in which the outside air was allowed to flow without providing the attraction plate, but the indoor air drawn in was not stable, and the outside air sometimes blew out from the suction port.
The material and shape of the attract plate are the same as those of the straightening vane.
It is possible to prepare multiple types of rectifying plates and attracting plates and adjust them together with the draft chamber.

The inclined port 2 is provided on the front side of the air supply unit 1 in this example. A plurality of horizontal slits are formed in the suction port. The air in the room is taken into the housing from the suction port due to the difference in speed from the outside air flowing down from above the housing 11. The plate forming the slit is tilted to guide the air taken in downward. This suppresses the mixing of the outside air and the indoor air, and keeps the outside air layer and the indoor air layer.
By using a plurality of slits, a parallel flow without turbulence can be formed. In addition, the width direction of the slit is divided to create a short air flow, the influence on the outside air flow is reduced, and the flow of the outside air and the room air becomes a layer.

The inclined plate 5 functions to change the airflow direction toward the blowout grill 6 inclined outward, and forms a parallel layered air curtain 130 without turbulence from the grill. The airflow that flows through the housing is pushed back by the indoor air that enters from the suction port 2, and is pushed back by the inclined plate to control the blowing direction of the air curtain in cooperation with the grill.
The blow-out grill 6 is installed so as to be inclined outward, and the air curtain is urged to slightly bend the opening surface of the draft chamber to blow out against the suction force of the draft chamber.
The air curtain 130 is composed of an inner airflow 131, which is a layer mainly composed of indoor air, and an outer airflow 132, which is a layer mainly composed of outside air.
The inner airflow 131 flows on the worker side and circulates in the room. In addition, it suppresses the adverse effects of temperature differences on workers.
The external airflow 132 flowing along the opening surface of the draft chamber becomes a surface wind 141 from the opening 102 of the draft chamber and is taken into the refrigerator to prevent the outside air from diffusing into the room.
Therefore, since the indoor air exhausted from the draft chamber can be reduced, it is possible to realize an outside air introduction system that can prevent the wear of energy for air conditioning and reduce the environmental load.

In the process of studying the present invention, various types of outside air supply formats were studied.
The supply types examined are, for example, (a) a type that blows out outside air from the ceiling surface of the draft chamber, (b) a type that blows out from the top and bottom, (c) a type that blows out from both the left and right sides, and (d) a type that blows out from the top and bottom and both sides. , (E) The upper hood type (prototype of the present invention) was simulated.
As a result of evaluating the wind speed distribution on the sash opening surface, the outside air suction (exhaust) rate, the temperature distribution around the operator, etc., the upper hood type was superior to the other types in terms of the outside air suction rate and the surface wind speed. Based on this result, we examined how to improve the work environment and improve the degree of perfection.

<Test 1>
(Draft chamber surface wind speed test)
(1) A test was conducted to measure the surface wind speed of the fume hood under the following conditions shown in FIG. 6 (a).
Opening surface: 400 x 1640 mm
Measurement point location: 8 points Measurement start point: Lower left side Sensor arrangement: Width direction: 205 mm to 410 mm pitch
Height: B row 100 mm, A row 300 mm
Wind speed conditions Exhaust air volume: 1200m ³ / h
Air curtain Intake air volume: 1200m ³ / h

(2) The test results shown in FIG. 6 (b) were obtained.
The maximum surface wind speed is 0.72 m / s, the minimum surface wind speed is 0.5 m / s, and the average surface wind speed is 0.63 m / s, which satisfies the conditions of the minimum surface wind speed of 0.5 m / s or more in the specialization rule. You can see that.
In particular, row A, which is the upper opening, had a wind speed of 0.70 m / s or more. The lower opening was 0.50 to 0.60 m / s. The wind speed is stable with little variation between the top and bottom.
Since the intake and exhaust are set to the same amount, it can be seen that they are pulled into the draft chamber from the portion along the opening surface of the draft chamber. In tests 2 and 3, it is confirmed that an air curtain in which the outside air and the indoor air are layered is formed.

<Test 2>
(Indoor air suction amount test)
The air supply unit used in this test has a total width of 1800 mm and a depth of 220 mm. The suction port 2 is provided with a louver that can be opened and closed. In this test, the amount of indoor air sucked is confirmed by opening and closing the louver.
Ten wind speed measurement sensors were installed at the outlet 13 at the lower end of the air supply unit 1 to measure the wind speed of the air curtain. The sensors at both ends were arranged at 22 mm from both ends, and 10 sensors were arranged at equal intervals of 195 mm. The air outlet is divided into 10 parts, and the air volume of the entire air outlet in time units is calculated based on each wind speed.
The test air volume was set with the suction port 2 fully open and the air curtain air volume set to 1200 m ³ / h, and the slit of the suction port 2 was half-opened and fully opened.

The results are shown in FIG. FIG. 7 shows the maximum wind speed, the minimum wind speed, the average wind speed, the wind speed deviation, and the total wind volume for the divided divisions. This value is an average measured three times.
As a result, when the suction port is fully opened, the indoor air is 147 m ³ / h, and about 12% is taken in. At half-open, it is 84 m ³ / h, and about 7.4% is taken up. The indoor air suction effect of the present invention has been confirmed.

<Test 3>
(Air curtain flow and temperature distribution simulation)
FIG. 8 shows the results of simulating the flow and temperature distribution of the air curtain with the air supply unit 1 attached to the fume hood. FIG. 8A is a summer setting, and FIG. 8B is a winter setting.
The setting conditions are 1200 m ³ / h, which is the same amount of outside air supply and draft chamber displacement, indoor set temperature (summer 26 ° C, winter 22 ° C), supply (outside air) temperature (summer 34.6 ° C,). It is set to 0.5 ° C in winter). The suction air volume of the indoor air is calculated by the difference from the exhaust volume, and the exhaust gas is 1800 m ³ / h in the summer and 1920 m ³ / h in the winter, so the suction volume of the indoor air is 600 m ³ / h and 720 m ³ / h, respectively. It is h.

FIG. 8A shows the flow and temperature distribution of the air curtain in summer.
It can be seen that the airflow of the air curtain flowing along the opening surface of the draft chamber is sucked from the opening surface of the draft chamber and exhausted from the exhaust port, and the air-conditioned indoor air is not directly taken in from the opening of the draft chamber. .. The airflow that flows along the worker flows to the worker's feet and flows to the indoor side.
The outside air supplied at 34.6 ° C attracts indoor air at 26 ° C, and the temperature along the front of the worker is 27 ° C near the face, 29 ° C near the thighs, and 30 ° C at the feet. It is flowing inward.
The exhaust of the draft chamber is 30 ° C, and it can be confirmed that the air-conditioned indoor air is mixed with the outside air supplied at 34.6 ° C.

FIG. 8B shows the flow and temperature distribution of the air curtain in winter.
The airflow of the air curtain flowing along the opening surface of the draft chamber is the same as in (a), is sucked from the opening surface of the draft chamber and exhausted from the exhaust port, and the air-conditioned indoor air is the air of the draft chamber. You can see how it is not taken in directly from the opening. The airflow that flows along the worker flows to the worker's feet and flows to the indoor side.
The outside air supplied at 0.5 ° C attracts the indoor air of 22 ° C, and the temperature along the front of the worker is 22 ° C near the face, 16 ° C near the thighs, and 14 ° C at the feet. It is flowing inward.
The exhaust of the draft chamber is 10 ° C, and it can be confirmed that the air-conditioned indoor air is mixed with the outside air supplied at 0.5 ° C.

From this simulation result, it became clear that the supplied outside air was sucked into the draft chamber side and exhausted. In addition, the air curtain reaches the floor and flows. The flow reaching the floor contains outside air, and the amount of air in the air-conditioned room exhausted from the fume hood is assumed to be small.
That is, in the present invention, the airflow sucked into the draft chamber becomes the outside air portion, and the airflow circulating in the room becomes the conditioned air. It has become. The air supply unit is provided with an opening that attracts indoor air, and air is taken in toward the opening of the fume hood, forming an air curtain that is a high-concentration layer of outside air and a high-concentration layer of indoor air. It can be seen that the high-concentration layer of air flows along the operator using the fume hood, is not exposed to the unair-conditioned high-temperature and low-temperature outside air, and the working environment is kept good.
According to the present invention, the loss of air-conditioning energy due to exhaust gas is suppressed, and the working environment is also satisfactorily leaned.

(Comparative test)
FIG. 10 (b) shows the air flow of the fume hood shown in FIG. 10 to which the air curtain generally used at present is not attached. In this fume hood, it is necessary to blow out the outside air whose temperature and humidity are adjusted into the room, and the energy consumption becomes enormous due to the treatment of the outside air. The air flow shown in FIG. 10 (b) shows a test using a fume hood installed in the direction opposite to that of the fume hood shown in FIG. 10 (a).

[Embodiment 2]
This embodiment is an air-conditioning flow in which an air supply unit for introducing outside air into a device requiring exhaust installed in a building such as a laboratory such as a fume hood is provided. FIG. 9 shows an air conditioning flow diagram.
Laboratory A of the building has three fume hoods, and laboratory B has two fume hoods.
An outside air supply system SA is installed in the building, and outside air is taken in from an external controller equipped with power such as a fan and supplied to a draft chamber of a laboratory.
The exhaust system EA exhausts exhaust gas from equipment such as a fume hood from an exhaust treatment device provided with a scrubber or the like provided outdoors.
In the exhaust treatment device, harmful substances contained in the exhaust are trapped or detoxified and released into the atmosphere.
On the other hand, temperature-controlled conditioned air is supplied to the laboratory.
As shown in this embodiment, since the outside air is supplied to a device such as a fume hood, is sucked into the draft chamber and the like, and is discharged, the discharge of the conditioned air is suppressed.
As a result, an environmental load reduction type outside air introduction system has been realized.

1 Air supply unit 11 Housing 12 Outer cylinder 13 Outlet 2 Suction port 3 Suction plate 31 Small hole plate 4 Attracting plate 41 Squeeze opening 5 Inclined plate 6 Blow-out grill 100 Draft chamber 102 Sash opening 103 Work space 106 Rear exhaust passage 110 Outside Intake 111 External intake 112 External airflow 113 Indoor air 114 Corrected airflow 120 Exhaust 122 Apron 123 Work surface 130 Air curtain 131 Internal airflow 132 External airflow 132a Indoor return 140 Exhaust 141 Surface air 142 Bottom air 142a Lower intake air 143 144 Rear exhaust 145 Bottom wind guide

Claims (7)

An air supply unit for a fume hood that forms an air curtain with an air curtain that takes in outside air into the room and blows it out toward the opening of the fume hood as a high-concentration layer of outside air and a high-concentration layer of indoor air .
Equipped with an outer cylinder that communicates with the outside air and an air outlet,
A suction port facing the room is provided between the outer cylinder and the outlet, and a throttle mechanism is provided on the upstream side of the suction port to increase the speed of the outside air. An air supply unit that draws into the unit and creates an air curtain consisting of outside air and indoor air. The air supply unit according to claim 1 , further comprising an outlet grill that regulates the direction of air blown out to the air outlet of the air supply unit. The air supply unit is equipped with a rectifying plate, an attracting plate, a suction port, and a blowout grill from the upstream side in the direction of air flow.
The straightening vane has a large number of pores and
The attract plate is provided with a throttle opening that throttles the airflow that has passed through the straightening vane.
The blowout grill has a louver that regulates the direction of the blown air,
The air supply unit according to claim 1 or 2 . The air supply unit according to any one of claims 1 to 3 , wherein an inclined plate is provided between the suction port and the air outlet. An environmental load reduction type outside air introduction system, wherein the air supply unit according to any one of claims 1 to 4 is arranged above the opening surface of the fume hood. The air curtain blown out from the air supply unit is a multi-layer flow, the opening surface side of the draft chamber is the outside air high concentration layer, and the indoor side is the indoor air high concentration layer.
The environmental load reduction type outside air introduction system according to claim 5 , wherein the surface wind speed of the opening surface of the draft chamber is controlled to 0.4 m / sec or more. The environmental load reduction type outside air introduction system according to claim 6 , wherein the air circulating in the room includes a high concentration layer of indoor air.

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