JPS63251741A - Velocity gradient air curtain device - Google Patents

Abstract

PURPOSE:To prevent fly of a toxic substance to the outside, by a method wherein, in a device where an air flow in a specified direction is formed in a given region, the device is situated in a given region or in a position in the vicinity of the given region, and a velocity of flow is gradually increased or decreased depending upon a utilizing purpose without disturbing a peripheral air flow. CONSTITUTION:A low resistor 18 is situated in a chamber 16 to regulate the velocity of air passing through a push hood 12 or a pull hood 14. The resistor 18 disposed in the push hood 12 is situated such that air velocity is lower below the push hood 12 and an air velocity increases with the increase in the distance from a product 10. In the pull hood 14, the resistor 18 is situated such that the air velocity of income air flow decreases below the pull hood 14 and air flow increases thereabove. The air velocity of the inner air flow, colliding with the product 10, of an air flow discharged through the pull hood 12 can be decreased, and a toxic substance evolved from the product 10 can be prevented from scattering.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a flow velocity gradient air curtain device that can be suitably used in ventilation systems, clean benches, and the like.

(Prior art and its problems) Traditionally, when performing work that generates harmful gases, steam, dust, etc., the workpiece is placed in a unidirectional airflow formed by a ventilation system, etc. , Work in a manner that prevents hazardous substances from being scattered into the surrounding area or exposing workers to hazardous substances. In addition, clean rooms, clean benches, and the like are configured to keep a predetermined area dust-free by allowing dust-free air to flow in a certain direction.

The above-mentioned ventilation system that prevents harmful substances from scattering by placing them in an airflow in a certain direction is a ventilation system in which a bush hood that blows out airflow at a certain speed and a pull hood that sucks in airflow at a certain speed are placed opposite each other. There is a so-called push-pull ventilation system that places a source of harmful substances between the bush hood and the pull hood to isolate harmful substances from the outside air and prevent them from scattering into the return air. The normal safety standards for this push-pull type ventilation system stipulate that the wind speed toward the pull hood be at least 0.3 m/s, and the amount of air sucked in by the pull hood be at least 1.3 times the amount of air blown out from the bush hood. Therefore, products placed between the bush hood and the pull hood will be exposed to fairly strong air currents of 0.3 m/s or more, and for coated products, there may be negative effects such as stripes on the coating film, and organic solvents may There is a point of interest that speeds up the divergence of the loss and increases the loss.

In addition, when handling hazardous substances on a clean bench, dust-free air is forced into the bench, making it impossible to effectively exhaust the hazardous substances emitted inside the bench.
There are problems in that harmful substances blow out from the open surface of the clean bench, exposing workers to harmful substances and deteriorating the working environment. For this reason, it has conventionally been considered undesirable from the standpoint of occupational hygiene to handle hazardous materials inside a clean bench.

Therefore, the present invention was made in view of the above problems, and its purpose is to prevent the adverse effects of airflow on products by installing it in ventilation equipment, clean benches, etc., and to maintain the original characteristics of the device. To provide a flow velocity gradient air curtain device capable of suppressing the scattering of harmful substances to the outside without causing any damage.

(Means for solving problems) The present invention has the following configuration to achieve the above object.

That is, in devices such as push-pull type ventilation equipment, clean benches, clean rooms, etc., in which airflow is formed in a fixed direction within a predetermined area, it is possible to install the device within the predetermined area or near the predetermined area without disturbing the surrounding airflow. It is characterized by gradually increasing or decreasing the flow velocity depending on the purpose of use.

(effect) Next, the effect will be explained.

It is installed in a push-pull type ventilation device, a clean bench, a clean room, etc., and blocks the inside and outside of a predetermined area without disturbing the airflow in a predetermined area such as a bench 20 where an airflow is formed in a fixed direction. As a result, even if harmful substances are used within a predetermined area, the harmful substances will not be scattered around.

(Embodiments) Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[First Embodiment] FIG. 1 is an explanatory diagram showing an embodiment in which the flow velocity gradient air curtain device of the present invention is installed in a push-pull type ventilation device.

In the figure, numeral 10 is a product that generates harmful substances such as paint solvents. Reference numeral 12 represents a bush hood that blows out an air stream at a predetermined speed toward the product 10, and 14 represents a pull hood located opposite the bush hood 12 with the generation source 10 in between.

The bush hood 12 is connected to an air blowing device through a duct behind it, and the pull hood 14 is connected to an air sucking device through a duct.

16 is a chamber provided in front of the opening surface of the bush hood 12 and pull hood 14; 18 is provided within this chamber 16;
2 and a resistor that adjusts the wind speed flowing inside the pull hood 14.

In this embodiment, the resistor 18 disposed on the bush hood 12 is provided so that the wind speed is slow at the bottom of the bush hood 12 and increases as it moves upward away from the product. On the other hand, in the pull hood 14, in accordance with the wind speed distribution of the bush hood 12, the resistance element 18
will be provided.

In this embodiment, the bush hood 1 has the above-described configuration.
Among the airflow blown out from the product 10, the speed of the air on the inside that hits the product 10 can be slowed down, so that the emission of harmful substances generated from the product 10 can be suppressed. In addition, it is possible to prevent the product from being adversely affected by airflow during painting or the like.

Further, with the above-described configuration, by increasing the wind speed at the outer portions of the bush hood 12 and the pull hood 14, the inside and outside of the ventilation system can be completely shut off by the air curtain. This can prevent harmful substances from scattering to the outside.

Incidentally, by setting the suction air volume of the pull hood 14 to be larger than the air volume of the air flow blown out from the bush hood 12, it is possible to suppress the scattering of harmful substances to one worker.

Figure 2 shows a conventional push-pull type ventilation system. In this case, the suction air volume of the bush hood 12 is made larger than the blow-out air volume of the pull hood 14, and the product 10 that generates harmful substances is placed in this air flow to prevent harmful substances from scattering around. In comparison, in this embodiment described above, due to the effect of providing a wind speed gradient in the airflow as shown in the first @, it is possible to reduce the influence of the airflow on the dosage, and it is possible to further enhance the effect of blocking harmful substances.

[Second example] Next, a second example will be described.

Figure 3 shows a conventional vertical flow clean bench6
In the figure, 20 is a bench on which the workpiece is placed, and 22 is a bench 20.
This is a filter installed on the airflow inflow side of the upper part of the air conditioner. 24
is a blower which forces the airflow to pass through the filter 22 and into the bench 20.

The dust-free air that has flowed into the bench 20 is discharged to the outside from the suction port at the bottom of the pliers 20. In this way, bench 20
Dust-free air always flows in a certain direction inside the bench 20, preventing dust-containing air from entering the bench 20 from the outside.
0 clean inside.

FIG. 4 shows an embodiment in which the above-mentioned vertical flow clean bench is provided with a flow velocity gradient air curtain device. 26 in figure
is an air supply duct, and the air flowing from this air supply duct 26 passes through the filter 22 and flows into the bench 2o from the outlet 28 provided at the upper part of the pliers 20 at a uniform wind speed. 3o is a suction port provided at the bottom of the bench 20, and the airflow is exhausted from this suction port 30 to the outside via an exhaust duct 32 at a uniform wind speed.

34a is a blowing chamber provided above the opening surface of the bench 20, from which the dust-free air that has passed through the filter 22 is blown out. 34b is a suction chamber provided at the lower part of the G1 mouth surface of the bench 20. A resistor 36 is provided in the blow-off chamber 34a to adjust the wind speed of the airflow. In addition, a resistor 36 is similarly provided in the suction chamber 34b provided at the lower part of the bench 20, and the suction chamber 3 is adjusted by this resistor 36.
A flow velocity gradient is provided such that the wind velocity on the opening side of the bench 20 of 4b is slow and the wind velocity on the tip side of the suction chamber 34b is high.

As described above, inside the bench 20, the airflow is uniformly blown out from the blowout port 28 toward the suction port 30, but the flow velocity gradient formed between the blowout chamber 34a and the suction chamber 34b is determined by the uniformity inside the bench 20. It is configured to increase the wind speed to a level that completely blocks the inside and outside of the bench 20 in the shortest possible distance without disturbing the flow of air.

Inside the bench 20, the volume of air blown out from the outlet 28 and the volume of air sucked in from the suction port 30 are adjusted separately, and depending on the situation, one of the air volumes is adjusted to be larger than the other. However, this difference in air volume is caused by the difference in air volume between the blowing chamber 34a and the suction chamber 34.
This can be compensated for by adjusting the amount of blowing and suction air.

Normally, the blowout air volume Q and the suction air volume Q inside the bench 2o,
Comparing, it is set as Q1≦Q, and Q, and Q,
The difference flows into the bench 20 from the outside. In this case, the amount of air blown out from the blowing chamber 34a Ql' and the amount of air sucked in from the suction chamber 345 Qff'
Q, '-Q,'>Q, -Q.

In other words, the blowing chamber 3
4 Adjust so as to compensate for the difference between the airflow flc Q- and Q by the difference in the airflow between the airflow volume a and the suction chamber 34b.

In addition, the wind speed of the outlet 28 in the bench 20 is vl,
If the wind speed at the suction port 30 is V, then the wind speed at the boundary between the blow-off chamber 34a and the suction chamber 34b and the bench 20 is set to approximately the same as 1 and V, respectively, so as not to disturb the air flow inside the bench 20. It can be done.

The flow gradient air curtain device is placed on the bench 20 as described above.
By providing the opening surface of the bench 20, it is possible to uniformly supply dust-free air into the clean bench without being affected by external airflow, and to prevent dust-containing air from entering the bench 20 from the outside. can do. Thereby, even if harmful substances are generated within the clean bench, the harmful substances can be captured and exhausted without being released into the outside field.

[Third example] Next, a third example will be described.

FIG. 5 shows an embodiment in which a flow rate gradient air curtain device is installed on a clean bench. In the bench 20 of this embodiment, an airflow outlet 28 is provided at the upper part of the bench 20, and an airflow outlet 30 is provided at the upper part of the bench 20.
is provided on the wall behind the bench 20. A resistor 36 is provided at the outlet 28 and the intake port 30, so that the airflow blown downward from each part of the outlet 28 is directed to the bench 20.
The wind speed blown from the air outlet 28 is given a gradient so that the time required to reach the diagonal line iI\ is constant.

Similarly, a resistor 36 is provided at the suction port 30 to create a flow velocity gradient so that the time from the diagonal positions a, b, c, . . . , 2 to the suction port 30 is constant.

In the figure, 34 is a chamber provided above the opening surface of the bench 20 so as to protrude from the bench 20, and dust-free air flows into this chamber 34 via the filter 22. A resistor 36 is provided in the chamber 34 so that the wind speed increases as the distance from the opening surface increases.

In this embodiment, by providing a flow velocity gradient at the outlet 28 and the inlet 30, the airflow flows as a uniform flow within the bench 20. Also, the bench 20 of the chamber 34
The flow velocity is adjusted to be approximately equal to the flow velocity of the outlet 36 at the boundary with the opening surface.

The flow rate in the outer portion of chamber 34 is set to be sufficient to isolate bench 20 from external airflow.

As a result, the bench 20 can be prevented from being affected by external airflow without disturbing the airflow inside the bench 20, and harmful substances generated inside the bench 20 can be prevented from scattering to the outside. Can be done.

[Fourth Example] Next, a fourth example will be described. Figure 6 shows bench 2
Air outlets are provided on both the top and bottom of the 0.

This is an example in which a flow rate air curtain device is installed on a clean bench with a suction port provided on the rear wall of the bench 20. 28 in figure
a is an upper air outlet provided at the upper part of the bench 20, and 28b is a lower air outlet provided at the lower part of the bench 20. These upper air outlet 28a and lower air outlet 28
b from the air supply ducts 26a and 26b to the filter 22;
Dust-free air flows in through a and 22b. Also, 30a
and 30b are an upper suction port and a lower suction port provided in the upper and lower halves of the rear wall surface of the bench 20. The upper air outlet 28a and the lower air outlet 28b
is provided with a resistor 36 that adjusts the speed of the blowing air so that the time taken from each blowing section to reach the diagonal positions a, b, . Moreover, the upper suction port 30a and the lower suction port 30
A resistor 36 is provided in b so that the time required to reach the suction port from each diagonal position a, b, . . . , 2 is equal.

35a and 35b are an upper chamber and a lower chamber provided opposite to each other at the upper and lower portions of the opening surface of the bench 20. Dust-free air is blown downward from this upper chamber 35a, and this dust-free air is
A flow velocity gradient is provided so that the wind velocity increases as the distance from the opening surface of the bench 20 increases. On the other hand, the structure is such that dust-free air is blown upward from the lower chamber 35b with a flow velocity gradient created by the resistor 36.

In the case of this embodiment as well, the inside and outside of the bench 20 are blocked by the dust-free air blown from the upper chamber 35a and the lower chamber 35b, so that harmful substances generated inside the bench 20 are prevented from scattering to the outside of the bench 20. can do.

Note that the air curtain device provided with a flow velocity gradient is not limited to the above embodiments, and can be similarly used in various devices that form airflow in a fixed direction to block harmful substances and dust-containing air. For example, If the clean room has an airflow of dust-free air in a fixed direction and the area around the dust-free space is open, a flow velocity gradient air curtain device can be installed around the dust-free space to separate the inside and outside of the dust-free space. can be suitably blocked.

In addition, in order to obtain a predetermined flow velocity gradient in each of the above-mentioned embodiments, the inclination and position of the resistor arranged in the chamber, the size of the slit, the interval between the rectifying plates that divide the inside of one duct, etc. Adjusted by adjusting.

(Effects of the Invention) According to the flow velocity gradient air curtain device of the present invention, as described above, by installing it in a device having a predetermined area in which a constant airflow is formed, such as a ventilation device or a clean bench,
Since the predetermined area is completely blocked by the gradient of flow velocity,
Even when a workpiece that generates harmful substances is placed in a predetermined area and a workpiece is placed in the predetermined area, the harmful substances are blocked and do not scatter to the surrounding area, thereby preventing the worker from being exposed to the harmful substances. Also,
By providing a gradient of flow velocity, the airflow can be installed without disturbing the airflow within a predetermined area, which is a remarkable effect.

The present invention has been variously explained above using preferred embodiments, but the present invention is not limited to these embodiments.
Of course, many modifications can be made without departing from the spirit of the invention.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing a first embodiment in which the flow velocity gradient air curtain device according to the present invention is installed in a ventilation system, Fig. 2 is an explanatory diagram showing a conventional ventilation system, and Fig. 3 is a conventional example of a clean bench. FIG. 4 is an explanatory diagram showing a second embodiment in which a flow velocity gradient air curtain device is installed on a clean bench, and FIG.
The figure is an explanatory diagram showing the third embodiment, and FIG. 6 is an explanatory diagram showing the fourth embodiment. 10...Product, 12...Butshu Food. 14...Pull hood, 16...Chamber, 1
8...Resistor, 20...Bench, 22...Filter, 26...Air supply duct. 28...Blowout port, 30...Suction port, 32...
...Exhaust duct, 34...Chamber, 36...
resistor. Figure 1 Figure ' Figure 4 Figure 5

Claims (1)

[Claims] 1. In devices such as push-pull type ventilation equipment, clean benches, clean rooms, etc., in which airflow is formed in a certain direction within a predetermined area, the device is installed in or near the predetermined area without disturbing the surrounding airflow, A flow velocity gradient air curtain device that is characterized by gradually increasing or decreasing the flow velocity depending on the purpose of use.