JPH07190431A - Controlled wind velocity automatic alarming apparatus for local exhauster - Google Patents

Abstract

PURPOSE:To provide an apparatus which gives an alarm or adjusts the opening height of a front door when exhaust gas is not appropriately discharged by measuring the opening height of the front door of a local exhaust chamber and the wind velocity within an exhaust duct and judging on the basis of data obtained by the above measurement whether a local exhauster is appropriately discharging the exhaust gas or not. CONSTITUTION:A local exhaust chamber 11 is provided with a front door 12 for opening and closing the local exhaust chamber 11, an opening height measuring system for the front door comprising a potentiometer 17 for measuring the opening height of the front door 12 and an exhaust duct system 19 for exhausting the local exhaust chamber 11. An in-duct wind velocity measuring system comprises an anemometer 20 for measuring the wing velocity in the exhaust duct 19 and the like. A judging function comprising a computer 21 checks whether the difference between suction air volume (X) and discharged gas volume (Y) satisfies preset conditions, wherein the suction air volume (X) is obtained as the product of the width (w) of the front door, the opening opening height (h) of the front door and controlled wind velocity (v) in the vicinity of the front door 12 and the discharged gas volume (Y) is obtained as the product of the section area (S) of the exhaust duct and the wind velocity (V) within the exhaust duct.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control wind speed automatic alarm device for a local exhaust device (draft chamber) used when dealing with substances harmful to the human body such as toxic chemicals and elements constituting compound semiconductor materials. . In the local exhaust system used when handling substances that are harmful to the human body, such as toxic chemicals and elements that make up compound semiconductor materials,
According to regulations such as the Safety and Health Law, it is required to maintain the intake wind speed (control wind speed) near a front door of the local exhaust chamber at a predetermined value in order to prevent harmful gas from leaking into the work space.

[0002]

2. Description of the Related Art In a conventional local exhaust system, a portable anemometer is carried around every time the local exhaust system is used to measure the suction wind speed (control wind speed) near the front door of each local exhaust chamber. , It was determined whether the local exhaust system was exhausted according to the set value, and the opening height of the front door was adjusted within the safe range.

[0003]

However, measuring the control wind speed of the local exhaust system with an anemometer is complicated and has a large error. Especially, as in a semiconductor device manufacturing factory, there are several dozen exhaust systems in one exhaust system. When the local exhaust system is connected, it is necessary to check the exhaust state of the local exhaust chamber each time the use of each local exhaust system is started or periodically. There was a problem that it took a long time to confirm that the exhaust was carried out according to the streets and make adjustments.

According to the present invention, the opening height of the front door of the local exhaust chamber and the wind speed in the exhaust duct are automatically measured at all times, and the measured values are used to determine whether each local exhaust device is properly exhausted. It is an object of the present invention to solve the above problems by making a determination and issuing an alarm if the exhaust is not properly performed, or automatically adjusting the opening height of the front door simultaneously with the alarm.

[0005]

In a control wind speed automatic alarm system for a local exhaust system according to the present invention, a local exhaust chamber measures a front door for opening and closing the local exhaust chamber and an opening height of the front door. A front door opening height measuring system, an exhaust duct for exhausting the local exhaust chamber, an in-duct wind speed measuring system for measuring a wind speed in the exhaust duct, a width w of the front door, an opening height h, and the vicinity of the front door. When the intake air volume, which is the product of the control wind speed v, is X and the exhaust air volume, which is the product of the cross-sectional area S of the exhaust duct and the wind speed V in the exhaust duct, is Y, the difference between X and Y satisfies the preset condition. A configuration having a discrimination function unit for discriminating whether or not is adopted.

In this case, the intake air volume X and the exhaust air volume Y
However, it is possible to employ a configuration including a determination function unit that determines whether or not the condition of X ≦ Y is satisfied.

Further, in this case, it is possible to adopt a construction provided with an interlock mechanism controller for stopping the movement of the front door of the local exhaust chamber when the intake air flow rate X and the exhaust air flow rate Y satisfy preset conditions. .

Further, in this case, it is possible to adopt a construction provided with a potentiometer for measuring the opening height of the front door and an anemometer for measuring the wind speed in the exhaust duct.

Further, in this case, the measurement data of the opening height h of each local exhaust chamber and the wind speed V in the exhaust duct are taken in from the plurality of local exhaust chambers, and the intake air volume X and the exhaust air volume Y of each local exhaust chamber. A configuration including means for monitoring and controlling the relationship can be adopted.

Further, in this case, it is possible to adopt a configuration including means for setting the control priority order of the local exhaust chamber or the restriction order of the opening height of the front door of the local exhaust chamber.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of the principle of a control wind speed automatic warning system for a local exhaust system according to the present invention. In this figure,
Reference numeral 1 is a local exhaust chamber, 2 is a wind speed measurement system of an exhaust duct, 3 is a front door opening height measurement system of a local exhaust device, 4 is an interlock mechanism control unit, 5 is a set value storage unit, 6 is a discrimination function unit, 7
Is an alarm issuing device.

In the local wind exhaust system (draft chamber) control wind speed automatic alarm system of the present invention, the local exhaust chamber 1 is provided.
Is provided with an exhaust duct wind velocity measurement system 2 and a local exhaust device front door opening height measurement system 3, and the measured values of the exhaust duct wind velocity measurement system 2 and the local exhaust device front door aperture height measurement system 3, the control wind velocity v, the set value from the set value storage unit 5 that stores the width of the front door of the local exhaust device and the cross-sectional area S of the exhaust duct are guided to the determination function unit 6, and the determination function unit 6 The result of the determination is guided to the alarm issuing device 7 and the interlock mechanism control unit 4.

In this automatic control wind speed alarm device for the local exhaust system, the intake air volume X, which is the product of the width w of the front door, the opening height h, and the control wind speed v in the vicinity of the front door, the cross-sectional area S of the exhaust duct and the exhaust duct. When comparing with the exhaust air flow rate Y which is the product of the wind speed V inside, the width w of the front door is determined by the local exhaust chamber, and the control wind speed v near the front door is determined in advance by the Safety and Health Law. Is stored in the set value storage unit 5, and the opening height h of the front door is measured by the front door opening height measuring system 3 of the local exhaust device using a potentiometer or the like.

Since the cross-sectional area S of the exhaust duct is determined by the exhaust duct, the value is stored in the set value storage unit 5, and the wind speed V in the exhaust duct is measured by the wind speed measuring system 2 of the exhaust duct. .

Therefore, the intake air volume X and the exhaust air volume Y
The relationship between the opening height h measured by the opening height measuring system 3 of the front door of the local exhaust device and the wind speed measuring system 2 of the exhaust duct is
It can be determined by the exhaust duct opening height h measured by.

When the discriminating function unit 6 discriminates that the relationship between the intake air volume X and the exhaust air volume Y is within a preset dangerous range, a signal is output to the alarm issuing device 7 to issue an alarm. Emit. Further, if necessary, a signal is output to the interlock mechanism control unit 4 so that the local exhaust chamber 1
The front door can be locked to prevent it from opening beyond that position.

At this time, when the condition of the intake air volume X ≦ exhaust air volume Y is satisfied, the pressure in the local exhaust chamber ≧ the pressure in the exhaust duct, and the toxic gas moves toward the exhaust duct due to this pressure difference. , Will not leak into the work space.

FIG. 2 is a diagram for explaining the principle of a control wind speed automatic alarm system for a local exhaust system having a plurality of local exhaust chambers according to the present invention. In this figure, 1 ₁ , 1 ₂ , 1 ₃ , 1 ₄
Is a local exhaust chamber, and 6 is a discrimination function unit.

The principle of the control wind speed automatic alarm system for the local exhaust system according to the present invention has been described above with reference to FIG.
It is also possible to control the opening and closing of the front doors of the plurality of local exhaust chambers by one discriminating function unit.

In this case, one discriminating function unit 6 is provided with a plurality of
Local exhaust chamber 1₁, 1₂, 1₃, 1_FourAre connected.
And each local exhaust chamber 1₁, 1₂, 1₃, 1_FourFrom
Front door opening height h₁, H₂, H₃, H_FourAnd the exhaust duct
Inner Velocity V₁, V₂, V₃, V_FourSignal is the discrimination function unit 6
Is transmitted to each local exhaust chamber in the discrimination function unit 6.
1₁, 1₂, 1 ₃, 1_FourSuction wind set by
The relationship between the air volume and the exhaust air volume is determined and, if necessary, local exhaust
Room 1₁, 1₂, 1₃, 1_FourAlarm signal or interface
Transmit a lock signal.

Under the condition of intake air volume X + ΔX = exhaust air volume Y, ΔX is set to a size corresponding to the toxicity of the gas in each local exhaust chamber, and the opening height of the front door of the local exhaust chamber handling highly toxic gas is set. By making the restriction order stricter than the restriction on the opening height of the front door of the local exhaust chamber that handles less toxic gas, the leakage of the more toxic gas can be completely prevented.

[0022]

EXAMPLES Examples of the present invention will be described below. Figure 3
It is explanatory drawing of the control wind speed automatic warning device of the local exhaust apparatus of one Example of this invention. In this figure, 11 is a local exhaust chamber,
12 is a front door, 13 is a front door stopper, 14 ₁ , 14
₂ is a pulley, 15 is a wire, 16 is a weight, 17 is a potentiometer, 18 is a warning light, 19 is an exhaust duct, 2
0 is an anemometer, 21 is a computer, v is a control wind speed, V is a wind speed in the exhaust duct, h is an opening height of the front door, and S is a cross-sectional area of the duct.

In the control wind speed automatic alarm system for the local exhaust system according to one embodiment of the present invention, the local exhaust chamber 11 is provided with the pulley 1.
By 4 _1, 14 ₂ weight 16 mounted on the tip of the wire 15 subjected to, are adapted to be opened and closed by the front door 12 to lift up and down within a range limited by the front door stopper 13, by this lifting The opening height h of the front door is converted into an electric signal by the potentiometer 17 and transmitted to the computer 21.

The local exhaust chamber 11 is exhausted by the exhaust duct 19, and the wind speed V in the exhaust duct is measured by the anemometer 20, converted into an electric signal and transmitted to the computer 21. . Further, the electric signal of the potentiometer 17 corresponding to the opening height h of the front door and the electric signal corresponding to the wind speed V in the exhaust duct are processed by the computer 21 as described later, and the local exhaust chamber 11 is processed through the opening of the front door 12. The suction air volume X (control wind velocity v x front door width w x front door opening height h) that is sucked into the exhaust air is exhaust air volume Y exhausted by the exhaust duct 19 (exhaust duct cross-sectional area S x wind velocity in the exhaust duct V). ) Is exceeded, an alarm is issued.

FIG. 4 is a system flow chart of a control wind speed automatic warning device for a local exhaust system according to an embodiment of the present invention. The operation of the control wind speed automatic warning system for the local exhaust system according to the embodiment of the present invention will be described with reference to this flowchart. In addition, a, b, c, d ... In this description are shown in FIG.
The reference numerals of the steps are shown.

(A) The wind speed V (m / s) of the exhaust duct is measured by an anemometer and sent to the computer as an electric signal. As the anemometer, various conventionally known anemometers can be used, but for example, “Rion Tr type anemometer (AM-50) (trade name)” (anemometer with an output terminal) can be used. it can.

(B) The cross-sectional area S (m ² ) of the exhaust duct is stored in the computer.

(C) Opening height h of the front door of the local exhaust system
(Cm) is measured with a potentiometer and sent to a computer as an electric signal.

(D) Width w (cm) of the front door of the local exhaust chamber
Is stored in the computer.

(E) The control wind velocity v (m / s) defined by the local exhaust chamber safety and health law is stored in the computer.

(F) In the computer, S × V = Y is calculated from the wind velocity V (m / s) of the exhaust duct in (a) and the cross-sectional area S (m ² ) of the exhaust duct in (b). Then, the exhaust air amount Y (m ³ / h) of the local exhaust chamber is calculated.

(G) The opening height h (cm) of the front door of the local exhaust device of (c) and the width w of the front door of the local exhaust chamber of (d).
(Cm) and the control wind speed v (m / s) prescribed by the local exhaust chamber safety and health law in (e), h × w × v = X
To calculate the suction air flow rate X (m ³ /
Calculate h).

(H) In the computer, the intake air flow rate X (m ³ / h) of the local exhaust chamber and the exhaust air flow rate Y (m ³ / h) of the local exhaust chamber are compared.

(I) When the condition of X≤Y is satisfied, the front door of the local exhaust chamber can be gradually opened.

(K) When the condition of X≤Y is not satisfied, the front door of the local exhaust chamber is locked (j) by the door stopper so that it cannot be opened any more, and the warning light is turned on.

(L) Therefore, by gradually closing the door until the warning light goes out, it is possible to obtain a safe and maximum front door opening height h for the entire system and each draft chamber.

Although it has been described here that the front door is manually opened and closed while visually checking whether the warning light is on or off,
The opening and closing of this front door can be automated. In this case, in the control wind speed automatic alarm device of the local exhaust device shown in FIG. 3, the pulleys 14 ₁ and 14 ₂ to which the wire 15 suspending the front door 12 is applied are driven by the control signal from the computer 21. A mechanism may be provided.

[0038]

As described above, according to the present invention,
It is not necessary to measure the control wind speed with a portable anemometer each time it is used as in the conventional local exhaust system, but the overall height of the system is maintained by measuring the opening height of the front door and the wind speed in the exhaust duct. However, it is possible to automatically secure the control wind speed defined by the Safety and Health Law, and this greatly contributes to the improvement of the operation rate of the local exhaust system.

[Brief description of drawings]

FIG. 1 is a principle explanatory diagram of a control wind speed automatic warning device for a local exhaust system according to the present invention.

FIG. 2 is a principle explanatory diagram of a control wind speed automatic warning device of a local exhaust device having a plurality of local exhaust chambers according to the present invention.

FIG. 3 is an explanatory diagram of a control wind speed automatic warning device for a local exhaust device according to an embodiment of the present invention.

FIG. 4 is a system flowchart of a control wind speed automatic warning device for a local exhaust system according to an embodiment of the present invention.

[Explanation of symbols]

1, 1 ₁ , 1 ₂ , 1 ₃ , 1 ₄ Local exhaust chamber 2 Air velocity measurement system for exhaust duct 3 Front door opening height measurement system for local exhaust system 4 Interlock mechanism control unit 5 Set value storage unit 6 Discrimination function unit 7 Alarm reporting device 11 Local exhaust chamber 12 Front door 13 Front door stopper 14 ₁ , 14 ₂ Pulley 15 Wire 16 Weight 17 Potentiometer 18 Warning light 19 Exhaust duct 20 Anemometer 21 Computer v Control wind speed V Wind speed in exhaust duct h Front Door opening height S Duct cross-sectional area

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location F24F 7/06 C H01L 21/02 Z

Claims (6)

[Claims] 1. A local exhaust chamber, a front door for opening and closing the local exhaust chamber, a front door opening height measuring system for measuring an opening height of the front door, an exhaust duct for exhausting the local exhaust chamber, An in-duct air velocity measuring system for measuring the air velocity in the exhaust duct, and X is a suction air volume, which is a product of the width w of the front door, an opening height h, and a control wind velocity v near the front door, and a cross-sectional area S of the exhaust duct. A local exhaust device comprising a discrimination function unit for discriminating whether or not a difference between X and Y satisfies a preset condition, where Y is an exhaust air volume that is a product of the wind velocity V in the exhaust duct. Control wind speed automatic alarm device. 2. The intake air flow rate X and the exhaust air flow rate Y are X ≦ Y.
The control wind speed automatic warning device for a local exhaust system according to claim 1, further comprising a discrimination function unit for discriminating whether or not the condition is satisfied. 3. An interlock mechanism control unit for stopping the opening / closing operation of the front door of the local exhaust chamber when the intake air flow rate X and the exhaust air flow rate Y satisfy preset conditions. A control wind speed automatic warning device for a local exhaust system according to claim 2. 4. A potentiometer for measuring an opening height of a front door and an anemometer for measuring a wind speed in an exhaust duct are provided, and any one of claims 1 to 3 is provided. Automatic ventilation speed control device for local exhaust system. 5. The measurement data of the opening height h of each local exhaust chamber and the wind speed V in the exhaust duct are taken in from a plurality of local exhaust chambers, and the intake air flow rate X for each local exhaust chamber.
5. A control wind speed automatic warning device for a local exhaust system according to claim 1, further comprising means for monitoring and controlling the relationship between the exhaust air flow rate Y and the exhaust air flow rate Y. 6. The controlled wind speed automatic system according to claim 5, further comprising means for setting a control priority order of the local exhaust chamber or a restriction order of the opening height of the front door of the local exhaust chamber.