JPH06290354A - Sampling type fire detecting device - Google Patents

Abstract

PURPOSE:To provide a sampling type fire detecting device which never issues wrong alarms due to the dust or dirt. CONSTITUTION:In a sampling type fire detecting device consisting of a sampling pipe 1 which absorbs the fire components such as smoke, scorching smell, a smoke detecting part 4 and an absorbing machine 6 which are placed a base end part 2 of the pipe 2, and an alarm board 10 connected to the part 4, a smell detecting part 3 is connected to the board 10 and monitors a monitoring space S that is also monitored by the part 4. Thus, the board 10 decides whether a fire broken out or not based on the output signals of both parts 3 and 4. Then, the board 10 issues an alarm when at least the output signal of the part 3 is set at a level higher than the prescribed value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sampling type fire detection device provided in a semiconductor clean room or the like.

[0002]

2. Description of the Related Art Conventionally, in facilities such as a semiconductor clean room and a computer room for communication lines, where the earliest detection of a fire is required at a very early stage, abnormal smoke caused by a fire is 1000 times more sensitive than an ordinary sensor. There is a fire detection device that uses a high-sensitivity smoke sensor that detects smoke.

This smoke sensor is different from a normal smoke sensor.
Instead of installing it on the ceiling, install a sampling tube with a large number of holes for suction on the ceiling or at the back of the ceiling, and install this smoke sensor and suction device at the base end of the sampling tube to create a dark circle throughout the room. No fire monitoring. The base end is provided under the floor or the like.

When the air in the monitoring space is sucked from the hole of the sampling tube by this suction device and smoke is present in the air, the smoke sensor sends an output signal corresponding to the smoke concentration to a disaster prevention center or the like. The alarm panel provided determines that a fire occurs when this signal exceeds a predetermined level and outputs a fire alarm.

There are various other methods for judging the fire. For example, a value obtained by subtracting a predetermined level from the output signal is added successively, and when the value reaches the predetermined value, it may be judged that the fire has occurred.

On the other hand, as another method of detecting a fire early without using the above-described high-sensitivity smoke sensor, a burning odor that burns before burning smoke, such as a thing, is generated on a ceiling when a fire occurs. There is a method of detecting with an odor sensor installed.

[0007]

Since this sampling type fire detection device always sucks indoor air, it is possible to suck smoke during a fire.
In normal times, even a small amount of dust such as dust existing in the air in the room is sucked. Since the smoke detection method of the smoke sensor provided at the base end of the sampling tube is based on the scattered light method, this dust causes a malfunction. That is, the conventional smoke sensor alone cannot distinguish between smoke and dust, and the malfunction of the smoke sensor causes the alarm panel to give a false alarm.

Therefore, it is an object of the present invention to provide a sampling type fire detection device which does not cause a false alarm due to dust such as dust.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and includes a sampling tube for sucking smoke, a smoke detection section and a suction section provided at the base end of the sampling tube. In a sampling type fire detection device consisting of a fire alarm and a smoke detection unit and an alarm panel connected to the smoke detection unit, a odor detection unit that detects a burning odor sucked from a sampling tube and is connected to the alarm panel is provided. This is to discriminate whether or not there is a fire based on the output signals from the smoke detection section and the odor detection section.The alarm panel should give an alarm action when the output signal from the odor detection section exceeds a predetermined value. It is characterized by.

[0010]

The sampling type fire smoke detector of the present invention is provided with a smoke detector, an odor detector, and a suction device at the base end of the sampling tube, and when a fire occurs in the monitoring space,
Smoke and burnt odor are drawn from the sampling tube. When a fire component such as smoke or charred odor comes to the base end, the odor detecting unit and the smoke detecting unit send an output signal corresponding to the amount of the fire component to the alarm panel. Then, the alarm board performs an alarm operation when the output signal from the odor detector exceeds a predetermined value. Further, when dust is sucked in at normal times, the output signal of the smoke detection unit becomes large, but the output signal of the odor detection unit does not exceed the predetermined value because there is no burning odor to be detected. Therefore, the alarm panel does not operate as an alarm.
False alarms can be prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG.
In the figure, S is a monitoring space such as a clean room of a semiconductor factory, 1 is a sampling pipe provided in the monitoring space S and having a plurality of holes for suction, for monitoring fire in the entire monitoring space S, The end 2 is formed larger than the outer diameter of the sampling tube 1, in which the odor sensor 3 as a odor detector for detecting a burning odor and the scattered light type as a smoke detector for detecting smoke are included. And the smoke sensor 4 are provided.

The odor sensor 3 has a metal semiconductor made of tin oxide or the like and a sensor portion made of a heater.
When odor is adsorbed on tin oxide heated by a heater, its electrical conductivity changes, for example, a semiconductor type sensor.

The sensors 3 and 4 use an analog-to-digital converter that converts an analog amount such as an output voltage or the like, which changes depending on a fire component, into a digital amount, and an output level converted into the digital amount, as an output signal. And a transmitting unit for transmitting the Then, the odor sensor 3 and the smoke sensor 4 send the output signal of the sensor to the alarm panel 10 connected via the transmission line 7 when necessary or periodically.

The odor sensor 3 is provided on the monitoring space side of the base end portion 2.
Is provided, and a dust removing filter 5 is provided between the odor sensor 3 and the smoke sensor 4 to remove some dust such as dust so that it does not enter the smoke sensor 4. . Further, a suction device 6 is provided at the end of the base end 2.
Is provided with a fan, a pump or the like.

Next, the operation of this device will be described. Suction machine 6
By this operation, the air in the monitoring space S is sucked from the plurality of holes of the sampling tube 1, and the air passes through the sampling tube 1 and reaches the base end portion 2.

When a fire occurs in the monitoring space S, smoke and charred odors, which are fire components, are sucked from the holes of the sampling tube 1 and reach the base end portion 2. This base 2
Since its outer diameter is larger than that of the sampling tube 1, the flow of the sucked air is delayed at this point. As a result, the odor sensor 3 can reliably detect the burning odor that is the detection target, and the heating temperature by the heater of the sensor does not decrease.

The air containing the fire component is detected by the odor sensor 3, then passes through the dust removing filter 5 and reaches the smoke sensor 4. The dust removal filter 5 removes some dust and can prevent malfunction of the smoke sensor 4 due to dust to some extent. Further, since the odor such as a burning odor is adsorbed to the dust removing filter 5, by placing the dust removing filter 5 between the odor sensor 3 and the smoke sensor 4, the odor sensor 3 can reliably detect the burning odor that is the detection target. It can detect it. Since the detection principle of the odor sensor 3 is of a semiconductor type, it is not affected by dust.

When smoke reaches the smoke sensor 4, the value of the output signal sent to the alarm panel 10 increases in accordance with the amount of smoke. Similarly, the value of the output signal sent from the odor sensor 3 also increases.

Since the odor sensor is originally installed on the ceiling surface, it is possible to install the odor sensor not on the base end 2 but on the ceiling of the monitoring space S. However, in this case, the odor sensor 3 and the smoke sensor 4 have different detection times of the burning odor and smoke which are the detection targets. That is, the odor sensor 3 provided on the ceiling catches the detection target much earlier than the smoke sensor 4. Therefore, there is a time lag in the value of the output signal. In detail, the value of the output signal of the odor sensor 3 rises immediately with a fire, but that of the smoke sensor 4 is that the smoke that is the detection target is the smoke sensor 4 for a certain time.
It rises after a certain amount of time has passed to reach.

However, the fire judgment of the alarm panel 10 is based on the output signals from the two sensors 3 and 4 which are controlling the fire.
For example, it is performed by comparing the values of the output signals of the two sensors at a certain time. However, if the sensors 3 and 4 are installed at different locations as described above, there is a time lag in the output signal values, so these values cannot be used as they are and an accurate fire judgment is made. I can't.

For this reason, in the present invention, the odor sensor 3 and the smoke sensor 4 are installed together at positions that are substantially close to each other, so that the above problems can be solved and an accurate fire judgment can be made.

Next, an example of the fire judgment of the alarm panel 10 will be described. The alarm panel 10 includes a receiving unit that receives output signals from the sensors 3 and 4, a determining unit that compares the received signal with a predetermined value (level) and the like to determine whether or not there is a fire, and a fire when the fire is determined. And an alarm unit for issuing an alarm.

The alarm panel 10 judges that a fire occurs when the output signal from the odor sensor 3 and the output signal from the smoke sensor 4 each exceed a predetermined value. This is because if a fire is judged only by the output signal from the smoke sensor 4, a false alarm due to dust cannot be prevented. That is, even if the output signal of the smoke sensor 4 becomes a predetermined value or more due to dust, the value of the output signal of the odor sensor 3 does not increase. Therefore, by making the above-described fire determination, a false alarm can be prevented.

Further, as described above, it is not judged as a fire when both of the output signals from the sensors 3 and 4 exceed a predetermined value, but the output signal from the odor sensor 3 alone is judged as a fire. May be.

An embodiment in which the accuracy of the output signal from the odor sensor 3 is improved will be described below. As described above, the odor sensor 3 is formed of tin oxide, and palladium (Pd) and platinum (Pt) are added to the tin oxide.
When a noble metal such as is carried, the detection target changes. For example, palladium is a sensor sensitive to the smell of alcohol, and platinum is a sensor sensitive to CO gas.

Two sensors having different detection targets are used.
The combination is used for the odor sensor 3. For example, a sensor sensitive to burning odor and a sensor sensitive to alcohol odor are used as the odor sensor 3. In this case, when a fire occurs, the value of the output signal of the odor sensor 3 sensitive to the burning odor increases, but naturally, the odor sensor 3 sensitive to the alcohol odor has no alcohol odor to be detected. Therefore, the value of the output signal does not increase.

However, if there is any factor that affects the sensitivity of the odor sensor 3, the value of the output signal of the odor sensor 3 that is sensitive to the alcohol odor also increases.

Therefore, when the output signal of the odor sensor 3 sensitive to the alcohol odor is large, the alarm panel 10 judges that the output signal of the odor sensor 3 sensitive to the burning odor cannot be trusted, and outputs from the smoke sensor 4. The fire may be judged only by the signal. By doing so, the accuracy of the output signal from the odor sensor 3 can be improved.

The smoke sensor and the odor sensor sequentially output the sensor level as an output signal to the alarm board 10, and the alarm board 10 determines the fire based on these output signals. A sensor and an odor sensor may be used to determine whether or not there is a fire. That is, the fire signal may be output when a fire component having a predetermined value or more is detected, instead of sequentially outputting the output signals.

Further, in the above embodiment, the detection part and the alarm part are described as separate components, but they may be integrally formed.

[0031]

Since the present invention is constructed as described above,
False alarms will not occur due to dust such as dust. Also, since the odor sensor and smoke sensor are installed at the same base end,
Since there is no time lag in the value of the output signal to be sent,
Can make accurate fire decisions.

Further, since the odor sensor is provided on the monitoring space side of the base end and the dust removing filter is provided between the odor sensor and the smoke sensor, dust can be removed to some extent by the dust removing filter, and The odor sensor can reliably detect odors such as a burning odor.

Further, since the base end portion is formed larger than the outer diameter of the sampling tube, and the flow of the sucked air is slowed down here, the odor sensor can surely detect the burning odor which is the object of detection, and The heating temperature of the heater does not decrease.

Since the odor detector is composed of two or more odor sensors or gas sensors whose detection targets are different from each other, the accuracy of the output signal from the odor sensor can be improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram of the present invention.

[Explanation of symbols]

 1 Sampling tube 2 Base part 3 Odor detector 4 Smoke detector 5 Dust removal filter 6 Suction machine 7 Transmission line 10 Alarm board S Monitoring space

Claims (6)

[Claims] 1. A sampling-type fire detection device comprising a sampling pipe for sucking smoke, a smoke detection unit and a suction device provided at a base end portion of the sampling pipe, and an alarm panel connected to the smoke detection unit. In the above, a odor detection unit for detecting a burning odor sucked from the sampling tube and connected to the alarm panel is provided, and the alarm panel detects a fire based on the output signals from the smoke detection section and the odor detection section. A sampling type fire detection device for determining whether or not the alarm panel performs an alarm operation at least when the output signal from the odor detection unit exceeds a predetermined value. 2. The sampling type fire detection device according to claim 1, wherein the odor detector is provided at the same base end as the smoke sensor. 3. The sampling according to claim 2, wherein an odor detector is provided on the monitoring space side of the base end, and a dust removal filter is provided between the odor detector and the smoke detector. Fire detector. 4. The sampling type fire detection device according to claim 2, wherein the base end portion is a pipe having a diameter larger than that of the sampling pipe. 5. The sampling type fire detection device according to claim 1, wherein the odor detector comprises two or more odor sensors or gas sensors whose detection targets are different from each other. 6. The sampling fire detecting apparatus according to claim 1, wherein the odor detector is a odor sensor for detecting a burning odor.