JPH0476624B2 - - Google Patents
Info
- Publication number
- JPH0476624B2 JPH0476624B2 JP61304660A JP30466086A JPH0476624B2 JP H0476624 B2 JPH0476624 B2 JP H0476624B2 JP 61304660 A JP61304660 A JP 61304660A JP 30466086 A JP30466086 A JP 30466086A JP H0476624 B2 JPH0476624 B2 JP H0476624B2
- Authority
- JP
- Japan
- Prior art keywords
- particle concentration
- predetermined
- threshold
- alarm
- suspended particles
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000002245 particle Substances 0.000 claims description 190
- 230000001678 irradiating effect Effects 0.000 claims 1
- 239000000779 smoke Substances 0.000 description 26
- 238000001514 detection method Methods 0.000 description 22
- 239000000428 dust Substances 0.000 description 15
- 238000000149 argon plasma sintering Methods 0.000 description 6
- 230000035945 sensitivity Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000002265 prevention Effects 0.000 description 3
- 230000003749 cleanliness Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 1
- 239000000567 combustion gas Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
Description
【発明の詳細な説明】
［産業上の利用分野］
この発明は煙センサに関し、特にクリンルーム
内において操業発塵と区別して初期火災の発生を
正確に検出できる煙センサに関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a smoke sensor, and particularly to a smoke sensor that can accurately detect the occurrence of an initial fire in a clean room, distinguishing it from operational dust.
［従来の技術］
半導体工場のクリンルームは定温、定湿で空気
が高清浄度に保たれた部屋で、その中にはCVD
装置など大電力を使用しかつ燃焼ガスを使用する
製造装置が多数設けられている。このため、クリ
ンルームには消防法で種々の防火設備を設置する
ことが義務づけられており、たとえば煙感知器と
して光電式感知器やイオン化式感知器などが用い
られている。[Conventional technology] A clean room in a semiconductor factory is a room in which the air is kept at a high level of cleanliness at a constant temperature and humidity.
There are many manufacturing devices that use large amounts of electric power and combustion gas. For this reason, the Fire Service Act requires that clean rooms be equipped with various types of fire prevention equipment, and for example, photoelectric detectors, ionization detectors, and the like are used as smoke detectors.
第３図は、従来の、クリンルームに用いられて
いる火災検出装置の構成の一例を示す図である。 FIG. 3 is a diagram showing an example of the configuration of a conventional fire detection device used in a clean room.
初めに、この火災検出装置の構成について説明
する。図において、天井１６に光電式の煙感知器
２３が設けられており、この煙感知器２３は警報
器２５に接続されている。この煙感知器２３につ
いて説明すると、外部へ信号を取出す出力端子を
収納する共通ベース１７上に本体１８が設けられ
ている。本体１８上に複数の開口部１９ａを有す
る暗箱１９が設けられており、この暗箱１９のま
わりに表示灯２０が設けられている。暗箱１９内
には本体１８上に発光素子２１および受光素子２
２が設けれている。 First, the configuration of this fire detection device will be explained. In the figure, a photoelectric smoke detector 23 is provided on the ceiling 16, and this smoke detector 23 is connected to an alarm 25. To explain this smoke detector 23, a main body 18 is provided on a common base 17 that houses an output terminal for outputting a signal to the outside. A dark box 19 having a plurality of openings 19a is provided on the main body 18, and an indicator light 20 is provided around the dark box 19. Inside the dark box 19, a light emitting element 21 and a light receiving element 2 are placed on the main body 18.
2 is provided.
次に、この火災検出装置の動作について説明す
る。クリンルームの火災によつて発生した煙粒子
や粉塵などの浮遊粒子を含む空気が開口部１９ａ
から暗箱１９内に入る。このとき、発光素子２１
からの光は浮遊粒子２４で散乱され、この散乱光
は受光素子２２で受光されて電気信号に変換さ
れ、これによつて火災の発生が検出される。受光
素子２２出力は表示灯１８および共通ベース１７
内の出力端子を介して警報器２５に与えられ、火
災の発生が検出されたことが表示灯１８の点灯に
よつて表示され、警報器２５が警報を発報するこ
とによつて火災の発生を知らせる。 Next, the operation of this fire detection device will be explained. Air containing suspended particles such as smoke particles and dust generated by a fire in the clean room flows through the opening 19a.
Enter dark box 19 from here. At this time, the light emitting element 21
The light from the fire is scattered by the floating particles 24, and this scattered light is received by the light receiving element 22 and converted into an electrical signal, thereby detecting the occurrence of a fire. The light receiving element 22 output is the indicator light 18 and the common base 17
The signal is sent to the alarm device 25 through the output terminal of the device, and the fact that a fire has been detected is indicated by the lighting of the indicator light 18, and the alarm device 25 issues an alarm to indicate that a fire has occurred. Let me know.
［発明が解決しようとする問題点］
ところで、クリンルームには、大量の高清浄度
の空気が常に循環して供給されているため、クリ
ンルーム内で発生した初期火災の発煙は希釈され
てしまうが、従来の煙感知器は、煙粒子に対する
検出感度が低いため、初期火災の発生を正確に検
出することが難しく、火災の規模が大きくなつて
からようやく警報が発報されるという問題点があ
つた。[Problems to be solved by the invention] By the way, a large amount of highly clean air is constantly circulated and supplied to a clean room, so the smoke generated from an initial fire that occurs inside the clean room is diluted. However, because conventional smoke detectors have low detection sensitivity for smoke particles, it is difficult to accurately detect the initial occurrence of a fire, and the problem is that an alarm is only issued after the fire has become large. It was hot.
また、クリンルーム内の空気の清浄度は、製造
装置や作業者などからの操業発塵により時間的、
空間的に変化することが知られているが、従来の
煙感知器では初期火災の発生と操業発塵とを区別
して検出できず、しばしば誤つた警報が発報され
るという問題点もあつた。 In addition, the cleanliness of the air in a clean room may change over time due to operational dust generated from manufacturing equipment or workers.
Although smoke detectors are known to vary spatially, there is a problem in that conventional smoke detectors cannot distinguish between the initial occurrence of a fire and operational dust, and often issue false alarms. .
この発明は上記のような問題点を解消するため
になされたもので、浮遊粒子に対する検出感度が
高く、かつ操業発塵と区別して初期火災の発生を
正確に検出できる簡単な構造で安価な煙センサを
得ることを目的とする。 This invention was made to solve the above-mentioned problems, and it has a simple structure that has high detection sensitivity for floating particles, and can accurately detect the occurrence of an initial fire by distinguishing it from operational dust. The purpose is to obtain a sensor.
［問題点を解決するための手段］
この発明に係る煙センサは、空気移動手段によ
り入口と出口を有する容器内に浮遊粒子を含む空
気を通過させ、光源により容器内の空気を照射
し、受光素子により浮遊粒子からの散乱光を受け
てこれを電気信号に変換し、粒子径しきい値設定
手段により浮遊粒子の粒子径に関する所定粒子径
しきい値を設定し、比較手段により、受光素子出
力を所定粒子径しきい値と比較し、受光素子出力
が所定粒子径しきい値より大きいときにパルスを
発生し、これによつて所定粒子径しきい値より大
きい粒子径の浮遊粒子（以下大径浮遊粒子とい
う）を検出し、期間設定手段により所定期間を設
定し、パルス計数手段により所定期間ごとに上記
パルスの数を計数し、これによつて大径浮遊粒子
の粒子濃度を検出し、粒子濃度しきい値設定手段
により大径浮遊粒子の粒子濃度に関する、所定第
１粒子濃度しきい値およびこれより大きい所定第
２粒子濃度しきい値を設定し、回数設定手段によ
り所定回数を設定し、制御手段により大径浮遊粒
子の粒子濃度を所定第１および第２粒子濃度しき
い値と比較し、この粒子濃度が所定第１粒子濃度
しきい値に一致したとき警報発報手段が第１警報
を発報するように、この粒子濃度が所定第２粒子
濃度しきい値に所定回数一致したとき警報発報手
段が第２警報を発報するようにこの警報発報手段
を制御するようにしたものである。[Means for Solving the Problems] The smoke sensor according to the present invention allows air containing suspended particles to pass through a container having an inlet and an outlet using an air moving means, irradiates the air in the container with a light source, and receives light. The element receives scattered light from suspended particles and converts it into an electrical signal, the particle size threshold setting means sets a predetermined particle size threshold regarding the particle size of the suspended particles, and the comparing means determines the light receiving element output. is compared with a predetermined particle size threshold, and a pulse is generated when the light receiving element output is larger than the predetermined particle size threshold, thereby detecting suspended particles (hereinafter referred to as large particles) with a particle size larger than the predetermined particle size threshold. Detecting large-diameter suspended particles), setting a predetermined period by a period setting means, counting the number of pulses at each predetermined period by a pulse counting means, and thereby detecting the particle concentration of large-diameter suspended particles, The particle concentration threshold setting means sets a predetermined first particle concentration threshold and a predetermined second particle concentration threshold larger than the first particle concentration threshold regarding the particle concentration of large-diameter suspended particles, and the number of times setting means sets a predetermined number of times. , the control means compares the particle concentration of the large-diameter suspended particles with predetermined first and second particle concentration thresholds, and when the particle concentration matches the predetermined first particle concentration threshold, the alarm issuing means operates the first particle concentration threshold. The alarm issuing means is controlled to issue a second alarm when the particle concentration matches a predetermined second particle concentration threshold a predetermined number of times. This is what I did.
［作用］
この発明においては、浮遊粒子の検出部にJIS
B9921に規定されるような光散乱式粒子計数器を
利用しているので、浮遊粒子に対する検出感度が
上がる。[Function] In this invention, the floating particle detection section has JIS
Since it uses a light scattering particle counter as specified in B9921, the detection sensitivity for airborne particles is increased.
また、比較手段により受光素子出力を所定粒子
径しきい値と比較し、受光素子出力が所定粒子径
しきい値より大きいときにパルスを発生すること
によつて、所定粒子径しきい値より大きい粒子径
の浮遊粒子（大径浮遊粒子）を検出する。パルス
計数手段により所定期間ごとに比較手段からのパ
ルスの数を計数することによつて大径浮遊粒子の
粒子濃度を検出し、この粒子濃度を所定第１およ
び第２粒子濃度しきい値と比較し、この粒子濃度
が所定第１粒子濃度しきい値に一致したとき警報
発報手段により第１警報を発報するようにし、こ
の粒子濃度が所定第２粒子濃度しきい値に所定回
数一致したとき警報発報手段により第２警報を発
報するようにしているので、操業発塵と区別して
初期火災の発生を正確に検出することができる。 Further, the comparison means compares the light receiving element output with a predetermined particle size threshold, and generates a pulse when the light receiving element output is larger than the predetermined particle size threshold. Detects suspended particles of particle size (large-diameter suspended particles). Detecting the particle concentration of large-diameter suspended particles by counting the number of pulses from the comparison means at predetermined intervals using the pulse counting means, and comparing this particle concentration with predetermined first and second particle concentration thresholds. When this particle concentration matches a predetermined first particle concentration threshold, the alarm issuing means issues a first alarm, and when this particle concentration matches a predetermined second particle concentration threshold a predetermined number of times. Since the second alarm is issued by the alarm issuing means at the same time, it is possible to accurately detect the occurrence of an initial fire, distinguishing it from operational dust generation.
［実施例］
以下、この発明の実施例を図について説明す
る。[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.
一般に初期火災における浮遊粒子の粒子濃度は
火災に発展する前段階において加速度的に増大し
ていくことが知られており、これに対して操業発
塵における浮遊粒子の粒子濃度は突発的に増加
し、その後クリンルームの機能によつて急激に減
少してしまうものである。この発明は両者の特徴
的な差異に着眼し、JIS B9921に規定されるよう
な光散乱式粒子計数器を利用して浮遊粒子に対す
る検出感度を上げるとともに、操業発塵と区別し
て初期火災の発生を正確に検出できるようにして
いる。 It is generally known that the concentration of suspended particles in an initial fire increases at an accelerating rate before the fire develops, whereas the concentration of suspended particles in operational dust generation increases suddenly. , after which it rapidly decreases due to the functioning of the clean room. This invention focuses on the characteristic differences between the two, and uses a light scattering particle counter as specified in JIS B9921 to increase the detection sensitivity for suspended particles, and to distinguish it from operational dust and detect the occurrence of initial fires. can be detected accurately.
また、空気の清浄度が高いクリンルーム内にお
ける浮遊粒子の粒子径に対する粒子濃度分布特性
と火災状態における浮遊粒子の粒子径に対する粒
子濃度分布特性との間には相似な関係があること
が知られている。したがつて、初期火災の発生の
検出には、それほど微少粒径の浮遊粒子を検出し
なくても粒子径が１〜2μｍ程度の大きい煙粒子
を検出できれば充分で、この発明はこの点も利用
して前記光散乱式粒子計数器と比較してセンサ構
造の簡単化とランプの低輝度点灯による長寿命化
を図つている。 Furthermore, it is known that there is a similar relationship between the particle concentration distribution characteristics of suspended particles in relation to the particle size in a clean room where the air is highly clean and the particle concentration distribution characteristics of suspended particles in relation to the particle size in a fire state. ing. Therefore, in order to detect the occurrence of an initial fire, it is sufficient to be able to detect large smoke particles with a particle size of about 1 to 2 μm without detecting very small suspended particles, and this invention also takes advantage of this point. Compared to the light scattering type particle counter, the sensor structure is simplified and the lamp can be lit at low brightness, resulting in a longer life.
第１図は、この発明の実施例である煙センサの
構成を示す図である。 FIG. 1 is a diagram showing the configuration of a smoke sensor that is an embodiment of the present invention.
初めに、この煙センサの構成について説明す
る。図において、検出セル１は入口１ａと出口１
ｂを有しており、検出セル１に吸引ポンプ２が設
けられている。吸引ポンプ２は入口１ａから検出
セル１内に煙粒子や粉塵などの浮遊粒子を含む空
気を吸入し出口１ｂから空気を排出する。３は検
出セル１内の空気中にある浮遊粒子を示してい
る。また、検出セル１の一方側にランプ４、レン
ズ６ａが設けられており、その他方側に受光素子
５、レンズ６ｂが設けられている。ランプ４から
の光はレンズ６ａを通して検出セル１内の空気に
照射される。受光素子５は浮遊粒子３からの散乱
光をレンズ６ｂを通して受光し、この散乱光を電
気信号に変換する。受光素子５は増幅器７を介し
てコンパレータ９に接続されており、コンパレー
タ９と接地間に直流電源からなる粒子径しきい値
設定器８が接続されている。増幅器７は受光素子
５出力を増幅する。粒子径しきい値設定器８は、
浮遊粒子の粒子径に関する所定粒子径しきい値を
設定する。コンパレータ９は７出力を所定粒子径
しきい値と比較し、受光素子７出力が所定粒子径
しきい値より大きいときにパルスを発生し、これ
によつて所定粒子径しきい値より大きい粒子径の
浮遊粒子（大径浮遊粒子）を検出する。コンパレ
ータ９はパルスカウンタ１０に接続され、計数期
間設定タイマ１１がパルスカウンタ１０に接続さ
れる。計数期間設定タイマ１１は所定計数期間Ｔ
を設定する。パルスカウンタ１０はコンパレータ
９からのパルスの数を所定計数期間Ｔごとに計数
し、これによつて大径浮遊粒子の粒子濃度を検出
する。パルスカウンタ１０は制御装置１２を介し
て警報器１５に接続される。粒子濃度しきい値設
定器１３および回数設定器１４は制御装置１２に
接続される。粒子濃度しきい値設定器１３は、大
径浮遊粒子の粒子濃度に関する、２段階の第１粒
子濃度しきい値および第２粒子濃度しきい値を設
定する。回数設定器１４は所定回数を設定する。
警報器１５は警報を発報する。制御装置１２は、
パルスカウンタ１０出力である大径浮遊粒子の粒
子濃度を第１および第２粒子濃度しきい値と比較
し、大径浮遊粒子の粒子濃度が第１粒子濃度しき
い値に一致したとき警報器１５が第１警報を発報
するように、大径浮遊粒子の粒子濃度が第２粒子
濃度しきい値に上記所定回数一致したとき警報器
１５により第２警報を発報するようにこの警報器
１５を制御する。 First, the configuration of this smoke sensor will be explained. In the figure, a detection cell 1 has an inlet 1a and an outlet 1
b, and the detection cell 1 is provided with a suction pump 2. The suction pump 2 sucks air containing suspended particles such as smoke particles and dust into the detection cell 1 from an inlet 1a, and discharges the air from an outlet 1b. 3 indicates floating particles in the air within the detection cell 1. Further, a lamp 4 and a lens 6a are provided on one side of the detection cell 1, and a light receiving element 5 and a lens 6b are provided on the other side. Light from the lamp 4 is irradiated onto the air within the detection cell 1 through the lens 6a. The light receiving element 5 receives scattered light from the floating particles 3 through a lens 6b, and converts this scattered light into an electrical signal. The light receiving element 5 is connected to a comparator 9 via an amplifier 7, and a particle size threshold setting device 8 made of a DC power source is connected between the comparator 9 and ground. The amplifier 7 amplifies the output of the light receiving element 5. The particle size threshold setting device 8 is
A predetermined particle size threshold for the particle size of suspended particles is set. The comparator 9 compares the 7 output with a predetermined particle size threshold, and generates a pulse when the light receiving element 7 output is larger than the predetermined particle size threshold. Detects suspended particles (large-diameter suspended particles). Comparator 9 is connected to pulse counter 10 , and counting period setting timer 11 is connected to pulse counter 10 . The counting period setting timer 11 has a predetermined counting period T.
Set. The pulse counter 10 counts the number of pulses from the comparator 9 every predetermined counting period T, thereby detecting the particle concentration of large-diameter suspended particles. The pulse counter 10 is connected to an alarm 15 via a control device 12. The particle concentration threshold setter 13 and the number of times setter 14 are connected to the control device 12 . The particle concentration threshold setting device 13 sets a two-stage first particle concentration threshold and a second particle concentration threshold regarding the particle concentration of large-diameter suspended particles. The number of times setter 14 sets a predetermined number of times.
The alarm device 15 issues an alarm. The control device 12 is
The particle concentration of large-diameter suspended particles, which is the output of the pulse counter 10, is compared with the first and second particle concentration thresholds, and when the particle concentration of the large-diameter suspended particles matches the first particle concentration threshold, the alarm 15 is activated. The alarm device 15 is configured to issue a second alarm when the particle concentration of large-diameter suspended particles matches the second particle concentration threshold a predetermined number of times. control.
次に、この煙センサの動作について説明する。
クリンルーム内の煙粒子や粉塵などの浮遊粒子を
含む空気は吸引ポンプ２によつて入口１ａから細
い気流となつて検出セル１内に入り、空気は出口
１ｂから排出される。このとき、この細い気流に
ランプ４からの光がレンズ６ａを通して照射され
る。気流中の浮遊粒子３はランプ４からの光を散
乱し、この散乱光は受光素子５によつて受光され
る。受光素子５は散乱光を電気信号に変換し、こ
の電気信号は増幅器７に与えられる。増幅器７は
受光素子５出力を増幅し、増幅器７出力はコンパ
レータ９に与えられる。コンパレータ９は、増幅
器７出力を粒子径しきい値設定器８で設定され
た、たとえば粒子径1.5μｍの粒子径しきい値と比
較し、増幅器７出力がこの粒子径しきい値より大
きいときにパルスを出力し、これによつて浮遊粒
子のうちの大径浮遊粒子を検出する。コンパレー
タ９出力はパルスカウンタ１０に与えられる。パ
ルスカウンタ１０は、計数期間設定タイマ１１に
より設定された計数期間Ｔごとにコンパレータ９
からのパルスの数を計数し、これによつて大径浮
遊粒子の粒子濃度（個／単位体積）を検出する。
パルスカウンタ１０出力は制御装置１２に与えら
れる。制御装置１２は、パルスカウンタ１０出力
である大径浮遊粒子の粒子濃度を粒子濃度しきい
値設定器１３で設定された第１および第２粒子濃
度しきい値と比較し、この粒子濃度が第１粒子濃
度しきい値に一致したとき制御装置１２出力によ
り警報器１５から第１警報（たとえば、“ダスト
が多いのでチエツクして下さい”）を発報し、こ
の粒子濃度が第２粒子濃度しきい値に回数設定器
１４で設定された所定回数、たとえば３回一致し
たときに制御装置１２出力により警報器１５が第
２警報（たとえば、“火災です。避難して下さ
い”）を発報する。 Next, the operation of this smoke sensor will be explained.
Air containing suspended particles such as smoke particles and dust in the clean room enters the detection cell 1 as a thin air stream from the inlet 1a by the suction pump 2, and is discharged from the outlet 1b. At this time, the light from the lamp 4 is irradiated onto this thin airflow through the lens 6a. Floating particles 3 in the airflow scatter the light from the lamp 4, and this scattered light is received by the light receiving element 5. The light receiving element 5 converts the scattered light into an electrical signal, and this electrical signal is provided to the amplifier 7. The amplifier 7 amplifies the output of the light receiving element 5, and the output of the amplifier 7 is given to the comparator 9. The comparator 9 compares the output of the amplifier 7 with a particle size threshold set by the particle size threshold setter 8, for example, a particle size of 1.5 μm, and when the output of the amplifier 7 is larger than this particle size threshold, A pulse is output, thereby detecting large-diameter suspended particles among the suspended particles. The comparator 9 output is given to a pulse counter 10. The pulse counter 10 outputs a comparator 9 every counting period T set by the counting period setting timer 11.
The number of pulses is counted, and the particle concentration (pieces/unit volume) of large-diameter suspended particles is thereby detected.
The pulse counter 10 output is given to the control device 12. The control device 12 compares the particle concentration of large-diameter suspended particles, which is the output of the pulse counter 10, with first and second particle concentration thresholds set by the particle concentration threshold setting device 13, and determines whether this particle concentration is the first particle concentration. 1 When the particle concentration reaches the threshold value, the controller 12 output causes the alarm 15 to issue the first alarm (for example, "There is a lot of dust, so please check"), and this particle concentration becomes the second particle concentration. When the threshold value matches the predetermined number of times set by the number setter 14, for example three times, the alarm 15 issues a second alarm (for example, "There is a fire. Please evacuate") by the output of the control device 12. .
次に、第２図を用いて第１警報、第２警報の発
報動作の例について説明する。 Next, an example of the operation of issuing the first alarm and the second alarm will be explained using FIG.
第２図において、横軸は時間を、縦軸は、たと
えば６秒の計数期間Ｔごとに検出されたクリンル
ーム内の空気中の径型浮遊粒子の粒子濃度を示し
ている。時間０〜t6では粒子濃度がC1〜C6と変化
して粒子濃度が突発的に増加した後急激に減少し
ており、このような変化形態は操業発塵によるも
のである。この場合には、M2点、M3点、で粒子
濃度が、たとえば１×104個／フイート3の第１粒
子濃度しきい値CTH1に一致し、これらの点に対応
する各時点で第１警報が発報される。時間t8〜t13
では粒子濃度はC9〜C13と変化して粒子濃度が加
速度的に増加しており、このような変化形態は初
期火災の発生によるものである。この場合には、
M10点、M11点、M12点、M13点で粒子濃度が第
１粒子濃度しきい値CTH1に一致し、これらの各点
に対応する各時点で第１警報が発報され、N11
点、N12点、N13点で粒子濃度が、たとえば４×
104個／フイート3の第２粒子濃度しきい値CTH2に
一致し、粒子濃度が第２粒子濃度しきい値CTH2に
３回目に一致するN13点に対応する時点で第２警
報が発報される。 In FIG. 2, the horizontal axis shows time, and the vertical axis shows the particle concentration of diameter-shaped suspended particles in the air in the clean room detected every counting period T of, for example, 6 seconds. From time 0 to t6 , the particle concentration changes from C1 to C6 , the particle concentration suddenly increases, and then rapidly decreases, and this type of change is due to operational dust generation. In this case, the particle concentration at points M 2 and M 3 coincides with the first particle concentration threshold C TH1 of, for example, 1 × 10 4 particles/foot 3 , and at each time point corresponding to these points, The first alarm is issued. Time t 8 ~ t 13
In this case, the particle concentration changes from C9 to C13 , and the particle concentration increases at an accelerating rate, and this type of change is due to the occurrence of the initial fire. In this case,
The particle concentration matches the first particle concentration threshold C TH1 at M 10 points, M 11 points, M 12 points, and M 13 points, and the first alarm is issued at each point corresponding to each of these points, N11
For example, the particle concentration at the point, N12 point, and N13 point is 4×
10 The second particle concentration threshold C TH2 of 4 particles/foot 3 is met, and the second alarm is activated at the point corresponding to the N 13 point where the particle concentration matches the second particle concentration threshold C TH2 for the third time. Reported.
このように、浮遊粒子検出部にJIS B9921に規
定されるような光散乱式粒子計数器を利用するこ
とによつて浮遊粒子に対する検出感度を従来の煙
感知器に比べて上げることができる。また、浮遊
粒子のうち大径浮遊粒子を検出するようにしてい
るので、上記光散乱式粒子計数器の場合よりラン
プ４の低輝度点灯による長寿命化が可能となりそ
の寿命を長くすることができ、たとえば点灯寿命
が10000時間程度の白熱ランプを用いることがで
きる。また、大径浮遊粒子を検出することによつ
て煙センサの構造も簡単化することができ、煙セ
ンサを安価に製造することができる。また、大径
浮遊粒子の粒子濃度を第１および第２粒子濃度し
きい値と比較し、この粒子濃度が第１粒子濃度し
きい値に一致したとき第１警報を発報し、この粒
子濃度が第２粒子濃度しきい値に３回一致したと
き第２警報を発報するようにしているので、操業
発塵と区別して初期火災の発生を正確に検出する
ことが可能となる。 In this way, by using a light scattering particle counter as specified in JIS B9921 in the suspended particle detection section, the detection sensitivity for suspended particles can be increased compared to conventional smoke detectors. In addition, since large-diameter suspended particles among suspended particles are detected, it is possible to extend the life of the lamp 4 by lighting it at a lower brightness than in the case of the light scattering type particle counter described above. For example, an incandescent lamp with a lighting life of about 10,000 hours can be used. Furthermore, by detecting large-diameter suspended particles, the structure of the smoke sensor can be simplified, and the smoke sensor can be manufactured at low cost. In addition, the particle concentration of large-diameter suspended particles is compared with the first and second particle concentration thresholds, and when this particle concentration matches the first particle concentration threshold, a first alarm is issued, and the particle concentration Since the second alarm is issued when the particle concentration matches the second particle concentration threshold three times, it is possible to accurately detect the occurrence of an initial fire, distinguishing it from operational dust generation.
なお、上記実施例では、計数期間Ｔを６秒、第
１粒子濃度しきい値を１×104個／フイート3、第
２粒子濃度しきい値を４×104個／フイート3に設
定する場合について示したが、この発明はこれに
限定されるものではなく、クリンルームの特性
（たとえば、換気回路、清浄時の粒子濃度など）
に合わせて、計数期間Ｔなどを適当に選べばよ
い。また、上記実施例では、大径浮遊粒子の粒子
濃度が第２粒子濃度しきい値に３回一致したとき
第２警報を発報する場合について示したが、第２
粒子濃度しきい値に３回より大きい回数一致した
とき第２警報を発報するようにして、火災警報の
誤報確率をさらに少なくすることもできる。 In the above embodiment, the counting period T is set to 6 seconds, the first particle concentration threshold is set to 1×10 4 particles/ft 3 , and the second particle concentration threshold is set to 4×10 4 particles/ft 3 . Although shown for the case, the invention is not limited thereto, and the characteristics of the clean room (e.g. ventilation circuit, particle concentration during cleaning, etc.)
The counting period T etc. may be appropriately selected according to the above. In addition, in the above embodiment, the second alarm is issued when the particle concentration of large-diameter suspended particles matches the second particle concentration threshold three times.
It is also possible to further reduce the probability of false fire alarms by issuing a second alarm when the particle concentration threshold is met a number of times greater than three times.
また、上記実施例では煙センサをクリンルーム
の防火用として用いる場合について示したが、こ
の発明は他の設備の防火用としても用いることが
でき、また粉塵の多い空気や排気ガスなどの単な
る粉塵量の測定用として用いることもできる。 In addition, although the above embodiment shows a case in which the smoke sensor is used for fire prevention in a clean room, the present invention can also be used for fire prevention in other equipment, and can also be used for simple dust detection such as dusty air or exhaust gas. It can also be used for measuring quantities.
［発明の効果］
以上のようにこの発明によれば、浮遊粒子検出
部にJIS B9921に規定されるような光散乱式粒子
計数器を利用し、浮遊粒子のうち大径浮遊粒子を
検出するようにし、大径浮遊粒子の粒子濃度が所
定第１粒子濃度しきい値に一致したとき第１警報
を発報するようにし、この粒子濃度が所定第２粒
子濃度しきい値に所定回数一致したとき第２警報
を発報するようにしているので、浮遊粒子に対す
る検出感度が高く、かつ操業発塵と区別して初期
火災の発生を正確に検出できる簡単な構造で安価
な煙センサを得ることができる。[Effects of the Invention] As described above, according to the present invention, a light scattering particle counter as specified in JIS B9921 is used in the suspended particle detection unit to detect large-diameter suspended particles among suspended particles. and when the particle concentration of large-diameter suspended particles matches a predetermined first particle concentration threshold, the first alarm is issued, and when this particle concentration matches the predetermined second particle concentration threshold a predetermined number of times. Since the second alarm is issued, it is possible to obtain an inexpensive smoke sensor with a simple structure that has high detection sensitivity for suspended particles and can accurately detect the occurrence of an initial fire by distinguishing it from operational dust. .
第１図は、この発明の実施例である煙センサの
構成を示す図である。第２図は、第１図の煙セン
サにおける第１警報、第２警報の発報動作を説明
するための図である。第３図は、従来の火災検出
装置の構成の一例を示す図である。
図において、１は検出セル、１ａは入口、１ｂ
は出口、２は吸引ポンプ、３は浮遊粒子、４はラ
ンプ、５は受光素子、６ａ，６ｂはレンズ、７は
増幅器、８は粒子径しきい値設定器、９はコンパ
レータ、１０はパルスカウンタ、１１は計数期間
設定タイマ、１２は制御装置、１３は粒子濃度し
きい値設定器、１４は回数設定器、１５は警報器
である。なお、各図中同一符号は同一または相当
部分を示す。
FIG. 1 is a diagram showing the configuration of a smoke sensor that is an embodiment of the present invention. FIG. 2 is a diagram for explaining the operation of issuing a first alarm and a second alarm in the smoke sensor of FIG. 1. FIG. 3 is a diagram showing an example of the configuration of a conventional fire detection device. In the figure, 1 is a detection cell, 1a is an entrance, 1b
is an outlet, 2 is a suction pump, 3 is floating particles, 4 is a lamp, 5 is a light receiving element, 6a, 6b are lenses, 7 is an amplifier, 8 is a particle size threshold setter, 9 is a comparator, 10 is a pulse counter , 11 is a counting period setting timer, 12 is a control device, 13 is a particle concentration threshold setting device, 14 is a frequency setting device, and 15 is an alarm device. Note that the same reference numerals in each figure indicate the same or corresponding parts.
Claims (1)
空気移動手段と、 前記容器内の前記空気を照射する光源と、 前記浮遊粒子からの散乱光を受けてこれを電気
信号に変換する受光素子と、 前記浮遊粒子の粒子径に関する所定粒子径しき
い値を設定する粒子径しきい値設定手段と、 前記受光素子出力を前記所定粒子径しきい値と
比較し、該受光素子出力が該所定粒子径しきい値
より大きいときにパルスを発生し、これによつて
前記所定粒子径しきい値より大きい粒子径の前記
浮遊粒子（以下大径浮遊粒子という）を検出する
比較手段と、 所定期間を設定する期間設定手段と、 前記所定期間ごとに前記パルスの数を計数し、
これによつて前記大径浮遊粒子の粒子濃度を検出
するパルス計数手段と、 前記粒子濃度に関する、所定第１粒子濃度しき
い値およびこれより大きい所定第２粒子濃度しき
い値を設定する粒子濃度しきい値設定手段と、 所定回数を設定する回数設定手段と、 警報を発報する警報発報手段と、 前記粒子濃度を前記所定第１および第２粒子濃
度しきい値と比較し、該粒子濃度が該所定第１粒
子濃度しきい値に一致したとき前記警報発報手段
が第１警報を発報するように、該粒子濃度が該所
定第２粒子濃度しきい値に前記所定回数一致した
とき前記警報発報手段が第２警報を発報するよう
に該警報発報手段を制御する制御手段とを備えた
煙センサ。[Scope of Claims] 1. A container having an inlet and an outlet, an air moving means for passing air containing suspended particles in the container, a light source for irradiating the air in the container, and scattering from the suspended particles. a light receiving element that receives light and converts it into an electrical signal; a particle size threshold setting means that sets a predetermined particle size threshold regarding the particle size of the suspended particles; A pulse is generated when the light-receiving element output is larger than the predetermined particle size threshold when compared with a threshold value, and thereby the suspended particles (hereinafter referred to as large diameter particles) whose particle size is larger than the predetermined particle size threshold are generated. a period setting means for setting a predetermined period; and a period setting means for counting the number of pulses for each predetermined period;
pulse counting means for detecting the particle concentration of the large-diameter suspended particles by this; and a particle concentration for setting a predetermined first particle concentration threshold and a predetermined second particle concentration threshold larger than the predetermined first particle concentration threshold with respect to the particle concentration. threshold setting means; number setting means for setting a predetermined number of times; alarm issuing means for issuing an alarm; and comparing the particle concentration with the predetermined first and second particle concentration thresholds, The particle concentration matches the predetermined second particle concentration threshold the predetermined number of times, such that the alarm issuing means issues a first alarm when the concentration matches the predetermined first particle concentration threshold. and control means for controlling the alarm issuing means so that the alarm issuing means issues a second alarm when the alarm issuing means issues a second alarm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61304660A JPS63157035A (en) | 1986-12-19 | 1986-12-19 | Smoke sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61304660A JPS63157035A (en) | 1986-12-19 | 1986-12-19 | Smoke sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63157035A JPS63157035A (en) | 1988-06-30 |
| JPH0476624B2 true JPH0476624B2 (en) | 1992-12-04 |
Family
ID=17935696
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61304660A Granted JPS63157035A (en) | 1986-12-19 | 1986-12-19 | Smoke sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63157035A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2740262B2 (en) * | 1989-05-16 | 1998-04-15 | 消防庁長官 | Particle size measurement smoke detector |
| JP3714926B2 (en) * | 2002-08-22 | 2005-11-09 | ホーチキ株式会社 | Sampling tube smoke detector |
| JP5420437B2 (en) * | 2010-01-19 | 2014-02-19 | 株式会社オプティコン | Powder detector |
-
1986
- 1986-12-19 JP JP61304660A patent/JPS63157035A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63157035A (en) | 1988-06-30 |
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