JP2756991B2 - Fire alarm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a method for producing a large amount of water vapor, oil mist, etc. in the air, for example, in an Atsushinobu factory of a steel mill, a machining factory, a printing factory, a cement factory, etc. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame alarm device used in a place where the environment in which the air is scattered is inferior, and more particularly to a flame alarm device capable of detecting smoke due to a flame in a monitoring area where such environmental noise is large and distinguishing the flame.

(Prior art) In order to monitor the generation of flame, usually, thermal sensors such as constant temperature type and differential type, smoke detectors such as ionization type, scattered light type and extinction type, constant radiation type, Flame detectors such as flicker type flame detectors are installed on installation surfaces such as ceilings in monitored areas.

As a monitoring area, in addition to a clean environment with little dust such as ordinary office buildings and dwellings, a large amount of water vapor is generated due to water injection and lubrication during processing, such as the Atsushinobu Works of a steel mill. Even in an environment where oil mist is scattered, an environment where fine cutting powder is scattered such as a machining factory, and an environment where a large amount of oil mist and dust soars such as a printing factory and a cement factory, the above various types of Flame detectors are used without any special effort.

(Problems to be Solved by the Invention) The above-mentioned water vapor, oil mist, dust, glowing iron plate, etc., cause the currently used flame detector to generate a flame phenomenon such as heat, smoke or flame generated at the time of flame. Since they are very similar, they correspond to environmental noise factors, which are false alarm factors of the flame detector.

The value, which is the amount of the environmental noise factor, varies greatly during operation and non-operation in, for example, a rolling mill, printing factory, and cement factory, or during processing and non-processing in a machining factory.

If a flame detector is installed in an area where the value of the environmental noise factor is large by the above-described normal method, a false alarm will always occur due to the large value of the environmental noise factor, and the flame monitoring cannot be substantially performed. Becomes

As a countermeasure, it is conceivable to set the flame discriminating criterion of the flame discriminating means provided in the flame detector or the receiver to a level that does not cause a false alarm due to the maximum value of the environmental noise factor. It is performed in general places such as office buildings.

However, this countermeasure cannot detect a flame generated when the value of the environmental noise factor is small in the above-described factory or the like having a large value of the environmental noise factor, and a fatal defect called a false report appears. Can not be adopted.

In addition, since the sensing part of the flame detector is contaminated by water vapor or oil mist, etc., and the sensitivity is reduced, the sensing part must be cleaned frequently.

Further, there is also a problem that the temperature of the electric circuit components of the flame detector rises abnormally due to the high temperature air containing water vapor, thereby shortening the service life.

By the way, Japanese Utility Model Application Laid-Open No. 61-37220 is known as a water filter which is an air purifying device for a clean room in which particulate matter in the air such as smoke, water vapor, oil mist, dust, etc. is maintained at a specified high level. Have been. As a measure for preventing the malfunction of the flame detector due to an environmental noise factor, use of such an air purifying device is considered for the time being.

The water filter passes air in which the particulate matter floats through a diffuser cylinder made of a plastic porous material at the bottom of the water tank, thereby forming extremely fine bubbles. The fine plate containing the particulate matter is further collected and discharged out of the water tank by the perforated plate made of plastic porous material installed in the part, and the air that reaches the upper part of the water tank is clean without particulate matter It is going to be.

As described above, the water filter makes the air in which the particulate matter floats into extremely fine bubbles, traps all the particulate matter in the fine bubbles, and places the finely divided bubbles containing the particulate matter in the perforated plate in the middle of the water tank. It traps and traps not only particulate matter such as water vapor, oil mist, and dust which are relatively coarse environmental noise factors, but also extremely fine particulate matter such as smoke in the micronized bubbles. I have.

Therefore, as in the present invention, a flame alarm device without malfunction is obtained by sufficiently removing particulate matter which is an environmental noise factor and allowing only smoke which is extremely fine particulate matter to reach the flame detector. However, the above-mentioned water filter which is based on the trapping of particulate matter by making the introduced air fine bubbles cannot be dealt with.

The present invention eliminates environmental noise factors, which are relatively coarse particulate matter, and allows only the smoke, which is extremely fine particulate matter, to reach the flame detector, thereby providing a flame alarm device free from false alarms and malfunctions. It is intended to make suggestions.

(Means for Solving the Problems) In order to solve the above problems, according to the first aspect of the present invention, a place where a large amount of environmental noise factors such as water vapor, oil mist, dust or heat adversely affect the flame detection is generated. In the flame alarm device installed in the monitoring area 32, the air in the monitoring area 32 is introduced into a predetermined amount of water in the tank 26, and the air is passed through the water without forming fine bubbles. A water filter device 21 for retaining the environmental noise factor in the water, and a monitoring area
A suction pipe 34 for guiding the air of 32 to the water filter device 21; a scattered light type or dimming type smoke sensing unit 35 connected to the air outlet 22 of the water filter device 21 directly or via a pipe; It is characterized in that it has an introducing means 40 for guiding the air of 32 to the smoke sensing unit 35 via the suction pipe 34 and the water filter device 21.

According to the second aspect of the present invention, there is provided a flame alarm device installed in a monitoring area 32 where a large amount of environmental noise factors such as water vapor, oil mist, dust and heat, which adversely affect flame detection, are generated. Introducing air in the monitoring area 32 into a predetermined amount of water in the tank 26, and allowing the air to pass through the water without forming microbubbles so that the environmental noise factor remains in the water. A water filter device 21 in which a plurality of baffles 28 having air passage holes 27 in water are vertically arranged,
A suction pipe 34 having a plurality of suction ports 33 facing the monitoring area 32 to guide air to the monitoring area 32 to the water filter device 21.
And a scattered light type or extinction type smoke detector connected directly or through a pipe to the air outlet 22 of the water filter device 21.
35, the air suction pipe 34 of the monitoring area 32 and the water filter device 21
And an introduction means 40 for leading the smoke detection unit 35 via the

Furthermore, the invention of claim 2 is characterized in that in the flame alarm device of claim 1 or 2, the water filter device 21 is of a flowing water type.

(Operation) In the invention of claim 1, when the air in the monitored area 32 passes through the water filter device 21, environmental noise factors such as water vapor, oil mist, dust, and heat remain in the water.
Smoke, which is a particle significantly smaller than these environmental noise factors, passes through the water filter device 21 without remaining in the water because the air is not formed into fine bubbles in the water filter device 21, and reaches the smoke sensing unit 35.

As a result, the air reaching the smoke sensing section 35 contains almost no environmental noise factor.

Accordingly, when no flame is generated, the smoke detector 35 does not operate as in the case of a clean environment, and only smoke generated during the flame passes through the water filter device 21 and is detected by the smoke detector 35.

According to the second aspect of the present invention, it is possible to reliably suck the smoke due to the flame at one corner of the wide monitoring area 32 from the plurality of suction ports 33 facing the monitoring area 32 together with the air from the suction pipe 34 into the water filter device 21. .

The sucked air is baffled by the water filter device 21.
The air is divided into a plurality of air masses by a plurality of air passage holes 27 and rises and passes through the water in the tank 26. During this ascent, a plurality of baffles are set up and down
28 extends the path of passage and significantly increases the contact area.

The air mass divided and divided as described above is
While ascending in the water of 26, the wide contact surface allows sufficient contact with water, and all large environmental noise factors remain in the water. Since the air bubbles are not formed into fine bubbles in the filter device 21, they pass through the water without remaining in the water and reach the smoke sensing unit 35.

According to the third aspect of the present invention, since the water filter device 21 is of a flowing water type, environmental noise factors remaining in the water can be efficiently removed from the tank 26 together with the flowing water.
Accumulation of environmental noise factors in the area 21 is prevented, and a good elimination action is always maintained, so that maintenance becomes unnecessary.

(Example) (1) Experiment using a model Water vapor, oil mist,
Environmental noise factors such as dust, use a water filter device,
When water is allowed to pass, cooling action with water, dissolution,
The following experiment was carried out on the assumption that it could be sufficiently removed due to the difference in specific gravity and the like.

(A) Experimental Conditions FIGS. 2 and 3 are schematic front views of the experimental apparatus, and FIG. 4 is a table showing experimental results.

In a room of a laboratory 1 (1.5 m wide, 1 m deep, 1 m high) as a model of a monitoring area, a container 3 containing water 2 and a container 5 containing cutting oil 4 were each heated by an electric heater 6, 7 to generate water vapor and oil mist as an example of environmental noise factors (both containers 3 and 5 were 30 cm wide, 30 cm deep,
It is 20cm deep).

In order to show the environmental noise due to the water vapor and oil mist in the laboratory 1 in this state as an extinction ratio, the extinction ratio was measured to be 50 to 60% / m (FIG. 4).

In the laboratory 1 in this state, a container 8 (width
A flame detection test was carried out for each of the case where the cutting oil 9 contained in 20 cm and the depth of 20 cm) was burned and the case where smoke pieces having a size of 1/2 and 1/25 were burned.

As a water filter device 10, a container 12 containing 10 waters 11
Between the air inlet 13 of the container 12 and the vicinity of the ceiling of the laboratory,
The air outlet 15 of the container 12 is connected to the pipe 16 by a suction pipe 14.
Connected to the sampling chamber 17
Is connected to a suction pump 19 via a pipe 18, and the suction pump 19 is operated to allow the air in the laboratory 1 to pass through the water 11 of the water filter device 10 to reduce the environmental noise in the laboratory 1 The factors are removed, passed through the sampling chamber 17, and then released to the outside air.

In the sampling chamber 17, a scattered light type smoke detector or an ionization type smoke detector was installed as the smoke detector S, and its analog output was converted into a light attenuation rate and shown in FIG.

As an example of an experiment in a large surveillance area, as shown in FIG. 3, a hole 1a is provided in the ceiling of the laboratory 1 and 4.5 m above the hole 1a.
The sampling tube 20 is disposed at the height of the sample tube, a plurality of small holes 20a are provided in the sampling tube 20, and air rising from the hole 1a of the laboratory 1 is sucked into the sampling tube 20 through the small hole 20a. As in the experimental example of FIG. 2, this air is discharged to the outside air by the suction pump 10 through the water filter device 10 and the sampling chamber 17.

The smoke detector S installed in the sampling chamber 17 uses a high-sensitivity scattered light type smoke detector so as to reliably detect the smoke sucked and diluted from the plurality of small holes 20a. Therefore, the paper filter F was provided with an air inlet.

(B) Experimental results (Fig. 4) (a) Without water filter device The scattered light smoke detector shows a 17% / m extinction rate without a water filter device, even without flame generation, without the water filter device 10. ing.

The nominal operating concentration of the scattered light smoke detector is 1 ... 5% / m, 2 ... 10% / m, 3 ... 15% / m. This means that the operation is always performed due to the environmental noise factor, indicating that the flame cannot be determined.

The reason why the extinction rate in the sampling chamber 17 is reduced to 17% / m, while the extinction rate in the laboratory 1 is 50-60% / m, It seems to adhere to.

The extinction rate is higher than 26% / m (scale out) in the case of oil flame, and 23-25% / m, even in the case of 1/25 size, in the case of flame due to smoke fragments, in the case of 1/2 size. High value to scale out.

When the ionization type smoke detector is used, the ratio of the ion current value I ₀ in a state where there is no environmental noise factor to the ion current change value ΔI due to the environmental noise factor or the flame phenomenon, ΔI / I ₀ is
In the case of no flame, the value is 0.06 in both cases of oil flame and smoke flake combustion.

(B) When a water filter device is used The scattered light smoke detector has a low extinction ratio of 2% / m in the absence of a flame, and the water filter device 10 almost eliminates environmental noise factors. It is almost equivalent to a relatively clean monitoring area.

22% / m in the case of oil flame and 23% / m in the case of burning a half size smoke piece. Flame discrimination is possible even with the above three types of smoke detectors. It has become.

The extinction rate is 6% / m when burning a 1/25 size smoke piece. The flame can be distinguished by using one kind of smoke detector, and the sensitivity is good even in the early stage of the flame. It has been found that the use of a smoke detector can provide sufficient flame detection.

In the above measurement values, the extinction ratio in the case of no flame is represented by the noise N, and the extinction ratio at the time of flame occurrence is represented by the S / N ratio of the difficulty of flame discrimination in association with the signal S. Then, as shown in FIG. 4, the value is 11 when the oil flame is fired, and 3 and 11.5 when the smoke is burned.

With a high sensitivity scattered light smoke detector, 0.02
% / M, 0.1% / m for oil flame, S / N ratio of 5, 0.12% / m for Smoke flakes of 1/2 size, S / N ratio of 6 In each case, this indicates that fire determination is possible.

When the ionization type smoke detector is used, there is no change in the ion current in both the case of oil fire and the burning of smoke pieces.
I / I ₀ is 0, indicating that flame determination is not possible.

It is believed that factors such as aerosols that change the ion current that are contained in the combustion products have been removed by the water filter device 10.However, in a fire alarm device using an ionization type smoke detector, Has found that the water filter device 10 cannot be applied.

In each of the above experimental examples, since the oil mist was mixed in the water 11 in the container 12, the oil mist caught by using a water filter device that always allowed the water 11 to flow was adopted. It has been found that maintenance of the water filter device is unnecessary because dust and the like can be automatically discharged.

(C) Summary of experimental results As in the above experimental example, the air in the laboratory 1 is a water filter device.
When passing through the water 11 of 10, environmental noise factors, which are relatively coarse particles, such as water vapor evaporated from the container 3 and oil mist evaporated from the cutting oil of the container 5, sufficiently remain in the water 11. And has been removed by the water filter device 10.

On the other hand, the smoke generated by combustion, which is particles much smaller than the environmental noise factor, is caused by the fact that the air
In 10, since the air bubbles are not formed into fine bubbles, they pass through without reaching the water 11 and reach the smoke detector S.

Therefore, when no flame is generated, the smoke detector S does not operate as in the case of a clean environment, and only smoke due to combustion passes through the water filter device 10 and is detected by the smoke detector S.

In the above experimental example, a scattered light smoke detector was used, and no experiment was performed in the case of using a dimming smoke detector.

However, in the above experimental example, the measured value was converted to a dimming rate, and the result of FIG. 4 was obtained. Therefore, even in a fire alarm device using a dimming smoke detector, the water filter device 10 was not used. It can be expected that a result equivalent to the above-mentioned experimental example will be naturally obtained.

Therefore, based on the above experimental results, the air in the monitored area is guided to the smoke detector through the water filter device, and the smoke detector uses the scattered light type or the extinction type smoke which is called an optical smoke detector. If the detector is used, environmental noise factors having coarse particle diameters such as water vapor, oil mist, and cutting powder can be sufficiently removed by the water filter device 10, and smoke due to combustion, which is particles much smaller than the environmental noise factors, can be used. Has been found to be detected by the smoke detector S without being removed by the water filter device 10.

Thus, if the water filter device 10 having the above structure is used, a steel mill, a machining factory,
In a printing factory, a cement factory, etc., it is possible to perform flame detection without being affected by environmental noise factors and without erroneous reports and unreported reports.

(2) Desirable Configuration Example Based on the above experimental results, a description will be given of a preferable configuration example in which an effective effect can be expected.

 FIG. 1 is a schematic front view of a configuration example.

As shown in FIG. 1, a water filter device 21 is provided in a tank 26 provided with an air outlet 22 and an air inlet 23 at upper and lower positions, respectively, and a water inlet 24 and a water outlet 25 provided at upper and lower positions, respectively. A plurality of baffles 28 each having an air passage hole 27 are provided up and down, so that a constant amount of water 29 is always kept in the tank 26, and the inflow water of the water inlet 24 is supplied by the water supply valve 30. , And water outlet
The 25 drains are adjusted by drain valves 31 respectively.

It is convenient to use, for example, a constant water level water valve provided with a flow switch or the like as the water supply valve 30, and to use, for example, a constant flow rate drain valve as the drain valve 31.

The suction pipe 34 having the suction port 33 extending into the monitoring area 32 is connected to the air inlet 23 of the water filter device 21.

The smoke detector 35 includes a sampling chamber 36 and a scattered light or dimming smoke detector 37 housed therein.

The air outlet 22 of the water filter device 21 is connected to a sampling chamber 36 by a pipe 38, and the outlet of the sampling chamber 36 is
A tube 39 connects to the introduction means 40.

In addition, the water filter device 21 may be provided near the smoke sensing unit 35 or may be provided near the suction port 33.

The introduction means 40 is, for example, a suction pump having a function of guiding the air in the monitored area 32 to the smoke sensing unit 35 via the suction pipe 34 and the water filter device 21.When a suction pump such as a diaphragm type or a hydraulic type is used. Efficient.

The output of the smoke detector 37 is input to the fire receiver 41, and a predetermined alarm operation or fire extinguishing command is output from the fire receiver 41.

With the above configuration example, the air in the monitoring area 32 containing a large amount of environmental noise factors such as water vapor, oil mist, and dust is introduced into the water filter device 21 through the suction pipe 34 by the force of the introduction means 40. When passing through the air passage hole 27 of the baffle plate 28, it becomes a small air bubble and comes into contact with the water 29, and water vapor, oil mist, dust and the like in the air are cleaned and left in the water, and Introduced, the temperature of the air drops.

Therefore, a large amount of environmental noise factors are
In the absence of a fire, the smoke detector 35 is not activated as in the case of a clean monitoring area, and only the smoke from the fire passes through the water filter device 21 and passes through the smoke detector 35. Even in the monitored area 32 where a large amount of environmental noise factors are detected and detected, the trouble of false alarm or unreported fire can be eliminated.

The air purified by the water filter device 21 does not stain the sensing unit of the smoke detector 37, and cleaning of the detection unit is not required.

Further, the air cooled by the water filter device 21 does not raise the temperature of the smoke sensing unit 35, and has an effect of improving durability.

Water always flows into the tank 26 from the water inlet 24 and the water outlet 25
Always drains the water 29 in the tank 26.
The environmental noise factor removed by is automatically and efficiently discharged, and the performance of the water filter device 21 can be kept constant, so that the maintenance work is unnecessary.

The number of suction ports 33 provided in the suction pipe 34 may be appropriately determined according to the size and shape of the monitored area 32.

Although not shown, the water filter device 21 may be a device in which a plurality of tanks are connected, or may be an elongated cylindrical tank or a pipe that can take a long contact distance between air and water, Alternatively, a water curtain system in which air crosses water drops flowing down may be used, and the filter function is further improved by providing multiple water curtains.

The water may be circulated through a filtration device, and the water may be automatically replaced every time a predetermined time elapses, for example, by interlocking a timer device and a water supply / drain valve.

As the baffle 28 in the illustrated example, a punched metal, a net, or the like may be used.

The smoke detector 37 may perform fire discrimination and transmit a fire signal to the fire receiver 41, or may transmit a sensed physical quantity signal to the fire receiver 41 or a repeater (not shown) to transmit the fire signal to the fire receiver 41. Alternatively, a fire determination may be performed in a repeater.

When air is sucked from the plurality of suction ports 33 as shown in the illustrated example, it is desirable to use a high-sensitivity smoke detector that can detect low-concentration smoke.

The sampling chamber 36 becomes unnecessary depending on the type of smoke detector used and the like.

The installation position of the introduction means 40 may be on the primary side (upstream of the air inlet 23) of the water filter device 21 or on the secondary side (downstream of the air outlet 22). In the case of using a sensor, it is preferable to use a secondary side of the smoke detector 35 as shown in the figure in order to prevent the influence of noise generated by the operation of the introducing means 40.

(Effect of the Invention) Since the fire alarm device of the present invention is configured as described above, it has the following effects.

According to the first aspect of the present invention, when the air in the monitored area 32 passes through the water filter device 21, environmental noise factors such as water vapor, oil mist, dust, and heat remain in the water. The smoke, which is much smaller than the particles, passes through the water filter device 21 without remaining in the water because the air is not formed into fine bubbles in the water filter device 21, and reaches the smoke sensing unit 35.

As a result, the air that has reached the smoke detector 35 contains almost no environmental noise factor, and when there is no fire, the smoke detector 35 does not operate as in a clean environment, Only smoke at the time of fire passed through the water filter device 21 and was detected by the smoke detection unit 35, and a highly reliable fire alarm device without false alarms due to environmental noise factors or false alarms at the time of fire was obtained. .

According to the second aspect of the present invention, smoke from a plurality of suction ports 33 facing the monitoring area 32, for example, a fire in one corner of the wide monitoring area 32 and the air are surely removed from the suction pipe 34 through the water filter device.
Can be sucked into 21.

The sucked air is baffled by the water filter device 21.
The air is divided into a plurality of air masses by a plurality of air passage holes 27 and rises and passes through the water in the tank 26. During this ascent, a plurality of baffles are set up and down
28 extends the path of passage and significantly increases the contact area.

The air mass divided and divided as described above is
While ascending in the water of 26, the wide contact surface allows sufficient contact with water, and all large environmental noise factors remain in the water. Since the air bubbles are not formed into fine bubbles in the filter device 21, they pass through the water without remaining in the water and reach the smoke sensing unit 35.

As a result, a fire in, for example, one corner of the wide monitoring area 32 can be reliably detected, and a more reliable fire alarm device can be obtained.

According to the third aspect of the present invention, since the water filter device 21 is of a flowing water type, environmental noise factors can be efficiently removed from the tank 26 together with flowing water, and accumulation of environmental noise factors in the water filter device 21 can be prevented. As a result, a good removal action is always maintained, and maintenance becomes unnecessary.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a front view showing one configuration example of the invention, FIGS. 2 and 3 are front views showing two experimental examples, respectively, and FIG. 4 shows the experimental results. It is a chart. 1 ... laboratory, 1a ... holes 2, 11, 29 ... water 3, 5, 8, 12 ... containers 4, 9 ... cutting oil, 6, 7 ... electric heaters 10, 12 ... water Filter device 13,23… Air inlet 14,34… Suction pipe, 15,22… Air outlet 16,18,38,39… Pipe 17,36… Sampling chamber 19… Suction pump, 20… Sampling tube 20a …… Small hole, 24 …… Water inlet 25 …… Water outlet, 26 …… Tank 27 …… Air passage hole, 28 …… Baffle plate 30 …… Water valve, 31 …… Drain valve 32 …… Monitoring Area, 33 ... Inlet 35 ... Smoke detector, 37 ... Smoke detector 40 ... Introduction means, 41 ... Fire receiver S ... Smoke detector, F ... Filter

Continuation of the front page (72) Inventor Hirotake Yoshiba 4-7-3 Kudanminami, Chiyoda-ku, Tokyo Nomi Disaster Prevention Industry Co., Ltd. (56) References Real opening Sho-56-105196 (JP, U) Real opening Sho-61 −37220 (JP, U) (58) Fields surveyed (Int. Cl. ⁶ , DB name) G08B 17/10-17/117

Claims (3)

(57) [Claims] A flame alarm device installed in a monitoring area where a large amount of environmental noise factors such as water vapor, oil mist, dust, and heat adversely affect flame detection are generated. Introduce the air of the monitoring area into the water of
A water filter device that causes the environmental noise factor to remain in the water by passing the air through the water without being converted into fine bubbles, and a suction pipe that guides air in a monitored area to the water filter device, A scattered light or dimming smoke detector connected directly or through a pipe to the air outlet of the water filter device, and for guiding air in the monitored area to the smoke detector through the suction pipe and the water filter device. And a means for introducing the flame. 2. A flame alarm device installed in a monitoring area where a large amount of environmental noise factors such as water vapor, oil mist, dust and heat, which adversely affect flame detection, are generated. Into a predetermined amount of water in the tank,
In order to allow the air to pass through the water without forming fine bubbles, the environmental noise factor remains in the water, and a plurality of baffles having air passage holes in the water are vertically provided. A water filter device, a suction pipe having a plurality of suction ports facing the monitored region to guide air to the monitored region to the water filter device, and connected directly or via a pipe to an air outlet of the water filter device. A flame alarm device comprising: a scattered light or dimming type smoke detector; and introduction means for guiding air in a monitored area to the smoke detector through a suction pipe and a water filter device. 3. The flame alarm device according to claim 1, wherein the water filter device is of a flowing water type.