JP3880191B2 - Fire extinguishing method - Google Patents

Description

注：室内気圧の欄は、火災発生前の初期値と消火ガス放出後の平衡値を示す。
空気流入の欄は、通風取り入れ口の開または閉を示す。
【００２８】
【発明の効果】
本発明の消火方法は、以上に説明したように構成されているので、有害物質取扱い室、ボックスなどの通風排気を停止することなく、室内圧を負圧に維持して消火の際に有害物質などが室外に漏洩するのを防止しながら、火災を確実に消火することが可能となる。また、既設の空調排気装置を改造することなく利用することができ、設備コストをミニマムにできる、消火時の室内の損傷が少なく、復旧が容易であるなどという優れた効果がある。よって本発明は従来の問題点を解消した消火方法として、その工業的価値は極めて大なるものがある。
【図面の簡単な説明】
【図１】本発明の実施形態を説明するための消火装置の機器配置略図。
【図２】ガス消火剤／排気風量比と室内圧との関係を表すグラフ。
【図３】ガス消火剤／排気風量比と消火時間との関係を表すグラフ。
【符号の説明】
１ 有害物質取扱い室、１１ 火源、１２ 火災探知器、２１ 通風空気取り入れ口、３１ 空調排気口、３２ 空調排気装置、４１放出ヘッド、４２ ガス消火剤供給タンク、４３ 供給配管、４４ 流量制御器、４５ 開閉バルブ。[0001]
BACKGROUND OF THE INVENTION
The present invention, which relates to fire extinguishing how a fire in a particular room or box handling hazardous substances hate from leaking to the outside, in particular, fire fighting is a reliable and due to fire and fire fighting about the how as much as possible reduce the damage of the equipment room.
[0002]
[Prior art]
Conventionally, in rooms and boxes that are used for analysis, experiments, storage, etc. of chemical substances and radioactive substances, there are many harmful substances in the internal handling materials, so they are managed as closed spaces so that they do not leak to the outside. Has been. Furthermore, even if there is a slight gap leading to the outside, the indoor air is sucked in by the air-conditioning exhaust system while taking in the ventilation air so that harmful substances do not flow out along with the air flow, and the negative pressure is maintained with respect to the external atmospheric pressure. Facilities are provided to do so. In this way, the hazardous substance handling chamber is normally maintained at a pressure around minus 30 mmH ₂ O. Then, the sucked exhausted air is subjected to a purification process by a predetermined harmful substance removing device, and is considered to be released to the atmosphere.
[0003]
When a fire occurs inside such a hazardous substance handling room, a method using liquefied gas discharge or a method using water spray injection has been put into practical use as a fire extinguishing method. In the former fire extinguishing method by liquefied gas discharge, a mixture of liquefied gas such as halon and carbon dioxide gas and those gases is discharged from the discharge head into the room where the fire has occurred. As a result, the inside of the room becomes positive pressure, and there is a possibility that harmful substances may leak to the outside through the ventilation air intake or other slight gaps.
[0004]
In addition, the latter method using water spray water injection has a stable fire extinguishing performance and is a highly reliable method, but has the following problems.
(1) Depending on the scale of the fire, a large amount of water vapor may be generated, resulting in a positive pressure in the room, and toxic substances may leak along with this water vapor as in the case of liquefied gas fire extinguishing. In this case, even if the ventilating air intake is closed, it is difficult to completely seal the room, and thus the possibility of leakage from a slight gap cannot be solved.
[0005]
(2) Water sprayed during fire extinguishing dissolves harmful substances in the room and new harmful substances generated in the event of a fire, so it is necessary to collect these used water and perform special purification treatment. .
(3) Water supply during fire extinguishing damages the interior of the room, making it difficult to reuse and difficult to recover in a short time.
[0006]
[Problems to be solved by the invention]
The present invention has been made to solve the above-mentioned problems, and without stopping ventilation and exhaust in a hazardous substance handling room or the like, the indoor pressure is maintained at a negative pressure, and harmful substances are present during fire extinguishing. while preventing the leakage of the outdoor provides extinguishing how it becomes possible to reliably extinguish the fire.
[0007]
[Means for Solving the Problems]
The fire extinguishing method of the present invention made to solve the above problem is to exhaust the air with the air conditioning exhaust device while taking in the ventilation air from the ventilation air intake, and maintain the room pressure at a negative pressure of minus 30 mmH ₂ O or less. a hazardous material handling extinguishing method of fire occurring in a room who are, during fire extinguishing, continued operation of the air conditioner exhaust system, and the not close the ventilation air intake, without stopping the ventilation of the room, sky A gas fire extinguisher with an air specific gravity exceeding 1.0 is set so that the discharge amount per unit time is 70% to 80% of the forced exhaust air volume of the room air, and released into the room to maintain the room pressure at a negative pressure. However, it is characterized by extinguishing the fire.
[0008]
And the fire-extinguishing method of this invention can be preferably embodied as the following forms.
(1) A form in which the gas extinguishing agent is a single component gas selected from argon gas, nitrogen gas, carbon dioxide gas and neon gas, or a mixed gas of two or more.
(2) A form in which the digestive agent is discharged from the discharge head disposed in the peripheral portion of the room and exhausted from the air intake of the air conditioning exhaust device disposed in the center of the ceiling.
[0009]
[0010]
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment according to the fire extinguishing method of the present invention will be described with reference to FIGS.
FIG. 1 is a schematic diagram showing a device arrangement model of a fire extinguishing apparatus used in the fire extinguishing method of the present invention . A harmful substance handling room 1 which is a fire extinguishing target is provided with a ventilation air intake 21 and an air conditioning exhaust 31. Thus, the indoor air is exhausted by the air conditioning exhaust device 32 through the air conditioning exhaust port 31 and is always exhausted while being ventilated so that the indoor pressure is maintained at a negative pressure of minus 30 mmH ₂ O or less. Here, the hazardous substance handling room refers to a room that can be used for other general handling such as analysis, experimentation, and storage of hazardous substances such as chemical substances and radioactive substances, including box types, regardless of the form of the room. .
[0012]
In the hazardous substance handling room 1 thus installed, there is a single gas fire extinguishing agent discharge head 41 installed in the room as a fire extinguishing device for extinguishing the fire of the fire source 11 generated in the room. Alternatively, a plurality of gas extinguishing agent supply tanks 42 are arranged on the ceiling or side wall, and for supplying gas extinguishing agent to the discharge head 41 through the supply pipe 43.
[0013]
The most characteristic feature of the present invention is that the supply pipe 43 has a flow rate controller for adjusting the discharge amount of the gas extinguishing agent to a predetermined value in advance so that the indoor pressure does not become a positive pressure when the extinguishing gas is discharged. 44 is provided. In this embodiment, the supply pipe 43 is provided with an open / close valve 45 in series with the flow rate controller 44 and connected to the fire detector 12 provided in the indoor ceiling. Although the opening / closing valve 45 is opened and a predetermined amount of gas extinguishing agent is released into the room, the present invention is not limited to such a form.
[0014]
In the fire extinguisher configured in this way, the negative pressure inside the hazardous substance handling room where ventilation air is taken in and air-conditioning exhaust is performed as described above does not become a positive pressure when the gas extinguisher is released. It is important that the flow rate controller 44 sets the discharge amount of the gas extinguishing agent per unit time at the time of fire extinguishing to a predetermined value smaller than the forced exhaust air volume of the indoor air. It is important that they are coordinated.
[0015]
Here, a relationship between the ratio of the extinguishing gas discharge amount with respect to the exhaust air amount and the indoor atmospheric pressure will be described with reference to FIG. This graph shows that when the indoor pressure is minus 30 mmH ₂ O due to the balance between the intake of ventilation air and the air conditioning exhaust, the horizontal axis is the gas extinguishing agent / exhaust air volume ratio for extinguishing the fire, and the gas fire extinguishing at each ratio. After releasing the agent, the indoor pressure value when the room pressure is balanced again is shown on the vertical axis. If the gas extinguishing agent / exhaust air flow ratio is 80% or less, the room pressure can be kept negative. When 80% is exceeded, the exhaust air volume is relatively insufficient, and it can be seen that the indoor air pressure enters the plus region.
[0016]
In this way, when the amount of gas extinguisher is set so that the gas extinguishing agent / exhaust air flow ratio is 80% or less, the required amount of gas extinguishing agent can be released while the room pressure remains negative. Therefore, it is possible to obtain an advantage that fire extinguishing can be surely performed and harmful substances in the room can be sufficiently prevented from leaking outside.
It was confirmed that such a phenomenon was observed in the same manner regardless of the size of the target indoor volume.
[0017]
In this case, the gas extinguishing agent is a single component gas selected from argon gas, nitrogen gas, carbon dioxide gas and neon gas which is relatively stable with respect to a fire source, or a mixed gas of two or more kinds. Thus, since a heavy gas having an air specific gravity exceeding 1.0, and particularly preferably exceeding 1.3, is difficult to be exhausted by the air conditioning exhaust device, it can be employed as a gas extinguisher suitable for the purpose of the present invention.
[0018]
In addition, when a plurality of the discharge heads for the gas extinguishing agent are arranged in the peripheral part of the room and the air inlet of the air conditioning exhaust device is arranged in the central part of the ceiling, the fire is spread by spreading to the side wall part. In addition to suppressing the expansion, the gas fire extinguisher is less likely to be exhausted in a short-circuit manner, and evenly distributed and filled in the room, covering the fire source 11, so that the bias of the fire extinguishing effect is eliminated. It is particularly preferable because it is effective in a relatively short time.
[0019]
[0020]
Next, an embodiment of the fire extinguishing method of the present invention will be described with reference to the fire extinguishing apparatus. This fire extinguishing method is a fire extinguishing method for a fire generated in the hazardous substance handling chamber 1 in which the indoor pressure is maintained at a negative pressure by taking in the ventilation air and exhausting the air, as described above. The first feature is that the operation of the air conditioning exhaust device 32 is continued during fire extinguishing, the ventilation air intake 21 is not closed, and fire extinguishing is performed without stopping indoor ventilation. Therefore, in addition to applying the air-conditioning / exhaust device 32 which is normally installed as it is, the ventilation air intake 21 may be kept as it is, and it is not necessary to add a closing device, so that the cost of repairing the existing facility is not required.
[0021]
Secondly, in addition to performing such forced exhaust, a gas extinguishing agent with a preset value less than the exhaust air volume per unit time (volume basis) is discharged into the room to reduce the indoor pressure. It is characterized by extinguishing the fire while maintaining the pressure. Specifically, as shown in the examples, a gas fire extinguisher having an air specific gravity exceeding 1.0 is used for a fire generated in a room where the room pressure is maintained lower than minus 30 mmH ₂ O. Then, the discharge amount per unit time is discharged so as to be 70% to 80% of the forced exhaust air volume of the room air.
[0022]
Thus, according to the present invention, it is possible to prevent the room from becoming a positive pressure, there is no risk of harmful substances leaking outside the room, and the fire can be surely extinguished and the gas is extinguished. Since there is no waste water in which indoor harmful substances or new harmful substances generated in the event of a fire are dissolved, there is no damage to the interior of the room due to water injection. The advantage of being able to recover with is obtained.
[0023]
【Example】
In this example, an experimental environment according to FIG. 1 was set. Here, a valve 22 is attached to the ventilating air inlet 21 provided in the experiment box having a capacity of 150 L imitating the hazardous substance handling chamber 1 so that the difference between opening and closing of the ventilating air can be tested. Prior to the experiment, the exhaust device 32 was operated and exhausted to the initial value of the indoor air pressure shown in Table 1 below to maintain the operating conditions of the exhaust device. Then, after igniting n heptane as a fire source in this experimental box, the open / close valve 45 was manually opened, and the release amount of inert gas exemplified in Table 1 below (gas components were N ₂ 52%, Ar 40%, CO 2 the mixed gas) consisting of _{2 8%} released fire extinguishing agents, the time that leads to extinguishing, and were measured equilibrium value of the room pressure.
[0024]
The experimental results are shown in Table 1 below. Here, test NO. 11, 21, and 22 indicate comparative experimental values in a state where the ventilating air intake valve 22 is closed.
According to this result, under the conditions of the present invention in which the extinguishing agent amount / exhaust air volume ratio is 80% or less, it is recognized that the extinguishing agent is extinguished within about 18 to 46 seconds after the extinguishing agent is released, and at the same time, After releasing the fire extinguisher, it was found that although the room pressure increased, the negative pressure state could be maintained and the mimas pressure was shown even when the equilibrium state was reached.
[0025]
Further, when the relationship between the extinguishing agent amount / exhaust air volume ratio and the time required for extinguishing was examined, the results shown in the graph of FIG. 3 were obtained. According to this result, when the ratio of the extinguishing agent / exhaust air volume is small, the absolute amount of the extinguishing agent required for covering the fire source is reduced, so that a tendency to increase the extinguishing time is recognized, especially in the case of 70% or less. However, it was found that the fire extinguishing time exceeds 60 seconds, and there is a risk of fire spread.
[0026]
Also, looking at the relationship between the volume of the hazardous material handling room and the amount of extinguishing agent, if the amount of extinguishing agent released during that time is less than 50% of the room volume on the basis of 60 seconds after the start of release, the extinguishing agent It was found that the absolute amount of was insufficient and it was difficult to make the fire extinguishing time 60 seconds or less. Therefore, the most preferable extinguishing agent release amount is that the releasing amount per 60 seconds after the start of releasing exceeds 50% of the indoor volume, and the extinguishing agent amount / exhaust air volume ratio is in the range of 70 to 80%. It was found that the release amount of
[0027]
[Table 1]

Note: The room pressure column shows the initial value before the fire and the equilibrium value after the fire extinguishing gas is released.
The air inflow column indicates the opening or closing of the ventilation intake.
[0028]
【The invention's effect】
Extinguishing how the present invention, which is configured as described above, hazardous material handling chamber, without stopping the air exhaust element, such as a box, to maintain the chamber pressure to a negative pressure detrimental during firefighting The fire can be surely extinguished while preventing leakage of substances and the like outside the room. In addition, the existing air-conditioning exhaust system can be used without modification, the equipment cost can be minimized, and there is an excellent effect that the room is not damaged during fire extinguishing and can be easily restored. Thus, the present invention is as a fire extinguishing how you solve the conventional problems, its industrial value is made extremely large.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of equipment arrangement of a fire extinguishing apparatus for explaining an embodiment of the present invention.
FIG. 2 is a graph showing a relationship between a gas extinguishing agent / exhaust air flow ratio and a room pressure.
FIG. 3 is a graph showing a relationship between a gas extinguishing agent / exhaust air flow ratio and a fire extinguishing time.
[Explanation of symbols]
1 Hazardous Material Handling Room, 11 Fire Source, 12 Fire Detector, 21 Ventilation Air Intake, 31 Air Conditioning Exhaust, 32 Air Conditioning Exhaust, 41 Release Head, 42 Gas Extinguishing Agent Supply Tank, 43 Supply Piping, 44 Flow Controller 45 Open / close valve.

Claims (3)

A fire extinguishing method for a fire generated in a hazardous substance handling room in which ventilation air is taken in from a ventilation air intake port and exhausted by an air conditioning exhaust system and the room pressure is maintained at a negative pressure of minus 30 mmH ₂ O or less. in the continued operation of the air exhaust system, and without closing the ventilating air intake, without stopping the ventilation of the room, the gas extinguishant air gravity exceeds 1.0, per unit time A fire extinguishing method characterized in that the amount of discharge is set to be 70% to 80% of the forced exhaust air volume of room air, the air is discharged into the room, and the fire is extinguished while maintaining the room pressure at a negative pressure.   The fire extinguishing method according to claim 1, wherein the gas extinguishing agent is a single component gas selected from argon gas, nitrogen gas, carbon dioxide gas and neon gas, or a mixed gas of two or more. The fire extinguishing method according to claim 1 or 2, wherein a digestive agent is discharged from a discharge head disposed in a peripheral portion of the room and exhausted from an intake port of an air conditioning exhaust device disposed in the center of the ceiling.

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