HK1139348B - Device and method for fire-prevention and for extinguishing a fire that has broken out in an enclosed area - Google Patents

Description

The present invention relates to an inertisation process for fire prevention and fire suppression in a confined space, in particular a laboratory space, whereby fresh air is supplied to the room atmosphere in a regular manner as exhaust air and exhaust air is discharged from the room atmosphere in a regular manner, and whereby, in the event of a fire or to prevent a fire, a gaseous extinguishing agent is supplied to the room atmosphere under normal conditions as exhaust air.

Printed form DE 10 2005 023 101 A1 refers to a method of introducing an inert gas into a confined space by means of which the compressed inert gas is directed at a rate of approximately constant flow into the extinguishing or protecting area.

The printed form DE 102 49 126 A1 concerns a process for producing an oxygen-free atmosphere in a room by pumping out oxygenated air and replacing it with a low-oxygen gas, by filtering out the oxygen content of the room or ambient air and releasing it into the atmosphere and pumping the filtered, mostly oxygen-free air into the room to be intercepted.

The form DE 44 13 074 A1 concerns a process for inerting reactors.

The printed form US 2001/0029750 A1 relates to a specific inert gas composition for breathing and a fire prevention and fire-extinguishing system with such a composition.

The printed form EP 1 683 548 A1 concerns an inerting procedure to prevent fire or explosion in a first enclosed protection area by reducing the sulphur content of the protection area against ambient air to a basic inerting level.

The US 2003/0226669 A1 is a similar inerting process.

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In order to meet these requirements, it is necessary, in particular in large-volume spaces such as laboratory spaces, production spaces or warehouses, that, where necessary, a sufficient amount of inert gas can be introduced into the ambient atmosphere of the enclosed space as quickly as possible, i.e. within the 60 seconds required by the VdS Directive.

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Due to the requirement that inert gas extinguishing technology requires that an oxygen displacement gas be introduced into the enclosed space as quickly as possible at least at the beginning of the flood to allow for safe and effective fire fighting, structural pressure relief is essential for the enclosed space to prevent damage to at least parts of the enclosure. Such pressure relief is usually achieved by the installation of pressure relief valves. The task of pressure relief valves instead of closing is to protect the enclosed space pressure relief from damage, even if there are openings inside the enclosure, such as the sudden introduction of a solvent that causes a sudden release of gas, which can be prevented by the excess pressure. It is therefore known that a mechanical discharge can be provided relatively quickly in the case of a mechanical overloading of the enclosure.

The disadvantage of such mechanical pressure relief is that the pressure relief area to be taken into account must be estimated at the planning stage before the enclosed space is completed. The dimensions of the pressure relief valves to be installed must also be determined at the planning stage. In particular, the effective air or gas flow area to be provided by the pressure relief valve must be estimated in advance.

The design and dimensioning of the pressure relief valves used is often based on the assumption of a theoretical excess pressure in the enclosed space. For reasons of design reliability, this theoretical value often has to be supplemented with a more or less generous safety premium to take account of extra-planned pressure loads.

In addition, a closed space already equipped with a conventional inert gas fire extinguishing system can often only be modified or extended to a limited extent.

The previously known approach to providing pressure relief does not allow, or only requires greater design effort, that in a room already equipped with a conventional inert gas fire extinguisher and a conventional pressure relief system, the atmosphere in the room maintains a deliberately adjusted artificial pressure ratio during the flood with inert gas before flooding. This requirement should be taken into account, for example, in laboratory rooms where the pressure is permanently reduced in relation to the ambient pressure, in order to prevent, for example, the escape of particles, substances, viruses, etc. dangerous to health by means of the pressure relief pressure applied inside the room. This requirement would be used to provide permanent pressure relief when a pressure relief mechanism is required to prevent the failure of the pressure relief mechanism.

On the basis of this problem, the present invention is intended to develop a fire-extinguishing system based on the principle of inertisation and a fire-extinguishing process of the type described at the outset, in such a way that, for a closed room, in particular a laboratory room in which a permanent low pressure is applied, the pressure relief required in the event of a flood of inert gas is decoupled over the largest possible area from the size of the room and the volume of the room, while allowing the pressure relief to be maintained even when inert gas is introduced rapidly in the room, so as to prevent the air pressure applied in the room from being dissolved even during the flood of the insulated room by any dangerous substances which may be present in the room, for example, particulate matter, etc. The present invention is intended to solve a problem which may be solved by means of the present invention.

This task is solved for the process by the subject-matter of the independent patent claim 1 and for the device by the subject-matter of the ancillary patent claim 11, with the subclaims indicating beneficial training in the process or device.

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The method of the invention provides in particular that, in the process of the type described at the outset, at least at the stage of the sudden introduction of the extinguishing agent into the atmosphere, the pressure present in the atmosphere is measured and the pressure measured is compared with a specified maximum pressure value, and then, depending on the result of the comparison, a pressure drop is generated in the enclosed space so that the measured momentary pressure does not exceed the specified maximum pressure value.

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In particular, the room pressure in the enclosed space atmosphere, set before the flood, is maintained even if the ignition level must be set within a very short time, and in particular within the first 60 seconds after the beginning of the flood in the atmosphere.

In particular, the use of a pressure relief device with a controlled pressure relief device in the device according to the invention makes it possible to compensate continuously for the excess pressure which builds up in the surrounding atmosphere of the enclosed space at the time of the introduction of the extinguishing agent. In particular, the provision of the extinguishing device can be used to ensure that in the enclosed space an excess pressure is generated in principle, the magnitude of which is proportional to the momentary excess pressure produced by the introduction of the extinguishing agent.

The pressure relief device shall preferably be so designed as to compensate at least partly for the excess pressure created by the sudden introduction of the gaseous extinguishing agent into the protective area.

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The invention provides that the pressure-generating device is controllable by means of a controller, preferably so that the pressure in the room atmosphere does not exceed a prescribed maximum pressure value.

The solution of the invention therefore makes it possible to use a fire-extinguishing system based on the principle of inertisation in a closed room with an atmosphere with a reduced pressure (underpressure) compared to the air pressure of the normal outdoor atmosphere, as may be the case, for example, in laboratory rooms.

It is essential that the pressure compensation or pressure relief obtained by the solution of the invention is decoupled from the spatial design of the enclosed space, and in particular from the size or volume of the room, since, regardless of the volume of the room, the pressure relief device can compensate for a pressure change in the room that occurs when a gaseous extinguishing agent is introduced.

The method of the invention is a technical implementation of the fire prevention or fire suppression that can be achieved with the device described above.

In particular, the method of the invention is a particularly easy to implement but effective method for preventing fire and/or extinguishing a fire in an enclosed space effectively and reliably, by means of a pressure relief in the form of a pressure compensation, which makes it possible to compensate adequately for a change in pressure during the introduction of extinguishing agents into the atmosphere, so as to prevent damage to the enclosure.

This is achieved in particular by actively draining exhaust air from the (gaseous) atmosphere into the protective zone at any time, including during the introduction of extinguishing agents, thus ensuring that the room pressure reduced compared to the normal outdoor atmosphere pressure can be maintained at all times, including during the supply of extinguishing agents, by ensuring that, in principle, the total volume of fresh air and/or extinguishing agents injected into the space per unit time is less than or equal to the volume of gases drained or removed from the (gaseous) atmosphere per unit time.

Advantageous developments of the process according to the invention are given in claims 2 to 10 and the device according to the invention in claims 11 to 13.

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As already indicated, the removal of exhaust air from the gaseous atmosphere can be achieved in a number of ways. First, it is useful that at least part of the exhaust air is actively sucked out of the space through an exhaust system. This involves not only the removal of exhaust air from the space atmosphere but also the removal of exhaust air from the space volume. If the exhaust air is used to discharge exhaust air in a regulated manner in order to compensate for the increase in the space pressure that occurs when inert gas is introduced, the exhaust air must be discharged in a relatively short time, so that it can be recovered in a relatively short time, or even with a large amount of exhaust gas, in the case of a fire extinguisher, which can be used in a realistic way.

For this reason, the solution of the invention provides for a pressure-generating device, which may be operated separately from the exhaust system, to provide the pressure compensation required for the inert gas supply.

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The solution of the invention uses a compressor as a pressure-generating device designed to compress, i.e. compress, the volume of at least part of the exhaust air to be removed from the gaseous atmosphere. The compressor is located inside the room so that the exhaust air compressed by the compressor can be stored in a high-pressure storage tank in the room.

Rather, the compressor is designed to reduce the volume of exhaust air to be removed from the gaseous atmosphere, thus compensating for the excess pressure created by the inert gas flow.

As already indicated, the compressor and the high-pressure storage tank are located inside the enclosed space This embodiment has the advantage of providing pressure compensation without requiring major structural measures.

In principle, the compressor should have a sufficiently high volume throughput to ensure that the intake volume of the compressor is greater than or equal to the volume flow of the total gas air supplied to the atmosphere as fresh air and/or extinguishing agent.

As an alternative or in addition to a compressor-like pressure-generating device, it is of course also conceivable that the exhaust air to be discharged into the atmosphere is removed from the interior by means of an exhaust pipe system.

In particular, in a laboratory room where the ambient atmosphere may contain substances, particles or substances (such as viruses) hazardous to health, it is preferable that the exhaust air compressed by means of the compressor and, if necessary, stored in the high pressure storage tank is not discharged to the external atmosphere until after appropriate treatment, in particular filtration and/or sterilisation, in order to prevent the release of substances, particles, substances, etc. hazardous to health.

In principle, however, other solutions are conceivable as a pressure-generating device. For example, it would be conceivable to use devices for reducing the volume of gases in the enclosed space, which are operated with a fan. In a possible implementation of the pressure-generating device, for example, it may be envisaged that it has a suction device and an intake pipe system connected to the suction device. It is preferable that a control can be used to control the pressure-generating gas or air volume accurately sucked from the enclosed space through the intake pipe system by means of the suction device at any time. In this context, it is particularly conceivable that the device is designed as a real-time or a vacuum-generating device, but it is also possible to use a control device whose direction of actuation is more efficient than the one of the control unit, which can be set up with the help of a control unit, which can be used to control the pressure-generating unit, especially if the pressure is already set at a level which is comparable to the actual pressure.

If the latter embodiment has a fan as the control device, which allows the control to adjust not only the speed but also the rotation, it is possible to use the control device as an exhaust. An exhaust is a device designed to allow, for example, active ventilation of the enclosed space. The provision of such an exhaust can be particularly advantageous when, for example, after a fire, the smoke still present in the room must be removed or fresh air must be introduced into the room (for whatever reason).

With respect to the pressure relief or pressure compensation achievable by the solution of the invention, it is preferable to measure the respective volume flows of the fresh air supplied as exhaust, the exhaust air discharged and the extinguishing agent supplied as exhaust in the event of fire or for fire prevention and then to adjust the respective volume flows in such a way that at any time the difference between the volume flow of the atmosphere as a whole as fresh air and/or as extinguishing agent and the volume flow of exhaust air discharged from the atmosphere remains at a constant pre-determined value. However, if the enclosed space and an aerosol-discharged air-discharged space are separated by a pre-determined volume, this value should be maintained (or maintained) at a constant value, and the volume flow of exhaust gas in the enclosed space may be adjusted (or maintained) at a pre-determined value, even if the pressure is not constantly increased.

Alternatively or in addition to the above-mentioned system, it is advantageous to determine continuously or at specified times and/or events the difference between the pressure (space pressure) in the room and the pressure of the outer atmosphere and to compare it with a specified value, and to regulate the volume flow of the total air flowing into the space as fresh air and/or extinguishing agent and the total flow of the exhaust air flowing out of the space as a function of the comparison. This is a particularly easy to implement but nevertheless effective way of preventing pressure compensation in the enclosed space, even if a large amount of fire-fighting gas is introduced into the space in a short period of time, especially at the beginning of a Zulu phase.

In the latter case, the comparison and subsequent control should preferably be carried out by means of a controller, which should be designed to control a space-connected gas supply system, a space-connected inert gas source and a space-connected exhaust system and, where appropriate, a pressure-generating device, the volume flow of the total airflow into the atmosphere as fresh air and/or as extinguishing agent is equal to the volume flow of the exhaust air removed from the atmosphere if the difference between the determined room pressure and the ambient air pressure is less than the specified value; and/or the volume flow of the total airflow into the atmosphere as fresh air and/or extinguishing agent is less than the volume flow of the exhaust air removed from the atmosphere if the difference between the determined room pressure and the ambient air pressure is less than the specified value.

It should be noted that the difference between the air pressure in the room and the air pressure in the outer atmosphere can be determined by measuring the pressure in the room (room pressure) and the air pressure in the outer atmosphere.

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In addition to or as an alternative to a pressure measuring device, it is of course also conceivable to calculate the pressure in the atmosphere of the room. In such a pressure calculation, the volume of the enclosed room on the one hand and the amount of extinguishing agent introduced into the enclosed room on the other hand should preferably be taken into account.

As indicated above, the method of the invention is to establish an inertisation level in the event of a fire in the room by introducing an oxygen-displacing gas (inert gas) into the atmosphere as soon as possible after a fire has been detected. In order to detect a fire as early as possible and to initiate the fire-fighting phase, it is advantageous to measure continuously or at reasonable times and/or events in the atmosphere whether at least one fire-size exists, whereby in the event of detection a fire-size of the atmosphere is introduced into the room as the extinguishing agent. At the same time, the fire-fighting process should be maintained by fresh air. This is possible, for example, by measuring the fire-fighting characteristics of a fire, but this cannot be fully achieved if the smoke-fighting effect is relatively strong and can be maintained in the room.

Accordingly, a preferred further training of the device according to the invention is to provide that it has a device for detecting at least one fire signal size in the ambient atmosphere of the enclosed space. In addition, the device according to the invention should have a controllable extinguishing agent supply device, which is preferably designed to control the extinguishing agent supply device in the event of a fire in such a way that the supplied extinguishing agent is supplied directly, and thus in the shortest possible time, to the ambient atmosphere of the enclosed space.

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The device for detecting at least one fire signal size may be designed, for example, as an aspiration system, in which a representative fraction of the room atmosphere is actively absorbed via a pipeline or duct system, preferably at a number of points. This fraction can then be fed to a measuring chamber with the detector for detecting a fire signal size.

The controlled extinguisher supply system should, in a preferred implementation, have an inlet supply system connected to an inert gas source, i.e. a device providing the gaseous extinguisher. On the other hand, the inlet supply system should be connected to the interior of the enclosed space by means of gas exhaust nozzles. The exhaust nozzles should preferably be distributed within the enclosed space. Control of the extinguisher supply can be achieved by means of an appropriate control of control valves or similar devices.

It is not necessary for the fire extinguisher to have an inlet piping system connecting the inner enclosure to an inert gas source outside the enclosure, but it is also possible for the inert gas source to have at least one high pressure pipe within the enclosure, in which at least one high pressure pipe within the enclosure can store at least part of the fire extinguisher provided under high pressure. It is preferable that at least one of the inert gas sources be directed to the controlled exit, indicating which direction the fire extinguisher is directed.

The use of a high pressure pipe may be, for example, in an intermediate ceiling of the enclosed room or under the ceiling of the room to store the extinguishing agent in it.

In particular, it is preferable to have several controllable exhaust valves on at least one high pressure pipe to allow the gas extinguisher to flood the enclosed space as quickly as possible if necessary.

However, as an alternative or in addition to the latter embodiment, where at least part of the extinguishing agent supplied is stored under high pressure in at least one high pressure tube, it is also conceivable that the inert gas source has at least one high pressure cylinder and preferably a battery of high pressure cylinders. These high pressure cylinders may be located outside the enclosed space. In this case, a supply pipe system belonging to the extinguishing agent supply system shall be provided, connecting the at least one high pressure cylinder or the battery of high pressure cylinders to the interior of the enclosed space.

Such high-pressure cylinders may be, for example, commercial high-pressure cylinders designed for a pressure range of 200 to 300 bar. Of course, other facilities for supplying the extinguishing agent or storing the extinguishing agent are also available. The essential thing is that in the event of a fire, the extinguishing agent provided can be introduced into the enclosed space quickly, i.e. in the shortest possible time, in order to effectively prevent a fire or fire from spreading in the room. In particular, it is possible to extinguish a fire as quickly as possible.

The solution of the present invention can also be used with chemical extinguishers.

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As already indicated, chemical extinguishers, such as HFC-227ea or NOVEC®1230, can be used as gaseous extinguishers. The extinguisher, known as HFC-227ea under the ISO designation HFC-227ea, removes heat from the fire, which is achieved by mostly physical action (cooling) and a small chemical intervention in the combustion process, thus achieving a fire suppression. This extinguisher has a fast extinguishing effect. There are also few restrictions on its use as long as the extinguishing area is relatively dense to achieve and maintain the necessary extinguishing concentration. However, high temperatures can be considered the most dangerous during the extinguishing process.

The chemical extinguisher NOVEC®1230 is a particularly environmentally friendly chemical extinguisher that breaks down in the atmosphere in about 5 days and has no adverse effects on the ozone layer and the greenhouse effect.

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In order to make the solution of the invention particularly effective for such a preventive measure, it is preferable that the device also be equipped with an oxygen measuring device to measure the oxygen content of the ambient atmosphere of the enclosed space. Depending on the oxygen content of the ambient air of the enclosed space, the controller will give a corresponding control signal to the fire extinguisher supply device. The control signal will indicate whether the ambient atmosphere of the enclosed space needs to be further supplied with inert gas or whether the inert gas supply can be stopped since the critical oxygen content of the ambient atmosphere has already been reached.

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When the solution of the invention is used as a fire prevention measure, it is preferable to control the volume flow of the inert gas or inert gas mixture introduced into the room atmosphere for fire prevention purposes in such a way as to initially set and maintain a basic inertisation level in the room atmosphere, and in the event of a fire to control the volume flow of the inert gas or inert gas mixture introduced into the room atmosphere in such a way as to set and maintain a full inertisation level.

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Finally, it is still preferable for the method of the invention to determine the quality of the ambient air continuously or at specified times and/or events, regulating the volume flow of fresh air supplied to the atmosphere as fuel air depending on the determined quality of the ambient air.

In particular, if the solution is used in a room, e.g. a laboratory room, where the room atmosphere may contain substances, particles, etc., hazardous to health, the exhaust air from the room atmosphere should be treated first, in particular filtered or, if necessary, sterilised before being released to the outer atmosphere, but preferably at least part of the exhaust air from the room atmosphere may be returned to the room atmosphere as fresh air after an air treatment.

The following figures give a detailed description of the preferred embodiments of the device according to the invention: Figure 1a first embodiment of the device according to the invention in a schematic representation;Figure 2a second embodiment of the device according to the invention in a schematic representation;Figure 3a flow diagram to illustrate the pressure compensation or pressure relief in an enclosed space which can be achieved with the solution according to the invention.

Figure 1 shows a first embodiment of the device of the invention for extinguishing a fire in a closed room 10. The device has an inert gas source 11 for supplying a gaseous extinguishing agent under normal conditions. In the embodiment shown, the inert gas source 11 includes a gas cylinder battery 11a located outside room 10 in which the extinguishing agent, such as nitrogen, is stored under high pressure.

The high-pressure flasks 11a are connected to compartment 10 by means of an extinguishing agent supply device 17; in particular, the extinguishing agent supply device 17 includes, on the one hand, an inlet pipe system 17a and, on the other hand, a gas outlet system 17b located inside compartment 10. The extinguishing agent supply device 17 is designed so that, in the event of a fire (or if necessary), the extinguishing agent stored in the high-pressure flasks 11a can be supplied to the enclosed compartment 10 as quickly as possible. In particular, the extinguishing gas can be released into the surrounding atmosphere of compartment 10 in the shortest time via the solutions 17b, so that, for example, in compartment 10 the necessary complete extinguishing can be achieved.

In order to ensure that the extinguishing agent contained in the high pressure cylinders 11a can be supplied to the room atmosphere in a regulated manner, the extinguishing agent supply device 17 shall also be equipped with a controllable V1 valve which is fully or partially opened in the event of fire (or if necessary) to connect the high pressure cylinders 11a to room 10 and allow the flooding of room 10 with the gaseous extinguishing agent.

The device of the invention shown in Figure 1 also has a pressure relief device 12 comprising a pressure relief device 13 and a control 14.

The pressure-reduction device 13 is connected to the enclosure 10 by suction openings 13c, which allows the suction device 13a to draw or draw air or gas from the interior of the room and to discharge it outwards, for example as exhaust air.

The controller 14 of the pressure-generating device 13 is connected to the controller 13a on the one hand and to a controllable control valve V2 of the pressure-generating device 13 on the other hand.

In particular, the control unit 14 is designed to control the pressure measuring device 13a of the pressure relief device 13 in such a way that the pressure px in the atmosphere does not exceed a prescribed maximum pressure value pmax, depending on the pressure px in the atmosphere of the enclosed room 10. To this end, the control unit 14 shown in Figure 1 has a pressure measuring device 15 to detect the physical pressure of the gases present in the atmosphere of the enclosed room 10. The pressure measuring device 13a is set to 15 times the maximum pressure px in the atmosphere, either continuously or to be applied or to be applied.

In the embodiment shown in Figure 1, the intake manifold 13a is designed as a fan. The control signal given by the control unit 14 to the intake manifold 13a when the specified maximum pressure pmax is exceeded preferably adjusts both the speed and the direction of rotation of the fan 13a. This allows the intake manifold 13b connected to the intake manifold 13a to discharge, in principle, a sufficient quantity of gas or air from the atmosphere of the enclosed room 10 per unit of time. This ensures that, even in the event of a sudden release of gas extinguishing agent, the px momentum of the pressure pmax prevailing in the room 10 does not exceed the maximum pressure pmax.

It is also conceivable, of course, that the px momentary pressure value is not measured but calculated or estimated on the basis of the amount of extinguishing agent introduced. In this case, the control 14 should be designed to control the extinguishing agent supply device 17 accordingly, so that the supplied extinguishing gas is fed into the room atmosphere in a regular manner.

In a further development of the solution of the invention, which has also been incorporated in the exemplary embodiment shown in Fig. 1, the fire extinguishing system is additionally equipped with a fire detection system 16 to detect at least one fire size in the room atmosphere of the enclosed room 10.

The signals transmitted by the fire detection device 16 to the controller 14 preferably continuously or at specified times or events are used by the controller 14 - if necessary after further processing or evaluation - to control the fire suppression device 17 and/or the control valve V1 accordingly.

As indicated above, in the embodiment shown in Figure 1, the control 14 is designed to work in conjunction with the fan 13a used as a reference device to regularly direct the volume of gas or air to be drawn out of the atmosphere via the intake tube system 13b. Since the control 14 also optionally allows the rotation of the fan 13a, the sub-pressure device 13 can also, if necessary, introduce a certain volume of air or gas into the atmosphere of the enclosed room 10. This can be particularly advantageous if the room 10 is to be pressurised to a certain minimum pressure in relation to the outer atmosphere.

To this end, control 14 should compare the measured, estimated or calculated pressure px in the enclosed space 10 with the maximum pressure pmax on the one hand and the minimum pressure pmin on the other hand. The depressurizer 13 should be controlled accordingly if the instantaneous pressure px is greater than the maximum pressure pmax or less than the minimum pressure pmin. The depressurizer 13 should be controlled so that the instantaneous pressure px in the atmosphere of room 10 does not exceed the maximum pressure pmax and does not fall below the minimum pressure pmin.

In order to ensure, in principle, that, even in the event of failure or failure of the pressure-generating device 13, the pressure px in the ambient atmosphere of the enclosed space 10 does not exceed or fall below the specified maximum pressure pmax and/or the specified minimum pressure pmin, it may be provided as a safety measure that the pressure-discharge device 12 also has at least one (mechanical) pressure-discharge valve 18. The functioning of such a pressure-discharge valve 18 is known from the state of the art. The pressure-discharge valve 18 should be designed to open automatically when the first pressure of a p1 is exceeded in order to allow a discharge of pressure in the space 10.

It is preferable that the optional pressure relief valve 18 is further designed to close independently when the prescribed initial pressure value p1 is exceeded; the prescribed initial pressure value p1, above which the pressure relief valve 18 opens independently, is preferably greater than or equal to the prescribed maximum pressure value pmax used by the control 14 as the control sword for the control of the pressure relief device 13.

In a preferred development of the latter embodiment, where the system also has at least one pressure relief valve 18 which preferably works mechanically for the purpose of pressure relief reliability, the pressure relief valve 18 is also designed to open independently even if a second pressure value p2 is exceeded and to close again if the second pressure value p2 is exceeded.

In Figure 2 a further preferred embodiment of the device according to the invention is shown in a schematic representation. The embodiment shown in Figure 2 corresponds essentially to the embodiment described above with reference to Figure 1; however, the apparatus described in Figure 2 does not use a reference device as the pressure-generating device 13. Rather, a compressor 19 is used as the pressure-generating device 13 and is provided inside the chamber 10 to compress, if necessary, the volume of at least part of the exhaust air to be drawn from the gaseous atmosphere.

The high pressure storage tank 20 is connected to the outlet pipes 13b, 21 by a three-way valve V2, V3 and can, if necessary, discharge the compressed exhaust air 19 and/or the compressed exhaust air 20 stored in the high pressure storage tank 20 from the interior of the room 10.

The device shown in Figure 2 also comprises an exhaust system consisting of an exhaust fan 22 through which fresh air can be supplied to the room atmosphere via the supply pipe system 17a and the exhaust nozzle system 17b. In addition, an exhaust system with an exhaust fan 23 is provided which is connected to the interior of the room 10 via the pipe system 13b and the intake opening 13c and can regularly discharge exhaust air outwards.

In this way, it is possible to provide for an appropriate air exchange in the enclosed space 10 to exchange room air with outdoor air or fresh air. For example, in living rooms, an air exchange is necessary for the supply of oxygen, for the removal of carbon dioxide and for the transport of condensation water. But even in storage rooms that are not or only briefly occupied by people, an air exchange is often necessary to remove harmful components, such as the vapours of goods stored in the storage room. If the building or room vacuum is almost airtight, as the modern design provides, an irregular air exchange, which requires an uncontrolled and uncontrolled exchange of substances between the atmosphere and the outside, can no longer be provided with the help of an air exchange system.

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In the embodiment shown in Figure 2 an inert gas source is a gas cylinder battery 11a connected to the supply pipe system 17a by the three-way valve V1. The exhaust pipe system 13b is also connected to the supply pipe system 17a by a branch line 13d and a three-way valve V4. The valves V2 and V4 are controlled by the control 14 respectively, so that the branch line 13d, the valves V2, V4, the exhaust fan 23 and the circulator system 13b form a pipe system.

Although not explicitly shown in the figure 2 above, the supply pipe system 17a may be equipped with a volume flow sensor to capture the total volume flow to the atmosphere and to communicate the recorded value to the control 14.

Furthermore, although not explicitly shown in Fig. 2, a corresponding volume flow sensor may be provided in the pipe system 13b or 21 to measure the volume of exhaust air discharged from the room by the exhaust system per unit time and to report the recorded value to the controller 14; this is done by the controller 14 comparing the recorded volume flow with the recorded volume flow and controlling the volume flow and/or exhaust accordingly so that at any time the volume flow is less than or equal to the volume flow of exhaust air. In this way, a pressure raiser can be set and maintained in the room 10 relative to the normal atmospheric pressure.

As in the embodiment described in Figure 1, the control 14 is designed to adjust the valve V1 accordingly if necessary to form a fluid connection between the inert gas source 11a and the supply pipe system 17a, so that the inert gas (gas extinguishing agent) provided by the inert gas source 11a can be supplied to the room atmosphere in a regulated manner. Since it is necessary to rapidly reduce the oxygen content of the room atmosphere to at least the level of prevention of re-ignition in the event of a fire, in the case of detection of a pressure difference, the supply of the source of fresh air is introduced and only Zulu 11a extinguishing agent is introduced into the room atmosphere - which would not be possible in the case of a fire - in the case of a fire, which would not be significantly increased in the case of a reduction in the volume of the room atmosphere - compared to the usual Zulu 11a extinguishing agent - which would be provided by a reduction in the volume of the room atmosphere - which would not be possible in the case of a significant increase in the volume of the room atmosphere.

To prevent this, the pressure-generating device 13 is used in the embodiment shown in Figure 2 which compresses the volume of at least part of the exhaust air to be drawn from the room atmosphere and stores it in the high-pressure storage tank 20 already mentioned.

The provision of the pressure-reduction device 13 thus allows the exhaust volume flow to be at least equal to the exhaust volume flow even when inert gas is injected into room 10 at a single time and the exhaust system itself is not designed to divert a sufficiently large exhaust volume flow from the room atmosphere.

The functioning of the pressure relief or pressure compensation achieved in the solution of the invention is again schematically shown in the flow diagram shown in Figure 3.

The pressure relief or pressure compensation inside chamber 10 is initiated when gaseous extinguishing agent is introduced into the protection area from the inert gas source 11a (step S1). The pressure measuring device 15 then measures the pressure px inside chamber 10 and the measured pressure is fed to the controller 14 (step S2). The controller 14 then determines whether the measured pressure px reaches a maximum limit value pmax which is predictable and preferably stored in a controller free storage (step S3). If this is not the case (NE), the flow diagram returns to the second procedure (step S2), where the measured pressure px inside chamber 10 is measured.

However, if the measured pressure px is determined at step S3 to reach the preset limit pmax (JA), the control 14 shall give an appropriate control signal to the pressure relief device 13 (step S4). The pressure relief device 13 shall conduct exhaust air from the ambient atmosphere of the enclosed space 10 until the pressure relief px returns to a value below the preset limit pmax (steps S5 to S7).

As described above, the pressure-generating device 13 may be either a drainage system with a suction system 13a to discharge exhaust air from the (gas) atmosphere and the volume of the room in a controlled manner or a compressor 19 to compress the volume of exhaust air to be discharged from the atmosphere for pressure compensation and thus provide pressure relief.

Although not shown in Figures 1 and 2, it may be necessary to provide a filter in the exhaust pipe system 13b to purify or treat the exhaust air from the room atmosphere and the volume accordingly before it is either returned to the room atmosphere as exhaust air or discharged to the outer atmosphere.

The solution is not limited to fire extinguishers which provide a fire suppression measure only in the event of a fire by the sudden introduction of an extinguishing gas into the enclosed space 10.

In such a case, it is preferable to use an inert gas or a mixture of inert gases as the extinguishing agent, the suppression or extinguishing of which is based on the so-called suffocation effect.

In addition, it is advantageous if the device also has an oxygen measuring device 19 to detect the oxygen content in the ambient atmosphere of the enclosed room 10. This oxygen measuring device 19 is preferably designed as an aspiration system, as is the device 16 to detect at least one fire signal.

Err1:Expecting ',' delimiter: line 1 column 271 (char 270)

Err1:Expecting ',' delimiter: line 1 column 80 (char 79)

In this further development of the solution of the invention, the inert gas, nitrogen in a favourable way, is extracted on site from the ambient air. The inert gas generator or nitrogen generator 11b' works, for example, according to the membrane or PSA technique known from the state of the art to produce an air enriched with nitrogen with, for example, 90% vol. to 95% vol. nitrogen content. This nitrogen enriched air serves as an inert gas, which is supplied to room 10 via the supply pipe system 17a. The oxygen enriched air generated in the production of the inert gas is discharged to the outside through another pipe system.

Err1:Expecting ',' delimiter: line 1 column 203 (char 202)

The solution to the present invention is not limited to the exemplary embodiments shown in the figures, but rather variations of the described characteristics, as described in the attached claims, are conceivable.

In particular, it is conceivable to use as an inert gas source 11 not a gas cylinder battery outside the enclosed space 10 but a high pressure pipe in the enclosed space 10 in which at least part of the supplied extinguishing agent should be stored under high pressure and which should have at least one controlled exhaust valve 14 and a valve for the extinguishing agent supply 17.

Claims (13)

1. An inerting method for preventing fire and for extinguishing fire in an enclosed room (10), particularly a laboratory, wherein fresh air is fed into the atmosphere of the room in regulated manner as supply air and exhaust air is discharged from the atmosphere of the room in regulated manner, and wherein in the event of a fire or to prevent a fire, an extinguishing agent which is gaseous under normal conditions is fed into the atmosphere of the room as the supply air, wherein a reduced room pressure (p_x) compared to the normal atmospheric pressure is set and/or maintained in the room (10) by the total volumetric flow of the supply air fed to the atmosphere of the room as fresh air and/or as extinguishing agent being at all times less than or equal to the volumetric flow of exhaust air discharged from the room's atmosphere, wherein the difference between the pressure prevailing in the room and the air pressure of the ambient air is determined continuously or at predefinable times and/or upon predefinable events and compared to a predefinable value, and wherein the total volumetric flow of supply air fed to the atmosphere of the room as fresh air and/or extinguishing agent as well as the volumetric flow of exhaust air discharged from the room's atmosphere is regulated as a function of said comparison, wherein the total volumetric flow of supply air fed to the atmosphere of the room as fresh air and/or extinguishing agent is equal to the volumetric flow of exhaust air discharged from the room's atmosphere when the difference determined between the room pressure (p_x) and the air pressure of the ambient air corresponds to the predefined value, characterized in that the respective volumetric flows of the fresh air fed in as supply air, the discharged exhaust air and the extinguishing agent fed in as supply air in the event of a fire or to prevent a fire are measured, and that the respective volumetric flows are regulated such that the difference between the total volumetric flow of the supply air fed into the room's atmosphere as fresh air and/or as extinguishing agent as well as the volumetric flow of the exhaust air discharged from the room's atmosphere assumes a constant predefinable value at all times, wherein the room (10) has a gas-tight and aerosol-tight structural shell, and wherein the constant predefinable value is preferably zero; and that in the case of extinguishing agent being supplied as the supply air, at least a portion of the exhaust air to be discharged from the room's atmosphere is compressed by means of a compressor (19) arranged inside the enclosed room (10), wherein the intake volume of the compressor (19) is greater than or equal to the total volumetric flow of the fresh air and/or extinguishing agent fed into the room's atmosphere as supply air, and wherein the exhaust air discharged from the atmosphere of the room and compressed by the compressor (19) is preferably temporarily stored in compressed form in a high-pressure storage tank (2) arranged inside the enclosed room (10).
2. The method according to claim 1, wherein at least a portion of the exhaust air compressed by the compressor (19) is discharged to the outside following treatment, particularly filtering or sterilizing.
3. The method according to one of the preceding claims, wherein the total volumetric flow of the supply air fed to the atmosphere of the room as fresh air and/or extinguishing agent is less than the volumetric flow of exhaust air discharged from the room's atmosphere when the difference determined between the room pressure (p_x) and the air pressure of the ambient air is less than the predefined value.
4. The method according to any one of the preceding claims, wherein the difference between the room pressure (p_x) and the air pressure of the ambient air is determined by measuring the pressure (p_x) in the room and the air pressure of the ambient air.
5. The method according to any one of the preceding claims, wherein at least one fire characteristic is measured in the atmosphere of the room continuously or at predefinable times and/or upon predefinable events, and whereby upon a fire characteristic being detected, the extinguishing agent is fed into the room atmosphere as supply air; and whereby upon a fire characteristic being detected, the fresh air normally supplied as the supply air is preferably discontinued or whereby the volumetric flow of the extinguishing agent fed into the room atmosphere in the event of a fire characteristic being detected is greater than the volumetric flow of the fresh air normally supplied to the room atmosphere.
6. The method according to any one of the preceding claims, wherein to prevent fire, both fresh air as well as extinguishing agent is fed into the room's atmosphere as supply air.
7. The method according to claim 6, wherein the concentration of extinguishing agent in the room's atmosphere is determined continuously or at predefinable times and/or upon predefinable events, and whereby the volumetric flow of the extinguishing agent fed into the room's atmosphere for the purpose of preventing fire is regulated as a function of the extinguishing agent concentration as determined such that a predefinable extinguishing agent concentration can be set and/or maintained in the room's atmosphere; and whereby the extinguishing agent is preferably an inert gas or an inert gas mixture, and whereby the extinguishing agent concentration in the room's atmosphere is preferably determined indirectly by measuring the oxygen content.
8. The method according to claim 7, wherein the volumetric flow of an inert gas or inert gas mixture supplied to the room's atmosphere for the purpose of preventing fire is regulated such that a base inertization level, which is higher than the characteristic reignition prevention level for the room (10), is set and maintained in the room's atmosphere, and whereby in the event of a fire, the volumetric flow of the inert gas or Inert gas mixture supplied to the room's atmosphere is regulated such that a full inertization level, which is equal to or lower than the characteristic reignition prevention level for the room (10), is set and maintained.
9. The method according to any one of the preceding claims, wherein the quality of the room's air is determined continuously or at predefinable times and/or upon predefinable events, and whereby the volumetric flow of the fresh air supplied to the room's atmosphere as supply air is regulated as a function of the quality of the air determined in the room; and whereby the quality of the room's air is preferably indirectly determined by measuring the CO_Z2content in the room's atmosphere.
10. The method according to any one of the preceding claims, wherein at least a portion of the exhaust air discharged from the room's atmosphere is refed back into the room's atmosphere as fresh air after being treated.
11. A device for realizing the method according to any one of claims 1 to 10, wherein the device comprises at least one mechanism (11) for providing an extinguishing agent which is gaseous under normal conditions and for immediately introducing the gaseous extinguishing agent into the room atmosphere of the enclosed room (10) when it has been determined that a fire has broken out in said enclosed room (10), wherein the device comprises a pressure relief mechanism (12) having a negative-pressure generating means (13) and a controller (14), wherein the controller (14) is designed to control the negative-pressure generating means (13) as a function of the pressure (p_x) prevailing in the atmosphere of the enclosed room (10) such that the pressure (p_x) prevailing in the room's atmosphere does not exceed a predefinable maximum pressure value (p_max), and wherein the device further comprises a pressure measuring mechanism (15) for measuring the physical pressure of the gas within the room's atmosphere, wherein the pressure measuring mechanism (15) is designed to measure the momentarily current room pressure (p_x) continuously or at predefined times and/or upon predefined events and feed said measured values to the controller (14), wherein the controller (14) is designed to accordingly control the negative-pressure generating means (13) based on the current pressure value (p_x), characterized in that the negative-pressure generating means (13) comprises a compressor (19) for compressing at least a portion of the exhaust air to be discharged from the room atmosphere and a high-pressure storage tank (20) for temporarily storing the exhaust air compressed by the compressor (19), and that a fire detection mechanism (16) is provided to detect at least one fire characteristic in the room's atmosphere continuously or at predefinable times and/or upon predefinable events and send the corresponding signals to the controller (14), wherein the controller (14) is designed to control an extinguishing agent feeding mechanism (17) such that in the event of a fire characteristic being detected, the extinguishing agent is fed into the room's atmosphere as supply air, wherein the compressor (19) and the high-pressure storage tank (20) are arranged inside the enclosed room (10).
12. The device according to claim 11, wherein the controller (14) is further designed to control the negative-pressure generating means (13) as a function of the pressure (p_x) prevailing in the atmosphere of the enclosed room (10) such that the room pressure (p_x) prevailing in the room's atmosphere does not fall below a predefinable minimum pressure value (p_min).
13. The device according to claim 11 or 12, wherein the controller (14) controls the compressor (19) such that the intake volume of the compressor (19) is greater than or equal to the total volumetric flow of the fresh air and/or extinguishing agent fed into the room's atmosphere as supply air.