Method for extinguishing a flame front and extinguishing device

Abstract

Method for extinguishing a flame front in a gas pipeline (2) wherein the method comprises the steps: (a) Introducing an extinguishing agent under overpressure into an extinguishing area (L) of the gas pipeline (2), and furthermore (b) Introducing a barrier liquid into a barrier area (S) of the gas pipeline (2) such that the barrier liquid remains in the barrier area (S) in such a way that any gas flowing through the gas pipeline (2) must flow through the barrier liquid in the barrier area (S), characterized in that the barrier liquid is introduced into the gas pipeline (2) after the extinguishing agent.

Description

[0001] The invention relates to a method for extinguishing a flame front in a gas pipeline and, according to a second aspect, to an extinguishing device for a gas pipeline.

[0002] Gas pipelines are transport systems for gases, especially flammable gases. These include, for example, pipelines that transport gases, such as natural gas, over long distances. They can also be shorter gas pipelines, such as those between a refinery and a gas storage tank, or from a transport vehicle to a gas storage tank.

[0003] In gas pipelines carrying flammable gases, there is always a risk of ignition, for example, due to a spark. Such a spark can be caused by faulty electrical equipment, such as sensors, or by electrostatic discharges. If the gas ignites in the pipeline, a flame front forms and spreads through the pipe. This can cause severe damage to the pipeline and its surroundings.

[0004] DE 41 26 932 A1 describes a device with a dip arrestor in which the effectiveness of the arrestor against flame propagation is improved by adding a non-flammable liquid to the flowing gas and, in addition, by guiding the flame returning in the pipe over a pool of water upstream of the dip arrestor. WO 2017 070 737 A1, on the other hand, describes a device that prevents a flame from flashing back in the vent pipe of a coal mine.

[0005] CN 2 06 924 279 U describes a device in which a liquid-filled section of a gas line is used to prevent the propagation of flame fronts or sparks. The gas flowing through the line exits below the liquid level and must therefore pass through the liquid. This prevents the propagation of flames.

[0006] A particular danger arises from the possibility that such a flame front could reach a storage tank or a gas transport vehicle connected to the gas pipeline, such as a gas tanker, and cause the stored gas to explode. Such an accident could lead to enormous material and environmental damage.

[0007] Advantageously, gas pipelines are therefore equipped with devices to prevent such an accident. These can include, for example, extinguishing systems or flame arresters.

[0008] Flame arresters are permanently installed components in gas pipelines. They feature numerous openings through which the gas can pass, but the flame is prevented from reaching the pipe. Due to their design, they necessarily increase the flow resistance in the gas pipeline. This necessitates larger dimensions for the gas pipelines and the gas pumps. Flame arresters are particularly disadvantageous when using gases containing impurities, as these impurities can clog the arresters, reducing the flow rate. In such systems, the flame arresters require regular, costly cleaning or replacement.

[0009] Fire extinguishing devices are known, for example, in the form of extinguishing nozzles, through which extinguishing agent is sprayed into the gas line under high pressure when a spark or flame is detected. For this purpose, pressure cartridges are used, for example, that spray a predetermined quantity of extinguishing agent.

[0010] Once a flame front has formed in a gas pipeline, there is always a risk of it reigniting. Faulty electrical components, in particular, pose a high risk of reigniting the gas. This is especially problematic with extinguishing systems that use pressurized cartridges, as at least one cartridge is consumed for each extinguishing operation. Therefore, the number of extinguishing operations that can be carried out is limited to the number of cartridges available. One way to counteract this is to shut off the gas pipeline, for example, by stopping the gas supply. However, this means that no more gas flows through the pipeline, rendering it at least temporarily unusable.

[0011] The object of the present invention is to propose a method for extinguishing a flame front of a gas pipeline and an extinguishing device for carrying out this method, with which the aforementioned disadvantages can be reduced.

[0012] The invention solves the problem by a method for extinguishing a flame front in a gas pipeline, wherein the method comprises the steps: a) Introducing an extinguishing agent under overpressure into a fire extinguishing area of ​​the gas pipeline, and furthermore b) Introducing a sealing liquid into a sealed area of ​​the gas pipeline, such that the sealing liquid remains in the sealed area in such a way that any gas flowing through the gas pipeline must flow through the sealing liquid in the sealed area, the sealing fluid is introduced into the gas line after the extinguishing agent.

[0013] The extinguishing agent is intended to extinguish the flame front. For this purpose, the extinguishing agent is introduced into a designated extinguishing zone within the gas pipeline under positive pressure. In the simplest case, this extinguishing zone is an area within the gas pipeline where the extinguishing agent has an extinguishing effect.

[0014] Overpressure is understood to mean, in particular, a pressure that is above normal atmospheric pressure. Preferably, the extinguishing agent is introduced at an overpressure relative to the pressure prevailing in the gas line during normal operation, which is also referred to as the operating pressure. Preferably, the overpressure relative to the operating pressure is at least 2 bar, more preferably at least 5 bar. Relative to normal atmospheric pressure, the overpressure is preferably at least 10 bar, more preferably at least 20 bar.

[0015] The overpressure makes it possible to use a smaller quantity of extinguishing agent than would be possible without it, since the overpressure allows for better and finer atomization of the extinguishing agent, for example, water, thereby increasing the total surface area of ​​the extinguishing agent relative to its volume. Furthermore, a larger quantity of extinguishing agent can be introduced into the gas line per unit of time. This is advantageous for extinguishing the rapidly moving flame front in a targeted and precise manner with a sufficiently large quantity of extinguishing agent. Preferably, the overpressure is selected such that at least half of the extinguishing agent, and in particular all of it, is introduced into the gas line within 30 milliseconds.

[0016] Furthermore, a barrier fluid is introduced into a barrier zone of the gas pipeline. In the simplest case, the barrier zone is the area within the gas pipeline where the barrier fluid exerts a blocking effect. This means that it remains in the barrier zone in such a way that any gas flowing through the gas pipeline must flow through the barrier fluid. The fluid thus forms a barrier against further flame fronts. A non-flammable liquid, particularly water, is preferably used as the barrier fluid. It is possible, and in some embodiments of the invention advantageous, if at least a portion, and in particular all, of the barrier fluid is introduced into the gas pipeline under overpressure. This allows the barrier fluid to establish a blocking effect more quickly. However, the device that may be necessary to apply the pressure often presents a higher risk of failure.It is particularly preferred that the sealing fluid is introduced into the gas pipeline solely under the influence of gravity.

[0017] According to the invention, the sealing fluid remains in the sealed area of ​​the gas pipeline in such a way that gas flowing through the pipeline must flow through the sealing fluid within the sealed area. It is also particularly in accordance with the invention if a mixture or layer of sealing fluid and extinguishing agent is present, through which the gas must flow. This means that at least at one point the flowable cross-section of the gas pipeline is completely filled with sealing fluid or with a mixture or layer of sealing fluid and extinguishing agent. Consequently, the gas flowing through the gas pipeline cannot bypass the fluid but must pass through the barrier thus formed.

[0018] Such a barrier offers the advantage that a second or subsequent flame front reaching the barrier area cannot penetrate the barrier fluid and / or be extinguished by it. Furthermore, it remains possible for gas to flow through the gas line and the barrier fluid. Despite the increased flow resistance caused by the barrier fluid, the functionality of the gas line is therefore generally maintained. The flow velocity and quantity limits specified for the respective design of the extinguishing device must be observed.

[0019] The method according to the invention therefore makes it possible to operate a gas pipeline without the need for flame or penetration protection devices that increase flow resistance. In the event of a first flame front occurring, it is extinguished with the extinguishing agent. The barrier fluid introduced into the restricted area then effectively prevents any further flame fronts from passing through.

[0020] Preferably, the barrier fluid introduced into the barrier area prevents the movement of a flame front from one side of the barrier area to the other side of the barrier area.

[0021] According to the invention, the sealing fluid is introduced into the line after the extinguishing agent.

[0022] Consequently, the extinguishing agent is first introduced into the gas pipeline to extinguish the flame front, and then the sealing liquid is introduced into the containment area. The sequential nature of these actions is understood to include situations where the introduction of the extinguishing agent and the sealing liquid partially overlap, provided that the majority of the sealing liquid is introduced into the gas pipeline after the extinguishing agent.

[0023] In this way, it is particularly possible to first extinguish the flame front with the appropriately sized extinguishing agent and the necessary temporal precision, and then to introduce the barrier fluid, which requires far less temporal precision. Furthermore, various media, especially liquids, can be used as extinguishing agents and barrier fluids to meet the different requirements.

[0024] Preferably, the extinguishing agent is also the sealing fluid.

[0025] Preferably, the deletion area and the exclusion area coincide spatially, at least partially; in particular, one of the areas is completely part of the other area.

[0026] Preferably, the extinguishing agent and the sealing fluid are introduced in the same area within the gas pipeline. This makes it possible, for example, to design the device required for introducing the extinguishing agent and the sealing fluid as a single assembly, since these do not need to be arranged at different locations.

[0027] Preferably, the containment zone and / or the extinguishing zone are located in a specially designed compartment within the gas pipeline. This compartment is, for example, part of a separate extinguishing device that is inserted into or integrated into the gas pipeline. Since the containment fluid increases flow resistance after the initial flame front has been extinguished, the gas pipeline should be returned to its original state. This is particularly easy if the separate extinguishing device can be replaced. Alternatively or additionally, the compartment within the gas pipeline serving as the containment zone and / or extinguishing zone has a drain through which the containment fluid can be drained from the containment zone. For this purpose, the gas pipeline should be closed and the gas flow stopped.

[0028] Advantageously, to introduce the extinguishing agent into the extinguishing area, a closure is opened, in particular a valve is switched and / or a membrane is destroyed.

[0029] Preferably, the overpressure ruptures a membrane that fluidically separates the extinguishing agent from the extinguishing area, allowing the extinguishing agent to be introduced into the extinguishing area. Preferably, a pressure surge is applied to the extinguishing agent for this purpose. This surge can be applied in addition to any existing overpressure under which the extinguishing agent may be located.

[0030] For a method of extinguishing a flame front in a gas pipeline, high reliability and low susceptibility to failure are extremely advantageous, as a failure of the method could lead to a serious catastrophe. High reliability is achieved by introducing the extinguishing agent into the extinguishing area through a ruptured membrane by applying overpressure. In particular, a valve is not necessarily required to introduce the extinguishing agent. Instead, preferably only a pressure surge is applied to the extinguishing agent, which is sufficiently strong to rupture the membrane.

[0031] The membrane can be made of a plastic, particularly PTFE. However, it is also possible, and in some embodiments advantageous, for the membrane to be made of a metal or alloy. This allows, for example, higher pressures in an extinguishing agent container without damaging the membrane. Preferably, the membrane is only damaged by an additional pressure surge. Normal pressure typically prevails in the extinguishing agent before the device is triggered. The extinguishing agent is preferably subjected to a single pressure surge that damages the membrane. Preferably, the membrane has at least one, and preferably several, material weaknesses. These are formed, for example, by microperforations in the membrane that do not impair its sealing against the extinguishing agent, by notches introduced into the membrane, or by areas of reduced material thickness.Combinations of different material weakenings are also possible, of course. By selecting the type of material weakening and its position within the membrane, it is preferably predetermined, and particularly reproducible across multiple membranes, how and where the membrane is damaged by the pressure surge. This leads, in particular, to increased reliability and operational safety.

[0032] According to another aspect, the invention solves the problem by means of an extinguishing device which has at least one container for receiving extinguishing agent and sealing fluid and is set up to carry out a method described herein.

[0033] It is possible, and in certain embodiments advantageous, for the extinguishing device to be attached to an existing gas pipeline. For this purpose, for example, the extinguishing device is arranged on a gas pipeline, and the gas pipeline is provided with at least one opening through which the extinguishing agent and the sealing fluid can be introduced into the gas pipeline. This embodiment is particularly advantageous for the simple retrofitting of existing gas pipelines with the extinguishing device according to the invention.

[0034] However, it is also possible, and in certain embodiments advantageous, for the extinguishing device to have at least one chamber that is integrated into the gas line and thus becomes part of it. If the flame front is extinguished in a chamber of the extinguishing device that, in its installed state, has become part of the gas line, this is considered to be extinguishing the flame front within the gas line. In this embodiment, the extinguishing device is therefore not arranged on the outside of the gas line, but integrated into it, so that the gas flows through the chamber of the extinguishing device.

[0035] The extinguishing device has at least one chamber with at least two openings through which the gas flows from a supply section of the gas pipeline, through the extinguishing device, and into a discharge section of the gas pipeline. For integration, the extinguishing device preferably has a supply flange and a discharge flange, via which it is connected to the supply and discharge sections of the gas pipeline. Thus, during operation of the gas pipeline, the gas flows from the supply section through the extinguishing device's chamber into the discharge section. In its installed state, the extinguishing device is therefore part of the gas pipeline.

[0036] A particular advantage of this embodiment is that at least one compartment is specifically designed and dimensioned for the functions of the extinguishing device, namely extinguishing and sealing. Consequently, less consideration needs to be given to the local conditions of a gas pipeline. The extinguishing device is, in particular, replaceable as a whole, for example, after an extinguishing operation has been carried out. However, it is also possible for the extinguishing device to have a drain for the sealing fluid, allowing the sealing fluid to be drained from the sealing area. In this way, it is possible, for example, to continue operating an extinguishing device even after an extinguishing operation without replacing it completely. If a membrane used to introduce the extinguishing agent has been damaged, it can, for example, be replaced.Preferably, however, the entire extinguishing agent container containing the membrane is replaced, so that work within the extinguishing device itself is not necessary.

[0037] Preferably, the extinguishing zone and / or the containment zone is located in at least one chamber of the extinguishing device. Particularly preferably, both zones are located in the same chamber of the extinguishing device. Preferably, the opening of the chamber through which the gas flows in and / or the opening of the chamber through which the gas flows out is located below a liquid level of the containment liquid that forms after it has been introduced into the containment zone. Preferably, only one of the two openings is located below the liquid level. This ensures that any gas flowing through the gas line must flow through the containment liquid in the containment zone. The phrase "the containment liquid forms a liquid level" also includes, in particular, the presence of any remaining extinguishing agent together with, and especially mixed with, the containment liquid.

[0038] Preferably, the extinguishing device comprises at least one container for holding extinguishing agent and at least one container for holding sealing fluid. The spatial separation of the two media makes it particularly possible to select different media as the extinguishing agent and sealing fluid. Furthermore, it is particularly easy to provide different volumes.

[0039] Preferably, the extinguishing agent and the sealing liquid are identical liquids, in particular water, wherein at least one additive is preferably mixed into the extinguishing agent and / or the sealing liquid. This additive can be identical in both liquids or can also be different. Such additives are, for example, substances that affect viscosity or density. In some embodiments, however, it is also advantageous if the sealing liquid and the extinguishing agent are different liquids or mixtures of different liquids. This allows, for example, for the liquids to be tailored to their different intended uses.

[0040] Preferably, the container for holding the extinguishing agent, also referred to as the extinguishing agent container, is pressurized when the extinguishing agent is filled and the extinguishing device is ready for operation. For this purpose, the extinguishing agent container is, for example, not completely filled with extinguishing agent, with the pressure being exerted by a quantity of gas contained within the container. This pressure causes at least a partial, and in particular a complete, overpressure when the extinguishing agent is introduced into the extinguishing area.

[0041] The extinguishing device preferably includes a pressure generation device by means of which the extinguishing agent can be subjected to a pressure pulse. This is, for example, a gas container with a compressed gas, which can be directed into the extinguishing agent container via a valve, in particular a quick-acting valve. The pressure generation device is advantageously a gas generator, such as those known from airbags or similar applications. A pyrotechnic propellant charge containing sodium azide or guanidine nitrate is used, for example.

[0042] Preferably, the extinguishing agent container is separated from the gas line or the extinguishing device compartment, which is part of the gas line, only by a membrane. This membrane is preferably designed as described above.

[0043] Preferably, at least one container is designed to hold the extinguishing agent and the barrier fluid, wherein the container preferably has at least one extinguishing agent compartment and at least one barrier fluid compartment. Preferably, the at least one extinguishing agent compartment and the at least one barrier fluid compartment are fluidically connected or at least capable of being connected. The extinguishing agent compartment and the barrier fluid compartment can also exist without structural separation.

[0044] The extinguishing agent is preferably introduced into the extinguishing area of ​​the gas pipeline through an opening, which may be closed by the membrane. Due to the flow connection between the extinguishing agent compartment and the sealing fluid compartment, the sealing fluid can also be introduced into the gas pipeline through the same opening. If necessary, the flow connection must be established for this purpose.

[0045] The extinguishing agent compartment and the barrier fluid compartment are preferably separated by a partition wall. This partition wall preferably contains one or more valves that are opened when the barrier fluid is to be introduced into the Spree River area. Alternatively or additionally, the partition wall is perforated and has at least one opening that establishes a flow connection between the extinguishing agent compartment and the barrier fluid compartment.

[0046] Alternatively, the extinguishing agent compartment and the sealing liquid compartment can also be arranged in two separate components, which then together form the container.

[0047] The spatial and structural separation between the extinguishing agent room and the containment liquid room allows only one of the rooms to be replaced, removed, serviced or cleaned.

[0048] Particularly preferably, the extinguishing agent chamber is at least partially, but preferably completely, surrounded by the barrier fluid chamber. Preferably, several barrier fluid chambers are arranged radially around the central extinguishing agent chamber. The individual barrier fluid chambers are preferably fluidically connected. In this way, it is possible, for example, to introduce the extinguishing agent into the extinguishing zone by means of a pressure surge applied to the extinguishing agent in the extinguishing agent chamber, whereby the barrier fluid then flows from the barrier fluid chamber into the barrier zone. This design makes it easy to ensure that the pressure surge is exerted only on the extinguishing agent chamber and that it is pressurized to the necessary pressure. Furthermore, this design makes it particularly easy to introduce the barrier fluid after the extinguishing agent.

[0049] Preferably, the extinguishing agent and the barrier fluid can be triggered separately from each other, i.e., introduced into the extinguishing area or the barrier area.

[0050] Preferably, the extinguishing device has at least one detector for placement in or on the gas line, wherein the detector is configured to detect a flame front and wherein the extinguishing device has an electronic control, in particular an electronic data processing device, which is configured to carry out a method described herein depending on detector data of the at least one detector.

[0051] To detect a flame front, it is advantageous to have at least one detector arranged in the gas line. Such a detector could be, for example, a spark detector or an infrared flame detector. The at least one detector is preferably arranged upstream of the extinguishing device, relative to the direction of gas flow in the gas line. The extinguishing device preferably has at least two, and more preferably at least five, detectors, which can be arranged at varying distances from the extinguishing device in the gas line.

[0052] Depending on a detector signal, which, for example, encodes a detected spark or flame front, the extinguishing device is controlled by the electronic control system, and in particular, an extinguishing process is initiated. Preferably, the extinguishing process is triggered depending on the distance of the respective detector that detected a spark or flame front from the extinguishing device. Particularly preferably, the propagation speed of the flame front is determined based on the time interval between detector signals from different detectors, taking into account the spatial distance between the respective detectors, and the extinguishing process is triggered depending on the propagation speed thus determined.

[0053] The invention will be explained in more detail below with reference to the accompanying drawings. These drawings show Fig. 1 - a sectional view through an embodiment of the extinguishing device according to the invention, Fig. 2 - a perspective view of the extinguishing device from Fig. 1, and Fig. 3 - the extinguishing device from the Fig. 1 and Fig. 2, in the state integrated into a gas pipeline.

[0054] Fig. Figure 1 shows an embodiment of the extinguishing device 10 according to the invention, which can be integrated into a gas line 2 via a supply flange 22 and a discharge flange 20. During operation, gas flows through the supply flange 22 into an inner chamber 4 of the extinguishing device 10 and from there into an outer chamber 6. The inner chamber 4 is open at the bottom, allowing the gas to flow into the outer chamber 6. The gas then exits the extinguishing device 10 via the discharge flange 20. A flame front generally moves in the opposite direction, thus entering the extinguishing device 10 through the discharge flange 20 and exiting it through the supply flange 22, unless its progression is prevented by the extinguishing device 10. A container 12 is arranged above the inner chamber 4 and the outer chamber 6. This container 12 has a central cylindrical extinguishing agent chamber 16.This is completely surrounded laterally by a hollow cylindrical containment chamber 18. The extinguishing agent chamber 16 and the containment chamber 18 are separated from each other by a circumferential perforated partition 17. Due to the perforation of the partition 17, the extinguishing agent chamber 16 and the containment chamber 18 are in permanent fluid-flow communication.

[0055] In the operational state of the extinguishing device 10, the extinguishing agent compartment 16 and the barrier fluid compartment 18 are filled with a liquid, in particular water. The liquid located in the extinguishing agent compartment 16 is the extinguishing agent, and the liquid located in the barrier fluid compartment 18 is the barrier fluid.

[0056] The extinguishing agent chamber 16 is fluidically separated from the inner chamber 4 by a membrane 8. This membrane 8 forms almost the entire base of the cylindrical extinguishing agent chamber 16. A container with compressed gas 14 is arranged above the container 12. The compressed gas present in the container 14 has a pressure of at least 5 bar relative to normal atmospheric pressure. The container 14 can be fluidically connected to the container 12 via a pressurized gas line. For this purpose, a quick-acting valve 15 is located within the pressurized gas line. By opening this quick-acting valve 15, it is possible to introduce pressurized gas from the container 14 into the extinguishing agent chamber 16 of the container 12.

[0057] The pressure surge exerted on the extinguishing agent in the extinguishing agent chamber 16 destroys the membrane 8, and the extinguishing agent enters the inner chamber 4 under overpressure. The extinguishing zone L is located in the inner chamber 4.

[0058] After the extinguishing agent has entered the inner chamber 4 through the ruptured membrane 8, the barrier fluid flows from the barrier fluid chamber 18 through the perforations of the perforated partition 17 into the extinguishing agent chamber and, correspondingly, also through the ruptured membrane into the inner chamber 4. The barrier fluid also flows into the outer chamber 6 through the bottom opening, which connects the inner chamber 4 to the outer chamber 6. All remaining fluid in the extinguishing device, i.e., the barrier fluid and any remaining extinguishing agent, forms a liquid level. The volume of the barrier fluid is such that the barrier fluid alone already forms a liquid level that lies above the bottom opening of the inner chamber 4. An identical liquid level is thus formed in the inner chamber 4 and the outer chamber 6.This exceeds the bottom opening of the inner chamber 4, which means that any gas flowing into the extinguishing device 10 must necessarily pass through the liquid. This results in the barrier effect of the sealing liquid against a further flame front.

[0059] Container 12 now contains no liquid, apart from any remaining residual amounts. Accordingly, container 14 also no longer contains any compressed gas. In other words, further extinguishing using the extinguishing device is no longer possible. However, this is also unnecessary due to the sealing effect of the barrier fluid.

[0060] To restore the extinguishing device to a functional state, the sealing fluid can, for example, be drained via a draining device 23. Subsequently, only the damaged diaphragm 8 needs to be replaced, the container 12 refilled with liquid, and the container 14 refilled with pressurized gas. Alternatively, the empty container 12 and the empty container 14 can be replaced with filled ones.

[0061] Fig. Figure 2 shows the extinguishing device 10. Fig. Figure 1 shows a perspective view. The inlet flange 22 and the outlet flange 20 for connection to the gas line 2 are visible. Also visible is the cylindrical container 12, in which the extinguishing agent compartment 16 and the sealing liquid compartment 18 are arranged. The extinguishing agent compartment can be fluidically connected to the container 14 via a pressurized gas line, which has a quick-acting valve 15. The container 14 contains a compressed gas. It can also be seen that the extinguishing device 10 has a lid 25 and a base 27, each of which is connected via a lid flange 24 and a base flange 26 to a cylindrical housing containing the inner chamber 4 and the outer chamber 6.

[0062] Preferably, the container 12 and the container with the compressed gas 14 are permanently connected to the lid 25. This makes it possible, in particular, to restore the operational capability of the extinguishing device 10 by replacing the lid 25 together with the container 12 and the container 14. For this purpose, the diaphragm 8 is preferably arranged centrally in the lid 25. The lid flange 24 preferably has a recess corresponding to the diaphragm 8. In this way, it is particularly possible to replace even a damaged diaphragm 8 by replacing the lid 25. Work inside the extinguishing device 10 can then be avoided.

[0063] Fig. Figure 3 shows the extinguishing device 10 from the Fig. 1 and Fig. 2 in the integrated state within a gas pipeline 2. Unlike in Fig. 1 is at the in Fig. Figure 3 shows the extinguishing device 10 with the supply flange 22 on the left and the discharge flange 20 on the right. Gas passes through the extinguishing device 10 in Fig. 3 consequently from left to right, a flame front in the opposite direction, i.e. from right to left. Fig.Figure 3 shows that the extinguishing device 10 is connected to a supply section 19 of the gas line 2 via a flange corresponding to the supply flange 22. The discharge flange 20 is connected to a discharge section 21 of the gas line 2 via a corresponding flange. Detectors 28 are arranged in the supply section 19 of the gas line 2. These detectors are assigned to the extinguishing device 10 and are configured to detect a flame front. These are, for example, spark detectors. The detectors 28 send detector signals, which encode, for example, a detected spark or a detected flame front, to an electronic control unit 30. Based on these detector signals, the electronic control unit 30 controls the quick-switching valve 15.For example, if one of the detectors 28 detects a flame front in the gas line 2, it sends corresponding detector signals to the electronic control unit 30. This then controls the quick-switching valve 15 and opens it. The time of this opening is determined, for example, by the distance of the respective detector 28 from the extinguishing device 10. Opening the quick-switching valve 15 initiates the extinguishing process described above. Reference symbol list 2 Gas pipeline 4 Inner space 6 Outer space 8 Membran 10 Extinguishing device 12 containers 14 containers of compressed gas 15 Quick-switching valve 16 Fire extinguishing agent room 17 Perforated partition 18 Barrier fluid compartment 19 Supply section 22 Supply flange 21 Derivative section 20 Drainage flange 23 Drainage device 24 Cover flange 25 lids 26 Bottom flange 27 Floor 28 Detector 30 Electronic control L Extinguishing area S Restricted area

Claims

[1] Method for extinguishing a flame front in a gas pipeline (2) wherein the method comprises the steps: (a) Introducing an extinguishing agent under overpressure into an extinguishing area (L) of the gas pipeline (2), and furthermore (b) Introducing a sealing liquid into a sealing area (S) of the gas pipeline (2) such that the sealing liquid remains in the sealing area (S) in such a way that any gas flowing through the gas pipeline (2) must flow through the sealing liquid in the sealing area (S), characterized by , that the sealing liquid is introduced into the gas line (2) after the extinguishing agent. [2] Method according to claim 1, characterized by , that the barrier fluid introduced into the barrier area (S) prevents a flame front from moving from one side of the barrier area (S) to the other side of the barrier area (S). [3] Method according to any of the preceding claims, characterized bythat the extinguishing agent is simultaneously the sealing fluid. [4] Method according to any of the preceding claims, characterized by that the extinguishing area (L) and the exclusion area (S) coincide spatially at least partially, in particular one of the areas (L, S) is completely part of the other area (S, L). [5] Method according to any of the foregoing claims, characterized by , that to introduce the extinguishing agent into the extinguishing area (L) a closure is opened, in particular a valve is switched or a diaphragm (8) is destroyed. [6] Method according to any of the foregoing claims, characterized by , that the overpressure destroys a membrane (8) which fluidically separates the extinguishing agent from the extinguishing area (L) in order to introduce the extinguishing agent into the extinguishing area (L). [7] Extinguishing device (10) for a gas pipeline (2), wherein the extinguishing device (10) has at least one container (12) for receiving extinguishing agent and sealing liquid and is configured to carry out a method according to one of the preceding claims. [8] Extinguishing device Claim 7, characterized by that the extinguishing device (10) has a container (14) with compressed gas or a gas generator for generating the overpressure. [9] Extinguishing device according to claim 7 or 8, characterized by , that at least one container (12) is provided for receiving the extinguishing agent and the barrier liquid, wherein the container (12) preferably has at least one extinguishing agent compartment (16) and at least one barrier liquid compartment (18), which are preferably fluidically connected or can be connected. [10] Extinguishing device according to any one of claims 7 to 9, characterized by, that the extinguishing agent and the barrier fluid can be triggered separately from each other, i.e., introduced into the extinguishing area or the barrier area. [11] Extinguishing device according to any one of claims 7 to 10, characterized by , that the extinguishing device has at least one detector (28) for arrangement in the gas line (2), wherein the detector (28) is configured to detect a flame front and wherein the extinguishing device (10) has an electronic control (30), in particular an electronic data processing device, which is configured to carry out the method according to one of claims 1 to 6 depending on detector data of the at least one detector (28).

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