Inert rendering method with a nitrogen buffer

• US 20030226669A1
• Filed: 12/23/2002
• Published: 12/11/2003
• Est. Priority Date: 01/11/2001
• Status: Active Grant

• Current Assignee: Wagner Group GmbH
• Original Assignee: Wagner Alarm- Und Sicherungssysteme GmbH
• Inventors: Wagner, Ernst Werner
• Granted Patent: US 7,156,184 B2
• Time in Patent Office: Days
• US Class Current: 169/45
• CPC Class Codes: A62C 99/0018 using gases or vapours that do not support combustion, e.g. steam, carbon dioxide

Abstract

The invention relates to an inert rendering method for preventing and/or extinguishing fires in enclosed spaces, wherein an oxygen-inhibiting gas is introduced into the target area in order to adjust a first basic level of inertion with a reduced oxygen content in comparison with natural conditions, and wherein an oxygen-inhibiting gas is further introduced in a gradual or sudden manner (in the case of a fire) into the target area in order to adjust one or more levels of inertion with a similarly reduced oxygen content. The invention also relates to a device for carrying out the method, comprising an oxygen-measuring device in the target area and a source of an oxygen-inhibiting gas. The aim of the invention is to provide an inert rendering method and device for carrying out said method enabling the storage of extinguishing gas needed to extinguish a fire in a simple, economical manner without having to resort to premises which are normally specially provided therefor.

Claims

1. An inert rendering method for preventing and/or extinguishing fires in an enclosed space (hereinafter called the“

target area”

), wherein an oxygen-inhibiting gas is introduced into the target area (10) in order to adjust a first basic level of inertion with a reduced oxygen content in comparison with natural conditions, and wherein an oxygen-inhibiting gas is further introduced in a gradual or sudden manner (in the case of a fire) into the target area (10) in order to adjust one or more levels of inertion with a similarly reduced oxygen content, is characterized by the following procedural steps;

a) In at least one enclosed buffer space (20, 20′

), which is connected to the target area (10) via supply lines (30, 30′

), a buffer gas volume (22, 22′

) is generated by introducing an oxygen-inhibiting gas. The oxygen content of the buffer gas volume is so low that when the buffer gas volume (22, 22′

) mixes with the ambient air (12) in the target area (10), a level of inertion with a similarly reduced oxygen content can be reached; and

b) in case of need, the buffer gas volume (22, 22′

) is guided, via the supply lines (30, 30′

), into the target area (10), where it is used, by mixing the ambient air (12) of the target area (10) with the buffer gas volume (22, 22′

), to adjust a level of inertion that differs from the first basic level of inertion.

2. A method, according to claim 1, wherein the level of inertion, which differs from the first basic level of inertion, is a second basic level of inertion with a similarly reduced oxygen content, or is the full level of inertion for the fire extinguishing operation.

3. A method, according to claims 1 or 2, is characterized by mixing the ambient air (12) of the target area (10) with the buffer gas volume (22, 22′

) in such a way that, on account of the specified quantity and concentration ratios of oxygen in both areas, an average oxygen concentration between 8 and 17 per cent by volume results in the target area (10), through which a possible fire is prevented or, as a result of a fire detection signal, a fire is extinguished.

4. A method, according to one of claims 1 to 3, wherein the oxygen content of the buffer gas volume (22, 22′

) in the buffer space (20, 20′

) is 10 per cent by volume or less.

5. A method, according to one of claims 1 to 4, wherein the buffer gas volume (22, 22′

) is composed of a pure inert gas or of mixtures of inert gases.

6. A method, according to one of the preceding claims, wherein, in case of need, the buffer gas volume (22, 22′

) of various buffers (20, 20′

), connected by valves (53) via a supply line (31), is guided into the target area (10).

7. A device for carrying out the method, according to one of claims 1 to 6, with

an oxygen measuring device (40, 40′

) in the target area (10); and

a source of an oxygen-inhibiting gas

is characterized by an enclosed buffer space (20, 20′

) that is connected to the target area (10) via gas supply lines (30, 30′

), and in which, by introducing an oxygen-inhibiting gas, a buffer gas volume (22, 22′

) is generated whose oxygen content is so low, that when mixing the buffer gas volume (22, 22′

) with the ambient air (12) in the target area (10), a full level of inertion for an extinguishing operation can be reached.

8. A device, according to claim 7, wherein the level of inertion, which differs from the first basic level of inertion, is a second basic level of inertion with a similarly reduced oxygen content, or is the full level of inertion for the fire extinguishing operation.

9. A device, according to claim 7 or 8, wherein the buffer room (20, 20′

) is designed as a container, particularly as a tank.

10. A device, according to one of the preceding claims, is characterized by a gas supply line (31) that connects the enclosed buffer spaces (21, 21′

) of the individual areas of a building and by means of which, in case of need, the buffer gas volumes (22, 22′

) of the individual areas are guided into the target area (10).

11. A device, according to one of the preceding claims is characterized by a valve unit (53) via which the supply line (31) is connected to the buffer rooms (21, 21′

) of the individual areas of a building.

12. A device, according to one of claims 7 to 11, is characterized by a mixing unit (50, 50′

) for mixing the ambient air (12) of the target area (10) with the buffer gas volume (22, 22′

)

13. A device, according to claim 12, wherein the mixing unit (50, 50′

) contains ventilation flaps (52, 52′

) and ventilators (54, 54′

) that are arranged in or at the target area (10).

14. A device, according to one of claims 7 to 13, is characterized by a control unit (60) for regulating the oxygen content in the target area (10) and having a signal transmitter (62) for switching from a first basic level of inertion to one or more, different basic levels of inertion.

15. A device, according to claim 14, wherein the control unit (60) also monitors the air quality of the ambient air (12) by measuring the CO and/or CO₂ content, and wherein the control unit activates the ventilation flaps (52, 52′

) and/or the ventilators (54, 54′

) for the supply of fresh air.

16. A device, according to claim 14 or 15, wherein the signal transmitter (62) gives a timing signal, a burglar alarm signal or an access control signal.

17. A device, according to one of claims 7 to 16, is characterized by a fire detector (70, 70′

) for triggering the mixing of the buffer gas volume (22, 22′

) with the ambient air (12) of the target area (10) in the fire extinguishing operation.