Methods and systems for suppressing pyrophoric metal fires

Patent metadata

Field	Value
Publication number	US-9833648-B2
Application number	US-201414579512-A
Country	US
Kind code	B2
Filing date	Dec 22, 2014
Priority date	Dec 22, 2014
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A method for suppressing a pyrophoric metal fire may include arranging a suppression system above a containment structure. The suppression system includes a first extinguishing agent. The containment structure is configured to contain and isolate a pyrophoric metal from ambient air. The suppression system is configured to activate upon a leak and ignition of the pyrophoric metal so as to release the first extinguishing agent to suppress the pyrophoric metal fire.

First claim

The invention claimed is:

1. A method for suppressing a pyrophoric metal fire, comprising:
arranging a suppression system above a containment structure, the suppression system including a first extinguishing agent, the containment structure configured to contain and isolate a pyrophoric metal from ambient air, the suppression system configured to activate upon a leak and ignition of the pyrophoric metal so as to release the first extinguishing agent to suppress the pyrophoric metal fire, the suppression system configured such that a structural integrity thereof degrades in a presence of the pyrophoric metal fire in order to release the first extinguishing agent.

2. The method of claim 1 , wherein the structural integrity of the suppression system is configured to deteriorate when a surface of the suppression system reaches an elevated temperature as a result of exposure to the pyrophoric metal fire.

3. The method of claim 2 , wherein the structural integrity of the suppression system is configured to break down when the elevated temperature at the surface of the suppression system reaches 75 degrees Celsius or more.

4. The method of claim 1 , wherein the structural integrity of the suppression system is configured to deteriorate when exposed to one or more reaction byproducts of the pyrophoric metal fire.

5. The method of claim 4 , wherein the structural integrity of the suppression system is configured to become embrittled when the one or more reaction byproducts includes hydrogen gas.

6. The method of claim 5 , wherein the structural integrity of the suppression system is configured to break down when a concentration of the hydrogen gas reaches 50 pphm or more.

7. The method of claim 1 , wherein the arranging includes positioning the suppression system such that the first extinguishing agent falls on the pyrophoric metal fire via gravity when released.

8. A method for suppressing a pyrophoric metal fire, comprising:
arranging a suppression system above a containment structure, the suppression system including a first extinguishing agent, the containment structure configured to contain and isolate a pyrophoric metal from ambient air, the suppression system configured to activate upon a leak and ignition of the pyrophoric metal so as to release the first extinguishing agent to suppress the pyrophoric metal fire, the suppression system configured as a polymer layer including the first extinguishing agent, the polymer layer being applied on a ceiling above the containment structure.

9. The method of claim 8 , wherein the polymer layer includes the following structure

wherein X is a chlorine or a carbonate.

10. The method of claim 1 , wherein the suppression system is configured as a metal casing that encloses the first extinguishing agent therein.

11. The method of claim 10 , wherein the metal casing is configured as a partial-cylindrical container and secured to a bottom of an I-beam structure.

12. The method of claim 10 , wherein the metal casing is configured as a tubular container and secured to a ceiling above the containment structure.

13. The method of claim 10 , wherein the metal casing is formed to include defects and is infused with hydrogen diffusion promoters.

14. The method of claim 10 , wherein the metal casing includes a photodetector installed therein, the photodetector configured to indicate whether there is degradation of the metal casing by detecting whether light is entering the metal casing.

15. The method of claim 10 , wherein the first extinguishing agent is a salt-based powder or a graphite-based powder.

16. The method of claim 15 , wherein the first extinguishing agent includes a weak acid.

17. The method of claim 1 , wherein the pyrophoric metal is an alkali metal.

18. The method of claim 17 , wherein the alkali metal is sodium.

19. The method of claim 1 , further comprising:
spraying the pyrophoric metal fire with a second extinguishing agent.

Assignees

• Ge Hitachi Nuclear Energy Americas Llc

Inventors

• Loewen Eric Paul
• Dooies Brett Jameson
• Strege Seth Ryan Paul
• O'Neill Nicholas Francis
• Miranda Dana Christine
• Cowen Haley Michelle

Classifications

• G21C1/03 Primary

  cooled by a coolant not essentially pressurised, e.g. pool-type reactors · CPC title

• A62C3/06 Primary

  of highly inflammable material, e.g. light metals, petroleum products · CPC title

• Y02E30/40

  Cross-Sectional Technologies · mapped topic

• G21C17/0255

  Liquid metal leaks detection (detecting leaks in pipe-line systems in general F17D5/00) · CPC title

• G21C9/002

  against Na- or Ka- reactions · CPC title