Hypoxic fire prevention and fire suppression systems with breathable fire extinguishing compositions for human occupied environments

Abstract

Fire prevention and suppression systems and breathable fire-extinguishing compositions are provided for rooms, houses and buildings, transportation tunnels and vehicles, underground and underwater facilities, marine vessels, submarines, passenger and military aircraft, space stations and vehicles, military installations and vehicles, and all other human occupied objects and facilities. The system provides a breathable hypoxic fire-preventative atmosphere at standard atmospheric or local ambient pressure. The system employs an oxygen-extraction apparatus supplying oxygen-depleted air inside a human-occupied area or storing it in a high-pressure container for use in case of fire. A breathable fire-extinguishing composition is introduced for constant fire-preventive environments, being mostly a mixture of nitrogen and oxygen and having oxygen content ranging from 12% to 17%. A fire-suppression system is provided employing a fire-extinguishing composition with oxygen concentration under 16%, so when released it creates a breathable fire-suppressive atmosphere having oxygen concentration of approximately 16% (or lower if needed) with possible addition of carbon dioxide. A technology for automatically maintaining a breathable fire-preventive composition on board a human-occupied hermetic object is provided by introducing inert ballast that automatically maintains oxygen content under the Hypoxic Threshold. An aircraft fire prevention and suppression systems are provided utilizing hypoxic fire extinguishing compositions for producing breathable atmosphere onboard having fire-retarding properties.

Description

[0001] This application is a continuation in part of U.S. Ser. No. 09 / 551026 "Hypoxic Fire Prevention and Fire Suppression Systems for computer rooms and other human occupied facilities", filed Apr. 17, 2000, U.S. Ser. No. 09 / 566506 "Fire Prevention and Fire Suppression Systems for computer cabinets and fire-hazardous industrial containers", filed May 8, 2000 and of U.S. Ser. No. 09 / 750801 filed Dec. 28, 2000 "Hypoxic Fire Prevention and Fire Suppression Systems and Breathable Fire Extinguishing Compositions for Human Occupied Environments".[0002] This invention is related in part to preceding U.S. Pat. No. 5,799,652 issued Sep. 1, 1998.[0003] The present invention introduces the method, equipment, and composition of fire prevention and suppression systems that utilize a low-oxygen (hypoxic) environment to:[0004] Instantly extinguish an ongoing fire[0005] Prevent a fire from getting started.[0006] With its mode of action based on the controlled release of breathable fire-suppressive...

AI Technical Summary

Benefits of technology

[0082] For example, air with a 4.51" (114.5 mm of mercury) partial pressure of oxygen at an altitude of 9,000' (2700 m) can easily support the burning of a candle or the ignition of paper.

[0272] At the present time new composite materials have allowed stronger and lighter aircraft to be designed without the need for reducing interior atmospheric pressure by pressurizing at higher altitudes. Such airplanes will provide a standard atmospheric pressure on board during the flight and can also handle a slight increase in internal pressure. A deployment of the AFSS on board of such aircraft will induce an average drop in arterial oxyhemoglobin from 98% to about 95%, which would be hardly noticeable by a passenger.

Problems solved by technology

Current fire suppression systems employ either water, chemicals agents, gaseous agents (such as Halon 1301, carbon dioxide, and heptafluoropropane) or a combination thereof Virtually all of them are ozone depleting, toxic and environmentally unfriendly.

Moreover, these systems can only be deployed post-combustion.

Once this fire-retarding gas is exhausted, a sprinkler system ensues that results in the permanent destruction of electronic equipment and other valuables.

Exposure to FM-200 and other fire-suppression agents is of less concern than exposure to the products of their decomposition, which for the most part are highly toxic and life threatening.

Consequently, there is no fire suppression / extinguishing composition currently available that is both safe and effective.

In terms of train, ship, or airplane fires, the inability to quickly evacuate passengers creates an especially hazardous situation.

In this case the problem was further compounded by the presence of ventilations shafts.

Originally designed to provide breathable air to trapped people, these shafts had the unfortunate side effect of dramatically accelerating the fire's propagation.

Especially devastating is the "chimney effect" that occurs in sloped tunnels.

In addition, ventilation shafts (which are present in virtually all multilevel buildings and industrial facilities) significantly increase the risk of toxic inhalation.

This problem is further compounded by the frequent presence of combustible materials that can dramatically accelerate a fire's propagation.

This system is severely limited for the following reasons:

The time that lapses between the outbreak of fire and the arrival of the Robogat is unacceptable.

The high temperatures that are characteristic of tunnel fires will cause deformation and destruction of the monorail, water and telecommunication lines.

The use of water and foam in high--temperature tunnel fires is only partially effective and will lead to the development of highly toxic vapors that increase the mortality of entrapped people.

One of the main safety deficiencies in modern passenger airplanes that still remains unresolved is a lack of proper firefighting and fire preventing equipment.

Although these and other chemicals are lethal, most victims die from carbon monoxide.

This color-and odorless gas produced in abundance during fires, especially in enclosed compartments with insufficient ventilation, is extremely lethal even in small concentrations of less than one percent.

The proliferation of toxic chemicals in modern advanced materials results in a cabin design completely made of plastics, fabrics, wiring and linings that can be extremely dangerous when they are heated sufficiently to produce gases.

Emergencies of various origins can lead to electric short-circuits with consequent inflammation of the insulating coat and surrounding flammable materials.

This is followed by a massive production of toxic aerosols, which pose the main hazard, according to human fire fatality experience.

While the most important survival systems for aircraft, such as gas turbines and fuel tanks are sufficiently equipped with automatic fire-fighting systems, the passenger cabin and cockpit critically lack fire-preventive means.

The use of standard fire-extinguishing substances, like Halon 2000 or the like, cannot resolve the problem, because of the high toxicity of the products of their pyrolysis.

A pilot's emergency checklist is too long to let the crew control fires in the air.

Moreover, these masks are practically useless against combustion's poisonous gases.

Furthermore, the oxygen supply in a passenger aircraft provides less than 20% of the oxygen flow required for respiration and lasts for only a few minutes.

Alternatively, increasing the fresh air supply, as offered in ECHO Air system of Indoor Air Technologies Inc. in Canada, will only propagate a fire and accelerate its lethality.

A recent study of the US Air Line Pilots Association (ALPA) suggests that in the year 1999, on average, one US airliner a day made an emergency landing because of a short circuit, which led to sparking, with resulting smoke and fire in the pressurized cabin.

Faulty wiring is the leading culprit.

In 1987, the US Navy ordered the removal of the most vulnerable wiring from its planes, and in 1999 NASA grounded its entire fleet of space shuttles when a wiring fault led to a launch being aborted.

Yet every day, millions of passengers are still carried by commercial aircraft that are equipped with old wiring that cannot be properly tested for faults.

In the wake of that crash, checks on other airlines around the world led to the discovery of several other airplanes in which the insulation on aging wiring leading to sensors in fuel tanks had rubbed away through vibrations, or had been damaged during routine maintenance.

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