Patent Application
20190314658
The present invention relates to a device that may be placed on or adjacent a fire to extinguish it, particularly a fire associated with rechargeable cells, or batteries or various chemistries, including but not limited to consumer electronics and automotive batteries.
When improperly handled, manufactured or overcharged, lithium-ion batteries are subject to thermal runaway i.e. the battery spontaneously increases in temperature and begins to vent hot and toxic pressurized gases. This causes the lithium ion fluid inside of the battery to ignite which can reach temperatures in excess of 2,000 degrees Fahrenheit. While it is possible to extinguish the flames by applying large amounts of water, the lithium inside the battery may react with the electrolytes and the water to generate hydrogen which can accelerate the fire. Sand or other granular minerals may be applied to a lithium battery fire; however, these minerals are only fire resistant and do not possess fire extinguishing properties. Accordingly, the application of these minerals to a lithium battery fire have been found to be unreliable, ineffective or impractical.
A fire occurring on an aircraft can be catastrophic for obvious reasons. The smoke and toxic vapors can create panic within the passenger cabin. It is imperative to quickly extinguish such fires. Current FAA guidelines recommend the use of water to extinguish a lithium battery fire. However, a sufficient quantity of water is not easily obtained on an aircraft during a flight nor can it be quickly and effectively applied to a fire. Although conventional fire extinguishers are available on an aircraft, they are limited in their effectiveness when applied to lithium battery fires.
Lithium battery fires are also problematic in the electronic industry, especially where large numbers of Li batteries, cells and personal electronic devices are collected, stored, recycled or repaired. It is known to dump scoops of sand or similar minerals onto a lithium battery fire in a laboratory setting, however the low porosity of the sand renders it an ineffective insulator of heat and it is useless to contain smoke and vapor. Furthermore, dumping or throwing sand onto a fire tends be haphazard and inefficient in practice and requires large quantities of sand be applied to the fire
UN rated boxes and packages for the purpose of shipping, both domestically and internationally, lithium batteries or cells of various states of damage, charge or chemistry, require the packaging to be absorbent and provide a non-combustible filler or cushioning material. Historically, the absorbent and non-combustible material used is vermiculite. However, the use of vermiculite is disadvantageous due to complexity of the material itself including the dust associated with loose fill vermiculite. Further, this material lacks fire suppression and extinguishing properties.
A need has therefore existed for a device that will quickly and easily enable any user, without training, to effectively extinguish a fire, especially a fire caused by a lithium battery. A need has also existed for inserts or liners for use within containers for shipping lithium batteries or cells in various states of damage, charge or chemistry that have superior cushioning and fire suppression/extinguishing characteristics.
The invention is a device for extinguishing a fire, the device comprises a pad adapted to be configured in various shapes and sizes and having a body or core filled with free-flowing expanded glass granulate having fire extinguishing properties, the body or core is compartmentalized to separately contain the free flowing granulate within defined regions, the body or core is formed from a sacrificial material that disintegrates upon exposure to heat whereby the free-flowing expanded glass granulate contained in the body or core is released onto the fire or source of heat to extinguish it. In one embodiment, the device includes a fire resistant cover member. In another embodiment one side or face of the device is provided with a fire resistant layer or barrier so that only an opposite side or face of the device is exposed to a fire during use.
A device for extinguishing a fire, the device comprises a body, the interior of the body is filled with free-flowing expanded glass granulate having fire extinguishing properties, the interior of the body having at least two compartments to separately contain the free flowing granulate within defined regions of the body, the body is formed from a material adapted to disintegrate when exposed to heat whereby when the device is placed on a fire the free-flowing expanded glass granulate contained in the compartments is caused to be released.
The protective cover 2 has a top 8, bottom 10 and sides 12. As best shown in
The body or core member 4 that contains the loose-fill granulate is constructed from a heat sensitive material that is combustible and will disintegrate when exposed to a flame or high heat. In a preferred embodiment the body or core member is constructed from a 100% polyester fabric coated with a PVC resin to increase its sensitivity to heat and flame. Other flammable fabrics and materials (e.g. cotton) are within the scope of the invention.
As best shown in
While it is preferred that the body have at least two compartments to separate and uniformly distribute the free flowing granulate, the invention can function without compartments. As noted earlier, the body or core may be variable in size depending upon its end use. A typical size for use on an aircraft for purposes of suppressing and extinguishing a battery fire in a personal electronic device will be approximately twenty four inches square with a thickness of about two inches.
The compartments 16 of the body or core 4 are filled with free flowing expanded glass granules. The granules are relatively small, lightweight spheres of expanded (i.e. foamed) silicon dioxide glass having interior pores that provide a closed cell structure. The granules readily absorb any heat and smoke and actively extinguish a fire by displacing oxygen and melting onto the ignited battery or device. The size of the aggregate correlates to the interior pore size and hence its relatively low density that enhances its utility as a reactive extinguisher. A commercially available expanded glass granulate suitable for use in the present invention is sold by Dennert Poraver GmbH under the EXTOVER trademark, which is incorporated herein by reference. The amount of expanded glass granulate provided in each compartment is an amount sufficient to substantially fill the compartment. As is apparent, it is within the scope of the invention to provide a lesser amount of granulate.
The size of the expanded glass granulate in the present invention is preferably non-uniform and comprises a blend of different size granules. The smallest size granules have relatively greater density and a smaller pore size while the largest sized granules have the lower density and a larger pore size. In a preferred embodiment, the size of the loose fill granulate is between about 1 mm diameter to about 4 mm in diameter. A suitable composition for the granulate is a blend of 1 mm, 2 mm, 3 mm and 4 mm diameter size spheres combined in a 1:1:1:1 ratio. The preferred blend has a total air content of about 80% by volume and an average density of about 10 bs/ft{circumflex over ( )}3 to promote sufficient absorption of the liquid electrolyte in an ignited battery, provide enhanced insulative properties from the heat of the fire and also provide low heat transference. The intense heat generated by the lithium battery fire causes at least some of the granules to melt which encases the battery as the fire is smothered and extinguished.
The use of compartments 16 within the body or core member 4 to individually retain the free-flowing granulate provides multiple functions. It to evenly distribute the granulate 6 throughout the body or core 4 and maintains its shape and structure and prevent excessive accumulation of the free flowing granulate within any single area of the body or core. Without the compartments the body or core can be too flexible and amorphous and not maintain a desired thickness and thus, in some instance, not release the granules on a fire in a controlled and evenly distributed manner. Compartments that are not sufficiently heated to release the granules during a fire event remain unopened and serve to provide ballast to keep the device on the fire and ensure the perimeter of the fire is surrounded by protective granulates in the event the fire reignites.
As noted earlier, a fire resistant protective cover 2 may optionally be provided in combination with the body or core member 4. The cover provides a barrier or protection from heat and flames when the device is placed on a fire and it also ensures the bottom face 10 of the body or core is directly exposed to the fire. The cover may also function to assist in retaining loose fill granulate that has been released from the body or core onto a fire. Due to its fire-resistance characteristics, the protective cover is reusable following a fire event. A new body or core may be placed within the cover so that it is ready for reuse.
In the event of a fire on an aircraft of within a laboratory including a fire generated by a lithium battery or electronic device powered by a lithium battery, the device D is simply placed over the ignited battery or electronic device to suppress the fire and extinguish it. If the device D includes the fire resistant cover, the bottom side 10 of the cover 12 is placed on the fire so that the body or core member 4 will be directly exposed to the fire. The sacrificial nature of the body or core 4 enable it to disintegrate from the heat of the fire and thereby release the expanded glass granulate directly on the fire in an unrestricted manner. The expanded glass granulate absorbs gas and smoke generated by the fire including any electrolyte and eventually extinguish the fire.
While this invention has been described as having a preferred design, it is understood that it is capable of further modifications, uses and adaptations, both in whole and in part, while following the general principle of the invention and including such departures from the present disclosure as is known or customary practice in the art to which this invention pertains, and as may be applied to the central features of this invention.
This application claims the benefit of priority from U.S. Provisional Application Ser. No. 62/658,729, filed on Apr. 17, 2018, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62658729 | Apr 2018 | US |
