Dry chemical fire suppressant for a battery pack
A fire suppressant for cooling a battery pack includes a pressurized mixture of a dry chemical and carbon dioxide. The dry chemical is an inorganic particulate chemical. The dry chemical particles are small enough to be carried by a flow of depressurizing carbon dioxide. A mass of the dry chemical is between 5% and 50% of a mass of the carbon dioxide. The carbon dioxide, when depressurized, vaporizes and cools the dry chemical and the battery pack. The dry chemical can adhere to the battery pack when the mixture is depressurized. An amount of the fire suppressant used to cool the battery pack is equal to or greater than an inerting volume of fire suppressant for the battery pack.
1 . A fire extinguisher comprising:
a pressure vessel;
a dry chemical inside the vessel, wherein the dry chemical is an inorganic particulate chemical, and wherein a size of the particles of the dry chemical is between 1 micrometer and 100 micrometers;
carbon dioxide pressurized as a liquid inside the vessel; and
an inert gas pressurizing the vessel, wherein the inert gas pressurizes the vessel to a pressure higher than a vapor pressure of the carbon dioxide;
wherein the particle size of the dry chemical is small enough to ride on a stream of depressurizing carbon dioxide and inert gas.
2 . The fire extinguisher of claim 1 , wherein the inert gas is chosen from the group consisting of nitrogen, argon, helium, and combinations thereof.
3 . The fire extinguisher of claim 2 , wherein the inert gas is nitrogen, and wherein the nitrogen is at a pressure between 1000 PSIG and 1500 PSIG.
4 . The fire suppressant of claim 1 , wherein the dry chemical comprises:
sodium bicarbonate; and
silica;
coloring agents; and/or
moisture resistant coatings; and
wherein the sodium bicarbonate is at least 90% of the dry chemical.
5 . The fire extinguisher of claim 1 , wherein the dry chemical is sodium bicarbonate, and wherein particles of the sodium bicarbonate are between 1 micrometer and 50 micrometers.
6 . The fire extinguisher of claim 1 , wherein the dry chemical is potassium bicarbonate, and wherein particles of the potassium bicarbonate are between 5 micrometers and 50 micrometers.
7 . The fire extinguisher of claim 1 , wherein the dry chemical is monoammonium phosphate, and wherein particles of the monoammonium phosphate are between 10 micrometers and 50 micrometers.