Abstract: A chemical fire extinguishing apparatus which includes a chemical storage chamber, chemical discharge conduct connected to the chamber for conveying and distributing the chemical, and a source of relatively high pressure gas connected to the chamber and communicating with the interior thereof to agitate and fluidize the extinguishing chemical by impingement of high pressure gas. Upon agitation and fluidization, gas is delivered then to the chamber at a lower pressure to entrain the chemical in a constant, relatively low pressure gas stream flowing from the chamber to the chemical discharge conduit.

Abstract: A method and apparatus for venting cryogenic storage tanks. In the method, a non-flammable, non-combustion supporting, relatively warm gas is mixed with cold vapors vented from a cryogenic storage tank to warm the vented vapors to a characteristic density less than that of the air adjacent the tank. The apparatus employed includes a vent pipe having a Venturi ejection throat therein, a pressure relief valve spaced from the ejection throat, and a gas ejector nozzle extending into the vent pipe between the safety relief valve and the ejection throat.