摘要 |
Reusable pressurized containers are disclosed for dispensing fluids from the container without release of the pressurized propellant to the surrounding environment. The propellant is contained in a sealed, flexible compartment positioned within the container as a mixture of gas and liquid under pressure in equilibrium at the temperature of the container. A pressure transfer liquid, such as water or compressed air, is used to liquefy the propellant in the compartment. The pressure transfer fluid also contacts the fluid or semi-solid to be dispensed and exerts pressure thereon to force the fluid to be dispensed out of the container. The liquefied propellant, as it vaporizes, maintains the pressure against the pressure transfer fluid essentially constant. The propellant in the flexible compartment is preferably a mixture of a liquefiable propellant gas or blend thereof and a non-liquefiable inert gas such as nitrogen or helium.
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