Pressure responsive conditioning control gas sterilization

Claim 1

Apparatus for conditioning goods for sterilization and sterilizing goods with a chemically biocidal gas, the conditioning including heating the goods to a selected temperature related to the desired sterilization temperature and moistening the goods to a desired level for such biocidal gas sterilization, with conditioning steps being free of temperature and moisture measurement requirement levels in the goods and chamber, comprising in combination a sealable chamber capable of operating at pressures other than atmospheric, means providing access for loading goods to be sterilized into the chamber and closing the chamber to permit operation at other than atmospheric pressure, means for evacuating the chamber, means for sensing pressure levels in the chamber, means for injecting a conditioning vapor comprising steam into the chamber, valve means for controlling injection of conditioning vapor into the chamber, said valve means being free of flow rate control adjustment capabilities, means for introducing a chemically biocidal gas, and control means electrically interconnected to activate and deactivate the means for evacuating the chamber, the valve means for controlling injection of conditioning vapor, and the means for introducing a biocidal gas, such control means being electrically connected to the means for sensing pressure level within the chamber and including timer means and sequencing means to evacuate the chamber to a preselected subatmospheric level responsive to such pressure level sensing means, then inject conditioning vapor to raise chamber pressure to a higher preselected subatmospheric pressure level responsive to such pressure level sensing means, then hold the chamber in sealed condition with evacuation and vapor injection interrupted for a predetermined time responsive to the timer means, then repeat such sequence of evacuating the chamber, injecting conditioning vapor, and holding the chamber in sealed condition, then add biocidal gas to raise chamber pressure to a desired pressure above atmospheric pressure responsive to such pressure sensing means, and hold such biocidal gas and conditioning vapor in the chamber a predetermined time responsive to the timer means to complete desired sterilization.