摘要 |
A conventional cooker or retort for heat processing sealed containers, such as sealed pouches, jars or cans, has an evaporator associated therewith. A source of water is coupled to the evaporator through a valve and a source of a liquid having a higher vapor pressure than water, such as ethyl alcohol, is connected to the evaporator through a metering pump. Pressure and temperature within the retort are monitored and signals indicative thereof are connected to controllers for metering the heat supplied to the evaporator and for metering the ethyl alcohol and water delivered to the evaporator. One controller is configured to operate so that as pressure rises, proportions of ethyl alcohol introduced into the evaporator is reduced while the proportion of water introduced is increased. Another controller functions to restrict the amount of heating medium, such as steam, delivered to the evaporator as the retort temperature increases. In this fashion a predetermined pressure and temperature is maintained within the retort such that an overriding pressure is provided relative to the pressure within the sealed containers being processed.
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