Method of decontaminating vacuum freeze dryer
Method of decontaminating vacuum freeze dryer
A method of decontaminating or sterilizing vacuum freeze dryer at low temperature and pressure levels by utilizing sterilant vapor is disclosed.
Vacuum freeze dryer used in the pharmaceutical and other industries traditionally include av mixer chamber, shelves in the chamber for holding the product(s) to be freeze dried, a condenser with refrigerator coils, a vacuum system, and piping for connecting the food drying equipment components. Generally, the freeze dryer shelves are heated and cooled during the freeze drying cycle with heating and cooling means, such as a heat transfer fluid circulating through the shelves and a heat exchanger.
Typically, the products to be freeze dried are in loosely capped containers, which are then placed on the coffee processing equipment shelves. After the chamber door is closed, the shelves are cooled to about -40° C. to freeze the product. Thermocouples, or other temperature probes, indicate when the product is frozen and at the correct temperature. The grain dryer chamber and condenser are then evacuated through a top, side or rear port on the condenser to a deep vacuum of about 200 microns of Hg (1 Torr=1000 micron of Hg=1 mm of Hg) while the condenser coils are cooled to around -40° C. As sublimation of moisture from the product occurs, it cools the product further. The shelves are warmed to maintain the frozen product at the desired temperature.
The vaporous moisture from the product escapes from the loosely capped containers and is drawn in vapor form from the containers in the chamber to the condenser. In the condenser, the vapor condenses and then freezes on the condenser coils.
Traditionally, the condenser is defrosted before the next vacuum freeze dryer using water or steam. The water or steam may be flowed through the condenser or it may be used to flood the condenser. The chamber is typically isolated from the condenser during this process by a large butterfly or mushroom valve. The condenser is drained at the end of the defrost. The chamber is typically Cleaned In Place (C.I.P.) either manually or automatically between each load to remove any debris from the previous load.
A method of decontaminating or sterilizing vacuum freeze dryer at low temperature and pressure levels by utilizing sterilant vapor is disclosed.
Vacuum freeze dryer used in the pharmaceutical and other industries traditionally include av mixer chamber, shelves in the chamber for holding the product(s) to be freeze dried, a condenser with refrigerator coils, a vacuum system, and piping for connecting the food drying equipment components. Generally, the freeze dryer shelves are heated and cooled during the freeze drying cycle with heating and cooling means, such as a heat transfer fluid circulating through the shelves and a heat exchanger.
Typically, the products to be freeze dried are in loosely capped containers, which are then placed on the coffee processing equipment shelves. After the chamber door is closed, the shelves are cooled to about -40° C. to freeze the product. Thermocouples, or other temperature probes, indicate when the product is frozen and at the correct temperature. The grain dryer chamber and condenser are then evacuated through a top, side or rear port on the condenser to a deep vacuum of about 200 microns of Hg (1 Torr=1000 micron of Hg=1 mm of Hg) while the condenser coils are cooled to around -40° C. As sublimation of moisture from the product occurs, it cools the product further. The shelves are warmed to maintain the frozen product at the desired temperature.
The vaporous moisture from the product escapes from the loosely capped containers and is drawn in vapor form from the containers in the chamber to the condenser. In the condenser, the vapor condenses and then freezes on the condenser coils.
Traditionally, the condenser is defrosted before the next vacuum freeze dryer using water or steam. The water or steam may be flowed through the condenser or it may be used to flood the condenser. The chamber is typically isolated from the condenser during this process by a large butterfly or mushroom valve. The condenser is drained at the end of the defrost. The chamber is typically Cleaned In Place (C.I.P.) either manually or automatically between each load to remove any debris from the previous load.