Definition Purpose Process Definition Lyophilization is another word

冷凍乾燥機設計理論 Definition Purpose Process

Definition Lyophilization is another word for freeze drying derived from the Greek words “solvent-loving. ” Lyophilized material is easily rehydrated. Freeze Drying is the process of removing moisture from a frozen product using vacuum.

Definition Sublimation is the freeze drying process in which solvents, such as water, pass directly from the solid to the vapor state. The rate of sublimation is dependent on temperature and pressure.

Purpose Freeze Drying preserves the integrity of the product’s biological and chemical structure and activity.

Process Prefreezing Primary Drying Secondary Drying

Pre-freezing Slant Freezing Gives more surface area to decrease freeze dry time. Preferred method. Stub Freezing Limited surface area. Not the preferred method to pre-freeze.

Pre-freezing Shell Freezing Increases the surface area to volume ratio by spreading out the frozen product inside the vessel.

Primary Drying Process Requires: Prefrozen sample. Temperature difference between sample and collector establishes a vapor pressure differential. (collector should be 15 -20° colder than the sample. Heat applied to the sample. High vacuum.

Primary Drying Cross Section View of Valve and Flask Frozen Sample Water Vapor Heat

Primary Drying A Vacuum Pump encourages the free flow of water molecules from the product by evacuating the environment around the product. It removes noncondensable gases. • Minimum Requirement -. 133 m. Br

Endpoint Determination The endpoint of primary drying can be determined by: Visual inspection. (cake or powder) Measurement of condensable gasses via vacuum gauge. Product temperature or weight.

Secondary Drying The process of reducing the 7 - 8% residual moisture content still present in the visually dry sample.

Secondary Drying Isothermal desorption is the removal of bound water from a sample. Requires a temperature higher than ambient and 1/3 -1/2 the time necessary for primary drying.

Bulk Tray Dryer An economical alternative to the Stoppering Tray Dryer when stoppering under a vacuum is not required. Lyophilize bulk samples such as soil, liquids or plant materials.

Bulk Tray Dryer 3 large shelves for bulk trays or batches of serum bottles, vials or ampules. 200 -watt heater on each shelf heats from – 20° C* to 60° C. LCD display of set point and temperature (C°) for each shelf. *Shelves are not cooled by the Bulk Tray Dryer. The only cooling is from the frozen sample.

Bulk Tray Dryer Vacuum release valve user to open the door. allows Option to purchase with or without six-port support shelf Option to purchase two additional heated shelves

Bulk Tray Dryer Accessories Support Shelf with valves installed provides flexibility to connect flasks and other freeze dry glassware. It also elevates Tray Dryer above work surface of Freeze Dry System to allow unobstructed access to the collector. Left: Heated Shelf With Sensor Right: Stainless Steel Bulk Tray