GB1054172A - - Google Patents

Abstract

1,054,172. Freeze drying apparatus. LEYBOLD - HOCHVAKUUM - ANLAGEN G.m.b.H. May 8, 1964 [May 10, 1963], No. 19355/64. Heading F4G. A freeze drying apparatus comprises a tank 1 spacedly housing a movable vessel 2 internally divided by a partition 5 with openings 21 into an upper drying chamber wherein the material 30 to be dried in bottles 9 is mounted on heated plates 8 on a removable carrier 11 and an openbottomed area encircling an ice condenser 16. The tank is evacuable by a connection 26 to a pump (not shown) and is closed by a hinged cover 3 for insertion and extraction of the carrier 11. The cover houses a pressure gauge 7 and a fan 4 which circulates air from tank 1 over the condenser, through the openings 21 in the partition 5 and non-aligned openings 21 in a closure plate 12 provided in the chamber above the partition, about the bottles 9 to freeze the material therein and then redelivers air through the space 32 between the vessel and tank back to the condenser. Relative movement between the tank and drying chamber is achieved by a vertically movable column 13 so that the plate 12 may rest on the partition 5 to prevent further circulation of cold air by isolating the drying chamber from the evacauting means and condenser. This allows heating of the material and evacuation of the chamber for sublimation and also allows the partition 5 and plate 12 to act as a radiation shield between the material and condenser.