Abstract: Control of temperature of the shelves in a freeze dryer compartment is achieved by circulating a cooled heat transfer fluid from a heat exchanger through a vacuum condenser independently of circulating the cooled heat transfer fluid either directly through the passageway chambers in the freeze dryer shelves, for cooling the shelves, or through a heater for heating the shelves. These circulations are effected by the selective control of electrically operated valves in fluid conduits automatically by a programmed computer.

Abstract: A condenser for removing vapor from freeze dryers and other vessels includes a three-stage cyclonic or turbine-like vapor distributor mounted for rotation about the axis of an elongated horizontal delivery tube extending through the axial center of the condenser chamber. The delivery tube mounts end and radial spray nozzles for selectively spraying cleansing fluid and sterilizing steam onto the interior surfaces of all components within the condenser chamber, including a plurality of condenser members arranged in radially offset configuration about the delivery tube in an optically dense configuration which requires vapors to impact the cold surfaces of the condenser members before contacting the inner surface of the enclosing condenser chamber. Optical density is achieved by providing the condenser member as sheets of metal formed with a serpentine passageway between them for the circulation of a coolant.

Abstract: The access door of a chamber housing opening is secured releasably in closed position by a latching mechanism provided on each of the four edges of the door. Each latching mechanism includes a plurality of spaced apart wedges projecting outwardly from the edge of the door for releasable registry with a plurality of spaced apart wedges on a wedge member mounted on the chamber housing for movement by an hydraulic cylinder between a door opening position in which the wedges on the door register with spaces between the wedges on the wedge member, and a door latching position in which the wedges on the wedge member are moved by the hydraulic cylinder into sliding, wedging engagement with the wedges on the door, whereby to draw the door into sealing engagement with the chamber housing adjacent the periphery of the opening in the housing. An O-ring seal disposed about the periphery of the door is arranged to engage the chamber housing upon closure of the door, to seal the chamber for evacuation or pressurization.

Abstract: The shelf-operating piston rod of an hydraulic cylinder of a freeze dryer is prevented from possibly contaminiating the freeze dryer chamber either by isolating the piston rod from the chamber by enclosing the piston rod within the chamber with an impervious flexible sleeve capable of extending and retracting with the piston rod. The pressure within the sleeve may be adjusted to approach or match the pressure within the freeze dryer chamber. Prevention of contamination alternatively may be achieved by interposing a sterilizing container between the external hydraulic cylinder and the freeze dryer and surrounding the piston rod, and subjecting the piston rod within the sterilizing container to sterilizing fluid before the piston rod is extended into the freeze dryer chamber.

Abstract: A housing contains a plurality of vertically spaced shelves movable vertically relative to each other upon activation of a fluid pressure piston-cylinder unit mounted on the housing. Elongated suspension rods depend from the top shelf to support the next two adjacent shelves for relative vertical movement, and each subsequent lower shelf is similarly supported by a shelf above it but separated from it by one intervening shelf. The two top-most shelves also are arranged to be secured together detachably in abutting relationship. The lower end of each suspension rod mounts a rotary disc which supports a pair of upstanding spaced pins arranged in one position of rotary adjustment to abut the underside of a lug extending laterally from the adjacent shelf, and in a second position of rotary adjustment, 90.degree. from the first position, to register with openings in the lug, whereby the associated shelf is lowered from the first position of support a distance substantially equal to the length of the support pins.

Abstract: The main door of a freeze dryer is provided with a sub-opening arranged to register with the space between adjacent vertically adjustable freeze dryer shelves, for infeeding and outfeeding trays or other containers of material to and from each shelf. An entry chamber surrounds the sub-opening and has a sloping outer face provided with a resilient seal arranged to form a pressure tight seal with a sub-door movable by a fluid pressure piston-cylinder unit between positions opening and closing the entry passageway of the entry chamber. Photoelectric safety mechanism is associated with the entry passageway to prevent closing of the sub-door when any object is in the entry passageway.