Abstract: A method and an apparatus for effecting freeze-drying specimens containing solvents or condensing solvents having a shallow pan treatment chamber with little or no obstructions, holes or orifices. The treatment is effected by cooling the base of the chamber by using coolant-containing coils mounted beneath the base of the chamber. The direct thermal conduction of heat through the base of the chamber provides a more effective method of both cooling specimens and condensing solvents, typically water. A source of vacuum is provided to the chamber by a conduit located in the cover, sidewalls or base of the chamber. The method and apparatus may employ a moveable specimen holder positioned in the chamber. The moveable specimen holder may be mounted on a perforated tube which slidably engages a conduit in the base of the chamber. The perforated tube may a conduit to the source of vacuum.

Abstract: A device for positioning a probe, such as a temperature sensor, in a flask for freeze drying. The device includes a stopper adapted to be secured to an open end of the flask. The stopper has a center opening and at least one radial opening spaced from the center opening. The radial opening allows for fluid communication between inside and outside of the flask when the stopper is secured to the open end of the flask. The center opening receives a guide tube which extends into the flask and is sized to receive the probe such that substantially no fluid communication between the inside of the flask and the outside of the flask occurs through the guide tube or center opening. A channel formed in an upper surface of the stopper and an O-ring positioned about an outer diameter of a neck of the flask secure the probe in position relative to the guide tube. The multiple radial openings define an annular passageway which mimics fluid communication through a standard slit-type stopper employed in freeze drying.

Abstract: The present invention provides a high speed homogenizer which has an adjustable gripping means to grip and hold containers of varying size. This gripping and holding means can be centered or decentered under the homogenizing tool. Decentering a container held by the gripping and holding means tends to minimize or even eliminate vortexing problems. The homogenizer also has electronic means for controlling the speed and time of operation of the homogenizing tool. The electronic control means of the homogenizer can also monitor the temperature of the sample being homogenized and respond to changes in temperature when necessary. The homogenizer can be easily adjusted up and down a vertical support post by a counter weighting mechanism such as a constant force spring.

Abstract: The subject invention provides a freeze dryer apparatus having an interim condensing system, preferably a refrigeratable condensing surface. The interim condensing system condenses vapors within the product chamber of the freeze dryer apparatus when the main condenser coil, which normally condenses vapors within the product chamber, needs to be defrosted. The refrigeratable condensing surface is preferably mounted inside the product chamber.

Abstract: The circulation of heat transfer fluid through the low temperature heat exchanger in the temperature control system of a freeze dryer is selectively increased when the temperature of heat being applied to the product shelf assembly in the freeze dryer exceeds the desired temperature. Preferably, a servo-controlled mixing valve selectively bypasses the low temperature heat exchanger so that the rate of cooling is very precisely adjusted without requiring the heat exchanger refrigeration unit to be cycled on and off. Since the refrigeration unit operates continuously, the reliability and operating lifetime of the refrigeration unit is increased. Moreover, the heat exchanger temperature is maintained at a minimum value. Preferably, the servo-control for the mixing valve includes a digitally controlled stepping motor and the adjustment of the mixing valve is sensed by a linear voltage displacement transducer. To prevent short cycling and oscillation, a dead band is introduced in the servo-control loop.

Abstract: A condensation chamber for freeze drying apparatus is designed such that moisture containing air evacuated from a drying chamber passes substantially uniformly over the cooled interior surfaces of the condensation chamber thereby maximizing the available surface for moisture condensation and freezing. This desirable result is achieved by a tube which is connected to a vacuum pump and positioned through an end wall of the condensation chamber along the central axis of the chamber. One open end of the tube is positioned adjacent one end wall of the chamber and openings are provided through the wall of the tube adjacent the other end wall so that moisture containing air entering the chamber intermediate of the openings in the tube travel in both directions along the cooled interior surfaces of the chamber toward both openings in the tube.

Abstract: A shelf arrangement is disposed within the vacuum drying chamber of a freeze dryer. The shelf arrangement has multiple vertically-movable shelves that are suspended by stops on flexible wires stretched between upper and lower brackets of a frame assembly. Each shelf has four flanges extending from the edge thereof which comprise arms that straddle corresponding wires thereby engaging the stops so that the shelves are positioned in a vertical arrangement. The slots between the arms of the flanges allow the shelves to slide vertically along the wires when multiple screw members which engage following threaded nuts attached to the lower most shelf of the group of shelves are rotated. Thus, as the lower most shelf is raised, it engages the next highest shelf and so forth until all of the shelves are elevated vertically against the upper bracket.

Abstract: Disclosed is a door and hinge frame arrangement for external-pressure vessels or vacuum chambers which has a five-way adjustment capability to assure that the door properly seals over the chamber entrance without the necessity for the application of large forces. A chamber door (which may be either circular or square) is pivotally mounted in a vertical position between ends of horizontal arms of a "C" shaped frame assembly. The "C" shaped frame comprises a vertical hinge member which is pivotally mounted at the bottom and top ends thereof, and the two horizontal arms extend from opposite ends of the straight member. Thrust bearings are provided to support the weight of the door and frame at the lower pivot of the vertical member. The vertical position of the door and frame can be adjusted by varying the thickness of the thrust bearings at this point.