Results 261 to 270 of about 91,141 (309)

Sublimation Freeze-Drying without Vacuum

Science, 1959
Analysis of the freeze-drying procedure shows that the passage of water vapor from the drying boundary through the dried shell is facilitated primarily by the vapor pressure gradient rather than by the absolute pressure of the system. This is experimentally confirmed, and a device for freeze-drying at atmospheric pressure is described.
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Freeze‐drying using vacuum‐induced surface freezing

Journal of Pharmaceutical Sciences, 2002
A method of freezing during freeze-drying, which avoids undercooling of a solution and allows growth of large, dendritic ice crystals, was investigated. Aqueous solutions of mannitol, sucrose, or glycine were placed under a chamber vacuum of approximately 1 mbar at a shelf temperature of +10 degrees C.
Martin, Kramer, Bernd, Sennhenn, Geoffrey, Lee   +2 more
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Freeze drying - vacuum sublimation

Journal of Scientific Instruments, 1951
A short account is given of the principles involved in the dehydration of heat sensitive materials by sublimation from the frozen state. References are made to drying rates and important design features of commercial apparatus.
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Rapid vacuum freeze‐drying of meat

Journal of the Science of Food and Agriculture, 1958
AbstractFreeze‐drying carried out in conventional equipment is a slow process, the rate of drying being limited by the rate of transfer of heat of sublimation. A method is described to carry out rapid freeze‐drying of meat or other foodstuffs by laying the pieces between heater plates fitted with metal spikes which conduct heat uniformly and ...
C. Brynko, W. R. Smithies
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Modeling of Vacuum Desorption in Freeze-Drying Process

Drying Technology, 2005
Abstract A mathematical model of multicomponent vacuum desorption, which occurs in vacuum freeze-drying process, was developed. In freeze-drying porous biomaterials and pharmaceuticals are considered and the vacuum freeze-drying process, especially the moisture desorption in its final stage, is investigated.
J. F. Nastaj, B. Ambrożek
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Preparation of Li2CO3 powder nanoparticles by vacuum freeze drying

Ceramics International, 2021
Abstract Decreasing the particle size of Li2CO3 powder is beneficial for advancing its applications in the manufacturing of different materials and drug delivery. Therefore, in this study, a novel bottom-up process based on freezing is proposed for the production of nanoparticles.
Wenfeng Mo, Weihong Lu, Jingtian Li, Junbin Sun, Mansheng Chen, Wenyi Li, Zhoulan Yin   +6 more
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EFFECTS OF HEATING METHODS ON VACUUM FREEZE DRYING

Drying Technology, 1997
ABSTRACT The heat and mass transfer during freeze drying of raw beef by different heating methods is studied theoretically and experimentally. The difference between radiant heating and microwave heating in freeze drying process has been analyzed. The results obtained are important for the selection of the heating methods in practical freeze dryers.
Zhao Hui Wang, Ming Heng Shi
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Vacuum techniques in freeze-drying pilot plants

Vacuum, 1967
Abstract Pilot plant scale operations are described in relation to the process requirements of the freeze-dried food industry. The principles of the freeze-drying process are outlined with examples of the currently available equipment and some techniques of product evaluation from the points of view of process economy and marketing feasibility.
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Vacuum Distillation and Freeze Drying

1979
Vacuum distillation is based on the fact that under vacuum the boiling point of the materials is lower than at normal atmospheric pressure. The use of vacuum distillation for distilling off solvents is required where elevated temperatures would destroy the resolved components. Working with some biologically active materials which are dissolved in water,
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VACUUM‐PUFF FREEZE DRYING OF TROPICAL FRUIT JUICES

Journal of Food Science, 1971
SUMMARY— A study was made to develop high Quality juice powders from four tropical fruits. Guava and mango puree, passion fruit and pineapple juice were dehydrated in a vacuum‐puff freeze‐drying process. Sucrose in amount (25–40%) approximating nectar formulations was mixed with single‐strength juice or puree ...
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