Refrigeration – Processes – Treating an article
Reexamination Certificate
1999-07-02
2001-01-09
Capossela, Ronald (Department: 3744)
Refrigeration
Processes
Treating an article
C062S046100, C062S054100, C062S384000
Reexamination Certificate
active
06170269
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the freezing of products using liquid nitrogen and carbon dioxide snow, and in particular to the creation of frozen granules of the product using both liquid nitrogen and carbon dioxide snow.
BACKGROUND
Cryopreservation and cryoprocessing of mediums such as biopharmeceuticals and foods are important in the manufacturing, use, and sale of these products. However, in order to process many of these products, the cryopreservation or cryoprocessing must be done uniformly and in a controlled manner or the value of the product may be lost. For example, when processing cells for cryopreservation, if the cells are frozen too quickly with too high of a water content, then the cells will rupture and become unviable.
Uniformity can be achieved using small containers in which the volume of the medium in the container is small enough to allow it to be uniformly cooled. However, such small containers only allow small quantities of a product to be processed at one time, and thus are of limited commercial value. Additionally, as the size of the container is increased, the processing speed must be reduced in order to maintain uniformity in the processing.
One technique which has been used to cryoprocess foods in larger quantities is a system which mixes the product as it is frozen. Using traditional refrigerators or freezers during this process would take too long since the heat is extracted from the medium too slowly. Therefore, commercial systems have operated by spraying carbon dioxide snow on the product while it is mixed in order to rapidly cool it. Carbon dioxide snow, however, is a solid and therefore often makes less thermally conductive contact with solids in the medium and will not usually cool them quickly. This is beneficial for products which can be denatured if they are cooled too rapidly.
Liquid nitrogen is colder than carbon dioxide snow and can more quickly extract heat from a medium or product. Some commercial cryoprocessing systems have operated by spraying liquid nitrogen on the product or mixing the product with a liquid nitrogen mist. This allows for very rapid processing of a product and makes liquid nitrogen very useful in commercial cryoprocessing. Liquid nitrogen, however, may cool a product too quickly and can damage or destroy the usefulness of the product by, for example, denaturing it.
What is needed is a system and a method for cryoprocessing or cryopreservation of a medium or product which can make use of the properties of carbon dioxide snow and liquid nitrogen for cryoprocessing or cryopreservation of a medium or product without destroying its commercial utility.
SUMMARY OF INVENTION
One embodiment of the present invention is a system and method for freeze granulation of a medium such as a biopharmeceutical product. The medium is put into a chamber and mixed using a pair of counter rotating agitators. The agitators have angled blades or paddles on them in order to induce motion in the medium parallel to the axis of the agitator shafts. A set of liquid nitrogen and liquid carbon dioxide nozzles are attached to the chamber. The liquid nitrogen nozzles spray a mist of liquid nitrogen into the medium. The liquid carbon dioxide nozzles spray carbon dioxide snow into the chamber. The liquid nitrogen and the carbon dioxide can be sprayed into the chamber at the same time or alternately.
The liquid nitrogen mist and the carbon dioxide snow contact the medium when introduced into the chamber and the medium freezes. As the medium freezes the agitators mix the medium creating frozen granules of the medium.
Another embodiment of the present invention relates to a system for cryoprocessing or cryopresevation of a medium in a chamber. One embodiment of the invention comprises a chamber, a mixer, the mixer being housed within the chamber and coupled to the chamber. The chamber has a first input port for inputting carbon dioxide snow into the chamber. The chamber has a second input port for inputting a mist of liquid nitrogen droplets into the chamber. In other embodiments of the invention the medium is a biopharmeceutical product, a food product, or a biotechnology product.
In yet another embodiment of the invention, the mixer includes one or more agitators. In another embodiment of the invention, the agitators include a pair of counter rotating agitators. In other embodiments of the invention the mixer moving the material which first comes into contact with the carbon dioxide snow after the carbon dioxide snow is introduced into the chamber.
In still other embodiments of the invention, the mixer is a variable speed mixer, operates at different speeds, or with different agitators. In yet other embodiments of the invention the mixer is configured to create a flow of the medium about a perimeter of the chamber. In other embodiments of the invention second input port contains a nozzle which is configured to generate the liquid nitrogen mist wherein an average diameter of drops in the liquid nitrogen mist is less than 5 microns, 20 microns, 100 microns, or 1 millimeter.
In still other embodiments of the invention the carbon dioxide snow or the liquid nitrogen mist is input into the chamber at a rate which is controlled based on a feedback loop which monitors information including a load on the agitator, a temperature of the medium, or the temperature of the exhaust from the chamber. In still other embodiment of the invention a feedback loop controls a protocol by which the medium is. In other embodiments of the invention the chamber is connected to a bioreactor chamber, a processor, a feeder, a filtration system, or a reactor.
REFERENCES:
patent: 2879005 (1959-03-01), Jarvis
patent: 3214928 (1965-11-01), Oberdorfer
patent: 3393152 (1968-07-01), Smith et al.
patent: 3416977 (1968-12-01), Rein
patent: 4187689 (1980-02-01), Selcukoglu et al.
patent: 4265921 (1981-05-01), Lermuzeaux
patent: 4314451 (1982-02-01), Leeds et al.
patent: 4476686 (1984-10-01), Madsen et al.
patent: 4687672 (1987-08-01), Vitkovsky
patent: 4761962 (1988-08-01), Andersson
patent: 4843840 (1989-07-01), Gibson
patent: 4848094 (1989-07-01), Davis et al.
patent: 5135553 (1992-08-01), Rebhan
patent: 5154062 (1992-10-01), Gaumer, Jr. et al.
patent: 5205129 (1993-04-01), Wright et al.
patent: 5368105 (1994-11-01), Chaiken et al.
patent: 5728417 (1998-03-01), Horn et al.
patent: 5732559 (1998-03-01), Horn et al.
patent: 5743097 (1998-04-01), Frank
patent: 5964100 (1999-10-01), Wisniewski
patent: 2 041 341 (1992-10-01), None
patent: 3833753A1 (1989-08-01), None
patent: 0 560 509 A1 (1986-09-01), None
patent: 0 195 919 A2 (1986-10-01), None
patent: 0 711 511 A2 (1996-05-01), None
patent: 7-294085 (1995-11-01), None
Japanese Patent JP 07 294085 (Iwantani Ind. Co., Ltd.), Nov. 10, 1995 (Abstract), Database WPI Section PQ, Week 9603, Derwent Publications Ltd., London.
Abraham David J.
Capossela Ronald
Integrated Biosystems, Inc.
Wilson Sonsini Goodrich & Rosati
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