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Sterilizer for culture media and laboratory ware
| Details |
Inventors: Perle, Abe J.; Freedman, David;
Assignee: New Brunswick Scientific Co., Inc. (New Brunswick, NJ)
Primary Examiner: Myhre; Charles J.
Assistant Examiner: O'Connor; Daniel J.
Attorney, Agent or Firm: Blum, Moscovitz, Friedman & Kaplan
A vessel, containing a culture medium or laboratory ware, is brought rapidly to sterilization temperature by circulating a mixture of steam and superheated water through a closely spaced jacket. The mixture of steam and superheated water is generated in a portion of the sterilizer which is exterior to the jacket and said mixture is circulated without the use of a pump. The sterilizer can be made in sizes small enough for bench-top operation and the sterilization procedure can be carried out with automatic control. |
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DETAILED DESCRIPTION In accordance with the present invention, apparatus for sterilizing a culture medium includes a vessel having a removable head which can be sealed thereto by an appropriate clamp.
The entire side and bottom of the vessel is surrounded by a close-fitting jacket spaced therefrom by a wire spiral.
A mixture of steam and water is supplied to the jacket by means of a gas-lift arrangement powered by electric heating coils.
The coils bring water to a boil in a small chamber at the bottom of a column and a mixture of water and steam rise through the column and enter the jacket near the top thereof.
The water than runs down the jacket in a spiral path, guided by the wire which separates the jacket from the vessel.
The jacket is fitted near the top thereof with a pressure-operated valve which opens when the internal jacket pressure reaches the operating limit, usually, 35 psig.
The valve thus serves the purpose of providing blow-off protection to the jacket and vessel during initial jacket filling from a higher pressure water service.
If also allows the by-pass of excess jacket water resulting from the volumetric expansion of the enclosed water upon heating.
By limiting jacket pressure to 35 psig, (136.
degree.
C), excessive heating rates of the contained medium are precluded by the limited temperature differential existing during the controlled sterilization cycle.
The dome is fitted with a vent which permits the passage of air but not of liquid.
As the vessel comes up to temperature, air in the solution and in the ullage above the liquid is vented.
When the system is cooled, air is allowed to enter the vessel through a hydrophobic filter which prevents the passage of water and of particles greater than about 0.
8.
mu.
, thereby preserving the contents from contamination by water droplets, bacteria or particulate-borne viruses.
The dome is also fitted with a motor stirrer holding a paddle for agitation of the solution.
The vessel is fitted at the bottom thereof with a dispensing valve through which sterilized solution can be drawn after the temperature of the system has been dropped, usually to about 46
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Heat Accumulators 
