Low pressure storage of metabolically active material with open cycle refrigeration

• US 3,913,661 A
• Filed: 03/26/1974
• Issued: 10/21/1975
• Est. Priority Date: 01/05/1972
• Status: Expired due to Term

• Current Assignee: Dormavac Incorporated 274 Delaware AVE Buffalo NY
• Original Assignee: Stanley P. Burg, William J. Hentschel
• Inventors: Burg, Stanley P., Hentschel, William J.
• Primary Examiner(s): Davis, Jr., Albert W.
• Assistant Examiner(s): O'Connor, Daniel J.
• Application Number:
  US05/454,825
• Time in Patent Office: 574 Days
• Field of Search: 165/1,2,3,19,30,60,63 62/268,269,270 426/419 99/154
• US Class Current: 165/222
• CPC Class Codes: A23B 4/066 the materials not being transported through or in the apparatus with or without shaping, e.g. in the form of powder, granules or flakes
• CPC Class Codes: A23B 7/148 in a controlled atmosphere, e.g. partial vacuum, comprising only CO2, N2, O2 or H2O
• CPC Class Codes: A23L 3/3418 in a controlled atmosphere, e.g. partial vacuum, comprising only CO2, N2, O2 or H2O
• CPC Class Codes: A23L 3/363 the materials not being transported through or in the apparatus with or without shaping, e.g. in form of powder, granules, or flakes

Abstract

A controlled refrigerated storage environment conducive to preservation of stored respiring food tissue or other respiring matter is produced, without the use of closed cycle refrigeration, by expanding atmospheric air and raising its relative humidity by passing it through a body of water while heating the body of water (except when the cooling demand exceeds the cooling capacity of the equipment) so that the air is cooled by its expansion and by evaporation of said water only to a preservation-conducive temperature (higher than the capacity of the equipment with that pressure drop at that rate of flow in the absence of such heating) and flowing the cooled expanded watersaturated air around the stored matter to sweep away gaseous products of metabolic reaction emitted from said matter. Heat input to the water is made responsive to cooling of the air in the vacuum chamber below a preservation conducive temperature level and may be via an electric resistance element, e.g., immersed in the body of water, by heat exchange from an oil, water or air cooling system of a vacuum pump which serves as the air expansion means or from atmospheric air.

Claims

1. The method of open cycle conditioning of the interior of a closed chamber comprising flowing outside atmospheric air into the interior of said chamber while reducing its pressure and contacting it with a body of water to provide a cooling capacity consequent to expansion of said flowing air and evaporation of said water and, while maintaining both the rate of flow of air and pressure drop at selected constant values to provide cooling capacity in excess of that required to maintain the internal temperature of said chamber at a desired temperature, controlling the temperature of the flowing air in said chamber by heating said air and said body of water.

2. The method as claimed in claim 1 wherein the selected value of flow is sufficient to cause at least one change per hour of air in said chamber.

3. The method as claimed in claim 2 wherein the pressure has a value in the range of 25-400 mm Hg.

4. The method as claimed in claim 1 wherein the closed chamber contains green bananas and the internal temperature of the chamber is maintained at approximately 58*F.

5. The method as claimed in claim 1 wherein the temperature of the air in said chamber is controlled by heating said flowing air responsive to any drop in said internal temperature below said desired temperature.

6. The method of conditioning a storage chamber for preserving food, plants and the like comprising, maintaining sub-atmospheric pressure in said chamber, admitting air to said chamber and reducing the pressure of said air that flows into said chamber and expands, maintaining a supply of water, contacting said air and water, evaporating said water and humidifying said air, cooling the contents of said chamber by the expansion of said air and evaporation of said water, and heating said water.

7. The method of claim 6 with the step of maintaining a desired temperature in said chamber by balancing said cooling and heating.

8. The method of claim 6 with the step of exchanging heat between the air being admitted to said chamber and air leaving said chamber.

9. The method of claim 6 with the step of maintaining said sub-atmospheric pressure below 100 mm Hg.

10. The method of claim 9 with the step of maintaining the temperature in said chamber as low as 32* F.

11. The method of claim 6 with the step of maintaining the temperature in said cHamber as low as 32* F.

12. The method of conditioning a storage chamber for preserving foods, plants and the like comprising, maintaining a sub-atmospheric pressure in said chamber providing a space adjacent said chamber and separated therefrom. maintaining a supply of water in said space introducing air at atmospheric pressure into said space and contacting said air and water therein, evaporating said water and humidifying said air, conducting said humidified air from said space into said chamber, reducing the pressure of said humidified air that flows into said chamber and expands, cooling the contents of said chamber by the expansion of said air and evaporation of said water, and heating said water.

13. The method of claim 2 wherein said space is enclosed, with the step of 12 said air in said space.