Quick freezing system
AssigneeIvan Rasovich
InventorIvan Rasovich
Life of this patent
Estimating the term…
Abstract
Apparatus for quick freezing of food products and the like including an insulating tank with a liquid nitrogen bath, an adjacent chamber, a conveyor system for moving product through the bath and the chamber, and an exhaust system for drawing vapor from the tank into and out of the chamber. A process for quick freezing of food products and the like wherein at least the surface of an item is frozen by immersing the item in a liquid nitrogen bath, after which the item is moved through a chamber and further cooled by vapor from the liquid bath drawn into the chamber.
Claims13
In a quick freezing system for food products and the like, the combination of:
- an insulated tank containing a cryogenic liquid bath for quickly freezing items therein and having means defining an enclosed space over said tank with an inlet and an outlet;
- an inlet receptacle at said tank inlet positioned for receiving cryogenic vapor from said tank, said receptacle including means for receiving atmosphereic air for mixing with the cryogenic vapor to form a gas mixture;
- first duct means for withdrawing said gas mixture from said receptacle;
- a temperature sensor for sensing the temperature of said gas mixture and providing a temperature signal;
- an elongate, horizontally disposed insulated chamber having an inlet and an outlet, with said tank outlet positioned at said chamber inlet providing a vapor flow path in the zone between said tank and chamber;
- a first conveyor belt in said tank for moving a product from said tank inlet to said tank outlet into and out of said liquid bath along a generally horizontal path;
- a second conveyor belt in said chamber for moving a product through said chamber from said chamber inlet to said chamber outlet along a generally horizontal path with said tank outlet and chamber inlet disposed for transfer of product through said zone from said first conveyor belt to said second conveyor belt;
- exhaust means coupled to said chamber adjacent said chamber outlet for drawing vapor from said tank through said zone and through said chamber and removing vapor from said chamber,
- said exhaust means including second duct means between said chamber and the atmosphere and control means for controlling the flow through said second duct means as a function of said temperature signal;
- and
- means connecting said temperature signal from said temperature sensor to said control means.
In a process for quick freezing of food products and the like, the steps of:
- freezing at least the surface of an item by immersing the item in a cryogenic liquid bath while moving the item in a first generally horizontal path;
- moving the item from the liquid bath into and out of a chamber along a second generally horizontal path, including transferring the item from the first path to the second path;
- drawing vapor from the liquid bath adjacent the location where the item is initially immersed and mixing air with the vapor to provide an air-vapor mixture;
- sensing the temperature of the air-vapor mixture to provide a temperature signal;
- drawing vapor from the liquid bath into and through the chamber for further cooling of the item as it passes through the chamber;
- and
- varying the rate of flow of vapor through the chamber as a function of the temperature signal.
Dependencies are inferred from the claim text.