Apparatus and methods for cryogenic treatment of materials

An apparatus for cooling or freezing materials to low- and cryogenic-temperature levels comprising;

• a) an external source of low-temperature or cryogenic liquid coolant;
• b) a closed insulated container;
• c) a plurality of hollow shelves within said container, said hollow shelves forming a plurality of flat-bottomed cooling chambers and forming a closed coolant-containment space around said cooling chambers;
• d) means for introducing said liquid coolant into said container to fill said coolant-containment space around said compartments;
• and
• e) a plurality of insulated entry doors providing access into said compartments for positioning said materials into close proximity with said flat bottoms of said compartments so as to allow gradient bottom-to-top heat absorption from said materials by said coolant through said flat bottoms of said compartments for primary cooling of said materials to low-temperature or cryogenic-temperature levels.

A method for cooling materials to low or cryogenic temperatures comprising the steps of;

• a) placing the material into a tunnel consisting of a flat-bottom plate, sides, and top wherein said top, bottom and sides of said tunnel are contiguous to a heat-insulated coolant-containment space containing a pre-determined level of liquid low-temperature or cryogenic coolant;
• b) cooling said materials by utilizing directional bottom-to-top heat absorption from said materials by heat conduction to said coolant through said bottom plate contiguous to said coolant for primary cooling;
• c) controlling the pressure of said coolant to provide primary directional or gradient bottom-plate temperatures;
• d) controlling the level of said coolant below said bottom plate of said tunnel to provide primary directional or gradient bottom-plate temperatures;
• e) collecting vapors produced from liquid-to-vapor conversion by said coolant's heat-of-vaporization equivalents during primary cooling of said material by heat absorption from said material through said bottom plate to said liquid coolant in a ullage space above the liquid-coolant level in said coolant-containment space;
• and
• f) directing said coolant vapors collected in said vapor-ullage space into said tunnel over said materials to provide additional cooling of said materials or to material cooling areas external to said tunnel.

An apparatus for cooling or freezing materials to low- and cryogenic-temperature levels comprising:

• a) an external source of low-temperature or cryogenic-liquid coolant;
• b) a closed insulated container;
• c) one or more chambers within said container, each said chamber having a flat bottom, sides and a top within said container and at least one opening for entry and exit into said chamber, each said chamber being situated within said container so as to form coolant containment spaces around said chamber;
• d) means for introducing said liquid coolant into said container to fill said coolant containment spaces to predetermined levels around said chambers;
• e) a means of entry through said opening into each said chamber for positioning said materials into close proximity with said flat bottom of said chamber so as to allow gradient bottom-to-top heat absorption from said materials by said coolant through said flat bottom of said chamber for primary cooling of said materials to low-temperature or cryogenic-temperature levels;
• and
• f) a means for directing coolant vapors collected in said coolant containment spaces into each said chamber over said materials to provide additional cooling of said materials or to material cooling areas external to each said chamber.