Method and apparatus for extracting heat from articles with a liquid freezant

Claim 2

The method of claim 2 wherein the liquid halohydrocarbon contacting the article and the vapor is at a temperature at least 5* C. below its normal boiling point and is in the form of a spray which simultaneously contacts the articles and the vapor.

Claim 3

The method of claim 2 wherein the boiling point is -20* to -40* C., the article is food which is being frozen, and the temperatures of the halohydrocarbon contacting the article and the vapor are the same and are at least 5* C. below the normal boiling point of the halohydrocarbon.

Claim 4

The method of claim 4 wherein the halohydrocarbon is dIchlorodifluoromethane.

Claim 5

The method of claim 4 wherein the liquid halohydrocarbon in (A) and (B) is in the form of a spray which simultaneously contacts the food and the vapor.

Claim 6

The method of claim 4 wherein the heat is extracted from the food by an interrupted technique in which the contact between food and liquid is intermittent.

Claim 7

The method of claim 4 wherein food particles are introduced into the heat extraction zone by being pumped into the vessel through a pipe which is not open to the atmosphere, and are removed from the vessel by passing them from the heat extraction zone to an exit opening at a speed not in excess of 100 feet (30.48 meters) per minute.

Claim 8

The method of claim 4 wherein food particles are introduced into the heat extraction zone by first introducing them into the vessel through an entrance opening which is in free vapor communication with the heat extraction zone, and then passing them downward from the entrance opening into the heat extraction zone, and wherein the particles are removed from the vessel by passing them from the heat extraction zone to an exit opening, the speed of the particles being not in excess of 100 feed (30.48 meters) per minute when entering the heat extraction zone from the entrance opening and when being passed from the heat extraction zone to the exit opening.

Claim 9

The method of claim 9 wherein the speed of the particles is less than 50 feet (15.24 meters) per minute.

Claim 10

The method of claim 10 wherein the freezant is dichlorodifluoromethane.

Claim 11

Heat extraction apparatus which comprises A. an open vessel having an entrance opening and an exit opening, B. a heat extraction zone within the vessel for removing heat from articles by means of a liquid halohydrocarbon which is at a temperature below that of the articles and substantially below its normal atmospheric boiling point. C. means for introducing articles into the heat extraction zone from the entrance opening, D. means for conveying the articles through the heat extraction zone, E. means for contacting the articles in the heat extraction zone with liquid halohydrocarbon, thereby generating halohydrocarbon vapor, F. means for contacting vapor formed in the heat extraction zone with liquid halohydrocarbon, thereby condensing substantially all of the vapor contacted, G. means for collecting both the unvaporized liquid halohydrocarbon, which has contacted the articles or the vapor, and the condensed liquid halohydrocarbon, H. means for cooling liquid halohydrocarbon, I. means for recycling the collected liquid halohydrocarbon, and J. means for removing the articles from the heat extraction zone through the exit opening.

Claim 12

The apparatus of claim 12 in which the means for contacting the articles with liquid provides interrupted contact.

Claim 13

The apparatus of claim 12 in which a single means provides the liquid contact with the articles and the vapor.

Claim 14

The apparatus of claim 14 in which the single means provides a spray of liquid.

Claim 15

The apparatus of claim 12 in which the means for introducing articles is a pump communicating with the heat extraction zone through a pipe.

Claim 16

The apparatus of claim 12 in which the entrance opening is in free vapor communication with the heat extraction zone, and the means for introducing articles into the heat extraction zone from the entrance opening is a downward conveyor.

Claim 17

The apparatus of claim 17 which also has an entrance passageway from the entrance opening to the heat extraction zone and an exit passageway from the heat extraction zone to the exit opening.