Abstract: A gas venting device for dry ice pelletizers and a method for retrofitting the venting device onto an existing piston and cylinder type dry ice pelletizer. The venting device consists of a venting mesh having wires with a generally trapezoidal cross section. The venting mesh is attached to a forward flange at one end and a rear flange at the opposite end. The two flanges are separated by spacer bars. The spacer bars absorb the compressive force exerted by four rods that extend the entire length of the dry ice pelletizer. Without the spacer bars, venting mesh would buckle under this compressive force. The forward flange is attached to an extrusion cylinder and the rear flange is attached to a home cylinder. The extrusion flange is attached at its other end to a die for dry ice pellet extrusion. The home cylinder is attached at its other end to the rest of the dry ice pelletizer.

Abstract: An improved dry ice pelletizer and method for significantly increased pellet production. The improvement consists of multiple injection ports used for the timed introduction of liquid carbon dioxide into a dry ice extrusion cylinder so that the cylinder can be more completely filled with carbon dioxide snow before extrusion takes place. Part of the improvement stems from the use of a solid mass of carbon dioxide, called a puck, which is chamfered and serves to capture carbon dioxide vapor and snow within the compression cylinder. The resulting improvement in carbon dioxide pellet output is roughly 400% over that achieved by conventional methods. The inventive improvement may also be installed as a retrofit to conventional dry ice pellet extrusion machines.

Abstract: A method and apparatus for a dry ice sublimation system is shown. The dry ice is placed in a vacuum chamber and a vacuum is drawn on the vacuum chamber. As the dry ice sublimates, the cold sublimated gas is fed into a cooling chamber which contains products to be cooled. The temperature of the cooling chamber may be varied inversely with the vacuum in the vacuum chamber, which inversely varies the sublimation temperature of the dry ice and hence the temperature of the sublimated gas. Automatic feed systems may continuously supply product to be cooled or dry ice or both. A bypass around the vacuum chamber allows a turbulence to be created around the dry ice in the vacuum chamber to aid the rate of sublimation.

Abstract: A method and apparatus for effecting the cooling of a stream of air or gas by sublimation of dry ice particles utilizes an upwardly directed, variable velocity stream of air to maintain a supply of dry ice particles provided on a moving perforated conveyor in a fluidized bed condition to maximize the rate of sublimation of the dry ice particles. The cooled air may then be employed to effect the rapid and efficient freezing of a plurality of food articles passing through the same insulated chamber as the dry ice particle conveyor is located, or an adjacent insulated chamber.

Abstract: An apparatus for cutting blocks of ice has a frame which defines a feed chute slightly larger than the uncut block of ice. Four saws are mounted to the frame in pairs. Each pair of saws includes two counter rotating, radial saw blades aligned opposite each other and extending toward one another into the feed chute of the frame. To facilitate the transfer of the uncut block of ice into the feed chute, a feed assembly is attached to the frame. A discharge assembly is secured to the frame to assist in removing the cut ice from the frame. The frame is mounted on a stand in an inclined position with the feed assembly higher than the discharge assembly to allow gravity feed of the ice. A gang of blades may be used with the saws in order to cut the block of ice into smaller sized blocks with one pass through the feed chute. The saw blades have carbide-tipped saw teeth to extend the amount of use between resharpening or replacement.