Patent ID: 6240743
Filing Date: 2001-06-05
Classification: C01B

Abstract:
A method of retrofitting a dry ice pelletizer that forms dry ice pellets from a source of liquid CO.sub.2 having the following steps:disconnecting an extrusion cylinder from a hydraulic cylinder and a die;removing liquid CO.sub.2 lines from injection ports of said extrusion cylinder;replacing said extrusion cylinder with a shorter extrusion cylinder and a circumferential mesh attached to a second end of said shorter extrusion cylinder;reconnecting said hydraulics cylinder and said die to said shorter extrusion cylinder and said circumferential mesh, said die being located at a first end of said shorter extrusion cylinder; andreattaching said liquid CO.sub.2 lines to said injection ports of said shorter extrusion cylinder, said injection ports operated by a controller, said controller moves a piston in a reciprocating manner inside said shorter extrusion cylinder by said hydraulics cylinder, said liquid CO.sub.2 is injected into said shorter extrusion cylinder through said injection port and flashes inside thereof, and when said piston moves to said first end, solid CO.sub.2 formed in said shorter extrusion cylinder as a result of said flashing is forced outward towards said die, when said piston moves to said second end, gaseous CO.sub.2 escapes through said mesh, and the cycle repeats.