Abstract: An extruder and methods for converting pressurized liquid CO.sub.2 feed into dry ice pellets of predetermined shape and size, wherein the CO.sub.2 snow formation, CO.sub.2 snow compaction, and dry ice pellet extrusion phases occur simultaneously to achieve production rates on the order of 700-1000 lbs/hr. The increased production rates are achieved utilizing sintered plastic filter media to provide enhanced removal of CO.sub.2 gas from the CO.sub.2 snow formation chamber.

Abstract: An extruder for converting pressurized liquid CO.sub.2 feed into dry ice pellets of predetermined shape and size, wherein the CO.sub.2 snow formation, CO.sub.2 snow compaction, and dry ice pellet extrusion phases occur simultaneously to achieve production rates on the order of 700-1000 lbs/hr. The compacted CO.sub.2 snow may be in the form of a solid cartridge or irregularly shaped solids, and such compacted particles may constitute an end product by themselves. The increased production rates are also achieved by enhanced removal of CO.sub.2 gas from the CO.sub.2 snow formation chamber, and use of a bidirectional internal regeneration cylinder to provide compactive force. The extruder is portable, since it only weighs approximately 1000 lbs., can be powered with a non-stationary energy source, and may be used to remanufacture partially sublimated dry ice solids into extruded dry ice pellets of a predetermined shape and size.

Abstract: An amplified mixer-blower device for discharging a feed material at high velocity and enhanced volume using a venturi transport principle. Preferably, carbon dioxide vapor is used as a means for propelling the feed material which may have a different phase of the same composition of the propulsive gas, or constitute an entirely different material. The apparatus is suitable for a number of applications such as neutralizing airborne ammonia vapor or droplets, extinguishing a flammable liquid, and conveying solid materials.