Patent ID: 6695679
Filing Date: 2004-02-24
Classification: B24C

Abstract:
A system for producing a blasting stream consisting of dry ice particles, entrained in a stream of gas under pressure, said system comprising:a first regulator receptive of a stream of carrier gas under pressure, adapted to maintain an output gas stream at a selected flow rate at a desired pressure; a second regulator receptive of a sequence of dry ice particles, adapted to maintain said sequence at a regulated mass rate; said second regulator being slaved to said first regulator to provide particles at such a rate as to fulfill the dry ice requirement for a selected gas/dry ice ratio; a mixer combining the air and dry ice particles from said regulators to create a blasting stream with the selected ratio; a hose receiving the blasting stream from said mixer; a nozzle attached to said hose, said nozzle having an orifice with an open cross-section from which the blasting stream is discharged; logic and control circuitry responsive to command for an operating pressure and resulting gas flow rate establishing a preferred range of values for the ratio of gas/dry ice, and actuating instructions to provide dry ice at a rate to mix with the stream of air and constitute a blasting stream with a gas/dry ice ratio within said preferred range.