The Corporation of Mercer University

Michael A Cryer

William D Danielson, Jr

Robert A Babb

A system and method for cleaning or removing coatings, such as paint, from a surface with a stream of particles. A carbon dioxide (CO.sub.2) pelletizer forms carbon dioxide pellets, which are delivered by a delivery system against a surface to be cleaned. The delivery system includes a hopper for containing the pellets and a high pressure air supply. A feeder introduces the pellets from the hopper into the high pressure air. The combined high pressure air and pellets are directed along a delivery hose to a nozzle, which directs the air and pellets against a surface to be cleaned. Temperature sensors are provided to monitor the temperature of the pressurized air at various points in the delivery system. Signals from the temperature sensor are provided in a feedback control manner to a control valve. The control valve controls the introduction of liquid nitrogen (N.sub.2) into the air stream at a mixing chamber in the delivery system. In accordance with the invention, the temperature sensors and feedback controls permit maintenance of the temperature of the high pressure air below the sublimation temperature of the pellets as the pellets are delivered by the delivery system, thereby prolonging the life of the pellets and reducing sublimation prior to ejection from the nozzle.

Growing community of inventors

Byron, GA, United States of America

Michael A Cryer