Cleaning method and apparatus

摘要

Disclosed is a method and apparatus for the blast cleaning of the surface of an object using solid carbon dioxide pellets as the abrasive projected by a gaseous carbon dioxide propellent. The method and apparatus of this invention subjects a portion of a quantity of liquified carbon dioxide contained within a storage vessel to adiabatic expansion to provide a solid phase carbon dioxide and then compressing or extruding the solid phase carbon dioxide to form a plurality of pellets. Another portion of the liquified carbon dioxide is vaporized to provide a volume of gaseous carbon dioxide at above atmospheric pressure which is then used as a carrier and propellent to project the carbon dioxide pellets against the surface of the object to be cleaned. This invention eliminates the need to use a separate compressed air or nitrogen propellent system for a blast cleaning operation.