Blast cleaning system

Abstract

This invention relates to a carbon dioxide blast cleaning system for propelling dry-ice pellets by cryogens, namely high pressure nitrogen, helium and/or oxygen, against a surface being cleaned. Carbon dioxide pellets, in a pellet hopper, a blast unit and a blast gun are located at a blast site near the surface being cleaned. A portable cryogenic liquid nitrogen, liquid helium and/or liquid air tank with an ambient air vaporizer is also located at or near the blast site. Cryogenic liquid nitrogen, liquid helium and/or oxygen flow through the ambient air vaporizer to the liquid and is vaporized to form a high pressure gas. The high pressure, cryogenic gas is then brought into the blast unit and mixed with the pellets. The mixture of the high pressure gas and the pellets exit the gun nozzle at high velocities to blast the surface being cleaned.

Dependencies are inferred from the claim text.