A cryogenic cleaner for and a method of performing cleaning of a surface that
must
be substantially free of contaminants utilizing a multi-stage, multi-mode filtered
carbon dioxide-containing cleaning medium. Multiple stages and multiple types of
filtration/purification are provided to remove contaminants such as hydrocarbons
from the medium. In accordance with preferred embodiments, a filtering/purification
process is provided that desirably utilizes one or more of: condensation of the
hydrocarbon; particulate filtration; chemical filtration using activated filters;
and catalytic oxidation. In certain embodiments, a resiliently mounted nozzle is
provided for spraying a cryogenic cleaning medium on the surface. The nozzle may
be driven in an oscillatory manner at a predetermined amplitude and frequency so
the nozzle spray is delivered in a manner to provide pulsing of the spray and to
provide as "snow plow" effect on contaminants as the spray delivers the cleaning
medium against the surface. The surface is transported past the nozzle, and the
cleaning occurs in an enclosed controlled environment.