products to be contacted with carbon dioxide snow are food products and sensitive chemicals such as catalysts or polymer starting materials because of problems with clogging of snow and water ice in apparatus such as the prior art in fig1 the present invention was conceived and developed to overcome such problems with reference to fig2 and fig3 the purge system of the present invention is viewed in its first embodiment the carbon dioxide snow generator consists of a reversing diffuser chamber 10 into which a j tube snow separator 12 is positioned the j tube snow separator is fed by a liquid carbon dioxide inlet 18 affixed to the end of the j tube which resides outside the diffuser chamber 10 supply of the liquid carbon dioxide from the inlet 18 to the j tube 12 is controlled by a separator solenoid valve 22 when the valve is in the open position high pressure liquid carbon dioxide passes from the inlet 18 into the j tube snow separator 12 and is expanded through an expansion orifice 40 which is not shown in detail in the figures as is recited by the prior art the expansion of liquid carbon dioxide to a pressure below its triple point creates a two phase mixture of solid carbon dioxide and gaseous carbon dioxide this two phase mixture of solid and gaseous carbon dioxide is accelerated through the curved pathway 42 of the separator 12 due to the pressure differential therein as the solid and gaseous carbon dioxide flow through the curved portion of the separator 12 the solid carbon dioxide snow is forced by its greater weight against the radial outer section 46 of the tube while the gaseous carbon dioxide.