Extrusion arrangement for a cryogenic cleaning apparatus

In a cryogenic cleaning apparatus wherein pellets of material which sublime from the solid to the vapor state are projected at a body to be cleaned for abrasively cleaning the body, an improved arrangement for producing the pellets comprising:

• (a) a cylinder for receiving a sublimeable material from which the pellets are to be formed;
• (b) an extrusion die positioned at one end of said cylinder;
• (c) said die having a plurality of pellet extrusion apertures formed therein;
• (d) a piston positioned in said cylinder for forcing the sublimeable material under pressure against said extrusion die and causing said material to be extruded through said apertures in said die;
• (e) a backing plate for mounting and re-enforcing said extrusion die in position at one end of said cylinder;
• (f) said backing plate have a plurality of apertures formed thereupon;
• (g) said backing plate apertures having a relatively greater cross sectional area than said apertures formed in said die;
• (h) each of said backing plate apertures positioned for receiving pellets formed by a plurality of said die apertures and passing said pellets through said backing plate apertures;
• (i) a breaker plate positioned between said die and said backing plates;
• (j) said breaker plate having a plurality of apertures formed therein;
• and,
• (k) said breaker plate apertures communicating with said die and backing plate apertures and oriented relative to said die apertures for breaking pellets which are extruded by said die.