Patent ID: 7275395

Claim:
Apparatus for producing dry ice, the apparatus comprising: a self-venting shell assembly that comprises a plurality of separable shell portions having interfaces therebetween, said shell portions being assembled to form a dry ice chamber having an inner surface and at least one vent that is alternately disposable in a non-venting position and a venting position, said vent comprising a seam between two portions of the self-venting shell assembly, said dry ice chamber being constructed such that the vent will shift from its non-venting position to its venting position when a desired amount and/or density of dry ice has formed within the chamber; a delivery system including an inlet line for delivering liquid carbon dioxide from a supply of liquid carbon dioxide to the dry ice chamber; and a release control member which maintains said at least one vent in its non-venting position until pressure within the chamber exceeds a release pressure which indicates that the desired amount and/or density of dry ice has formed within the chamber, whereupon said release control allows said at least one vent to transition to its venting position.