Patent ID: 7810990

Claim:
An apparatus for gelling a liquefied gas comprising a churn mixer comprising: a) a cylindrical mixing vessel open at one end, sealed at the other end, and comprising a means of circulating heat exchange fluid in the walls of the vessel, b) a closure lid that fits inside the open end of the mixing vessel, said closure lid comprising o-rings configured to seal the mixing vessel upon compression of said o-rings, an opening, and means for circulating a heat exchange fluid within the closure lid, c) a rod passing through the opening in the closure lid, said rod attached to a perforated plate located inside the mixing vessel and mechanically coupled to a means for moving the perforated plate back and forth between the ends of the mixing vessel, said perforated plate being oriented parallel to the ends of the cylindrical mixing vessel, d) a first valved port in the mixing vessel or closure lid configured to deliver liquefied gas into and optionally configured to remove gelled liquefied gas from the mixing vessel, e) a second valved port in the mixing vessel or closure lid configured to evacuate the mixing vessel and connected to a means for producing a vacuum, and f) a supply of heat exchange fluid in fluid communication with said means of circulating heat exchange fluid in the walls of the vessel and said means for circulating a heat exchange fluid within the closure lid, said supply of chilled heat exchange fluid configured to maintain said heat exchange fluid at a temperature of 0° C. or lower, wherein exterior surfaces of the mixing vessel are covered with a thermally insulating material.