{HEAD ~ The method} 6 wherein the step of injecting a flow of cold cryogen vapor includes {TAIL ~ the steps} of injecting at least a first flow of cold cryogen vapor into the first conduit means, and injecting at least a second flow of cold cryogen vapor into the second conduit means 
{ HEAD ~ The method } 6 wherein the step of injecting a flow of cold cryogen vapor includes { TAIL ~ the steps } of injecting at least a first flow of cold cryogen vapor into the first conduit means , and injecting at least a second flow of cold cryogen vapor into the second conduit means
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH