Thereby, according to the invention, the heater section is provided with {HEAD ~ at least one distance control means} arranged for being in contact with the shell surface during the heating and for automatically regulating {TAIL ~ the second distance} by means of a self regulating mechanism 
arranged for automatically regulating
Thereby , according to the invention , the heater section is provided with { HEAD ~ at least one distance control means } arranged for being in contact with the shell surface during the heating and for automatically regulating { TAIL ~ the second distance } by means of a self regulating mechanism
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH