One end of the tube 44 is in communication with a central portion of the tube 45, and {HEAD ~ the other end} of the tube 44 is formed with {TAIL ~ a gas supply hole} 41 
One end of the tube 44 is in communication with a central portion of the tube 45 , and { HEAD ~ the other end } of the tube 44 is formed with { TAIL ~ a gas supply hole } 41
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH