It is preferable that the height of the core partition is in {HEAD ~ the range} between {TAIL ~ the height} such that the tip of the nozzle of the core burner is hidden by the core partition and the height such that the tip of the core flame is hidden by the core partition 
It is preferable that the height of the core partition is in { HEAD ~ the range } between { TAIL ~ the height } such that the tip of the nozzle of the core burner is hidden by the core partition and the height such that the tip of the core flame is hidden by the core partition
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD 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 OTH