{TAIL ~ The combustion heat} generated during incineration of the waste gas mixed with the air establishes {HEAD ~ strong buoyancy} and produces a swirling air stream 
{ TAIL ~ The combustion heat } generated during incineration of the waste gas mixed with the air establishes { HEAD ~ strong buoyancy } and produces a swirling air stream
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH