at least one stage of a second turbine impeller affixed to the rotating shaft that extends through the second turbine impeller, {HEAD ~ the second turbine impeller} being arranged downstream of {TAIL ~ the first turbine impeller}, 
arranged downstream of
at least one stage of a second turbine impeller affixed to the rotating shaft that extends through the second turbine impeller , { HEAD ~ the second turbine impeller } being arranged downstream of { TAIL ~ the first turbine impeller } ,
OTH OTH OTH 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 HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH