In such an arrangement, the air from the interior of the indoor institution is introduced into {HEAD ~ the cyclone} wherein {TAIL ~ dust} in the air is removed 
wherein
In such an arrangement , the air from the interior of the indoor institution is introduced into { HEAD ~ the cyclone } wherein { TAIL ~ dust } in the air is removed
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH