{HEAD ~ The apparatus} 1 further comprising an outlet filter immediately before the outlet for purified air to remove a majority of particles in {TAIL ~ the air stream} of the apparatus 
{ HEAD ~ The apparatus } 1 further comprising an outlet filter immediately before the outlet for purified air to remove a majority of particles in { TAIL ~ the air stream } of the apparatus
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH