{HEAD ~ The washable filter materials} that may be used in the present invention allows for {TAIL ~ reduced costs} of operation and maintenance 
allows for
{ HEAD ~ The washable filter materials } that may be used in the present invention allows for { TAIL ~ reduced costs } of operation and maintenance
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH