Portable modular air cleaning system

A modular air cleaning apparatus comprising a filter module having a closed plenum box provided with male and female air flow porting means, one of said porting means providing an air inlet to said module and the other of said porting means providing an air outlet from said module, each of said porting means being substantially cylindrical in form and projecting outwardly from a respective wall of said plenum box, each of said porting means being constructed to have a first predetermined diameter section extending from the wall of the plenum box to a location a short distance outward from the plenum box wall and a shoulder means formed to peripherally circumscribe said first predetermined diameter section at a location corresponding to said short outward distance from the plenum box wall, said shoulder means being constructed to engage an end of a flexible hose for preventing withdrawal of said hose from said first predetermined diameter section, said male porting means having a reduced diameter segment formed outwardly of said first predetermined diameter section and formed to be received within a female porting means of another plenum box of another filter module, and annular sealing means within said female porting means to engage said reduced diameter segment and form a substantially air-tight seal thereagainst.