Drum mixer

Mixer apparatus for treatment of bulk materials, particularly foundry sand, comprising:

• a drum mounted for rotation about an axis which extends at least approximately in a horizontal direction, said drum being arranged to define therein an upper drum interior region and a lower drum interior region located, respectively, above and below said axis, said lower drum interior region being arranged to have accumulated therein during rotation of said drum a portion of the bulk material being treated in said mixer apparatus;
• stationary deflection means arranged within said drum in said upper region thereof;
• rotating impact rotor means rotatably mounted within said drum at a location generally below said stationary deflection means to receive bulk material deflected therefrom and to enhance the mixing effect of said apparatus, said rotating impact rotor means including shaft means having a plurality of rigid rotor arms mounted thereon, said rotor arms being arranged to extend radially from said shaft means into said lower drum interior region a distance short of the lowermost point therein to permit in said lower drum region an accumulation of bulk material at a location out of the path of said rotating rotor arms;
• rotation of said drum about said axis operating to propel bulk material located therein upwardly by centrifugal force against said deflection means, said deflection means being structurally configured to deflect and direct said bulk material propelled thereagainst by rotation of said drum away from the inner wall of said drum into a downwardly falling jet directed at said rotating impact rotor means;
• and means unassociated with said impact rotor means and said deflection means for effecting axial conveyance of said bulk material through said drum.