Magnetic filter apparatus

In a magnetic filter apparatus, including a liquid container having an inlet for admitting liquid contaminated by magnetizable material and an outlet for discharging purified liquid, the combination of:

• a wall of spaced, parallel magnetic filter bars disposed between said inlet and said outlet, and having gaps therebetween for the passage of liquid;
• a first endless conveyor arranged to be movable along a first path, and carrying said wall of magnetic filter bars, the longitudinal axes of said filter bars extending generally perpendicular to said first path;
• first drive means arranged and operable for driving said first endless conveyor along said first path;
• and
• a cleaning device for cleaning said magnetic filter bars, said cleaning device being disposed above the level of said liquid outlet, and said first endless conveyor being arranged to move said magnetic filter bars first through said contaminated liquid and then through said cleaning device, said cleaning device comprising:
• second and third, superimposed endless conveyor means disposed on opposite sides of said wall of magnetic filter bars, and arranged to be movable along second and third paths, respectively;
• at least one scraper blade carried by each of said second and said third endless conveyor means, adapted to be engageable with said magnetic filter bars for removing contaminated material therefrom;
• said second and said third paths extending obliquely across said first path, and forming an angle with respect to the longitudinal axes of said magnetic filter bars carried by said first endless conveyor means;
• and
• second drive means arranged and operable for driving said second and said third endless conveyor means for moving said scraper blades along said magnetic filter bars, while said filter bars are being moved along said first path by said first drive means;
• said first drive means and said second drive means being arranged and synchronized so that the advancing speeds for said scraper blades and for said magnetic filter rods are in the ratio 1:sin .alpha..