Method and apparatus for drying sludge

An apparatus for drying waste materials including a liquid, comprising:

• a plate member having an upper planar surface;
• an endless screen belt comprising a wall, said wall defining a hole extending through said screen, a portion of said belt being in sliding contact with said upper planar surface of said plate member such that said wall and said planar surface combine to define an upwardly disposed cavity to receive waste;
• means for disposing said waste into said cavity;
• means for advancing said screen belt and the hole therein in an endless path along said upper planar surface such that a portion of said waste received in the cavity is dragged across said plate member;
• and
• means for heating said plate member such that said liquid is separated from said waste by evaporation.

A method of removing water from a waste material having a solid waste component and a liquid water component, comprising the steps of:

• disposing said waste material into a layer on a planar surface;
• injecting air into said layer such that said waste material floats to the top of said layer, leaving said liquid water at the bottom of said layer;
• and
• heating said planar surface such that said water is separated from said solid waste component as gaseous steam.

An apparatus for drying waste materials including a liquid, comprising:

• a plate member having an upper planar surface;
• a screen defining at least one hole extending through said screen, said screen being in sliding contact with said upper planar surface of said plate member;
• means for disposing said waste onto said belt such that a portion of said waste passes through said hole and contacts said upper planar surface of said plate;
• means for advancing said screen and said hole in a path along said upper planar surface such that said portion of said waste is dragged across said plate;
• and
• means for heating said plate member such that said liquid is separated from said waste by evaporation.

An apparatus for drying waste materials including a liquid, comprising:

• a plate member having an upper planar surface;
• an endless screen belt defining a plurality of holes extending through said screen, said screen being in sliding contact with said upper planar surface of said plate member;
• a plurality of rollers including a first roller, said rollers supporting said screen;
• means for disposing said waste onto a portion of said belt in contact with said plate such that a portion of said waste passes through said holes and contacts said upper planar surface of said plate;
• means for rotating said rollers such that said screen belt passes along a path along said upper planar surface and such that said portion of said waste is dragged across said plate;
• means for heating said plate member such that said liquid is separated from said waste by evaporation and escapes as vapor;
• a plurality of teeth radially extending from said first roller, said teeth configured to fit within corresponding holes in said screen when said holes pass over said roller, such that teeth push dried waste from within said holes;
• and
• heat exchanger means for capturing said vapor and transferring heat from said steam to said waste prior to disposing said waste onto said belt.

A method of drying waste material having a water content, comprising the steps of:

• dragging a screen in a path across a flat plate;
• disposing said waste material upon said screen such that said waste material is dragged along said plate by said screen;
• and
• heating said plate such that a portion of said water evaporates from said waste material and escapes as steam.

A method for drying a sludge having a solid waste component and a liquid water component, comprising the steps of:

• dragging a screen in a path across a flat plate;
• disposing said sludge into a layer upon said screen such that said sludge is dragged along said plate by said screen;
• injecting air into said sludge layer such that said waste material floats to the top of said layer, leaving said liquid water at the bottom of said layer;
• and
• heating said planar surface such that said water is separated from said solid waste component as gaseous steam.