Two stage material cooler

A two stage cooler for cooling hot material discharged from a furnace comprising:

• A first cooling apparatus for receiving hot material from a furnace including means for moving the material therethrough, means for passing a cooling gas in direct heat exchange contact with the material as it moves through the first cooling apparatus whereby the material is cooled and the cooling gas is heated, and means for conducting at least a portion of the thus heated cooling gas to the furnace;
• a second cooling apparatus including a casing having end walls and sides defining a material shaft, an inlet for receiving material from the first cooling apparatus and an outlet for cooled material;
• said sides each being formed to define a plurality of gas passageways spaced apart along the sides of the material shaft between the inlet and the outlet;
• means for passing cooling gas from one side of the material shaft through the gas passageways therein, through the material in the material shaft for direct heat exchange contact with the material therein for further cooling the materials.
• the material shaft of the second cooling apparatus being dimensioned so that at least some of the cooling gas passes through the other side of the material shaft substantially perpendicular to the flow of material from the inlet to the outlet;
• and
• the means for passing gas through the side is positioned with respect to the inlet for receiving material from the first cooling apparatus so that at least some of the gas flows through said one side and flows through the material to the material inlet, counter current to the flow of material through the material shaft and directly through the first cooler apparatus for supply to the furnace.