Method and apparatus for cooling particulate solids

A method for the cooling of substantially free-flowing particulates in a cooler, said cooler including a housing having a cross section and containing a multiplicity of parallel, horizontally and closely spaced, vertical, expanded heat exchanger plates having smooth exterior surfaces defining flow passages therebetween, said heat exchanger plates being spaced at a distance in the range of about 15 to 100 mm measured from center to center of said plates, said heat exchanger plates each having a thickness in the range of about 5 to 10 mm, each heat exchanger plate having continuous interior flow channels for the flow of cooling fluid therein;

• a fluid inlet and a fluid outlet in communication with said flow channels in each plate;
• a common cooling fluid inlet header connected to the fluid inlets of the multiplicity of plates;
• a common cooling fluid outlet header connected to the fluid outlets of the multiplicity of plates;
• a feed hopper positioned above and attached to said housing and in communication with said flow passages;
• and a discharge hopper positioned below and attached to said housing and in communication with said flow passages, said discharge hopper having flow control means for the controlled discharging of particulates from said discharge hopper;
• comprising the steps of passing a flow of a suitable cooling fluid from said fluid inlet, through said inlet header, through said heat exchanger plates and through said outlet header to said fluid outlet;
• feeding said particulates to said feed hopper and evenly distributing said particulates over the entire cross section of said housing;
• passing said particulates through said flow passages from said feed hopper to said discharge hopper by gravity under flooded, mass flow conditions of the particulates in the cooler;
• collecting said particulates after passing through said flow passages in the discharge hopper for discharge therefrom;
• and controlling the discharge of the particulates at a rate and in an amount relative to the feed of particulates so that said flow passages and the feed hopper are maintained at all times in said flooded state with respect to said particulates, whereby maximum cooling of the particulates is ensured and whereby said particulates pass through said cooler substantially without turbulence, and abrasion and attrition of the particulates are substantially diminished.