METHOD AND APPARATUS FOR COOLING HOT PARTICULATE MATERIAL

A method and apparatus for cooling hot particulate material such as cement clinker discharged from a furnace, such as a rotary kiln. A first heat exchanger of the type wherein cooling gas is passed upwardly through the material to cool the material and this gas is heated by the hot material and supplied to the kiln as preheated combustion air. The first heat exchanger is followed by a clinker breaker and a second heat exchanger which includes an arrangement for spraying the hot material with water. The spray cooler is followed by a third heat exchanger of the type wherein cooling air is passed upwardly through the material in direct contact with the material. The cooling air which flows through the third heat exchanger flows directly through the first heat exchanger. A material seal is provided between the second and third heat exchangers to prevent cooling air from passing through the second heat exchanger. A vent from the second heat exchanger is provided to exhaust steam produced when the water contacts the hot material. A control may be provided so that the amount of water sprayed onto the hot material at the second heat exchanger is responsive to the temperature of the material discharged from the third heat exchanger. As a modification, ambient air may be supplied directly to the hottest material discharged from the kiln for passage through the first heat exchanger.