Sleeve lime kiln structural characteristics and process description

The inner cylinder and outer cylinder are arranged concentrically to form a ring-shaped space, and the limestone is calcined in this ring-shaped area. The kiln is divided from top to bottom into preheating zone, countercurrent calcining zone, parallel calcining zone and cooling zone.

a), the upper inner sleeve lower air inlet to the upper exhaust gas outlet of the sleeve kiln is the preheating zone, 70% of the exhaust gas after calcination through the preheating zone to preheat the stone.

b), limestone calcined in the sleeve kiln is a distinctive feature of countercurrent calcination and concurrent calcination at the same time. Sleeve kiln shell distribution of two layers of combustion chamber will be divided into two countercurrent operation of the calcined belt and a parallel operation of the calcined belt. There are two countercurrent calcination belts from the upper combustion chamber to the upper end of the lower inner sleeve and from the upper combustion chamber to the lower combustion chamber, and a parallel flow calcination belt from the lower combustion chamber to the bottom of the lower inner tube.

c), the upper combustion chamber for incomplete combustion combustion air supply is insufficient. Only about 50%. In the role of the exhaust fan, incomplete combustion flue gas into the upper material layer and from the bottom of the excess air from the airflow to meet, so that incomplete combustion products to be completely combusted. This area is the upper calcined zone. In this area, the direction of the airflow and material flow in the opposite direction, countercurrent calcination, limestone in the early stages of decomposition needs to absorb a lot of heat. So generally does not produce overcooking phenomenon.

d), the lower combustion chamber for the complete combustion, the combustion chamber combustion of high temperature flue gas (temperature < 1350 ℃) into two: a calcined belt through the middle, the upper part of the calcined belt flow to the top of the kiln and the incomplete combustion gas from the upper combustion chamber to meet: the other stream in the lower combustion chamber under the action of the injector down to form a concurrent calcined belt. Through the above design, the pressure, airflow and temperature in the kiln are balanced in the ring section and the whole limestone layer, which ensures the uniformity of limestone roasting, improves the quality of the product, and reduces the unit consumption of the product, and the adaptability of the equipment to the raw material is also stronger compared with the traditional lime kiln.