What are the lining structures of lime rotary kilns and what are the requirements for refractories?
The rotary kiln lining structure of rotary kiln and requirements on refractories calcining active lime according to the general output is divided into Nissan 300t, 400 t, 600 t, 800 t, 1000 t, 12000 t of kiln type, calcining zone temperature at 1350 degrees celsius. The kiln is divided into a discharge end, a cooling zone, a burning zone, a preheating zone and a feeding end, and the temperature of each section of the kiln ranges from 1000 DEG C to 1350 DEG C, and the requirements for refractory materials are different. The kiln refractory materials not only to withstand the high temperature impact, but also need to bear the material erosion, kiln rotation stress produced, so not only on the physico-chemical properties of refractory materials have strict requirements, but also for the construction of brick should be strictly.
The physical and chemical properties of refractory materials used in rotary kiln are as follows: physical and chemical properties of refractory materials used in rotary kilnMaterial name: high temperature compressive strength (MPa), softening temperature (DEG C), thermal shock resistance (1100 DEG C, cold water), sub volume density (g/cm3)Magnesia spinel brick is greater than or equal to 50 is greater than or equal to 1700 = 12 = 2.95High alumina brick is greater than or equal to 75 = 1520 = 8 = 2.57High aluminum bricks more than 50 = 1700 = 12 = 1The clay brick is greater than or equal to 30 = 1400 = 12 = 2.30
The current configuration of domestic calcining active lime rotary kiln refractories are as follows: the discharge end of low cement high alumina castable with 3% steel fiber; the cooling zone and the firing zone: dry magnesia spinel brick with high aluminum brick with high temperature; preheating: high alumina brick; low temperature preheating zone: clay brick light clay brick; feeding end: low cement high alumina castable with 3% steel fiber; in addition, brick size also have the corresponding requirements; dimensional tolerances: dimensional tolerances used in different parts of the requirements are not the same, the general control in 2mm; corner damage: general permit edge damage 40mm and 5mm deep within angle loss in the hot and cold surface is allowed to have only one, three edges and the length of not more than 50mm; there are cracks parallel to the use of surface crack is not allowed, cracks of brick surface are allowed.
