Principle:
The feed which is sent to the rotary valve door at the upper tube through a feeder and transported to the grading chamber by rotary valve is dispersed and classified fully at grading rotor which are installed horizontally. The coarse particles are thrown to the tube wall and go down along the tube wall. Owing to the action of dual air and firstary air of central tube at fan, the fine powder mixed in the coase is sent to the rotor for classification. At leat, the coarse particles go down along the tube wall and are dischanged from the rotary valve of lower tube, the fine ones are discharged from the exhaust pipe through the gap of the rotor blade. The returing tail gas discharged from wind maching to free air in the collector.

Features:
• The grader is a dry type air grading machine, which is equipped with dual airinlet and horizoutally installed grading rotor and being of a centrifugal type. It is strong in wear-resistance. long in service-life, generally applicable to the classification of free-materials.
• Substances which are even uneasy to be dispersed in the air obtain coarse and fine powder with optimal clean degree.
• It attains a wide grading range. It is selective in a rang of d97=10um. The maximan production capability comes to 8t/h, being widely used in the cement industry.
• It can classify different particles either in ball or slice or fibrous shape and being able to separate materials with different densities.
• High degree of grading particle d75/d25=1.1-1.5.
• High grading efficieney, newton efficiency η=60-90%.
• Compact construction. The size of the grading particle diameter is easy to e adjusted. It is also convenient in assembling, operation, maintenance and cleaning. It also occapies a very small area being small in vibration.
• Powerful production capability, while operating at d97=10um, the capability can reach 1000kg/h approx. It can unitedly operate with other machinery mill to obtain fine powder.