Rotary Dryer is used to remove moisture from material using hot gases to heat the feed material and to evaporate the water. Rotary Dryers are suitable for drying wide range of materials continuously because of its ability to process material having considerable variation in size and composition. Rotary dryer is mainly for dealing with material in large quantities. As reliable operation, operating flexibility, adaptability and large capacity, this dryer is widely used in metallurgy, building materials, food, light industry, chemical industry, coal, medicine and mining industries. It plays a significant and non-substitutable role in these industries. And to be more specific, it is as follows:
(1) Its technical performance and operation determine the quality, output and cost of the product to a large extent. The folk “As long as the rotary kiln moves, there are thousands and thousands of things” is a vivid description of the importance of rotary kiln in production.
(2) In the application fields of rotary kilns, the number of cement industry is the largest. The entire production process of cement can be summarized as "two grinding and one burning", of which "one burning" is the process to calcine the prepared raw material to clinker under high temperature in rotary kiln. Therefore, rotary kiln is the principal equipment in cement production, and it is commonly known as the "heart" of the cement plant.
(3) In the building material industry, apart from the calcination of cement clinker, rotary kiln is also used for clay and limestone calcination and slag drying; in the production of refractories, using rotary kiln to calcine raw materials can make it dimensionally stable, strength increased , and then process and moulding can be easier.
(4) In ore beneficiation process, rotary kiln roasts lean iron ore in a magnetic way, so that the ore changes from original weak magnetic to strong magnetic in order to facilitate magnetic separation.
(5) In chemical industry, rotary kiln is used to produce soda, calcine phosphatic fertilizer and barium sulfide. In the 1960s, LapPle from United States invented the new technology of using the rotary kiln to produce phosphoric acid, which has the advantages of low energy consumption, less electricity, no sulfuric acid, and with low grade phosphate rock.
(6) In environmental protection, using cement kilns to burn hazardous waste and garbage has had a history of more than 20 years in developed countries, which brings reduction, harmlessness and resourcezation of the waste.
