Rotary dryers are used for drying various raw materials and fuels with relatively high initial moisture content.
They have sufficiently high production capacity. Also, today it is the only equipment using which you can easily dry various lump materials.
During rotation of the dryer occurs continuous stirring of the material to be dried, which in turn allows you to use drying gas of very high temperature (up to 4500С for highly flammable coal, up to 950°С for various raw materials and additives). Using of gas heated to the temperature higher than the average makes this type of drying apparatus a relatively cost-effective devices, both in terms of cost of electricity required for rotation of the rotary dryer and aspiration, and amount of heat consumed!
The main drying agent in rotary dryers is highly heated air or combustion gases.
The material being treated and drying agent move inside the drum in one direction (cocurrent) or towards each other (countercurrent). Cocurrent is used in those cases when at the beginning of the process higher drying speeds are permitted compared to the end of the process, and the temperature of the dried material shall not rise too high. In it's turn, countercurrent can be used when high drying speed is permissible only at the end of the process and temperature of the dried material at exit can reach high values.
For example, in the cement production industry rotary dryer operating based on cocurrent principle are commonly used.
The construction of the rotary dryer is made from steel sheets of different thicknesses, 9-16 mm; welded structure is most commonly used.
Rotary dryer is mounted on a pair of supports with slight tilt to the horizon, 4-6%. The mechanism is driven by an alternating current electric motor via gearbox and one open crown gear.
Rotary dryers are involved in continuous processes and designed for non-stop operation. Service life of this type of equipment is measured in decades. For more than 70 years Samara plant Strommashina has been producing drying equipment for applications in various segments of industry. Rotary dryer under the brand "Strommashina" are supplied to different regions of the Russian Federation, Europe and CIS countries.