The Four Drying Zones of Coal Slime Dryer

Jul 21 2014

Coal is a combustible material. Therefore, coal slime must be dried by a professional dryer: coal slime dryer. A coal slime dryer has four zones: material feeding zone, material cleaning zone, lifting plate zone, and material discharging zone. Correspondently, the drying process of coal slime dryer can also include four zones. I will introduce them one by one in the following parts:

The first drying zone

The working principle used in this zone is countercurrent high-temperature air stream drying way. The temperature can reach 43 0 ℃ at the entrance of the coal slime dryer, so wet materials loss lot of water when they come into the dryer. But this temperature does not reach coal slime’s ignition point, so coal slime can not be on fire.

The secondary drying zone

The secondary zone of coal slime dryer uses countercurrent air stream drying method too. But the temperature of this zone is 300 ℃. This zone is also called as highly efficient dewatering zone. Since the rotary drum continuously rotates, so the surface of material in it can not be scorched.

The third drying zone

The third zone of coal slime dryer is called the normal drying zone. The temperature of it is 120 ℃ -210 ℃. There are lifting plates and crushing device in this zone. Materials in this zone are crushed and thrown and then fall down. At the same time, they are preheated and ready to enter into the next drying part.

The fourth drying zone

The fourth zone of coal slime dryer is called high discharging zone. It depends on the negative pressure high-temperature hot air stream produced by fan to remove moisture. Its temperature can reach 60 ℃ -80 ℃. After the above processing, coal slime’s calorific value increases, and its moisture reduces within 8%. Drying process really make the coal slime energy saving.