Ore tube drier uses high temperature and high flue gas to dry clean coal in the suspended state, it especially adapts to process fine material with small density, such as the 0 to 13mm wet clean coal whose 0 ~ 0.5mm tablets content does not exceed 40%. Because of the large contact surface of the coal and hot flue gas, the drying speed is fast.
Advantages and disadvantages
Advantages: small footprint, less investment in equipment, large unit volume vaporized water, short residence time of clean coal in the dryer; dryer has simple structure, easy maintenance and low steel consumption.
Disadvantage: low thermal efficiency, large power consumption, large wall wear, high drying cost, higher plant height, complex control procedure, more coal dust.
Structure
rotary dryers include three parts: the drying tube, coal-loosing device and sweeper.
The rotary drying is an upstanding metal tube that is made of rolled steel. It can be divided into several segments and linked or welded by flange. The drying tube diameter is 700 ~ 1000mm and length 15 ~~ 25m. The diameter and length of drying tube depend on production volume and product moisture requirements. The greater of the production capacity is, the larger the drying tube diameter will be; the lower product moisture is, the longer the drying tube will be.
In order to avoid clean coal depositing in the elbow and prevent fire and explosion, spiral sweeper can send the coal deposits on the elbow plot into the precipitator. The spiral sweeper is composed of helical screw shaft, helical blades and transmission device; the transmission device consists of motor, gear reducer, drive pulley and V-belt.
The role of coal-loosing device is to evenly feed wet clean coal into the drying tube.
