Indirect heat-drying device and method for drying low-grade coal

摘要

A heating tube is disposed in the rotary tube 3 rotatable based on the central axis, and the to-be-dried object W supplied to one end side of the rotary tube 3 is discharged from the other end side while drying, Provided with first and second indirect heating type rotary dryers (1,2) for discharging liquid components evaporated from the object to be dried (W) by the carrier gas supplied in the tradition (3), the first indirect heating type rotary dryer Indirect heating drying in which the object to be dried (W) discharged from the other end side of the rotary tube (3) in (1) is supplied to one end side of the rotary tube (3) of the second indirect heating type rotary dryer (2) and dried As an apparatus, a low-oxygen concentration gas is supplied as a second carrier gas (G2) into the rotary tube 3 of the second indirect heating type rotary dryer 2, while in the first indirect heating rotary dryer 1, the rotary tube 3 In (3), the atmosphere is supplied as the first carrier gas G1.