Multi-effect brown coal predrying system using superheated steam and process thereof

摘要

A multi-effect brown coal predrying system using superheated steam and a process thereof are provided.  The system has multilevel driers (4) connected in series, each level drier (4) has a feeding device (1-3), a discharge device (5) and at least one level dedusting device (6, 8).  A part of tail gas from the dedusting device (6, 8) is sent back to a corresponding level drier (4) by a pressure equipment (9), whereas the other part of tail gas is sent to a next level drier (4) as a heat source.  A steam heat source is connected with an initial level drier (4).  A part of tail gas from the dedusting device (6, 8) in a final level drier (4) is sent back to the final level drier (4) by a pressure equipment (9), and the other part of tail gas is discharged into the air.