METHOD OF DRYING HYDROLYZED LIGNIN AND DEVICE FOR REALIZATION OF THIS METHOD Russian patent published in 2001 - IPC

FIELD: drying lignin-containing materials; processing large amounts of wastes of hydrolyzed lignin in hydrolysis industry. SUBSTANCE: hydrolyzed lignin in subjected to successive heat treatment in revolving drum; at first stage, material is distributed by layers in drying space between two thermal elements made in form of surfaces heated by heat- transfer agent for double-sided drying of material; heating is effected without direct contact of material with heat-transfer agent; heating is continued to temperature not exceeding smoldering point; at second stage, material is subjected to final drying at natural mixing ensured by revolving drum; vapor of moisture and dust0like fraction of hydrolyzed lignin evolved in the course of drying are separated by suction; dried material is discharged through open air- permeable unloading unit. Proposed method may be realized by means of drum-type drier made in form of horizontal drum revolving around longitudinal axis with heating element arranged coaxially inside it; heating element is made in form of flame tube rigidly connected with drum; radial clearance between wall of flame tube and walls of drum forms circular drying chamber where transporting unit is mounted; transporting unit is made in form of guides rigidly spaced relative to each other; flame tube is provided with fuel unit at one end and with blind outlet face at other end; this face divides drum into drying zone in circular drying chamber and cooling and discharging zone; drying zone is provided with unloading unit; cooling and unloading zone is provided with material unloading unit and moisture vapor removal unit; walls of drum are hollow; on side of blind outlet face of flame tube there are branch pipes for removal of used heat-transfer agent which are brought into communication with hollow wall of drum provided with used heat-transfer agent discharge passage. EFFECT: possibility of retaining structure of lignin and its useful properties at enhanced safety of process and high productivity. 9 cl, 3 dwg