A large spiral low-order lignite quality improving
system comprises a
spiral heat exchanger, a
combustion chamber, a lignite feeding device, a
quenching box and a dedusting device. The
spiral heat exchanger is horizontally placed and composed of an outer sleeve, a rotating shaft and a motor, wherein the rotating shaft and the motor are sleeved in the outer sleeve, and the rotating shaft is in transmission connection with the motor. A
spiral blade is axially arranged along the rotating shaft, the wall of the outer sleeve, the rotating shaft and the
spiral blade are all of hollow structures, tow ends of the
spiral blade are communicated with a hollow cavity of the rotating shaft, the inlet end of a hollow cavity of the wall of the outer sleeve and the inlet end of the hollow cavity of the rotating shaft are communicated with the
combustion chamber, and the outlet end of the hollow cavity of the wall of the outer sleeve and the outlet end of the hollow cavity of the rotating shaft are communicated with the dedusting device. The lignite feeding device is arranged on the upper portion of the
spiral heat exchanger and close to the side of the dedusting device, and the
quenching box is arranged on the lower portion of the spiral
heat exchanger and close to the side of the
combustion chamber. The large spiral low-order lignite quality improving
system requires no pre-
drying process, is strong in adaptability of
coal types and particularly suitable for improving quality of sticky lignite, only needs to pre-break raw
coal, is safe in operation, simple in structure and high in heat exchange efficiency, can perform large-scale
continuous production easily and can obtain semi-
coke,
tar and
coal gas with high quality.