The present invention relates to a two-stage down-suction
biomass gasifier, the upper part of a gasifier body is connected with a
pyrolysis tube, a feed
auger is arranged in the
pyrolysis tube, the
pyrolysis tube is provided with a pyrolysis gas outlet, one end of the pyrolysis tube is connected with a feed hopper, a side upper surface of a feed port of the pyrolysis tube is provided with a returning ash inlet, the feed hopper is internally provided with a two-stage
cut-off
brake valve, the other end of the pyrolysis tube is communicated with an accumulation ash
carbon layer in the gasifier body by an ash falling
pipe, the ash falling
pipe is internally provided with a two-stage ash falling
pipe cut-off
brake valve and an ash falling pipe air inlet, an ash removal furnace grate, an ash
retainer ring and an ash removal device are arranged under the accumulation ash
carbon layer of the gasifier body, the ash removal device is connected with an ash
discharge auger by an ash collection hopper, and the ash
discharge auger is connected with the returning ash inlet.
Tar efficient removal and
biomass energy efficient conversion can be realized by pyrolysis and
solid product separation and difference
processing methods, and by homogeneous
partial oxidation of pyrolysis components and smoldering
combustion oxidation activation of
solid coke, reactivity of the pyrolysis components and the
solid coke are enhanced, and efficient
tar removal and gasification conversion effects can be ultimately realized.