Biomass gasifier and charcoal producer

Claim 1

A gasifier for continuous conversion of biomass into charcoal and combustible gas, said gasifier comprising: a hollow generator having an open top for receiving a continuous supply of said biomass and continuous, unimpeded gravitation of the biomass in the generator; a generally horizontal, flat, slotted grate mounted in said generator and occupying substantially the entire cross-section of said hollow generator for rotation about an essentially upright axis and disposed to receive said biomass thereupon, presenting a char-bed of said biomass on the grate when the biomass is subjected to pyrolysis adjacent the grate; a downdraft air supply pipe extending vertically downwardly into and through through the biomass in the generator and provided with tubular tuyeres in the generator disposed to force a continuous supply of combustion-supporting air into and through said char-bed adequate to provide a high exothermic reaction rate and combustion efficiency and production of charcoal on the grate from said biomass; a plurality of stationary members connected to the generator above the grate and extending into the char-bed for retarding rotation thereof and breaking the charcoal into separate lumps against the surfaces of which the air impinges, said members being proximal to the grate for shearing the lumps against the slots of the grate to disintegrate the lumps into charcoal particles, and forcing the particles downwardly through the slots and substantially reducing the residence time of the char-bed in the generator; and means for withdrawing said particles and said gas generated during pyrolysis from the generator beneath the grate.