Abstract: A hammermill is presented which includes a plurality of hammers each presenting an arcuate striking profile. The hammermill includes a rotor having rods for swingable carrying the hammers thereon and a motor for rotating the rotor. The hammers are longitudinally spaced along the rotor and preferably helically arrayed thereabout. The hammers present a head and a body, the head having an arcuate striking face which may include a point. As the rotor turns, the hammers are free to swing on the rods and comminute material fed into the hammermill. The hammers preferably present symmetrical striking profiles whereby after one profile becomes worn, the position of the hammer on the rod may be reversed to increase the useful life thereof.

Abstract: An upright, cylindrical down draft gasifier has a rotatable grate which supports a quantity of pyrolyzing biomass materials. As the grate is turned, charcoal particles thus formed fall through apertures in the grate and into a collection chamber. Simultaneously a high quality combustible gas is continuously withdrawn. A number of stationary, horizontal rods are disposed above the grate to retard and mix the reactant in the column and force a portion of the charcoal particles through the apertures. Additionally, the rods, in conjunction with the grate, present a shearing action on larger charcoal particles until the latter are crumbled and consequently fall through the grate. As the speed of the rotable grate is increased, the quantity of combustible gas and high quality charcoal is enhanced such that the heating value of the final product is also greatly increased.