Devices for fermentation of organic refuse and slurries

A silo for producing compost from organic material subjected to aerobic fermentation comprising

• a container having closed sides, an opening in the top through which the organic material is introduced and gas produced by the fermentation process escapes, and an opening in the bottom through which the compost exits, means for supplying gas into the lower portion of the container to traverse upwardly in the container through substantially all of the material being fermented to aid in the fermentation, the interior of the container from the top to a lower portion thereof which is adjacent the bottom being unobstructed so that the organic material will fall of its own weight from the container top to said lower portion as the fermentation process takes place, the gas supplied into the container and gases produced during fermentation moving upwardly through the material being fermented from said lower portion to the opening at the top and exit therefrom while said material is simultaneously moving downward in the opposite direction, and
• means at said lower portion of said container for controlling both the rate at which the material moves downwardly in and exits from the container and the volume of the gas supplied to the material in the container, said controlling means comprising a plurality of elements, means for mounting said elements rotatably about generally parallel horizontal axes, the amount of rotation of said elements determining the spacing therebetween and the rate at which the moves downwardly in and exits from the container.