Abstract: This invention relates to an improved apparatus for both processing and removing animal waste products from a pit continually supplied therewith which comprises a ramp-like lid partially covering the pit and cooperating with the contents thereof to seal the latter from the atmosphere except where the waste products enter, a spray at the head of the ramp for flushing the waste materials down and off the lower end thereof into the pit, a heater buried in the material within the pit effective to maintain the temperature thereof at a level conducive to facilitate anaerobic digestion of the bio-degradable portion thereof, means for piping off the bio-gas generated underneath the lid and using a portion thereof to fire the heater, and means for draining the pit remote from the point where the fresh waste enters same, such means being adapted to maintain a near constant level of material within the pit effective to preserve the seal and discharge material therefrom without admitting air thereto.

Abstract: This invention relates to an improved anaerobic digestion apparatus for decomposable organic materials characterized by a digestor covered and sealed by a liquid-filled pond heated with solar energy. The effluent from the fermentation reaction taking place in the digestor has excellent absorptivity for solar energy and is advantageously used as the heat transfer medium filling the pond. The pond is covered with a translucent roof capable of transmitting solar energy, such roof cooperating with the liquid-filled pond therebeneath to produce an artificial environment of reduced sensitivity to atmospheric conditions which is operative to help maintain a condition of stable equilibrium within the digestor. In the preferred embodiment, the vessel forming part of the digestor in which the fermentation reaction takes place comprises an excavated trench lined with a suitable fluid-impermeable membrance while the roof over the pond consists of an inflatable air-supported bubble.