Continuous anaerobic digestor system

DETAILED DESCRIPTION OF THE FIGURES FIG.
1 shows the simplest embodiment 10 of the invention, an improved system for anaerobic digestion of organic material to produce methane gas and useful solid and liquid fertilizing materials from waste biomass.
The embodiment comprises a feeder unit 20 and a digestor unit 22.
The feeder unit or reservoir is a means for continuously receiving and feeding biomass or waste organic material into the system and may comprise a feed tank 24, preferably with a closable top 26 and having a funnel shaped lower portion 28 with tubing coils 30 or equivalent for heating the biomass B with steam or other hot fluid.
If desired, steam may be flowed upwardly through the biomass.
The system is continuously charged as the biomass passes down under gravitational force into the intake end of a first conveyor 32 which preferably is a substantially horizontal screw conveyor.
The first conveyor preferably is a closed tube sealed at the first end at the conventional motor drive 34, sealed at the intake from the tank, and sealed at the second end or exhaust into the digestor unit.
The digestor unit continuously processes organic material through the system and includes a cylindrical tank-comprising means or chamber body 36 and first and second end caps 38, 40.
The digestor unit entrance port or intake 42 from the feeder unit is preferably in the upper portion of the first end of the body.
From that point a second screw conveyor 44 axially mounted in the body and of a length and diameter to fill the body substantially so that the biomass taken in is efficiently and simultaneously moved at a uniform rate throughout the length of the body.
The motor drive 46 is similar to that of the first, and proportionally turns the second screw conveyor at a slow rate.
The screw of the second conveyor may advantageously be rotated by means of a worm gear 48 on the shaft 50 of the screw means outside the first end cap and driven by a worm 52 on the shaft of the motor 46, which may be an electric motor with frame attached to the end cap