Continuous composter having self contained aerating zones

A continuous composter comprising:

• an enclosed elongate tunnel having an upstream end and a downstream end;
• an inlet for garbage in the region of the first end;
• an outlet for compost in the second end;
• the composter comprising:
• at least an upstream composting zone in the region of the upstream end of the tunnel, and a downstream composting zone in the region of the downstream end of the tunnel;
• first means to aerate the upstream composting zone with aerating gases while containing said gases within said upstream composting zone and to recirculate a portion of venting aerating gases within said upstream zone;
• and second means to aerate the downstream composting zone with aerating gases while containing said gases within said downstream composting zone and to recirculate a portion of a venting aerating gases within said downstream zone;
• in which each of said first and second aerating means comprises:
• an air inlet to an upstream end of a header below said conveyor trays in one of the zones;
• means to pass air through said air inlet to said header;
• a gas outlet and an exhaust fan located to draw gases from said header through said one of said zones;
• and
• control means to maintain exhaust suction in said one of said zones stronger than inlet pressure of aerating gases in said one of said zones and in which means are provided to recycle a proportion of gases from said gas outlet to said air inlet.