They are then combined with additional yard trimmings loads and conveyed under magnets to a Banner Jenz AZ50 slow-speed shredder, which achieves particle sizes of less than 75mm. Materials are continuously loaded into the biocell composters with a front-end loader. They each have a 60-cubic meter capacity and are equipped with a stainless steel hermetically sealed door and floor plates. The seal and insulation prevent interference from outside temperature, humidity, etc. The units also are completely computer controlled with a 15-minute interval record and continuous readout.
Air is forced into and circulated through the box from a series of holes within the floor.
It is recycled continually until the carbon dioxide concentration in the reactor reaches four percent by mass, which triggers release of the reactor air and introduction of fresh air. Exhaust from the biofilter exits through a stack. The easiest way we found to detect when to change the biofilter is to monitor the air that flows through. In eight experiments done over about one year in 1996, Lambert Otten and Lindsay Dennison of the University of Guelph concluded that there was very little risk of odor problems from this facility. It was believed that after release from the stack, atmospheric dilution would reduce the risk of nuisance odors.