| 摘要 |
<p><PICT:0984690/C1/1> Organic fertilizer is obtained by treating moist solid organic waste material in stages with successive groups or species of aerobic micro-organisms, each of which have different requirements for optimum climatic environment by propagating each of the groups or species of aerobic micro-organisms separately in an individually controlled climate conducive to development, transferring the material to be treated in stages into each of said controlled climates in turn without substantially changing the controlled climates and thoroughly inoculating the transfused material at each stage with the propagated group or species of micro-organisms associated with that stage whilst maintaining the controlled climate in that stage during treatment of the material by the micro-organisms, the temperature and CO2 content at each stage, except the last, being maintained at a higher value than in the next succeeding stage. The process is preferably effected in a digester 1 comprising a drum mounted on bearing blocks 2 for rotation about an axis 3 which is slightly inclined with respect to the horizon to allow gravity feed of the materisl through the length of the drum. The digester is divided into a screening chamber 18 at the upper end, four fermentation chambers 11, 12, 13 and 14 and a drying chamber 20. Garbage is introduced through a hopper 22 and tailings such as shoes, stones and metal objects collect near the end wall 26 and may be periodically removed through a port 28. Screened material passes from the compartment 32 to the first compartment of the digester by means of transfer buckets 33 discharge through the bottoms 35 being effected by gravity when the buckets are full. The four stages may be at 170 DEG , 150 DEG , 125 DEG and 105 DEG F. starting from chamber 11, and the requirements of conditioned air may be 5, 10, 15, and 25 cu. ft. per min. per 100 cu. ft. of material in the same order. Up to 50 tons of material may be processed in each chamber in 24-48 hours. Specification 672,913 is referred to.</p> |
