摘要 |
<p>The material is spread successively in layers forming a moist mass (M). Each layer is mechanically-mixed (4) immediately after spreading, with the immediately-underlying layer : Layers are formed as strips, mixing (4) being carried out along them. Odd numbers of strips are formed; spreading taking place in one direction on a first, then in the opposite direction on the next, and so on to the end, then back to the first. Mixing forms a swathe. The mass is 0.5-3 m high and several meters wide. It is formed in a glasshouse, with five changes of air per hour. Internal recirculation is 10-50 times per hour. Temperature, moisture and gas content of the air are measured, controlling its replacement rate from the results. The material is sewage sludge. Layers are spread and mixed as described, with a frequency between once an hour and once a week. Between several spreading operations, the mass is turned once. An independent claim is included for the plant carrying out the method.</p> |