| 摘要 |
<p>The installation comprises at least 3 modular digestion cells of equal vol. and identical to each other the installation has pumps and a system of pipework so that each cell can be loaded in succession. The number and vol. of cells is pref. related to rate of arrival of raw material so that the last cell is not completely filled until retention time in the first cell exceeds the period required for complete digestion. Pretreatment of material to be charged into a digestion cell is pref. carried out in an anaerobic vessel common to all cells. Pretreatment may include homogenisation as well as adjustment of temp. and pH value. The pretreatment vessel pref. has a vol. equal to that of a digestion cell. Before pretreatment, the raw material is pref. given a period of aerobic fermentation in one or more vessels each of equal vol. to a digester cell. The digested residue is inoffensive and useful as agricultural fertiliser. There is no danger of fresh raw material becoming mixed with digested residue and giving rise to pollution problems. Surface crust problems do not arise since the material is agitated by inter-cell progression.</p> |
