| 摘要 |
<p>In the parent patent an installation for the prodn. of biomethane by digestion of pumpable, organic waste, e.g. liq. manure was described. The installation comprised a number of modular, digestion cells. The number of cells may be varied to suit the capacity of plant required. Provision was made for anaerobic prefermentation. A common pump and pipework system was installed for inter-cell transfer, cell charging and draining. The cells were temp.-controlled in a bain-marie type enclosure and provision was made for pH measurement and control. Methane gas is piped individually from each cell. In this addn. each cell is in the form of an open-topped, vertical cylindrical shell. The cells are gathered closely together on a common base pref. of regular geometrical form, e.g. square or circle. All cells are interconnected by a network of pipes, valves and common pump(s) so that fluid can be transferred any cell to any other cell. All the cells are enclosed within an expandable gas-holder made up of a flexible sheet, e.g. tarpaulin, cover with its lower edge dipping into the bain-marie to form a liq. seal. During the digestive process, the liq. can be advanced progressively from cell to cell, reaching the last cell as fermentation is almost complete. This ensures optimum rate of digestion which is never retarded by crust formation. Anaerobic conditions are enhanced by enclosing the cells in a single gas holder. Gas storage and withdrawal arrangements are simplified.</p> |
