| 摘要 |
A manure mixture within an anaerobic digestion tank stratifies to form a liquid effluent layer and a sludge layer. Liquid effluent from the liquid effluent layer is withdrawn from the tank through a height adjustable valve. The height adjustable valve is adapted to automatically adjust the position of its intake end within the liquid effluent layer in response to the level of the sludge layer detected by a sludge meter located within the tank. Liquid effluent withdrawn from the tank is passed through a heat exchange system including at least one heat exchanger. Heat from the heat exchanger is transferred to the liquid effluent to produce heated liquid effluent. The heated liquid effluent is reintroduced back into the digestion tank such that the temperature of the manure mixture within the tank is maintained within a suitable temperature range for anaerobic digestion of the manure mixture. Additionally, the heated liquid effluent is sprayed in an upwards direction so as to effect mixing of the manure mixture within the tank. |
