| 摘要 |
PURPOSE:To keep the concn. of bacteria at the maximum concn. by separating a fermentation vessel into an acid formation vessel utilizing acid forming bacteria and a methane formation vessel utilizing methane forming bacteria, and providing a bacteria recovering mechanism to each formation vessel. CONSTITUTION:When the detected bacteria concn. can not be kept at a set value, a signal for changing the set value for the operation of a bacteria recovering device 18a and a signal for changing the return flow rate of recovered bacteria are sent from a bacteria concn. control circuit 25a to the bacteria recovering device 18a and valves 15a, 17a, and 30a. The set value for the operation of the acid forming bacteria recovering device 18a is calculated by the bacteria concn. control circuit 25a on the basis of output signals from each sensor 14a, 20a, 21a, 22a, and 23a to control the bacteria concn. in an acid forming vessel 1a to the high-concn. set value, and the value is indicated. The corresponding flow rate is simultaneously calculated to control the time sequence of the opening and closing of each valve 15a, 17a, and 30a.
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