| 摘要 |
<p>PURPOSE:To economically improve the efficiency of agitating action in a methane fermentation tank, by controlling the intensity of agitation to be charged from the outside of a system in a manner such that the difference between the upper and lower measured concentrations of a fermentative liquid inside the fermentation tank is held in a predetermined range. CONSTITUTION:Signals corresponding to the detected concentrations obtd. by detectors 2, 2' for the concentration of sludge provided in sludge inside a fermentation tank 1 are amplified by an amplifier 3 and inputted to an arithmetic unit 4 in every predetermined time. The difference between the concentrations of sludge at the upper and lower parts of the tank 1 is calculated in the arithmetic unit 4 and compared with the preinputted set point of the difference in the concentration of sludge. On the basis of the resulting deviation, the number of rotation of a driving motor for an agitator pump 7 (or a blower or agitator) is calculated, and the result is sent as a value for setting the number of rotation to a rotation regulator 6. When both of the set point and the measured value are zero, the number of rotation is reduced to a predetermined extent.</p> |
