| 主权项 |
1. A sludge processing system comprising:
a centrifugal separator which concentrates the sludge, a concentration measure device which measures the moisture content of the concentration sludge exhausted from the centrifugal separator, a furnace which heat-treats the concentrated sludge, and an automatic control device which receives, from the furnace, the information regarding a heat-treatment state of the concentrated sludge and, controls the centrifugal separator based on the received information, wherein the centrifugal separator includes a bowl by which centrifugal force is applied to the sludge so as to separate the sludge into the concentrated sludge and the separated liquid, a screw conveyor to convey the concentrated sludge contained in the bowl to an exhaust port, a drive motor to rotate the bowl, a differential speed generator to cause the screw conveyor to rotate at a differential speed relative to the bowl, wherein the information received from the furnace to the automatic control device include a moisture content change request regarding the concentrated sludge, and wherein, in response to the moisture content change request, the automatic control device controls as follow (a) to (c): (a) the automatic control device sets a variable range of a differential speed between the bowl and the screw conveyor, and performs a variable control of the differential speed so that the measurements concentration moisture of the concentration sludge achieves a moisture content requested by the furnace within the variable range, (b) the automatic control device performs the variable control of the differential speed so that, when the differential speed varies within a certain range being previously set and the measurements concentration moisture of the concentration sludge maintains the moisture content requested by the furnace for a certain period of time being previously set, a control value of the centrifugal force is decreased as well as the measurements concentration moisture of the concentration sludge achieves the moisture content, requested by the furnace in the centrifugal force being set to the new control value, and (c) the automatic control device performs the variable control of the differential speed so that, when the differential speed remains at a minimum value within the variable range and the measurements concentration moisture of the concentration sludge is higher than the moisture content requested by the furnace, the control value of the centrifugal force is increased as well as the measurements concentration moisture of the concentration sludge achieves the moisture content requested by the furnace in the centrifugal force being set to the new control value.
|
