| 摘要 |
PROBLEM TO BE SOLVED: To provide a volume variable type flocculation mixing tank, the volume of whose agitation chamber is made substantially variable to adjust the residence time of flocculated floc in the flocculation mixing tank according to the property and actual state of a stock solution so that stable and predetermined flocculated floc can be formed, and to provide a control method using the volume variable type flocculation mixing tank.SOLUTION: The volume of the agitation chamber is varied by using an elevating/lowering plate according to fluctuations of the property and actual state of sludge. In the concrete, a bottom plate of the flocculation mixing tank is made movable, in other words, is elevated or lowered freely and the residence time of the stock solution, since the stock solution is fed to the agitation chamber until the flocculated floc is formed, is adjusted so that the flocculated floc perfect for a dehydrator in the succeeding stage can be formed. The fluctuations of the property and actual state of original sludge are detected, a lifting device is controlled according to the solid content of the original sludge, the optimal flocculated floc is formed in the agitation chamber, and dehydrated cake having low water content is formed stably in the dehydrator. |
