選炭廃水処理に関する研究

粒子の沈降挙動について

抄録

While the Kynch's the ory serves as a usefull means to elucidate the behavior of settling particles, its applicability is limited by the anomalous behavior of practical suspensions such as in colliery waste water, while the same may be said in regard to the application of the Coe-Clevenger formula.
These formulae were derived with the factors limited to the settling curve of mud line with no consideration to the measured concentration gradient in sedimentation zone.
By conventional methods, however, it was very difficult to measure the concentration gradient, hence, the authors attempted to solve this problem by use of γ-ray density meter.
Using this method, measurements could be made continuously without disturbing the settling system.
This report describes the accuracy of density measurement and the results of the change of vertical density distribution against time under several conditions using a few samples such as colliery waste water etc.
Namely, accurate measurements within the value of ±0.002g/cm³ were obtained and the density of suspensions over wide range were determined. The density destribution in a vertical direction in a settling tube was not always continuously changed. The concentration gradient in the presence of added flocculants was discussed.