The Flottweg Pond Depth
The pond depth of a Flottweg decanter determines the time that the liquid spends in the decanter (length of the clarifying section and drying section). The pond depth is significant with regard to the length of the clarifying zone or drying zone. The pond depth is set by adjusting the weir plates (when stationary) and/or by adjusting the impeller (during ongoing operation).
Pond depth function when adjusting with a drying zone (shallow pond)
The weir diameter dw is set larger than the diameter of the solids discharge d. The result is a zone in the cone in which the solid is pushed through the dry cone (drying zone). The clarifying zone is reduced by the length of the drying zone.
Pond depth function when adjusting without a drying zone (deep pond)
The weir diameter dw is the same as the diameter of the solids discharge d. This means there is no drying zone, and the clarifying zone is at its maximum size.
Flottweg pond depth
As the pond depth increases (deep pond), the liquid volume and thus the theoretical time spent by the liquid in the decanter increases. This improves the clarifying performance. On the other hand, the drying section in the cone of the decanter bowl is also reduced. As a result, the solid spends less time in the area outside the liquid.
This means the discharged solid is moister and the dewatering performance of the machine is reduced. Depending on the applications or the separation result to be obtained, the Flottweg pond depth is set optimally and thus adapted to the particular requirements and wishes of customers.
Flottweg pond depth and its advantages
- The pond depth makes it possible for solids to be dewatered to a greater extent, which makes for an improved product result
- Improved clarifying performance, for improved total dry solids in the solid
- Possibility for directly influencing the separation performance by changing the pond depth -> optimisation of the separation process
- Optimum adaptation to customers’ requirements in order to achieve the best possible result