Model‐based Scale Up of Solid Bowl Centrifuges Using Experimentally Determined Material Functions

Abstract

Dedicated to Prof. Dr.-Ing. Joachim Werther on the occasion of his 80th birthdayThe scale up of solid bowl centrifuges is a major challenge as the process and material behavior are complex and difficult to describe. A common approach to forecast the process behavior is to use analytical models and transfer the experience gained from the lab to the industrial scale. In this context, time-consuming and cost-intensive pilot scale experiments are necessary. This paper presents a methodology to improve the scale up process and make it more sustainable by using a numerical model that allows the real-time tracking of the process and a more reliable scale up process. For this approach, the material behavior is derived from laboratory experiments whereby the scalability is given. Here, the determination of material functions allows an accurate representation of the material behavior for solid bowl centrifuges of different scales. The focus of this paper is the detailed explanation of material related functions for the scale up of decanter centrifuges.

Enhancing decanter centrifuge process design with data‐driven material parameters in multi‐compartment modeling

“…Here, the hindered settling velocity depends on the solids volume fraction and the empirical material‐specific parameters , , , which are experimentally determined for each material by an analytical centrifuge LUMiSizer (LUM GmbH). A detailed description of the measurement principle and the methodology is given by Lerche et al [ 38 ] and Zhai et al [ 39 ] While this methodology allows for determining the hindered settling velocity on a smaller scale, it may not accurately depict the settling behavior in a decanter centrifuge. This is discussed further in Section 2.3.…”

“…However, the WBM assumes a characteristic hindered settling factor, resulting in uniform hindrance for all particle sizes. This is discussed in more detail by Zhai et al [ 39 ] Additionally, even though the described methodology for deriving the settling velocity is suitable for more ideal conditions like those found in the analytical centrifuge, its validity may be limited in decanter centrifuges due to the more complex flow conditions present. These limitations are thoroughly discussed in Section 4.1.…”

“…The illustration focuses on relevant material functions. Further details regarding discretization can be found in Gleiß et al [3,32] and Menesklou et al [4] Lerche et al [38] and Zhai et al [39] While this methodology allows for determining the hindered settling velocity on a smaller scale, it may not accurately depict the settling behavior in a decanter centrifuge. This is discussed further in Section 2.3.…”

Resolved Simulation of the Clarification and Dewatering in Decanter Centrifuges

“…The parameters p 1 and p 2 are material specific and derivable from experiments. A detailed description for the experimental determination of the material functions is given by Zhai et al [35]. Kaolin dispersed in water was used to validate the simulation method.…”