Chapter 7
Dynamic Simulation of Mechanical Fluid
Separation in Solid Bowl Centrifuges
Marco Gleiss and Hermann Nirschl
Abstract Solid bowl centrifuges are used in a wide range of applications in the
process industry. The aim is to separate the individual phases of a liquid/liquid,
liquid/solid or liquid/liquid/solid system. The design of solid bowl centrifuges is
based on the -theory, which does not describe the separation process with a sufficiently high accuracy. This process results in numbers of experiments with high
time and cost expenditure. In addition, -theory only describes the stationary state
and therefore do not allow the calculation of start-up processes and load changes.
This chapter shows a new real-time capable numerical algorithm, which ensures
a high computational efficiency and is therefore suitable for dynamic simulations
of the process behavior of solid bowl centrifuges. The introduction deals with the
state of the art and the existing problems concerning of the design of solid bowl
centrifuges. Subsequently, material functions representing the separation properties
in solid bowl centrifuges are expounded. The developed material functions are the
basis for the dynamic simulation of the process behavior in solid bowl centrifuges
described below. The residence time and flow conditions of the apparatus significantly influence the process behavior for semi-batch and continuous processes. The
last two sections present the dynamic modeling of continuously operating decanter
and semi-batch tubular centrifuges. Example simulations and comparisons to experiments validate the developed dynamic models and demonstrate the applicability for
dynamic simulations.
Nomenclature
A s
Cross section of the sediment [m]
B sc
Screw pitch [m]
C
G-force [−]
D
Flow number [−]
M. Gleiss (B) · H. Nirschl
Institute of Mechanical Process Engineering and Mechanics, Karlsruhe Institute of Technology
(KIT), Karlsruhe, Strasse am Forum 8, 76131 Karlsruhe, Germany
e-mail: marco.gleiss@kit.edu
© Springer Nature Switzerland AG 2020
S. Heinrich (ed.), Dynamic Flowsheet Simulation of Solids Processes,
https://doi.org/10.1007/978-3-030-45168-4_7
237
Dynamic Simulation of Mechanical Fluid
Separation in Solid Bowl Centrifuges
Marco Gleiss and Hermann Nirschl
Abstract Solid bowl centrifuges are used in a wide range of applications in the
process industry. The aim is to separate the individual phases of a liquid/liquid,
liquid/solid or liquid/liquid/solid system. The design of solid bowl centrifuges is
based on the -theory, which does not describe the separation process with a sufficiently high accuracy. This process results in numbers of experiments with high
time and cost expenditure. In addition, -theory only describes the stationary state
and therefore do not allow the calculation of start-up processes and load changes.
This chapter shows a new real-time capable numerical algorithm, which ensures
a high computational efficiency and is therefore suitable for dynamic simulations
of the process behavior of solid bowl centrifuges. The introduction deals with the
state of the art and the existing problems concerning of the design of solid bowl
centrifuges. Subsequently, material functions representing the separation properties
in solid bowl centrifuges are expounded. The developed material functions are the
basis for the dynamic simulation of the process behavior in solid bowl centrifuges
described below. The residence time and flow conditions of the apparatus significantly influence the process behavior for semi-batch and continuous processes. The
last two sections present the dynamic modeling of continuously operating decanter
and semi-batch tubular centrifuges. Example simulations and comparisons to experiments validate the developed dynamic models and demonstrate the applicability for
dynamic simulations.
Nomenclature
A s
Cross section of the sediment [m]
B sc
Screw pitch [m]
C
G-force [−]
D
Flow number [−]
M. Gleiss (B) · H. Nirschl
Institute of Mechanical Process Engineering and Mechanics, Karlsruhe Institute of Technology
(KIT), Karlsruhe, Strasse am Forum 8, 76131 Karlsruhe, Germany
e-mail: marco.gleiss@kit.edu
© Springer Nature Switzerland AG 2020
S. Heinrich (ed.), Dynamic Flowsheet Simulation of Solids Processes,
https://doi.org/10.1007/978-3-030-45168-4_7
237