FG Verfahrenstechnik

9 Items

Recent Submissions
Energieeffiziente Gärrestaufbereitung

Gienau, Tobias (2018)

Aufgrund der zunehmenden Überdüngung landwirtschaftlicher Flächen durch Wirtschaftsdünger und Gärreste aus Biogasanlagen wird eine ökonomische und ökologische Vollaufbereitungstechnik zur Separation der Nährstoffe und zur Gewinnung von Prozesswasser aus Gärresten und Güllen benötigt. Das Vollaufbereitungsverfahren zur Düngemittelrückgewinnung durch mehrstufige Fest-/ Flüssigtrennung und Membran...

Modelling of coalescence in turbulent liquid/liquid dispersions considering droplet charge

Kamp, Johannes ; Nachtigall, Stephanie ; Maaß, Sebastian ; Kraume, Matthias (2012)

Drop size distributions in liquid/liquid systems within a turbulent flow, being an integral part of many technical applications, can be simulated solving population balance equations. Experimental investigations in stirred toluene/water systems at constant ionic strength of 0.1 mol/L showed that with pH values higher than 11, coalescence is hindered considerably due to electrostatic effects. Wi...

Influence of drop size and superimposed mass transfer on coalescence in liquid/liquid dispersions - Test cell design for single drop investigations

Kamp, Johannes ; Kraume, Matthias (2014)

The detailed understanding of droplet coalescence is important for the accurate description of liquid/liquid dispersions. A test cell is designed which enables serial examinations of the random coalescence process with high repetition rate, good observability and accuracy of experimental parameters. Within this rectangular test cell a rising droplet collides with a pendant one, while recorded b...

Coalescence efficiency model including electrostatic interactions in liquid/liquid dispersions

Kamp, Johannes ; Kraume, Matthias (2015)

The drop size distribution is an essential process variable in liquid/liquid systems and relevant in many technical applications. It can be described by population balance equations. A coalescence efficiency model was developed to be able to describe the well-known coalescence inhibition due to changing pH value or salt concentration. The model includes the attractive van der Waals and repulsiv...

Automated image analysis for trajectory determination of single drop collisions

Kamp, Johannes ; Hänsch, Ronny ; Kendzierski, Gregor ; Kraume, Matthias ; Hellwich, Olaf (2016)

The fundamental analysis of drop coalescence probability in liquid/liquid systems is necessary to reliably predict drop size distributions in technical applications. For this crucial investigation two colliding oil drops in continuous water phase were recorded with different high speed camera set-ups under varying conditions. In order to analyze the huge amount of recorded image sequences with ...

From single drop coalescence to droplet swarms - Scale-up considering the influence of collision velocity and drop size on coalescence probability

Kamp, Johannes ; Kraume, Matthias (2016)

Coalescence modelling in liquid/liquid dispersions is a challenging task and field of investigations up to now, which becomes apparent when comparing the various existent models with their different and partly even contradictive implementation of influencing factors. In this work, systematic investigations of single drop coalescence were used to compare and validate different coalescence effici...

Drop coalescence in technical liquid/liquid applications

Kamp, Johannes ; Villwock, Jörn ; Kraume, Matthias (2016)

The coalescence phenomenon of drops in liquid/liquid systems is reviewed with particular focus on its technical relevance and application. Due to the complexity of coalescence, a comprehensive survey of the coalescence process and the numerous influencing factors is given. Subsequently, available experimental techniques with different levels of detail are summarized and compared. These techniqu...

Systematic coalescence investigations in liquid/liquid systems

Kamp, Johannes (2017)

Liquid/liquid dispersions, which are mixtures of (nearly) immiscible liquids, are an integral part of many technical processes and everyday consumer products. For example, in technical processes the interfacial area is increased by dispersion to enhance mass and heat transfer; or consumer products like lotions and creams consist of stabilised oil/water dispersions. The process efficiency and re...

Development of a method for reliable power input measurements in conventional and single-use stirred bioreactors at laboratory scale

Kaiser, Stephan Christian ; Werner, Sören ; Jossen, Valentin ; Kraume, Matthias ; Eibl, Dieter (2017)

Power input is an important engineering and scale-up/down criterion in stirred bioreactors. However, reliably measuring power input in laboratory-scale systems is still challenging. Even though torque measurements have proven to be suitable in pilot scale systems, sensor accuracy, resolution, and errors from relatively high levels of friction inside bearings can become limiting factors at small...