Jump label

Service navigation

Main navigation

You are here:

Main content

Picture of the Month

July 2020 - Methodology for transferring (bio-)chemistry from Batch to Continuous Flow

The coiled flow inverter (CFI) is a promising reactor design providing enhanced heat and mass transfer, narrow residence time distribution, and rapid mixing for a methodology for the transfer of (bio-)chemical reactions in batch mode to two-phase continuous flow. First, this methodology is used for current development of a droplet-based reaction screening system, which was first tested with an automated Paal-Knorr pyrrole synthesis as model reaction. Second, we investigated the bio-catalyzed oxidation of ABTS by the enzyme laccase in a straight capillary for process development in a CFI. An optical evaluation method for determination of reaction rate was used. Comparing Michaelis-Menten kinetic of the batch reaction and the continuous reaction in a capillary, the results show that the batch reaction can be mapped to the capillary setup.

Contact: Julia Grühn, Jens Bobers


June 2020 – Doctoral examination with protective mask

In times of corona, new solutions for exams are needed, including new formats for doctoral examinations. In compliance with the minimum distance and safety regulations, the faculty of BCI decided to permit doctoral examinations in attendance of doctoral candidate and assessors. External assessors as well as faculty members can participate via conferencing services such as Zoom or Webex to ensure the public form of examination.


May 2020 - Vorbereitung von digitaler Lehre im SoSe 20

Aufgrund der Corona-Pandemie stellt die Arbeitsgruppe Apparatedesign die Lehre auf digitale Inhalte um. Für Vorlesungen wie Good Manufacturing Practice (GMP), Sicherheitstechnik und Apparatetechnik oder die englisch-sprachigen Angebote Drops, Bubbles and Films werden die Vorlesungsfolien vertont. Videos mit den Rechenwegen und Lösungen werden für die Übung in Apparatetechnik produziert, die zusammen mit digitalen Sprechstunden auch einen reibungslosen Übungsbetrieb sicherstellen werden.


April 2020 - Whole team of Equipment Design is working at home

Due to the current corona crisis, the AD team is staying at home. The laboratory will remain closed and lectures and exercises will be digitalized. Many of those responsible persons are currently looking for solutions and best practices for implementing digital teaching. Please check the pages of the respective lecture for more information.
Discussions with students will take place via video conference, deadlines for final theses have been extended and submissions will only be made digitally. If you have any questions about courses or organizational matters, please contact the responsible persons by email.



March 2020 - Design of an Automated Reagent-Dispensing System for Reaction Screening and Validation with DNA-tagged Substrates

In cooperation with the medicinal chemistry, an automated system for dispensing reagents for DNA-encoded chemistry based on an open-source 3D printer model was developed. It was validated by applying a complex three-component Povarov reaction from DNA-tagged aldehydes, electron-rich olefins, and anilines to DNA-tagged hexahydropyrroloquinolines. A surface-active polymer was used to mediate the reaction between DNA-tagged aldehydes, the hydrophobic anilines, and the olefin. We tested the reaction with an aniline and olefin, each dissolved as stock in five organic solvents. Head-to-head comparison of manually performed and automatically performed experiments by the robot showed that the ADoS reproduced the manually pipetted reactions faithfully and reached yields above 90 % with a polymer concentration of 500 µM.

Contact: Jens Bobers

Corresponding publication: Bobers, J.; Klika Škopić, M.; Dinter, R.; Sakthithasan, P.; Neukirch, L.; Gramse, C.: Weberskirch, R.; Brunschweiger, A.; Kockmann, N. Design of an Automated Reagent-Dispensing System for Reaction Screening and Validation with DNA-tagged Substrates. ACS Comb. Sci. DOI: 10.1021/acscombsci.9b00207


February 2020 - Design and Hydrodynamic Characterization of a Draft Tube Baffle Tank for Lab‐Scale

For process development on lab‐scale, it is necessary to have equipment that represents the industrial apparatuses as similar as possible to offer short time‐to‐market. Accordingly, a draft tube baffle (DTB) crystallizer was scaled down from typical m3‐scale to 1 L filling volume and manufactured by the glass blowing workshop of TU Dortmund University. The suspension characteristics were determined for fluidized crystals in saturated solution. For further characterization of the DTB tank, the residence time of the liquid and solid phases were experimentally determined for the continuous operation mode. Additionally, the classifying behavior of the particles in the DTB was investigated. A draft tube baffle tank was developed for lab‐scale operation. The hydrodynamic behavior was investigated by analyzing the residence time distribution of the liquid and solid phase as well as the suspension and classification behavior.

Contact: Mira Schmalenberg

Corresponding publication: M. Schmalenberg, A.-K. Nocon, N. Kockmann, Chemie Ingenieur Technik, Design and Hydrodynamic Characterization of a Draft Tube Baffle Tank for Lab‐Scale, 2020, https://doi.org/10.1002/cite.201900078

bdm_02_20_250µm_Segment 1

January 2020 - Exkursion Emsland Stärke

Im Rahmen der Gruppenarbeit haben 9 Studierende inklusive ihrer Betreuer Julia Schuler und Jens Bobers und Prof. Kockmann am 17.01.20 die Emsland Group am Standort Emlichheim besucht. Großen Anklang fand die Endpräsentation der Gruppe mit dem Thema „Proteingewinnung aus der Kartoffelstärkeproduktion“ bei diversen Mitgliedern der Emsland Group aus Forschung & Entwicklung, Produktion und Technika. Die Gruppe besichtigte die Produktionsanlage zur Gewinnung von Kartoffelstärke und hat einen spannenden Einblick in Labore und Technika zur Entwicklung von Lebensmitteln und technischen Produkten basierend auf modifizierter Stärke erhalten.


December 2019 - We wish you a merry christmas!

The eventful year 2019 is reaching the end. We congratulate Dr. Lukas Hohmann on achieving the doctorate with distinction. The Laboratory of Equipment Designs takes the opportunity to say goodbye to Waldemar Krieger, who left the group this summer, and wish him the best for his future. On the other hand, we would like to welcome again our new research associates Daniel Becker, Lutz Kaiser, Piriyanth Sakthithasan, and Aljoscha Frede, who will reinforce the team in the ongoing years. At the end of the year, we would like to thank our supporters, particularly the students who do research together with us and the alumni who always support us with advice.

We wish you a Merry Christmas and a Happy New Year!


November 2019 - AD at conferences

This year we presented and discussed our research and its results at the ECCE in Florence (September 2019) and at the PAAT in Dortmund (November 2019). At the ECCE in Florence “Application of MicroCT for the Visualization of Mulitphase Phenomena in Small Ducts” was presented by Julia Schuler and “Characterization of a Microfluidic Device Manufactured by Reactive Ion Etching” by Jens Bobers. The posters of Julia Grühn on the topic “Selectivity of Gas-Liquid Reactions in Straight and Coiled Capillaries and CFI” and Mira Schmalenberg on the topic “Comparison of Miniaturized Draft Tube Baffle and Coiled Flow Inverter Crystallizer Construction” were also discussed.

At PAAT Daniel Becker gave a talk on “Design of Bionic Structures for Pressure Vessel Elements”. Lukas Bittorf and Mira Schmalenberg held a tandem talk on “Modular Automation and Feasibility Study of Different Component Systems for Stirred Pulsed Extraction Columns” as part of the ENPRO2.0 project, which also shows how the subprojects of ENPRO2.0 exchange ideas with each other. Additionally, Lukas Bittorf could exchange about his poster “Service oriented architecture for an automated laboratory distillation process module” and Julia Grühn about her poster “Untersuchungen von Gas/Flüssig-Reaktionen im Coiled Flow Inverter (CFI) zur Skalierung vom Labor- in den Produktionsmaßstab” with other participants.

Contact: Staff


October 2019 - Coalescence studies with open source components

To demonstrate the potential of rapid prototyping and physical computing in laboratories and process development, it was possible to set up an Arduino based camera system with open-source components. With this set up, phase separation was detected visually and coalescence diagrams could be recorded automatically. Based on these studies, parameters for process development and control can be derived. Embedded in the KEEN initiative for the integration of AI-supported tools in the process industry, it was shown, that physical computing in a research environment is getting more important in the fundamental education of process engineers.

Contact: Lutz Kaiser


September 2019 – Structural optimization with diatom combs

The examination of possible structural optimization is an essential part in the use of lightweight design. A promising approach to structural optimization is the use of bionic structures coupled with evolutionary algorithms. 
As an example of the potential of this optimization strategy, a lightweight design was developed for a blind flange with the aid of diatom combs. Diatoms are a type of algae and occur in nature in many different types and structures. The different shapes of the diatom can be examined with the help of parameterizable CAD drawings and FEM simulations. The geometric parameters are optimized by an evolutionary algorithm that minimizes the weight and occuring stresses in the component. With this method it was possible to reduce the weight of a blind flange by ca. 50% in comparison to an conventional blind flange under same loads. A first demonstrator was 3D printed in PLA.

Contact: Daniel Becker


August 2019 - This years AD chair trip to Hüttenwerke Krupp Mannesmann

On July 19, 2019, the whole laboratory of Equipment Design with students, assistants, technical and administrative staff had a great trip to the steelwork Hüttenwerke Krupp Mannesmann in Duisburg. After a short introduction to the company and a video of „Die Sendung mit der Maus“ there was a guided tour through the whole manufacturing process from iron ore to steel. We would like to thank HKM and the guides who made this possible. The afternoon ended with barbecue and beach volleyball at the Baldeney lake in Essen.

Contact: Norbert Kockmann


July 2019 - Exkursion Boehringer Ingelheim

Am 3. Juli 2019 hat im Rahmen der GMP-Vorlesung eine Gruppe Studierender mit Prof. Norbert Kockmann und MSc. Julia Schuler die Fa. Boehringer Ingelheim besucht. Neben dem Kennenlernen der Gesamtstruktur eines forschenden pharmazeutischen Unternehmens konnten die Studierenden auch Einblicke in den Ingenieursalltag gewinnen. Eine Führung durch das Info-Center sowie eine Busfahrt über das Werksgelände und der Besuch des Tablettier- und Verpackungsbetriebs rundeten die Erfahrungen ab. Hautnah konnte das Phytozentrum und die Pflanzenextraktion erlebt werden. Hr. Dr. Hagels und seine Kollegen leiteten sehr fachkundig die Führungen. Vielen Dank dafür.

Contact: Norbert Kockmann


June 2019 – Engineering meets Art - Ausstellung im Dortmunder U

Zum Anlass des 50jährigen Jubiläums der Fakultät Bio- und Chemieingenieurwesen arbeiteten Studierende der Ingenieurwissenschaften zusammen mit Studierenden der Musik und Fotografie im Rahmen des Engineering meets Art  Projektes interdisziplinär und erschufen Kunstwerke verschiedenster Art. Dabei ist beispielsweise die Arbeit von Alexander Gunkel in Kooperation der Arbeitsgruppe Apparatedesign mit dem Lehrstuhl für Festoffverfahrenstechnik entstanden, die das mittels einer Hochgeschwindigkeitskamera in Millisekunden aufgelöste Platzen einer Flasche zeigt. Die platzende Flasche ist am 12.06.2019 als Film auf den Bildschirmen am Dortmunder U zu sehen. Die dazugehörige Ausstellung im Dortmunder U ist noch bis zum 23.06.2019 geöffnet.

Contact: Jens Bobers

May 2019 – Local mass transfer and flow phenomena in slug flow

The implementation of conventional sensors is a drawback when investigating mass transfer phenomena within microstructured devices, since they disturb the flow and reactor characteristics. Recently, we developed a non-invasive colorimetric method to acquire local mass transfer information in slug flow. By introducing an Arduino based slider setup, which is equipped with a computer-vision system to track the flow, it is possible to capture the entire life time of a single slug and provide valuable data for the development of theoretical models and validation of numerical simulations.
This setup demonstrates how open-source soft- and hardware can enhance analytical tools and contribute to the fundamental understanding of gas-liquid mass transfer phenomena.

Contact: Waldemar Krieger

Corresponding publication: W. Krieger, J. Lamsfuß, W. Zhang, N. Kockmann. Local Mass Transfer Phenomena and Chemical Selectivity of Gas-Liquid Reactions in Capillaries. Chem. Eng. Technol.  2017, vol. 40 (11), p. 2134-2143


April 2019 - Nature as a model for modern technologies 

The application of biological principles of action to technical applications is described by bionics. Typical fields of work include materials science, sensor technology and mechanics. The biological sample is first modeled and then the application case is simulated. An example for the application of bionic principles in structural mechanics is the use of honeycombs in lightweight construction. Instead of solid material, a sandwich structure with honeycombs is used as filling material. This allows savings in terms of weight and material with the same mechanical load capacity. The use of bionic lightweight construction methods is not yet established in apparatus engineering and will therefore be a task for the future.

Contact: Daniel Becker


March 2019 - Equipment design for the skin of a (bio-)chemical process

The apparatus forms the shell of chemical or physical processes and determines the efficiency and safety of a chemical production plant. Well characterized, robust and scalable apparatuses are important for optimal chemical production and fast, reliable process development from laboratory to production. Based on well-known concepts, we develop miniaturized apparatuses that fit into a fume hood, but offer the full functionality of conventional process steps. In reactors with channels smaller than 3 mm, the so-called microreactors, we can carry out chemical reactions with little consumption but high functionality. With Peltier elements, we measure the heat release of exothermic reactions. In helical tube reactors we can adjust a narrow residence time distribution and influence the selectivity of multiphase chemical reactions. In addition to chemical reactions, separation processes are very important for the efficiency of a chemical process. For example, we have developed the smallest stirred extraction column with an internal diameter of 15 mm, which enables a countercurrent of the two phases through targeted pulsation. A distillation column with rotating internals and an internal diameter of 25 mm allows for continuous separation of mixtures with low flow rates. We can even carry out continuous cooling crystallization in the helical tube. The columns can be interconnected with microreactors and other separation equipment to form a modular overall process with integrated sensors.


February 2019 – Excursion to Merck KGaA, Darmstadt

Within the framework of this semesters‘s group project, 9 students, along with members of the group of Equipment Design and  other guests from the faculty, visited Merck KGaA in Darmstadt on January 31th 2019. The students succesfully presented the results of their group project „ Development of a modular multi-purpose plant for the production of liquid crystals“.  Thereafter, all participants gained valuable insights into fields of activities for chemical and bio engineers at Merck. Students and research associates visited laboratories and pilot plants and learned about the interesting history of Merck at „Corporate History“. All 16 participants were  overwhelmed by the variety of impressions.


January 2019 – Automated liquid handling and dosage systems for chemical screening platform

Exploring new chemical spaces for new reactions, catalysts and molecules is limited by error-prone and time-consuming manual work. Automated, microfluidic and drop-based screening platforms enable massive parallelization of chemical reactions and thus rapid screening of a wide variety of compounds. For this purpose, an automated liquid handling system is required to mix different reactants and dose them into a microreactor. A fully automated and customizable system based on an open source 3D printer design is being developed.
Contact: Jens Bobers


December 2018 - Merry Christmas and a Happy New Year

The eventful year 2018 is coming to an end. The Laboratory of Equipment Designs takes the opportunity to say goodbye to Sebastian Soboll and Felix Reichmann, who left the group this autumn, and wish them the best for their future. On the other hand, we would like to welcome again our new research associates Lukas Bittorf, Mira Schmalenberg, Jens Bobers, Julia Schuler and Julia Grühn, who will reinforce the team in the years to come. At the end of the year, we would like to thank our supporters, particularly the students who do research together with us and the alumni who always support us with advice. We wish you a Merry Christmas and a Happy New Year!


November 2018 - Superposition of Taylor and Dean vortices in coiled capillaries

Taylor and Dean flow are two flow patterns that enhance mass transfer and can be observed in capillaries. Recent studies have shown that a combination of these two plow patterns can lead to further increase of mass transfer. By utilizing a colorimetric method based on the consecutive oxidation of leuco-indigo carmine it is possible to visualize the superposition of Taylor and Dean vortices for a gas-liquid system. Depending on the flow conditions different flow regimes were identified that imply different intensities of the respective vortices. For one case a stratified gas distribution is observed, while the other case is characterized by a good radial distribution of dissolved gas within the liquid slug. In between a transition occurs that shows properties of both regimes. Further work will be dedicated to defining these transitions and describing the impact on the selectivity.

Contact: Waldemar Krieger


October 2018 – Investigation of liquid/liquid flows using Micro computed tomography (μ-CT)

For the examination of multiphase interfaces a non-invasive imaging technique is desirable. Micro computed tomography offers the possibility of the 3 dimensional representation of an object up to resolutions in the submicron range, even in opaque media. CT is based on the attenuation of X-Rays which is proportional to the density of the sample material, its atomic number and also the energy of the X-Rays used for the scan. Thus it is possible not only to gain information about the spatial extension of a single phase but much more to distinguish between different materials and thus information about the spatial extension of different multiphase interfaces. The current picture of the month shows a PTFE tube partially filled with silicone oil, water and air scanned with our Bruker Skyscan 1275.

Contact: Julia Schuler

bdm_10_2018_CT LL_flow

September 2018 - Reactive ion etching for microstructured devices

Reactive ion etching provides a dry etching mechanism, which leads to a highly precise and anisotropic etching behavior. A new manufacturing process for polyimide-based microstructured devices with low surface roughness was developed and applied on reactor geometry for liquid-liquid two-phase-flow. The geometry is evolved to create droplets via flow focusing as the dispersed phase is incised by two continuous phase inlet streams. The droplets are created, when the channel is widened from 100 µm to 300 µm. In order to keep the pressure loss for the developed reactor geometry as small as possible, the manufacturing process was optimized with a view to minimizing surface roughness by using Design of Experiments.

Contact: Jens Bobers


August 2018 - Gas-liquid mass transfer enhancement in micronozzles

Micronozzles can be used for the refinement of gas/liquid flow in order to reduce mass transport limitations. The interfacial area is increased due to the micronozzle induced bubble breakub. In this study, the mass transport coefficient was determined for a microchannel containing a micronozzle and a straight reference channel. For this, a colorimetric method based on the oxidation of dihydroresorufin was employed. Pictures were taken with a high speed camera. After image processing, fields of concentrations could be visualized using heat maps and quantified. A clear enhancement of mass transport using the micronozzle could be found.

Contact: Felix Reichmann

Reference channel: Taylor flow, 20 ml/min
Ref 20 mL_min (0,05 s)
Reference channel: Bubbly flow, 35 ml/minRef 35 mL_min (0,05 s)

Micronozzle: Laminar breakup, 80 ml/min
Laminarer Aufbruch 80 mL_min (0,0167 s)

Micronozzle: Turbulent breakup, 120 ml/minTurbulenter Aufbruch 120 mL_min (0,01 s)

July 2018 - Micro–Computed Tomography (µ-CT)

Since June 2018, the Laboratory of Equipment Design has the opportunity of 3D-scanning by X-ray. The SkyScan 1275 from Bruker together with sophisticated analysis software enables clear 3D-images from various objects. A first test image was taken from a play figure, given with a cross sectional view of the polymer bodies. The Grand Smurf is composed of different parts such as the cap, head and body, or legs. Further investigations will include liquid slugs in capillaries or microfluidic chips.
Contact: Julia Schuler

June 2018 - Modular Coiled Flow Inverter Crystallizer (CFIC) 

Production of fine chemicals and pharmaceuticals often includes solid-liquid suspension flow. For continuous cooling a tubular crystallizer was designed based on the coiled flow inverter (CFI) concept, providing a narrow residence time distribution (RTD) of the liquid phase. Counter-current cooling in a tube-in-tube heat exchange concept was designed and allows an adjustment of the temperature profile. Successful operation of up to 50 g∙min-1 in a compact designed prototype with 4 mm inner diameter was scaled down to a modular CFI crystallizer (CFIC) with an inner diameter of 1.6 mm and varying length from 7.8 to 54.6 m. This leads to a significantly lower consumption of chemicals in process development with lower total mass flow rates of 15 – 20 g∙min-1. Due to modular design, mean residence time (3.8 to 6.9 min) and mean cooling rate (0.6 to 1.4 K∙min-1) can be varied at constant mass flow rate. Crystallization growth rate and yield are analyzed with the L-alanine/water test system and seed crystals of 125 – 180 µm. The next step is to characterize the CFIC in detail for different cooling rates, seed amount and seed crystal size. 

 Contact: Mira Schmalenberg

Corresponding publication: M. Schmalenberg, L. Hohmann, N. Kockmann. Miniaturized Tubular Cooling Crystallizer with Solid-Liquid Flow for Process Development. Conference Paper ASME- ICNMM2018, 10-13.06.2018, Dubrovnik Croatia, ICNMM2018-7660


May 2018 - Thin film resistance thermometer on polyimide foil for micro reactors

Besides the common benefits like enhanced mass and heat transfer, micro-structured reactors have drawbacks due to their micro-scaled structures. Measuring temperature is an important issue for micro process engineering. High solution, non-invasive measurement and robustness are requirements, which should be met by the measuring method.
Thin film technology combines the possibility to manufacture micro scaled structures with great flexibility in choosing material and geometry of the structures. Layers of aluminum with a thickness in nanometer scale are deposed on flexible polyimide foil and structured to obtain conductor tracks, which are used as temperature sensors.
The next step is combining a micro-structured reactor and temperature sensors on a single polyimide foil using reactive ion beam etching to create micro channels inside the polyimide foil.

Contact: Jens Bobers


April 2018 - Arduino based slider setup for bubble tracking in Taylor flow

Recently, low-cost hardware platforms such as Arduino have received increasing attention for equipment and process development. In this work, a vision sensor board (Pixy CMUcam5) is utilized to detect and track bubbles in gas-liquid Taylor flow. Information on the bubble position are processed by an Arduino microcontroller in order to motorize a slider setup that carries the Pixy cam and a DSLR camera. This setup allows for dynamic and automatic microfluidic investigations providing extensive insight into gas-liquid mass transfer and hydrodynamics.

Contact: Waldemar Krieger


March 2018 - Lab-scaled continuous operated spinning band column

Distillation as one of the oldest known separation techniques is widely used in chemical industry. Due to the upcoming change in the modern industry to flexible production with versatile modular plants, it is of high interest to develop continuous operating columns for laboratory scale. This is realized with a continuous operated spinning band column with low hold-up and low pressure drop but high separation efficiency as one possible module for modular plants.

For characterization purposes it is of interest to know the distribution of liquid droplets on the rotating spinning band and the mean residence time of liquid, flowing down the column. For first approaches, this can be conducted with dyed water. Hence, a mean residence time can be calculated for different rotation speeds as well as several feed flows and boiling rates.

Contact: Lukas Bittorf


February 2018 - Development of a surface-coated polymer plate reactor

In an effort to improve mechanical stability for an existing microreactor system made from PVDF-foils [1], a surface-coated microreactor was developed. Stability is provided by a PMMA polymer block, which serves as a base plate. Due to its optical transparency, PMMA allows for optical investigations of processes within the reactor. However, PMMA features little chemical resistance. Therefore, the PMMA plate is coated with a PVDF-foil of 100 µm in thickness. The coating and simultaneous structuring of the channel are carried out via ultrasonic hot embosssing and the sealing of the channel is realized by yet another PVDF-foil in an ultrasonic hot welding process step. The newly developed microreactor shows great results in terms of mixing behavior, residence time distribution and mechanical stability [2]. Application in a developed continuous reaction calorimeter employing highly exothermic chemical reactions showed promising results.

Contact: Felix Reichmann

Corresponding publication: [1] Tollkötter et al., Ultrasonic Hot Embossed Polymer Microreactors for Optical Measurement of Chemical Reactions, Chem. Eng. Technol., vol. 38 (7), pp. 1113-1121, 2014. DOI: 10.1002/ceat.201400522
[2] Hoehr, Reichmann et al., Ultrasonic fabrication of polymer plate reactors with a surface coating, in process.


January 2018 - Exkursion zu Sartorius AG und Boehringer Ingelheim

Am 9. und 10. Januar 2018 macht die Arbeitsgruppe Apparatedesign unterstützt durch den Lehrstuhl FSV eine Exkursion zu Sartorius in Göttingen und Boehringer in Ingelheim. Studierende aus den Vorlesungen Pharmaverfahrenstechnik, Good Manufacturing Practice und Mikroverfahrenstechnik bekamen einen sehr guten Einblick in moderne Produktionsmethoden und Tätigkeitsfelder von Bio- und Chemieingenieuren. Ca. 20 Studierende besichtigten Reinräume und chemische Produktionsstätten und waren von der Vielfalt der Eindrücke begeistert.

Contact: Norbert Kockmann


December 2017 - Flooding in DN15 stirred-pulsed extraction column

In extraction columns, breakdown of the counter-current flow resulting from too high flow rates or an excessive energy input is called flooding. In the DN15 extraction column, flooding is visually detected. During normal operation, the stirred cells in the column are filled with many small droplets (yellow dyed organic phase), which are surrounded by the continuous phase. However, when the flooding point is reached, intense coalescence of the droplets at the column wall and column internals occurs. Consequently, the droplets form a second continuous phase, which leads to plugging of the column.

Contact: Sebastian Soboll

Corresponding publication: S. Soboll, I. Hagemann, N. Kockmann. Performance of Laboratory-Scale Stirred-Pulsed Extraction Columns with Different Diameters. Chem. Ing. Tech., 2017, 89, 1611-1618.


November 2017 - Gas-liquid mass transfer and selectivity in coiled capillaries

Gas-liquid mass transfer can be enhanced by employing helically coiled capillaries, which induce Dean vortices and improve radial mixing. A colorimetric method based on the consecutive oxidation of leuco-indigo carmine was utilized to investigate mass transfer and chemical selectivity in straight and coiled capillaries with high temporal and spatial resolution. Significant differences in concentration distributions were observed as a result of different flow characteristics. Coiled capillaries provided higher conversion, but lower selectivity towards the intermediate product compared to straight capillaries.

Contact: Waldemar Krieger

Corresponding publication: W. Krieger, J. Lamsfuß, W. Zhang, N. Kockmann. Local Mass Transfer Phenomena and Chemical Selectivity of Gas-Liquid Reactions in Capillaries. Chem. Eng. Technol.  2017, vol. 40 (11), p. 2134-2143


Sub content


Photo of Prof. Dr.-Ing. Norbert Kockmann

Prof. Dr.-Ing. Norbert Kockmann

Telephone: 0231 755-8077
Fax: 0231 755-8084


Technische Universität Dortmund
Fakultät Bio- und Chemieingenieurwesen
Arbeitsgruppe ApparateDesign
Geschossbau 3

Room 511