@misc{MedinaMendezSchmidtRiebel, author = {Medina M{\´e}ndez, Juan Ali and Schmidt, Heiko and Riebel, Ulrich}, title = {Towards a One-Dimensional Turbulence Approach for Electrohydrodynamic Flows}, series = {11th International Symposium on Turbulence and Shear Flow Phenomena (TSFP11), Southampton, UK, July 30 to August 2, 2019}, journal = {11th International Symposium on Turbulence and Shear Flow Phenomena (TSFP11), Southampton, UK, July 30 to August 2, 2019}, pages = {6}, abstract = {The One-Dimensional Turbulence model is modified in this work for its application to a classical electrohydrodynamic (EHD) problem. Being the first study case, this work is focused on the influence of electrostatic fields and space charge on the velocity field inside a wire-plate Electrostatic Precipitator (ESP) with one-way-coupling dynamics. The study case is an attempt to replicate velocity profiles and Turbulent Kinetic Energy (TKE) budgets obtained in the Direct Numerical Simulation (DNS) carried out by Soldati and Banerjee (1998). Qualitative trends are confirmed in preliminary ODT results, thus showing the potential of the stochastic ODT modeling approach for other types of EHD flows.}, language = {en} } @misc{MedinaMendezSchmidtRiebel, author = {Medina M{\´e}ndez, Juan Ali and Schmidt, Heiko and Riebel, Ulrich}, title = {Towards a One-Dimensional Turbulence Approach for Electrohydrodynamic Flows}, language = {en} } @misc{MedinaMendezSchmidtRiebel, author = {Medina M{\´e}ndez, Juan Ali and Schmidt, Heiko and Riebel, Ulrich}, title = {Extension of the One-Dimensional Turbulence model towards electrohydrodynamic variable density flows}, series = {17th European Turbulence Conference (ETC2019), 3-6 September 2019, Torino,}, journal = {17th European Turbulence Conference (ETC2019), 3-6 September 2019, Torino,}, address = {Turin}, pages = {1}, language = {en} } @misc{LebedynskyyRiebelvanderZwaagetal., author = {Lebedynskyy, Volodymyr and Riebel, Ulrich and van der Zwaag, Till and Haep, Stefan and Kohnen, Boris}, title = {Energetische Optimierung von Elektroabscheidern. Industriebeispiel HKM Duisburg}, series = {Jahrestreffen der ProcessNet-Fachgruppen Mechanische Fl{\"u}ssigkeitsabtrennung und Gasreinigung, 14.-15. M{\"a}rz 2019, Bamberg}, journal = {Jahrestreffen der ProcessNet-Fachgruppen Mechanische Fl{\"u}ssigkeitsabtrennung und Gasreinigung, 14.-15. M{\"a}rz 2019, Bamberg}, pages = {1}, abstract = {Elektroabscheider bew{\"a}hren sich in Rauchgasreinigung als sehr robust und zuverl{\"a}ssig. Allerdings werden zahlreiche und nicht immer genau bekannte Parameter f{\"u}r eine sichere Auslegung von Elektroabscheidern ben{\"o}tigt. Eine nachtr{\"a}gliche Ver{\"a}nderung der Betriebsparameter kann zur Minderung der Zuverl{\"a}ssigkeit eines Elektroabscheiders f{\"u}hren. Das Rauchgas aus dem Stahlkonverter (HKM, Duisburg) wird in einem Nass-elektroabscheider von Partikeln befreit. Als HV-Elektroden kommen sog. „high emission electrodes" zum Einsatz. Diese weisen eine sehr geringe Corona-Einsatz-spannung auf und ersch{\"o}pfen die Leistungsreserven des HV-Trafos bereits bei mittleren Spannungen. Eine weitere Erh{\"o}hung der Spannung ist aufgrund der Strombegrenzung nicht m{\"o}glich. Eine zweistufige auf das Aerosol abgestimmte HV-Elektrode wird entwickelt und im Technikums-Maßstab ausprobiert. Diese erm{\"o}glicht eine {\"a}ußerst effiziente Nutzung des Corona-Stromes. Die Aufladung von Partikeln erfolgt damit fast ausschließlich im gequenchten Bereich, in dem die Gasionen ihre Ladung fast vollst{\"a}ndig auf die Aerosolpartikeln {\"u}bertragen. Eine deutlich h{\"o}here Betriebsspannung kann erreicht werden. Eine originale HKM Elektrode wird einer optimierten im Technikumsversuch gegen{\"u}bergestellt. Der Betriebspunkt (Spannung und Strom) des HKM Elektro-abscheiders wird durch die Ver{\"a}nderung der Aerosol-Anzahlkonzentration und Gr{\"o}ßenverteilung nachgebildet. Abscheideleistungen bei einer typischen Betriebs-spannung sowie bei der maximalen Trafo-Leistung von 205 W pro Abscheiderohr werden erfasst. Die Versuche werden durch eigene Simulationsrechnungen unterst{\"u}tzt. Die Simulationsergebnisse stimmen mit den Messergebnissen sehr gut {\"u}berein. Die optimierte Elektrode bringt folgende Vorteile gegen{\"u}ber der originalen Elektrode: a) 2/3 der Energie werden bei einer gleichen Abscheidung eingespart. b) 9-fache Verbesserung der Abscheidung bei einem gleichen Energieeintrag. Eine technische Umsetzung der gewonnenen Kenntnisse steht in Aussicht.}, language = {de} } @misc{BuergerRiebel, author = {B{\"u}rger, Patrick and Riebel, Ulrich}, title = {Characterization of flame-generated SiO2 aerosols and their utilization in research of high temperature electrostatic precipitation: A project outlook}, series = {Jahrestreffen der ProcessNet-Fachgruppe Gasreinigung und des TAK Aerosoltechnik}, journal = {Jahrestreffen der ProcessNet-Fachgruppe Gasreinigung und des TAK Aerosoltechnik}, doi = {10.13140/RG.2.2.30701.95209}, pages = {1}, abstract = {Gas-phase particle separation at significantly elevated temperatures is a scope since heat recovery units might be operated with higher efficiency and lower maintenance costs when fouling by particulate deposits could be reduced. However, this proves difficult for most separation techniques for numerous reasons (particle size limitations, material limitations, pressure difference limitations). While the upper temperature limit for standard electrostatic precipitators (ESP) operated at ambient pressure and with negative polarity is around 400°C, positive polarity theoretically should allow an operation with temperatures well above 600°C. However, there seems to be very little experience with high temperature ESPs even on the lab scale or small pilot scale. To close this apparent gap in electrostatic precipitation research our current project aims to investigate the characteristics of a SiO2 aerosol and the capabilities of an ESP dealing with said SiO2 aerosol at 600°C and above. The aerosol is produced by combustion of silicone oil (HMDSO) in a propane flame which leads to particle size distributions ranging from below 10 nm up to 400 nm. The median value of the distribution and the total number concentration is a function of the gaseous HMDSO amount introduced into the flame. Increasing the HMDSO supply shifts the median to larger particle diameters but also reduces the total number concentration, which is an interesting phenomenon to be looked into in more detail during the project since coagulation cannot explain this on its own. The observed high number concentrations at low HMDSO feed rates may involve thermal rebound which needs further investigation. Additionally, the bipolar charge distribution typical for flame-generated aerosols has to be considered when deriving an explanation for the observations. The next steps will be a more detailed characterization of the produced SiO2 aerosol and the operation of a high temperature ESP in wire-tube geometry.}, language = {en} } @misc{BuergerRiebel, author = {B{\"u}rger, Patrick and Riebel, Ulrich}, title = {Behaviour of a flame-generated SiO2 aerosol in electrostatic precipitators at elevated temperatures: A back-corona investigation}, series = {Jahrestreffen der ProcessNet-Fachgruppen Mechanische Fl{\"u}ssigkeitsabtrennung und Gasreinigung}, journal = {Jahrestreffen der ProcessNet-Fachgruppen Mechanische Fl{\"u}ssigkeitsabtrennung und Gasreinigung}, doi = {10.13140/RG.2.2.34057.39528}, pages = {1}, abstract = {The removal of high-resistivity dusts from gas flows using electrostatic precipitators (ESPs) is challenging and requires counter-measures to suppress back-corona and subsequent particle re-entrainment. The critical dust layer thickness for the occurrence of back-corona may vary by several orders of magnitude depending on the specific dust resistivity, dust layer porosity, particle size, humidity and operating temperature. Despite the difficulties at elevated operating temperatures, processes involving highly resistive dusts (e.g. oxidic materials) may benefit significantly from utilizing high temperature ESPs (HT-ESPs). This is because the specific resistivity of materials like SiO2, Al2O3 and other oxides decreases below the critical value of 10^11 Ω*cm at higher temperatures. Currently, the separation of oxidic nanoparticle products relies on cloth filters which require exhaust gas quenching prior to dust removal. Using heat exchangers instead to recover excess heat is not feasible due to severe scale formation. Therefore, the development of a reliable HT-ESP would allow heat exchange at clean gas conditions reducing operating costs of the overall process. During preliminary experiments for our ongoing investigation of HT-ESPs, the behaviour of a flame-generated SiO2 aerosol was studied at 200°C in a wire-tube configuration. In order to reach a better understanding of the back-corona, measurements of the particle size distribution, particle charge distribution and electric current were conducted for both polarities. Strong effects are found even though the dust layer thickness is a few μm only. While the separation efficiency decreases rapidly after a critical dust layer thickness is reached, the current uptake increases significantly (up to a factor of 20), and a large number of inversely charged particles is found in the clean gas. These effects may indicate a large-scale back-corona. A detailed discussion will be given on the basis of aerosol size and mobility distributions, SEM images and resistivity measurements of the dust layer. We gratefully acknowledge the financial support for this project (EFRE-StaF 23035000) by the European Fund for Regional Development.}, language = {en} } @misc{BuergerRiebel, author = {B{\"u}rger, Patrick and Riebel, Ulrich}, title = {Electrostatic Charging and Precipitation of Nanoparticles in Technical Nitrogen: Highly Efficient Diffusion Charging by Hot Free Electrons}, series = {Jahrestreffen der ProcessNet-Fachgruppen Computational Fluid Dynamics und Gasreinigung}, journal = {Jahrestreffen der ProcessNet-Fachgruppen Computational Fluid Dynamics und Gasreinigung}, doi = {10.13140/RG.2.2.35735.11687}, pages = {1}, abstract = {Electrostatic charging and deposition of a liquid nano-aerosol was studied in dry air and in technical (3.6 \% O2) nitrogen. The experiments have shown that electronic charging of aerosols can be important in technical scale electrostatic precipitators (ESPs). Already at operation voltages just slightly above the corona onset voltage, the contribution of the free electrons to the overall current is estimated to be around 50 \%. Due to the high temperature of free electrons, diffusion charging by free electrons allows to reach exceptionally high particle charge and extremely high precipitation efficiency. A strongly simplified theoretical model was developed, which gives a good prediction of particle charge based on averaged values of particle diameter, current density, electric field strength, electron temperature and residence time. The ion mobilities were determined by fitting the current-voltage characteristics with a modified Townsend (Monrolin et al. 2018) equation and are significantly higher than the values typically used to describe diffusion charging in air. This may be ascribed to the very dry gas phase and the short average lifespan of the ions under ESP conditions, which is in the order of 1 ms. From the practical point of view, electronic charging might be relevant in a number of technical applications, including high temperature ESPs, ESP applications in dry and oxygen-free gases and pulsed corona systems. We gratefully acknowledge the financial support for this project (EFRE-StaF 23035000) by the European Fund for Regional Development. Monrolin, N., Praud, O., Plourabou{\´e}, F. 2018. Revisiting the positive DC corona discharge theory: Beyond Peek's and Townsend's law. Phys. Plasmas 25, 063503; doi: 10.1063/1.5031780.}, language = {en} } @misc{BuergerRiebel, author = {B{\"u}rger, Patrick and Riebel, Ulrich}, title = {Electrostatic charging and precipitation of nanoparticles in technical nitrogen: Highly efficient diffusion charging by hot free electrons}, series = {Journal of Aerosol Science}, journal = {Journal of Aerosol Science}, number = {141}, issn = {1879-1964}, doi = {10.1016/j.jaerosci.2019.105495}, pages = {17}, abstract = {Electrostatic charging and deposition of a liquid nano-aerosol was studied in dry air and in technical (3.6 \% O2) nitrogen. The experiments have shown that electronic charging of aerosols can be important in technical scale electrostatic precipitators (ESPs). Already at operation voltages just slightly above the corona onset voltage, the contribution of the free electrons to the overall current is estimated to be around 50 \%. Due to the high temperature of free electrons, diffusion charging by free electrons allows to reach exceptionally high particle charge and extremely high precipitation efficiency. A strongly simplified theoretical model was developed, which gives a good prediction of particle charge based on averaged values of particle diameter, current density, electric field strength, electron temperature and residence time. The ion mobilities were determined by fitting the current-voltage characteristics with a modified Townsend (Monrolin et al. 2018) equation and are significantly higher than the values typically used to describe diffusion charging in air. This may be ascribed to the very dry gas phase and the short average lifespan of the ions under ESP conditions, which is in the order of 1 ms. From the practical point of view, electronic charging might be relevant in a number of technical applications, including high temperature ESPs, ESP applications in dry and oxygen-free gases and pulsed corona systems.}, language = {en} } @misc{BacherRiebel, author = {Bacher, Christian and Riebel, Ulrich}, title = {Investigation of electrohydrodynamically enhanced turbulence in wire-tube electrostatic precipitators for enhanced mass and heat transfer}, series = {ICESP 2018, Charlotte, USA, 9-11 October 2018}, journal = {ICESP 2018, Charlotte, USA, 9-11 October 2018}, pages = {6}, abstract = {Enhanced heat and mass transfer due to electrohydrodynamically induced flow in electrostatic precipitators provides a potential opportunity for versatile new applications in the process industry. After a short review of the physical fundamentals it is explained why measurements of the pressure gradient play an important role in the design principles for this technology. Its external influence by operating parameters like voltage polarity and aerosol conditions will also be shown. In the second part, the feasibility of enhanced mass and heat transfer is demonstrated based on laboratory measurements. In combination with the previously discussed pressure gradient measurements, methods for simplified engineering concepts like equivalent mean flow velocities or turbulent diffusion coefficients are shown. The topic is rounded off by outlining a potential use in decentralized power generation.}, language = {en} } @misc{BacherRiebelLebedynskyyetal., author = {Bacher, Christian and Riebel, Ulrich and Lebedynskyy, Volodymyr and Fischer, Silvio}, title = {Discharge electrode geometries and energy efficiency in one-stage electrostatic precipitators at high aerosol concentration}, series = {ICESP 2018, Charlotte, USA, 9-11 October 2018}, journal = {ICESP 2018, Charlotte, USA, 9-11 October 2018}, pages = {7}, abstract = {In order to help answering the question "Which electrode design is the best?", the precipitation performance of a tubular ESP was determined for different electrode designs with special attention to specific energy consumption. Experiments were conducted in a wire-tube arrangement with a high loading of liquid submicron particles. The experiments are supplemented by numerical simulation results showing the effect of residence time and power consumption on separation efficiency. By combining the own experimental results with seemingly contradicting statements of the literature, the authors provide also some general guidelines for discharge electrode design when designing or upgrading electrostatic precipitator plants.}, language = {en} } @misc{BacherRiebelMedinaMendezetal., author = {Bacher, Christian and Riebel, Ulrich and Medina M{\´e}ndez, Juan Ali and Schmidt, Heiko}, title = {Nutzbarmachung des elektrischen Windes zum verbesserten W{\"a}rme und Stofftransport im Elektroabscheider}, series = {ProcessNet 2020, Fachgruppe Gasreinigung}, journal = {ProcessNet 2020, Fachgruppe Gasreinigung}, pages = {1}, abstract = {Zur F{\"o}rderung einer nachhaltigeren Wertsch{\"o}pfungskette werden im Rahmen der Energiewende st{\"a}ndig neue Verfahren und Konzepte zu deren Umsetzung entwickelt. Eines dieser Konzepte befasst sich mit der Zusammenf{\"u}hrung bislang entkoppelter Prozessschritte in Gasreinigungssystemen aus der Energie- und Anlagentechnik. Aus den daraus resultierenden Einsparungen bei den Investitionskosten profitieren nicht nur die klassischen Energieerzeugeuer und Produktionsanlagen in der chemischen Industrie, sondern es werden auch neue Anreize zur dezentralen Energieeinspeisung von kleineren und mittelst{\"a}ndischen Unternehmen gesetzt. Elementarer Bestandteil dieser Gasreinigungssysteme sind h{\"a}ufig Elektroabscheider, welche weit verbreitet im Einsatz sind um Abgase von St{\"a}uben bzw. Aerosolen zu befreien, oder um staubf{\"o}rmige Wertprodukte aus Gasstr{\"o}mungen abzuscheiden. Die in Elektroabscheidern prinzipbedingt vorhandenen elektro¬¬hydro¬dyna¬mischen Str{\"o}mungen, auch als elektrischer Wind bezeichnet, sollen nun systematisch genutzt werden, um neben der Aerosolabscheidung gleichzeitig Aufgaben des W{\"a}rme- und Stoffaustauschs zu l{\"o}sen. Inhalte der Untersuchungen Zur Validierung der Machbarkeit dieser neuen Techniken wurde der Einfluss des elektrischen Windes auf die turbulente Quervermischung, anhand des verbesserten W{\"a}rme- und Stofftransports, sowie des Druckverlusts im Rohrelektroabscheider getestet. Bei den Untersuchungen wurden unterschiedliche Str{\"o}mungsgeschwindigkeiten, Elektrodengeometrien und Betriebsspannungen, sowie die Anwesenheit von Aerosol ber{\"u}cksichtigt. Ein Teil der Ergebnisse diente bereits als Validierungsgrundlage f{\"u}r numerische Simulationen mit einem neuartigen Turbulenzmodell [1]. [1] Medina, J., Schmidt, H., Riebel, U., Application of the one-dimensional turbulence model for electrohydrodynamic variable density flows, 17th European Turbulence Conference, 3-6 September 2019, Torino, Italy}, language = {de} } @misc{BacherRiebel, author = {Bacher, Christian and Riebel, Ulrich}, title = {Einfluss elektrohydrodynamischer Str{\"o}mung auf den W{\"a}rme und Stoff{\"u}bergang in Elektroabscheidern}, series = {ProcessNet 2018, Fachgruppe Gasreinigung}, journal = {ProcessNet 2018, Fachgruppe Gasreinigung}, pages = {1}, abstract = {Zur F{\"o}rderung einer nachhaltigeren Wertsch{\"o}pfungskette werden im Rahmen der Energiewende st{\"a}ndig neue Verfahren und Konzepte zu deren Umsetzung entwickelt. Eines dieser Konzepte befasst sich mit der Zusammenf{\"u}hrung bislang entkoppelter Prozessschritte in Gasreinigungssystemen aus der Energie- und Anlagentechnik. Aus den daraus resultierenden Einsparungen bei den Investitionskosten profitieren nicht nur die klassischen Energieerzeugeuer und Produktionsanlagen in der chemischen Industrie, sondern es werden auch neue Anreize zur dezentralen Energieeinspeisung von kleineren und mittelst{\"a}ndischen Unternehmen gesetzt. Unverzichtbarer Bestandteil dieser Gasreinigungssysteme sind h{\"a}ufig Elektroabscheider, welche weit verbreitet im Einsatz sind um Abgase von St{\"a}uben bzw. Aerosolen zu befreien, oder um Wertprodukte aus Gasstr{\"o}mungen abzuscheiden. Die in Elektroabscheidern prinzipbedingt vorhandenen elektro¬¬hydro¬dyna¬mischen Str{\"o}mungen sollen nun systematisch genutzt werden, um gleichzeitig Aufgaben des W{\"a}rme- und Stoffaustauschs zu l{\"o}sen. Zur Schaffung der notwendigen Auslegungsgrundlagen wurden deshalb qualitative und quantitative Untersuchungen zum Einfluss der elektrohydrodynamischen Str{\"o}mung auf Stoff- und W{\"a}rmetransport in Abh{\"a}ngigkeit von relevanten Betriebsparametern vorgenommen.}, language = {de} } @misc{MedinaMendezBacherSchmidtetal., author = {Medina M{\´e}ndez, Juan Ali and Bacher, Christian and Schmidt, Heiko and Riebel, Ulrich}, title = {EHD-ODT: a stochastic turbulence model for the study of heat and mass transfer in wire-tube electrostatic precipitators}, series = {Jahrestreffen der ProcessNet-Fachgruppen Computational Fluid Dynamics und Gasreinigung}, journal = {Jahrestreffen der ProcessNet-Fachgruppen Computational Fluid Dynamics und Gasreinigung}, publisher = {DECHEMA e.V.}, pages = {2}, language = {en} } @misc{MedinaMendezSchmidtBacheretal., author = {Medina M{\´e}ndez, Juan Ali and Schmidt, Heiko and Bacher, Christian and Riebel, Ulrich}, title = {Electrohydrodynamic-enhanced internal pipe flows from a One-Dimensional Turbulence perspective}, series = {91st Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM)}, volume = {20}, journal = {91st Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM)}, number = {1}, publisher = {Wiley}, doi = {10.1002/pamm.202000132}, pages = {3}, language = {en} } @misc{MedinaMendezSchmidtRiebel, author = {Medina M{\´e}ndez, Juan Ali and Schmidt, Heiko and Riebel, Ulrich}, title = {Towards a One-Dimensional Turbulence Approach for Electrohydrodynamic Flows}, series = {11th International Symposium on Turbulence and Shear Flow Phenomena (TSFP11), Southampton, UK, July 30 to August 2, 2019}, journal = {11th International Symposium on Turbulence and Shear Flow Phenomena (TSFP11), Southampton, UK, July 30 to August 2, 2019}, pages = {1}, language = {en} } @misc{BuergerRiebel, author = {B{\"u}rger, Patrick and Riebel, Ulrich}, title = {Formation of highly resistive SiO2 nanoparticle layers from the aerosol by electrostatic precipitation at 200 °C: Observations on back corona and nanoparticle layer structure}, series = {Journal of Nanoparticle Research}, volume = {23}, journal = {Journal of Nanoparticle Research}, number = {8}, issn = {1572-896X}, doi = {10.1007/s11051-021-05292-4}, language = {en} } @misc{BuergerRiebel, author = {B{\"u}rger, Patrick and Riebel, Ulrich}, title = {High temperature coronas in air and flue gas from LPG combustion: Current-voltage characteristics, ion mobilities and free electrons}, series = {Journal of Electrostatics}, volume = {115}, journal = {Journal of Electrostatics}, issn = {1873-5738}, abstract = {Positive and negative corona discharges were studied at atmospheric pressure in a tube-wire geometry with a tube diameter of 150 mm. Current-voltage characteristics (CVCs) were measured both in air and in flue gas produced with a liquefied petroleum gas (LPG) burner, covering temperatures from ambient up to 1073 K. Corona operation was stable over the whole temperature range with positive polarity and up to 973 K with negative polarity. Based on a detailed analysis of the original CVC measurements, new insights on the temperature-dependent mobility of gas ions, on the occurrence of free electrons and on the electronic current contribution are presented. Deviations from the Townsend theory of CVCs can be ascribed to the lifetime-dependency of ion mobility caused by the formation of cluster ions. The contribution from free electrons is found to depend on temperature and tube radius.}, language = {en} } @misc{BuergerRiebel, author = {B{\"u}rger, Patrick and Riebel, Ulrich}, title = {Feasibility of high-temperature electrostatic precipitation for the removal of nanoparticles: A case study on iron oxide separation at up to 800 ºC}, series = {Journal of Electrostatics}, volume = {120}, journal = {Journal of Electrostatics}, issn = {1873-5738}, doi = {10.1016/j.elstat.2022.103754}, abstract = {The removal of nanoparticles from hot gas streams is a challenging task. However, there is a huge potential for heat recovery from waste gas incineration, glass furnaces, ceramic, metallurgical, pyrolytic and many other high temperature processes. A prototype application is the separation of nanoparticles formed by condensation in thermal post-combustion processes, in order to achieve efficient heat recovery at high temperatures. This case study evaluates the performance of a high-temperature electrostatic precipitator (HT-ESP) between 400 and 800 ºC for both discharge polarities. The tube-type ESP with 150 mm diameter and 1500 mm length is operated isothermally. Two electrode designs are tested by separating flame-generated iron oxide nanoparticles from a flue gas atmosphere. The total number concentration in the raw gas is around 2*107 cm-3 with a temperature-dependent mode diameter of 20-40 nm. Between 400 and 600 ºC very high separation efficiencies around 99.998\% (number-based) were found with just 1.5 s of residence time and negative polarity, using a wire discharge electrode. In fact, the separation is more efficient than at room temperature which is explained by particle charging with free electrons leading to an exceptionally high particle charge. At 700 ºC and 800 ºC, thermionic emissions become more relevant for ESP operation. In this range the best separation efficiencies of 99.96\% and 99.5\% respectively were obtained using a rod discharge electrode operated below the corona onset voltage. The specific input of energy required for 99\% separation efficiency at any temperature is less than 250 J/m3. These findings clearly prove that HT-ESPs are a feasible and highly performing alternative for nanoparticle removal from hot gases at up to 800 ºC.}, language = {en} } @misc{MedinaMendezBacherSchmidtetal., author = {Medina M{\´e}ndez, Juan Ali and Bacher, Christian and Schmidt, Heiko and Riebel, Ulrich}, title = {A dusty gas approach for electrostatic precipitation of monodisperse aerosols using One-Dimensional Turbulence}, series = {4th International Symposium on Multiscale Multiphase Process Engineering (MMPE) 2022, Berlin, Germany, 25-28 September 2022, Book of Abstracts}, journal = {4th International Symposium on Multiscale Multiphase Process Engineering (MMPE) 2022, Berlin, Germany, 25-28 September 2022, Book of Abstracts}, language = {en} } @misc{MedinaMendezBacherSchmidtetal., author = {Medina M{\´e}ndez, Juan Ali and Bacher, Christian and Schmidt, Heiko and Riebel, Ulrich}, title = {A dusty gas approach for electrostatic precipitation of monodisperse aerosols using One-Dimensional Turbulence}, language = {en} } @misc{MedinaMendezBacherRiebeletal., author = {Medina M{\´e}ndez, Juan Ali and Bacher, Christian and Riebel, Ulrich and Schmidt, Heiko}, title = {Electrohydrodynamically-enhanced drag in a vertical pipe-flow with a concentric electrode: A One-Dimensional Turbulence study}, series = {European Journal of Mechanics. B,Fluids}, volume = {95}, journal = {European Journal of Mechanics. B,Fluids}, issn = {1873-7390}, doi = {10.1016/j.euromechflu.2022.05.008}, pages = {240 -- 251}, language = {en} } @misc{BuergerRiebel, author = {B{\"u}rger, Patrick and Riebel, Ulrich}, title = {Effiziente Hochtemperatur-Gasreinigung mittels Elektroabscheider: Zuk{\"u}nftige Anwendungsgebiete zur Wertstoffr{\"u}ckgewinnung und optimierten W{\"a}rme{\"u}bertragung}, series = {Chemie Ingenieur Technik}, volume = {96}, journal = {Chemie Ingenieur Technik}, number = {3}, issn = {0009-286X}, doi = {10.1002/cite.202300153}, pages = {340 -- 346}, abstract = {High-temperature gas cleaning is a challenge, especially when nanoparticles have to be separated from a hot gas stream. Thus, particle separation is often conducted after quenching the gas stream significantly. However, high-temperature particle removal can substantially improve heat recovery in many existing industrial processes, as well as in upcoming pyrolytic processes and the flame-based manufacturing of functional nanoparticles. This contribution describes the experimental results from a pilot-scale high-temperature electrostatic precipitator tasked with the removal of nanoparticles from a flue gas atmosphere between 400-800 °C. Additionally, the underlying phenomena are explained, and the future applications are outlined. Over the whole temperature range a reliable and energy-efficient particle separation was observed. This technology combined with a high-temperature heat exchanger can strongly reduce the primary energy consumption of high-temperature processes.}, language = {de} } @misc{MedinaMendezSchmidtRiebel, author = {Medina M{\´e}ndez, Juan Ali and Schmidt, Heiko and Riebel, Ulrich}, title = {Towards the stochastic modeling of electrostatic precipitators under dusty gas conditions of charged aerosols}, series = {Book of Abstracts zum Jahrestreffen der DECHEMA-Fachgruppen Aerosoltechnik, Gasreinigung, Mehrphasenstr{\"o}mung und Partikelmesstechnik, 28. - 30. M{\"a}rz 2023}, journal = {Book of Abstracts zum Jahrestreffen der DECHEMA-Fachgruppen Aerosoltechnik, Gasreinigung, Mehrphasenstr{\"o}mung und Partikelmesstechnik, 28. - 30. M{\"a}rz 2023}, publisher = {Universit{\"a}t Paderborn}, address = {Paderborn}, pages = {8 -- 9}, language = {en} } @misc{MedinaMendezFistlerOevermannetal., author = {Medina M{\´e}ndez, Juan Ali and Fistler, Marco and Oevermann, Michael and Schmidt, Heiko and Riebel, Ulrich}, title = {Economical map-based turbulence models: Developments and perspectives for the numerical analysis of electrostatic precipitation}, series = {Book of Abstracts PARTEC International Congress on Particle Technology, September 26-28, 2023, N{\"u}rnberg}, journal = {Book of Abstracts PARTEC International Congress on Particle Technology, September 26-28, 2023, N{\"u}rnberg}, publisher = {VDI Verlag GmbH}, address = {D{\"u}sseldorf}, pages = {634 -- 638}, language = {en} }