12 results
Now showing1 - 10 of 12
- Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Powering mobile sensor nodes in fluidized beds: A non-invasive RF energy harvesting proof-of-concept(American Chemical Society (ACS), 2026-10-16); ; ; ; Real-time monitoring within industrial processing vessels is essential for advancing process analytical technology. Flow-following sensors represent an ideal approach for delivering continuous, in-line data from the process stream. However, deploying these mobile sensors is constrained by the physical barriers of sealed metallic vessels and harsh, battery-hostile environments. To overcome these limitations, a non-invasive, retrofittable wireless power transfer system is presented. The metallic vessel is structurally repurposed into a 5.23 GHz multi-mode microwave cavity resonator by coupling microwave energy through existing standard flanges. Electromagnetic simulations validate that this method generates continuous energy coverage throughout dynamic flow zones, demonstrated using a fluidized bed granulator as an application example. To harness this energy, an omnidirectional antenna and a compact RF-to-DC rectifier prototype were developed. By enabling the continuous operation of autonomous, battery-free mobile sensor nodes, this framework provides a practical, scalable foundation for high-density spatial analytics and data-driven industrial optimization.Publicationtype: Journal Article10 7 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Impedance spectroscopy for multi-state analysis of dissolvable powders: determining layer thickness and moisture content(Elsevier, 2026-03-27); ; ; ; This study presents a novel methodology for applying Electrical Impedance Spectroscopy to analyze the electrical properties of dissolvable powders, when applied as a coating layer to quantify their thickness and moisture content. To address challenges posed by undefined geometries, powders were dissolved and applied as coatings on custom-designed Printed Circuit Board electrodes. Using sodium benzoate as a model material, the drying process was monitored in off-line measurements, revealing distinct transitions in electrical properties. Impedance and phase angle measurements effectively tracked moisture reduction during drying, while coating thickness and solution concentration also influenced conductivity. The findings demonstrate the potential of this approach for industrial applications, such as fluidized bed spray granulation, by enabling real-time monitoring of drying states.Publicationtype: Journal Article62 129 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Modelling the breakage of coated particles using discrete element and bonded particle methodIn recent years, particles have gained popularity as crash absorbers. To improve their mechanical properties, a coating layer can be applied. To predict the effect of this coating, a numerical model must be developed. For this purpose, the present study employs the discrete element method, extended by the bonded particle method, using both high- and low-fidelity approaches. In this framework, a single physical particle is modelled as a cluster or agglomerate of smaller particles bonded together. To identify the parameters involved, a sensitivity analysis is performed, followed by optimisation using the particle swarm algorithm, with calibration based on uniaxial single particle compression tests. Once an optimised parameter set is obtained, the models are validated against multi particle compression test results. The outcomes of this study demonstrate the potential of the proposed methodology for simulating large-scale compression tests of coated granular materials.Publicationtype: Journal Article26 20 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Influence of spray parameters on injected droplets and product properties in fluidized bed spray granulationLiquid injection is one of the, if not the most, critical steps in fluidized bed spray granulation as the product quality as well as the overall process stability can be massively influenced by the associated parameters. Therefore, this study aims to correlate spray parameters to the spray pattern and droplets produced from the nozzle and the resulting granule properties. First, the effect of spray variables on spray angle and droplet size and velocity was analyzed, revealing the spray air pressure as crucial parameter. Afterwards, spray agglomeration experiments were conducted according to a statistical experimental plan varying several process-related parameters in addition to the nozzle set-up. The product particle size distribution was shown to be impacted by a complex combination of the investigated variables with the liquid spray rate, spray and protection air pressure, and fluidization air flow as main influences.Publicationtype: Journal Article62 50 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , CFD-DEM modeling for optimized liquid distribution in fluidized bed spray granulation(Elsevier, 2024-09-19); ; ; ; In this work, CFD-DEM simulations of two different fluidized bed granulator geometries were performed, aiming to provide an insight into how the injected liquid behaves within the particle bed and thus an overall better understanding of the granulation process itself. Simulation results were evaluated regarding the fate of sprayed droplets, e.g. deposition on a particle, elutriation from fluidized bed, or collision with apparatus walls. For the deposited droplets, the particle–droplet collisions were tracked in order to obtain a locally resolved deposition rate. Spray parameters as well as geometric specifications of the nozzle setup were varied, investigating a broad range of different process conditions. By optimizing apparatus design, especially the air inlet, an even distribution of the liquid droplets within the fluidized bed and overall higher deposition rate can be achieved and a stable steady state with a well-defined spray zone is reached within a broad range of varied spray parameters.Publicationtype: Journal Article49 55 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Simulation of the mechanical behaviour of coated particles using DEM‐BPMIn previous years, research into the use of granular media as crash absorbers in a ship double hull has led to an increased interest in further optimisation to improve their energy absorption. One way is to add a coating layer on the outside surface of these particles. This work provides an introduction to the numerical modelling of coated particles to simulate their crushing behaviour. Depending upon the type of coating material, the compressive behaviour differs. Therefore, a sound methodology needs to be developed. For that purpose, the discrete element method in combination with the bonded particle method was utilised using the open‐source code MUSEN. The bonded particle method helps to simulate the crushing behaviour of coated particles. However, for this high‐fidelity model, the number of parameters needs to be reduced and afterwards optimised. A sensitivity analysis is performed for that objective followed by optimisation using particle swarm algorithm. The results illustrate a good approximation of the experimental force‐displacement curve by the optimised model on a uniaxial single particle compression test.Publicationtype: Journal Article14 51 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Fluidized bed spray coating for improved mechanical properties of particles(Multidisciplinary Digital Publishing Institute (MDPI), 2023-01-18); ; ; ; When designing crash absorber particles for application as a filling material in the double-hull of ships, the main goal is to achieve an optimal mechanical performance, in combination with a low-density particle structure, while fulfilling several additional requirements regarding, for example, non-toxic and hydrophobic behavior. In this study, a fluidized bed was used to coat Poraver® glass particles with Candelilla wax and silicone to attain these specifications. A uniform coating was achieved with wax, but the process turned out to be far more challenging when using silicone. To evaluate the suitability of coated particles as a granular filling material, and to compare their performances with that of untreated Poraver® particles, several mechanical tests, as well as structural investigations, were conducted. While no notable improvement in mechanical behavior was observed on the single-particle level, bulk tests showed promising results regarding compressibility and abrasion resistance of coated particles compared to untreated ones.Publicationtype: Journal Article120 164 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Influence of nozzle parameters on spray pattern and droplet characteristics for a two-fluid nozzleIn this study, a two-fluid nozzle, as, e.g., used in fluidized-bed or spray drying applications, is comprehensively characterized regarding the spray pattern and droplet size. To analyze the spray cone, the spray cone angle and the radial mass distribution of the nozzle were measured at varied liquid flow rate, spray air pressure, liquid insert bore diameter, and air cap position. Additionally, droplet size distributions were recorded at different spray settings. In general, the overall spray cone and single droplets are significantly influenced by the spray parameters, especially the spray air pressure, as well as the nozzle geometry.Publicationtype: Journal ArticleScopus© Citations 3 169 207 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Workshop GRK 2462 "Processes in Natural and Technical Particle-Fluid-Systems" (PintPFS) : 26th & 27th of September 2022, Hamburg, Germany : conference proceedings(2022-09-26); ; ; ; In the framework of Research Training Group GRK 2462 “Processes in Natural and Technical Particle-Fluid-Systems” (PintPFS), funded by the German Research Foundation (DFG), researchers from the fields of civil engineering, mechanical engineering, process engineering, and materials sciences investigate natural and technical Particle-Fluid-Systems (PFS) in an interdisciplinary approach. As PFS are ubiquitous in everyday life and relevant for many processes in industry, pharmacy, and food production, they represent a fascinating field of research with potential for promising and useful discoveries in many aspects.Publicationtype: Conference Proceedings407 2182 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Correlating granule surface structure morphology and process conditions in fluidized bed layering spray granulationA workflow for developing a multidimensional, linear correlation between the process conditions during fluidized bed spray granulation and the surface morphology of the resulting granules is presented. Spray coating experiments with Cellets®500 particles and sodium benzoate solution were performed in a lab-scale fluidized bed varying liquid spray rate, fluidization air flow rate, fluidization air temperature, spray air temperature and spray atomization pressure. To characterize the surface structure, the surface roughness of the coated particles was quantified using confocal laser-scanning microscopy. The roughness was correlated to the process conditions, and the resulting correlation was rigorously analyzed for the importance and co-linearities of the individual process parameters using a principal component analysis. The surface roughness is strongly dependent on the spray rate of the coating solution, the fluidization air temperature and the atomization pressure at the nozzle. In general, wet process conditions and large droplets with a low initial velocity favor the formation of particles with a rough surface structure, while dry conditions and fine droplets with a high velocity result in granules with a smooth and compact coating layer.Publicationtype: Journal ArticleScopus© Citations 5 159 229