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Item type:Publication, Access status: without files , Characterization of the pneumatic behavior of a novel spouted bed apparatus(2008-05); ; ; ; Recently the importance of spouted bed technology has significantly increased in the context of drying processes as well as granulation, agglomeration or coating processes. Par-ticulate systems concerning very fine or non spherical particles that are difficult to fluidize, often cannot be treated in conventional fluidized beds. In contrast to those fluidized beds, the spouted bed technology with its specific flow structure offers the opportunity of stable fluidization under controlled conditions. Within this work the fluid dynamics of a novel spouted bed with two adjustable gas inlets is investigated. By analysis of gas fluctuation spectra by means of a fast Fourier transformation algorithm, different operation regimes are identified and depicted graphically. Furthermore, continuum CFD-modeling of the granular solid phase motion by means of an Euler/Euler approach and comparisons with experimental obtained velocity vector fields by means of particle image velocimetry (PIV) measurements will be presented in this work.Publicationtype: Conference Paper10 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , A discrete particle simulation study on the influence of restitution coefficient on spout fluidized bed dynamicsIn this paper the influence of the normal restitution coefficient on the bed dynamics during different flow regimes was studied using the discrete element model. The three flow regimes comprise the intermediate/spout- fluidization, spouting-with-aeration regime and the jet-in-fluidized-bed. It is shown that with increase of the restitution coefficient the average bed height decreases for all flow regime cases. To study the influence of the granule impact velocity and the liquid film on the wall surface the free-fall experiments in the velocity range of 0.5-4.5 m/s were performed with spherical γ-Al2O3 granules. During the free-fall tests, the impact angle from 0° to 80° and the viscosity of thin liquid film in the range of 1-300 mPa·s were varied.Publicationtype: Conference Paper32 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Controlled addition of reactants in a fluidized bed membrane reactor(2008-05); ; ; The focus of this contribution was to evaluate the membrane reactor concept in fluidized beds. The performance of a pilot-plant fluidized bed membrane reactor (FLBMR) was studied experimentally in comparison to the conventional operation as a fluidized bed reactor (FLBR). As model reaction was applied the catalytic oxidative dehydrogenation of ethane using a γ-alumina supported vanadium oxide catalyst. The beneficial effect of oxidant dosing over the membrane is most pronounced at high temperatures and long contact times.Publicationtype: Conference Paper30 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Particle formulation by means of fluidized bed granulation: Influence of the process parameters on the material properties of the granules(2008-05); ; For the fluidized bed granulation the influence of process parameters on the material properties of the granules have been studied. A decreasing strength of the products with rising binder content in the injected liquid was found. On the other hand an increased binder content leads to a better granulation. Furthermore, it was shown that the retention time of the particles in the fluidized bed has an influence on the strength of the product, especially during the first minutes of fluidization. The moisture content of the granules in the case of this fluidized bed spray granulation seems to be negligible. In spite of different liquid injection rates, the moisture content of the particles was very dry (<< 1 mass-%).Publicationtype: Conference Paper27