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Author |
Lang, X.; Ouyang, Y.; Vandewalle, L.A.; Goshayeshi, B.; Chen, S.; Madanikashani, S.; Perreault, P.; Van Geem, K.M.; van Geem, K.M. |
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Title |
Gas-solid hydrodynamics in a stator-rotor vortex chamber reactor |
Type |
A1 Journal article |
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Year  |
2022 |
Publication |
Chemical engineering journal |
Abbreviated Journal |
Chem Eng J |
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Volume |
446 |
Issue |
5 |
Pages |
137323-12 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
The gas-solid vortex reactor (GSVR) has enormous process intensification potential. However the huge gas consumption can be a serious disadvantage for the GSVR in some applications such as fast pyrolysis. In this work, we demonstrate a recent novel design, where a stator-rotor vortex chamber (STARVOC) is driven by the fluid's kinetic energy, to decouple the solids bed rotation and gas. Gas-solid fluidization by using air and monosized aluminum balls was performed to investigate the hydrodynamics. A constructed fluidization flow regime map for a fixed solids loading of 100 g shows that the bed can only be fluidized for a rotation speed between 200 and 400 RPM. Below 200 RPM, particles settle down on the bottom plate and cannot form a stable bed due to inertia and friction. Above 400 RPM, the bed cannot be fluidized with superficial velocities up to 1.8 m/s (air flow rate of 90 Nm(3)/h). The bed thickness shows some non-uniformities, being smaller at the top of the bed than at the bottom counterpart. However by increasing the air flow rate or rotation speed the axial nonuniformity can be resolved. The bed pressure drop first increases with increasing gas flow rate and then levels off, showing similar characteristics as conventional fluidized beds. Theoretical pressure drops calculated from mathematical models such as Kao et al. model agree well with experimental measurements. Particle velocity discrepancies between the top and bottom particles reveal that the impact of gravity cannot be completely neglected. Design guidelines and possible applications for further development of STARVOC concept are proposed based on fundamental data provided in this work. |
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Wos |
000833418100006 |
Publication Date |
2022-06-01 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1385-8947; 1873-3212 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
15.1 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 15.1 |
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Call Number |
UA @ admin @ c:irua:189283 |
Serial |
7167 |
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Author |
Gonzalez-Quiroga, A.; Shtern, V.; Perreault, P.; Vandewalle, L.; Marin, G.B.; Van Geem, K.M. |
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Title |
Intensifying mass and heat transfer using a high-g stator-rotor vortex chamber |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Chemical Engineering And Processing |
Abbreviated Journal |
Chem Eng Process |
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Volume |
169 |
Issue |
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Pages |
108638-11 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Vortex reactors take advantage of the synergy between enhanced heat and mass transfer rates and multifunctional phenomena at different temporal and spatial scales. Proof-of-concept experiments with our novel and innovative STAtor-Rotor VOrtex Chamber (STARVOC) confirm its advantageous features for the sustainable production of chemicals and fuels. STARVOC is a high-g contactor that uses carrier flow (gas or liquid) tangential injection to drive a rotor attached to low-friction bearings. The vortex chamber inside the rotor contains a secondary phase or phases, such as a solids bed, a liquid layer, or a suspension. Carrier fluid passes through the perforated rotor wall and contacts a densely and uniformly distributed secondary phase with enhanced slip velocities. Experiments focused on pressure profiles, rotor angular velocity, and solids azimuthal velocity. With air as the carrier fluid and different solid particle beds as the secondary phase, STARVOC reached bed azimuthal velocities up to four-fold compared to those reached in Gas-Solid Vortex Units with fully static geometry. These results show its potential to improve interfacial heat and mass transfer rates and take advantage of flow energy and angular momentum. Due to its process intensification capabilities, STARVOC is a promising alternative for the state-of-the-art chemical industry. |
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Wos |
000704946900008 |
Publication Date |
2021-09-17 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0255-2701 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.234 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: 2.234 |
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Call Number |
UA @ admin @ c:irua:181062 |
Serial |
8111 |
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Author |
Larraín, M.; Van Passel, S.; Thomassen, G.; Van Gorp, B.; Nhu, T.T.; Huysveld, S.; Van Geem, K.M.; De Meester, S.; Billen, P. |
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Title |
Techno-economic assessment of mechanical recycling of challenging post-consumer plastic packaging waste |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Resources Conservation And Recycling |
Abbreviated Journal |
Resour Conserv Recy |
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Volume |
170 |
Issue |
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Pages |
105607 |
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Keywords |
A1 Journal article; Economics; Engineering sciences. Technology; Engineering Management (ENM); Intelligence in PRocesses, Advanced Catalysts and Solvents (iPRACS) |
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Abstract |
Increasing plastic recycling rates is crucial to tackle plastic pollution and reduce consumption of fossil resources. Recycling routes for post-consumer plastic fractions that are technologically and economically feasible remain a challenge. Profitable value chains for recycling mixed film and tray-like plastics have hardly been implemented today, in sharp contrast to recycling of relatively pure fractions such as polyethylene terephthalate and high-density polyethylene bottles. This study examines the economic feasibility of implementing mechanical recycling for plastic waste such as polypropylene, polystyrene, polyethylene films and mixed polyolefins. In most European countries these plastic fractions are usually incinerated or landfilled whilst in fact technologies exist to mechanically recycle them into regranulates or regrinds. Results show that the economic incentives for the recycling of plastic packaging depend predominantly on the product price and product yield. At current price levels, the most profitable plastic fraction to be recycled is PS rigids, with an internal rate of return of 14%, whereas the least profitable feed is a mixed polyolefin fraction with a negative internal rate of return in a scenario with steadily rising oil prices. Moreover, these values would be substantially reduced if oil prices, and therefore plastic product prices decrease. Considering a discount rate of 15% for a 15-year period, mechanical recycling is not profitable if no policy changes would be imposed by governments. Clearly low oil prices may jeopardize the mechanical recycling industry, inducing the need for policies that would increase the demand of recycled products such as imposing minimal recycled content targets. |
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Wos |
000667309200042 |
Publication Date |
2021-04-20 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0921-3449 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.313 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 3.313 |
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Call Number |
UA @ admin @ c:irua:177325 |
Serial |
6946 |
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Author |
Nunez Manzano, M.; Gonzalez Quiroga, A.; Perreault, P.; Madanikashani, S.; Vandewalle, L.A.; Marin, G.B.; Heynderickx, G.J.; Van Geem, K.M. |
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Title |
Biomass fast pyrolysis in an innovative gas-solid vortex reactor : experimental proof of concept |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Journal Of Analytical And Applied Pyrolysis |
Abbreviated Journal |
J Anal Appl Pyrol |
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Volume |
156 |
Issue |
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Pages |
105165-12 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Biomass fast pyrolysis has been considered one of the best alternatives for the thermal conversion of biomass into bio-oil. This work introduces a new reactor technology for biomass fast pyrolysis, the Gas-Solid Vortex Reactor (GSVR), to obtain high bio-oil yields. The GSVR was designed to decrease the residence time of the pyrolysis vapors; thus, the secondary cracking reactions are reduced, to enhance the segregation of the char and the unreacted biomass and to improve the heat transfer rate. Biomass fast pyrolysis experiments have been carried out for the first time in a Gas-Solid Vortex Reactor (GSVR) at 773 K, using softwood (pine) and hardwood (poplar) as feedstock. Char yields as low as 10 wt. % in the GSVR were comparable to those reported for the same feedstocks processed in conventional fluidized bed reactors. The yields of non-condensable gases in the range of 15–17 wt. % were significantly lower than those reported for other commonly used biomass fast pyrolysis reactors. Two-dimensional gas chromatography (GC × GC) revealed noticeable differences at the molecular level between the bio-oils from the GSVR and bio-oils from other reactors. The aromatics in the pine bio-oil consist almost entirely (85 wt. %) of guaiacols. For poplar bio-oils no predominant group of aromatics was found, but phenolics, syringols, and catechols were the most pronounced. The experimental results highlight the advantages of the GSVR for biomass pyrolysis, reaching stable operation in around 60 s, removing the formed char selectively during operation, and enabling fast entrainment of pyrolysis vapors. Results indicate a great potential for increasing yield and selectivity towards guaiacols in softwood (e.g., pine) bio-oil. Likewise, decreasing pyrolysis temperature could increase the yield of guaiacols and syringols in hardwood (e.g., poplar) bio-oil. |
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Wos |
000663091200002 |
Publication Date |
2021-04-16 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0165-2370 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.471 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 3.471 |
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Call Number |
UA @ admin @ c:irua:178743 |
Serial |
7562 |
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Author |
Kleinhans, K.; Hallemans, M.; Huysveld, S.; Thomassen, G.; Ragaert, K.; Van Geem, K.M.; Roosen, M.; Mys, N.; Dewulf, J.; De Meester, S. |
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Title |
Development and application of a predictive modelling approach for household packaging waste flows in sorting facilities |
Type |
A1 Journal Article |
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Year |
2021 |
Publication |
Waste Management |
Abbreviated Journal |
Waste Management |
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Volume |
120 |
Issue |
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Pages |
290-302 |
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Keywords |
A1 Journal Article; Engineering Management (ENM) ; |
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Abstract |
Household packaging waste sorting facilities consist of complex networks of processes to separate diverse waste streams. These facilities are a key first step to re-enter materials into the recycling chain. However, so far there are no general methods to predict the performance of such sorting facilities, i.e.
how efficiently the heterogeneous packaging waste is sorted into fractions with value for further recycling. In this paper, a model of the material flow in a sorting facility is presented, which allows changing the incoming waste composition, split factors on the sorting units as well as the setup of the sorting facility. The performance of the sorting facility is judged based on the purity of the output material (grade) and the recovery of the input material. A validation of the model was performed via a case study on Belgian post-consumer packaging waste with a selection of typical waste items that can be found in this stream. Moreover, the model was used to predict the possible sorting qualities of future Belgian postconsumer packaging waste after an extension of the allowed waste packaging items in the waste stream. Finally, a sensitivity analysis was performed on the split factors, which are a key data source in the model. Overall, the developed model is flexible and able to predict the performance of packaging waste sorting facilities as well as support waste management and design for recycling decisions, including future
design of packaging, to ensure proper sorting and separation. |
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Publication Date |
2020-12-16 |
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Abbreviated Series Title |
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Edition |
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ISSN |
0956053X |
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Times cited |
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Not_Open_Access |
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Notes |
We would like to thank Indaver (https://www.indaver.com/been/home/), especially Erik Huybrechts, Eric Goddaert, Eline Meyvis and Erik Moerman, for their great support on this research. Furthermore, we would like to acknowledge the help of Colruyt (https://www.colruyt.be/) and CEFLEX (https://ceflex.eu/) for the pre-studies for this research. Moreover, we would like to show our appreciation for the financial support by the Catalisti-ICON project (HBC.2018.0262) MATTER (Mechanical and Thermochemical Recycling of mixed plastic waste) funded by Flanders Innovation & Entrepreneurship (VLAIO). We also thank the Interreg 2 Seas program PlastiCity that is co-funded by the European Regional Development Fund under subsidy contract No. 2S05-021 and the province of East-Flanders for funding this research. |
Approved |
Most recent IF: NA |
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Call Number |
ENM @ enm @ |
Serial |
6667 |
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Author |
Vandewalle, L.A.; Gonzalez-Quiroga, A.; Perreault, P.; Van Geem, K.M.; Marin, G.B. |
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Title |
Process intensification in a gas–solid vortex unit : computational fluid dynamics model based analysis and design |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Industrial and engineering chemistry research |
Abbreviated Journal |
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Volume |
58 |
Issue |
28 |
Pages |
12751-12765 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
The process intensification abilities of gas–solid vortex units (GSVU) are very promising for gas–solid processes. By working in a centrifugal force field, much higher gas–solid slip velocities can be obtained compared to gravitational fluidized beds, resulting in a significant increase in heat and mass transfer rates. In this work, local azimuthal and radial particle velocities for an experimental GSVU are simulated using the Euler–Euler framework in OpenFOAM and compared with particle image velocimetry measurements. With the validated model, the effect of the particle diameter, number of inlet slots and reactor length on the bed hydrodynamics is assessed. Starting from 1g-Geldart-B type particles, increasing the particle diameter or density, increasing the number of inlet slots or increasing the gas injection velocity leads to an increased bed stability and uniformity. However, a trade-off has to be made since increased bed stability and uniformity lead to higher shear stresses and attrition. |
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Wos |
000476686000027 |
Publication Date |
2019-06-19 |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0888-5885; 1520-5045 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:162122 |
Serial |
8416 |
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Author |
Gonzalez-Quiroga, A.; Kulkarni, S.R.; Vandewalle, L.; Perreault, P.; Goel, C.; Heynderickx, G.J.; van Geem, K.M.; Marin, G.B. |
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Title |
Azimuthal and radial flow patterns of 1g-Geldart B-type particles in a gas-solid vortex reactor |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Powder technology |
Abbreviated Journal |
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Volume |
354 |
Issue |
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Pages |
410-422 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Processes requiring intensive interfacial momentum, mass and heat exchange between gases and particulate solids can be greatly enhanced by operating in a centrifugal field. This is realized in the Gas-Solid Vortex Reactor (GSVR) with centrifugal accelerations up to two orders of magnitude higher than the Earth's gravitational acceleration. Here, the flow patterns of two 1g-Geldart B-type particles are experimentally assessed, over the gas inlet velocity range 82–126 m s−1, in an 80 mm diameter and 15 mm height GSVR. The particles are monosized aluminum spheres of 0.5 mm diameter, and walnut shell in the sieve fraction 0.50–0.56 mm and aspect ratio 1.3 ± 0.2. Two dimensional Particle Image Velocimetry combined with Digital Image Analysis and pressure measurements revealed that periodic fluctuations in solids azimuthal and radial velocity between gas inlet slots are strongly related to the average solids azimuthal velocity and bed uniformity. Aluminum particles feature steeper changes in azimuthal velocity and more attenuated changes in radial velocity than walnut shell particles. Within the assessed gas inlet velocity range the solids bed of aluminum exhibits average azimuthal velocities and bed voidages 40–50% and ≈10% lower than those of walnut shell. The aerodynamic response time of the particles, i.e. ρsdp2/18μg, emerged as an important parameter to assess the influence of the carrier gas jet on the radial deflection of the particles and the interaction solids bed-outer wall. Too low aerodynamic response time relates to nonuniformity in bed voidage due to solids radial velocity fluctuations. Excessive aerodynamic response time indicates low solids azimuthal velocities due to solids bed-outer wall friction. |
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Wos |
000490625500041 |
Publication Date |
2019-06-17 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0032-5910 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:162120 |
Serial |
7543 |
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Author |
Kulkarni, S.; Gonzalez-Quiroga, A.; Nuñez, M.; Schuerewegen, C.; Perreault, P.; Goel, C.; Heynderickx, G.J.; Van Geem, K.M.; Marin, G.B. |
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Title |
An experimental and numerical study of the suppression of jets, counterflow, and backflow in vortex units |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
AIChE journal |
Abbreviated Journal |
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Volume |
65 |
Issue |
8 |
Pages |
e16614-13 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Vortex units are commonly considered for various single and multiphase applications due to their process intensification capabilities. The transition from gas‐only flow to gas–solid flow remains largely unexplored nonetheless. During this transition, primary flow phenomenon, jets, and secondary flow phenomena, counterflow and backflow, are substantially reduced, before a rotating solids bed is established. This transitional flow regime is referred to as the vortex suppression regime. In the present work, this flow transition is identified and validated through experimental and computational studies in two vortex units with a scale differing by a factor of 2, using spherical aluminum and alumina particles. This experimental data supports the proposed theoretical particle monolayer solids loading that allows estimation of vortex suppression regime solids capacity for any vortex unit. It is shown that the vortex suppression regime is established at a solids loading theoretically corresponding to a monolayer being formed in the unit for 1g‐Geldart D‐ and 1g‐Geldart B‐type particles. The model closely agrees with experimental vortex suppression range for both aluminum and alumina particles. The model, as well as the experimental data, shows that the flow suppression regime depends on unit dimensions, particle diameter, and particle density but is independent of gas flow rate. This combined study, based on experimental and computational data and on a theoretical model, reveals the vortex suppression to be one of the basic operational parameters to study flow in a vortex unit and that a simple monolayer model allows to estimate the needed solids loading for any vortex device to induce this flow transition. |
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Place of Publication |
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Wos |
000474620800026 |
Publication Date |
2019-04-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0001-1541 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:162121 |
Serial |
7945 |
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