Records |
Author |
Gonzalez-Quiroga, A.; Kulkarni, S.R.; Vandewalle, L.; Perreault, P.; Goel, C.; Heynderickx, G.J.; van Geem, K.M.; Marin, G.B. |
Title |
Azimuthal and radial flow patterns of 1g-Geldart B-type particles in a gas-solid vortex reactor |
Type |
A1 Journal article |
Year |
2019 |
Publication |
Powder technology |
Abbreviated Journal |
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Volume |
354 |
Issue |
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Pages |
410-422 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000490625500041 |
Publication Date |
2019-06-17 |
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 |
Impact Factor ![sorted by Impact Factor field, ascending order (up)](img/sort_asc.gif) |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
Call Number |
UA @ admin @ c:irua:162120 |
Serial |
7543 |
Permanent link to this record |
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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. |
Title |
An experimental and numerical study of the suppression of jets, counterflow, and backflow in vortex units |
Type |
A1 Journal article |
Year |
2019 |
Publication |
AIChE journal |
Abbreviated Journal |
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Volume |
65 |
Issue |
8 |
Pages |
e16614-13 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Language |
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Wos |
000474620800026 |
Publication Date |
2019-04-19 |
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 |
Impact Factor ![sorted by Impact Factor field, ascending order (up)](img/sort_asc.gif) |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
Call Number |
UA @ admin @ c:irua:162121 |
Serial |
7945 |
Permanent link to this record |
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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. |
Title |
Biomass fast pyrolysis in an innovative gas-solid vortex reactor : experimental proof of concept |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Journal Of Analytical And Applied Pyrolysis |
Abbreviated Journal |
J Anal Appl Pyrol |
Volume |
156 |
Issue |
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Pages |
105165-12 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000663091200002 |
Publication Date |
2021-04-16 |
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 |
0165-2370 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor ![sorted by Impact Factor field, ascending order (up)](img/sort_asc.gif) |
3.471 |
Times cited |
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Open Access |
OpenAccess |
Notes |
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Approved |
Most recent IF: 3.471 |
Call Number |
UA @ admin @ c:irua:178743 |
Serial |
7562 |
Permanent link to this record |