Effects of Riser Diameter on Solids Holdup and Particle Velocity Profiles in Circulating Fluidized Bed Riser Systems

Breault, Ronald W.; Rowan, Steven L.; Weber, Justin M.; Yang, Jingsi

doi:10.1115/1.4046139

Title: Effects of Riser Diameter on Solids Holdup and Particle Velocity Profiles in Circulating Fluidized Bed Riser Systems

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Abstract

Tests were performed in a 0.1-m diameter small circulating fluidized bed (SCFB) and 0.3 m diameter cold flow circulating fluidized bed (CFCFB) riser systems located at the National Energy Technology Laboratory (NETL) to study the effects of riser diameter on the riser hydrodynamics. These tests were performed at solids circulation rates of G_s = 20 and 75 kg/m² s and superficial gas velocities of U_g = 5.8 and 6.5 m/s using high-density polyethylene (HDPE) pellets with a density of 0.863 g/cm³, particle size range of 600–1400 µm (with a Sauter mean diameter of 871 µm, placing them in the Geldart B classification). Comparisons of riser axial pressure and solids fraction profiles, radial particle velocity profiles, and radial profiles of higher statistical moments and select chaos analysis parameters were considered. The results showed that for a given U_g and G_s, the smaller diameter riser exhibited characteristics associated with more dilute solids flow than that observed in the larger diameter riser. Additionally, the larger diameter riser exhibited a downward flow of solids near the wall under all test conditions, whereas the smaller diameter riser data exhibited little or no indications of solids downflow near the wall. Overall, these findings suggest that, frommore »« less

Authors:

Breault, Ronald W. ^[1]; Rowan, Steven L. ^[2]; Weber, Justin M. ^[1]; Yang, Jingsi ^[2]

National Energy Technology Lab. (NETL), Morgantown, WV (United States)
Oak Ridge Inst. for Science and Education (ORISE), Morgantown, WV (United States)

Publication Date:: Fri Feb 28 00:00:00 EST 2020

Research Org.:: National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV, and Albany, OR (United States)

Sponsoring Org.:: USDOE Office of Fossil Energy (FE)

OSTI Identifier:: 1763900

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Energy Resources Technology

Additional Journal Information:: Journal Volume: 142; Journal Issue: 7; Journal ID: ISSN 0195-0738

Publisher:: ASME

Country of Publication:: United States

Language:: English

Subject:: 42 ENGINEERING

Citation Formats


                    Breault, Ronald W., Rowan, Steven L., Weber, Justin M., and Yang, Jingsi. Effects of Riser Diameter on Solids Holdup and Particle Velocity Profiles in Circulating Fluidized Bed Riser Systems.  United States: N. p., 2020. 
Web.  doi:10.1115/1.4046139.

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                    Breault, Ronald W., Rowan, Steven L., Weber, Justin M., & Yang, Jingsi. Effects of Riser Diameter on Solids Holdup and Particle Velocity Profiles in Circulating Fluidized Bed Riser Systems.  United States.  https://doi.org/10.1115/1.4046139

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                    Breault, Ronald W., Rowan, Steven L., Weber, Justin M., and Yang, Jingsi. Fri .  
"Effects of Riser Diameter on Solids Holdup and Particle Velocity Profiles in Circulating Fluidized Bed Riser Systems".  United States.  https://doi.org/10.1115/1.4046139.  https://www.osti.gov/servlets/purl/1763900.

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@article{osti_1763900,

  title        = {Effects of Riser Diameter on Solids Holdup and Particle Velocity Profiles in Circulating Fluidized Bed Riser Systems},

  author       = {Breault, Ronald W. and Rowan, Steven L. and Weber, Justin M. and Yang, Jingsi},

  abstractNote = {Tests were performed in a 0.1-m diameter small circulating fluidized bed (SCFB) and 0.3 m diameter cold flow circulating fluidized bed (CFCFB) riser systems located at the National Energy Technology Laboratory (NETL) to study the effects of riser diameter on the riser hydrodynamics. These tests were performed at solids circulation rates of Gs = 20 and 75 kg/m2 s and superficial gas velocities of Ug = 5.8 and 6.5 m/s using high-density polyethylene (HDPE) pellets with a density of 0.863 g/cm3, particle size range of 600–1400 µm (with a Sauter mean diameter of 871 µm, placing them in the Geldart B classification). Comparisons of riser axial pressure and solids fraction profiles, radial particle velocity profiles, and radial profiles of higher statistical moments and select chaos analysis parameters were considered. The results showed that for a given Ug and Gs, the smaller diameter riser exhibited characteristics associated with more dilute solids flow than that observed in the larger diameter riser. Additionally, the larger diameter riser exhibited a downward flow of solids near the wall under all test conditions, whereas the smaller diameter riser data exhibited little or no indications of solids downflow near the wall. Overall, these findings suggest that, from an industrial standpoint, a direct scaleup of small-scale tests cannot readily be accomplished as the solids holdup and the solids velocity profiles in small units (those normally tested in the laboratory) are not similar to those of large units and the performance of large units can therefore not be predicted from small-scale tests.},

  doi          = {10.1115/1.4046139},

  journal      = {Journal of Energy Resources Technology},

  number       = 7,

  volume       = 142,

  place        = {United States},

  year         = {Fri Feb 28 00:00:00 EST 2020},

  month        = {Fri Feb 28 00:00:00 EST 2020}

}

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