The assessment of the solids flow in the riser of a Circulating Fluidized Bed (CFB) through positron imaging

M. Van De Velden; J. Baeyens; J. P.K. Seville; X. Fan

The assessment of the solids flow in the riser of a Circulating Fluidized Bed (CFB) through positron imaging

M. Van De Velden^*, J. Baeyens, J. P.K. Seville, X. Fan

^*Corresponding author for this work

School of Engineering

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

Abstract

Circulating Fluidized Beds (CFB) are attracting increasing interest for both gas-solid and gas-catalytic reactions, although operating modes differ completely. To model the reactor, the knowledge of the solids residence time is an important parameter. Previous studies mostly assess operations at moderate values of the solids circulation rates (≤ 100 kg/m²s), whereas gas-catalytic reactions and biomass pyrolysis require completely different operating conditions. Positron Emission Particle Tracking (PEPT) is used to study the movement and population density of particles in the CFB-riser. Transformation of the PEPT results define (i) the vertical particle movement and population density in a cross sectional area of the riser; (ii) the required transport gas velocity (U_tr) to operate in a fully established circulation mode; (iii) the overall particle movement mode (plug flow vs. core/annulus flow); and (iv) the particle slip velocity. Only in a plug flow mode can the particle slip velocity be estimated from the difference of superficial gas velocity and particle terminal velocity. The slip velocity is lower than U - U_tr outside the plug flow mode. To operate in plug flow, the superficial gas velocity should exceed U_tr by 1 m/s and the solids circulation rate should exceed 200 kg/m²s.

Original language	English
Title of host publication	CHISA 2006 - 17th International Congress of Chemical and Process Engineering
Publication status	Published - 1 Dec 2006
Event	CHISA 2006 - 17th International Congress of Chemical and Process Engineering - Prague, Czech Republic Duration: 27 Aug 2006 → 31 Aug 2006

Publication series

Name	CHISA 2006 - 17th International Congress of Chemical and Process Engineering

Conference

Conference	CHISA 2006 - 17th International Congress of Chemical and Process Engineering
Country/Territory	Czech Republic
City	Prague
Period	27/08/06 → 31/08/06

Keywords / Materials (for Non-textual outputs)

Circulating fluidized bed
Plug flow
Positron tracking
Tracer
Velocities

Cite this

@inproceedings{6149d1919f5447ce987d0fc7e48b34bd,

title = "The assessment of the solids flow in the riser of a Circulating Fluidized Bed (CFB) through positron imaging",

abstract = "Circulating Fluidized Beds (CFB) are attracting increasing interest for both gas-solid and gas-catalytic reactions, although operating modes differ completely. To model the reactor, the knowledge of the solids residence time is an important parameter. Previous studies mostly assess operations at moderate values of the solids circulation rates (≤ 100 kg/m2s), whereas gas-catalytic reactions and biomass pyrolysis require completely different operating conditions. Positron Emission Particle Tracking (PEPT) is used to study the movement and population density of particles in the CFB-riser. Transformation of the PEPT results define (i) the vertical particle movement and population density in a cross sectional area of the riser; (ii) the required transport gas velocity (Utr) to operate in a fully established circulation mode; (iii) the overall particle movement mode (plug flow vs. core/annulus flow); and (iv) the particle slip velocity. Only in a plug flow mode can the particle slip velocity be estimated from the difference of superficial gas velocity and particle terminal velocity. The slip velocity is lower than U - Utr outside the plug flow mode. To operate in plug flow, the superficial gas velocity should exceed Utr by 1 m/s and the solids circulation rate should exceed 200 kg/m2s.",

keywords = "Circulating fluidized bed, Plug flow, Positron tracking, Tracer, Velocities",

author = "{Van De Velden}, M. and J. Baeyens and Seville, {J. P.K.} and X. Fan",

year = "2006",

month = dec,

day = "1",

language = "English",

isbn = "8086059456",

series = "CHISA 2006 - 17th International Congress of Chemical and Process Engineering",

booktitle = "CHISA 2006 - 17th International Congress of Chemical and Process Engineering",

note = "CHISA 2006 - 17th International Congress of Chemical and Process Engineering ; Conference date: 27-08-2006 Through 31-08-2006",

}

Van De Velden, M, Baeyens, J, Seville, JPK & Fan, X 2006, The assessment of the solids flow in the riser of a Circulating Fluidized Bed (CFB) through positron imaging. in CHISA 2006 - 17th International Congress of Chemical and Process Engineering. CHISA 2006 - 17th International Congress of Chemical and Process Engineering, CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, Czech Republic, 27/08/06.

The assessment of the solids flow in the riser of a Circulating Fluidized Bed (CFB) through positron imaging. / Van De Velden, M.; Baeyens, J.; Seville, J. P.K. et al.
CHISA 2006 - 17th International Congress of Chemical and Process Engineering. 2006. (CHISA 2006 - 17th International Congress of Chemical and Process Engineering).

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

TY - GEN

T1 - The assessment of the solids flow in the riser of a Circulating Fluidized Bed (CFB) through positron imaging

AU - Van De Velden, M.

AU - Baeyens, J.

AU - Seville, J. P.K.

AU - Fan, X.

PY - 2006/12/1

Y1 - 2006/12/1

N2 - Circulating Fluidized Beds (CFB) are attracting increasing interest for both gas-solid and gas-catalytic reactions, although operating modes differ completely. To model the reactor, the knowledge of the solids residence time is an important parameter. Previous studies mostly assess operations at moderate values of the solids circulation rates (≤ 100 kg/m2s), whereas gas-catalytic reactions and biomass pyrolysis require completely different operating conditions. Positron Emission Particle Tracking (PEPT) is used to study the movement and population density of particles in the CFB-riser. Transformation of the PEPT results define (i) the vertical particle movement and population density in a cross sectional area of the riser; (ii) the required transport gas velocity (Utr) to operate in a fully established circulation mode; (iii) the overall particle movement mode (plug flow vs. core/annulus flow); and (iv) the particle slip velocity. Only in a plug flow mode can the particle slip velocity be estimated from the difference of superficial gas velocity and particle terminal velocity. The slip velocity is lower than U - Utr outside the plug flow mode. To operate in plug flow, the superficial gas velocity should exceed Utr by 1 m/s and the solids circulation rate should exceed 200 kg/m2s.

AB - Circulating Fluidized Beds (CFB) are attracting increasing interest for both gas-solid and gas-catalytic reactions, although operating modes differ completely. To model the reactor, the knowledge of the solids residence time is an important parameter. Previous studies mostly assess operations at moderate values of the solids circulation rates (≤ 100 kg/m2s), whereas gas-catalytic reactions and biomass pyrolysis require completely different operating conditions. Positron Emission Particle Tracking (PEPT) is used to study the movement and population density of particles in the CFB-riser. Transformation of the PEPT results define (i) the vertical particle movement and population density in a cross sectional area of the riser; (ii) the required transport gas velocity (Utr) to operate in a fully established circulation mode; (iii) the overall particle movement mode (plug flow vs. core/annulus flow); and (iv) the particle slip velocity. Only in a plug flow mode can the particle slip velocity be estimated from the difference of superficial gas velocity and particle terminal velocity. The slip velocity is lower than U - Utr outside the plug flow mode. To operate in plug flow, the superficial gas velocity should exceed Utr by 1 m/s and the solids circulation rate should exceed 200 kg/m2s.

KW - Circulating fluidized bed

KW - Plug flow

KW - Positron tracking

KW - Tracer

KW - Velocities

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M3 - Conference contribution

AN - SCOPUS:34748873425

SN - 8086059456

SN - 9788086059457

T3 - CHISA 2006 - 17th International Congress of Chemical and Process Engineering

BT - CHISA 2006 - 17th International Congress of Chemical and Process Engineering

T2 - CHISA 2006 - 17th International Congress of Chemical and Process Engineering

Y2 - 27 August 2006 through 31 August 2006

ER -

The assessment of the solids flow in the riser of a Circulating Fluidized Bed (CFB) through positron imaging

Abstract

Publication series

Conference

Keywords / Materials (for Non-textual outputs)

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