Characterization of the upward motion of an object immersed in a bubbling fluidized bed of fine particles

Monitoring the fluidization quality represents an operating challenge for many processes in which a liquid is sprayed into a gas-fluidized bed, such as fluid coking, fluid catalytic cracking, gas-phase polymerization, agglomeration and drying. Although the presence of liquid will generally have an adverse effect on fluidization, there are often strong incentives in operating with high liquid loadings. For the fluid coking process, for example, operating at lower reactor temperature increases yield and reduces emissions but increases the bed wetness, which may lead to local zones of poor mixing, local defluidization and a reduction in fluidization quality, compromising the reactor performance and stability. The objective of this study is to develop reliable methods to quantify the effects of liquids on fluidized beds.This study examined several methods to evaluate the fluidization quality. Each method was tested in a 3 m tall column, 0.3 m in diameter. Bed wetness was achieved with an atomized spray of various liquids, spanning a wide range of liquid properties.The introduction of liquid in a fluidized bed may result in the formation of wet agglomerates that settle at the bottom of the bed. The liquid may also spread on the particles, increasing their cohesivity and reducing the bed fluidity.Several experimental methods were developed to characterize the effect of liquids on fluidization. Some methods such as the falling ball velocity or the detection of micro-agglomeration from the entrainment of fine particles, are unaffected by agglomerates and detect only the change in bed fluidity. Other methods, such as deaeration or the determination of bubble size from the TDH, are affected by agglomerate formation and changes in bed fluidity.

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CHARACTERIZATION OF AN EXPERIMENTAL FACILITY FOR BUBBLING FLUIDIZED BED COMBUSTOR

JES. Journal of Engineering Sciences ◽

10.21608/jesaun.2018.114985 ◽

2018 ◽

Vol 46 (5) ◽

pp. 556-573

Author(s):

Hamdy M. Shafey ◽

Walid J. Al-Nahari ◽

Emad H. El-Zohri ◽

Aliaa O. Abbas

Keyword(s):

Fluidized Bed ◽

Experimental Facility ◽

Bubbling Fluidized Bed ◽

Fluidized Bed Combustor

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Physical and Chemical Characterization of Aerosol Particles Formed during the Thermochemical Conversion of Wood Pellets Using a Bubbling Fluidized Bed Gasifier

Energy & Fuels ◽

10.1021/ef7002552 ◽

2007 ◽

Vol 21 (6) ◽

pp. 3660-3667 ◽

Cited By ~ 25

Author(s):

Eva Gustafsson ◽

Michael Strand ◽

Mehri Sanati

Keyword(s):

Fluidized Bed ◽

Aerosol Particles ◽

Chemical Characterization ◽

Thermochemical Conversion ◽

Wood Pellets ◽

Physical And Chemical Characterization ◽

Bubbling Fluidized Bed ◽

Fluidized Bed Gasifier ◽

Physical And Chemical

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Experimental Study of Absorbent Hygiene Product devolatilization in a bubbling fluidized bed

10.20944/preprints202104.0388.v1 ◽

2021 ◽

Author(s):

Barbara Malsegna ◽

Andrea Di Giuliano ◽

Katia Gallucci

Keyword(s):

Experimental Study ◽

Fluidized Bed ◽

Chemical Characterization ◽

Laboratory Scale ◽

Pure Nitrogen ◽

Free Basis ◽

Ultimate Analysis ◽

Bubbling Fluidized Bed ◽

Proximate And Ultimate Analysis

This paper aims to investigate the usage of waste from Absorbent Hygienic Products (AHP) as a fuel for gasification or pyrolysis, two attractive routes to obtain valuable products and dispose of this kind of waste. The study experimentally investigated the devolatilization of coarsely shred-ded materials from diapers, in a laboratory-scale bubbling fluidized bed made of sand, as a rep-resentative preparatory step of above-mentioned thermochemical conversions. Two versions of shredded materials were considered: as-manufactured diapers (AHPam, as a reference), and the cellulosic fraction of sterilized used diapers (AHPus). Results were presented, obtained from physic-chemical characterization of AHPam and AHPus (TGA, CHNS/O, proximate and ultimate analysis, XRF, ICP-AES, SEM-EDS) and their devolatilizations at 500-600-700-800°C, under two different atmospheres (air plus nitrogen, or pure nitrogen as a reference). Generally, temperature had most influenced syngas composition, with better performances under pure nitrogen. At 700-800 °C under pure nitrogen, the highest syngas quality and yield were obtained. For AHPam and AHPus, respectively: (i) H2 richness equaled 29.5 vol% and 23.7 vol%, while hydrocarbons poorness equaled 14.8 vol% and 7.4 vol% on dry, dilution-free basis; (ii) 53.7 Nl 100 gfuel-1 and 46.0 Nl 100 gfuel-1 were produced. Overall, AHP emerged as an interesting fuel for thermochemical conversions.

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Characterization of pressure fluctuation signals in an acoustic bubbling fluidized bed

Journal of the Taiwan Institute of Chemical Engineers ◽

10.1016/j.jtice.2011.05.001 ◽

2011 ◽

Vol 42 (6) ◽

pp. 929-936 ◽

Cited By ~ 11

Author(s):

Chongdian Si ◽

Jing Zhou ◽

Qingjie Guo

Keyword(s):

Fluidized Bed ◽

Pressure Fluctuation ◽

Bubbling Fluidized Bed

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Fluidization Behavior of Alumina Nano-Particles

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.110-116.1833 ◽

2011 ◽

Vol 110-116 ◽

pp. 1833-1840 ◽

Cited By ~ 1

Author(s):

Tanuja Vaidya

Keyword(s):

Heat Transfer ◽

Fluidized Bed ◽

Fine Particles ◽

Size Range ◽

Nano Particles ◽

Alumina Powder ◽

Particle Size Range ◽

Bubbling Fluidized Bed ◽

Set Up ◽

Scanning Electron

The experimental study is conducted to determine the fluidization behavior and heat transfer variations across the bed in the bubbling fluidized bed having very fine particles. The powder is analyzed using scanning electron microscope (SEM) and Mastersizer analyzer. The bubbling fluidized bed set-up was designed, developed and installed for the hydrodynamic and heat transfer studies. From the experiments, it is found that the alumina powder with particle size range of 200nm to 10μm has agglomerate bubbling fluidized bed (ABF).

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