Profiles of particle velocity and solids fraction in a high-density riser

Wei, Fei; Lin, Hongfei; Cheng, Yi; Wang, Zhanwen; Ye, Jin

doi:10.1016/s0032-5910(98)00139-9

Cited by 101 publications

(58 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This means that the particles tend to move away from the central region to the wall region in order to consume less energy. The results show good agreement with earlier results reported by Wei et al [18]. The effects of axial location on solid concentration are shown in Fig.…”

Section: Effects Of Operating Conditions On Solid Concentrationssupporting

confidence: 92%

Experimental Study on Flow Behavior in a Gas‐Solid Fluidized Bed for the Methanol‐to‐Olefins Process

Wang

Sun

et al. 2010

Chem Eng & Technol

View full text Add to dashboard Cite

A cold model experimental system is established to investigate the flow behavior in a gas-solid fluidized bed for the methanol-to-olefins process catalyzed by SAPO-34. The system comprises a gas distributor in a F 300 × 5000 mm acrylic column, double fiber optic probe system and a series of cyclones. The experiments are carried out under conditions of atmospheric pressure and room temperature with different superficial velocities (0.3930-0.7860 m s -1) and different initial bed heights (600-1200 mm). The effects of radial distance, axial distance, superficial gas velocity, and initial bed height on the solid concentration and particle velocity in the bed are discussed. The time-averaged solid concentration and rising particle velocity profiles under different conditions are obtained. The results show that an increase in the value of r/R or initial bed height results in an increase in the solid concentration but a decrease in the rising particle velocity in the dense phase area, while improvement of the superficial gas velocity has a negative influence on the solid concentration but results in an increase in the rising particle velocity.

show abstract

Section: Effects Of Operating Conditions On Solid Concentrationssupporting

confidence: 92%

Experimental Study on Flow Behavior in a Gas‐Solid Fluidized Bed for the Methanol‐to‐Olefins Process

Wang

Sun

et al. 2010

Chem Eng & Technol

View full text Add to dashboard Cite

show abstract

“…The dense region includes a dilute core region and a dense annular region, whereas the dilute region at the upper part of the riser is relatively homogeneous. However, examining the existing experimental data on radial solids holdup distribution (Neri and Gidaspow, 2000;Parssinen and Zhu, 2001;Wei et al, 1998;Wiesendorf and Werther, 2000;Zheng et al, 2001) obtained by optical-fiber probe, capacitance probe, or X-ray densitometer, as shown closely in Figure 2, the solids holdup is far from monotony in its increase with an increase in the radial distance from the center to the wall in the riser. Such a radial solids holdup profile appears to be overlooked by any computational fluid dynamic models (for example, Neri and Gidaspow, 2000;Zheng et al, 2001) in their prediction of the riser hydrodynamics.…”

Section: Objectives Of This Workmentioning

confidence: 98%

“…The cluster velocities, U cluster (Ͼ Ϫ0.3 m/s), obtained by the correlation of Wei et al (1998) from the laser Doppler velocimetry (LDV) measurement, are used in the calculation. At the upper part of the riser, the blob velocity for the gas velocities of 0.97 and 1.46 m/s increases with an increasing solids circulation rate, whereas it increases initially and then levels off for the gas velocity of 1.94 m/s.…”

Section: Blob Behavior In a Cfb Risermentioning

confidence: 99%

ECT studies of the choking phenomenon in a gas–solid circulating fluidized bed

Warsito

Fan

2004

AIChE Journal

View full text Add to dashboard Cite

show abstract

“…Secondly, an increase in the concentration of particles contributes to attenuation of radiation scattered by particles, which makes difficult the operation of the receiving optoelectronic system of LDA. These facts impose significant limitations on the effectiveness of using LDA to study the characteristics of highly concentrated heterogeneous flows [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

“…For example, Evseev et al [9] used LDA with optical-fiber probe, which enabled them to obtain the velocity distributions of sand and polystyrene particles sized 200, 500, and 800 μm with concentration Φ = 0.07. In [5], the use of a special probe made it possible to reduce the distance from the point of entry of laser beams into the medium being investigated to the measurement point. This in turn made possible the measurements of the velocity of solid particles 54 μm in diameter at Φ = 0.21.…”

Section: Introductionmentioning

confidence: 99%