Fluctuations and waves in fluidized bed systems: The influence of the air-supply system

Sasic, Srdjan; Leckner, Bo G; Johnsson, Filip

doi:10.1016/j.powtec.2005.03.012

Cited by 39 publications

(28 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the distributor and the bed pressure drops during experiments were of the same order. Under similar conditions Johnsson et al [23] and Sasic et al [24] showed that bed operates under the multiple bubble regime and the bed and the air-supply system are independent.…”

Section: Experimental Set-upmentioning

confidence: 94%

“…In order to avoid influences of the air-supply system in the bubble eruption pattern, the distributor pressure drop must be high enough to assure that the bed and the air-supply system are uncoupled [23,24]. In this way, the distributor used during experiments was a perforated plate with 110 holes 1 mm in diameter with a 1 cm The gas pressure drop through the bed is P bed 4000 Pa and the superficial gas velocity during experiments was around 1 m/s.…”

Section: Experimental Set-upmentioning

confidence: 99%

See 1 more Smart Citation

Experimental observations on the different mechanisms for solid ejection in gas-fluidized beds

Almendros-Ibáñez

Sánchez-Delgado

Sobrino

et al. 2009

Chemical Engineering and Processing: Process Intensification

View full text Add to dashboard Cite

a b s t r a c tThis work presents an experimental study of the ejection velocity for different mechanisms of solid ejection in fluidized beds. The experiments were carried out in a 2D fluidized bed, where the bubble eruptions were recorded with a frequency of 250 frames per second using a high speed video camera with a resolution of 1.3 Megapixels.The results show that in isolated bubble eruption, the dome velocity is significantly reduced by the effect of a group of raining particles in the form of stalactites within the bubble. Higher velocities are observed when bubble coalescence takes place. If bubbles coalesce before the leading bubble breaks, the momentum of the trailing bubble together with the increase in the throughflow accelerate the dome of the leading bubble. In contrast, when coalescence occurs after the breakage of the leading bubble, the wake of the trailing bubble is projected into the freeboard with a very high velocity (wake spike mechanism). The last observed mechanism, the jet spike mechanism, occurs when a stream of bubbles reaches the bed surface following the path opened by the previous bubbles. A cloud of particles moving upward is observed, although their velocities are not as high as in the wake spike mechanism due to the interchange of momentum during the collisions with other particles.Finally, an explanation for some of the patterns of gas release from erupting bubbles recently observed by Hartung et al.

show abstract

Section: Experimental Set-upmentioning

confidence: 94%

Section: Experimental Set-upmentioning

confidence: 99%

Experimental observations on the different mechanisms for solid ejection in gas-fluidized beds

Almendros-Ibáñez

Sánchez-Delgado

Sobrino

et al. 2009

Chemical Engineering and Processing: Process Intensification

View full text Add to dashboard Cite

show abstract

“…Pressure drop through this element (ΔP dist = 60440·u g 2 at 850 ºC) was high enough to ensure that the bed and the air supply system were not coupled [36].…”

Section: Methodsmentioning

confidence: 99%

Defluidization and agglomeration of a fluidized bed reactor during Cynara cardunculus L. gasification using sepiolite as a bed material

Serrano

Sánchez-Delgado

Sobrino

et al. 2015

Fuel Processing Technology

View full text Add to dashboard Cite

This work studies the defluidization time and the agglomerates generation in a Bubbling Fluidized Bed (BFB) reactor during Cynara Cardunculus L. gasification using, separately, two different bed materials, silica sand and sepiolite (Mg 8 Si 12 O 30 (OH) 4 (OH 2 ) 4 8H 2 ). The high adsorption capacity and the elemental composition of the sepiolite make it suitable as an alternative bed material in order to reduce agglomeration. Experiments were performed on a stainless steel lab-scale BFB reactor operating with air as gasifying agent at different air excess ratios (u/u mf ). A quartz reactor was alternatively used for the visualization of bed material and biomass during gasification, allowing to observe the agglomerate formation process. Pressure signals were analyzed both in time and frequency domain to determine the defluidization time.Furthermore, the shape and size of the bed material after the experiments were evaluated.Higher defluidization times in the case of sepiolite were measured. Particle sizes were affected by the type of bed material and the air excess and agglomerates of different shapes were formed for sepiolite and silica sand.

show abstract

“…In order to intensify the transfer processes in apparatuses with a fluidized bed in works [8][9][10][11] proposed applying the pulsating feed of coolant during working with heat-resistant materials. In particular, [8] the pulsating mode of coolant feeding to a fluidized bed is performed by using a mechanical pulsator.…”

Section: Analysis Of a Literaturementioning

confidence: 99%

Non-uniform fluidization in auto-oscillating mode

Kornienko¹,

Haidai²

2017

Ukr. food j.

View full text Add to dashboard Cite

show abstract

Fluctuations and waves in fluidized bed systems: The influence of the air-supply system

Cited by 39 publications

References 21 publications

Experimental observations on the different mechanisms for solid ejection in gas-fluidized beds

Experimental observations on the different mechanisms for solid ejection in gas-fluidized beds

Defluidization and agglomeration of a fluidized bed reactor during Cynara cardunculus L. gasification using sepiolite as a bed material

Non-uniform fluidization in auto-oscillating mode

Contact Info

Product

Resources

About