Improved Drying in a Pulsation-Assisted Fluidized Bed

Akhavan, Ali; Ommen, J. Ruud van; Nijenhuis, John; Wang, Xiaosuo; Coppens, Marc‐Olivier; Rhodes, Martin

doi:10.1021/ie800458h

Cited by 57 publications

(43 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this frequency is lower than the frequency after the critical moisture content which suggests the defluidized portion of the bed affects the hydrodynamics. A recent study published on pulse fluidized bed drying of the same pharmaceutical granule as that used in the present study supports this [9]. Pulsation of the fluidization gas improved the mixing in the bottom region of the cylindrical bed and also changed the hydrodynamics.…”

Section: Bubbling Frequencysupporting

confidence: 87%

“…The granule will also exhibit channelling when fluidized [1]. To improve the fluidity of cohesive powders, researchers have proposed several techniques including mechanical vibration [2][3][4][5]7], bed stirring [4,6,7] and gas pulsation [8,9]. However, the pharmaceutical industry does not employ any of these assisting techniques to aid their granule fluidity during drying.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The influence of vessel geometry on fluidized bed dryer hydrodynamics

Wormsbecker¹,

Ommen²,

Nijenhuis³

et al. 2009

Powder Technology

Self Cite

View full text Add to dashboard Cite

Section: Bubbling Frequencysupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

The influence of vessel geometry on fluidized bed dryer hydrodynamics

Wormsbecker¹,

Ommen²,

Nijenhuis³

et al. 2009

Powder Technology

Self Cite

View full text Add to dashboard Cite

“…By pulsing the gas, fluidization is more uniform, and channeling and clumping are prevented. This improves the performance of fluidized bed combustion and drying [81,82]. Periodically perturbing the gas in a fluidized bed can suppress chaos by 'phase locking ' [83], however the periodicity of the bubble pattern is remarkable [79 ].…”

Section: Dynamic Self-organizationmentioning

confidence: 99%

A nature-inspired approach to reactor and catalysis engineering

Coppens

2012

Current Opinion in Chemical Engineering

Self Cite

114

View full text Add to dashboard Cite

Available online at www.sciencedirect.com A nature-inspired approach to Q1 reactor and catalysis engineering Marc-Olivier Coppens Q2Mechanisms used by biology to solve fundamental problems, such as those related to scalability, efficiency and robustness could guide the design of innovative solutions to similar challenges in chemical engineering. Complementing progress in bioinspired chemistry and materials science, we identify three methodologies as the backbone of nature-inspired reactor and catalysis engineering. First, biology often uses hierarchical networks to bridge scales and facilitate transport, leading to broadly scalable solutions that are robust, highly efficient, or both. Second, nano-confinement with carefully balanced forces at multiple scales creates structured environments with superior catalytic performance. Finally, nature employs dynamics to form synergistic and adaptable organizations from simple components. While common in nature, such mechanisms are only sporadically applied technologically in a purposeful manner. Nature-inspired chemical engineering shows great potential to innovate reactor and catalysis engineering, when using a fundamentally rooted approach, adapted to the specific context of chemical engineering processes, rather than mimicry. Introduction Nature-inspired engineering researches the fundamental mechanism underlying a desired property or function in nature, most often in biology, and applies this mechanism in a technological context. In the context of chemical engineering, we call this approach: nature-inspired chemical engineering (NICE) [1].Application of biological mechanisms to a non-physiological context in reaction engineering requires adaptations, because the relevant time scales and available building blocks are different. Also, we are able to manipulate parameters such as temperature and pressure, which are much less tunable in biology. Hence, like in an abstract portrait, essential aspects of the subject are preserved, but not literally, emphasizing those features that serve a desired purpose. Such features underpin the rational design of an artificial structure that uses the same fundamental mechanism as the natural system. The ultimate implementation is assisted by theory and experimentation. NICE aims to innovate, guided by nature, but it does not mimic nature, and should be applied in the right context.Emphasizing reactor and catalysis engineering, we illustrate how mechanisms used in biology to satisfy complicated requirements, essential to life, are adapted to guide innovative solutions to similar challenges in chemical engineering. These mechanisms include: (1) use of optimized, hierarchical networks to bridge scales, minimize transport limitations, and realize efficient, scalable solutions; (2) careful balancing of forces at one or more scales to achieve superior performance, for example, in terms of yield and selectivity; (3) emergence of complex functions from simple components, using dynamics as an organizing mechanism. Figure 1 presents an overview....

show abstract

“…A mathematical model was proposed to offer approximate predictions of the natural frequency of the fluidized bed, around which the pulsation was most effective. DEM simulation by Wang and Rhodes [19,32] confirmed that a frequency of 3-10 Hz would be most effective in ameliorating gas-solid interaction. Periodically formed horizontal gas channels were spotted where they quickly gave rise to regular bubbles, which moved up to the surface of the bubbling bed.…”

Section: Introductionmentioning

confidence: 97%

“…Besides relying on improving the design of gas distributors and operated at high flow rates, pulsation and vibration have been commonly used in granulation, coating and drying of sticky powders and irregularly shaped agricultural products [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. Pulsed fluidized beds, in which the gas flow rate oscillates periodically with time, have been proven effective in transforming random and chaotic bubble behavior into regular and ordered patterns, improving the fluidization quality of coarse particles greatly [28].…”

Section: Introductionmentioning

confidence: 99%

Fluidization and drying of biomass particles in a vibrating fluidized bed with pulsed gas flow

Jia

Cathary

Peng

et al. 2015

Fuel Processing Technology

View full text Add to dashboard Cite

a b s t r a c tFluidization of biomass particles in the absence of inert bed materials has been tested in a pulsed fluidized bed with vibration, with the pulsation frequency ranging from 0.33 to 6.67 Hz. Intermittent fluidization at 0.33 Hz and apparently 'normal' fluidization at 6.67 Hz with regular bubble patterns were observed. Pulsation has proven to be effective in overcoming the bridging of irregular biomass particles induced by strong inter-particle forces. The vibration is only effective when the pulsation is inadequate, either at too low a frequency or too low in amplitude. Drying of biomass has been carried out to quantify the effectiveness of gas pulsation for fluidized bed dryers and torrefiers in terms of gas-solid contact efficiency and heat and mass transfer rates. The effects of gas flow rate, bed temperature, pulsation frequency and vibration intensity on drying performance have been systematically investigated. While higher temperature and gas flow rate are favored in drying, there exists an optimal range of pulsation frequency between 0.75 Hz and 1.5 Hz where gas-solid contact is enhanced in both the constant rate drying and falling rate drying periods.

show abstract

Improved Drying in a Pulsation-Assisted Fluidized Bed

Cited by 57 publications

References 22 publications

The influence of vessel geometry on fluidized bed dryer hydrodynamics

The influence of vessel geometry on fluidized bed dryer hydrodynamics

A nature-inspired approach to reactor and catalysis engineering

Fluidization and drying of biomass particles in a vibrating fluidized bed with pulsed gas flow

Contact Info

Product

Resources

About