The influence of granular flow rate on the performance of a moving bed granular filter

El-Hedok, Ibrahim Adnan; Whitmer, Lysle E.; Brown, Robert C.

doi:10.1016/j.powtec.2011.07.037

Cited by 56 publications

(32 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(25) with the experimental data taken on a granular aerosol filter [5] , which used a packed bed of pea gravels to collect char particles laden in air stream. In this experiment the bulk critical specific deposit was determined by inspecting the history of filter collection efficiency and the value was [5] . The amount of deposit was obtained by sifting collected char particles from the pea gravels.…”

Section: Solutions and Discussionmentioning

confidence: 99%

“…In slow sand filters, which are commonly used for water purification, the pressure drop usually remains a constant for a considerable duration as deposits accumulate, then rises exponentially with the volume of filtrate [1] [2][3] [4] . On the contrary in granular aerosol filters the pressure drop typically increases linearly with the amount of deposit from the very beginning of the filtration process [5] [6] . In addition, experiments demonstrated that in slow sand filters the pressure drop increase is concentrated to a thin layer (Schmutzdecke) at the top of the filter bed where the raw water flows into the bed, below which the filter medium remains hydraulically clean, i.e.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A statistical model of pressure drop increase with deposition in granular filters

Qin¹,

Pletcher²

2015

Advanced Powder Technology

View full text Add to dashboard Cite

As deposits accumulate in a granular filter, pressure drop across the filter bed required to maintain a constant fluid flow rate may increase. Two pressure drop increase patterns had been observed. In slow sand filters pressure drop remains unchanged for a certain period of time then increases exponentially with the volume of filtrate; in granular aerosol filters pressure drop increases linearly with the amount of deposits from the beginning of the filtration process. New concepts of homogeneous and heterogeneous depositions were introduced in this paper. A statistical model based on these new concepts was developed. This non-linear model was able to reproduce both observed pressure drop increase patterns, including the linear one. Excellent agreements between the present model and experimental measurements were obtained. It was concluded that the two pressure drop increase patterns were indeed caused by different deposit distributions rather than different pressure drop increase mechanisms.

show abstract

Section: Solutions and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A statistical model of pressure drop increase with deposition in granular filters

Qin¹,

Pletcher²

2015

Advanced Powder Technology

View full text Add to dashboard Cite

show abstract

“…12,13 Moreover, in the currently developed technologies of other rapid coal pyrolysis, 14 same problems are also common: dust is difficult to separate from the gas/tar, high dust content in tar, etc. Dust removal of coal pyrolysis volatiles has become one of the bottlenecks in the development of the fast pyrolysis process.…”

Section: -10mentioning

confidence: 99%

Studies of granular bed filter for dust removal in the process of coal pyrolysis by solid heat carrier

Zhang

Liang

et al. 2017

RSC Adv.

View full text Add to dashboard Cite

Aiming at the optimization of the dust removal process in the poly-generation system of circulating fluidized bed (CFB) combustion/coal pyrolysis, a granular bed filter (GBF) is applied to the coal pyrolysis by solid heat carrier. By carrying out lab-scale experiments with a moving-bed pyrolyzer, the GBF model proposed by C. Tien et al. was used to describe the dust removal process of the dust-contained volatiles which has high temperature and high viscosity. The model applicability for real pyrolysis volatiles was verified. The results show that, the particle size distribution of the dust uncollected by the GBF is relatively concentrated. The majority particle size of uncollected dust is less than 20 mm, the mass fraction is $80%. The GBF is in a state of unsteady operation in the process of dust filtration. With the increase of operating time, the dust is gradually deposited in the GBF, then resulting in an increase of bed pressure drop. In the examined range, the calculational value of GBF efficiency is slightly lower than the experimental value. On the one hand, the filter media particles have a certain specific surface area, so that part of the dust-contained tar can be adsorbed on the filter media surface to achieve a better interception effect. On the other hand, the dust particle deposited in the GBF also plays an important role in dust capture. The C. Tien model results of the initial filtration efficiency can be used as the selection reference of the medium species and the physical properties of the GBF. The higher filter height, slower superficial gas velocity, and smaller size of medium are conducive to decrease the dust content in the pyrolysis products. This study can provide basic data for the dust removal process in the poly-generation system of CFB combustion/coal pyrolysis.

show abstract

“…In moving beds, the collectors move continuously at low velocity, allowing their regeneration during filtration. These processes were the subject of several studies, which showed that they can achieve a high mass efficiency when the filtration superficial velocity and the collector mass flow are chosen in a certain range of values . However, operators should keep in mind that a decrease in efficiency occurs when the moving bed passes from a “fixed bed” mode to a “moving bed” one .…”

Section: Introductionmentioning

confidence: 99%

Trickle bed applied to the post‐treatment of blast furnace dust

Thieffry

Charvet

Bardin‐Monnier

et al. 2017

Asia-Pacific J Chem Eng

View full text Add to dashboard Cite

This study aims to develop an original filtration device based on a trickle bed technology which permits to treat high gas flow rates while maintaining a constant pressure drop by re-entraining continuously the particles trapped on collectors, thanks to a water film flow. Good results have been obtained for an air flow rate of 20 m 3 /hr, a liquid flow rate of 12 L/min and using glass beads of 5-mm diameter as collectors. Experimental results showed a good mass efficiency (89%) and a pressure drop which stabilizes under clogging unlike that of a granular bed which increases during the clogging. The experiments certifying a stable pressure drop during a few tens of hours let us suppose that these tendencies should be extrapolated to much larger times.

show abstract

The influence of granular flow rate on the performance of a moving bed granular filter

Cited by 56 publications

References 6 publications

A statistical model of pressure drop increase with deposition in granular filters

A statistical model of pressure drop increase with deposition in granular filters

Studies of granular bed filter for dust removal in the process of coal pyrolysis by solid heat carrier

Trickle bed applied to the post‐treatment of blast furnace dust

Contact Info

Product

Resources

About