Granular Flow of Corn Stover Particles in a Helical Ribbon Stirred Tank

2017 ◽  
Vol 15 (3) ◽  
Author(s):  
Juan Huang ◽  
Gance Dai
Keyword(s):  
Power Consumption ◽  
Corn Stover ◽  
Rotational Speed ◽  
Solid Phase ◽  
Flow Characteristics ◽  
Stirred Tank ◽  
Core Material ◽  
Granular Bed ◽  
Helical Ribbon ◽  
High Solids Loading

Abstract The flow characteristics and power consumption of corn stover particles in a helical ribbon stirred tank was investigated in the context of simultaneous saccharification and fermentation of corn stover at high solids loading. It was found that the particles in the tank can be divided into conveyed material and core material according to their flow characteristics. The flow of the former materials was frictional regime and the latter was intermediate flow; the conveyed material avalanched into the core at the top of granular bed. The granular bed dilated when the impeller was rotating, which was beneficial for the entrance of liquid enzyme into the solid phase and for the successful proceeding of the saccharification of the corn stover. The power of granular mixing was linearly proportional to the impeller rotational speed due to the discrete characteristic of the particles and flow dynamics of the conveyed material. The ratio of power consumption to the impeller rotational speed (P/N) was linear proportional to loading ratio and the dimensionless torque (M/mgR) was 0.48. The power consumption increased first and then decreased as the corn stover particles evolved from granular/wet granular to paste/slurry. The maximum power consumption was at 83 % (w/w) moisture content.

Laminar Mixing Performances of a Stirred Tank Equipped with Helical Ribbon Agitator Subjected to Steady and Unsteady Rotational Speed

2002 ◽  
Vol 80 (4) ◽  
pp. 335-344 ◽  
Author(s):  
J.-Y. Dieulot ◽  
G. Delaplace ◽  
R. Guerin ◽  
J.-P. Brienne ◽  
J.-C. Leuliet
Keyword(s):  
Rotational Speed ◽  
Stirred Tank ◽  
Helical Ribbon ◽  
Laminar Mixing

Hydrodynamics in a vessel stirred by simple and double helical ribbon impellers

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Houari Ameur ◽  
Mohamed Bouzit ◽  
Abdellah Ghenaim
Keyword(s):  
Power Consumption ◽  
Finite Volume Method ◽  
Satisfactory Agreement ◽  
Rotational Speed ◽  
Flat Bottom ◽  
Helical Ribbon ◽  
Shear Thinning Fluids ◽  
Tank Bottom ◽  
Volume Method ◽  
Fluid Rheology

AbstractThe present paper treats the agitation of shear thinning fluids in a cylindrical unbaffled vessel with a flat-bottom. Two kinds of impellers have been used: simple and double helical ribbons. This work is achieved with the help of CFD package (CFX-12.0), which is based on the finite volume method to solve the continuity and momentum equations. The effect of impeller rotational speed, fluid rheology, impeller size, impeller clearance from the tank bottom on the flow fields and power consumption have been investigated. Finally, a comparison between the two impellers is made. It was found that the best performance is obtained with double helical ribbon impeller placed at the middle of the tank, with moderate blade size and operating at Re g > 20. Our results have been compared with those of other literatures and a satisfactory agreement is observed.

scholarly journals Quantitative and Qualitative Analysis of Some Inorganic Compounds by Raman Spectroscopy

1994 ◽  
Vol 48 (7) ◽  
pp. 875-883 ◽  
Author(s):  
Daniel R. Lombardi ◽  
Chao Wang ◽  
Bin Sun ◽  
Augustus W. Fountain ◽  
Thomas J. Vickers ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Raman Spectroscopy ◽  
Qualitative Analysis ◽  
Raman Spectra ◽  
Solid Phase ◽  
Inorganic Compounds ◽  
Core Material ◽  
Storage Tanks ◽  
Hanford Site ◽  
Sampling Probe

Raman spectra have been measured for a number of nitrates, nitrites, sulfates, ferrocyanides, and ferricyanides, both in the solid phase and in aqueous solution. Accurate locations of peak maxima are given. Limits of detection for some of the compounds are given for solutions and for solid mixtures in NaNO3. Preliminary measurements have been made on core material recovered from the storage tanks on the Hanford site in Richland, Washington. Representative spectra are presented, showing that it is possible to observe responses of individual components from measurements made directly on untreated cores, with the use of a fiberoptic sampling probe.

scholarly journals Toward Biochemical Conversion of Lignocellulose On-Farm: Pretreatment and Hydrolysis of Corn Stover in Situ

2017 ◽  
Vol 60 (4) ◽  
pp. 1025-1033
Author(s):  
Alicia A. Modenbach ◽  
Sue E. Nokes ◽  
Michael D. Montross ◽  
Barbara L. Knutson
Keyword(s):  
Enzymatic Hydrolysis ◽  
Corn Stover ◽  
Conversion Efficiency ◽  
High Solids ◽  
Cellulose Conversion ◽  
Biochemical Conversion ◽  
High Solids Loading ◽  
Combined Pretreatment ◽  
Pretreatment Conditions ◽  
On Farm

Abstract. High-solids lignocellulosic pretreatment using NaOH followed by high-solids enzymatic hydrolysis was evaluated for an on-farm biochemical conversion process. Increasing the solids loadings for these processes has the potential for increasing glucose concentrations and downstream ethanol production; however, sequential processing at high-solids loading similar to an on-farm cellulose conversion system has not been studied. This research quantified the effects of high-solids pretreatment with NaOH and subsequent high-solids enzymatic hydrolysis on cellulose conversion. As expected, conversion efficiency was reduced; however, the highest glucose concentration (40.2 g L-1), and therefore the highest potential ethanol concentration, resulted from the high-solids combined pretreatment and hydrolysis. Increasing the enzyme dosage improved cellulose conversion from 9.6% to 36.8% when high-solids loadings were used in both unit operations; however, increasing NaOH loading and pretreatment time did not increase the conversion efficiency. The enzyme-to-substrate ratio had a larger impact on cellulose conversion than the NaOH pretreatment conditions studied, resulting in recommendations for an on-farm bioconversion system. Keywords: Corn stover, Enzymatic hydrolysis, Enzyme loading, High solids, Low solids, Sodium hydroxide.

Modeling evaluation on solid-liquid mixing characteristics in a dislocated guide impeller stirred tank

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Deyin Gu ◽  
Fenghui Zhao ◽  
Xingmin Wang ◽  
Zuohua Liu
Keyword(s):  
Power Consumption ◽  
Solid Particle ◽  
Particle Diameter ◽  
Solid Particles ◽  
Stirred Tank ◽  
Mixing Process ◽  
Solid Holdup ◽  
Aperture Ratio ◽  
Liquid Mixing ◽  
Solid Liquid

Abstract The solid-liquid mixing characteristics in a stirred tank with pitched blade impellers, dislocated impellers, and dislocated guide impellers were investigated through using CFD simulation. The effects of impeller speed, impeller type, aperture ratio, aperture length, solid particle diameter and initial solid holdup on the homogeneity degree in the solid-liquid mixing process were investigated. As expected, the solid particle suspension quality was increased with an increase in impeller speed. The dislocated impeller could reduce the accumulation of solid particles and improve the cloud height compared with pitched blade impeller under the same power consumption. The dislocated guide impeller could enhance the solid particles suspension quality on the basis of dislocated impeller, and the optimum aperture ratio and aperture length of dislocated guide impeller were 12.25% and 7 mm, respectively, in the solid-liquid mixing process. Smaller solid particle diameter and lower initial solid holdup led to higher homogeneity degree of solid-liquid mixing system. The dislocated guide impeller could increase solid particle integrated velocity and enhance turbulent intensity of solid-liquid two-phase compared with pitched blade impeller and dislocated impeller under the same power consumption.

Serial completely stirred tank reactors for improving biogas production and substance degradation during anaerobic digestion of corn stover

2017 ◽  
Vol 235 ◽  
pp. 380-388 ◽  
Author(s):  
YuQian Li ◽  
ChunMei Liu ◽  
Akiber Chufo Wachemo ◽  
HaiRong Yuan ◽  
DeXun Zou ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Corn Stover ◽  
Biogas Production ◽  
Stirred Tank ◽  
Stirred Tank Reactors

Study of Flow Characteristics of Oil and Water in the Process of Stirring

2013 ◽  
Vol 353-356 ◽  
pp. 3190-3193
Author(s):  
Zong Rui Hao ◽  
Juan Xu ◽  
Hai Yan Bie ◽  
Zhong Hai Zhou
Keyword(s):  
Flow Field ◽  
Flow Pattern ◽  
Cross Section ◽  
Radial Flow ◽  
Flow Characteristics ◽  
Stirred Tank ◽  
Turbulent Model ◽  
Vof Model ◽  
Circular Flows ◽  
Oil Water

To study the flow pattern in the process of oil-water stirring in three paddle stirring tank, RNG k-ε turbulent model and VOF model are adopted to simulate the flow field at different time in the stirred tank with the baffle. The results showed that, in the stirring process, inverted cone manifold was formed in the center of the stirring shaft. The stratified area was formed in the baffle and gradually transported to the bottom of the tank. The two circular flows were formed among three groups of blades. And the axially acting of the fluid was strong, which made homogeneous stirring in the stirred tank. At the same time the radial flow of the cross-section inside the tank increased because of the baffle.

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