• KSBB Journal
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• v.4 no.2
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• pp.78-86
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• 1989

The effective saccharification of cellulosic biomass to glucose is the most critical step for the conversion of renwable biomass to alternative liquid fuel. The enzymatic hydrolysis of biomass can be significantly enhanced provide the attrition milling media is added during hydrolysis. The enhancing mechanism of hydrolysis reaction in an agitated bead system was investigated. An attrition-reactor (bioattritor) which installed specially designed torque measuring apparatus was developed, and the potimal saccharification conditions of bioattritor were determined. The relationship between the power consumption required for agitation of attrition-milling media and enhanced extent of hydrolysis of biomass was compared to evaluatic economic feasibility of the process.

• The KSFM Journal of Fluid Machinery
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• v.17 no.6
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• pp.29-37
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• 2014

Non-Newtonian fluid mechanics takes charge of an important role in the oil industries. Especially in the oil well drilling process, the drilling fluid such as mud keeps the drill bit cool and clean during drilling, with suspending drill cuttings and lubricating a drill bit. The purpose of this study is to examine the effect of fluid mud rheological properties to predict different characteristics of non-Newtonian fluid in the mud mixing tank on offshore drilling platforms. In this paper, ANSYS fluent package was used for the simulation to solve the hydrodynamic force and to evaluate mud mixing time. Prediction of the power consumption and the pumping effectiveness has been presented with different operating fluid models as Newtonian and non-Newtonian fluid. The comparison between Newtonain mud model and non-Newtonian mud model is confirmed by the CFD simulation method of drilling mud mixing tank. The results present useful information for the design of the drilling mud mixing tanks and provide some guidance on the use of CFD tool for such non-Newtonian fluid flow.

• Korean Chemical Engineering Research
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• v.53 no.2
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• pp.174-180
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• 2015

The flow pattern and the solid-liquid mass transfer coefficient in figure-eight shaking vessels were observed by experimental method. The flow patterns, mixing time, power consumption and mass transfer coefficient in the figureeight shaking vessels changed irregularly with increase in the shaking frequency. Any frequency, even in the Fr = 0.095 or more became clear experimentally. The region of the optimum operating condition of the figure-eight shaking was larger than that of the reciprocal shaking. The solid-liquid mass transfer coefficient was correlated with the same correlation as that of the rotary shaking vessel of existing. The gas-liquid mass transfer coefficient of the figure-eight shaking vessel was also correlated with the same type of correlation as that of the rotary shaking vessel of existing.

• Journal of Aerospace System Engineering
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• v.13 no.1
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• pp.1-10
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• 2019

The flow characteristics in a stirred tank are very useful in a wide variety of industrial applications. Generally, the flow pattern, power consumption and mixing time in stirred vessels depend not only on the design of the impeller, but also on the tanks' geometry and internal structure. In this study, the analysis of an unstable and unsteady complicated flow characteristics generated by the interaction between the baffle shape and impeller were performed using the ANSYS FLUENT LES Turbulence Model. The study compared the predictions of CFD with the interaction between two types of rotating impellers (axial and radial flows) and the shapes of three baffles. The results of the comparison verified that the design model showed a relatively efficient trend in the mixing flow fields and characteristics around the impeller and baffles during agitation.