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Showing 1 to 20 of 66 for “"Holdup"”.
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Gas holdup in a gas-liquid-fiber semi-batch bubble column
… 0.57%, 0.99%, and 2.14% is employed to study gas holdup and flow regime in Rayon and Nylon fiber suspensions. This study determines the effect of superficial gas velocity, fiber type, fiber mass fraction, fiber length, and aeration plate open area ratio on gas holdup and flow regime transition in …
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Hydrodynamics and gas holdup in a cocurrent air-water-fiber bubble column
… the fiber influences on bubble motions and gas holdup in gas-liquid-fiber bubble columns are connected to the unique structure and properties of fiber suspensions;An experimental study is completed to investigate the hydrodynamics and gas holdup in a cocurrent air-water-fiber bubble column. …
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The Effect of Operating Conditions on Gas Holdup and Mixing in Tower Fermenters
… applicable to fermentation processes. Gas holdup was investigated thoroughly under different operating conditions in air-water systems. A number of fermentation media were also used as the liquid phase. It was found that apart from superficial gas velocity which is the governing factor in …
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Effect of Using Enriched Boric Acid as Chemical Shim on B10 Holdup in PWRs
Made available in DSpace on 2017-07-06T18:58:56Z (GMT). No. of bitstreams: 2 Srinivasan_Radhakrishnan_MS.pdf: 40852282 bytes, checksum: c8e9ab48d8cbd3ea51e2cf9d659a4932 (MD5) license.txt: 4813 bytes, checksum: 715c4321821a960fa1a1e91d2ac7ebce (MD5) Previous issue date: 2003
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Pressure drop, liquid holdup and mass transfer in a graphite fibre bed with upward co-current gas-liquid flow
The pressure drop, liquid holdup and overall mass transfer capacity have been studied in a graphite fibre electrode of porosity 0.90and fibre diameter 22 micrometer with cocurrent upward gas-liquid flow. A U-tube mercury manometer was used to measure the pressure drop in a graphite fibre bed 356 mm …
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The prediction of flow patterns, liquid holdup and pressure losses occurring during continuous two-phase flow in horizontal pipelines
… closing" valves by means of which the liquid holdup was measured. Transparent nipples were placed at two points in the two inch line and at three points in the four inch line. Through these nipples the flow patterns were photographed. Pressure taps were located at fourteen points in each line …
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The effects of low aspect ratio and heat exchanging internals on the bubble properties and flow regime in a pilot-plant bubble/slurry bubble column for Fischer-Tropsch synthesis
… and the solids loading, increase the local gas holdup, interfacial area, bubble passage frequency, and decrease the bubble rise velocity, bubble chord length. Meanwhile, the aspect ratio H/D = 4, and 5 provide enough height to established the fully developed flow regime. As a result of the …
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Viscous liquids in bubble columns
… studied in an 8.8cm diameter column, and the gas holdup, resulting from continuous bubbling of gas into this column, was also measured. Agreement between holdup predicted by the equation of Nicklin et al (1962), and experimental data in the present work and that of other workers is good. The …
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Numerical Modeling of Air-Water Flows in Bubble Columns and Airlift Reactors
… heterogeneous flow were shown by examining gas holdup. The flow field predicted using two-dimensional simulations of the airlift reactor showed a regular oscillation of the gas flow due to recirculation from the downcomer and connectors, whereas the bubble column oscillations were random and …
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Mass transfer in bubble column contractors
Gas holdup and overall volumetric mass transfer coefficients in bubble column contactors have been investigated for water and aqueous electrolyte solutions. Two methods were used to obtain experimental data on volumetric mass transfer coefficients: the steady state oxidation technique and a …
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Heat transfer and bubble dynamics in bubble and slurry bubble columns with internals for Fischer-Tropsch synthesis of clean alternative fuels and chemicals
… of the role of local and overall gas holdup, bubble passage frequency, bubble sizes and bubble velocity on the heat transfer characteristics by means of a hybrid measurement technique comprising an advanced four-point optical probe and a fast response heat transfer probe used …
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CFD simulation of the dynamic flow behavior in a bubble column reactor
… to predict the bubbly flow parameter such as gas holdup, contact surface area, air volume fraction, pressure drop, and velocity magnitude to understanding the hydrodynamic flow behaviors. Three types of gas distributor design are tested on the 1.5 m height and 0.15 m diameter bubble column …
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Scaleup and hydrodynamics study of gas-solid spouted beds
… concentration needs to be converted to solids holdup through calibration, for meaningful interpretation of results, a novel calibration method was proposed (which is inexpensive and reliable compared to the current reported methods) and validated in the present study. The reported dimensionless …
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Biological Aerated Filters: Oxygen Transfer and Possible Biological Enhancement
… KLa value. The effects of the media size and gas holdup fractions were also investigated. Stagnant gas holdup did not significantly influence the rate of oxygen transfer. Dynamic gas holdup and the difference between total and stagnant gas holdup were found to increase with an increase in gas …
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Hydrodynamics of trickle bed reactors (TBRS) packed with industrial catalyst using advanced measurement techniques
… improvements in the phase distribution, liquid holdup profile, and catalyst utilization efficiency. In the pilot plant scale reactor, the catalyst shape showed a significant impact on the hydrodynamics, pressure drop, local gas and liquid velocities, and flow regime transition. The currently …
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Investigation of High-density Integrated Solution for AC/DC Conversion of a Distributed Power System
… can be realized. In front-end converter, large holdup time capacitor size is another barrier for power density improvement. To meet the holdup time requirement, bulky holdup time capacitor is normally used to provide energy during holdup time. Holdup time capacitor requirement can be reduced by …
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Process intensification for the iron-catalysed slurry-phase Fischer-Tropsch Reactor System
… stable catalyst performance. Prediction of gas holdup in the reactor is essential to determine the reactor productivity and previous correlations used to predict gas holdup are potentially unreliable for extrapolation to the new proposed conditions. A new approach is adapted, from previous …
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Studies of multiphase distribution and flow in bubble/ slurry bubble columns with /without internals and advanced sustainable construction materials using sophisticated measurement techniques
… and employed to study line-averaged three-phase holdup distribution in a Slurry Bubble Column Reactor (SBCR) using gamma-ray densitometry (GRD) and point optical fiber probe (OFP) techniques. The obtained results indicated that increasing the solids loading increased the solid holdup and …
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Visualizing fluidized beds with X-rays
… of flow conditions. 3-D local, time-averaged gas holdup is calculated from CT data, while dynamic features are captured by X-ray stereography. The results show that CT is most effective on glass bead fluidized beds. Due to high X-ray attenuation, glass bead CT data has higher resolution than …
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Development of Monte Carlo models of a gamma-ray nondestructive assay system for nuclear material control and accountability
… (LANL): electrorefining salt (ER) residues and holdup in gloveboxes. For holdup measurements, accuracy is inherently limited because the exact distribution of material is unknown, which can lead to high uncertainties in reported masses. While the uncertainty in holdup measurements is assumed to …
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