Fouling Evaluation for Ultrafiltration of Protein-based Washwater: A Resistance-in-series Model Approach

2015 ◽  
Vol 74 (7) ◽  
Author(s):  
Diyana Kamarudin ◽  
Nora’aini Ali ◽  
Mahirah Ismail ◽  
Norasikin Othman
Keyword(s):  
Cross Flow ◽  
Operating Conditions ◽  
Wash Water ◽  
Separation System ◽  
Pvdf Membrane ◽  
Cake Formation ◽  
Model Protein ◽  
In Series ◽  
Cross Flow Velocity ◽  
Kinetics Of

A comprehensive understanding of fouling mechanisms throughout the separation system process is crucial in designing a desired bio-separation system. In this research, we have adopted a resistance-in-series model to determine magnitude of four major resistances that govern in fouling mechanisms namely membrane hydraulic (Rm), adsorption (Rad), pore plugging(Rpp) and cake formation (Rc) resistances. The experiments were conducted using a tubular ultrafiltration Polyvinylidene (PVDF) membrane with surimi wash water as model protein-solution. Two main operating parameters of trans-membrane pressure (TMP) and cross-flow velocity (CFV) were chosen to study the effects of operating conditions towards fouling mechanisms evaluated using resistance-in-series model. The resistance magnitudes were in the following sequence: Rpp >Rad > Rc > Rm. The growth kinetics of each phase on resistances and the kinetic constants represent the extent of flux drop were quantified. Permeate obtained from the filtration process produced the clarified washwater with satisfactory quality physically and physico-chemically based water on national water quality standards.

Cake Formation in Cross-Flow Microfiltration Systems

1992 ◽  
Vol 25 (10) ◽  
pp. 149-162 ◽  
Author(s):  
V. L. Pillay ◽  
C. A. Buckley
Keyword(s):  
Cross Flow ◽  
Operating Conditions ◽  
Waste Waters ◽  
Domestic Waste ◽  
Time Curve ◽  
Good Correspondence ◽  
Operating Variables ◽  
Start Up ◽  
Turbulent Flow Regime ◽  
Cake Formation

Cross-flow microfiltration (CFMF) has potentially wide application in the processing of industrial and domestic waste waters. Optimum design and operation of CFMF systems necessitates a knowledge of the characteristic system behaviour, and an understanding of the mechanisms governing this behaviour. This paper is a contribution towards the elucidation and understanding of the behaviour of a woven fibre CFMF operated in the turbulent flow regime. The characteristic flux-time curve and effects of operating variables on flux are presented for a limestone suspension cross-flow filtered in a 25 mm woven fibre tube. The phenomena contributing to the shape of the flux-time curve are discussed. A model of the mechanisms governing cake growth and limit is presented. Predicted steady-state fluxes show a notably good correspondence with experimentally measured values. It is also found that the flux may not be uniquely defined by the operating conditions, but may also be a function of the operating path taken to reach the operating point. This is of significance in the start-up and operation of CFMF units.

scholarly journals The concentrating of alizarin using a reverse osmosis process

2005 ◽  
Vol 70 (1) ◽  
pp. 107-114 ◽  
Author(s):  
S.S. Madaeni ◽  
H. Daneshvar
Keyword(s):  
Flow Velocity ◽  
Reverse Osmosis ◽  
Cross Flow ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Transmembrane Pressure ◽  
Reverse Osmosis Membrane ◽  
Cross Flow Velocity ◽  
Membrane Technologies ◽  
Madder Root

Membrane technologies in general and reverse osmosis in particular have been employed for the concentrating of solutions. In this study, the concentrating of a heat sensitive alizarin extracted from madder root was realized using an FT30 reverse osmosis membrane. The effects of cross flow velocity, transmembrane pressure and pH on the flux and rejection were studied. Increasing the transmembrane pressure increased the flux while the rejection was constant. At pH 7-8, the highest flux was achieved. This study showed that reverse osmosis is the process of choice for the concentrating of alizarin solutions. The optimum operating conditions were 1.0 m/s cross flow velocity, 16 bars transmembrane pressure and pH 7. The system was tested for 12 h without severe fouling problems.

scholarly journals Experimental investigation of the cooling characteristics of a monobloc cast iron brake disc with fingered hub

2019 ◽  
Vol 234 (1) ◽  
pp. 85-97
Author(s):  
Marko Tirovic ◽  
Stergios Topouris ◽  
Glenn Sherwood
Keyword(s):  
Heat Dissipation ◽  
Cross Flow ◽  
Operating Conditions ◽  
Brake Disc ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Nusselt Numbers ◽  
Single Piece ◽  
Brake Discs ◽  
Cross Flow Velocity

The paper compares heat dissipation characteristics of two interchangeable ventilated brake discs, a standard solid hub and a newly developed fingered hub version, both single piece cast designs. The tests were conducted on a specially developed Thermal Flow Rig, which enables disc induction heating to 450°C and cooling for a range of rotational and air speeds, in parallel and angular cross flow. The Rig facilitated very accurate and repeatable experiments to be conducted for numerous combinations of operating conditions. From the recorded cooling curves, average heat transfer coefficients for convection and radiation were extracted and the results also presented in a generic form, using Nusselt numbers. The fingered design demonstrated superior convective heat dissipation, with the improvements varying depending on the rotational speed, air cross flow velocity and angle, as well as disc temperature. The gains were ranging from 3.5% to over 20%. The fingered design is 8.5% lighter and being a single piece cast disc, it remains inexpensive to mass produce.

scholarly journals Removal and transport mechanisms of arsenics in UF and NF membrane processes

2006 ◽  
Vol 4 (2) ◽  
pp. 215-223 ◽  
Author(s):  
Do Hee Kim ◽  
Kyoung Woong Kim ◽  
Jaeweon Cho
Keyword(s):  
Membrane Surface ◽  
Cross Flow ◽  
Operating Conditions ◽  
Reflection Coefficients ◽  
Transport Mechanisms ◽  
Flat Sheet ◽  
Charged Membrane ◽  
Cross Flow Velocity ◽  
Diffusion And Convection ◽  
Uf Membranes

In this study, the removal and transport mechanisms of ionized and non-ionized arsenics through NF and UF membranes were systemically investigated. The charge repulsion between the membrane surface and arsenic ions was an important mechanism for the rejection of ions by a charged membrane. In addition, the effect of J0/k ratio was dependent on the membrane and ion charge, but the cross-flow velocity was not significantly affected. Both diffusion and convection are proved to affect the transport of arsenic ions. The reflection coefficients (σ) of both UF and NF membranes increased with increasing pH; the reflection coefficients of arsenate were higher than those of arsenite under the same operating conditions. The spiral-wound module exhibited slightly higher arsenate removal than the flat-sheet module under the same operating conditions.

Influence of the spray drying operating conditions on the estimated drying kinetics of emulsion single droplets and the properties of microencapsulated chia oil

2021 ◽  
Vol 383 ◽  
pp. 302-317
Author(s):  
M. Gabriela Bordón ◽  
Noelia P.X. Alasino ◽  
Vanina Martínez ◽  
Regina Gauna Peter ◽  
Ramiro Iturralde ◽  
...  
Keyword(s):  
Spray Drying ◽  
Drying Kinetics ◽  
Operating Conditions ◽  
Single Droplets ◽  
Kinetics Of ◽  
Chia Oil

scholarly journals A Novel Hybrid LDC Converter Topology for the Integrated On-Board Charger of Electric Vehicles

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3603
Author(s):  
Vu-Hai Nam ◽  
Duong-Van Tinh ◽  
Woojin Choi
Keyword(s):  
Low Voltage ◽  
Operating Conditions ◽  
Maximum Efficiency ◽  
Battery Charger ◽  
Forward Converter ◽  
Vehicle To Grid ◽  
Circulating Current ◽  
In Series ◽  
Converter Topology ◽  
Output Capacitor

Recently, the integrated On-Board Charger (OBC) combining an OBC converter with a Low-Voltage DC/DC Converter (LDC) has been considered to reduce the size, weight and cost of DC-DC converters in the EV system. This paper proposes a new integrated OBC converter with V2G (Vehicle-to-Grid) and auxiliary battery charge functions. In the proposed integrated OBC converter, the OBC converter is composed of a bidirectional full-bridge converter with an active clamp circuit and a hybrid LDC converter with a Phase-Shift Full-Bridge (PSFB) converter and a forward converter. ZVS for all primary switches and nearly ZCS for the lagging switches can be achieved for all the operating conditions. In the secondary side of the proposed LDC converter, an additional circuit composed of a capacitor and two diodes is employed to clamp the oscillation voltage across rectifier diodes and to eliminate the circulating current. Since the output capacitor of the forward converter is connected in series with the output capacitor of the auxiliary battery charger, the energy from the propulsion battery can be delivered to the auxiliary battery during the freewheeling interval and it helps reduce the current ripple of the output inductor, leading to a smaller volume of the output inductor. A 1 kW prototype converter is implemented to verify the performance of the proposed topology. The maximum efficiency of the proposed converter achieved by the experiments is 96%.

Effects of alternating elliptical chamber on jet impingement heat transfer in vane leading edge under different cross-flow conditions

2021 ◽  
pp. 1-17
Author(s):  
K. Xiao ◽  
J. He ◽  
Z. Feng
Keyword(s):  
Heat Transfer ◽  
Velocity Ratio ◽  
Cross Flow ◽  
Leading Edge ◽  
Longitudinal Vortices ◽  
Impingement Jet ◽  
Flow And Heat Transfer ◽  
Impingement Heat Transfer ◽  
Cross Flow Velocity ◽  
The Cross

ABSTRACT This paper proposes an alternating elliptical impingement chamber in the leading edge of a gas turbine to restrain the cross flow and enhance the heat transfer, and investigates the detailed flow and heat transfer characteristics. The chamber consists of straight sections and transition sections. Numerical simulations are performed by solving the three-dimensional (3D) steady Reynolds-Averaged Navier–Stokes (RANS) equations with the Shear Stress Transport (SST) k– $\omega$ turbulence model. The influences of alternating the cross section on the impingement flow and heat transfer of the chamber are studied by comparison with a smooth semi-elliptical impingement chamber at a cross-flow Velocity Ratio (VR) of 0.2 and Temperature Ratio (TR) of 1.00 in the primary study. Then, the effects of the cross-flow VR and TR are further investigated. The results reveal that, in the semi-elliptical impingement chamber, the impingement jet is deflected by the cross flow and the heat transfer performance is degraded. However, in the alternating elliptical chamber, the cross flow is transformed to a pair of longitudinal vortices, and the flow direction at the centre of the cross section is parallel to the impingement jet, thus improving the jet penetration ability and enhancing the impingement heat transfer. In addition, the heat transfer in the semi-elliptical chamber degrades rapidly away from the stagnation region, while the longitudinal vortices enhance the heat transfer further, making the heat transfer coefficient distribution more uniform. The Nusselt number decreases with increase of VR and TR for both the semi-elliptical chamber and the alternating elliptical chamber. The alternating elliptical chamber enhances the heat transfer and moves the stagnation point up for all VR and TR, and the heat transfer enhancement is more obvious at high cross-flow velocity ratio.

scholarly journals Data-driven Modelling of Microfiltration Process with Embedded Static Mixer for Steepwater from Corn Starch Industry

2017 ◽  
Author(s):  
Laslo Šereš ◽  
Ljubica Dokić ◽  
Bojana Ikonić ◽  
Dragana Šoronja-Simović ◽  
Miljana Djordjević ◽  
...  
Keyword(s):  
Corn Starch ◽  
Desirability Function ◽  
Specific Energy Consumption ◽  
Cross Flow ◽  
Operating Conditions ◽  
Transmembrane Pressure ◽  
Static Mixer ◽  
Permeate Flux ◽  
Experimental Conditions ◽  
Starch Industry

Cross-flow microfiltration using ceramic tubular membrane was applied for treatment of steepwater from corn starch industry. Experiments are conducted according to the faced centered central composite design at three different transmembrane pressures (1, 2 and 3 bar) and cross-flow velocities (100, 150 and 200 L/h) with and without the usage of Kenics static mixer. For examination of the influence of the selected operating conditions at which usage of the static mixer is justified, a response surface methodology and desirability function approach were used. Obtained results showed improvement in the average permeate flux by using Kenics static mixer for 211 % to 269 % depending on experimental conditions when compared to the system without the static mixer. As a result of optimization, the best results considering flux improvement as well as reduction of specific energy consumption were obtained at low transmembrane pressure and lower feed cross-flow rates.

Studies of the uptake of macromolecules by cells. I. Uptake of proteins by cells of the Ehrlich–Lettré ascites carcinoma

1968 ◽  
Vol 46 (12) ◽  
pp. 1443-1450 ◽  
Author(s):  
Y. C. Choi ◽  
E. R. M. Kay
Keyword(s):  
Nucleic Acid ◽  
Cell Membrane ◽  
Binding Sites ◽  
Specific Binding ◽  
Protein Uptake ◽  
Specific Binding Sites ◽  
Model Protein ◽  
Uptake Process ◽  
Kinetics Of ◽  
Protein Treatment

The uptake of protein by cells of the Ehrlich–Lettré ascites carcinoma was characterized kinetically by using hemoglobin as a model protein. An attempt was made to show that the process is not an artefact due to nonspecific adsorption of protein to the cell membrane. The kinetics of the uptake process suggested that an interaction exists between the exogenous protein and specific binding sites on the membrane. Acetylation of hemoglobin enhanced the rate of uptake of this protein. Treatment of cells with neuraminidase, phospholipase A, and Pronase resulted in an inhibition of protein uptake. The experimental evidence for the uptake of hemoglobin was supported by evidence that L-serine-U-14C-labelled hemoglobin is transported into the cytoplasm and utilized subsequently, resulting in labelling of the nucleic acid nucleotides.

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