Transesterification of Sunflower Oil in Microreactors

Abstract KOH catalyzed transesterification of sunflower oil using methanol has been studied in different types of microreactors. All the microreactors consist of a serpentine microchannel etched in a glass chip but have different types of microfluidic junctions (dispersing devices). First microreactor consists of a T-type microfluidic junction. The second microreactor has a †-type microfluidic junction. The third microreactor uses a split and recombine micromixer to generate the dispersion. Effects of temperature, flow rate, and feed molar ratio on the conversion of triglyceride (TG) have been studied. In some cases, conversion of TG is not found to change monotonically with change in flow rate. An attempt has been made to explain this seemingly unusual trend, and the explanations are substantiated using the liquid–liquid two-phase flow patterns observed using a high-speed image acquisition system. The results from the experiments conducted in this study indicate that it is possible to get very high TG conversion (>90%) with residence time less than a minute.

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Experimental Characterization of a Modified Airlift Pump

Volume 7: Fluids Engineering Systems and Technologies ◽

10.1115/imece2014-39899 ◽

2014 ◽

Author(s):

Afshin Goharzadeh ◽

Keegan Fernandes

Keyword(s):

Water Flow ◽

Flow Rate ◽

High Speed ◽

Water Flow Rate ◽

High Speed Photography ◽

Two Phase ◽

Inner Diameter ◽

Airlift Pump ◽

Flow Map ◽

Churn Flow

This paper presents an experimental investigation on a modified airlift pump. Experiments were undertaken as a function of air-water flow rate for two submergence ratios (ε=0.58 and 0.74), and two different riser geometries (i) straight pipe with a constant inner diameter of 19 mm and (ii) enlarged pipe with a sudden expanded diameter of 19 to 32 mm. These transparent vertical pipes, of 1 m length, were submerged in a transparent rectangular tank (0.45×0.45×1.1 m3). The compressed air was injected into the vertical pipe to lift the water from the reservoir. The flow map regime is established for both configurations and compared with previous studies. The two phase air-water flow structure at the expansion region is experimentally characterized. Pipeline geometry is found to have a significant influence on the output water flow rate. Using high speed photography and electrical conductivity probes, new flow regimes, such as “slug to churn” and “annular to churn” flow, are observed and their influence on the output water flow rate and efficiency are discussed. These experimental results provide fundamental insights into the physics of modified airlift pump.

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Visual Criteria for Measuring Two-phase Flow Rate in Venturi with Flow Homogenizer

Journal of Heat Transfer ◽

10.1115/1.4030475 ◽

2015 ◽

Vol 137 (8) ◽

Author(s):

Sangho Sohn ◽

Jaebum Park ◽

Dong-Wook Oh

Keyword(s):

Flow Rate ◽

High Speed ◽

Two Phase Flow ◽

Volume Fraction ◽

Differential Pressure ◽

Phase Flow ◽

Two Phase ◽

3 Dimensional ◽

Lower Amplitude ◽

Gas Volume

A simple use of Venturi might be used to measure two-phase flow rate within relatively low GVF(gas volume fraction). Upstream flow entering Venturi can be improved with installed flow homogenizer which is easily fabricated by 3-dimensional printer with multiple holes. Simultaneous measurement between high-speed flow visualization and dynamic differential pressure measurement was made to find visual criteria for two-phase flow rate measurement with different GVF ranged from 0% to 30%. It was observed that the two-phase flow rate can be reliably measured up to 15% of GVF using flow homogenizer. FFT(Fast-Fourier Transform) results proved that the long flow homogenizers (type 2 and 4) showed a lower amplitude of differential pressure (Δp) than the short flow homogenizers (type 1 and 3) respectively. So the optimized flow homogenizer can be useful to measure two-phase flow rate at low GVF.

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Kinetic Characteristics of Si3N4 CVD

MRS Proceedings ◽

10.1557/proc-250-47 ◽

1991 ◽

Vol 250 ◽

Cited By ~ 1

Author(s):

W. Y. Lee ◽

J. R. Strife ◽

R. D. Veltri

Keyword(s):

Deposition Rate ◽

Mass Spectroscopy ◽

Flow Rate ◽

Molar Ratio ◽

Kinetic Characteristics ◽

Temperature Range ◽

Time Flow ◽

Effects Of Temperature ◽

Temperature Time

AbstractThe CVD of Si3N4 from SiF4 and NH3 gaseous precursors was studied using a hotwall reactor in the temperature range of 1340 to 1490°C. The effects of temperature, time, flow rate, and SiF4/NH3 molar ratio on deposition rate and axial and radial deposition profiles were identified. The decomposition characteristics of pure NH3 and SiF4 were studied utilizing mass spectroscopy and compared to thermodynamic predictions.

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Influence of air–water two-phase flow on the performance of a high-speed inducer

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/0954408920933476 ◽

2020 ◽

Vol 234 (6) ◽

pp. 588-599

Author(s):

Baoling Cui ◽

Mingzhe Cai ◽

Yifan Li

Keyword(s):

Flow Rate ◽

High Speed ◽

Volume Fraction ◽

Flow Channel ◽

Turbulence Energy ◽

Incoming Flow ◽

Two Phase ◽

Rate Condition ◽

Cavitation Performance ◽

Air Volume

This study is to reveal the influence of incoming flow containing air on the internal flow and performance of a high-speed inducer. Numerical calculations were performed herein under different air volume fraction conditions based on the shear-stress transport turbulence model and the Eulerian–Eulerian heterogeneous flow model. The external characteristic, cavitation performance and visualization experiment were conducted under the air–water two-phase condition. As a result, the effect of incoming flow containing air under small flow rate condition on the decline of the inducer head was larger than that under large flow rate condition. The proper air volume fraction was beneficial to the improvement of the inducer cavitation performance. As the air volume fraction increased, the pressure gradients in the axial and radial directions of the inducer gradually reduced and the supercharging performance of the inducer also worsened. The flow near the hub in the flow channel became messy, and the turbulence energy increased. The air mainly concentrated in the leading edge rim and the low blade height region near the hub in the flow channel. The air expanded in the circumferential, radial and axial direction as the air volume fraction increased.

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Design a High Speed Multiplier using Two Phase PPA

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.k1023.09811s219 ◽

2019 ◽

Vol 8 (11S2) ◽

pp. 146-149

Keyword(s):

High Speed ◽

Two Phase ◽

Ripple Carry Adder ◽

Product Generation ◽

Different Types ◽

Effective System ◽

Parallel Prefix ◽

Three Stages ◽

Prefix Adder ◽

Prefix Adders

Basically, multiplier is an efficient superconductor logic which performs various switching operation. Here different types of adders are analysed using different methodologies. In this paper we introduced a multiplier using proposed PPA. It uses parallel prefix adders in their reduction phase and it is an effective system for faster results and optimised. The entire operation of proposed system depends upon three stages they are multiplier partial product generation, reduction stages and parallel prefix adder which is discussed in below sections. The delay gets reduced by achieving low logical depth in the system. So the Proposed system reduces the delay. From the proposed system we can observe that there is a reduction in delay and complexity. Compared to ripple carry adder and carry save adder, proposed system gives better results.

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Experimental Study on Hydraulic Characteristics of Pneumatic Lifting Pump

Water ◽

10.3390/w12020388 ◽

2020 ◽

Vol 12 (2) ◽

pp. 388

Author(s):

Juanli Zuo ◽

Fengchao Li ◽

Ning Zhang ◽

Denghui He ◽

Wen Wang ◽

...

Keyword(s):

Theoretical Model ◽

Flow Rate ◽

Liquid Flow ◽

High Speed ◽

Two Phase Flow ◽

Liquid Flow Rate ◽

Bubble Formation ◽

Phase Flow ◽

Hydraulic Characteristics ◽

Two Phase

A pneumatic lifting pump is used in sewage treatment, offshore oil production, and other fields because of its simple structure and strong practicability. In order to study its internal hydraulic characteristics and gas-liquid two-phase flow, this paper carries out experimental research on the influence of different air intake modes and riser diameters on the performance of a pneumatic lifting pump. The air-water two-phase flow pattern in the riser and motion characteristics of bubble formation at the nozzle are obtained by a high-speed camera. Through theoretical analysis, the theoretical model of a pneumatic lifting pump is established, and experimental results verify the theoretical model well. The results show that when the submergence ratio is constant, the lifting efficiency decreases with the smaller intake area under different intake areas; and the influences of different holes distributions on liquid flow rate and lifting efficiency are not significant under the same intake area. At the same submergence ratio, the smaller the riser diameter, the smaller the final lifting liquid flow rate and the larger the lifting efficiency peak value.

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Jet Fuel Cavitation in a Converging Diverging Nozzle

Volume 2: Fora, Parts A and B ◽

10.1115/fedsm2007-37108 ◽

2007 ◽

Cited By ~ 3

Author(s):

Michael P. Davis ◽

Patrick F. Dunn ◽

Flint O. Thomas

Keyword(s):

Void Fraction ◽

Flow Rate ◽

High Speed ◽

Primary Source ◽

Phase Region ◽

Bubble Nucleation ◽

Two Phase ◽

Component Mixture ◽

Fuel Gas ◽

Nozzle Flows

The focus of this research proposal is the experimental characterization of fuel cavitation in flow through a converging-diverging nozzle. Cavitation of fuel presents additional complexities (as compared to that in water) because fuel is a multi-component mixture. In any practical engineering environment, large quantities of solid microparticles are resident in the fuel. Gas nuclei trapped on these microparticles has been shown to enhance bubble production in water, and their effect on fuel cavitation is an issue that will be investigated. Measurements also will be made with cavitating water for comparison. A converging-diverging nozzle was chosen as the means for producing cavitation because its type of area constriction is similar to other flow devices such as valves and pumps. Cavitating C-D nozzle flows also have been modeled extensively in the literature. The data that will be acquired include axial pressure profiles, nozzle flow rate, high-speed images of the cavitating region, axial void fraction profiles, and axial velocity profiles. Pressure, velocity, and flow rate data will be used to determine the pressure ratios and limiting mass flow rates when the nozzle is choked. High speed images will be used to identify the structures present in the two-phase region (whether the gaseous voids are spherical bubbles or amorphous slugs. Axial void fraction data will provide information on gas evolution in the flow. Experimental data for cavitating nozzle flows are limited to water cases where bubble nucleation is not a primary source of the two-phase mixture. The proposed research hopes to provide detailed pressure, void-fraction, and velocity measurements for comparison with existing models. The main differences between fuel and water cavitation will be highlighted.

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The Flow of Slugs in Horizontal, Two-Phase Pipelines

Journal of Energy Resources Technology ◽

10.1115/1.2905707 ◽

1990 ◽

Vol 112 (1) ◽

pp. 20-24 ◽

Cited By ~ 9

Author(s):

G. E. Kouba ◽

W. P. Jepson

Keyword(s):

Liquid Film ◽

Froude Number ◽

High Speed ◽

Liquid Fraction ◽

Flow Characteristics ◽

Translational Velocity ◽

Two Phase ◽

Different Types ◽

Channel Hydraulics ◽

Mixture Velocity

The flow characteristics in horizontal slug flow are studied experimentally in the Harwell Laboratory 150-mm-dia pipeline. If a frame of reference is taken as moving with the translational velocity of the slug, measurements of the Froude number in the liquid film ahead of the slug were always greater than unity while the Froude number within the slug was in general less than unity. This illustrates a change in flow from super to subcritical flow and the presence of a hydraulic jump. Different types of flow are noticed using high-speed video equipment and these types closely resemble those reported by open-channel hydraulics tests. The distribution of gas in the slug body is only homogeneous at high-mixture velocities and the effect of buoyancy on the gas is more noticeable at low gas velocities. The liquid fraction in the slug is shown to be directly dependent on the Froude number in the liquid film. The ratio of the translational velocity of the slug to the mixture velocity decreases continuously from 2.0 at low-mixture velocities to 1.25 and a mixture velocity of approximately 3m/s. After this point, it remains constant at 1.25.

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