Adaptive Calibration of a Capacitance Tomography System for Imaging Water Droplets Distribution

Volume 1 ◽  
2004 ◽  
Author(s):  
W. Q. Yang ◽  
A. Chondronasios ◽  
S. Nattrass ◽  
V. T. Nguyen ◽  
M. Betting ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Electrode Pair ◽  
Liquid Droplets ◽  
Separation Processes ◽  
Low Concentration ◽  
Droplet Distribution ◽  
Adaptive Calibration ◽  
Wet Gas ◽  
Reference Measurements ◽  
Capacitance Tomography

A highly-sensitive electrical capacitance tomography (ECT) system based on an HP4284 impedance analyser has been developed and used to quantify low concentration multiphase flows in wet gas separation processes. The system hardware provides high accuracy (0.05%) and high resolution (10−17 F). The sensor was calibrated in an environmental chamber with solid samples of known permittivity over ranges of temperature and humidity. Adaptive calibration and adjacent electrode pair correction techniques were applied to image very low concentration profiles. This paper describes the techniques used and presents the experimental results obtained from a test flow rig called Twister, which has been designed to separate liquid droplets from wet gas streams. The test results over a range of operating conditions (20% to 95% humidity) demonstrate that the ECT system is capable of reconstructing clear images of the droplet distribution inside Twister. Changes as small as 1 gWater/kgAir in the droplets form liquid were detectable. It has also shown that the concentration of the condensable phase can be estimated quantitatively within 20% in comparison with the reference measurements.

Adaptive calibration of a capacitance tomography system for imaging water droplet distribution

2004 ◽  
Vol 15 (5-6) ◽  
pp. 249-258 ◽  
Author(s):  
W.Q. Yang ◽  
A. Chondronasios ◽  
S. Nattrass ◽  
V.T. Nguyen ◽  
M. Betting ◽  
...  
Keyword(s):  
Water Droplet ◽  
Tomography System ◽  
Droplet Distribution ◽  
Adaptive Calibration ◽  
Capacitance Tomography

scholarly journals Evaluation of bio-coagulants for colour removal from dye synthetic wastewater: characterization, adsorption kinetics, and modelling approach

Water SA ◽  
2020 ◽  
Vol 46 (2 April) ◽  
Author(s):  
IA Obiora-Okafo ◽  
OD Onukwuli ◽  
NC Eli-Chukwu
Keyword(s):  
Adsorption Kinetics ◽  
Molecular Layer ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Synthetic Wastewater ◽  
Organic Polymer ◽  
Good Prediction ◽  
Colour Removal ◽  
Separation Processes ◽  
Coagulant Dosage

Dye usage for industrial applications has been on the increase and these activities generate large amounts of dye-constituted wastewater that should be treated before environmental discharge or reuse. Various studies have shown the application of natural organic polymer (NOP) coagulants in dye removal from industrial wastewater. In this research, the coagulation performances of Vigna unguiculata (VU) and Telfairia occidentalis (TO) for colour removal from crystal Ponceau 6R dye synthetic wastewater was studied. The proximate compositions, structure, and surface morphologies of the coagulants were investigated using standard methods, i.e. Fourier-Transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). Colour removal was evaluated through the time-dependent decrease in particle concentration and thus growth of flocs. Effects of the process parameters, including pH, coagulant dosage, dye concentration (DC), settling time, and temperature were preliminarily tested and the best range experimentally determined. The optimal operating conditions established were pH 2, 800 mg∙L−1 coagulant dosage, 100 mg∙L−1 dye concentration, 300 min, and 303 K. The order of greatest removal was VUC > TOC with optimum efficiency of 93.5% and 90.7%, respectively. The values of K and α obtained for VUC and TOC were 8.09 x 10−4 L∙mg−1∙min−1, 1.7 and 9.89 x 10-4 L∙mg−1∙min−1, 1.6, respectively. Coagulation time, Tag, calculated and deduced from the particle distribution plot, showed a rapid coagulation process. Coagulation-adsorption kinetics indicated agreement with the pseudo-second-order model deducing that chemisorption is the rate-controlling step. It further indicates that particle adsorption on the polymer surfaces occurred mostly as a mono-molecular layer and according to the chemisorption mechanism. Cross-validation showed good prediction of the experimental data. The selected coagulants have the potential for application as efficient coagulants while also showing significant adsorption characteristics. The application of kinetics and modelling in separation processes involving particle transfer is especially required in wastewater treatment.

scholarly journals Experimental and statistical study for leaching of niobium pentoxide from Pakistani ore

2018 ◽  
Vol 24 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Muhammad Irfan ◽  
Muhammad Ahmad ◽  
Sadia Akhtar ◽  
Muhammad Khan ◽  
Muhammad Khan
Keyword(s):  
Particle Size ◽  
Reaction Temperature ◽  
Batch Reactor ◽  
Niobium Pentoxide ◽  
Mass Ratio ◽  
Separation And Purification ◽  
Separation Processes ◽  
Separation Science ◽  
Low Concentration ◽  
Environmentally Friendly Process

The growing demand for niobium pentoxide, based on its use in separation processes, established its prominent significance as a leading candidate in the field of separation science and technology. This study reports the extraction of niobium pentoxide from pyrochlore ore occurring in Sillai Patai, KPK, Pakistan. It is difficult to recover niobium pentoxide from Pakistani ore due to its low concentration. Niobium pentoxide is an important material used in manufacturing industries for different purposes. Most of the commercially employed extraction processes are associated with serious environmental impacts and are not efficient in extracting niobium pentoxide from low concentration pyrochlore. Alkali potash has been used for separation and purification of niobium pentoxide because it is efficient and an environmentally friendly process. The leaching of niobium pentoxide is carried out in a batch reactor using alkali potash as a leachant. Various process parameters, including ore particle size, reaction temperature, reaction time and alkali to ore mass ratio, were examined statistically during the leaching process. It was observed that reaction temperature and ore particle size were more significant compared to other parameters. The maximum percent recovery of niobium pentoxide (95%) was obtained at 280?C in 90 min, while keeping the ore particle size 44 ?m and alkali to ore mass ratio of 7:1.

scholarly journals Systematic Experimental Investigation of Segregation Direction and Layer Inversion in Binary Liquid-Fluidized Bed

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 177
Author(s):  
Alberto Di Renzo ◽  
Giacomo Rito ◽  
Francesco P. Di Maio
Keyword(s):  
Experimental Investigation ◽  
Operating Conditions ◽  
Industrial Processes ◽  
Process Unit ◽  
Separation Processes ◽  
Solids Concentration ◽  
Expansion Range ◽  
Surface Expansion ◽  
Density Ratios ◽  
Inversion Phenomenon

Multi-component liquid-fluidized beds are encountered in a variety of industrial processes. Often, segregation severely affects the performance of the process unit. Unfortunately, size-driven and density-driven separation processes may occur with a complex interplay, showing prevailing mechanisms that change with the operating conditions. For example, when the solids exhibit contrasting differences in size and density, even the direction of segregation can turn out hard to predict, giving rise for some systems to the so-called “layer inversion phenomenon”. A systematic experimental investigation is presented on 14 different binary beds composed of glass beads and ABS spheres with different size and density ratios and different bed composition. The analysis allows assessing the reliability of a model for predicting the segregation direction of fluidized binary beds (the Particle Segregation Model, PSM). By measurements of the solids’ concentration at the surface, expansion/segregation properties and the inversion voidage are compared with the PSM predictions, offering a direct means of model validation. Both the segregation direction throughout the expansion range and the value of the inversion voidage are compared. Extensive qualitative agreement is obtained for 12 out of 14 fluidized mixtures. Quantitatively, the average discrepancy between predicted and measured inversion voidage is below 5%, with a maximum of 17%.

Investigation of the Role of Droplet Transport in Mitigating Top of the Line Corrosion

CORROSION ◽  
10.5006/2764 ◽  
2018 ◽  
Vol 74 (8) ◽  
pp. 873-885
Author(s):  
Nicolas Jauseau ◽  
Fernando Farelas ◽  
Marc Singer ◽  
Srdjan Nešić
Keyword(s):  
Large Scale ◽  
Flow Region ◽  
Limited Range ◽  
Operating Conditions ◽  
Experimental Methodology ◽  
Liquid Droplets ◽  
Flow Loop ◽  
Droplet Entrainment ◽  
Droplet Transport ◽  
Large Scale Flow

The entrainment of liquid droplets, occurring in a limited range of gas and liquid flow conditions within the stratified flow region, could represent an effective way to transport a non-volatile liquid corrosion inhibitor through the gas phase and combat top of the line corrosion (TLC). However, such an approach is only viable if the inhibitor can reach the top of the pipe and deposit at a rate higher than the local rate of condensing water can dilute it. This work presents a combined modeling and experimental methodology to determine the onset of droplet entrainment from the bottom and deposition at the top of the line. A modeling approach predicting the droplet entrainment onset is proposed and validated against new multiphase flow data recorded in a large scale flow loop, at operating conditions similar to those encountered in gas-condensate production facilities. Additionally, TLC experiments were performed in the same flow loop under simulated water condensation conditions to measure the actual corrosion at different rates of inhibiting droplet deposition. The results confirm that the droplet entrainment/deposition can effectively mitigate TLC when operating parameters are accurately controlled.

Research on Low Concentration Municipal Wastewater Removal Rate with Chemical-Biological Flocculation and Suspended Medium Process

2012 ◽  
Vol 599 ◽  
pp. 387-390
Author(s):  
Xing Yu Bian ◽  
Xing Sheng Kang ◽  
Yi Li ◽  
Yu Lin Sun ◽  
Min Kong ◽  
...  
Keyword(s):  
Municipal Wastewater ◽  
Removal Rate ◽  
Pilot Scale ◽  
Pollutant Removal ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Optimal Operating ◽  
Operational Parameter ◽  
Low Concentration ◽  
Scale Test

In this paper, chemical and biological flocculation and suspended medium process was applied to treat low concentration municipal wastewater in a pilot scale test in order to find the optimum operational parameter. The results showed that: system on pollutant removal mainly on chemical and biological flocculation reaction pool, Under the optimal operating condition, CODCr, TP and SS removal efficiencies reached 75.5％, 76％and 90.5％ respectively, and the CODCr, TP, SS concentrations of effluent meet the National Wastewater Integrated Discharge Standard. The optimum operating conditions according to the local actual situation, running for more than half a year, for the optimization of control parameters for the contrast obtained.

Wet Gas Compressor Surge Stability

2015 ◽  
Author(s):  
Veronica Ferrara ◽  
Lars E. Bakken
Keyword(s):  
Flow Regime ◽  
High Speed ◽  
Transient Flow ◽  
Focal Point ◽  
Operating Conditions ◽  
Concept Design ◽  
Wet Gas ◽  
Compressor Surge ◽  
Inlet Conditions ◽  
The Impact

The new wet gas compression technology provides a big potential for improved recovery from new and depleting gas/condensate fields. The current technology is based on centrifugal and axial compressor principles, which offers both the benefits of well-known concept design and the drawbacks of erosion, fouling, surge and instabilities. These concepts are based mainly on the design of a traditional compressor. This partly reflects performance requirements for handling pure gas and partly the lack of a fundamental understanding of wet gas behaviour through an impeller stage. Process and operating conditions may vary considerably during start-up at gas only or completely filled with addition of liquid with an inlet and/or discharge transient flow regime. An advanced wet gas test rig has been designed to identify the fundamental mechanisms related to wet gas compressor surge and instability behaviour. The open-loop wet gas rig includes a single overhung impeller, sections of visualisation for the wet gas impeller inlet, discharge and diffuser. The paper reviews and exposes the instabilities and surge flow behaviour at the impeller eye. Main focuses are the shift in inlet flow regime, the impact on overall compressor stage performance and the ability to handle wet transient inlet conditions. Any flow separation and/or slip across the inlet and impeller eye section will alter the established dry gas design guide lines for compressors. Visualisation of the impeller inlet during surge progression is the focal point of the present study. The investigation is supplemented by fast Fourier transform (FFT) analyses and high-speed measurements.

Variable Inlet Guide Vane Effect on Centrifugal Compressor Performance in Wet Gas Flow

2016 ◽  
Author(s):  
Levi André B. Vigdal ◽  
Lars E. Bakken
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Flow Direction ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Compressor Stage ◽  
Guide Vanes ◽  
Wet Gas ◽  
Compressor Performance

The introduction of variable inlet guide vanes (VIGVs) upfront of a compressor stage affects performance and permits tuning for off-design conditions. This is of great interest for emerging technology related to subsea compression. Unprocessed gas from the wellhead will contain liquid condensate, which affects the operational condition of the compressor. To investigate the effect of guide vanes on volume flow and pressure ratio in a wet gas compressor, VIGVs are implemented upfront of a centrifugal compressor stage to control the inlet flow direction. The guide vane geometry and test rig setup have previous been presented. This paper documents how changing the VIGV setting affects compressor performance under dry and wet operating conditions. The reduced performance effect and operating range at increased liquid content are of specific interest. Also documented is the change in the VIGV effect relative to the setting angle.

Imaging wet gas separation process by capacitance tomography

2002 ◽  
Author(s):  
Wuqiang Yang ◽  
Van T. Nguyen ◽  
Marco Betting ◽  
Athanasios Chondronasios ◽  
Steve Nattras ◽  
...  
Keyword(s):  
Gas Separation ◽  
Separation Process ◽  
Wet Gas ◽  
Capacitance Tomography
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