Monitoring a lab-scale wurster type fluidized bed process by electrical capacitance tomography

Che, HQ; Wu, Mengyuan; Ye, JM; Yang, Wuqiang; Wang, HG

doi:10.1016/j.flowmeasinst.2017.09.005

Cited by 25 publications

(10 citation statements)

References 33 publications

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“…These studies involve filming of the flow, sampling techniques [5] and non-invasive techniques, such as some tomographic techniques. In the latter case, these techniques obtain information about the system through measurement of the electromagnetic, acoustic or electrical properties of the fluids [10][11][12][13][14][15]. In addition to the experimental studies, flow simulations have also been extensively developed.…”

Section: Introductionmentioning

confidence: 99%

Oil/water flow in a horizontal pipe—dispersed flow regime

Sanstos¹,

Garcı́a²,

Rasteiro³

et al. 2020

Int. J. CMEM

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In multiphase fluid flow, the formation of dispersed patterns, where one of the phases is completely dispersed in the other (continuous medium) is common, for example, in crude oil extraction, during the transport of water/oil mixture.In this work, experimental and numerical studies were carried out for the flow of an oil/water mixture in a horizontal pipe, the dispersed liquid being a paraffin (oil with density 843 kg m −3 and viscosity 0.025 Pa s) and the continuous medium a water solution doped with NaCl (1000 µS. cm −1 ). The tests were made for oil concentrations of 0.01, 0.13 and 0.22 v/v and velocities between 0.9 and 2.6 ms −1 of the mixture. Experimental work was performed in a pilot rig equipped with an electrical impedance tomography (EIT) system. Information on pressure drop, EIT maps, volumetric concentrations in the vertical diameter of the pipe and flow images were obtained. Simulations were performed in 2-dimensional geometry using the Eulerian-Eulerian approach and the k-ε model for turbulence modelling. The model was implemented in a computational fluid dynamics platform with the programme COMSOL Multiphysics version 5.3. The simulations were carried out using the Schiller-Neumann correlation for the drag coefficient and two equations for the viscosity calculation: Guth and Simba (1936) and Pal (2000). For the validation of the simulations, the pressure drop was the main control parameter.The simulations predicted the fully dispersed flow patterns and the pressure drop calculated when using the Pal (2000) equation for the viscosity calculation showed the best fit. The results of the images of the flows obtained by the photographs and simulations were in good agreement.

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Section: Introductionmentioning

confidence: 99%

Oil/water flow in a horizontal pipe—dispersed flow regime

Sanstos¹,

Garcı́a²,

Rasteiro³

et al. 2020

Int. J. CMEM

View full text Add to dashboard Cite

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“…Nowadays, capacitive tomography has widespread in the industry. [7] Efforts are being made to improvise the system to attain promising benefits from its analysis in the industry. In the flow measurement of solid particles, the nonhomogeneity of the solid particles is a critical issue.…”

Section: Introductionmentioning

confidence: 99%

Estimate Mass Flow Rate of Dense Phased Powder Solids

et al. 2020

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The complex multiphase gas-solid flow has always been a point of attraction for researchers over the past decade to explore the sensing techniques to sense and measure the mass flow. Weather dilute or dense phase flow, the gas-solid flow measurement generally requires velocity profile and volumetric concentration measurement to find the mass flow rate. The nature of the solids, the environmental factors-specially moisture adversely affects the sensor readings-specifically when it is non-invasive capacitive sensors. Gas-solid flow finds its applications in power plants, food, chemical, automobile, and pharmaceutical industries. This paper aims to explore the evolution of a novel approach of using load cell in conjunction with capacitive electrodes for calculating the mass flow rate of the solids.

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“…Electrical capacitance tomography (ECT) is a technique that can be used to reconstruct the solids distribution in a fluidised bed chamber and gives valuable information for control. Research was carried out to investigate fluidised bed drying (Chapin et al, 2005;Ge et al, 2016;Rimpila¨inen et al, 2012;Wang et al, 2009;Zhang et al, 2016), pellet coating (Che et al, 2018a) based on ECT. The image reconstruction algorithm for ECT includes Linear back-projection (LBP) (Xie et al, 1992), Landweber iteration (Yang et al, 1999), direct image reconstruction (Cao et al, 2009) and intelligent algorithms that are based on neural network (Marashdeh et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Control of pellets coating in a Wurster fluidised bed by means of electrical capacitance tomography

Che

Wang

et al. 2019

Transactions of the Institute of Measurement and Control

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Wurster fluidised bed is commonly used for coating pellets in the pharmaceutical industry. Normally, the control in a Wurster fluidised bed for coating is based on point-based measurement, that is, pressure and optical probes. However, the point-based measurement methods only provide local flow information and cannot reveal the cross-sectional flow dynamics characteristics and it is difficult to control the whole process with limited data. In this paper, electrical capacitance tomography (ECT) is applied to reconstruct the solids distribution in a lab-scale Wurster fluidised bed for coating pellets and the measurements are used in a control loop of the process. The flow regime is identified from the ECT images using a simple but efficient approach. The objective of control is to keep stable minimum fluidisation and avoid undesired flow regime in the region between the outside wall and the Wurster tube, such as intermittent, plug and defluidisation. To achieve this target, a PID controller is applied to keep a low volume fraction in the annular region by adjusting the fluidisation air rate, and bang-bang control is applied to a peristaltic pump used for spraying coating solutions based on the detected flow regime. It has been found that the proposed control scheme based on the ECT measurement is effective for keeping a stable flow regime, reducing the degree of pellets agglomeration and avoiding defluidisation.

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Monitoring a lab-scale wurster type fluidized bed process by electrical capacitance tomography

Cited by 25 publications

References 33 publications

Oil/water flow in a horizontal pipe—dispersed flow regime

Oil/water flow in a horizontal pipe—dispersed flow regime

Estimate Mass Flow Rate of Dense Phased Powder Solids

Control of pellets coating in a Wurster fluidised bed by means of electrical capacitance tomography

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