Void fraction measurements in large (0.3 m) diameter bubble column using Wire Mesh Sensor and Pressure transducers- Effect of sparger

Author

Afolabi Gabriel Ojo, CUNY City CollegeFollow

Date of Award

2019

Document Type

Thesis

Department

Mechanical Engineering

First Advisor

Masahiro Kawaji

Keywords

Wire Mesh Sensor, Pressure Transducer, Four Arm Sparger, Point Sparger, Void Fraction, Bubble Column, Expanded Height, Gas hold-up

Abstract

The importance of the accurate temporal and spatial measurements of the two-phase flow parameters in bubble columns is very well known. The aim of this research work is to report the spatial measurements of the void fraction distribution in a 30 cm diameter cylindrical bubble column using Wire Mesh Sensor (WMS) tomography and Pressure Transducers. Pair of WMS sensors, with a 64×64 wire configuration of each sensor, were installed which are separated by a distance along the axis of the bubble column. Wire Mesh Sensors and PTs Data were collected for time-averaged and transient with a sampling frequency of 1000 Hz respectively. The principle of Wire-Mesh Sensors (WMS) and algorithms for estimating the void fraction from the WMS raw experimental data have been discussed in great detail. The void fraction results obtained from the WMS are compared against the void fraction results obtained from the Pressure Transducers. Experiments were performed for seven superficial gas velocities, to cover both Homogenous and Heterogenous flows. Two different spargers (point sparger and four arm spargers) were used to study the effect of the sparger design on the hydrodynamics. The measurement uncertainty of the WMS and PTs for air-water two-phase flows is investigated by repeating the experiments. The effect of superficial gas velocity and sparger design on the radial and steady-state void fraction profiles have been reported. These experimental investigations disclose the quantitative measurements of the steady-state flow parameters which have not so far been reported, and this data can also be used by the theoretical CFD modelers for their simulation data validation.

Recommended Citation

Ojo, Afolabi Gabriel, "Void fraction measurements in large (0.3 m) diameter bubble column using Wire Mesh Sensor and Pressure transducers- Effect of sparger" (2019). CUNY Academic Works.
https://academicworks.cuny.edu/cc_etds_theses/1039