ECVT validation with applications to gas-solid fluidization

Fei Wang, Qussai Marashdeh and Liang-Shih Fan*

William G. Lowrie Department of Chemical and Biomolecular Engineering The Ohio State University, 140 W 19th Ave, Columbus, OH 43210, USA

ABSTRACT

In this paper, real-time and three-dimensional bubble/void dynamic flow behaviour in a 4-in ID gas- solid fluidized bed is investigated using electrical capacitance volume tomogramphy (ECVT). ECVT is a three-dimensional real-time non-intrusive technique for fast volume imaging of multi-phase flow systems. In this work, ECVT measurements are verified using a fiber optic probe measurement system, pressure transducer system, and 2D electrical capacitance tomography (ECT) by measuring the solids holdup of the fluidized bed. The time-averaged and transient characteristics of the three- dimensional gas-solid flows in the bubbling and turbulent fluidization regimes in the gas-solid fluidized bed are studied. The instantaneous properties and the three-dimensional shape of the rising bubbles and bubble coalescence in the bubbling regime are also quantified. A threshold method is used to identify the boundary of a bubble imaged using ECVT. This threshold method defines the bubble shape and size by setting a maximum concentration for the bubble, a threshold value is usually determined empirically.

Keywords Electrical capacitance volume tomography, ECVT, gas-solid fluidization, bubble coalescence