Research

Single source gamma ray computed tomography (CT) technique is part of the dual source gamma ray computed tomography. The technique measures the time averaged cross sectional distribution of phases along the bed height for two phase flow systems (gas-liquid, gas-solid, liquid-liquid, liquid-solid) and for three phases if the solids phase is stationary (packed bed or structured bed). The data can be further processed to compute radial or diameter profile of phases. For each step of rotation, the detectors can be moved in a fine movement to produce more projection to enhance the special resolution. Depending on the detector collimation and the object to be scanned the spatial resolution can be about 1-2 mm. For each selected cross section along the reactor, the CT scan is usually performed for at least 2 hours or more depending on the column diameter to obtain time-averaged phase distribution of phases in good statistics. Image reconstruction is performed with software based on the Estimation-Maximization (EM) and Alternating Minimization algorithms. Advanced mathematical methodologies, algorithms and programs have been developed in-house and implemented along with the needed post-processing data to reconstruct the phase densities/holdups distribution. This technique if it is not rotated can be used as gamma ray densitometry