In a typical catalytic trickle bed type of process reactor, capturing representations of steady-state flow features as well as situations like channelling or bypassing is a challenging task.Transmission-type industrial process tomography (PT) based on gamma radiation can beemployed in many chemical and process industries as a tool for localizing the problemarea for quick and economical troubleshooting. Industrial PT technology often makes useof either penetrating radiation like radioisotope based gamma rays, X-rays, microwaves orultrasonic waves. We have developed a new gamma-ray transmission tomography systemin collaboration with the Indian Oil Corporation Ltd. (IOCL R&D Unit, Faridabad, India). Thesystem makes use of thirty two scintillator based gamma-ray detectors in addition to ahost of other sub-systems. This paper evaluates the performance of the system consideringsystematic and automated data acquisition, capabilities of the reconstruction software aswell as experimental verification using actual flow dynamics in the process column to mapthe steady state three phase liquid gas flow distribution across a plane in the presence ofcatalyst.