The Trickle bed reactors (TBRs) are multiphase reactor, which has gas-liquid-solid systems where gas and liquid flow downwards on fixed bed of catalyst. The TBRs have widely used in petroleum and chemical based industries.  Hydrodynamics studies in TBRs are crucial as it helps process optimization. This work measures the local liquid and gas holdups by Two-Tips Optical Probe (TTOP) measurement technique. The experiment was performed in 0.14 m diameter reactor made of acrylic glass filled with 3 mm glass bead which act as the solids. Water was used as the liquid phase while the air was used as the gas phase. The superficial velocities for both gas and liquid phase were in the range 0.03 m/s to 0.27 m/s and 0.004 m/s to 0.014 m/s respectively. Two-tips optical was fabricated in-house. The two optical fibers are arranged parallel to each other at a distance of 0.001 m. The signals with this probe can measure the local liquid and gas holdups. In addition, this technique also can identify the flow regimes in TBRs by analyzing the time series of the measurement of each tip of the probe statistically and chaotically. The results are compared with other techniques such as Gamma Ray Densitometry Technique. In this presentation results and findings are discussed.

Keywords: Trickle bed reactor; optical fiber probe; Phase Holdup; Flow Regime