CFD Simulation of Raschig Ring Packing Patterns in a Pilot Scale: Prediction of Mean Residence time
Nattaporn Chutichairattanaphum ¹ Phavanee Narataruksa ^1* Karn Pana-Suppamassadu ¹ Sabaithip Tungkamani ² Chaiwat Prapainainar ¹ และ Thana Sornchamni ^3
1 Department of Chemical Engineering, Faculty of Engineering, King Mongkut’s University of Technology North Bangkok
² Department of Industrial Chemistry, Faculty of Applied Science, King Mongkut’s University of Technology North Bangkok
³ Analytical & Petrochemical Research Department, PTT Research and Technology Institute, PTT Public Company Limited, Wangnoi, Ayutthaya

Mean Residence Time (MRT) was determined numerically for the pilot packed bed reactor filled with the ceramic raschig rings. Three well-defined patterns and one randomly packed bed were studied, where a tube-to-particle ratio (N) was around 7. A case study of Dry Methane Reforming (DMR) was investigated at 600 °C, 1 atm. Reactant feeding rates were varied in the range of 0.985 to 2.957 L/min. The MRTs of four difference packing pattern, namely, vertical-staggered (pattern 1), chessboard-staggered (pattern 2), reciprocal-staggered (pattern 3), and randomly packed bed were conducted using finite-element based Computational Fluid Dynamics (CFD). The results were shown in terms of E(t) function where a higher value of the E(t) function means greater deviation from the ideal plug flow. Results showed that chessboard-staggered pattern had the lowest E(t) values compared with all patterns and all feeding rates. To deeply representative results for the system configurations, the discussion on non-ideal behaviors of each structured packing can be made systematically in this work.