Using CFD simulation, we first investigated the flow field distribution of the tridimensional rotational flow sieve tray (TRST) under different structural parameters (i.e. number of the blades, twist angle of the blades, tray height and sieve hole diameter) and installation methods (forward and backward) when gas flows downward through the TRST. Secondly, we carried out a comparative study of three modified structures of the tray, i.e. no supporting ring, a closed internal cylinder and no sieve holes present. Finally, we studied the transformed situations of the rotational flow and propose a dimensionless correlation to evaluate the performance of the tray. The results show that, apart from the tray with a smaller twist angle of the blade, the gas flow field distributions for all the other types of trays are similar. When two trays are installed, the gas flow field of the second tray in a forward installation is obviously different to that of a backward installation. The transformed position of the rotational flow for most types of trays is about half the depth of the tray. After comprehensive evaluation, the optimized tray structures are identified as a configuration with 8 blades, a 90 degrees twist angle of the blades, a tray height of 40 mm, and sieve holes of 5 mm diameter. In addition, the tray should have open internal cylinder without a supporting ring. When a multi-tray is installed, the backward installation method should be adopted. (C) 2019 Elsevier Ltd. All rights reserved.