A novel column internal was proposed, named tridimensional rotational flow sieve tray(TRST). Using CFD simulation and experimental methods, we examined the dry pressure drop and gas flow distribution when gas flows downward through the TRST. The results indicate that compared with other common trays, the dry pressure drop of TRST is lower (less than 70 Pa). In the TRST, there are two kinds of gas flows: one is the rotational flow between the adjacent two twisted sieve blades, the other is the flow through perforations at the sieve holes. They are coupled with each other. Subjected to diversion and restriction from the twisted sieve blades, in the upper part of the tray, the gas is at the stage of starting rotational flow, the velocity is lower and the static pressure is larger, both the forward and backward flow through perforations exist; in the middle and lower part of the tray, the gas is at the stage of full developed rotational flow, the velocity is larger, the static pressure is lower and the flow through perforations of gas is all in forward. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.