A novel column internal is proposed, named the tridimensional rotational flow sieve tray (TRST), which has a three-dimensional hollow structure that can make the gas form two kinds of flow pattern coupled with each other: one is rotational flow and the other is flow through the perforations. Using an air-liquid system, we experimentally measured the pressure drops (dry and wet) when gas-liquid flows concurrently downwards through the TRST. We also examined the effects of gas-liquid flux, various geometric parameters of the TRST (i.e. number of blades, twist angles of the blades, tray heights and sieve hole diameters), tray installation methods (forward and backward) and number of installed trays on the pressure drop. The results indicate that the pressure drop increases with increasing gas-liquid flux, number and twist angles of the blades, but decreases with increasing tray heights and sieve hole diameters. The pressure drop of the tray is largest in backward installation, smaller in first installed location and smallest in forward installation. Compared with other new types of trays, the pressure drop of the TRST is lower and there is a significant resistance performance advantage. In addition, according to the mechanism of gas-liquid flow in the TRST, we established the mathematical model of TRST performance in the range of operating conditions. The fitting values agree well with the experimental values. (C) 2018 Elsevier Ltd. All rights reserved.