Perforated plates are used widely in engineering applications and environmental control systems. The particular interest of this study is the flow through the sieve tray in a desulphurization tower. However, the full scale simulation to capture the details of perforated structures is usually too expensive and causes difficulties in the numerical-based optimal design. Our goal is to develop a fast and reliable computational framework to analyze the flow behaviors within the desulphurization tower. Therefore, the porous media model is used to replace the detail perforated structure. It utilizes additional source terms, in the momentum equations to compensate the pressure loss across the sieve tray. First, the unit cell computation is used to analyze the detail flow structure within a single perforated hole, and the inertial loss coefficient of the porous media model is obtained. The value is very consistent to the empirical equations from the previous literatures. Furthermore, the gas flow within a small scale desulphurization tower is simulated. Compared to the numerical simulation by the real perforated sieve trays, the porous media model can provide very comparable pressure drop and velocity distribution with much cheaper grid resolutions. As the number of the perforated holes increases to a certain threshold, the approximation of the porous media model can become very accurate. However, the uniformity of the incoming velocity and the corresponding inclination angle could affect the accuracy of the porous media model. A more advanced porous media model should be developed in the future. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.