The effective removal of particulate matters from the flue gas emitted from Urea Prilling Tower is very essential to conform to the environmental standards. Based on particle capture theory, the user-defined-function (UDF) codes were written to implement the simulation of particle removal. A novel numerical simulation method is carried out to study the flow field and the effects of gas-phase loading factor, spray density, particle size and droplet size on the particles removal efficiency. The results show that the removal efficiency of particles above 10 mu m can reach 97%. But the removal efficiency of particles less than 10 mu m deteriorates with decreasing particle diameter due to the randomness of a fine particle movement. In addition, the improved empirical correlations of the removal efficiency were obtained based on numerical simulation, which provides the guidance for optimum design of a spray scrubber in practical engineering applications. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.