In order to provide a theoretical guidance for pulse-jet cartridge filters design, the optimized relationship between jet distance (the distance between nozzle and cartridge opening) and nozzle diameter was investigated in a semi industrial pulse-jet cartridge filter, using peak pulse pressure as an index to evaluate the cleaning effect. It is found that, with the increase of jet distance, the peak pulse pressure first increases and then decreases. Obviously, there is an optimum jet distance for each nozzle diameter. And their relationship was analyzed according to fluid dynamics, showing that the optimum jet distance increases gradually with decreasing nozzle diameter and a mathematical model for optimizing jet distance S and nozzle diameter is put forward: S = (D-d)/2 tan 22 43-0.87d+0.11d(2)/2. Finally, this model was verified both by experiments and literature, demonstrating that it can be used to optimize the jet distance when cartridge diameter and nozzle diameter were given. (C) 2014 Elsevier B.V. All rights reserved.