An experimental and analytical study to analyze hydraulic behavior of nozzle-type underdrains in porous media filters

•A set of experiments with a scaled sand filter were carried out.•Ergun equation underpredicts pressure drop in the whole sand filter.•Ergun equation does not take into account the effect of the underdrain.•We developed a new analytical model which considers a nozzle-type underdrain.•The new model i...

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