A novel method for efficient computations of a fluidized bed reactor with liquid injections is developed. It allows economical simulations for a reactor that contains multiple nozzles using a relatively coarse grid, while still accounting for the influence of particular features of individual nozzles. The method relies on patching variables in the near nozzle area obtained on the fine nozzle- scale grid onto the coarse reactor-scale grid followed by the solution of the flow equations elsewhere in the coarse grid domain. The procedure is tested for a small fluidized bed that permits both fine and coarse grid solutions. It was found that the developed procedure represents the flow adequately and allows for the distinction of different nozzle geometries. (C) 2013 Elsevier Ltd. All rights reserved.