Abstract. At the moment there is no effective way to clean the flow of the turbine unit, which is justified from an economic point of view. It is important to understand how deposits affect compressor performance and the need to clean contaminants. In the available literature, such studies are not described. The computational the model stage domain for the study includes the following elements: inlet pipe, impeller, bladeless diffuser, swivel elbow, backward guide apparatus, outlet pipe. For calculations, the computational fluid dynamics methods in the Ansys software package were used. A numerical experiment was carried out in six mass flow rate variants, two impeller revolutions  variants, and three different sediment thicknesses in the flow part variants. Based on the numerical experiment the results, the calculated machine operating modes characteristics are constructed. The analysis revealed that the studied deposits cause a drop in the stage characteristics by 1.5-2%. Losses in the stage increase in proportion the thickness deposits in the compressor flow part.