Calculation of energy costs of composite biomass stirring at biogas stations

The paper is devoted to the study of the equipment to produce biogas fuel from organic wastes. The bioreactor equipped with a combined stirring system ensuring mechanical and bubbling stirring is designed. The method of energy cost calculation of the combined stirring system with original design is suggested. The received expressions were used in the calculation of the stirring system installed in the 10 m³ bioreactor: power consumed by the mixer during the start-up period made N_z=9.03 kW, operating power of the mixer made N_E=1.406 kW, compressor power for bubbling stirring made N_C=18.5 kW. Taking into account the operating mode of single elements of the stirring system, the energy cost made 4.38% of the total energy received by the biogas station. (paper)