Dependence of energy consumptions on the type of mechanical mixer used in the biogas reactor

Abstract

Purpose. Investigation of the dependence of the energy consumption of mechanical mixers and determination of an energy-efficient type of mixing device to increase the energy efficiency of the biogas formation process and the profitability of further processing into thermal and electrical energy. Methodology. Determination and analysis of energy costs for mechanical mixers, comparison and determination of their energy consumption in the process of biogas formation, generalization of the results. Findings. Biogas technologies play an important role in the formation of a modern energy system. The profitability of which directly depends on the energy efficiency of the processes of intensification of anaerobic fermentation. The process of anaerobic fermentation of waste is long, so one of the main methods of intensification of biogas production is the mixing of waste during anaerobic fermentation. Despite the large number of different types of mixing devices and systems, the main task of mixing is to create a homogeneous substance with the same temperature, acidity and other physicochemical components at any point in the volume of the substance. There is a need to increase the energy efficiency of the processes of intensification of anaerobic fermentation and the profitability of further processing of biogas into heat and electricity. Ways to improve energy efficiency are in certain dependences of the energy consumption of mechanical mixers, the choice of an energy-efficient type of mixer, certain criteria that significantly affect the consumption of electrical energy for mixing, the study of the vectors of propagation of flows created by the mixer. The implementation of these actions will allow you to establish the optimal geometric dimensions of the mixer and significantly increase the energy efficiency of biogas plants and further processing of the resulting biogas into thermal and electrical energy. Originality. The analysis of the reasons for different values of the Euler criterion for mechanical mixers is carried out with the same mode of the substance motion, its level and volume in the tank and other equal parameters. A comparative analysis of energy costs for the most common types of mechanical mixers in biogas reactors is carried out. It has been established that the use of a two-tier paddle mixer, which has two blades per tier, requires the least amount of energy to mix waste in a biogas reactor with a volume . Practical value. The data presented in this paper can be used in the design, construction and modernization of biogas plants. The direction of necessary further scientific researches is determined, the realization of which will increase the energy efficiency of biogas production and the profitability of further processing of biogas into thermal and electric energy.