Vibration Analysis of Agitator Systems in Anaerobic Digestion Reactors for Process Stability Enhancement

Abstract

Agitator systems play a vital role in maintaining mixing efficiency, biomass uniformity, and process stability in anaerobic digestion reactors used for wastewater and organic waste treatment. However, continuous mechanical operation under variable loading conditions can induce excessive vibrations, leading to equipment degradation, energy losses, and reduced reactor performance. This study investigates the vibration characteristics of agitator systems in anaerobic digestion reactors to enhance operational stability and mechanical reliability. A comprehensive analytical and numerical evaluation was conducted to assess the influence of agitator geometry, rotational speed, shaft alignment, fluid interaction, and structural support conditions on vibration behavior and dynamic response. Finite element analysis and vibration monitoring techniques were employed to identify critical stress regions, resonance conditions, and structural instability during reactor operation. The study further examined the relationship between agitator-induced vibration and process parameters such as sludge viscosity, gas generation rate, and mixing intensity. Results demonstrated that improper rotational conditions and mechanical imbalance significantly increase vibration amplitude, resulting in elevated stress concentration and reduced component lifespan. Optimized agitator configurations and controlled operational parameters were found to improve dynamic stability, reduce mechanical fatigue, and enhance energy-efficient mixing performance. Comparative analysis revealed substantial reductions in vibration-induced operational disturbances and improved anaerobic digestion efficiency under optimized conditions. Additionally, predictive vibration assessment enabled early fault detection and supported preventive maintenance strategies for long-term reactor reliability.