Influencing Factors and Parameter Optimization of Automatic Backwash Performance of Disc Filters

Abstract

ABSTRACT Automatic backwash disc filters frequently encounter issues such as short effective filtration times, frequent backwashing and improper parameter configurations. To address these issues, two disc filter models were evaluated. Under the conditions of 20–30‐m 3 /h backwash flow, 60–80‐kPa critical head loss and 20–45s backwash duration, the recovery rates for both head loss and flow, backwash water consumption and effective operating time were analysed. Increasing the backwash flow rate increased hydraulic impact, improving head loss and flow recovery rates by 70%–80%. The influence of the backwash duration on the backwash performance plateaued. Higher critical head loss had little effect on water consumption but significantly prolonged the effective operating period. An integrated performance evaluation index was developed using the entropy weight method, and an optimal parameter equation was derived. This level of optimization can lead to substantial reductions in operational water and energy consumption, enhancing the overall sustainability of microirrigation systems. Optimization improved the evaluation index and overall backwash performance by 5%–10%. Segmental extrapolation and deviation correction further enhanced the universality and predictive accuracy of the equation. These findings provide theoretical guidance and practical reference for rational backwash parameter configuration.