On fluid dynamics of lamella separator modelling and process optimisation

Abstract

The suspensions in the treatment of water, domestic wastewater and industrial wastewater can be separated into clarified fluid and solid matter by gravity settlers. Inclined plate settler (IPS) is a type of gravity settler. Its performance strongly depends on the inlet zone configuration. Three different inlet structures were used to develop a model that can describe the effect of the inlet configuration on the hydraulic characteristics of lab-scale IPS numerically and validate it experimentally. The results show that feeding the IPS by a nozzle distributor can enhance the hydraulic performance of the IPS. Based on the previous results, the response surface methodology (RSM) combined with numerical simulation was used to optimise this distributor. The optimisation of nozzle has improved the hydraulic performance, flow distribution between the settlers and the separation efficiency of the IPS. Finally, a sediment gutter on the plates with an inclination angle to collect the sediment and disposes it via a lateral outlets is suggested to improve the separation efficiency.