This project used high-fidelity CFD to assess scale-up of a novel household washing-machine microplastic/fibre filter (Matter’s Regen technology) toward industrial scale. Simulations accounted for rotating impellers, two-phase air–water flow, plus dispersed particles (microplastics and fibres), using our LES-LBM solver (M-startCFD). The results revealed scale-dependent issues in particle capture efficiency and flow distribution, informing design modifications and operational limits for larger throughaput versions of the device.