The SPS machines are not designed to filter the particulates to be of acceptable size, level or concentration, unlike Wet Scrubbers, Electrostatic Precipitators, Diesel Particulate Filter DPF etc.
The reality is that finest and ultra-finest Particulates tends to behave like gas rather than a gas-solids mixture or simply can be transported by vapour. Is the reason why many filtering technologies are ineffective. However, SPS technology is post-combustion system or last stage of production...