Optical particle sizers for on-line applications in industrial plants

We present three optical particle sizers properly conceived for different on-line applications in industrial plants. The first one is a diffraction-based particle sizer utilising an innovative optical scheme that allows the instrument to operate at very low particle concentration regimes (i.e. at extinction values as small as 10(-5)) in the size range 0.9-90 mum. The second one is based on the same principle of operation, but has been designed with a different optical configuration that makes it suitable for the characterisation of high concentration particle laden flows (like for e.g. pulverised coal downstream of the grinding mills) in the size range 3-300 mum. The third instrument is based on a multi-wavelength extinction technique and provides measurements over long optical paths (up to 10 m) in the 0.1-3 mum size range. (C) 2002 Elsevier Science Ltd. All rights reserved.