Particle measurement without dispersion does not work, therefore there are usually extensive accessories for laboratory instruments to separate various powders, grains and granules, only then you can measure almost everything exactly. Even in classical sieve analysis, mechanical dispersion takes place.
However, if the particles are to be measured directly in the process, continuously, without sampling and laboratory, then inline dispersion is rather the exception.
Parsum will show an extensive range of inline dispersers for its IPP series of inline particle probes at Powtech 2019. These small accessories, which are attached directly to the probe and operated with compressed air, dilute and separate particle streams with completely different properties. There are dispersers with low shear forces that treat sensitive granules very gently, while for fine particles below 100 µm from grinding processes, for example, dispersion is carried out with very high shear forces. As a result, even sticky, moist and strongly adhering particles can be well separated. Solutions are also available for liquid dispersion and sampling of dispersed partial streams for online measurement.
For example, the growth of particles in a fluidized bed or high-shear mixing process can be monitored in real time. A moisture content of 20 % and more does not affect the measurement. Even if disturbing powder layers form on the surface and the windows of the process chamber, the measuring optics of the particle probe remain clear, because in addition to dispersion, the compressed air flow used also ensures that the optical surfaces remain clear thanks to sophisticated jet guidance. In this way, cleaning intervals of several weeks to months can be achieved in continuous processes.
