A modal analysis technique for the on-line particle size measurement of pneumatically conveyed pulverised coal

The particle size distribution of the pulverised coal on a fossil fuel power station is an important and useful parameter for the efficient control of power generation. However, to put this parameter to its most effective use, it is necessary to measure if on-line. An investigation conducted into techniques used for the on-line measurement of particle size revealed a cost effective technique to achieve this goal. It shortly entails the measurement of the resonant or modal vibrations evoked in a structure when pneumatically conveyed particles collide with if. By analysing the frequency spectra of these evoked vibrations, the size distribution of the particles colliding with the structure can be determined. Results of experimental tests done on a pilot plant confirm the usefulness of this technique.