Measurement technique for the on-line detection of fines in a fluidized bed

In many industrial applications knowledge of the particle size distribution in a fluidized bed and in particular knowledge of the proportion of fines, is extremely important in order to maintain good fluidization quality in the bed, and to prevent too many particles from leaving the cyclones in the gas stream. A common method of monitoring particle size in a laboratory situation is to take a sample of particles from the fluidized bed and use equipment such as a laser diffraction device to analyze the sample, which can be a cumbersome procedure. The objective of this study was to develop an online tool to monitor the proportion of fines in a fluidized bed. A novel online measurement technique for the detection of fines in fluidized beds was developed, which includes a correlation that relates the triboelectric signal to the proportion of fines in the bed.

A novel online measurement technique for the detection of fines in fluidized beds relates the triboelectric signal from a simple wire in the bed to the proportion of fines in the bed. wt%(<90μm)=0.936Vg-0.895i¯1.27 Where Vg   is the fluidization velocity and i¯ is the mean triboelectric signal..Figure optionsDownload as PowerPoint slideHighlights
► On-line monitoring of the proportion of fines in fluidized solids is of great industrial interest.
► It is currently very difficult.
► This paper presents a new, simple triboelectric method for the on-line monitoring of the proportion of fines.