On the development of a continuous chute height measurement using vibrations

For optimum feed conditions for the individual mills of a milling train, the amount of shredded cane or prepared cane in the feed chutes needs to be kept at a constant level. In Australian sugar mills, the height of prepared ,cane in the feed chute, normally referred to as the chute height, is generally measured using a discrete, multi-probe, electrical conductivity sensor developed by the Sugar Research Institute (SRI). The coarse digitisation of the chute height that results, unfortunately, is sometimes not adequate for the uniform feeding of the crushing mills. In this paper, encouraging results of a new method for the continmms measurement of chute height are presented, which use the vibrations in the structure of the chute caused by the connected rotating machinery. By sensing the vibration levels at two positions on the side of a chute and using spectral analysis techniques as well as multilinear regression, a good correlation was achieved between certain spectral components and the chute height. It is believed that this is the' first time that a continuous chute height measurement system has been successfully demonstrated.