LAUSR

ABSTRACT In this study, the feasibility of two techniques for real-time monitoring of scale deposition thickness were evaluated. Traditional pressure drop measurements and a variant of the heat pulse monitoring technique which was developed in this study were tested and compared in a lab scale experiment. Measurements were performed on test pipes while transportation air was led through the conveying system. Coating layers of different thicknesses were applied to the inner walls of the test pipes to simulate scaling. Prediction models were calibrated from the experimental data by multivariate methods and were used to assess the performance of the techniques. It was found that the heat pulse method provided the most accurate predictions for scale thickness. The pressure drop method did not give acceptable results for the application considered in this paper. Results show that the heat pulse method is somewhat sensitive to changes in the feed air temperature. However, it will still provide reliable results for online monitoring of industrial applications in which the conveying air temperature is relatively stable.