Investigation of feed dynamics in clinker grinding mill by residence time distribution method

Abstract

Residence time distribution (RTD) analysis has been identified as one of the best experimental and classical tools for studying the performance of non-ideal chemical reactors and industrial circuits. In this study, RTD method was used to investigate feed dynamics in clinker grinding mill. The data was collected by introducing 40mCi Au- 198 as a tracer in the feed at the mill inlet. The gamma signal was determined with thallium activated NaI detector placed at the mill outlet. RTD curve of the mill was generated from which the mean residence time (MRT) was evaluated using the method of moments. The experimental MRT was 27.1 minutes and the theoretical MRT evaluated from plant parameters was 55.3 minutes. Mathematical models were used to fit the outlet tracer concentration signal of the experimental data. The feed dynamics in the mill was best described by the “perfect mixing cells in series with exchange’ model which fitted well with the experimental outlet response curves of the mill.