A model of bed mass in propylene polymerization horizontal stirred bed reactor(HSBR)was proposed to explore the quantitative relationship between acoustic emission(AE)energy and bed mass

based on the mechanism of acoustic signals emitted by collision between particles and reactor wall.The system of air and polypropylene was used as an example and investigated at the bed mass range from 11.5 kg to 23 kg.It was found that singlepoint acoustic energy grew exponentially with increasing bed mass.Fitting results showed that the correlation coefficient was 0.9929 between AE energy and bed mass by using the model proposed.The feasibility of scaling up on an industrial plant was studied and test results were in accordance with the theoretical model.Therefore

singlepoint acoustic emission method makes it possible to monitor the bed mass online and further to predict whether the bed level is stable in HSBR

which is of great importance to optimize and better control the propylene polymerization process.