An Estimation of Heat Recovery Performance in the Coke Dry Quencher

Abstract

The coke dry quenching method (CDQ) has an advantage over the coke wet quenching method from the following points: 1) not to worse the coke quality and 2) being convenient to recover the heat of hot coke. CDQ is a kind of counter-current mov-ing-bed heat exchanger where the quenching gas flows through the descending hot coke. The rational design procedure for the highly efficient CDQ is not, however, established yet. In this study, we try to estimate the characteristcs of heat and mass transfer in CDQ for improvement of the heat recovery performance. In the computation, the finite element method is used to fit with the geometrical connfiguration. As a result, the predicted outlet temperature of the quenching gas and the lump coke is in agreement with the experimental result. Both temperatures of the quenching gas and the lump coke exhausted from CDQ are decreased by the endothermic reaction between the lump coke and the very small contents of H₂, O₂, CO₂ in the quenching gas. In the CDQ having a radial diistribution of the lump coke diameter, computed results are as follows: the quenching gas deflects having a non-uniform velocity distribution and the outlet gas temperature and the heat collection per-formance are decreased.