Modeling of an industrial double-roll crusher of a urea granulation circuit

Since for granulation processes the crusher operation has a decisive influence on the system stability, a reliable mathematical model to represent an industrial double-roll crusher of a urea granulation circuit is provided in this work. The crusher was described by the model given by Austin et al. [Austin L.G., Van Orden D.R., Perez J.W. A Preliminary Analysis of Smooth Roll Crushers, International Journal of Mineral Processing, 6 (1980), 321–336.] for mineral processing. The breakage parameters estimation was based on industrial data. The experimental particle size distributions of the feed, intermediate and product streams were obtained from large-scale crushers belonging to a urea granulation plant with a nominal capacity of 1 million tons/year. The results indicate that the model reproduces in a very accurate way the performance of this type of crushers, being a useful tool to: a) optimize the gap setting to meet specific crushed particle size distribution requirements and b) be included as a mathematical module in a plant simulator of the whole urea granulation circuit.