Experimental and numerical investigations on heterogeneous condensation of insoluble particles in the fluid catalytic cracking unit

In the fluid catalytic cracking (FCC) unit, cyclones possess very less efficiency in the separation of particles smaller than 5 μm. Heterogeneous condensation, one of the most promising preconditioning technologies, can be applied in the FCC unit to improve the particle removal efficiency of cyclones. In this paper, the lab-scale equipment on heterogenous condensation was established and tested. Based on experimental investigation, a novel numerical method was presented to simulate the process of movement and growth of particles in the growth tube. The effects of critical operational parameters, such as the wall film temperature, gas inlet temperature, gas flow rate, and particle number concentration, were studied. The results show that when the gas flow rate is 2 lit·min⁻¹, the average particle size at the outlet increased to 6.67 μm, and the number of particles smaller than 4 μm decreased to about 5%. Overall, this study guides for practical engineering applications.