Simulation study on atomization characteristics of swirl nozzle for dust removal of coke dry quenching

Abstract

To study the atomization characteristics of nozzles during the wet dust removal process of coke dry quenching (CDQ), the swirl nozzle, plain orifice nozzle, air-blast atomizing nozzle, and effervescent atomizing nozzle commonly used in engineering were simulated. Droplet distribution and particle size produced by different types of nozzles were obtained by using Fluent software. The simulation was performed using the realizable k-ε turbulence model, the discrete phase model (DPM), and the Taylor analogical breaking (TAB) model. While simulating the atomization characteristics of pressure swirl nozzle at different diameters and pressures, it was found that a nozzle with a diameter of 1.5 mm produced smaller droplet sizes and a more uniform distribution. The droplets near the nozzle had a small size, were affected by airflow and gravity, and collided with other droplets during migration, resulting in the increase of some droplet size. At the water supply pressure of 10 or 12 MPa, the size of almost atomized droplets was below 100 μm. Diameter of 1.5 mm pressure swirl atomizing nozzle at the water supply pressure of 12 MPa is the preferred working conditions of CDQ dust removal. When Ca(OH)₂ solution was used as the medium for atomization dust removal and SO₂ adsorption, the spray particle size range was 4.44 × 10⁻⁵ ~ 2.94 × 10⁻⁴ m, which was smaller and more uniform than when the water was used as the medium. This study could provide preliminary data reference for the collaborative removal of dust and gaseous pollutants in the wet dust removal process of CDQ.