Numerical study of particle deposition and removal behavior in the water-cooled flue of a submerged arc furnace

Abstract

To solve the issue of fouling in traditional insulated flues, this study proposed a coil type water-cooled flue. Firstly, a comprehensive fouling model was developed based on the Johnson-Kendall-Roberts (JKR) theory and the Grant and Tabakoff particle-wall rebound model to simulate particle deposition, rebound, and removal behaviors within the water-cooled flue. Then, the effects of the cooling water inlet velocity, wall roughness, and inflection angle of tee section on the particle fouling characteristics were investigated. The results show that the particles are primarily deposited in the furnace mouth section, the external corners of the flue between sections I to III, the tee section, and the end of the blind pipe section within water-cooled flues owing to inertial collisions, low-velocity vortices, and thermophoretic force. Additionally, as the inlet velocity of cooling water increases from 0 to 1.6 m/s, the particle fouling mass decreases from 8.63 to 0.48 kg at t = 200 h. Conversely, as wall roughness increases from 0.1 to 1 mm, the particle fouling mass increases from 0.49 to 0.72 kg at t = 18 h. Furthermore, when the inflection angle α of the tee section increases from 60° to 110°, the fouling mass decreases from 0.54 to 0.48 kg at t = 18 h. Based on the comparative study of water-cooled and insulated flues, the water-cooled flue has a significant advantage in reducing particle deposition. To optimize particle deposition, the optimum inlet velocity of cooling water and the angle α are 1.2 m/s and 90°, respectively.