Evaporation experiment and numerical simulation study of desulfurization wastewater in high-temperature raw gas

Abstract

This study adopts Fluent software to perform a numerical simulation on the evaporation of desulfurization wastewater, which is based on the experimental study of spraying desulfurization wastewater to the high-temperature raw gas (around 750 °C) inside the single riser of industrial coke oven. Regarding to the results, a further optimization was applied to the core-part nozzle structures of spraying wastewater in the experimental plant. The results indicated that the farthest distance of the droplets movement calculated by the modified formula We = f(T) was 0.051 m at 800 °C, which is more consistent with the experiment. When the flow rate of raw gas was increased from 0 m3/h to 700 m3/h, the dispersion degree of droplet particle trajectory was enlarged from range −0.181−0.174 m to −0.308−0.246 m on the x-axis, and the time that the droplet particles reached the gas flow rate accelerated from 0.007 s to 0.02 s. The relationship between the riser’s average temperatures before and after spraying desulfurization wastewater was T = 568.49In(T0) − 3151.9. It was consistent with the actual value. Within the coking time of 20 h, the average temperature of the riser after evaporation was 620.44 °C and the average evaporation time was 0.0025 s, when the desulfurization wastewater was sprayed at 3 m away from the water seal of the riser. The optimized injection system according to the simulation results has improved the treatment effect of the wastewater in the experimental plant.