关键词: 危险废物, 焚烧急冷塔, 数值模拟, 黏壁率

Abstract: In the flue gas purification system of hazardous waste incineration, the quench tower is used for rapid cooling of the tail flue gas to prevent the reformation of dioxins within the temperature range of 200-500 ℃. Aiming at the problems of corrosion and liquid leakage caused by droplet wall adherence in the quench tower of hazardous waste incineration, the quench tower of a hazardous waste incineration plant has been taken as an research object. Based on the Euler-Lagrange method, a numerical calculation model of the quench tower was established by considering the heat and mass transfer between droplets and flue gas and tracking the movement trajectories of droplets. The effects of nozzle position, atomization angle, and atomized particle size on flue gas cooling in the quench tower were mainly investigated, and the droplet wall adherence under different operating conditions was statistically analyzed. The results showed that the atomized particle size had the most significant effect on the flue gas cooling performance. When the atomized particle size was reduced from 250 μm to 123 μm, the average outlet flue gas temperature decreased from 515 K to 446 K. The atomization angle directly affected liquid accumulation and droplet wall adherence in the tower, and comprehensive analysis indicated that 30° was the suitable atomization angle for this quench tower. The flue gas cooling rate in the upper region of the tower could be accelerated by increasing the spray gun height. The research results provide certain guidance for improving the flue gas cooling rate and reducing the probability of droplet wall adherence in the tower.

Key words: hazardous waste, incineration quench tower, numerical simulation, wall adherence rate