Ammonia Recovery Study In Flue Gas Desulphurization By Ammonia Method

Aiming at the problem of drastic ammonia volatilization in the desulfurization tower of flue gas desulfurization technology of petroleum refinery, develop and design an ammonia recovery device which includes a spray tower and a mist eliminator. In the spray tower, absorb the volatile ammonia from the desulphurization using numerous droplets sprayed by a spiral nozzle; after ammonia absorption, fine droplets carried away from the spray tower by the flue gas should be separated by the mist eliminator, avoid the secondary pollution of the ammoni, and guarantee to meet the draining standard of the flue gas.Based on the two-film theory, carry out a study for the ammonia absorption process, deduce a model of the ammonia absorption efficiency,make sure that the main operating parameters affecting the absorption efficiency are empty tower gas velocity, liquid-gas ratio and height of the absorption region; through the orthogonal experiment for each parameter, draw the conclusion that the major and minor relationship of these parameters is empty tower gas velocity > liquid-gas ratio > height of the absorption region; combined with the experiments of absorption efficiency and pressure loss of each operating parameter, draw the conclusion that the best region of these parameters: empty tower gas velocity is 4m/s, liquid-gas ratio is 0.8L/Nm3, height of the absorption region is 0.8m, the ammonia absorption efficiency is 90.5% at this moment, ammonia content at the outlet is lower than 20ppm, and the tower pressure drop is 140Pa; based on the experimental data of tower pressure loss, fit a pressure loss equation for the tower The predicted pressure loss by model is in good agreement with experimental data, and this equation has a certain reference value for the industrial scale-up design of the spray tower.Finally carry out an experimental study for the separation performance of the mist eliminator, draw the conclusion that the best region of parameters: empty tower gas velocity is 3.5m/s, blade number 12, blade elevation angle is 25°, height of the swirling zone is 0.4m, the separation efficiency is 99.2% at this moment, and the pressure drop is 720Pa; based on the experimental data of the pressure drop, fit a pressure loss equation for the mist eliminator The predicted pressure loss by model is in good agreement with experimental data, and this equation has a certain reference value for the industrial scale-up design of the eliminator.