Design And Experimental Study Of The Pneumatic Type Ultrasonic Nozzle For WFGD

Wet flue gas desulfurization (WFGD) technology is mature, stable and efficient had beenwidely used whether at home and abroad. But the disadvantages of the complexity of thesystem and large equipment cost high consumption of maintenance and operation, it greatlyincreases the cost of thermal power plants.In the WFGD system, the atomization performances of the limestone slurry directlyaffect the rate and efficiency of the desulfurization reaction. And the nozzles are the keyequipments that affect the atomization performance of the limestone slurry. Now the pressurenozzles are generally used in the WFGD system, which’s structure is relatively simple, theatomization performances that is poor, can be affected by the medium pressure. New nozzleswill be needed to develop for improving the atomization, enhancing the desulfurizationefficiency and reducing the costs of desulfurization and power consumption.Studied the atomization mechanism of WFGD in the paper, obtained the relationship ofslurry droplet with and desulfurization reaction rate size and liquid-gas ratio. The results showthat The smaller the particle size, greater the desulfurization reaction rate, the higher thedesulfurization efficiency. When the liquid-gas ratio is certain, the smaller the particle sizes ofslurry atomization, the higher the desulfurization efficiency.Developed an efficient pneumatic type ultrasonic nozzle for WFGD. According to thegas-liquid principle and ultrasonic atomization mechanism, designed and developed thedouble casing structure of ultrasonic nozzle. Studies have shown that the main performanceparameters that affect the nozzle atomizing are liquid-gas ratio, the structure of the cavity andRafael nozzle. Finally determined and optimized the structure size and performanceparameters of the nozzle after calculations and experiments.Test bench is developed for four mechanical nozzles with efficient flue gasdesulfurization ultrasonic nozzle comparison test for atomization experiments. The working parameters of the simulation scene, and atomization were detected and analyzed. Droplet sizeof the gas flow pneumatic type ultrasonic nozzle are up to50-200um，is only about1/10of themechanical atomizing nozzles; The spray angle of the gas flow pneumatic type ultrasonicnozzle is up to85°and uniform droplet size distribution, better atomization coverage area.The flow of the ultrasonic nozzle is greater than the mechanical nozzle compared with thesame size and operating parameters. It can meet the requirement of flow.In summary, the flue gas ultrasonic nozzle with the advantages of large flow, smalldroplet size, uniformity distribution and lower energy consumption, is expected to be used inWFGD system to achieve the purpose of energy saving.