Characteristic Research On Primary Atomization Of Spray Evaporation Of Desulfurization Wastewater

Flue evaporation technology has now become one of the hotspots in the research and treatment of desulfurization wastewater.The process is atomizing the desulfurized wastewater after pretreatment and concentration and spraying it into the flue ahead of the dust collector,and using the waste heat of the flue gas to evaporate the wastewater.The soluble matter separated out from the wastewater,together with the insoluble matter and the fly ash in the flue gas,are captured and collected in the following dust collector,so as to achieve the goal of zero discharge of wastewater.The use of flue gas waste heat to evaporate desulfurization wastewater mainly involves two processes,atomization and evaporation,in which atomization is divided into two parts:primary atomization and secondary atomization.The characteristics of primary atomization are related to the subsequent atomization and evaporation efficiency,and there are currently few related simulations.By changing the geometry parameters of the nozzle and the properties of the working fluid,the fluid pattern and characteristics inside the nozzle and its near field are simulated.The relevant characteristics of the atomization have been studied and explained in detail,which has a positive guiding significance for the design of the nozzle.The geometry parameters of the nozzle have important influence on the nozzle discharge coefficient,the thickness,velocity and the spray angle of the liquid sheet.The discharge coefficient is positively correlated with the square of the nozzle outlet area.The thickness of the liquid sheet varies from position,and the thickness factor is related to the maximum width of the nozzle outlet.According to the velocity distribution of the liquid sheet,the velocity calculation formula is put forward,and it is in good agreement with the simulated value under certain conditions.The spray angle is confirmed to be related to the nozzle outlet area,discharge coefficient and thickness factor.The qualitative analysis and optimization verification was carried out from the geometric structure.The properties of the working fluid mainly include surface tension and viscosity.The research results show that the greater the surface tension,the smaller the spray angle;the greater the viscosity,the larger the spray angle.Surface tension and viscosity have no significant effect on other characteristics such as discharge coefficient and liquid sheet velocity.The characteristics of liquid sheet rupture and ligament broken are described,and it is found that the turbulence intensity is greater in the region of liquid sheet broken.The broken length is defined,and it is concluded that there is a linear relationship between the broken length and the 1/4th power of the surface tension.In addition,the influence of insoluble particles on the performance of the nozzle is considered.When the mass fraction of insoluble matter increases,the nozzle discharge coefficient decreases,the liquid sheet velocity decreases,and the spray angle does not change significantly,but the liquid sheet breakup is more violent.