| Based on the current national implementation of SO2 ultra-low emission control in flue gas,this paper summarizes the wet flue gas desulfurization technology and desulfurization equipment,and points out that sodium alkali method has the advantages of fast reaction rate,high desulfurization efficiency and low liquid gas ratio.Compared with the limestone-gypsum desulfurization technology commonly used in our country at present,the sodium alkali method avoids the means of increasing the number of spraying layers or series tower equipment,especially for the transformation of old factories,which is beneficial to save the floor area and reduce the investment cost,and has certain potential in realizing the wide application of industrialization.However,in order to achieve deep desulfurization and ultra-low emission,it is necessary to introduce a new and efficient desulfurization device to solve the problems of slow gas mass transmission rate and large equipment volume,so as to give full play to its greatest advantages and further decrease alkali consumption.Therefore,by optimizing the process conditions and exploring the influence of the structure and height of packing layer on the desulfurization rate and mass transfer performance,this paper shows that the cross-flow rotating bed of multi-layer packing can achieve ultra-low emission.It also provides a reference for industrial application and the structure design of cross-flow rotating packed bed,and has important practical significance.With the cross-flow rotating bed of multi-layer packing as the desulfurization absorption equipment,the effect of sodium ion concentration[Na+],inlet SO2 concentration Cin,high gravity factor?,spray density q and empty bed gas velocity u on desulfurization performance was investigated by using the regenerated desulfurization liquid as absorbent,and the suitable technological conditions were obtained.Experimental results showed that under the operating conditions of[Na+]=0.61.0 mol/L,?=5586,q=46 m3/?m2·h?,u=1.72.0 m/s and Cin?4000mg/m3,the outlet SO2 concentration is less than 35 mg/m3.When the concentration of imported SO2 is 1714 mg/m3,the outlet concentration is only about 14 mg/m3,and the desulfurization rate is over 99%,achieving deep purification.In the structure of cross-flow rotating bed of multi-layer packing,the effects of packing stator,packing distribution and axial height of packing rotor on desulfurization rate and mass transfer performance were investigated.Experimental results show that both?and kyae increase with the increase of?,u and q.Under the same operating conditions,?of the packing stator increases by 5%15%and kyae increases by 0.61 times compared with that of the non-packing stator,which indicates that the packing stator can effectively enhance the gas film mass transfer process.When the packing distribution is changed,?and kyae increase with the increase of??q?u.And the packing rotor with a height of 100 mm is divided into upper and lower heights of50 mm,?increases by about 10%,and kyae increases by 0.2 to 0.4 times.Effect of packing height on desulfurization efficiency and mass transfer performance was studied.When the packing rotor height was 100 mm,?increased by 10%30%,while kyae decreased by 0.10.4times.Experimental results show that the end effect area of cross-flow rotating packed bed is located at the bottom of the packed bed in the gas film control system.In this paper,through the optimization of process conditions and the improvement of the structure of rotating packed bed,the efficient flue gas desulfurization is realized,and the ultra-low emission standard is reached.It provides a reference for further structural improvement of the rotating packed bed,so as to give full play to the potential of enhanced mass transfer. |
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