STUDIES ON FLOODING POINT AND HOLD-UP IN A SOLVENT EXTRACTION COLUMN WITH RECIPROCATING SIEVE PLATES

The flooding point and hold-up of the dispersed phase in an extraction column with reciprocating-sieve plates of 32 mm inside diameter and 1960 mm effective column height have been investigated under thefollowing conditions:Percent perforation of the plates 40%,53.5% and 63.7%,diameters of perforatedholes 7.8,9.0 and 9.8 mm,and distances between plates 20 and 40 mm respectively.Experiments werecarried out with three different liquid-liquid systems covering a rather wide range of physical properties.The relative velocity of the two phases passing through the perforations of the plates is consideredin the present work to be related to the work done by the oscillating plates in the column on unit massof liquid in unit time.Therefore the flooding velocity and hold-up in extraction column with reci-procating sieve plates should be related to A~2F~3 instead of AF as reported before.Equations weredeveloped to correlate the experimental data of flooding point and hold-up respectively.     

振动筛板萃取塔的液泛点和塔藏量的研究

在塔径32mm,高1960mm的振动筛板萃取塔中,用叔胺N_(235)-TBP-煤油/水等三个无传质体系,进行了液泛点和塔藏量的研究.作者认为两相流过筛孔的实际相对速度,与塔板在单位时间内对单位质量液体所做的功有关,并与体系物性及板间距相关.由于这种想法,建议用A~2F~3代替常用的AF,可以较好地关联本实验数据,和较简明地反映各参数对液泛点和塔藏量的影响,得到了一个新关联式.研究结果指出:①振幅和频率对液泛点和塔藏量的影响是不同的;②分散相的选择无显著影响,③塔板开孔率和板间距是肯定有影响的.实验的振动强度及体系物性参数的范围较宽,塔板开孔率大,板间距小,并采用金属萃取广泛应用的叔胺及二(2-乙基己基)磷酸苹取剂以及煤油稀释后作为有机相.因此,本工作对推广这种塔于金属萃取将有一定的促进作用.     

多层筛板并流鼓泡塔中液体轴向混合的研究

本文检验了级内完全混合-级间有返混的模型对于多层筛板鼓泡塔中液体轴合混合的适用性。在空气-水系统中,用示踪剂研究了级间返混系数与设备参数、操作参数间的关系,对返混机理进行了考察,得到了返混系数与主要设备参数、操作参数间的关系式。实验中发现,气体分布板附近四层的返混系数受到气体分布板即端效应的影响。因此只有第四层以上的返混系数才逐层相等。