Abstract: Longitudinal eddy diffusivities of liquid on sieve plates have been determined experimentally with fiber optic technique. The experiments were carried out in a rectangular simulator with air-water system. Two sieve plates were used: one with 5mm diameter holes and 7% free area of tray, the other 10mm and 9%. The weir heights were ranged from 10 to 50mm, as conventionally used nowadays. The stimulus-response technique used was first proposed by Aris and later corrected by Bischoff. In the experimental work the tracer, here aqueous rhoda-mine-B solution being used, was not injected upstream inside the boundary of the active plate area, but upstream outside the boundary of that, i. e. injected into the liquid in the upstream downcomer, and the tracer concentrations were measured at two sections along the flow path. Consequently, the problem of a perfect delta function of tracer into the flowing system and the difficulty of uniformly distributing tracer along the section of injection were thus avoided. Since the measuring probes were quite small in size(about 2mm in diameter) and the tracer was not injected into the liquid on the plate, the flow pattern on plate would not be disturbed and the results should be more reliable than those reported previously in the literature. The data have been correlated as follows: ( 1 ) For Sieve plate with 5mm holesD0.5e= 0.0339 - 6.27 × 10-4/hw+ 0.0165FT + 2.57 × 10-3L ( 2 ) For Sieve plate with 10mm holes D0.5e=0.0243 - 6.40 × 10-4hw+ 0.0121FT+ 3.77× 10-3L And a generalized correlation for hole diameters from 5 to 10mm is: D0.5e = 0.0155 -6.31 × 10-4hw + 0.0275FT + 3.13 × 10-3L where De= Eddy diffusivity, m2/s FT=Vapor flow parameter based on total column sectional area, (m/s)(kg/m3)1/2 hw - Height of weir above plate floor, mm. L = Liquid flow rate, m3/hr per m length of weir. By using the eddy diffusion model and the eddy diffusivity found by the above correlations, the predicted Murphree efficiency agrees well with the actually determined one of a well known precise experiment of Foss et al.

摘要： 本研究采用纤维光学技术及以任意方式注入示踪剂、两点检测之激励-响应手段,实测了普通筛板和大孔径筛板的液相涡流扩散系数.通过对试验数据的回归分析,在较宽的操作条件范围内,得到了涡流扩散系数与堰高、液流强度及空塔气体动能因子的关联式,并发现普通筛板和大孔径筛板可用同一关联式很好地关联.本文关联式所预测的板效率与实测的板效率相比相当符合.