Research And Application On Performance Of Composite Directed Valve Trays

Directed valve trays were used in industrial column widely because of their excellent characteristics in hydraulics and mass transfer. Based on rectangular directed valve plate, two types of composite directed valve plate were researched in this paper. One was refer to as CDV plate which was composed of valves and sieves. And sieve was in between two directed valves. Then adding guide holes in the liquid entrance area of the CDV plate got the other plate named CDV-GH plate. The experiments were carried out in the 1500 mm×450 mm rectangular column. The hydraulics data of two composite plates was got by air-water system, and the mass transfer efficiencies were measured by air-water-carbon dioxide system.The comparison among experimental results turned out that compared with CDV, CDV-GH plate had better hydraulics and mass transfer characteristics under the same experimental conditions of large liquid flow intensity and valve hole kinetic energy factor. And the hydraulic performance of the CDV-GH was measured in this paper, including the liquid level gradient, the entrainment rate, the pressure drop and the leakage point hole velocity. Then the corresponding correlation equations were obtained by MATLAB software in order to apply CDV-GH plate in the future. In addition, CDV-GH plate had been used in a industrial case, which was modification of a fractionate tower in gasoline and diesel oil hydrogenation refining fractionation column. There was a wonderful consequence of the modification that the pressure drop of trays decreases by 10%, the content of sulfur in the refined diesel oil was reduced from 110μg/g to 10 μg/g, and the nitrogen content decreased from 97 μg/g to 10 μg/g. Therefore, the expansion of emission reduction effect was obvious.