An-Najah Blogs :: An-Najah Blogs :: en-us Sun, 24 Sep 2017 01:46:01 IST Sun, 24 Sep 2017 01:46:01 IST Development of New Type of Gas Absorber, Industrial Applications ArticlesThe performance of a new type of gas absorber was investigated Laboratory absorption experiments on different absorption systems such as ethylthiol acetonewater ethanolwater methylene chloridefesto oil and H2SNaOH were carried out under reduced air pressure The absorption rate was investigated as a function of geometrical parameters and construction materials The possibility of installating more than one gas absorber on the same absorption tank was investigated as well It has been applied successfully in industry In general this unit improves the performance of existing absorption columns by absorbing 2530 of the released gases or vapors and this value may be higher in the case of chemisorption which leads to higher environmental protection Moreover a jet absorber has a simple structure small size with low investment and operation costs; it is suggested that it is used to cope with any sudden increase of gas or vapor emissionHydrodynamics and mass transfer of textile vibrating-valve trays ArticlesNew types of vibrating valve trays with textile valves were investigated to determine their optimal construction Hydrodynamic and mass transfer measurements were carried out in a pilot plant with different vibrating valve and conventional valve trays under identical experimental conditions The total tray pressure drop column efficiency volumetric mass transfer coefficient and pressure drop per theoretical tray were measured and compared The high mass transfer rate low investment and operating costs corrosion and heat resistance make the vibrating valve trays attractive for gas absorption and air cleaning in environmental protectionHydrodynamic characteristics of Nutter valve trays, new correlations ArticlesHydrodynamic parameters were measured in a Nutter valve tray simulation column The clear liquid height was determined in different operating regimes foam mixed and spray regimes and new formulas were developed as functions of weir height and flow parameter New correlations were developed as functions of geometrical and operating parameters for the total liquid hold-up and the relative froth densityInfluence of weeping on mass transfer rate of different plates : Distillation ArticlesThe influence of weeping on the mass transfer of different industrial plates was investigated in a 400 mm inside diameter column equipped with 4 plates The absorption of acetone from air to tap water was measured on vibrating valve Nutter valve Glitch valve sieve and turbogrid plates with varied weir heights The weeping was determined by a direct method The tray efficiency of the investigated plates decreased 1-5 with the increase of weeping rate while it decreased 10-25 with the increase of weir height Mass transfer characteristics of the above plates namely recovery efficiency E volumetric mass transfer coefficient KGa and pressure drop related to one theoretical plate pNth were measured and comparedInfluence of surface tension on pressure drop of sieve plates ArticlesA new general expression is developed for the hydrodynamic design of sieve plates namely for the calculation of total pressure drop and its components The division of total pressure drop into part pressure drops is theoretically based on the momentum theory and fundamental laws of fluid flow Applying and developing the results of Haq3 and Davy and Haselden it was established: 1 The partial pressure drops except that of wet plate pressure drop are practically independent of surface tension liquid density and viscosity 2 The wet plate pressure drop is a parabolic function of gas velocity It is practically independent of liquid density and viscosity in wide range but strongly depends on surface tension In conclusion a general expression is presented for total pressure drop of sieve plates which is theoretically established valid in all the three foaming regimes and expresses the influence of surface tensionClear liquid height on sieve plates in the froth, mixed and spray regimes ArticlesThe clear liquid height on sieve plates has been measured in a hydraulic simulation column Experimental work and investigation of published data show that three different foaming regimes have to be distinguished as Chen recognised and the hole diameter has an influence on the clear liquid height as Dhulesia proposed The Hofhuis-Zuiderweg correlation has been modified to describe the clear liquid height in the froth mixed and spray regimes respectively Different formulae have been developed for each of the foaming regimes Two new parameters have been introduced: the hole diameter and the free cross sectionSimulation Of Carbon Dioxide Absorption Into Sodium Hydroxide Solution In Nutter-Valve Plate Column ArticlesThe profiles of temperature concentrations and hydrodynamic parameters along the column height were simulated for the absorption of carbon dioxide into a sodium hydroxide solution of total concentration up to 44 N in a Nutter-valve plate column The influence of the CO2 concentration in the gas phase on the temperature and concentration profiles was estimated The results of simulation were compared to an experiment for the case of low concentration of CO2 in the gas phase ~1 and low concentration of Na OH solution ~1 N Comparison of the Nutter-valve and sieve plate columns is also presented