February 2013, Volume 4, No.1 International Journal of Chemical and Environmental Engineering Study the Effect Of Impeller Design On Power Consumption Tazien Rashid*, Syed Zahoor-ul-Hassan Rizvi, Shahid Raza Malik Institute of Engineering and Fertilizer Research Jaranwala Road Faisalabad, Punjab, Pakistan *Corresponding author E-mail:tazien@iefr.edu.pk Abstract: This paper emphasizes on the mass transfer studies that have been carried out in a 370 mm diameter and length of 450 mm Perspex cylindrical vessel attached with a DC motor that can operate on different RPM effect of impeller type on power consumption was calculated for impellers. Flow visualization technique was used to study the hydrodynamic in the cylindrical vessel for kerosene- water system for four types of impellers. Rhodamine-B (water soluble dye) was used to identify the flow patterns in the extraction and separation zones of the contactor. Keywords: extraction; separation; chromatography; hydraulic power; batch mode; Hydrodynamic 1. Introduction Liquid-liquid extraction is an important purification enrichment separation method used in the chemical, biochemical, petrochemical, pharmaceutical and food industries. Despite the increasingly extensive applications of liquid extraction, greater versatility, and the extensive amount of research that has been done, it is nevertheless a relatively immature unit operation. There are many problems associated with traditional liquid-liquid extraction equipment like phase separation, solvent loss, emulsion formation, loading and flooding in conventional column contactors and mixer settlers. Moreover, traditional units also have high power consumption and are maintenance intensive due to their interior moving parts. Improving the contacting and separation performance has always been a challenge for technologists involved in developing liquid-liquid extraction equipment [16–19]. Previous studies on the impeller design have shown that the power number is sensitive to the details of impeller geometry, and in particular to the blade thickness, but is independent of the impeller diameter to tank diameter ratio. But latter on it is studied that the power number is independent of blade thickness, but dependent on the impeller to tank diameter ratio. This is exactly the opposite result to one another. In the present research work it is studied that power number is dependent on impeller geometry as well as impeller to tank diameter ratio. Physical explanations are given for the dependencies and differences in behavior between the two impellers. for the angled blades power consumption is dominated by form drag, so details of the blade geometry have a significant impact (30%) on the power number. for the straight blade impeller, form drag is not as important, but the impeller interacts strongly with the proximity of the tank walls, so changes in the position of the impeller in the tank can have a significant impact on the power number in industrial mixing applications, the power consumption per unit volume of fluid is used extensively for scale-up, scale-down and design. in spite of its widespread use, the dependence of power consumption on impeller and tank geometry is dependent only in the most general terms. this is partly due to the difficulty of obtaining accurate torque measurements on the small scale, and partly due to the predictive limitations of drag theory. A significant limitation of this interesting theoretical approach is the assumption that there is no interaction between the impeller and the tank walls. 2. Materials and Method: The apparatus used in the experimental arrangement comprised of the following items: 1. Cylindrical Vessel Apparatus 2. Impellers 3. Glass Beakers 4. Variable Speed Controller (Precise Power Strength Mixer) Flow visualization studies and quantitative measurements were performed on experimental models which were mounted in a clear cylindrical vessel. This tank had a dia of 370 mm and height of 450 mm three baffles were used having width of 55 mm and length of 430 mm, equally