Although the mathematics that define the operation of an impeller can be complex (it is the stuff of Bernoulli and Euler), its purpose is straight forward. An impeller is designed to impart energy to a fluid so that it will flow or, if it is already flowing, undergo some increase in its elevation or pressure. It accomplishes this by increasing the fluid’s velocity as it travels through its vane...

Lipase-catalyzed production of palm esters by alcoholysis of palm oil with oleyl alcohol in n-hexane was performed in 2L stirred-tank reactor (STR). Investigation on the performance of reactor operation was carried out in batch mode STR with single impeller mounted on the centrally located shaft. Rushton turbine (RT) impellers provide the highest reaction yield (95.8%) at lower agitation speed ...

In the present work, the effects of dual impeller configurations comprising of Rushton turbine (RT) and Concave-bladed disk turbine (CD-6) on the oxygen transfer profile and fermentation performance of kojic acid production by Aspergillus flavus Link 44-1 was investigated. Batch cultivations of A. flavus Link 44-1 were performed in 2 L stirred tank bioreactor. The fermentations were conducted u...

The changes in chemical production processes, in particular the shift from chemical production to biotechnology, puts more emphasis on shear rate control of mixing devices. At the same time, mixing devices should be highly optimized with respect to power consumption, both for economical reasons and due to the prevention of additional heat-up of the mixing process. In addition, most biotechnolog...

Axial pumps have a wide range of applications, and cavitation is one of the main causes of there performance degradation. So, the present study investigates experimentally and numerically the performance of cavitating axial pumps. In this study a three-dimensional Navier-Stokes code was used (CFDRC, 2004) to model the two-phase flow field around a four blades axial pump. The governing equations...

an experimental study has been conducted on the hydrodynamics of a stage mixer-settler to obtain an appropriate design. in this paper several tests was performed to investigate full factorial design of experiments. since each test was repeated seven times, the repeatability of the test was confirmed (p=1 bar and t=25 °c). sauter diameter was determined by photographing both the mixer and settle...

The experimental investigation of a centrifugal compresso r is carried out to improve HCFC123 compression performance. A CFCll c ompressor applying HCFC123 shows a lowered adiabatic head rise, efficie ncy, and volume flow. Another CFC!l compressor with HCFC123 and a modifie d impeller shows a result comparable to the CFCll compression case. A tan dem impeller is designed to cover the volume flo...

In this paper, the reasons of damage water pumps parts of the air compressor cooling system were studied. To reach this goal, the works like preparing metallographic samples, evaluation of structure, investigation of mechanical properties, the alloy parts detection and chemical analysis of deposit and corrosion products collected from the parts were performed. According to studies and results o...

a laboratory stirred tank bioreactor with six single and dual-impeller configurations was tested to obtain the optimum operating conditions for future biological processes. six impeller combinations consisting of three basic impeller types, namely rushton turbine (rt), pitched 4blade (p4b) and pitched 2blade (p2b) downward flow were investigated in 1.77 l bioreactor working volume. power consum...

Impeller stirred tanks (STR) are commonly used in the chemical processing industries (CPI) for a variety of mixing and blending technologies. In the present research, a numerical study of flow and mixing inside turbulently agitated tanks were carried out. An efficient solution algorithm was developed to solve turbulent flow inside stirred tanks where the boundary conditions for moving impeller ...