According to tradition, permanent maglev cannot achieve stable equilibrium. The authors have developed, to the contrary, two stable permanent maglev impeller blood pumps. The first pump is an axially driven uni-ventricular assist pump, in which the rotor with impeller is radially supported by two passive magnetic bearings, but has one point contact with the stator axially at standstill. As the ...

This paper describes the shape optimization of impeller blades for a anti-heeling bidirectional axial flow pump used in ships. In general, a bidirectional axial pump has an efficiency much lower than the classical unidirectional pump because of the symmetry of the blade type. In this paper, by focusing on a pump impeller, the shape of blades is redesigned to reach a higher efficiency in a bidir...

To finalize the design of the next generation of the HeartQuest left ventricular assist device, a suitable impeller had to be designed and tested. The new prototype was based on calculations and test results of previous designs, but required several changes to decrease the size. For most pump designs, this is a simple matter of altering impeller geometry and rotational speed to achieve the desi...

Sewage water pumps very often are equipped with impellers featuring a small number of blades which therefore provide big cross sections of the flow channel. Single-blade impellers comprise the smallest possible number of blades and are known as non-clogging pumps. But severe disadvantages occur during operation, because the timevariant flow in such pumps results in periodic unsteady flow forces...

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...