The Gyro centrifugal pump, developed as a totally implantable artificial heart, was designed with a free impeller in which the rotational shaft (male bearing) of the impeller was completely separated from the female bearing. For this type of pump, it is very important to keep the proper magnet balance (impeller-magnet and actuator-magnet balance) to prevent thrombus formation or bearing wear. W...

This paper tries to determine an optimum condition for the flotation operation of the Alborz-Sharghi coal washing plant. For this purpose, a series of comprehensive experiments have been conducted on representative samples from feed of the flotation system of the plant. Four operational variables such as the collector dosage (Fuel oil), the frother dosages (MIBC), the pulp density percent and t...

Axial-flow pumps, in addition to providing high anti-cavitation properties, must have anti-erosion properties ensure the required lifetime of pump. Erosion damage surfaces occurs when net positive suction head (NPSH) significantly exceeds its critical value. The object study this article is axial-flow pump with a specific speed 600 two alternatives: № 1 and 2. By analysis flow impeller blade sy...

multiphase impeller stirred tank reactors enhance mixing of reacting species used in a variety of chemical industries. these reactors have been studied based on computational fluid dynamics (cfd) that can be used in the analysis, design and scale up of these reactors. most of the researches done in this area are limited to single phase reactors, and a few remaining two phase flow investigations...

A nite element based method has been developed for computing time-averaged uid-induced radial excitation forces and rotor dynamic forces on a two-dimensional centrifugal impeller rotating and whirling in a volute casing. In this method potential ow theory is used, which implies the assumption of irrotational inviscid ow. In comparison with other analyses of uid-induced impeller forces, two main...

The production of Schizophyllan by Schizophyllum commune and Scleroglucan by Sclerotium rolfsii is growth associated. Shear stress as a result of the impeller type and rotation speed as well as an optimum but not maximum oxygen supply are the key factors for enhanced production. Batch cultivations resulted maximum yields of 13 g L for both ß-glucans. In oxygen limited chemostats with biomass fe...

Flow through mixed flow compressor stage was evaluated theoretically to understand internal flow behaviour. Various shroud configurations in terms of clearance has been considered to see the effect of clearance on compressor performance. The blade to blade relative flow variation from impeller inlet to outlet was evaluated through theoretical analysis. A 3D viscous commercial code Fluent was us...

Despite the progresses in developing pulsatile impeller pump and impeller total heart, as well as in applying streamlined impeller vanes, the best results in application of artificial heart pumps have been achieved by nonpulsatile univentricular assist pump with straight impeller vanes until now. It seems all efforts and successes have been done in vain because artificial heart rejects Hi-Tech!...

Enzymatic synthesis of palm oil esters (POE) was carried out via alcoholysis of palm oil (PO) and oleyl alcohol (OA) catalyzed by Lipozyme TL IM. The optimum reaction conditions were: temperature: 60 °C; enzyme load: 24.7 wt%; substrate ratio: 1:3 (PO/OA), impeller speed: 275 rpm and reaction time: 3 h. At the optimum condition, the conversion of POE was 79.54%. Reusability study showed that Li...