BACKGROUND When scaling up lignocellulose-based ethanol production, the desire to increase the final ethanol titer after fermentation can introduce problems. A high concentration of water-insoluble solids (WIS) is needed in the enzymatic hydrolysis step, resulting in increased viscosity, which can cause mass and heat transfer problems because of poor mixing of the material. In the present study...

Gas holdup is one of the most important hydrodynamic parameters needed for reliable design, performance estimation, and scale-up of stirred tank reactors (STRs). In the present work, local gas holdup is measured in an acrylic stirred tank reactor equipped with a Rushton impeller using X-ray computed tomography (CT) for many different operating conditions. Power consumption for different operati...

The inducer is a very small booster pump, lifting the suction pressure to a sufficient level for the main conventional impeller. By adding the inducer to high speed centrifugal pumps, NPSHr can be reduced to a great extent. Liquid with high gas content can be pumped successfully with inducer equipped pumps. Even low NPSHr allows a smaller, higher speed low horsepower pump, saving energy and cap...

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...

The most commonly used hard limitation for pump suction specific speed is 11,000 (US units). This hard limit grew out of the recommendations from a 1982 reliability study by J.L. Hallam (Hallam 1982). Concomitant testing of the vibration performance of an OH2 4x6-11 pump was made with impellers designed for different suction specific speeds (Lobanoff and Ross 1985). This study showed that all t...

Along with the developments of high-speed and highperformance turbomachines, there has been increasing occurrence of rotational speeds higher than the first critical speed. Under these circumstances, turbomachines may suffer from severe vibration and rotor whirl caused by fluid-dynamic forces. As possible causes of whirling instabilities, fluid forces on journal bearings and seals are well know...

During the operation of a high-speed shear wet granulator, rotation granulation components leads to emergence phenomenon particle breakage, which results in changes size. To simulate breakage process pharmaceutical powder agglomerates Hertz–Mindlin with bonding contact model was designed this study. The effects impeller speed, chopper and time on were then studied. show that formed by particles...

The analysis sensitivity of strength, rigid and dynamic characteristics the console rotor to variation design parameters in paper describes speed rotation shaft, material impeller vary. dependences radial axial displacements on angular velocities modulus elasticity are established. For objects type rotary systems with a cantilever arrangement impeller, not one, but set criteria has been introdu...

The purposes of inlet and outlet devices for rotary blood pumps, including inducers and diffusers for axial pumps, inlet and exit volutes for centrifugal pumps, and inlet and outlet cannulas, are to guide the blood into the impeller, where the blood is accelerated, and to convert the high kinetic energy into pressure after the impeller discharge, respectively. The designs of the inlet and outle...