Impeller Design

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 8127 Experts worldwide ranked by ideXlab platform

Chirangano Mangwandi - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Impeller Design on Homogeneity, Size and Strength of Pharmaceutical Granules produced by High Shear Wet Granulation
    Particuology, 2015
    Co-Authors: Zakaria A. Mirza, Jiangtao Liu, Yoann Glocheux, Ahmad B. Albadarin, Gavin Walker, Chirangano Mangwandi
    Abstract:

    Abstract Small mixer Impeller Design is not tailored for granulation because Impellers are intended for a wide range of processes. The aim of this research was to evaluate the performances of several Impellers to provide guidance on the selection and Design for the purposes of granulation. Lactose granules were produced using wet granulation with water as a binder. A Kenwood KM070 mixer was used as a standard apparatus and five Impeller Designs with different shapes and surface areas were used. The efficacy of granulate formation was measured by adding an optically sensitive tracer to determine variations in active ingredient content across random samples of granules from the same size classes. It was found that Impeller Design influenced the homogeneity of the granules and therefore can affect final product performance. The variation in active ingredient content across granules of differing size was also investigated. The results show that small granules were more potent than larger granules.

Yukihiko Nosé - One of the best experts on this subject based on the ideXlab platform.

  • the next generation baylor c gyro pump antithrombogenic free Impeller Design for long term centrifugal vad
    Artificial Organs, 1994
    Co-Authors: M Yasuhisa D Ohara, Yukihiko Nosé
    Abstract:

    Abstract: The new generation centrifugal blood pump, the C2 Gyro Pump “Free Impeller Model” specifically Designed for long-term ventricular assistance and a bridge to transplantation, has been developed. In the free Impeller Design, the Impeller was completely freed from mechanical tethers by eliminating the shaft. This unique Design allowed the incorporation of a center-penetrating hole in the Impeller, called the center conduit, which accelerates the secondary blood flow from the bottom to the top of the Impeller. During in vitro performance tests, two characteristic Impeller motions, called floating mode and wandering rotational axis, were observed. In the floating mode, the Impeller seemed to be floating without touching the pump casing and resulted in the idea of no bearing contact. Also, the rotational axis of the Impeller exhibited a small circular motion and illustrated the idea of no stationary area in the blood path. These three characteristics are expected to be advantageous for antithrombogenesity and low hemolysis which are essential for a long-term centrifugal VAD.

  • The Next Generation Baylor C‐Gyro Pump: Antithrombogenic “Free ImpellerDesign for Long‐Term Centrifugal VAD
    Artificial organs, 1994
    Co-Authors: Yasuhisa Ohara, Yukihiko Nosé
    Abstract:

    Abstract: The new generation centrifugal blood pump, the C2 Gyro Pump “Free Impeller Model” specifically Designed for long-term ventricular assistance and a bridge to transplantation, has been developed. In the free Impeller Design, the Impeller was completely freed from mechanical tethers by eliminating the shaft. This unique Design allowed the incorporation of a center-penetrating hole in the Impeller, called the center conduit, which accelerates the secondary blood flow from the bottom to the top of the Impeller. During in vitro performance tests, two characteristic Impeller motions, called floating mode and wandering rotational axis, were observed. In the floating mode, the Impeller seemed to be floating without touching the pump casing and resulted in the idea of no bearing contact. Also, the rotational axis of the Impeller exhibited a small circular motion and illustrated the idea of no stationary area in the blood path. These three characteristics are expected to be advantageous for antithrombogenesity and low hemolysis which are essential for a long-term centrifugal VAD.

J L Barredo - One of the best experts on this subject based on the ideXlab platform.

  • numerical investigation of the effect of Impeller Design parameters on the performance of a multiphase baffle stirred reactor
    Chemical Engineering & Technology, 2011
    Co-Authors: Alfredo Iranzo, Ruben Barbero, Jeronimo Domingo, Daniel Cuadra, J Costa, J F Martin, R V Ullan, J L Barredo
    Abstract:

    The turbulent gas-liquid flow field in an industrial 100-m3 stirred tank was calculated by using computational fluid dynamics based on the finite-volume method. Turbulent effects were modeled with the shear stress transport model, and gas-liquid bubbly flow was modeled with the Eulerian-Eulerian approach using the Grace correlation for the drag force interphase momentum transfer. The relative motion between the rotating Impeller and the stationary baffled tank was considered by using a multiple frames of reference algorithm. The effects of Rushton and pitched-blade Impeller Design parameters such as blade geometry, location, and pumping direction on the mixing performance were investigated. It was found that a combination of Rushton turbines with up-pumping pitched-blade turbines provides the best mixing performance in terms of gas holdup and interfacial area density. The approach outlined in this work is useful for performance optimization of biotechnology reactors, as typically found in fermentation processes.

  • Numerical Investigation of the Effect of Impeller Design Parameters on the Performance of a Multiphase Baffle‐Stirred Reactor
    Chemical Engineering & Technology, 2011
    Co-Authors: Alfredo Iranzo, Ruben Barbero, Jeronimo Domingo, Daniel Cuadra, J Costa, J F Martin, R V Ullan, J L Barredo
    Abstract:

    The turbulent gas-liquid flow field in an industrial 100-m3 stirred tank was calculated by using computational fluid dynamics based on the finite-volume method. Turbulent effects were modeled with the shear stress transport model, and gas-liquid bubbly flow was modeled with the Eulerian-Eulerian approach using the Grace correlation for the drag force interphase momentum transfer. The relative motion between the rotating Impeller and the stationary baffled tank was considered by using a multiple frames of reference algorithm. The effects of Rushton and pitched-blade Impeller Design parameters such as blade geometry, location, and pumping direction on the mixing performance were investigated. It was found that a combination of Rushton turbines with up-pumping pitched-blade turbines provides the best mixing performance in terms of gas holdup and interfacial area density. The approach outlined in this work is useful for performance optimization of biotechnology reactors, as typically found in fermentation processes.

Uwe Schmidt - One of the best experts on this subject based on the ideXlab platform.

  • Impact of Impeller Design on high-shear wet granulation
    Powder Technology, 2016
    Co-Authors: Matthias Börner, Marc Michaelis, Eva Siegmann, Charles Radeke, Uwe Schmidt
    Abstract:

    Abstract In recent decades, three-blade Impellers have been well-established in pharmaceutical high-shear granulation. However, three-blade Impellers often require high rotation speeds to initiate product circulation and to provide proper granulation performance. With high rotation speeds much energy is introduced, which is indeed favourable for granule consolidation, however it comes with undesirable thermal stressing and increased granule breakage rates. In order to improve the mixing and granulation behaviour for a more robust process, a new Impeller Design has been developed that works at lower rotation speeds. The Impeller consists of two blades with elongated side wings. In this work, the performance of both Impeller Designs is intensively studied. Firstly, the mixing behaviour is experimentally investigated in a laboratory mixer (10 L in volume) and at production scale (600 L). The mixing homogeneity of coloured sugar pellets is examined by the digital image analysis (DIA) for several Impeller rotation speeds. In a second study, discrete element method (DEM) simulations are employed to obtain shear forces and force distributions at a single-particle scale. The third study is the comparison of granulation performance using a placebo formulation in the frame of a full factorial Design of experiments (DoEs). The mixing investigations show that the two-blade Impeller has great potential for scale-up. The DEM simulation confirms that both Impeller types investigated apply almost the same shear forces on particles. The granulation performance in the DoE is proven to be better for the two-blade Impeller. Larger drive torque is measured, product temperature increases significantly less with reduced thermal stressing, and larger granules are produced. Additionally, particle growth behaviour is more robust as it depends only on the amount of liquid added and is unaffected by the Impeller's rotation speed.

Stephane Delaunay - One of the best experts on this subject based on the ideXlab platform.

  • CFD numerical simulation of particle suspension and hydromechanical stress in various Designs of multi-stage bioleaching reactors
    Hydrometallurgy, 2020
    Co-Authors: Jonathan Chéron, Stephane Delaunay, Céline Loubière, Anne-gwenaëlle Guezennec, Eric Olmos
    Abstract:

    Abstract The performance of bioleaching stirred tank reactors (STR) is related to the homogeneity of biomass, substrates and dissolved gases. This work was focused on the characterization of the Impeller Design on bioreactor hydrodynamics and, more specifically on power, mixing efficiency and particle stress. Few studies addressed the issue of the impact of the Impeller Design on these, especially for multi-stage bioreactors which are the most commonly used at the industrial scale. To fill this lack, a two-stage solid-liquid computational fluid dynamics (CFD) model was simulated on more than 50 conditions to assess power consumption, dissipated power, suspension quality and particle stress. A dual Impeller configuration was chosen using Rushton turbines, R600, Hydrofoil, Elephant Ear and HTPG Impellers. Grinded pyrite-rich materials (average particles size: 80 μm) were considered as the solid phase at 3 different solid concentrations (10, 18 and 26% w/w). Considering the Impeller power number (Np), the configuration with an axial Impeller consumed less energy than a radial Impeller in concordance with literature data. The results show that the Impeller Design had few to no effect on mixing efficiency considering a given power dissipation per unit volume. Independently on the Impeller used, unique relationships were found between particle stress and mixing efficiency. This study gives new insights for reactor Design and scaling of bioleaching stirred tank reactor and more specifically on the reduction of shear stress for the attached bacterial communities.

  • impact of shear stress and Impeller Design on the production of biogas in anaerobic digesters
    Bioresource Technology, 2017
    Co-Authors: Aline Lebranchu, Stephane Delaunay, Philippe Marchal, Fabrice Blanchard, Stephane Pacaud, Michel Fick
    Abstract:

    Today, intensification of anaerobic digestion is still a scientific and technical challenge. The present study proposed combined experimental and computational fluid dynamics simulations to characterize the impact of shear stress and Impeller Design on the biogas production after sequential additions of substrate. Liquid phase (cattle manure digestate) rheological law was experimentally determined and input in numerical simulations. The results showed that the original use of a double helical ribbon in digester allowed a significantly faster dispersion of fresh substrate than the use of a classical Rushton turbine, leading to a 50% higher methane production rate. However, with both Impellers, too high agitation rates entailed a clear slow-down of production rate and a decrease in CH4 content. To avoid this loss of productivity, it was shown that the maximal value of shear stress, determined by numerical simulations, was a consistent parameter to set the upper agitation conditions in digesters.