The Experts below are selected from a list of 2220 Experts worldwide ranked by ideXlab platform

B C Meikap - One of the best experts on this subject based on the ideXlab platform.

  • characteristics of Minimum Fluidization Velocity for magnetite powder used in an air dense medium fluidized bed for coal beneficiation
    Particle & Particle Systems Characterization, 2012
    Co-Authors: S Mohanta, Anil Babu Daram, Sudipto Chakraborty, B C Meikap
    Abstract:

    Accurate determination of Minimum Fluidization Velocity of medium particle is essential for proper designing and operation of an Air Dense Medium Fluidized Bed Separator for coal beneficiation. Significantly different values of Minimum Fluidization Velocity have been obtained from different available correlations. So, it is necessary to develop a suitable correlation for this specific purpose. In this study, the Minimum Fluidization velocities of different size magnetite powders are investigated in a 15 cm diameter fluidized bed. Three correlations are derived from the fundamental principles for the theoretical prediction of these Minimum Fluidization velocities. The adequacy and reliability of each of these correlations is tested by adopting a statistical analysis approach and the most suitable correlation is selected. The predictive capability of this selected correlation is verified by using the data available in the literature. The results show that this new correlation is in very well agreement with these experimental data and shown to be applicable for practical purpose. Moreover, this study reveals that the correlation developed from the basic particle properties and bed characteristics can predict more accurate results.

Jesse Zhu - One of the best experts on this subject based on the ideXlab platform.

  • prediction of dense phase voidage for group c fluidized bed reactor
    Chemical Engineering Journal, 2020
    Co-Authors: Yandaizi Zhou, Jesse Zhu
    Abstract:

    Abstract Group C+ fluidized bed reactor exhibited better reactor performance than conventional fluidized bed reactors, due to the larger specific surface area of the catalysts and the more homogeneous Fluidization, especially the extraordinary dense phase expansion which contributes to higher gas–solid contact efficiency. As a critical parameter affecting the reactor performance, the dense phase voidage (ed) was thoroughly characterized and general correlations for predicting ed were derived based on both Richardson-Zaki and Kozeny-Carman approaches. In addition, a new method for predicting the Minimum Fluidization Velocity of Group C+ particles with the consideration of the particle cohesion was proposed. The bed voidage at Minimum Fluidization (emf) and the maximum dense phase voidage (ed,max) were shown to correlate well with a dimensionless cohesion index (σ*). All these new correlations showed good agreements with the experimental data for various types of Group C+ particles.

  • Minimum Fluidization Velocity growth due to bed inventory increase in an air dense medium fluidized bed
    Chemical Engineering Journal, 2019
    Co-Authors: Jesse Zhu, Yuemin Zhao, Shahzad Barghi, Zhenfu Luo, Chenlong Duan
    Abstract:

    Abstract Minimum Fluidization Velocity is one of the most important Fluidization characteristics when applying an Air Dense Medium Fluidized Bed to dry coal beneficiation. Measurements were carried out for magnetite particles (150–300 μm) and the binary mixtures of magnetite mixed with sand/gangue/coal particles (300–425 μm) to determine the influence of bed inventory on the characteristics at incipient Fluidization state. The experimental results demonstrate that the Minimum Fluidization velocities of both single and binary mixtures of solid particles increase with increasing bed mass, which has not properly accomplished by the existing equations. The correlation proposed by Wen and Yu has been modified to predict the Minimum Fluidization Velocity as a function of bed inventory. It only requires the knowledge of Archimedes number and the pressure drop of fluidized bed. This correlation is in reasonable agreement with almost all available data in the literature and the present work.

  • effects of acoustic vibration on nano and sub micron powders Fluidization
    Powder Technology, 2011
    Co-Authors: S Kaliyaperumal, Shahzad Barghi, Jesse Zhu, Lauren Briens, Sohrab Rohani
    Abstract:

    Fluidization of nano and sub-micron powders with and without acoustic vibration was investigated. The effects of sound pressure level and frequency were studied. Loudspeakers located under the distributor plate were used as the sound source to disintegrate larger agglomerates concentrated at the bottom of the bed. Nanoparticles showed fluid-like behavior similar to Geldart's A group and application of sound vibration improved their Fluidization quality. Submicron particles were hard to fluidize and their Fluidization quality was partially improved by sound excitation. Bed compaction, caused by rearranging of the agglomerates, was observed for submicron particles at low gas velocities while the bed was fixed. Nanoparticles did not experience any bed compaction. Sound vibration led to a decrease in Minimum Fluidization Velocity and an increase in bed pressure drop and bed expansion for both types of particles. The Fluidization quality of both particles increased at low frequencies, while the reverse was observed at higher frequencies. Fluidization of these particles was improved by increasing sound pressure level. There was a critical sound pressure level of 110 dB, below which the effect of sound vibration was insignificant. A novel technique was employed to find the apparent Minimum Fluidization Velocity from pressure drop signals.

Chenlong Duan - One of the best experts on this subject based on the ideXlab platform.

  • Minimum Fluidization Velocity growth due to bed inventory increase in an air dense medium fluidized bed
    Chemical Engineering Journal, 2019
    Co-Authors: Jesse Zhu, Yuemin Zhao, Shahzad Barghi, Zhenfu Luo, Chenlong Duan
    Abstract:

    Abstract Minimum Fluidization Velocity is one of the most important Fluidization characteristics when applying an Air Dense Medium Fluidized Bed to dry coal beneficiation. Measurements were carried out for magnetite particles (150–300 μm) and the binary mixtures of magnetite mixed with sand/gangue/coal particles (300–425 μm) to determine the influence of bed inventory on the characteristics at incipient Fluidization state. The experimental results demonstrate that the Minimum Fluidization velocities of both single and binary mixtures of solid particles increase with increasing bed mass, which has not properly accomplished by the existing equations. The correlation proposed by Wen and Yu has been modified to predict the Minimum Fluidization Velocity as a function of bed inventory. It only requires the knowledge of Archimedes number and the pressure drop of fluidized bed. This correlation is in reasonable agreement with almost all available data in the literature and the present work.

K.c. Biswal - One of the best experts on this subject based on the ideXlab platform.

  • studies on pressure drop and Minimum Fluidization Velocity of gas solid Fluidization of homogeneous well mixed ternary mixtures in un promoted and promoted square bed
    Chemical Engineering Journal, 2008
    Co-Authors: Hara Mohan Jena, G K Roy, K.c. Biswal
    Abstract:

    Abstract This paper reports the experimental finding relating to Fluidization characteristics of homogenous well-mixed ternary mixtures of three different particle size at varying compositions. The study has been carried out in an un-promoted as well as a rod-promoted square bed. The bed voidage, fixed bed pressure drop and the Minimum Fluidization Velocity have been obtained for both the above-mentioned beds. The dependence of these quantities on average particle diameter and mass fraction of the fines in the mixture for both types of beds has been discussed. The bed voidage and Minimum Fluidization Velocity have been found to decrease with increase in the mass fraction of fines in the mixture. The experimental values of fixed bed pressure drop have been compared with those predicted from equations available in literature. The Kozney–Carman equation has been found to be significant in the present case. The experimental values of Minimum Fluidization Velocity have been compared with the respective values calculated from the correlations proposed by earlier investigations for mono-size and binary mixture of particles using the Sauter mean diameter for the particle size. The values for Minimum Fluidization Velocity calculated from the equation of Wen and Yu have been found to be close to the experimental values.

  • Minimum Fluidization velocities and maximum bed pressure drops for gas solid tapered fluidized beds
    Chemical Engineering Journal, 2007
    Co-Authors: Sanjeeb Mohanty, K.c. Biswal
    Abstract:

    Hydrodynamic characteristics of tapered fluidized beds differ from that of conventional columnar beds by the fact that a Velocity gradient exists along the axial direction of the bed. To study the characteristics of tapered beds, several experiments have been carried out with different tapered angles of the bed, with regular as well as irregular particles of different sizes and densities. The tapered angles of the beds have been found to affect the characteristics of the bed. Models based on dimensionless analysis have been proposed to predict the Minimum Fluidization Velocity and maximum pressure drop for gas–solid tapered fluidized beds. Experimental values of Minimum Fluidization Velocity and maximum bed pressure drop with air as the fluidizing medium compare well with that predicted by the proposed models. The results have also been compared with other models available in the literature.

Alexander Penn - One of the best experts on this subject based on the ideXlab platform.

  • real time magnetic resonance imaging of bubble behavior and particle Velocity in fluidized beds
    Industrial & Engineering Chemistry Research, 2018
    Co-Authors: Alexander Penn, Christopher M Boyce, Thomas Kovar, Takuya Tsuji, Klaas P Pruessmann, Christoph R Muller
    Abstract:

    Snapshots of particle concentration and Velocity fields in bubbling gas–solid fluidized beds were acquired using magnetic resonance imaging. Using a recently developed multichannel radiofrequency receiver coil in combination with fast readout techniques, adapted from medical MRI protocols, the temporal resolution was 7 and 18 ms for two-dimensional images of particle concentration and Velocity fields, respectively. A cylindrical bed with 190 mm diameter and 300 mm height was filled to heights of 100, 150, and 200 mm with spherical 1 and 3 mm diameter particles and fluidized at ratios of superficial gas Velocity to Minimum Fluidization Velocity (U/Umf) of 1.2, 1.5, 2.0, 3.0, and 4.0. The effects of these varying parameters on the number of bubbles, bubble diameter, bed height, and particle speed are investigated. It is hoped that these data sets will become important benchmarks against which computational, analytical, and empirical models can be validated.

  • Real-Time Magnetic Resonance Imaging of Bubble Behavior and Particle Velocity in Fluidized Beds
    2018
    Co-Authors: Alexander Penn, Christopher M Boyce, Thomas Kovar, Takuya Tsuji, Klaas P Pruessmann, Christoph R. Müller
    Abstract:

    Snapshots of particle concentration and Velocity fields in bubbling gas–solid fluidized beds were acquired using magnetic resonance imaging. Using a recently developed multichannel radiofrequency receiver coil in combination with fast readout techniques, adapted from medical MRI protocols, the temporal resolution was 7 and 18 ms for two-dimensional images of particle concentration and Velocity fields, respectively. A cylindrical bed with 190 mm diameter and 300 mm height was filled to heights of 100, 150, and 200 mm with spherical 1 and 3 mm diameter particles and fluidized at ratios of superficial gas Velocity to Minimum Fluidization Velocity (U/Umf) of 1.2, 1.5, 2.0, 3.0, and 4.0. The effects of these varying parameters on the number of bubbles, bubble diameter, bed height, and particle speed are investigated. It is hoped that these data sets will become important benchmarks against which computational, analytical, and empirical models can be validated