The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform

Wuqiang Yang - One of the best experts on this subject based on the ideXlab platform.

  • investigation of flow hydrodynamics and regime transition in a gas solids fluidized bed with different riser diameters
    Chemical Engineering Science, 2014
    Co-Authors: Jiamin Ye, Haigang Wang, Wuqiang Yang
    Abstract:

    It is important to understand the flow hydrodynamics behavior of a circulating fluidized bed (CFB) reactor for efficient operation. The objective of this research is to identify and characterize the flow regimes in a fluidized bed with different riser diameters. For this purpose, electrical capacitance tomography (ECT) combined with Pressure measurement has been used to investigate the flow characteristics and flow regime transitions. Experiment was carried out in a cold gas-solids fluidized bed to investigate the flow regimes and the transition velocities. Three risers of different diameter, 10, 12 and 15cm, are designed and used for comparison. A twin-plane ECT sensor and a Differential Pressure Transducer are used to obtain the solids volume fraction and Differential Pressure in the bottom region. Different flow regimes including bubbling, slugging and turbulent flow regime were formed with two distinct transition velocities. The flow characteristics are investigated in terms of solids volume fraction, bubble diameter and bubble rising velocity. The transition velocities are compared based on the ratio of the static bed height to bed diameter (Hst/D) and the measured position (i.e. the axial position and radial position). ?? 2014 Elsevier Ltd.

D Zhao - One of the best experts on this subject based on the ideXlab platform.

  • Pressure drop void fraction and flow pattern of vertical air silicone oil flows using Differential Pressure Transducer and advanced instrumentation
    Chemical Engineering Research & Design, 2020
    Co-Authors: M Abdulkadi, D G Jatto, Lokma A Abdulkareem, D Zhao
    Abstract:

    Abstract New data for Pressure drop, void fraction and flow pattern in a vertical riser using air–silicone oil as the system fluid are reported in this work. A Differential Pressure cell (DP cell) was used to measure the Pressure drop. Also, void fraction data were recorded simultaneously by an electrical capacitance tomography (ECT) and wire mesh sensor (WMS). The observed flow patterns are the spherical cap bubble, slug and churn flows. However, only the slug flow without the presence of churn flow is seen within the transition line as predicted by the map. The characteristic probability density function (PDF) derived from void fraction data was used to determine the flow patterns. A comparison between present experimental results and the air–water data reported in the literature was carried out and various levels of agreement were achieved. The PDFs obtained from the DP cell signals for spherical cap bubble and slug flows significantly differ from those derived from the ECT and WMS outputs. Current void fraction and Pressure gradient results were compared with the values predicted by ten empirical correlations selected from the literature. Statistical tools such as Mean Square Error (MSE), Root Mean Square Error (RMSE) and Mean Absolute Percentage Error (MAPE) were applied in the comparison. The Greskovich and Cooper correlation gave the least MSE, RMSE and MAPE values of 0.0007908, 0.013 and 3.05%, respectively for slug flow.

Charles Wang Wai Ng - One of the best experts on this subject based on the ideXlab platform.

  • a modified triaxial apparatus for measuring the stress path dependent water retention curve
    Geotechnical Testing Journal, 2012
    Co-Authors: Charles Wang Wai Ng, C F Chiu
    Abstract:

    Although the effects of stress on the water retention curve (WRC) of a soil have been addressed in recent research, few studies have directly addressed the effects of isotropic and deviatoric stress paths on the WRC. In this paper, a modified triaxial apparatus is developed for measuring the stress path-dependent water retention curve (SDWRC) of unsaturated soils under isotropic and deviatoric stress conditions. An open-ended, bottle-shaped inner cell is installed together with a Differential Pressure Transducer to measure the total volume change of a specimen for the correct determination of the degree of saturation of an SDWRC. The device is calibrated. Preliminary test results from compacted soil samples are also presented in order to demonstrate the key features of the equipment. These results indicate that for isotropically and normally compressed specimens, the SDWRC and shrinkage curve are influenced by the stress level.

Jiamin Ye - One of the best experts on this subject based on the ideXlab platform.

  • investigation of flow hydrodynamics and regime transition in a gas solids fluidized bed with different riser diameters
    Chemical Engineering Science, 2014
    Co-Authors: Jiamin Ye, Haigang Wang, Wuqiang Yang
    Abstract:

    It is important to understand the flow hydrodynamics behavior of a circulating fluidized bed (CFB) reactor for efficient operation. The objective of this research is to identify and characterize the flow regimes in a fluidized bed with different riser diameters. For this purpose, electrical capacitance tomography (ECT) combined with Pressure measurement has been used to investigate the flow characteristics and flow regime transitions. Experiment was carried out in a cold gas-solids fluidized bed to investigate the flow regimes and the transition velocities. Three risers of different diameter, 10, 12 and 15cm, are designed and used for comparison. A twin-plane ECT sensor and a Differential Pressure Transducer are used to obtain the solids volume fraction and Differential Pressure in the bottom region. Different flow regimes including bubbling, slugging and turbulent flow regime were formed with two distinct transition velocities. The flow characteristics are investigated in terms of solids volume fraction, bubble diameter and bubble rising velocity. The transition velocities are compared based on the ratio of the static bed height to bed diameter (Hst/D) and the measured position (i.e. the axial position and radial position). ?? 2014 Elsevier Ltd.

M Abdulkadi - One of the best experts on this subject based on the ideXlab platform.

  • Pressure drop void fraction and flow pattern of vertical air silicone oil flows using Differential Pressure Transducer and advanced instrumentation
    Chemical Engineering Research & Design, 2020
    Co-Authors: M Abdulkadi, D G Jatto, Lokma A Abdulkareem, D Zhao
    Abstract:

    Abstract New data for Pressure drop, void fraction and flow pattern in a vertical riser using air–silicone oil as the system fluid are reported in this work. A Differential Pressure cell (DP cell) was used to measure the Pressure drop. Also, void fraction data were recorded simultaneously by an electrical capacitance tomography (ECT) and wire mesh sensor (WMS). The observed flow patterns are the spherical cap bubble, slug and churn flows. However, only the slug flow without the presence of churn flow is seen within the transition line as predicted by the map. The characteristic probability density function (PDF) derived from void fraction data was used to determine the flow patterns. A comparison between present experimental results and the air–water data reported in the literature was carried out and various levels of agreement were achieved. The PDFs obtained from the DP cell signals for spherical cap bubble and slug flows significantly differ from those derived from the ECT and WMS outputs. Current void fraction and Pressure gradient results were compared with the values predicted by ten empirical correlations selected from the literature. Statistical tools such as Mean Square Error (MSE), Root Mean Square Error (RMSE) and Mean Absolute Percentage Error (MAPE) were applied in the comparison. The Greskovich and Cooper correlation gave the least MSE, RMSE and MAPE values of 0.0007908, 0.013 and 3.05%, respectively for slug flow.