A modified correlation to calculate solid friction factor for horizontal dilute phase pneumatic conveying

The calculation accuracy of solid friction factor (fp) is important for the prediction of pressure drop, gas–solid drag force and particle velocity in a horizontal dilute phase pneumatic conveying system. In this study, some modifications were applied to the commonly-used fp correlation developed by Yang. First, the data processing to implicitly correlate fp was improved. Unlike the method used Yang's derivation, the solid volumetric concentration, the ratio of the particle's radial velocity to axial velocity and the ratio of inertial force to gravity force of the fluid were separately used instead of combining together. In addition, the sphericity of the particles was considered such that the correlation can be valid for the non-spherical particles. Experiments were also conducted to validate the correction of the modified correlation. Compared with the experimental data, the modified correlation has remarkably better accuracy on fp prediction than the existing correlation. Moreover, the correlations of solid velocity and pressure drop based on the newly proposed fp correlation were derived. The predictions of the derived correlations agree well with the present and literature experimental data.

The figure depicts the comparison of solid friction factor between the present correlation and Yang′s. It can be clearly seen that fp′s calculated by the present correlation are within an error range of ± 15% against most of the present experimental data, while fp′s calculated by Yang′s correlation do not fit the experimental data well.Figure optionsDownload as PowerPoint slideHighlights
► Different dimensionless group was used for correlating the solid friction factor.
► The sphericity of the particles was considered.
► The calculated fp agrees the experimental fp well.
► The predictions of solid velocity have good agreement with the experimental data.
► The calculations of pressure drop using newly correlation of fp fit the literature data well.