Process Tomographic Measurements of Granular Flow in a Pneumatic Conveying System

Abstract:

The application of process tomography (PT) technologies, i.e. Electrostatic Tomography (EST) and Electrical Capacitance Tomography (ECT) to investigate complex industrial processes has obtained wide popularity in recent years. This study focuses on the characterization of non-uniformly distributed electrostatic effects across the cross-section of a pneumatic transportpipe. A digital electrometer was used to measure the electrostatics current and an ECT was used to observe the particle distribution in a vertical pipe. Due to non-uniform particle-wall collisions, the electrostatics generated was observed to be non-uniformly distributed across the pipe cross-section, especially at pipe bends and in a vertical pipe. Large electrostatic effects were associated with high particle concentration in the pipe. There was a good correspondence between the electrostatic effects measured and particle concentration distributions obtained using ECT. Based on ECT measurements at the vertical pipe section, it was observed that particles tended to concentrate at sections where generation of electrostatic charges was high. Thus, it is clear that electrostatic effects should be the key factor giving rise to non-uniform particle concentration distribution in pneumatic transport lines.

• Periodical: Advanced Materials Research (Volume 508)
• Pages: 75-79
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.508.75
• Online since: April 2012
• Authors: Jun Yao, Eldin Wee Chuan Lim, Chi Hwa Wang, Ning Li
• Keywords: ECT, Electrostatics, EST, Nuclear Engineering, Particle, Process Tomography

References

[1] S.M. Rao, K.W. Zhu, C.H. Wang, S. Sundaresan, Electrical capacitance tomography measurements on the pneumatic conveying of solids. Ind. Eng. Chem. Res. 40 (2001) 4216-4226.

DOI: 10.1021/ie0100028

[2] J. Yao, Y. Zhang, C. H. Wang, Y. C. Liang, On the electrostatic equilibrium of granular flow in pneumatic conveying systems. AIChE J. 52(2006) 3775.

DOI: 10.1002/aic.10991

[3] K. W. Zhu, S. M. Rao, C. H. Wang, S. Sundaresan, Electrical capacitance tomography measurements on vertical and inclined pneumatic conveying of granular solids. Chem Eng Sci. 58(2003) 4225-4245.

DOI: 10.1016/s0009-2509(03)00306-3

[4] J. Yao, Y. Zhang, C. H. Wang, S. Matsusaka, H. Masuda, Electrostatics of the granular flow in a pneumatic conveying system. Ind Eng Chem Res. 43(2004)7181-7199.

DOI: 10.1021/ie049661l

[5] J. Yao, C. H. Wang. Granular size and shape effect on electrostatics in pneumatic conveying systems. Chem Eng Sci. 61(2006) 3858-3874.

DOI: 10.1016/j.ces.2006.01.015

[6] S. Matsusaka, T. Nishida, Y. Gotoh, H. Masuda, Electrification of fine particles by impact on a polymer film target. Adv Powder Technol. 14(2003) 127-138.

DOI: 10.1163/156855203762469939

[7] E. W. C. Lim, Y. Zhang, C. H. Wang, Effects of an electrostatic field in pneumatic conveying of granular materials through inclined and vertical pipes. Chem Eng Sci. 61(2006)7889–7908.

DOI: 10.1016/j.ces.2006.07.045

[8] J. Yao, L. K. Lim, J. Xie, J. Hua, C. H. Wang, Characterization of electrospraying process for polymeric particle fabrication. J. Aerosol Sci. 39(2008) 987.

DOI: 10.1016/j.jaerosci.2008.07.003

[9] G. T. Bolton, M. Bennett, M. Wang, C. Qiu, M. Wright, K. M. Primrose, S. J. Stanley, D. Rhodes, Development of an electrical tomographic system for operation in a remote, acidic and radioactive environment. Chem. Eng. J. 130(2007) 165-169.

DOI: 10.1016/j.cej.2006.06.019

[10] S. J. Stanley, Tomographic imaging during reactive precipitation: mixing with chemical reaction, Chem. Eng. Sci, 61(2006)7850-7863.

DOI: 10.1016/j.ces.2006.09.029

[11] J. Yao, B. Z. Zhang, J. R. Fan, An experimental investigation of a new method for protecting bends from erosion in gas-solid flows. Wear 240(2000) 215.

DOI: 10.1016/s0043-1648(00)00359-8