Industrial Process Tomography - Platform II grant funded by EPSRC

FACULTY OF ENGINEERING

 
Filtration process of ERT


Typical Applications - Separation Process

1. Hydrocyclones
The application of ERT to auditing hydrocyclone separators in industrial environments was presented [1]. Disc shaped ERT sensors (eight-planes of 16-electrodes) were retrofitted onto a commercially available separator (50mm diameter) widely used in the mineral processing industry for treating fine slurries of china clay containing up to 15 wt. % solids which have a cut size in the region of 7µm. The authors demonstrated its use in laboratory, pilot plant and plant scale investigations of clay refining. The ERT sensor system was capable of observing the occurrence of faults in the underflow discharge (spraying, roping, and blockage), measurement of air-core size for different operational conditions and calculation of solids concentration profiles based on reconstructed 3D volume data, with the information obtained providing a rich source of data for model development [1].

2. Filtration
The application of ERT to pressure filtration has been widely applied in the literature to demonstrate its potential industrial applications. A single ERT sensor array (consisting of a 16-electrode ring) [2] was fitted to a commercially available 1.5m3 pressure vessel. LBP was utilised for image reconstruction of the brine slurry which was agitated and then filtered under pressure to create a filter cake.

 

The presence of a hidden trough containing water was discovered

Filtration process of ERT


 

In later investigations [3] ERT was applied to solid-liquid filtration using a 1m diameter pressure vessel (again a 16-electrode array, ITS p2000 DAS using LBP) to detect changing liquid level and filter cake visualisation, helping to identify distortion and malformation. Validation of the results was undertaken by means of off-line comparison with other process measurement techniques and operator observations. This led the authors to conclude that ERT has potential for detecting the performance of filter cakes, leading to improved product purity with potential applications in the fine chemical and pharmaceutical industries.

References:
[1] R.A. Williams, X. Jia, R.M. West, M. Wang, J.C. Cullivan, J.Bond, I. Faulks, T. Dyakowski, S.J. Wang, N. Climpson, J.A. Kostuch and D. Payton, “Industrial monitoring of hydrocyclone operation using electrical resistance tomography,” Minerals Engineering, vol. 12 (10), pp. 1245-1252, 1999.
[2] B.D. Grieve, T. Dyakowski T, R. Mann and M. Wang, “Interfacing of EIT into an industrial pressure filter: a practical example,” in: Proc. of the 1st World Congress on Ind. Proc. Tomogr., Buxton, UK, April 14-17, 1999.
[3] D. Vlaev, M. Wang, T. Dyakowski, R. Mann R and B.D. Grieve, “Detecting filter cake pathologies in solid-liquid filtration: semi-tech scale demonstration using electrical resistance tomography,” Chem. Eng. J., vol. 77, pp. 87-92, 2000.