ITS DENS-ITOMETER: An Electrical Resistance Tomography Based Densitometer

Kent Wei, Changhua Qiu, Daniel McCormack, Ken Primrose

Industrial Tomography Systems Plc (ITS), Manchester, U.K. kent.wei@itoms.com

ABSTRACT

In dredging and mining industries, density and flow rate measurements are two important parameters to indicate the process conditions during hydraulic conveying. Currently, two separate tools are required in order to obtain density (densitometer) and flow rate (flow meter) measurements, and almost all the densitometers currently installed are nuclear based, i.e. using radioactive source such as gamma ray to obtain the density values. Since utilizing radioactive source can potentially implicate operational, safety and cost issues, there has always been a great interest on developing a non- nuclear based densitometer. In this paper, an electrical resistance tomography (ERT) based densitometer will be presented. ERT utilize low frequency electrical fields to detect conductive/non- conductive materials within the transportation pipe. This non-nuclear based densitometer has advantages of robustness, safety and cost. Furthermore, its abilities of obtaining both the online cross sectional flow regime and the flow rate information can provide extra process information to operators. The performance of the ITS Dens-Itometer will be validated in several field tests in dredging/mining applications, with a comparison of density measurements using gamma ray densitometer.

Keywords hydraulic conveying, electrical resistance tomography, densitometer, dredging, mining, non-nuclear instrument