Profiling device for determining liquid properties in tanks

Speaker:
Sorvisto, Vikke; Rocsole Ltd; Finland

Authors:
Sorvisto, V.; Rocsole Ltd; Finland
Mononen, M.; Rocsole Ltd; Finland
Voutilainen, A.; Rocsole Ltd; Finland
Lehikoinen, A.; Rocsole Ltd; Finland
Laakkonen, P.; Rocsole Ltd; Finland

ID: ECNDT-0254-2018
Download: PDF

When liquids are stored in tanks, it is important to know liquid properties such as their quality, phase separation, usage properties and water content etc. Methods currently used are mostly based on taking samples. This approach is difficult and slow since the samples have to be analyzed in a laboratory and sometimes the number of samples needed for desired resolution can be quite large. Rocsole has developed a solution to measure liquid properties, components and interfaces directly in a tank. The tank scanning device is used to estimate vertical permittivity and conductivity profile in a tank. Measurements are based on low amplitude voltages and electric currents so no radioactive sources are used. The method is also suitable for slurries and emulsions. Tank can also contain both insulating and conductive liquids. It is noticeable that the device works also when contaminated so it is perfect for environments where contamination of meters is a serious problem and conventional meters give false readings. A tripod and winch are used to lower the device in to the tank through a hatch located on top of the tank. The device is attached to the winch by wire rope and is connected to the control unit and PC through a separate data/power cable. Only the device and part of the wire goes inside the tank. All other equipment is located on top of the tank. Measurement time is dependent on the height of the tank and desired resolution in vertical direction. For example in the case of 18 m high tank and with desired resolution of 50 cm, total of 37 measurements at different heights are needed. In this case the measurement time would be approximately 0.5 hour. The forthcoming extended abstract will introduce a typical tank scanning procedure followed by results and conclusions.