Damen has officially launched a new range of non-radioactive density meters – the CombiMeter.
On board dredgers, continuous control of the dredging efficiency is of vital importance. This is done by density measurement – continuously checking of the throughput in the dredge pipe.
For several decades this measurement had to be done using a nuclear density meter, but now Damen has put a new technique to the test on an aggregate dredger, and it has passed with flying colours. As a result, the new CombiMeter is available for all new dredgers and retrofits.
The CombiMeter consists of a flow meter and a density meter. For the flow meter, an electromagnetic flow meter by Krohne Altometer is used. This is a proven concept in the dredging industry. Added to this is a density meter based on electrical resistance tomography, as developed by ITS (Industrial Tomography Systems). Both are combined in an integrated production meter; the CombiMeter.
The CombiMeter has undergone a series of extensive field tests in the Damen Dredging test loop, in the ¡VAMOS! mining project and lastly as a full-scale test on the CEMEX aggregate dredger Sand Falcon in a Ø700 mm pipeline.
During the tests, the Sand Falcon dredged a range of materials including fine sand, coarse sand and gravel. All the tests were carried out at sea, comparing data from the new CombiMeter with that from an existing radioactive model.
All data from the CombiMeter were within a 1-3% accuracy range and showed a 0.95 correlation factor with the radioactive type. All the evidence from all the tests has led to the conclusion that the CombiMeter performs excellently in this salt water environment, in both horizontal as well as vertical pipe lines, covering a wide array of soils including silt, sand and gravel.
The CombiMeter will be installed on the marine aggregate dredger CEMEX Go Innovation, currently under construction at Damen Shipyards Galati.
Commenting the latest news, CEMEX project manager, Mr Mark Williams, said: “In keeping with the design objective of CEMEX UK Marine Ltd to build a state of the art, future-proof, aggregate dredger and to ensure the vessel’s environmental credentials, a key consideration was the elimination of potentially harmful substances. These range from toxic coatings to the radioactive source found in a conventional nuclear density meter that would prevent the new build vessel achieving an ECO notation from Lloyds Register, this being a first in the UK marine aggregate industry.”
Full results of all the tests the CombiMeter has undergone will be presented at the WEDA Dredging Summit and Expo in Chicago, on the 7 June 2019.
Damen, ITS and Krohne will be present to launch the CombiMeter to the dredging industry.