Working on behalf of Balfour Beatty, Steve Vick International (SVI) worked collaboratively in developing a cost effective, more environmentally friendly solution to manage heat transference within a ducted 400kv cable system.
The project involved a 9km section where the cables were required to be run underground and be installed into ducts.
The project involved a 9km section
Where these ducts crossed under water courses, roads, rivers, streams, and drainage channels they were required to be filled with Cebo Gel because, under crossings such as these, the cables are laid much closer together. This can cause the cables to transfer heat to each other and overheat which could result in them failing. Cebo Gel helps to conduct this heat and disperse it. There were 7 crossings in total for the 12 cables to pass under. They were split in two so that 6 cables ran either side of each crossing, resulting in a total of 144 sleeves of varying volumes and lengths that required filling.
Balfour Beatty specified that they wanted to use Cebo Gel
Balfour Beatty specified that they wanted to use Cebo Gel as it’s the best form of filling ducts because it’s composed of a specially selected Bentonite/graphite mixture and is a unique, all-in-one solution for promoting efficient heat transfer from power cables to the surrounding soil. Cebo Gel is a nonhardening suspension and therefore easy to remove after a certain period of time, if required. The product is cement-free and provides high flowability over long distances.
SVI, who have many years’ experience in grouting, adapted their current grout pump to work with Cebo Gel. This has the distinct advantage that no large vats of premixed Cebo Gel are required on site and the use of lagoons is not necessary thus having a significant benefit to the environment. The SVI grout pump works continuously mixing the powder to water ratio, blending it seamlessly, allowing 4 cube per hour to be mixed and injected into the ducts. 24 cube can be achieved in 6 hours and the SVI pump guarantees a consistent mix and pump. Cebo Gel works by first filling the lowest point of the annular space and then pushing forward and working back up.
Stephen Smith, Site Manager, Balfour Beatty commented, “We were delighted with the work Steve Vick International carried out for us. Their grout pump system was so agile it could be moved around the site with ease and, because of the blending process their pump uses, the quality of their mix was also unfalteringly consistent. This method also produced minimal waste to dispose of, which was important because we were working in an Area of Outstanding Natural Beauty and was more cost efficient and environmentally friendly than some of the alternatives we looked into.”