A four metre diameter dish is being used to concentrate sunlight on what is essentially “a big kettle,” says Dr Russell Phillips, Associate Professor in Mechanical Engineering at Nelson Mandela Metropolitan University which is working in partnership with Aberdare Cables, part of the Altron Group.
If the pilot works, the technology will be adopted by Aberdare and offered to other companies in the Altron group, says Andrew Rist, group sustainability manager.
“It is part of the Aberdare drive towards sustainability. The technology we use at present is energy-hungry. Solar is a more sustainable option over the long term,” he says.
In the system being developed by NMMU, the oil in the effluent will first be removed by settling or a centrifuge, according to Phillips.
“The remaining liquid consists mostly of contaminated water and constitutes approximately 90% of the total volume of the effluent.
“This will be disposed of by evaporating it with the solar concentrator.
“The desired result will be an inexpensive means of disposing of large volumes of the effluent on site in an environmentally friendly manner,” he says.
In order to produce heat all day long, the dish will need to track the sun. The department has developed a prototype frame for the dish, and will also be programming the software to ensure the dish is optimally positioned all day.
He believes the system could also be used to help reduce the cost of the production of the heat needed for certain manufacturing processes.