Polyvinyl chloride (PVC) pipe manufacturer DPI Plastics reports that it has managed to save about 38,78% in electricity demand within its factory by implementing power factoring technology.
The plastics product manufacturer says that it is implementing a strategic drive to reduce energy demand in the manufacturing process.
“Eskom has issued a warning of another potential power cut danger phase looming from the end of this year, prompting DPI Plastics to upgrade its manu- facturing plant to save energy. We started the gradual process through a capital investment programme about a year ago, installing transistors capable of variable load speeds to reduce electricity demand from about 3 600 kVA to about 2 200 kVA,” DPI Plastics plant engineer Gerrit Oosthuizen says.
He reports that there are several energy saving projects that the company is in the process of implementing. DPI Plastics approached the National Cleaner Production Centre (NCPC) during 2010, which undertook a survey, followed by in-depth research. The NCPC identified about six immediately implementable energy saving projects.
“Our priority is to reduce operating costs, which means that the energy used for the amount of kilograms of plastics produced must be reduced. We regard this as being a critical strategy to give us a competitive edge,” Oosthuizen adds.
The manufacturer reports that it is currently busy installing variable-speed drives in its three cooling towers. He notes that, if the speeds of the cooling towers are reduced by one-half, a significant energy saving of about R140 000 a year can be achieved. The amortisation of the upgrades is expected to be achieved in about six months.
Further, the company has installed a high-efficiency compressor, where the original capac- ity of 200 kW was reduced to 160 kW, resulting in energy cost savings of about R42 000 a year.
Oosthuizen also reports that the company has implemented load-shifting practices during peak electricity demand periods. “We do not operate our reclaim department during the peak periods and, just by slightly altering the way in which we operate, we have achieved a further energy cost saving of about R144 000 a year, without capital investment,” he says.
DPI Plastics reports that it is also looking at installing heat pumps as an alternative source of hot water, owing to these units achieving four units of heat for every one unit of energy. “This is much more efficient than traditional geyser systems,” Oosthuizen says.
“The less energy we use to manufacture our products, the more we reduce our carbon footprint,” he adds.
Oosthuizen also notes that, had the company had access to unlimited capital to immediately implement its energy saving plans, it could potentially save about R600 000 a year on energy costs.
Meanwhile, DPI Plastics technical and product manager for pressure pipe systems Renier Snyman reports that the company is also saving energy through its product solutions.
“Environment-friendly products are becoming increasingly popular among our clients. Our Gemini Biax range of PVC-orientated pipes have thinner walls, owing to the material being stronger, which, in turn, reduces the amount of plastic used to manufacture the product,” he says
Snyman explains that the pipe is stretched during production, orientating the molecules in such a way as to make the material stronger. The range also has increased reliability.
Further, DPI Plastics reports that the base materials for most plastics are generally derived from fossil fuel sources, but PVC uses about 50% less of this finite resource, owing to salt making up the other half of the material, resulting in a greener product.
The range of pipes holds further green advantages as the larger internal diameter enables a potential saving on pumping costs, owing to less-restricted flow. The pipes are also 100% recyclable.
The Gemini Biax range of pipes is becoming increasingly popular in pressure pipeline applications for potable water in civil construction, and now also in mining, owing to the development of a Victaulic jointing system. The mining system comprises a steel collar joint that will not pull apart under pressure.
“The system is designed to enable the pipes to be suspended from the roofs of mine shafts, conveying water to miners. To date, the system has been installed at two mines,” Snyman says.
The company reports that it spends about R900 000 a year on research and development (R&D) activities, and that about 90% of the R&D is done in-house, with input from chemicals giant Sasol and the Council for Scientific and Industrial Research.
Snyman says that the company voluntarily committed to removing heavy-metal-based stabil- isers from the PVC formulae, a process the company embarked on in 2006.
Further, a significant R&D focus is to find alternative stabilisers for its plastics that are more environmentally friendly.
“We have now progressed to using calcium/zinc and organic- based stabilisers. “We are continually investigating the use of more efficient additives in our PVC formulations to keep up to date with the latest developments,” he concludes.