The new Vertical Shaft Brick Kiln (SA-VSBK), deployed and tested in Nepal and India and developed further in South Africa as part of a South-South technology transfer programme involving local brick makers and Swiss expertise, reduces the coal consumption required to fire the kilns by as much as 50%, says South African brick maker Langkloof Bricks executive director Nico Blake.
“The SA-VSBK, in contrast to some of the other traditional methods of brick manufacture, operates continuously throughout all weather conditions and produces high-quality clay bricks that are uniform in size, shape, strength and texture,” he says, highlighting that demand has increased substantially for these low-carbon bricks in the past year.
Langkloof Bricks has reduced wastage from 10% to less than 3%, says Langkloof Bricks production director Pieter Blake, noting that the company monitors and meets all of the emissions criteria as set out by the Department of Environmental Affairs’ Air Quality Management Directorate, which enables Langkloof Bricks to register for carbon credits under the Clean Develop- ment Mechanism of the United Nations.
“The SA-VSBK process entails clay brick batches packed and lowered into the shafts where they are preheated before entering the firing zone. Fourteen batches of 456 bricks each can be fired in a single shaft within 24 hours, which is significantly quicker and more economical than other methods,” says Rowe Construction MD and lead designer of the next generation kilns Jez Rowe.
The bricks cool as they are lowered through the shaft below the firing zone and we can produce a batch every 1.5 to 2 hours. Further, the use of air as an insulation medium and our work on increasing the efficiency of airflows as well as reducing firing energy has also reduced the price of constructing a shaft by about 30%, while improving the quality of bricks produced, he adds.
The implementation of the SA-VSBK concept, as a Swiss open-source technology, has been successfully developed into a commercial technology in South Africa with input from local engineers in the refractory, civil, ceramic, chemical and construction industries, and can now be deployed glo- bally, he notes.
“Langkloof Bricks has installed six back-to-back vertical shaft kilns and has proven the economic sustainability of the technology to supply the construction and housing industries,” says Ambassador of Switzerland to South Africa Christian Meuwly, who toured the Langkloof Bricks SA-VSBK facility in July.
“The result of Swiss technical support in the development of an economically viable and self-supporting brick making technology that reduces greenhouse emis- sions in South Africa, and also produces high-quality and environmentally valuable products, demonstrates that this change can be sustained, and we hope to see this model multiplying in South Africa on the back of these successful experiences,” says Meuwly.
The 50% fuel reduction is significant and benefits medium-sized and microenterprises, as well as larger organisations. We are conducting thermo-dynamic testing of the third- generation designs of the kilns in anticipation of expanding the six kilns at Langkloof Bricks by a further 18 kilns. This expansion demonstrates that the SA-VSBK technology is proving to be economically viable and provides the clay brick maker with a competitive advantage, notes Rowe.
“Continued local collaboration and Swiss partnerships to mitigate climate change by developing companies in an economically sustainable manner are important. The potential exists to promote, expand and increase adoption of this technology in South Africa, which will benefit the housing and construction markets,” concludes Meuwly.