A local invention that promises to revolutionise one of KwaZulu-Natal’s key agricultural crops is up for a prestigious African engineering prize.
Adrian Padt, owner of Durban-based Rocket Works is among 16 talented African engineers who have been shortlisted for the 2019 Africa Prize for Engineering Innovation with products that include bicycles made of bamboo, anti-fraud facial recognition tech and antibacterial soap made from agricultural waste.
Padt, who graduated with a Bachelor of Technology in Mechanical Engineering from the Durban University of Technology in 1994, was nominated for DryMac, a containerised drying system that uses burning biomass instead of electricity to dry and preserve crops.
According to the competition organisers, the UK’s Royal Academy of Engineering, the drier is revolutionary because it replaces traditional methods of crop preservation like refrigeration and dehydration, both of which use large amounts of energy.
The winner will walk away with $32,000 (R460 000), while three runners-up will be awarded around $12,800 (R184 000).
While Padt believes his invention can be used for a range of crops, he’s focussing on macadamia nuts for now.
He said burgeoning macadamia plantings around the globe have meant that macadamia processors and farmers alike have had to invest into expanded drying and storage capabilities on site. Traditional solutions are expensive to build and run; and are typically unaffordable for growers on the small – medium end of the spectrum.
“We are really excited by the results achieved in our on-farm trial of the DryMac. It is a modern solution that for the first time combines refrigeration technology with heat pump drying, to create a unit that can both dry and store macadamias,” Padt said.
“Together, this technology delivers superior output, including over 65% cost savings on electricity, depending on your current energy usage baseline.”
The pilot test results demonstrate the potential to dry nuts at an average temperature of 28°C; between 4 – 10 ° lower than traditional methods, that typically use electrical elements and large fans, which are heavily reliant on electricity. Because the nut is exposed to lower temperatures during drying, the positive spin-off is a better quality of nut, which could be adversely affected when dried at temperatures that are too high.
“Precision farming, including adoption of new technologies that better manage and refine agricultural output, is on the rise. Farmers and stakeholders throughout the value chain are well positioned to pioneer and assimilate the benefits of the DryMac. It creates scope for financial savings, increased quality and throughput, together with having an environmentally sustainable approach in the drying process of macadamias.”
DryMac relies on the refrigeration aspect of its design to physically condense water removed from the nut, while simultaneously adding heat to promote the drying process. It is controlled automatically to an exact equilibrium to ensure all nuts are dried to the optimum level; as well as protecting them from over-drying.
Using existing reefer containers, a globally adopted intermodal product (typically used to transport goods requiring temperature-controlled conditions), the DryMac is specifically manufactured to accommodate macadamias in bins. “It is a simple ‘plug and play’ solution, with a straight-forward installation process.”
DryMac is portable and can be stacked if there is limited space. It is notably more cost and time effective than building a traditional bricks and mortar drying facility. By simply adding more units, it is designed to scale to a larger facility if required. An existing global network of spare parts is already available for most of the components of the container refrigeration units.
Uniquely, it can switch to a refrigerated storage unit for fruit and vegetables; as well as be configured to dry product, like in the case of dried mango production. It could, if configured modularly, function in one way in macadamia season, and another in avocado season, for example.
Being mobile, a farmer can transport the DryMac from farm to farm as required. When equipped the DryMac offers a remote monitoring, alarming functions and control ability. The holding company, RocketWorks, has a database that will monitor, and be able to offer drying and maintenance advice on each of its units.
“Initial discussions with growers and leading processors in South Africa have been promising; the return on investment is achieved quickly. The benefits are clear and tangibly relevant to any macadamia operation. DryMac can be delivered within six weeks of placing an order, and we look forward to further engagement with the industry,” Padt said.
