Sifelani Tsiko Agric, Environment & Innovations Editor
A LOCAL engineering firm, Mamsen Engineering, has developed an energy-efficient Twin-Turbo tobacco curing barn that is set cut energy bills for tobacco farmers and reduce the impact on the environment.
The Twin-Turbo Barn was successfully tested at Kutsaga Research Station in the capital run by the Tobacco Research Board. The innovative technology has since been certified as a next generation energy-saving sustainable tobacco curing system.
Zimbabwe desperately needs sustainable tobacco curing processes that are environmentally friendly, energy efficient and capable of reducing the fuel requirements for curing tobacco.
TRB general manager Dr Dahlia Garwe told The Herald that the new energy-efficient curing barn could easily ensure the survival of Zimbabwe’s tobacco industry, which is under immense pressure to ensure smallholder farmers reduce the cutting down of trees used for curing processes.
“We, as the TRB and as part of the tobacco industry, are extremely excited about this innovation,” she said. “Zimbabwe has abundant coal reserves and this should result in a substantial reduction in wood use. Deforestation is a serious issue now and the new barn offers a solution for both large- and small-scale tobacco growers.”
Mamsen Engineering has successfully introduced the new tobacco barn in Mozambique and the company is keen to introduce it to the entire SADC region to help reduce deforestation and save on energy bills.
“For us this season, the barn will be rolled out, but owing to the current economic difficulties it may be necessary to begin with retrofitting some of the existing barns with this kind of technology so that we can use coal instead of firewood,” Dr Garwe said.
The Twin–Turbo Barn offers a better way for tobacco farmers to cut their energy bills and operate more sustainably.
The technology is made up of a lightweight air-tight steel tube structure cladded with IBR sheeting and insulated on the inner structure with ally cushion for reduction in thermal inertia.
In a report, Hanif Mahomed of Mamsen Engineering said the Twin–Turbo Barn allows the tobacco farmer to cure their tobacco using coal without the use of an electrical or solar-powered fan for combustion with fuel efficiencies in the range of 0,85 kg coal per kilogramme of cured tobacco.
“This cheaper barn model is suitable for small-scale and communal farmers who can easily assemble it and operate using coal, saw dust, LP gas and biofuels.
“In addition to the above, farmers can use alternative sources of fuel such as wheat stalks, maize stover and hay to cure their tobacco. The multi-purpose Twin-Turbo Barn can also be used in the timber, fruit, biltong and paprika industries for drying purposes. The barn can also be retrofitted into existing brick barns.
“Apart from this, it allows ease of transport, assembly and disassembly as it can be delivered in a knock-down kit form.
“The heat exchanger is connected to steel flue pipes, and damper control boxes with the aid of fasteners, bolts and nuts that enable the farmer to easily remove soot build-up in the flue pipes before every cure commences. High energy efficiency is achieved through the diversion of waste exhaust gases from one barn to the second barn, providing adequate heat for the colouring stage to be completed in the second barn without burning any fuel in that barn.
“A lead time of at least 48 hours is required for the first barn to achieve this,” the designers said.
Tobacco curing — the act of drying tobacco in readiness for the market — has led to the destruction of large tracts of forests in the country.
Zimbabwe, the world’s fourth largest producer of flu-cured tobacco, has more than 90 000 registered growers made up largely of smallholder farmers who rely heavily on wood for curing.
In a survey carried out at the country’s four auction floors, the majority of farmers conceded that they were solely relying on wood for curing their tobacco.
The tobacco industry’s value chain remains one of the country’s largest, employing over two million people.
In the 2017/18 cropping season, tobacco generated up to US$1 billion from 253 million kilogrammes sold through the contract and auction floors.