Willo’s check valves make a difference to the climate
The cleantech company Swedish Stirling has developed an innovative solution for recovering energy from industrial residual gases and waste heat – and converting it into carbon-neutral electricity. A small, but very important, part of the solution is the custom-made check valve from Småland-based Willo.
PWR BLOK is a container-based solution in which Swedish Stirling uses Stirling engines to recover energy from industrial residual gases and waste heat. The company’s head office is located in Gothenburg, and the production facilities are situated in Sibbhult in the Swedish province of Skåne. The company also has a subsidiary in South Africa.
Swedish Stirling has initially focused on the recovery of residual gases from the production of ferrochrome, which is used in the manufacture of stainless steel. About a third of global ferrochrome production takes place in South Africa.
The process is very energy-intensive and costly, with half of the energy lost in the form of residual gases. These gases also have a major negative climate impact that is around 30 times greater than carbon dioxide, and they are therefore simply burned up in tall chimneys – without being able to utilise the heat energy.
The first prototype of PWR BLOK was shipped to South Africa in 2019, and the company now has contracts with two of the country’s largest producers of ferrochrome. In 2022, Swedish Stirling has also commenced mass production of PWR BLOK in Sibbhult.
Solves the industry’s challenges
PWR BLOK makes it possible to recover part of the energy in the residual gases by channelling and combusting the gas with the help of the 14 Stirling engines contained in each unit. The Stirling engine, which is a heat engine, converts heat from the combustion of the gas into kinetic energy, which is then converted into electricity via a generator located adjacent to each engine.
The electricity is then channelled back to the smelter for use in the smelting process. Thanks to this recovery of energy, the smelters’ need to buy electricity is reduced by up to 15 percent, and there is also a reduction in their environmental impact.
“Being able to provide new technology that reduces both the industry’s costs and its climate footprint is extremely positive and extremely relevant in the current age of environmental focus. This is a view that is also shared by our suppliers, such as Willo”, says Peter Bertilsson, Sourcing and Supply Manager at Swedish Stirling.
Willo a genuine workshop company
The Stirling engines are the heart of the PWR BLOK solution, and a small, yet very important, component of these engines is the check valve, which ensures that the right amount of gas flows in the right direction at the right time. The valve, which opens and closes around 2,000 times a minute, is made, pressure-tested and delivered by Willo, a company based in the Swedish province of Småland.
“From our perspective, Willo is the company that is best suited to produce the valve. Willo is a genuine workshop company with a high level of expertise, a well-considered holistic perspective, the market’s most modern machinery, and a high level of quality throughout the production line”, Peter Bertilsson explains.
“We take great care in choosing the right suppliers – companies that challenge us, ask relevant questions and are price-conscious, and with whom we can work together to solve challenges and problems. From our very first contact with Willo 3–4 years ago, we gained an extremely positive impression of both the company and its staff, an impression that remains to this day with the commencement of mass production of PWR BLOK”, Peter Bertilsson concludes.
