Dry your sawdust without using lots of energy
Everyone working with small-scale wood processing dreams of making their own fuel pellets from all the sawdust they produce. The dream is blocked by the energy cost of drying the sawdust. The Swedish company Läppeställaren appears to have solved that problem.
At the Elmia Wood 2009 international forestry fair a completely new type of dryer was presented. It was designed and built six weeks before the fair and already has a patent pending. Its name is Läppe Torken.
The dryer’s creator is Fredrik Malmberg, a well-known serial innovator. At the last Elmia Wood he presented a unique machine that shreds timber into sawdust without taking the long way round via sawing or planing.
“We changed our heating fuel from wood to pellets and so I had the idea of making my own pellets and selling the extra, but the problem was how to dry the sawdust,” he explains.
The solution is a dryer without fans. The sawdust first passes through a grinder and is then transported up to the top of the dryer. The dryer consists of nine levels, each with a heated floor. The sawdust falls down through the levels and comes out with a moisture content of 5 to 10 percent.
“This model dries fifty to sixty kilos of sawdust an hour. You can increase the capacity by adding more levels,” Fredrik says.
The first prototype was presented at Elmia Wood and due to its very brief existence there is not yet any data on its energy consumption, but the 3 kilowatt electric heater that was used at the fair was fully sufficient. Any heat source at all can be used because it is circulating water that heats the dryer.