Metsähakkeen jalostusarvon nostaminen eri kuivausmenetelmillä

The thesis was made for Hyötypaperi Oy. To the business activity of the company belongs the recycling of materials and carry out for re-use and the manufacture of solid biofuels and solid recovered fuels. Hyötypaperi Oy delivers forest chips to its partner incineration plants by day and night though the year. The value of the forest chips is based on its percentage of dry material. It is important to dry forest chips well before its storage in piles and delivering to incineration plants. In the thesis was examed the increasing of the degree of refinement of forest chips by different drying methods. In the thesis was examined four different drying methods of the forest chips. The methods were field-, plate-, platform- and channel drying. In the channel drying was used a mechanical blower and the other drying methods were based on the weather conditions. By all drying methods were made test dryings during the summer 2007. In the thesis was examined also the economical profitableness of the field- and channel drying. The last examination in the thesis was measuring of the forest chips’s humidity by humidity measuring equipment of sawn timber during November 2007. The field drying on the surface of asphalt is the only method of drying, which is used by Hyötypaperi Oy in its own production. There do not exist earlier properly examined facts of any drying methods of forest chips, because the drying of forest chips is a new branch. By field- and platform drying achieved lower humidity of forest chips than by plate drying. The object by using the humidity measuring equipment was to be informed of the humidity of forest chips. At present the humidity will find out after 24 hours when the sample of humidity quantity has been dried in the oven. The Lappeenranta University of Technology had the humidity measuring equipment of sawn timber. The values of humidity measured by the equipment from the sample of forest chips were 2 – 9 percent lower than the real values of humidity specified by drying in oven.