COMPLETE PLANTS AND MACHINES FOR THE RECYCLING INDUSTRY Wood Grinding (Wet and Dry) Optimum crushing of wood chips! ABOVE: Bulk pellets are sealed in the cargo hold of trans-oceanic ships, and proper safety procedures have been developed for unloading at the shipment’s destination. RIGHT: Short-term transit of pellets, for example, in rail-cars from the plant to port, presents less risk of off-gas-sing and self-heating than does long-distance shipping. ties exist for wood pellets, from cylindrical silos like those used to store grains to warehouse-type facilities in which pellets are loaded by conveyor and removed by a loader. Extensive research has been conducted on the storage of grains in different types of vessels in different climates; however, very little research has been conducted on wood pellet storage. What has been done has been in closed or sealed con-tainers because of costs and other limiting fac-tors on testing. Research to date indicates that ambient temperature is the number one factor for off-gassing and self-heating. Nothing can be done to control ambient temperature, so work must be done to control the temperature within the environment where the pellets are stored. This can be done in several ways but must be considered first prior to building a facility, and not as an afterthought. Aeration, also known as active, mechani-cal, low-volume, or forced ventilation, can be defined as the forced movement of ambient air through bulk product for improvement of storability. The objectives of pellet aeration can be best described as: cooling pellets, equalizing temperatures throughout the pellets, prevent-ing biological heating in damp pellets, circulat-ing off-gasses, and removing odours created by off-gasses. Pellet aeration also helps prevent moisture migration and headspace water con-densation in humid climates. Rates of chemi-cal deterioration are very slow and sometimes insignificant at low temperatures, and increase significantly with each 10ºC increase in tem-perature. Therefore, maintaining low tempera-tures in the pellets is essential. Ambient air temperature, solar radiation, atmospheric weather changes that result in major barometric pressure fluctuations, and storage structure parameters affect the transfer of heat within the stored product. South walls in the northern hemisphere and north walls in MarCh/april 2011 AMANDUS KAHL GmbH & Co. KG SARJ Equipment Corp., Mr. Rick B. MacArthur 29 Golfview Blvd., Bradford, Ontario L3Z 2A6 Phone: 001-905-778-0073 Fax: 001-905-778-9613 [email protected] LIGNA 2011 Hall 13, Stand E 02 Hannover, Germany May 30 – June 03 www.akahl.de DRYING GRINDING CONDITIONING PELLETING COOLING PACKING 26 Canadian BIOMASS
Canadian Biomass April 2011: Page 26
