Conveying biomass wood pellets within facilities used for their production is not without its challenges. Wood pellets retain their shape from the lignin and pressure inherent in the material, but they are fragile and easily broken or damaged. To prevent pellet breakage, attrition and the production of fines during material transfer, it is essential to use equipment that is capable of the gentle conveying of biomass wood pellets.
Biomass wood pellets are produced from softwood or hardwood trees, which are logged, debarked, chipped, dried, conditioned, pelletized, and screened. Sawmill residuals, such as sawdust and shavings, are also used to produce pellets. The pellets are produced in facilities which convert the raw biomass into finished pellets.
Biomass wood pellets: types and handling characteristics
Biomass wood pellets are used as an environmentally-friendly energy source in homes and industrial facilities. Premium pellets designed for home use typically have less than 1.0% ash by weight. Industrial or standard grade pellets are usually made from wood and bark and typically have a higher ash content of 3.0% by weight or less. A trend today in many industrial facilities is to construct or convert large power boilers that will use standard grade pellets.
Biomass wood pellets have the following handling characteristics:
- They are fragile and break easily when handled.
- Pellets produce a fine dust when handled. This dust is combustible and explosive.
- Pellets flow well and are not prone to bridging if stored in dry conditions.
- Wood pellets have a moisture content that varies between 12-15%. However, they will absorb water readily, causing them to swell and break apart. For this reason, they should be kept dry when conveyed and stored.
Gentle conveying of biomass wood pellets: equipment solutions
Conveying equipment and systems used in pellet plants should minimize or eliminate impacts or rubbing, wedging or grinding actions as pellets are moved by the conveyor. The inherent fragility of biomass pellets requires the use of gentle handling conveyors. TipTrak™ continuous bucket elevators are a proven equipment solution in biomass facilities for moving pellets through the production process. Consider the advantages of TipTrak™ elevators:
TipTrak™ elevators accommodate both vertical and horizontal conveying with minimal transfer points.
- The fully interlocking buckets and rubber drive beltchainassure gentle handle and zero spillage.
- TipTrak™ PEC (fully enclosed) and Monocoque (fully sealed and gastight) models control product dusting and prevent moisture contact with finished pellets. Both models can be supplied with explosion-resistant features, including fully conductive drive assemblies to eliminate sparking, explosion-proof drive motors, and explosion relief vent panels. Conveyors can also be equipped with heat, smoke and flame sensors, as well as fire suppression equipment.
- TipTrak™ elevators can be equipped with cleanout drawers to enable the easy cleanout of any accumulated fines within the equipment. Alternatively, direct connection to a facility’s dust collection system can be enabled.
- TipTrak™ elevators have industry-leading reliability. This ensures uninterrupted throughput and minimal unplanned equipment downtime.
Inclined cleated belt conveyors from UniTrak can also be supplied to move material between various points within the pellet production process. As with our TipTrak™ bucket elevators, these conveyors can be expressly designed to accommodate the configuration and distances of your particular pellet processing line.
UniTrak’s experienced sales team will be pleased to review your biomass pellet application and recommend an appropriate equipment solution. To find out more about how UniTrak can help you with the gentle conveying of biomass wood pellets, please contact our sales team directly.