Hydraulically Powered Wood Chip Blower in Test and Its Use Opportunity in Biofuel Supply Chain

Abstract

Most forest chips are delivered to large-sized, combined heat and power plants in Finland. In this study, we introduce and demonstrate the small-scale delivery of forest wood chips to potential clients, with the wood chips being delivered in a container truck and pneumatically blown into a storage facility. This arrangement of wood chips being blown through a pipe into a storage eliminates the ground handling while requiring a relatively small space. In the demonstration tests, we tested the volumetric flow of biomass in the hose and its noise level while the blower was blowing the material and the flow speed of the material in the hose. This study discusses the test conditions in which the compatibility and suitability of the truck and its hydraulic system were used in conventional chip delivery in Finland and the selected blower type was investigated. According to the results, the biomass volume flow was higher (~0.46 m3/min) when the blower revolution was lower (2392 - 2566 RPM). However, when the RPM was increased to ~3000, the volumetric flow decreased to ~0.24 m3/min. Similarly, the speed of the chips was higher with a lower RPM; 29.9 m/s at an RPM of 2400 and 25 m/s at an RPM of 2700. This is potentially due to both the blower and screw conveyer using the same power source. Additional optimization research would be needed to conclusively state the root cause of this phenomenon. On the other hand, chips from pruned stems had better flow than the chips from whole trees, since chips from whole tree have a wider range of chips sizes, including 1.3% of chips being in the range of 31.5 - 40 mm. The larger chips clogged the hose, which hindered the flow. Finally, the noise tests showed that it was louder at 0 degrees, which contrasted with the situation for the blower, with an aside at 90 degrees.