Buntning av grot med lastbilsmonterad utrustning
During the transportation of logging residues (LR) the material´s low density is a problem that results in low use of pay-load capacity. Comminution or compression of LR are possible methods to increase pay-loads. In the present thesis studied a bundling machine which was mounted on a truck chassis, and the subsequent transport and crushing. The truck bundler created bundles that were larger and longer than other bundling equipment on the market. The objectives were to determine the total time consumption and its allocation over work element and machinery, to measure dry matter (DM) content of green and brown LR-bundles. In addition the objectives was also, the system's economy was addressed.
The base of the thesis was the time studies which were conducted on bundling, transport and crushing. One study site generated brown LR and another green LR. Produced bundles were transported by truck to industry where they were crushed. DM content and net calorific value were determined.
Produced bundles were on average 5.1 m long and 0.88 m in diameter. DM content of brown and green bundles were 62.4 and 54.9 percent. The mean mass was 716 kg
(419.5 kg DM) and contained a net calorific value of 2.1 MWh. The productivity was 11.9 bundles per E0-hour with no significant difference between the two LR types. To produce one bundle required 5.47 c-min which correspond to 4.95 tonnes DM per E0-hour.
Maximum load on the truck and trailer were 30 bundles (21.5 tons) and pay-load capacity was used to 69 percent.
Crushing capacity was 177 bundles per E0-hour, which corresponded to 73.5 tonnes DM per hour.
Fix cost for the compression, loading, unloading, crushing and transport was
89.7 SEK/MWh for brown bundles and 94.0 SEK/MWh of green bundles plus a transport cost of 0.41 SEK/MWh per km and 0.47 SEK/MWh per km, respectively.
Compared to loose LR, brown LR-bundles were profitable in the system analysis to transport when the distance exceeded 100 km. The corresponding transport distance for the green bundles was 75 km.