Dynamic Interactions between the Cutting Blade and Miscanthus Stem
Open Access
- Author:
- Toleu, Zhankozy
- Graduate Program:
- Agricultural and Biological Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- August 04, 2020
- Committee Members:
- Jude Liu, Thesis Advisor/Co-Advisor
Paul Heinz Heinemann, Committee Member
Charles David Ray, Sr., Committee Member
Paul Heinz Heinemann, Program Head/Chair - Keywords:
- Biomass
Miscanthus
Dynamic cutting
Cutting force
Cutting energy - Abstract:
- The production of renewable energy has increased significantly in recent years due to global warming and national energy security needs. Among renewables, the biomass feedstock is a promising energy source. Dedicated energy crops, short-rotation woody crops, and agricultural crop residues are considered the primary biomass feedstocks, and existing harvesting, processing technologies and equipment for agricultural crops can be used. Miscanthus is a perennial energy crop, and research has indicated its high potential to become a primary feedstock for the bioenergy industry. However, since miscanthus is relatively new to the US renewable energy industries, the traditional harvesting and processing machines have not yet fully adapted to the production of this crop. The feasibility of large-scale production of biomass crops for the bioenergy industry directly depends on the effectiveness of the harvesting and processing machines employed. High yield and stem rigidity of miscanthus complicate harvesting and processing and have caused high production costs. Thus, currently used traditional hay and forage machines may need to be modified to be suitable for this challenging crop. Improvement of harvesting, handling, and processing machinery efficiencies can be achieved by considering the mechanical and physical properties of this special crop during the machine design process. To understand miscanthus harvesting and size reduction processes, it is crucial to quantify the interactions between a cutting blade and the crop stem because cutting is a key process during harvesting, such as mowing, precutting when baling and grinding. Therefore, dynamic interactions between the cutting blade and miscanthus stem were studied in this research. The effects of a blade type, sample supporting method, cutting speed, and stem location on cutting force and energy were studied. Serrated and flat blades, one side, and both sides supporting method, upper and lower internode-node sections were tested during the experiment. The peak cutting force, the cutting energy and the cutting speed data were recorded. Overall, for the flat blade, the average peak cutting force was 264 N, and the average cutting energy was 5.9 J. The average diameter of miscanthus samples used for the treatments with a flat blade was 9.5 mm. For the serrated blade, the average peak cutting force was 250 N, and the average cutting energy was 5.75 J. The average sample diameter was 9.33 mm with the serrated blade treatments. Blade cutting speeds for all treatments ranged from 8m/s to 11.3 m/s. Statistical analysis showed that the blade type created significant differences in predicting specific cutting force (p=0.01), while for the cutting energy (p=0.084) blade type was not significant at a 95% confidence level. The stem location, whether lower or upper section of the whole plant stalk, was significant for specific cutting force, but specific cutting energy was not significant. Blade cutting speed was found to be not significant due to small cutting speed range. Finally, the stem section, whether it is node or internode, was significant in predicting the specific cutting force and the specific cutting energy.