RESEARCH RESULTS ON THE DESIGN AND MANUFACTURE OF AN UNDERSTORY BIOMASS AND POST-HARVEST RESIDUES AND ORGANIC MATERIAL PROCESSOR FOR PLANTATION FORESTS

Abstract

Treatment of forest residues, including understory vegetation, branches, and bark, is a necessary operation following each harvest and reforestation cycle. The research, design and manufacturing of machinery for processing forest residues and organic materials left after plantation harvesting is essential to meet the practical demands of production and to overcome the current reliance on labor-intensive manual clearing methods, which are limited in both productivity and quality due to the lack of suitable mechanized equipment. A residue processing equipment was designed and manufactured for attachment to agricultural tractors with engine power exceeding 50 hp. The working unit adopts a toothed-drum structure, operating based on a chipping and shredding mechanism, and is driven by a hydraulic transmission system. The equipment is powered by a hydraulic motor with a rated power of N_t = 18.36 kW, a working width of B_c = 1.66 m, and a drum diameter of D_r = 0.53 m, rotating at a speed of n_t = 2550 rpm. The combination of the MTZ 82 tractor and the designed equipment demonstrated effective performance on reforestation sites with slopes up to 25%. The productivity ranged from 1.6 to 2.2 hectares per shift for natural shrub vegetation and from 0.35 to 4.2 tons per hour for post-harvest residues such as branches and bark, corresponding to 2.4 to 2.8 hectares per shift. The processed material length varied from 3.0 to 10.0 cm. The equipment is fully domestically manufacturable, cost-effective, and suitable for deployment at forest production units in Vietnam.