Автор: Dimitar Peev
Статии
- EXPLOITATION RESEARCH OF A CABLE SKIDDER TAF 690 PE FOR TIMBER SKIDDING IN THE WESTERN STARA PLANINA
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Резюме
This paper presents the results of a study that was conducted to establish the basic performance characteristics of a specialized forestry tractor for skidding of a whole tree stems and long timber sections in mountainous conditions. The tractor travel speed at different gradients as well as the hourly productivity for a tree-length harvesting system in the Western Balkan Mountains region were determined. The regression analysis method was used to conduct the study and to determine the influence of various factors on the hourly productivity of the tractor, at a constant trip load volume. For this purpose, a planned two-factor experiment with three levels of variation of input factors was conducted. The time for tractor’s moving in different gradients was determined by timing. Running speeds were found at range from 3,23 to 4,82 km/h, hourly productivity from 5,36 to 10,98 m3/h with trip loads ranging from 6,9 to 8,5 m3. Regression equations were derived and by their use could be determined the productivity for different gradients and different lengths of skidding distances.
Ключови думи: cable skidder, skidding wood, speed of skidding, hourly productivity
- TECHNOLOGICAL RESEARCH OF PNEUMOSEPARATOR FOR FOREST SEED EXTRACTION
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Резюме
A technological study on the operation of a pneumatic separator on a BCC Cleaner&Seed Sizer (mini) machine for extraction of Scots pine (Pinus sylvestris L.) seeds has been carried out. It is part of the new technological equipment for greenhouse production of container seedlings in the Lokorsko forest nursery. Compared to the traditional production of saplings in Bulgaria for afforestation, the new production requires the extracted seeds to have higher quality indicators. In order to establish the optimal operating modes of the pneumoseparator for high quality seed production, with minimal seed losses in the waste in the aspiration system, a multifactor active experiment and optimization in the treatment of Scots pine seeds was conducted. The obtained results were used to establishment of a regression models to predict the technological parameters and the quality of the obtained seeds depending on the operating modes of the machine. The optimal parameters for setting the pneumatic separator have been established and functional modes for Scots pine seeds extraction have been determined.
Ключови думи: pneumoseparator, scots pine seeds, quality, models, optimization
- REGRESSION MODELS FOR DETERMINING THE OPERATING COSTS OF FORESTRY MILLING MACHINES FOR COMPLETE SOIL PREPARATION FOR REFORESTATION OF POPLAR CLEARINGS
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Резюме
This paper presents the results of an experimental study conducted with a self-propelled milling unit PT-400 with a multifunctional forestry milling machine FAE 300/S-225 for complete soil preparation for reforestation of poplar clearings. Regression models were developed to determine the relative fuel consumption and time consumption for complete soil preparation of poplar clearings. Based on the obtained results, the influence of the speed parameters of the forestry cutters and the working conditions in the fellings on the size of the operating costs was determined. Of all the factors that express the conditions of work, the diameter and density of the stumps have the greatest weight and dominance on the cost indicators. The amount of shredded shoots, bushes and wood waste ranks third, and the mechanical composition of the soil has the least influence. To mitigate the impact of more severe working conditions, it is best to use the cutter's "rotational frequency" factor. Regardless of the type of technological operation performed, lower operating costs are obtained at a higher frequency of rotation of the cutter. Given that this factor can be managed within wider limits, it is recommended that forestry cutters for shredding stumps and roots and mulching wood waste, shoots and bushes, operate at a higher frequency of rotation of the rotor – over 500 min-1.
Ключови думи: relative fuel consumption and time, stump diameter and density, speed