PERFORMANCE STUDY OF MACHINES FOR WORKING WITH HOTHOUSE SOIL
Hothouse plant growing based on the organic farming soil technology includes hothouse soil preparation, use, and removal from the hothouse upon the termination of the growing cycle. A complex of machines of new designs, consisting of a combined paver, a loader-mixer and a soil removal machine, is proposed to carry out these works. One of the main efficiency indicators of these machines is their performance Analytical expressions describing the influence of design and operating parameters on the performance of machines were obtained in the course of theoretical studies. The conveyor chain speed, the angular rate of the dosing drum, the number of conveyor scrapers, and drum bars have been determined to have the maximum impact on the performance of the combined stacker, while for the soil removing machine these parameters include the height of the removed soil layer and the machine travelling speed. A series of two-factor experiments have been carried out to define the optimal values of the above parameters. Based on the analysis of the experimental data, regression equations and respective 3D response surfaces have been obtained describing the impact of defined parameters on the performance. For the combined stacker, the following optimal parameter values have been determined, at which its performance reaches maximum value: 0.33-0.37 m/s chain speed, 7 to 8 conveyor scrapers (for the 2.5 m long conveyor); 6.0-6.5 rad/s angular rate and 6 dosing drum bars. The maximum performance of the soil-removing machine corresponds to the following parameters: 0.2-0.25 m/s travelling speed with the dump surface inclination of 22-24 degrees at the removed soil layer height of 0.18 m. Based on the obtained results, the performance of the hothouse soil preparation and removing machines has been determined.