Optimization of working conditions of aspirator used in pneumatic seeding machines

This study was carried out to determine the optimum working conditions of the aspiratör used to create vacuum for holding the seeds on the disc. It was invesitgated to determine the effect of the forward speeds on seed distribution by operating the machine at 1.5 m/s, 2.0 m/s and 2.5 m/s speeds. A domestically produced 4-row pneumatic sowing machine was used in the tests. Vacuum was measured with Cem dt-8890 device, speed measurement with Testo 470 device, sound level with KKMOON GM1352 device, air velocity measurement with Testo 435 device and toughness measurement with HBM-T4A device. Oil The main line of TR 2242 CL variety of unflower seeds, were used in this research. Aspirator speed, vacuum measurments, air speed, noise levels and tractor PTO torque were measured in 5 minutes and 3 repetitions. Rotation speed of the aspirator was measured from the aspirator shaft by Testo 470. Vacuum measurements were made from the vacuum distribution head, inlet of the vacuum chamber and the seeding disc of the planting unit. In order to carry out these measurements, special measurement apparatus were made for the pneumatic seed drill. A plastic cover was made for the measurement from the vacuum distributing head. An additional hose piece was used for the measurement from the vacuum chamber of the planting unit and disc with a single hole were manufactured for the measurement from the seeding disc. Air velocity was measured from the vacuum collector. The noise level measurement was realised by holding the device at ear level. The amount of noise generated during the tests were measured from inside the tractor, in front of the aspirator and just the tractor working without the pneumatic sowing machine. Torque measurement was made from the tractor PTO. A specia chassi was manufactured for fixing torkmeter during tests. The on-row distance of seeds was arranged as 28 cm. Tests were performed in 3 replications on a 3-meter adhesive band conveyor for 15-meter length. Measurements were carried out for 1.5 m/s, 2.0 m/s and 2.5 m/s, 5 times for each repetition. During the trials, the movement of the pneumatic planting machine was provided by the tractor. Since the tractor and the pneumatic seed drill were stationary, a wheeled apparatus was made and placed under the pneumatic seed drill in order to move the movement wheel of the pneumatic seed drill. This apparatus is powered by the hydraulic output of the tractor. Vacuum values varied between 9.14 kPa and 9.41 kPa in the measurement made from the vacuum collector head closest to the aspirator. Values in the vacuum measurement from the entrance of the planter unit to the vacuum chamber were between 8.63 kPa and 9.03 kPa. Vacuum values were determined between 7.31 kPa and 8.80 kPa for the seeding disc with single hole. Vacuum values decreased by 1%-2% as it moved away from the aspirator.The measured value was changed between 71.6 dB and 76.8 dB In for inside of the tractor cabin. The noise level in front of the aspirator was measured between 98.3 db and 116.7 db. The measurement sound level in front of the tractor was measured between 91.9 db and 99.9 db. The highest RPM value was 589.80 rpm for the aspirator shaft and the lowest value was 515.90 rpm.PTO shaft speed was arranged as 540 rpm for tork measurements. The highest value was 60.96 Nm and the lowest value is 22.98 Nm. The acceptable on-row spacing rate was 100% for 1.5 m/s. No twinning and spacing were detected at 1.5 m/s speed. This result shows that the machine was working "very well" according to the test evaluation criteria. The acceptable on-row distance ratio is 97% in total at 2.0 m/s, the twinning rate was 4%, and the spacing rate was 4%. According to these values; the machine results for 2.0 m/s was rated as "good" according to the test evaluation criteria. The acceptable on-row spacing rate is 99% for 2.5 m/s froward , the twinning rate was 2% and the spacing rate was 0%. According to these values, the machine performance for 2.5 m/s speed was determined as "very good". In the research; As a result of variance analysis of the tests performed at 3 different speeds, it was determined that the speed did not have a statistically significant effect on the distance on the row. It has been concluded that the the pneuöatic planting machine can be used at the highest test speed as 2.5 m/s in the research,, without affecting its performance, and in this case, the field work performance will be increased. Keywords: Pneumatic Seeder, Vacuum, Speed, Air Velocity, Sound Level.