Values to know for the oral exam

Pagina 1

WATERJET DATA • Reverse osmotic pressure: 0,3Mpa • After the water treatment I have 95% less particles and impurities in the water • With direct pumping: − 3 pistons that rotates with a shaft of 120° − We can reach tens of MPa − If power is higher than 3kW → too expensive • Oil pumping use a three-phase asynchronous motor with 380V and 50Hz of alternative current • Electric pumping uses brushless motor • Intensification factor between 20-40 • Diameter of the transportation tubes is 2-3mm • Volume of the accumulator is 2-3 litres • Compressibility of water at 400MPa: 12%-15% • Focusing nozzle length: 50-100mm • Cutting head diameter for abrasive suspended waterjet: 4mm Orifice diameter Pressure Jet velocity Focusing nozzle diameter Pure waterjet 0,08-0,2 mm (slide) 0,05-0,5 mm (book) 200-300 MPa 700 m/s 0,76-1,2mm Abrasive waterjet 0,2-0,33 mm Up to 400 MPa 1mm ULTRASONIC DATA • Amplitude vibrations: 10-6-10-4 mm • Grain size for finishing processes: 5 − 20𝜇𝑚 • Grain size for coarse processes: 20 − 150𝜇𝑚 • Roughness: 0,5 − 0,76𝜇𝑚 • Alternative current between 50-60 Hz • Vibration frequency between 20-40 kHz • Efficiency of piezoelectric material is 95% • AC power generator • Magnetostrictive materials: − Permalloy − Permentour − Alfer − Hypernik • Less than 1 sec to perform an ultrasonic welding • With ultrasonic welding we can weld sheets with thickness of 2-3mm PLASMA DATA • DC power generator • Current: 15 − 400 𝐴 • Pressure of the primary gas: 1,4 𝑀𝑃𝑎 • Current in the tungsten inner gas: 200 𝐴 • Cutting speed improved due to the air: 25% • Depth of the waterjet configuration: 75𝑚𝑚 Piezoelectric Magnetostrictive Amplitude 5-25𝜇𝑚 - Mass 1kg (low) 9kg (high) Voltage 1kW (low) 5kW (high) Current Alternate AC Alternate AC in the main nucleus DC current in the two nuclea…