Cross-section view of two pairs of rotating elements, called rotors screw compressor two different profiles is shown in Fig. 5.1. Male rotor here has four tabs and female rotor.six ravines, and this combination of numbers share/ravines is the most common. Other combinations, such 3/5 and 5/7 sometimes available. Another type rotors representing the third dimension is shown in Fig. 5.2.
Some of the popular nominal diameters1 rotors, 125, 160, 200, 250 and 320 mm manufacturers Often offer two or three rotor lengths for each rotor diameter and length-to-diameter ratios, as a rule, does not fall in the range 1.12 1.70. Rotors fit in the housing as indicated in parts, as shown in Fig. 5.3, which also shows that some of the main elements of the compressor.
In separate processes experienced by couples, passing through the compressor (1) the filling of the cavity suction gas, (2) sealing of gas between the rotors and the housing, (3) reduction of the volume of the cavity to perform the compression, and (4) identification of discharge opening in order to banish the compressed gas discharge line.
One of the ways image of these processes, watching a side view of the screws Fig. 5.4 whose threads move to the right, as the rotors turn. Suction pair is in the top of the rotors, and as the rotors turn cavity appears in 1. Cavity 2 continues to fill the cavity and 3 fully completed. Cavity 4 has now trapped gas between the threads, and housing. Cavity 5 is in the process of compression with the volume of jamming as a resonator rests on the end of the body. When the rotor flux reaches the port of discharge, the compressed gas is supplied to the discharge pipe. The translation process is shown in Fig. 5.4, which is the interval, taking place in the period between the cavity are sealed until the compression begins. This translation process takes about 30 rotor rotation.
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