INFLUENCE OF THERMAL DILLATATION UPON DESIGN OF SCREW MACHINES
Close control of the clearances between the rotors and the casing is essential for efficient and quiet oil free compression or expansion in twin screw machines. Differential thermal expansion between these components can therefore have adverse effects, especially when both functions are performed by the use of only one pair of rotors in a single casing. A plain compressor and a combined compressor-expander are analysed and it is shown how good results can be obtained by the use of different materials for each component. The analytical results show good agreement with experimentally derived data.