Oil-flooded screw vacuum pumps with a novel flexible discharge port design

Abstract

Industrial oil flooded screw vacuum pumps have two major functions: pulling down and maintaining the required vacuum level. As a result of the two major functions, the screw vacuum pumps have to handle a great range of pressure ratios. A screw vacuum pump with a fixed volume ratio is going to have either the over compression during the pulling down process or the under compression during the required vacuum level maintaining. This paper presents oil flooded screw vacuum pumps with a patented flexible discharge port. Such a screw vacuum pump has its volume ratio or discharge port matched with the real pressure ratio. The most under-compression and over-compression are eliminated, and the vacuum pump noise level is reduced. The design and optimization techniques of the flexible discharge port of a screw vacuum pump are discussed in this paper, and the measurement results of a screw vacuum pump with the flexible discharge port are presented. At typical industrial vacuum levels, a crew vacuum pump with the flexible discharge port design can reduce the power consumption by about 20%.