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Accurate prediction of internal leaks in stationary dry Roots vacuum pumps

✍ Scribed by Laurent-Charles Valdès; Benoı̂t Barthod; Yves Le Perron


Book ID
104266195
Publisher
Elsevier Science
Year
1999
Tongue
English
Weight
321 KB
Volume
52
Category
Article
ISSN
0042-207X

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✦ Synopsis


There exists a calculating method for internal leaks in dry Roots vacuum pumps. It rests upon the semi-empirical Knudsen-Dong law (Knudsen M, Ann Phys 1909;28:75; Dong W, PhD thesis, Contract no. W-7405-eng-48, University of California, 1956) describing steady rarefied gas flows in the three well-known regimes of flow; the only data input is the geometric contour of the stator and the rotors, and the pressure operating conditions. Using readings taken from a stationary dry Roots pump, it is checked that this calculating method is capable of predicting the conductance of each of the clearances to a few percent, on a pressure range widely covering the transient flow regime.