Operation and Design of Claw Vacuum Pumps (190,00 руб.)

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UDC 621.521 Published by the decision of the Editorial Review Board of the Kazan National Research Technological University Reviewers: Doctor of Physical and Mathematical Sciences P. Osipov PhD in Engineering E. Kapustin Raykov A. Operation and design of claw vacuum pumps : monograph / A. Raykov, S. Salikeev, A. Burmistrov; The Ministry of Education and Science of the Russian Federation, Kazan National Research Technological University. – Kazan : KNRTU Press, 2022. – 168 p. ISBN 978-5-7882-3161-7 The monograph focuses on the design variations of oil-free vacuum pumps and their pumping characteristics. It describes computational procedures of working processes for volume displacement pumps and the mathematical model of working process for an oil-free claw vacuum pump. The monograph describes the experimental study of pump characteristics and presents indicator and temperature diagrams. The gas flow in the pump inlet and outlet ducts is studied both mathematically and experimentally. The influence of the pump configurations on the pumping characteristics is analyzed. The monograph is designed for students majoring in Vacuum Engineering for the courses “Rotor machines” and “Dynamic machines”. The monograph was developed at the Department of Vacuum Engineering. UDC 621.521 ISBN 978-5-7882-3161-7 © A. Raykov, S. Salikeev, A. Burmistrov, 2022 © Kazan National Research Technological University, 2022 2

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CONTENT LIST OF REFERENCE AND TERMS ............................................................... 5 INTRODUCTION ............................................................................................ 7 Chapter 1. OIL-FREE VACUUM PUMPS ..................................................... 11 1.1. ROOTS VACUUM PUMP .................................................................................... 15 1.2. CLAW VACUUM PUMP ...................................................................................... 20 1.3. SCREW VACUUM PUMPS .................................................................................. 34 1.4. SCROLL VACUUM PUMPS ................................................................................ 38 1.5. SUMMARY ......................................................................................................... 42 Chapter 2. EXPERIMENTAL STUDY OF CVP ............................................ 44 2.1. SUBJECT OF RESEARCH DESCRIPTION ............................................................ 44 2.2. GAUGES SELECTION FOR READING INDICATOR DIAGRAMS .......................... 47 2.2.1. Strain-gauge method ............................................................................ 48 2.2.2. Piezoelectrical method ......................................................................... 51 2.2.3. Capacitive method ................................................................................. 55 2.2.4. Resonant method ................................................................................... 56 2.2.5. Inductive method ................................................................................... 57 2.3. THE EXPERIMENTAL TEST UNIT DESCRIPTION .............................................. 62 2.4. TEST OPERATION PROCEDURE ....................................................................... 66 2.5. MEASUREMENT DATA PROCESSING ............................................................... 72 2.6. RESULTS AND DISCUSSION ............................................................................. 77 2.7. FLOW RATE FACTORS INDICATION FOR CVP INLET AND OUTLET DUCTS ....................................................................................................................... 80 2.7.1. Test unit and measuring technique .................................................. 81 2.7.2. Data processing ...................................................................................... 85 3

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Chapter 3. MATHEMATICAL SIMULATION OF CVP WORKING PROCESS ...................................................................................................... 96 3.1. STATE-OF-THE-ART ON FUNDAMENTAL AND EXPERIMENTAL RESEARCH OF CVP AND OTHER STRAIGHT-TOOTHED PUMPS ............................ 96 3.1.1. Simulation of the working process of non-contact vacuum pumps .................................................................................................... 99 3.1.2. Gas flow simulation in complexly-shaped channels ................ 101 3.2. FUNDAMENTALS AND BASIC ASSUMPTIONS ................................................ 105 3.3. MATHEMATICAL MODEL OF CVP WORKING PROCESS ............................... 106 3.4. PUMPING SPEED COMPUTATION .................................................................. 108 3.5. THE WORKING CAVITY GEOMETRY ............................................................... 109 3.6. SUCTION AND DISCHARGE PORTS CONSTRUCTION .................................... 119 3.7. GEOMETRICS OF THE PUMP UNDER STUDY ................................................. 121 3.8. DESCRIPTION OF CALCULATION ALGORITHM OF GAS LEAKAGE THROUGH ROTOR MECHANISM CLEARANCES ...................................................... 127 3.8.1. Dependency of channels geometry features vs rotors rotation angle .................................................................................................. 127 3.8.2. Calculation procedure of leakage via slot channels ................. 133 3.8.3. Leakage integration by gas stream directions ........................... 135 3.8.4. Thermal deformations allowance ................................................... 136 Chapter 4. MATHEMATICAL SIMULATION RESULTS AND ANALYSIS OF GEOMERTICS INLUENCE ON WORKING PROCESS ................................................................................................... 138 4.1. COMPARING EXPERIMENTAL AND THE CALCULATED DATA ....................... 138 4.2. ANALYSIS OF GEOMETRICS INFLUENCE VS WORKING PROCESS ................ 143 4.2.1. Clearances of rotor mechanism ...................................................... 143 4.2.2. Discharge port length ........................................................................ 145 4.2.3. Rotor tooth thickness ......................................................................... 151 4.2.4. Center-to-center spacing and the casing bore radius .............. 153 CONCLUSION ............................................................................................ 157 BIBLIOGRAPHY ........................................................................................ 158 4

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