1st Edition

Sound and Vibrations of Positive Displacement Compressors

By Werner Soedel Copyright 2007
    368 Pages 198 B/W Illustrations
    by CRC Press

    Positive displacement compressors are the most common type of compressor for commercial applications and among the most important in industrial use. Effective control of noise and vibration stems from a deep understanding of their sources, effects, and behavior in the compressor's various components. Based on more than 30 years of research and practical experience, Sound and Vibrations of Positive Displacement Compressors is the first book to combine theory and design guidelines dedicated solely to compressors.

    After introducing the sound- and vibration-producing mechanisms common to different types of compressors, the author discusses free and forced vibrations of compressor housing shells, mainly for hermetically sealed designs. He then examines vibration in casings and other components, such as suction and discharge tubes, along with surging in coil springs. Detailed chapters explore the design and vibrations of automatic plate or reed valves as well as the analysis and design of suction and discharge mufflers, while the final chapters cover multidimensional acoustics, measurements and source identification, electromotors, and the influence of lubrication oil on sound and vibrations.

    Illustrated by numerous diagrams and several case studies, Sound and Vibrations of Positive Displacement Compressors guides in the analysis and design of compressors for minimal sound and vibration production and suggests various noise control measures.

    INTRODUCTION
    General
    The Compression Process
    Valves
    Suction and Discharge Manifolds and Pipes
    Casing
    Hermetic Housing Shell
    Vibration Isolation Springs
    Oil Sump
    OVERVIEW OF NOISE SOURCE AND TRANSMISSION MECHANISMS BY TYPE OF COMPRESSOR
    Reciprocating Compressors
    Rotary Vane Compressor
    Rolling Piston Compressors
    Scroll Compressor
    Screw Compressor
    NATURAL FREQUENCIES AND MODES OF COMPRESSOR HOUSINGS
    Equations of Motion
    Boundary Conditions
    Natural Frequencies and Modes
    Further Simplification
    Vibration Localization at End Caps
    COMPRESSOR HOUSINGS THAT ARE NOT AXISYMMETRIC
    Mode Splitting Caused by a Mass or Stiffness
    Mode Splitting Caused by Ovalness
    Example of Experimentally Obtained Housing Modes
    MODIFICATIONS OF HOUSING NATURAL FREQUENCIES AND MODES
    Stiffening of Compressor Housing
    The Influence of Residual Stresses
    FORCED VIBRATION OF COMPRESSOR HOUSING (SHELL)
    Modal Series Expansion Model
    Steady-State Harmonic Response
    Housing Dynamics in Terms of Modal Mass, Stiffness, Damping, and Forcing
    Steady-State Response of Shells to Periodic Forcing
    Remarks About Dissipative Damping
    Dynamic Absorbers
    Friction Damping
    FREE AND FORCED VIBRATIONS OF COMPRESSOR CASINGS
    The Three-Dimensional Equations of Motion for an Elastic Solid
    Free and Forced Vibrations
    Steady-State Harmonic Response
    Response of the Casing to Impact
    Steady-State Response of the Compressor Casing to Periodic Forcing
    VIBRATIONS OF OTHER STRUCTURAL COMPONENTS OF A COMPRESSOR
    Vibration and Force Transmission of Discharge or Suction Tubes
    Vibration Isolation Considering Idealized Springs
    Surging in Coil Springs Interfering with Vibration Isolation
    SOUND AND VIBRATION OF COMPRESSOR VALVES
    Remarks About Types of Compressors and Their Valving
    A Simplified Approach to Understanding Valve Design
    Useful Valve Calculations
    Valve Dynamics
    Stresses in Valves
    SUCTION OR DISCHARGE SYSTEM GAS PULSATIONS AND MUFFLERS
    Reducing Valve Noise
    Reactive Mufflers Using the Helmholtz Simplification
    The Continuous System Approach Applied to Tubelike Compressor Suction and Discharge Manifolds
    Typical Behavior of Simple Compressor Suction or Discharge Mufflers
    MULTIDIMENSIONAL COMPRESSOR SOUND
    Three-Dimensional Acoustic Wave Equation
    Sound Radiation from the Compressor Housing (or Casing)
    Gas Pulsations in the Cavity between the Compressor Casing and Housing
    REMARKS ON SOUND AND VIBRATION MEASUREMENTS AND SOURCE IDENTIFICATION
    Rooms for Measuring Sound
    Repeatability of Measurements
    Identification of Sound and Vibration Mechanisms
    MISCELLANEOUS SOUND AND VIBRATION SOURCES OR EFFECTS
    Electromotors
    Lubrication Oil
    REFERENCES
    INDEX

    Biography

    Werner Soedel

    "This book, written by a scientist and engineer of high level and intended for engineers, presents a deep understanding and effective concepts of noise and vibration control in compressors, and thus may be very useful for specialists in the corresponding areas."

    – Yuri N. Sankin, in Zentralblatt Math, 2009