Section 1: Types of Air Compressors

 

The first section of the book gives you a summary on themain types (reciprocating, rotary screw, centrifugal) of compressors. This includes tips and comparison charts to help you determine which typewould be best for your application.

 

 

Introduction

           Consideration When Selecting a Basic Type ofAir Compressor

           Duty Cycle/Quality of Air Pressure

           Space and Location/Primary Power

Positive Displacement

           Reciprocating

           Oil Cooled Screw & Vane

           Single Screw

           Water Jacket - Rotary Vane

           Non-Lube Screw and Lube

Dynamic Compressors

           Centrifugal

           Axial Flow

Comparison Charts

           General

           Lubricated

           Non-Lubricated

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Section2: Lubricant Cooled Rotary Screw Compressors

 

This section is a short course on oil cooled rotary screwcompressors including the details on how each component operates. Also, you will find advice about installation and energy recovery as wellas how to trouble shoot the most common problems.

 

 

 

Basic Profile Design and Operating Parameters

           Blow Hole/Thermal Expansion

           Compression Cycle

General Performance Curves

Profile Types - Symmetrical -Asymmetrical

High Performance

Bearings

Terminology

Application and Installation Tips

           General

Capacity Ratings, Duty CyclePressure - Controls

Air Cooled Installation

Water Cooled Installation

Heat Recovery - Cold WeatherOperation - Outdoor

Intake Air

General Piping

Operating with ReciprocalCompressor

Wiring and Power Considerations

Oil Carryover

Synthetic Lubricants

Effect of Altitude

Rotary Screw Installation Tips

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Section 3: LubricantFree Rotary Screw Compressors

 

This section covers the unique aspects of the rotary screwcompressors that provide non lubricated compressed air.

 

 

Introduction and Background

Operating Characteristics

Applying the Lubricant Free Rotary Screw

Comparing Lubricant Free Rotary Screw to Lubricant CooledRotary Screw

Altitude Operating Pressure Chart

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Section 4:  CentrifugalAir Compressors

 

This is dedicated to the centrifugal style of compressor.

 

The design and operating data in this section provides aexplanation of how a centrifugal compressor works.  In addition, there is a check list for the criticalmaintenance issues, specific details on the proper piping installation anddetails on the impact of surge.

 

 

 

Basic Design and Operating Parameters

Impellers

Basic Operation

Diffuser

Inlet Control

Inlet Guide Valves

Application and Installation Tips

Flow Limitations, Surge and Choke- Stonewall

Effects of Cold Air, Capacity andEnergy

Effects of Hot Air, Capacity andEnergy

Basic Maintenance &Installation Considerations

General Maintenance Guidelines

General Piping Guidelines

           Inlet Piping

           Bypass Piping

           Discharge Piping

           Check Valves

           Expansion Joints

Operating in Parallel withReciprocating Compressors

Condensate Drains

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Section 5:  Centrifugal and Lubricant Free Rotary Screw Compressors as used inManufacturing Plants

 

This sectiondiscusses the relative appropriateness of using centrifugal and lubricant freerotary screw compressors for primary air supply in manufacturing plants.

 

 

Background, Replacingthe Old Large Reciprocating Compressors

Development ofLubricant Free Rotary Screw, Sizing and Re-Sizing

Centrifugal Sizing

Comparing the BasicOperating Characteristics

Air End Repairs andReplacement

Basic Packaging

Running LubricantFree Screw as Trim Unit with a Centrifugal

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Section 6:  Compressor Capacity Controls and Energy Cost and Other Energy RecoveryOptions

 

This section illustrates how compressor controls effectthe power cost for operating a reciprocating, rotary screw and centrifugalcompressors. 

 

You will find tips on maximizing the efficiency of powerusage by matching the compressor type to a specific application. There are articles about calculating the price of compressed air as wellas providing ideas for saving money on your power costs.

 

 

 

An Evaluation of Compressor Capacity Controls and TheirEffect on Power Cost

Basic Types - Pros and Cons

Power vs. Capacity Curves

Various Controls

Table - Operating Band vs. ActualCFM, Load Various Controls

Blow Off Controls

Effective Storage Volume andEffect on Cycle Energy

Case Study - ExcessInterconnecting Piping Back Pressure

Case Study - Piping Back Pressure- Precludes Efficient Reciprocating

           Compressor Trim Utilization

Case Study - (2) CentrifugalCompressors Forced into “Turn Down” by

           Piping Back Pressure

Impact of Capacity Controls onYour Input Energy

Typical Standard and PremiumEfficiency Motor Curves at Constant

           and Variable Speed

Variable Speed Drive on Rotary Screw Compressors

Reciprocating Capacity Controls

Rotary Screw Capacity Controls

Centrifugal Capacity Controls

Performance Curves – All Types Compressors – VariousControls 

Profits from a Level I Compressed Air Audit

           Running a Compressed Air Energy Survey

           Recovering Energy Costs in a Compressed AirSystem

Comparing Energy Costs - Electric, Natural Gas, Diesel

Converting Heat Recovery into Energy Cost Savings

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Section 7:  DeterminingYour Air Requirements

 

The information in this session will help you determineyour existing and future compressed air requirements. 

 

This is the starting point to making decisions aboutadding compressors, implementing leak detection programs, installing airreceiver tanks and upgrading compressor control systems.  The engineering formulas and practical examples will save youtime and money by giving you the tools to clearly understand the capacity ofyour air system.

 

 

Introduction

           Compressibility of Air - Pump Up Formula

Determining Your Air Demand

Checking Existing Capacity

Additional Air to Bring System Up

Cost of System Leaks

Sizing Receivers for Surge

Tips for Pneumatic CylinderSelection, Air Tools, Sandblasting Selection

Chart Air Usage - Air Cylinder

CFM vs. Pressure for VariousOrifices

The Compressed Air Receiver - The Endless Question

The General Use and Location ofAir Receivers

Controlling Flow Rate Pulses -Dust Collector

Storage to Offset RegulatorAction Delay

Higher Pressure Off Line Storageto Support Large “Event Uses”

Point of Use Receiver withBooster for Higher Pressure

Typical Dimensions Vertical AirReceivers

Lifting the Fog Surrounding “Demand Side Control”

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Section 8: TheCompressed Air Distribution Systems

 

The focus of this section is on the compressed airdistribution system.

 

This is where you will find ways to save money on thesystem for delivering the air to the points of use throughout your plant. This section explains the high cost of turbulence in air piping with 4case studies.  There are otherspecific examples concerning the cost of common piping mistakes. In addition, there are charts for pressure loss in various pipe sizes andtips for piping for reciprocating, rotary screw and centrifugal compressors.

 

 

 

Introduction - Central or Departmental

Suction Pipe (Large Reciprocating)

Aftercooler

Air Receiver

Drop and Drip Legs

Pipe Slope

Controlling Pressure Loss

Typical Pressure Drop Chart

General Rules for Compressed Air Distributor System

General Tips on Piping

           Inlet - Rotary Recipient

           Discharge - Rotary Recipient

           Guidelines - Material

The High Cost of Turbulence in Air Piping

           Four Case Studies

Pressure Drop in Compressed Air Hose

           Pressure Drop Charts for Pipe ½” to 24”and Normal Fittings

           Pressure Loss Chart to 10,000 CFM to 400 psig

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Section 9:  CompressedAir Dryers

 

This section provides details on getting the moisture outof a compressed air system. 

 

It provides the facts about dew point and the potentialsources of moisture.  You will findinformation on the different types of compressed air dryers including tips onhow to select the most cost effective dryer for your application.

 

 

 

Introduction

           Moisture, Where it Comes from Dew Point,Pressure Dew Point, Relative

                       Humidity, Effect of Temperature Degree ofRequired Dryness

Type of Dryers

Deliquescent Air Dryers

           Absorption, Chemical Process, DryingCapability, Type of

           “Desiccant”, Advantages, Disadvantages,Typical Installation

            Layout

Desiccant Air Dryers

           Absorption, Regenerative Type, Basic Operation,Types of

           Desiccant, Advantages, Disadvantages, Purge Air

Internal Heat Reactivated

           Basic Operation, Purge Requirements

Heat Less or Pressure Swing

           Basic Operation Principles, Purge Requirements         

Purge Control System

           Definition of “How They Work”, PotentialSavings, “Skip Cycle”,

           “Varying Purge Rate”, Capacedence Probes,Temperature Probe,

PDP Measure,Purge Control Savings in Electric Power Dollars

Other Types of Desiccant Dryers

Blower Purge Dryers

Split Stream Dryer

External Heated

Heat of Compression

Solid or Immobilized Desiccant

Single Tower

Energy Cost Comparison

           Heat Less, Ext. Heat, Blower Purge

Refrigerated Air Dryers

           Direct Expansion

                       Non-Cycling, Two Stage, Basic Performance, AirFlow, Refrigerant

                       Flow

           Clean Air Act of 1990

                       Effect on Refrigerants, Equipment, User, Future

           Other Types of Refrigerated Dryers

Heat Sink or Thermal MassCycling Type

Water chiller - Refrigerant

Other “Cycling Dryers”

           Operating Power Cost for Refrigerated Dryers

                       Cycling vs. Non-Cycling

                       Energy Cost Comparison - Pressure Drop

                       Typical Refrigerated Dryer System

                       Air Cooled Aftercooler Location CTD (RotaryScrew)

                       Dew Point and Energy in Refrigeration Dryer

           Membrane Compressed Air Dryer

                       How They Work - Design Capabilities

           General Data

                       Basic Dryer Piping Schematic

                       Atmospheric Vs. Pressure Dew Point, Effect onAftercooler

           Sample Data Required for Application

                       Deliquescent

                       Refrigeration

                       Desiccant

                       General Selection Guidelines

                       General Piping Guidelines

                       Dew Point Conversion Charts, Refrigerated,Desiccant

                       Dryer Combination

                       Conversion Table - Water Content of Air

                       Other Means of Moisture Contamination

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Section 10:  Aftercoolers,Separators and Compressed Air Line Filters

 

This section covers the products that are used to filtercontaminants from compressed air.

 

The information explains how the pressure loss associatedwith filters will increase the energy cost to produce compressed air. There are tips on how to pick the best filter for your requirementwithout building in extra annual expense in wasted energy. 

 

 

 

Aftercooler/Separator Overview

Separator Performance

Mechanics of Filtration

Particulate Filters

Coalescing Filters

Absorption Filters

Comparing Filter Performance

Instrument Air

Breathing Air

Medical Air Filters

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Section 11:  AutomaticCondensate Traps

 

Ways to save money with condensation drains.

 

This section makes it clear how much energy is beingwasted by using many of the most common types of drains.  The knowledge of where money is being wasted can be used todemonstrate the potential for savings in your plant.

 

 

Introduction - Energy Cost of Leaks

Float Operated Traps

Electronic Auto Drains

           Valves - Internal Pilot

           Floating Seal

           Motorized Ball Valve

Energy Cost - Lost Air with Dual Cycle Electronic AutoDrains

Level Actuated Electronic

Chart - Condensate Generated per CFM (H.P.)

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Section 12:  CompressedAir Condensate Oil Water Separation

 

The facts about oily water condensate.

 

This section includes an overview of the regulations andprovides an explanation of the various devices used to treat the oily watermixture.  There are also tips onwhere the savings can be found in the treatment of the oily water condensate. 

 

 

 

Introduction - Overview

           Basic Regulations, Responsibility

Gravity Separators, Carbon After Filters

Gravity Pre-separation with Coalescing Filters and CarbonAfter Filters

Membrane Separation

           Ultra Filtration

           Micro Filtration

Distillation

Types of Compressor Lubricants Related to Separation

Energy Cost Comparison of Various Distillation Methods -Steam, Natural Gas,

           Electricity, Heat of Compression

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Section 13: AirCompressors for Altitude Operation

 

High altitudes have an effect on a compressed air system.

 

This section gives you the specific impact on thedifferent types of air compressors, air tools and air motors when operating inhigher altitudes.  You will find theconversion factors for determining the performance levels you can expect.

 

 

 

Introduction - Terminology

Effect on Altitude

           Reciprocating

           Rotary Oil Cooled

Other Effects of Altitude

           Air Tools, Air Motors

           Boiling Temperature

           Engine Horsepower

           Electric Motors

Steps to Set Up Altitude Air System

 3

 

Section 14:  SyntheticCompressor Lubricants

 

Saving money with synthetic lubricants.

 

This section explains which compressor type can benefitfrom the different synthetic oils on the market. In addition, you will find advice on how to get the most from a regularoil analysis program.

 

 

 

Types of Compressors and Their Use of Synthetic Lubricant

Oil Analysis as a Maintenance

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Section 15:  HighPressure Air

 

This section explains the fundamentals of high pressureair which is usually considered anything over 250 psig.  You will find information regarding the use of reciprocatingcompressors as well as the potential for using a booster compressor. Also, there are case histories that give some insight on the safetyconcerns when using high pressure compressors.

 

 

 

Definition of High Pressure

Reciprocating Compressors

Determining Temperatures and Ratios

Tables

           Adiabatic Temperature vs. Ratio of Compression. Sample Single Stage,

                       Double Acting Booster

Use of a Booster

           Sizing of Booster - Inlet Pressure, DischargePressure, Ratio, Capacity,

                       Horsepower, Power Saving

Safety in High Performance Air

API Standard 618 Third Edition

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Section 16:  Optimizingthe Compressed Air System

 

Optimizing your compressed air system.

 

This section deals specifically with the high cost ofcompressed air.  It provides insighton the opportunities to save energy by managing the compressors, air treatmentequipment, piping systems and the demand side. You should understand this information before considering an air audit.

 

 

 

Definition - Optimum Compressed Air System

Cost of Compressed Air

Effective Management of Compressed Air

Supply Side Management

           Types of Compressors, Controls, MotorEfficiency, Pressure Drop in

                       Filters, Dryers, etc.

Waste Management

           Leak Control, Auto Drains

Demand Side Management

           Pressure Spikes, Flow Control, Lowest EffectivePressure

 back

 

Section 17:  FlowMeasurement

 

It is helpful to know the air flow in CFM to trouble shoota problem or to determine if more compressors are needed in a plant. However, there are many instances each year when decisions are made basedon incorrect or misinterpreted data taken from flow meters. This section provides details on the operation of the main types of flowmeters. 

 

 

 

Field Measuring Compressed Air Flow

Flow Reading Charts

Differentials

What is the V Cone?

Inline Flow Meters?

Vortex Shedding

Thermal Mass Flow

Commercial Flow Sensor

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Section 18: RunningA Leak Survey

 

A leak management program can add energy savings to thebottom line.  This section coversthe basics of a leak survey and how to determine the cost of compressed airleaks.  It also includes adiscussion on ultrasonic leak detection.

 

 

 

Source of Waste

Common Problems

Finding Leaks

Bleed Down Test

Ultrasonic Detection

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Section 19: Terminology& Technical Support

 

The final section gives you a summary of terms and morethan 30 charts on issues relating to compressed air.  This information is a resource that can be referred to foryears to come.

 

 

Terminology, Definitions, Rules of Thumb, Helpful Formulas

           Conversion Factors

           Conversion Chart - Inches/Decimal/Metric

           Terminology, General Terms

Useful Formulas

           What is CFM, ICFM, ACFM, SCFM

Rules of “Thumb”         

Water Cooled Aftercooler

Compressor Discharge Temperature

Horsepower to Pressure -Horsepower to Power Cost

Electrical - Horsepower toAmperage

Heat Rejection

Ventilation Required

Horsepower per CFM per PressureReading

Piston Speed

Apply 60 Hz Motor to 50 HzApplications

Time, Capacity to Draw Vacuum

Install Compressor - Intake toCoolest Location, Effect on Efficiency of

           Dirty Intake Filter

Cylinder Clearance andCompression Ratios Effect on Volumetric

           Efficiency - Reciprocating Compressors

Oil Carryover

Centigrade to FahrenheitConversion Table

Air Cylinder Chart

Single Phase and 3 Phase ElectricMotor - HP to Volts to Amps

Miscellaneous Electrical Formulas(Shaft BHP to Input Kw)

Vertical Air Receiver

Storage Volume of Piping

Electrical Energy Cost per CFM,per PSIG

Weight of Dry Air

Barometric Pressure vs. Altitude

Water Content of Air

Dew Point at Pressure

Calculating Velocity ofCompressed Air in Pipe

Discharge Air Through OrificeTable

Air Flow Table

Flow of Air Through OrificesUnder Vacuum

Pressure and Vacuum Equivalents

Conversion Factors

Decimal and Metric Equivalents - fractions of an inch

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