Brit Thielemann Product Manager - Stationary Air Products Sullair
Who Cares About Compressed Air?? Compressed Air Equipment Suppliers? Production Floor Personnel Downtime Product Quality Cost of Air Maintenance Uptime Complaints Management All of the above Your Utility Company!
Today s Presentation We will review: - Compressors - Dryers - Filtration - Costs of Compressed Air
Types of Compressors Reciprocating Piston Single Acting Double acting Rotary Screw - Oil Flooded & Oil Free Lobe Sliding Vane Scroll Centrifugal Axial
Reciprocating Single Acting Double Acting
Rotary Screw Single Stage Oil Fee Two Stage Oil Flooded
Centrifugal Compressor
Compressor Selection Guidelines Many factors come into deciding on what type of compressor you need!
What to look for in a compressor selection Reliability Durability Product Features Warranty Initial Cost Life Cycle Cost After Sales Support Relationship Return on Investment
Compressor Controls and the System
Control Types Start / Stop Function» Controlled by Pressure Switch Settings» Compressor runs On or Off Application» Reciprocating / Rotary Screw Load / Unload (motor continues to run inlet valve open and closes) Function» Controlled by Pressure Switch» Compressor runs either Loaded or Unloaded Application» Reciprocating / Rotary Screw / Centrifugal
Control Types Modulating Function» Reduces compressor output by restricting inlet flow Application» Rotary Screw / Centrifugal Variable Displacement Function» Allows progressive reduction in compressor displacement without reducing inlet pressure Application» Reciprocating ( Multi Step ) /Rotary Screw ( Spiral/Turn Valve )
Control Types Variable Speed Drive ( VSD ) Function» Adjusts compressor capacity output by controlling Motor Speed Application» Rotary screw Inlet Throttling/Inlet Guide Vanes (IGV) with Blow Off Function» Like Modulation Inlet Throttling controls the capacity of the air compressor by reducing air flow into the compressor» After minimum turndown is reached Blow Off occurs relieving excess capacity to atmosphere Application» Centrifugal
Control types Reciprocating Compressors - 3 Step Unloading - 5 Step Unloading Other Rotary Controls - I-R ACS Control Centrifugals - Inlet Throttling - Inlet Guide Vanes - Blow Off
Control Comparison Which control type is best?? Answer it depends
Variable Speed Drive Excellent Energy Savings Stable System Pressure Consistent Product Quality Reduction in System Storage Requirement Lowering Air System Leaks Increased Start / Stop Capability Flexibility to Grow in Future Attractive Life Cycle Cost Potential Rebate from Utility Company
Varible Speed Drive - Limitations Environmental Concerns Temperature Limits Moisture (Water, Rain, Condensation, Snow) Dust, Dirt, Contaminants Electrical System Power Quality Additional Complexity Full Load Losses Must be Properly Applied
Controls Conclusion Understand the type of controls on your air compressor and how they operate Assure that the controls on your compressor are setup and operating per design Understand their minimum efficient turndown in your system Avoid Load Sharing - in most circumstances
Compressor Room Layout and Design Considerations
Compressor Room Layout What are the connections that need to be made to the compressor? What other considerations should be made regarding compressor inputs and outputs?
Compressed Air Inputs and Outputs
Compressed Air Inputs and Outputs Discharge Compressed Air Condensate Removal Intake Air Electrical Input Heat Removal Exhaust Cooling Water
Start at the Inlet Question? Where should the intake air come from? Answer: The cleanest, driest, coolest place possible. Each installation should be evaluated individually. The quality of intake air directly effects the performance and longevity of the compressor.
Inlet Considerations Clean air - Avoid particulates - metal, wood, abrasives, etc. - Avoid fumes - chlorine, battery acid, chemicals, etc. Cool air - Effects operating temperature - Effects capacity - Effects condensate Dry Air - Effects capacity - Effects condensate
Installation Size per NEC or manufacturers recommendations Motor Starters On unit Remote Included Most compressors single point Sequencing/Communications Auxiliary items - Drains, remote coolers, oil pumps, etc.
How to cool? Water Cooled - City water (avoid if at all possible) - Cooling tower (Open Evap, Closed Loop, Closed Loop Evap) - Chilled Water - Closed loop cooling with Trim cooler Air cooled - Cooler on unit - Remote cooler All have unique costs and reliability issues
Heat Removal Air Cooled - Cooler on Unit/Remote Cooler - Exhaust - Ductwork - Heat Recovery Water Cooled - Supply and Return» City Water - Chilled Water (avoid)» Tower Water - Closed Loop Cooler - Gauges temperature and pressure - Valving - Controls
Typical Cooling Data for Air Compressors Note:Consult with manufacturer for specific machine data. All values assume compressor at full load.
Air Cooled or Water Cooled- which one? Water Cooled - Dirty environments - High ambient temperatures - When noise is an issue - When removing heat from compression is a problem Air Cooled - Cooling water not available/unreliable - High water costs/chilled water costs - When heat recovery can be used - Simpler installation - Low ambient temperatures
Heat Recovery Excellent opportunity for energy savings Thermostatically controlled Must have high static fan to work well Remember make up air Avoid fans in series Don t overcool the compressor in winter Purchase manufacturer s package if available
Clearance Considerations 3 feet minimum all sides Electrical Clearance per NEC Overhead Clearance minimum of 4 feet Air cooled cooler discharge At least 6-8 feet Direction Filter separator removal clearance Removal/replacement of unit and major components
Other Considerations Ambient Temperature between 40 to 90 F Place to install emergency compressor - valved and capped. (Rental diesel or electric) 65% of the water in the air system is removed at the air compressor aftercooler Floor Drains/Floor Trench Noise 65 to 100 db Enclosure? Maintenance Noise Environment
3 Valve Bypasses Where and Why? Air dryers Filters Receivers Flow control devices Any where service is required and the plant must be shut down without it!
What s in your Air?? Water Dust Particles Bacteria Microorganisms Pollen Hydrocarbons Industrial acids Remember your neighbors!
Air Drying-Types Refrigerated Desiccant Deliquesent Membrane
Refrigerated Air Dryers 1) Refrigeration & Separation (Refrigerated Dryers) - Air is cooled causing water to condense into a liquid. - The liquid is removed using a water separator. Advantages - No air loss Disadvantages - Minimum 33 o F dewpoint Cooling Separation
Refrigerated Air Dryer / Non Cycling & Cycling Typical Dewpoint Achieved / 50 Degrees
Desiccant Air Dryers Typical Dewpoint is -40 degree (-100 degree possible)
Heatless Desiccant Dryer Heatless - A portion of the dry compressed air is expanded to atmospheric pressure, reducing moisture content even further. This very dry air is then passed backwards over the desiccant bed removing the moisture it had previously collected, and released to the atmosphere. Total purge air required is approximately 15% of the rating of the dryer.
Heated Desiccant Dryer Alternately, the desiccant can be heated to get it to release the moisture it is holding. It must be cooled before it can be used for drying again. Externally Heated Expanded dry compressed air is used for both heating and cooling. Total purge use is reduced to 7%. Blower Purge Ambient air is used for heating, expanded dry air is used for cooling. Total purge use is reduced to 3% (averaged over time). Heat of Compression Heat from the air compressor is used to regenerate the bed. No purge Air is lost.
Deliquescent Dryer / Absorbtion type
Deliquescent Dryer / Absorbtion type Absorption (Deliquescent Dryers) Air is passed over a sacrificial catalyst which chemically reacts with the water molecules. Advantages No air loss. Disadvantages Corrosion & cost of catalyst.
Membrane Dryers Membrane Filtration (Membrane Dryers) Air is passed through a membrane which allows air through, but blocks water molecules. Advantages No electricity required (Point of Use) Disadvantages High Purge Loss & susceptibility to oil.
Membrane Dryers
Filtration ISO 8573.1 Quality Classes
Filter Media Types Entrapment - Solids - Particles are either larger than the holes in the filtration media, or they impact it. Coalescing Liquids - Tiny droplets coalesce into larger drops and are pulled out by gravity. Adsorption - Vapors (Carbon) - Molecular attraction between the contaminant and the filter media **Size appropriately and watch out for pressure drop**
Particle Size The smallest particle visible to the naked eye is approximately 40 microns in diameter. Typical filters remove particles as small as 1/100 th of a micron.
Results of inadequate air treatment Corrosion Freezing Equipment wear & failure Product spoilage Bacteria and mold growth Maintenance costs Production down time Unhealthy working environment
The Cost of Compressed Air
Why do we care about the energy costs of compressed air systems? COMPRESSED AIR IS FREE, RIGHT??? 50
Energy Savings Potential from Compressed Air System Improvements Conservative Estimate Of Energy Savings 90 Billion kwh in U.S. consumed by compressed air systems annually x $.06 per kwh national average energy rate $5.4 Billion annual electrical costs x 15% - 60% average savings $810 M - $3.2 B in potential savings in U.S. markets According to the U.S. Department of Energy: 90 billion KWh of electricity is consumed annually by compressed air systems. According to industry experts there are savings opportunities from 15% to 60%!!! 51
Compressed air, considered industry s fourth utility, is often a significant cost of production 10% of all electricity consumed in the US is by compressed air systems 1 16% of all motor system energy consumed in the US is by compressed air systems 1 A typical compressed air system wastes 50% of the air produced providing a tremendous opportunity to reduce production costs Leaks 25% Artificial Demand 15% Poor Practices 10% Production 50% More Air is not the Answer! 1. Data from the U.S. Department of Energy 52
Why does this Opportunity exist? Most plants do not understand their compressed air system and do not know: What their compressed air really costs? What pressure they really run at? What pressure they need? How much cfm they really need? How much cfm they waste? What their real compressed air system efficiency is? 53
Your Real Opportunity Reduce the cost of supplying compressed air by 25% to 50% Stabilize air pressure throughout the plant to within 2 psi. Eliminate compressed air complaints (call backs) Increase plant productivity by reducing rejects, rework, scrap and set-up time Increase compressed air system reliability Decrease or eliminate compressed air caused downtime Optimize installed capital costs 54
What does your Compressed Air Cost??? Why does it Matter? 55
LIFE CYCLE COST COMPARISION PERIOD - 10 YEARS STANDARD COMPRESSORS 10% 2% 11% Initial Purchase Installation Maintenance Operating ( Energy ) 77% Approximately 75% of your compressed air systems life cycle cost is Energy! 56
Quick Quiz Do you know what your compressed air costs? Really? Take a guess and write it down!!!!!
COST OF COMPRESSED AIR: 200 HP $0.10/kWh 100 HP compressor at $0.05/kWh. Costs $140,000/year $35,000/year to run(8,760 hours) This is electrical cost of compressor only! Add in : HVAC, Maintenance, Depreciation, Cooling Water, Air Drying, etc. 4
Quick Estimate of Compressed Air Energy Costs For your facility total all the online, running Compressor HP Determine how many 24 hour days your compressor runs Example if you run 5 days a week two shifts that would equal 5 days x 52 weeks x 2/3 (two shifts) = 173 Days A very quick Rule of Thumb for energy cost near $0.05/kwh $1 / HP / day So if this facility had 200 HP online 200 HP x 173 days x $1 = $34,600 59
Quick Calculation of Your Compressed Air Energy Costs Use the Previous Rule of Thumb and Calculate your Cost $1 / HP / day Annualize your days of compressor run time Note many plants may not run 24/7 production, however it is very common that they do not or can not turn off compressors on the off shifts so effectively many compressors run 24/7 How Close was your Guess? 60
Quick Estimate of Compressed Air Energy Costs The previous example is a very rough method for estimating your costs. It ignores several factors which could add significantly to your actual costs It does not account for maintenance, water, HVAC, dryers or other additional costs The real key is Know Your Cost of Compressed Air! 61
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Simple - Low Cost Steps to Improve Your Compressed Air System Work with a local Compressed Air Partner and establish a compressed air improvement program Compressed Air Audit Establish Long Term Goals Reduce Leaks Leak Audit Ongoing Leak Management Program Reduce your Demand Confirm good End Use Practices Lower your Pressure (try this- lower you plant pressure by 5 psig and see who complains) Establish Minimum Pressure Stabilize your Plant Pressure Improve Efficiency and Reliability by investing the time to understand your Compressed Air System requirements
An Air Audit is Information! What is an Air Audit? It is that simple! Sullair Corporation Confidential 64
An Air Audit is Information! It is that simple! 65
What is an Air Audit? A detailed report that provides the information necessary to make sound decisions on implementing air system improvements based on facts It is a review of the entire system from supply side - to distribution - to point of use (demand side) It uses data logging to document system performance Logs multiple characteristics (pressure, power, dew point, etc.) simultaneously over several days Logging interval must be fast enough to address system dynamics Provides objective analysis with documentation Clearly identifies opportunities for improvements and provides specific unbiased recommendations 66
Four Fundamental Goals of an Air Audit that lead to Tangible Results Goals Establish a Baseline Increase Reliability Improve Air Quality Confirm Good End Use Practices Results Gain Efficiency, Productivity and ROI Can you turn off a compressor??? 67
Establish a Baseline Single Most important step to start improving your system Most Plants do not know Compressed Air costs Compressed Air Usage (CFM) (Peak, Minimum and Average) Compressed Air Quality Requirements Contaminant Level Required Pressure Moisture Content Key Air Users Installed Equipment Inventory Key operational parameters 68
Why have a Compressed Air Audit performed at your plant? Information allows for better decisions! Solve compressed air problems Help size an expansion, compressor, etc. Increase energy efficiency Solve plant floor production problems Improve productivity/reduce waste Efficiency, Productivity, Cost Savings 69
What is your opportunity? Sullair Corporation Michigan City, IN Plant 1 - Existing Electrical Cost $37,875 Savings of $24,000 or 61% Upgrade and payback of less than 1.5 years Plant 2 - Existing Electrical Cost $21,750 Savings of $11,000 or 50% Upgrade and payback of less than 2.0 years Overall Annual Savings $35,000 or 59%
Leaks Can use up to 50% or more of the systems capacity An average plant wastes 20% to 30% of the air produced in leaks Where do the leaks tend to be? Assessing Leak rate Ear Test General Condition Empirical leak test - non production run test Leaks are expensive! 71
How Do You Find Leaks? A $100/year leak can not be felt or heard A $500/year leak can be felt but cannot be heard An $800/year leak can be felt and heard 65 With $0.06/kWh electricity
Common Leak Locations Pipe joints Couplings, hoses fittings FRL s 64 Drains
Leak Flow Rates and Cost Upstream Leak Diameter (Inches) Pressure 1/8 1/4 3/8 1/2 (PSIG) Leak Rate (CFM of Free Air) 80 15.4 61.7 139 247 90 17.1 68.2 154 273 100 18.7 75 168 299 ANNUAL COST OF AIR LEAKS Cost of Energy = 0.10 $ per kwh Upstream Compressor Efficiency = 4 CFM per BHP Leak Diameter (Inches) Pressure 1/8 1/4 3/8 1/2 (PSIG) Leak Rate (CFM of Free Air) 80 $ 2,558.23 $ 10,232.93 $ 23,024.09 $ 40,931.71 90 $ 2,828.37 $ 11,313.49 $ 25,455.36 $ 45,253.96 100 $ 3,098.51 $ 12,394.05 $ 27,886.62 $ 49,576.22 At 10 a kwh a 1/4 leak costs $12,400 year at 100 psig - ouch!!!! That is higher than the cost of the compressor required to produce it!!! 74
Confirm Good End Use Practices Some consider compressed air a necessary evil others consider it free. Neither is correct. Compressed air is a tool like any other. It can easily be applied or misapplied - like using a hammer to drive nails or screws - it can do both jobs - one efficiently with good results one poorly with mixed results. Good uses of compressed air abound - cylinders for lifting, pneumatic controls, nozzles for cleaning or chip removal, hand tools, hazardous areas, etc. Poor practices also dominate - employee cooling, air sweeping, over application of air motors and pumps, etc. While compressed air is not always necessary and is never free it can be just the right tool for the job. 75
Compressed Air Versus Other Energy Sources The overall efficiency of a typical compressed air system can be as low as 5-10 percent Approximate annual energy costs for a 1 hp air motor versus a 1 hp electric motor, 7 day per week, 3 shift operation, $0.06/kWh $ 500 (electric) $ 3,000 (compressed air) $3,500 $3,000 $2,500 $2,000 $1,500 $1,000 $500 Annual Cost of a 1 HP Motor $- Compressed Air Electric 17
Common Point of Use Review Air Motors, Air Operated Pumps, Venturi Vacuum Pumps, etc. To create one horsepower of work with an air motor, pump, etc. it typically takes 5-10 compressor horsepower or more Evaluate your uses - list them and determine if an electric motor can do the job - with equal performance Converting to electric motors saves 80% 77
Potentially Inappropriate Uses Open Blowing Open Blowoffs Personnel Cooling General Cleanup - Air Sweeping Machining - Chip Removal Cleaning - Lubricant Removal Investigate Engineered Nozzles Use Coanda or Venturi effect to use a little compressed air and entrain ambient air to get the same resultant forces Typically use 1/2 to 1/8 the amount of air as opposed to open blowoffs Often concentrate the force to make it more effective Available as Nozzles, Air Knives, Tubes, Amplifiers and custom configurations Savings are typically in the 50-80% Range 78
Engineered Nozzle Savings Upstream Open Tubing Blow Off Typical Engineered Nozzle Pressure 1/8 1/4 3/8 1/8 1/4 3/8 (PSIG) Flow Rate (CFM of Free Air) Leak Rate (CFM of Free Air) 80 15.4 61.7 139 10.0 17.0 18 90 17.1 68.2 154 11.1 18.8 19.9 100 18.7 75 168 12.1 20.6 21.8 ANNUAL COST OF OPEN BLOW OFFS Cost of Energy = 0.05 $ per kwh Upstream Open Tubing Blow Off Typical Engineered Nozzle Pressure 1/8 1/4 3/8 1/8 1/4 3/8 (PSIG) Cost of Air Consumed Cost of Air Consumed 80 $ 1,279 $ 5,116 $ 11,512 $ 829 $ 1,409 $ 1,492 90 $ 1,414 $ 5,657 $ 12,728 $ 917 $ 1,558 $ 1,650 100 $ 1,549 $ 6,197 $ 13,943 $ 1,004 $ 1,707 $ 1,808 That s per Nozzle! With a nozzle cost of less than $50!!!!! Savings range from $450 to $12,135 Annually! 79
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What about Pressure? Do you know what pressure your plant needs to operate? Do you know what pressure is delivered to your plant floor on average? Do you know your critical users and critical pressures? Do you know the squeaky wheels? Do you know why pressure is important? 81
Aluminum Casting Plant 100.0 1 k052997.log: Plant Supply Pressure (Main storage) 80.0 60.0 psig 40.0 Min Max Avg 54.89 psig 97.93 psig 81.61 psig 20.0 0 5/18/97 5/19/97 5/20/97 5/21/97 5/22/97 5/23/97 5/24/97 5/25/97 5/26/97 5/27/97 5/28/97
Pressure is the Key Measurable If you have enough pressure you have enough flow If you have more pressure than you need you are creating more air than you need - over pressure is expensive Savings Key 1 - Cost of Compression For every 2 psig you are able to reduce the compressor set points you save 1% of the total energy cost It costs 5% more energy to compress air to 110 psig than to compress it to 100 psig Savings Key 2 - Artificial Demand An air user that receives air at 100 psig will use 8% less air than a user that receives compressed air at 110 psig 83
Two ways to reduce air usage Reducing orifice size (i.e. leaks, etc.) reduces flow rate Reducing pressure reduces flow rate (Artificial Demand) 100 PSIG 80 PSIG 100 SCFM 5/16 orifice 100 PSIG 80 SCFM 5/16 orifice 80 PSIG 80 SCFM 9/32 orifice 66 SCFM 9/32 orifice Artificial demand causes leaks and productive air users to wastes energy!
But Lowering Pressure is not that easy! Look for pressure drops a 10 psid drop or more across the CRS (dryers and filters) is common - change filters Look for piping issues - a poorly piped feed to one machine may cause 5 psi of drop Look for feeders using hose Hose lengths should be no more than necessary to allow movement for the task at hand. Hoses should never be used as feeders for permanent installations - except for vibration isolation Look for abandoned equipment in line flow meters. inline filters, old dryers, etc. 85
Pressure Drop? 77
Pressure Drop? 77
Where do I start? What do I do? 1) Start simple! Take an inventory of your equipment 2) Baseline your system! Understand your production requirements and how compressed air affects them Have someone in your organization become a Compressed Air Champion 3) Find a compressed air solutions provider! Work as a team to improve the system Find a partner you understand and trust! 88
Understand Your Supply Side! First Inventory Equipment Compressor Type(s) Manufacturer(s) Model(s) Compressor Ratings HP (Driver) Flow Pressure Other Equipment Dryer(s) Filters(s) Storage Tanks Flow Controllers/Sequencers Understand the Room Multiple rooms? Trace the Piping Follow the flow Does it Make Sense? Can you follow it easily Proper Sizing How does it Control? Does the operator understand What is normal conditions? What are set points? Does it sound right? Observe Pressures Set Points Pressure drops 89
Understand your Demand Side Review the plant floor application of compressed air Understand why and where the compressed air is being used Focus on large users Look and Listen for problems and key users Work with the plant floor personnel to identify production issues Production bottlenecks Compressed Air Downtime and Quality issues Safety Issues Work with the plant to create an end use list of all key air users List them by critical or non- critical application Have them provide pressure, volume and air quality requirements List compressed air connection size and location 90
Capturing Real Savings Document your system! Think Long range - a little capital investment can save big Select a vendor/partner for compressed air to help identify bigger opportunities Budget for more extensive studies/ air audits and larger saving opportunities. Remember the Bottom Line - Energy Savings are not all you gain - Productivity! 91
Transition to Predictive Maintenance Use newer technologies to monitor your system Increase Reliability Predictive vs. Preventatives Electronic Control Systems with Maintenance and troubleshooting reminders Real Time Remote Monitoring Maintenance parameters Fault Warnings Direct Callouts Trending and Reporting Datalogging, Thermal Scanning, Vibration Analysis, etc. Sullair Corporation Confidential 257
End of Presentation Questions and Answers