93
Brit Thielemann Product Manager - Stationary Air Products Sullair
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
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
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
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 - valvedand 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 33oF 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
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.
Deliquescent Dryer / Absorbtion type
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.
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
1/100th 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
50
COMPRESSED AIR IS FREE, RIGHT???
Why do we care about the energy costs of compressed air systems?
51
Energy Savings Potential from Compressed Air System Improvements
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%!!!
Conservative Estimate Of Energy Savings
$5.4 Billion annual electrical costs
x $.06 per kWh national average energy rate
$810 M - $3.2 B in potential savings in U.S. markets
$810 M - $3.2 B in potential savings in U.S. markets
90 Billion kWh in U.S. consumed by
compressed air systems annually
x 15% - 60% average savings
$5.4 Billion annual electrical costs
52
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 systems1
16% of all motor system energy consumed in the US is by compressed air systems1
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%
1. Data from the U.S. Department of Energy
More Air is not
the Answer!
53
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?
54
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
55
What does your Compressed Air
Cost???
Why does it Matter?
56
LIFE CYCLE COST COMPARISION
PERIOD - 10 YEARS
STANDARD COMPRESSORS
10%2%
11%
77%
Initial Purchase
Installation
Maintenance
Operating ( Energy )
Approximately 75% of your compressed
air systems life cycle cost is Energy!
Quick Quiz
Do you know what your compressed air costs?
Really?
Take a guess and write it down!!!!!
COST OF
COMPRESSED AIR:100 HP compressor at $0.05/kWh.
Costs $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
$0.10/kWh
$140,000/year
200 HP
59
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
60
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?
61
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!
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
Sullair Corporation Confidential 64
An Air Audit is Information!
It is that simple!
What is an Air Audit?
65
An Air Audit is Information!
It is that simple!
66
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
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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???
68
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
69
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
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%
71
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!
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
With $0.06/kWh electricity65
Common Leak Locations
Couplings, hoses
fittings
Pipe joints
FRL’s
Drains64
74
Leak Flow Rates and CostUpstream 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 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$
Compressor Efficiency = 4 CFM per BHP
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!!!
75
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.
Confirm Good End Use Practices
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)
17
Annual Cost of a 1 HP Motor
$-
$500
$1,000
$1,500
$2,000
$2,500
$3,000
$3,500
Compressed Air Electric
77
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%
78
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
79
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$
Engineered Nozzle Savings
Savings range from $450 to $12,135 Annually!
That’s per Nozzle! With a nozzle
cost of less than $50!!!!!
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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?
Aluminum Casting Plant
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
0
20.0
40.0
60.0
80.0
100.0
psi
g1 k052997.log: Plant Supply Pressure (Main storage)
Min 54.89 psig
Max 97.93 psig
Avg 81.61 psig
83
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
Two ways to reduce air usage
100 PSIG
5/16” orifice
100
SCFM
100 PSIG
9/32” orifice
80
SCFM
80 PSIG
5/16” orifice
80
SCFM
80 PSIG
9/32” orifice
66
SCFM
• Reducing orifice size (i.e. leaks, etc.) reduces flow rate• Reducing pressure reduces flow rate (Artificial Demand)
Artificial demand causes leaks and
productive air users to wastes energy!
85
But Lowering Pressure is not that easy!
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.
Look for pressure drops
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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!
89
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
90
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
91
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!
Transition to Predictive Maintenance
Use “newer” technologies to monitor your system
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
Increase ReliabilityPredictive vs. Preventatives
End of Presentation
Questions and Answers
