Solutions That Save - CMA/Flodyne/Hydradyne · Financial Ramifications Two separate negative...
58
ENERGY CONSERVATION IN PNEUMATIC SYSTEMS Solutions That Save
Transcript of Solutions That Save - CMA/Flodyne/Hydradyne · Financial Ramifications Two separate negative...
ENERGY CONSERVATION IN PNEUMATIC SYSTEMS
Solutions That Save
Do we recognize the cost of air?
Typical Plant Power Consumption (kW)
Should you focus on compressed air savings?
Idle Mode
Discussion Topics
1. Plant Case Study – The Ripple Effect
Every change, good or bad, results in other changes
2. General Overview of Energy Conservation
1. Air Quality
2. Air Leaks
3. Non-Productive Use of Air
4. Idle Mode Demand
5. Over-Pressurization
Plant Case Study Here’s what can happen when complacency sets in
Plant Case Study At Start Up
65 psi
30 CFM
65 psi
30 CFM
65 psi
30 CFM
65 psi
30 CFM
Total Demand 600 CFM @ 65 psi
2 Compressors running 100 HP @ 90 psi
Plant Case Study Six Years Later
90 psi
80 CFM
100 psi
90 CFM
105 psi
100 CFM
109 psi
105 CFM
Total Demand 1,875 CFM @ 105 psi
9 Compressors running 100 HP @ 115 psi
What happened?
The artificial over pressurization of CP #1 and CP #2 have lead to excessive flow which starves CP3 thru CP20.
Other operators responded to the pressure loss by elevating their own pressure, which results in excessive flow on each machine.
This leads to a plant wide pressure elevation which in turn elevates the flow on every unregulated user including leaks.
The total plant demand excluding the case packers was a mere 200 CFM when the CP’s were installed.
The current plant demand is over 1,350 CFM, excluding the case packers.
Financial Ramifications
Two separate negative financial impacts.
Case Packers costs – those associated with leaks, intermittent demand and point-of-use over pressurization. Annual total $173,585.
Plant wide costs – the cost of elevating plant wide pressure to meet the point-of-use elevation and the cost of inefficient compressor controls at partial load. Annual total $90,452.
Total annual cost to the plant $264,037.
Financial Ramifications
How did we get these dollar amounts?
EfficiencyMotor
kWhperCostOperationofHours.BHPCostAnnual
7460
Calculations will typically use these values: • 8,760 hours of operation
•(24 hours/day X 365 days/year = theoretical maximum)
• 90% electrical motor efficiency (0.90)
• 4 CFM per BHP (Brake Horsepower)
• $0.10 per Kw hour (varies per location, see page 6).
The power-cost formula is:
For example: The annual cost of running a 200 HP compressor:
33.221,145$90.0
10.0$87607460200
.CostAnnual
Financial Ramifications
How did we get these dollar amounts? Let’s look at this another way. . .
What is the annual cost of an air leak?
We have a leak in our system and we’re losing 5 CFM. • Convert CFM to BHP 5 CFM / 4 CFM per BHP = 1.25 BHP
• Apply the formula 1.25 x 0.746 x 8,760 x 0.10 / 0.90 = $908/year
For another example. . .
What is our air blow application costing us? • We use 9 CFM in the application. 9 CFM / 4 CFM per BHP = 2.25 BHP
• The annual cost 2.25 x 0.746 x 8,760 x 0.10 / 0.90 = $1,634/year
What was the catalyst for all this? Poor Air Quality due to lack of proper filtration
Food grade oil was used in compressors:
Oil easily migrated downstream (incorrect mainline filtration) Oil reacts poorly to heat - both in total life and in varnishing
Direct-operated valves stick due to limited shifting force Internally piloted valves required higher pilot pressures
Heat build up in valves contributed to failure (leaking & sticking).
Poor filtration/valve selection for the environmental conditions.
Plant addressed the symptom, not the problem.
Additional Ramifications
Lost production due to pressure swings
Additional breakdown calls related to compressed air issues
Elevated ongoing compressor maintenance costs
Water and oil carryover issues
High scrap rate relative to other plants
Increased capital budget - Significant infrastructure upgrade required
Cost of compressed air was 6.2 times original value
How did we fix this?
Address filtration issues in compressor room to minimize carryover of compressor oils
Added backup filtration at point-of-use Used metal bowls which will not deteriorate from compressor oil Added service indicators Added tamper resistant regulators so that pressure would not be elevated
Replaced direct-acting valves with indirect-acting valves Indirect-acting valves are less prone to sticking & generate less heat Fringe benefit:
Indirect-acting valves lower power consumption from 9 watts to 1 watt
Controlled pressure at point-of-use so that pressure could be restored to 90 PSI
Took un-needed compressors offline, and rotated them into service periodically
Where do we go from here?
Energy Conservation Overview
Energy efficiency is often overlooked on pneumatic systems.
The point-of-use pneumatic products that are applied have a far reaching effect on energy efficiency.
OEM pneumatic product selection is often based on price.
Very little consideration is given to energy consumption, compressed air quality, environmental conditions or sustainability.
When evaluating your compressed air system for energy inefficiency, the first and least expensive place to start is with your pneumatic point-of-use systems.
Energy Conservation Overview
Areas of Energy Conservation
Areas of Focus 1. Air Quality
2. Air Leaks
3. Non-Productive Use of Air
4. Idle Mode Demand
5. Over-Pressurization
Air Quality
Air Quality Sustainability Considerations
Dew point and Particulate Contamination levels are managed by:
Mainline Filter
Point of Use Filter
Dryer
Leaks
Leaks
95% of leaks occur at a pneumatic product other than the mainline plumbing.
The most commonly failed components are:
Fittings and tubing
Air prep units i.e. filter, regulator, lubricator (FRL)
Cylinders or actuators
Why are they leaking? Fittings and Tubing
1. Faulty installation – Accounting for 70% of failures tested during our audits.
2. Poor quality – Tubing or fitting failure not caused by installation or the environment.
3. Misapplication – Fittings or tubing exposed to wash down or other environments they were not manufactured to handle.
Fittings and Tubing
Air Prep Units (FRL’s)
1. Age and general wear – Most leaking components showed failures indicative of general wear which accounted for approximately 45% of failures.
2. Internal exposure to water, Polyolester and Diester oils or rust – These leaks tend to be the largest, accounting for approximately 45% of failures.
3. External damage, operator or mechanical force – Accounting for 10% of failures.
Why are they leaking? Air Prep Units
Cylinders
1. Internal exposure to water, Polyolester and Diester oils or rust – Accounting for approximately 55% of failures.
2. Age and general wear – Most leaking components showed failures indicative of general wear which accounted for approximately 25% of failures.
3. Misapplication – Accounting for approximately 20% of failures.
Why are they leaking? Cylinders
Leaks Case Study
Leaks by Percent of CFM
29%
20%
13%
13%
8%
6%
5%
6%
Fitting FRL Valve Blowgun
Cylinder Coupling Hose Other
Leaks Detection
What a lot of work!
Flow Meters
Parabolic Dish and Ultrasonic Leak Detector
Flow Meters tell us that leaks have developed. Now we need to know
where they are!
Compressed Air Audit Tool of Choice – Ultrasonic Leak Detector Expensive Pack In, Pack Out…Hassle
Auditing Expensive, but…
• Leak repair savings usually recover cost Time-consuming
• Auditor examines plant-wide system Conducted once or twice yearly
• Customer pays every time • Report can be overwhelming
Leaks Conventional Detection
Leaks Automatic Leak Detection System
Goals
Decrease detection cost • Fewer man hours • Lower skill requirement • Lower cost equipment
Increased detection frequency • Minimizes leak impact
Rapidly pinpoint leaks Accurate leakage value
(as low as .07 SCFM)
Leaks ALDS Concept - Implementation
Hardware Flow Meter and Diverter
Valve Installed in machine’s
main air supply line Software Written in the machine’s
PLC Runs leak detection sub-
routine
Leaks ALDS Advantages
Non-Productive Use of Air
Non-Productive Use of Air Air Blow Common Applications
Drying Contaminate removal
Part transfer Open blow
Air-blow has the potential to
be the most wasteful end-
use-application of compressed
air.
Non-Productive Use of Air Air Blow Improvement
Reduce pressure loss and air consumption while maintaining work surface impact.
100 PSI With Nozzle
Without Nozzle 100 PSI 60 PSI
100 PSI
20 PSI
High-efficiency nozzle
Pressure Loss is minimal
Pressure loss is great
Non-Productive Use of Air Air Blow Solutions
Nozzle Diameter
mm
Pressure before nozzle
PSIG Distance
Impact Pressure
PSIG
Air Flow Rate
SCFM Current 4 3 4" 0.25 4 Improved 2 13 4" 0.25 2 Improved 1 30 4" 0.25 1
Non-Productive Use of Air Air Blow High Pressure Solutions
A great amount of money can be saved on blow-off applications by using high efficiency nozzles, regulation and effective tube to nozzle ratios, while maintaining the same impact work pressures required for the job.
High-Efficiency Blow Gun
The ratio of effective area and pressure
Non-Productive Use of Air Air-Blow Solutions
Momentary positive pressure
Appropriate tubing size
Auto shut off when not in use
Venturi style nozzles Reduce to the lowest effective
pressure
Non-Productive Use of Air Design Alternatives
• Primary Considerations – Cylinder Sizing – Double Acting vs. Single Acting – Regenerative Circuits – Tubing length: Filling tube with no benefit – Pressure Control
Pneumatic Model Selection Program Ver4.0-System Model Selection-Standard cylinder Title : Registrant : Date : 2013-07-11Results of model selection
System characteristics
Part numberModel Fitting 1Cylinder
Solenoid valveManifoldSilencer
Speed controller R
Piping R
Shock absorber
NCGT[]A32-400[]SY3240[]-[][][][]-01N
TU0604[]-[]
KQ2L06-U01
KQ2L06-U01KQ2L06-U01
AN103-N01
AS2200-N01-[]AS2200-N01-[]
Stroke:
Total length (R):
Supply pressure:
Full stroke time:
Ambient temperature:
Moving direction:
Total length (L): Speed controller position (R):
Speed controller position (L):
Load mass:
Friction factor:
Application/Load rate: Mounting angle:
Resistance force:
Input values400 mm1.00 sPush (L)0.5 MPa20 degC9.0 ft9.0 ftOn cylinder0 m
On cylinder0 m
55.0 lb N0 degTransfer
Sliding friction
Full stroke time: Start up time:
90% Force time: Mean velocity: Max. velocity:
Stroke end velocity: Max. acceleration:
Max. pressure: Air consumption/ cycle:
Required air flow:
0.81 s0.06 s1.02 s496 mm/s782 mm/s782 mm/s3.8 m/s20.50 MPa3.933 dm3(ANR)156.3 dm3/min(ANR)
TU0604[]-[]
11
11
2
1
2
11
Absorption energy: Allowable energy: 0.91 J
7.77 J
Out of the allowable rangeJudgment result: Out of the allowable range: Review the operating conditions and the load conditions. Or use shock absorber.
Condensation probability is very small
0 %Condensation probability: Cushion Calculation Input Value
Condensation Calculation Input Value
Cushion style: Air cushionWork mounting style:
Cushion Calculation Result
0.0008 kg/ kgAbsolute humidity:
Condensation Calculation Result
Comment:
0.7
0.3
Quan. Quan. Quan.Fitting 2
Opening: 100 %
Opening: 100 %
Silencer opening: Quick exh. valve opening:
Selection method: Optimal size priority
Speed controller L
Piping L
Quick exhaust valve
SMC Version: 4.0.01
Non-Productive Use of Air Design Alternatives - Cylinders
Pneumatic Model Selection Program Ver4.0-System Model Selection-Standard cylinder Title : Registrant : Date : 2013-07-11Results of model selection
System characteristics
Part numberModel Fitting 1Cylinder
Solenoid valveManifoldSilencer
Speed controller R
Piping R
Shock absorber
NCGB[]A50-400[]SY7240[]-[][][][]-02N
TU0604[]-[]
KQ2L06-U02
KQ2L06-U02KQ2L06-U02
AN202-N02
AS2200-N02-[]AS2200-N02-[]
Stroke:
Total length (R):
Supply pressure:
Full stroke time:
Ambient temperature:
Moving direction:
Total length (L): Speed controller position (R):
Speed controller position (L):
Load mass:
Friction factor:
Application/Load rate: Mounting angle:
Resistance force:
Input values400 mm1.00 sPush (L)0.5 MPa20 degC9.0 ft9.0 ftOn cylinder0 m
On cylinder0 m
55.0 lb N0 degTransfer
Sliding friction
Full stroke time: Start up time:
90% Force time: Mean velocity: Max. velocity:
Stroke end velocity: Max. acceleration:
Max. pressure: Air consumption/ cycle:
Required air flow:
1.00 s0.07 s1.36 s401 mm/s538 mm/s538 mm/s10.1 m/s20.50 MPa9.015 dm3(ANR)293.5 dm3/min(ANR)
TU0604[]-[]
11
11
2
1
2
11
Absorption energy: Allowable energy: 3.40 J
3.82 J
Out of the allowable rangeJudgment result: Out of the allowable range: Review the operating conditions and the load conditions. Or use shock absorber.
Condensation probability is very small
0 %Condensation probability: Cushion Calculation Input Value
Condensation Calculation Input Value
Cushion style: Air cushionWork mounting style:
Cushion Calculation Result
0.0008 kg/ kgAbsolute humidity:
Condensation Calculation Result
Comment:
0.7
0.3
Quan. Quan. Quan.Fitting 2
Opening: 100 %
Opening: 100 %
Silencer opening: Quick exh. valve opening:
Selection method: Optimal size priority
Speed controller L
Piping L
Quick exhaust valve
SMC Version: 4.0.01
55 lbs. / Sliding 16” / 1 second
2” bore ~10 SCFM
1-1/4”” bore ~5 SCFM
Non-Productive Use of Air Design Alternatives - Cylinders
Consider Single-Acting over Double Acting
•Ways to save: • Gravity Down?
• Single Acting Cylinder?
• Regenerative Circuits
40% Savings
Non-Productive Use of Air Design Alternatives - Tubing
Tubing Length • Consider that air used to fill the tubing on the way
to the actuator does no work!
• The conductance of tubing decreases dramatically with an increase in length – Shorten tubing as much as feasible – Beware that larger diameter = larger volume – Size tubing for flow required – don’t guess!
Non-Productive Use of Air Design Alternatives - Tubing
Right Sizing Tubing Diameter – Example 4 cylinder case erector
3/8" Tubing 1/4" Tubing
Operating Pressure 50 50
Bore (inch) 3 3
Stroke (inch) 3.41 3.41
# of cylinders 4 4
Tubing Length (inch) 96 96
Tubing I.D. (inch) 0.25 0.16
# of elbow fittings 2 2
Rate: Cycle Time (sec) 1.5 1.5
CFM Required 25 21
Annual Cost of Operation $ 4,979 $ 4,120
ANNUAL SAVINGS $ 625
The savings is a reduction of
4.14CFM or 17.3%.
Of course, if you had used a cylinder with integrated valve, the savings would have
been $855
Non-Productive Use of Air Design Alternatives - Pressure
Extend and retract strokes frequently do not require the same operating pressure. A reduction in pressure on the non-working side of the cylinder will lead to significant energy savings.
Idle-Mode Savings
Idle Mode Demand
• Examples –Machines need to shut off when not in use – Isolate during breaks, maintenance, etc. –Machines typically do not operate 100%
Idle Mode Demand
Idle Mode Demand Macro Example – When reviewing a plant-
wide flow study, Idle Mode demand may be defined as: Compressor operation to meet a zero production demand.
Idle Mode Demand Micro Example – On a single piece of OEM equipment, Idle Mode demand is defined as: Equipment leaking while an operator stops production
equipment from running during a product change over, preventative maintenance or scheduled operator breaks.
Whether it is a macro or micro problem, Idle Mode demand during
idling can be a significant draw on a compressed air system.
Intermittent Demand Macro Case Study
Idle flow 5,420 CFM Annual cost $145,541
Paint
6/27/06 12:00 - 7:00 AM
2000
3000
4000
5000
6000
7000
8000
9000
10000
0:00 1:00 2:00 3:00 4:00 5:00 6:00 7:00
90
91
92
93
94
95
96
97
98
99
100
CFM
PSI
Waste
1 2 3 4 5 6 7 8
Leaks 22.60 CFM
Air supply + leak ... 60 CFM Current situation at snack chip manufacturer
Intermittent Demand Micro Case Study
1 2 3 4 5 6 7 8
Leaks 22.60 CFM
Air supply + leak 60 CFM
Shut Off Valve D
E Shut Off
Valve
Auto Drains
Auto Drains
Proposed solution to intermittent demand
Intermittent Demand Micro Case Study
Intermittent Demand The Cost of the Case Study
The current leak load is 22.60 CFM.
Cost is $4,102 for leaks per packaging line $4102 * 8 lines = $32,816 per year Savings = $10,830 per year.
Intermittent Demand Solutions
When you require a moment of positive pressure
When product is present
Auto shut off used in conjunction with equipment power or photo eye.
Soft-Start / Quick Exhaust Valves
Over -Pressurization
Over-Pressurization
Excessive pressure in a manufacturing plant often starts at the point-of-use.
Plants often respond to decreasing performance at a machine by
increasing regulator set pressures and often the entire plant’s pressure.
It’s imperative to evaluate the cost of over-pressurization\ Generally, a 2 PSI increase adds about 1% more to energy costs
Over-Pressurization Examples
Equipment operators rarely understand the relationship between flow and pressure. What leads to excessive pressurization of pneumatic systems? Misdiagnosis of equipment malfunction Flow rate increases force a “droop” in downstream pressure Mismanaged point-of-use filtration In each case, equipment operators respond by increasing the pressure at the regulator.
Excessive Pressure Case Study
Over Pressurization
100 psi vs. 80 psi
40
50
60
70
80
90
100
110
120
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00
Time (Minutes)
psi
40
50
60
70
80
90
100
110
120
CF
M
Pressure (psi)
Flow (CFM)
Pressure (psi) 100 80
Flow (CFM) 71.40 57.10
Annual Cost $13,069 $10,047
Statistics
Excessive Pressure Solutions
Use gauges with visual pressure range display
Excessive Pressure Solutions Continued
Precision Style Regulator
Locking Regulator
Regulators with locking adjustment knob or a pressure lock out device prevent costly over-pressurization
Manage pressure with precision regulators Tamper Resistant Regulators
Tamper Proof Regulators Restricted Regulators
E/P Control
Wrap up!
Savings start in the design phase at the OEM level, however…
For existing systems:
Evaluate your compressed air system from point-of-use backward.
Reduce consumption Avoid the temptation to buy more compressors before you know for sure that
this is the right energy solution
Enjoy the quick return on investment!
If you have any questions or require additional information, please do not hesitate to
contact SMC!
Thank you!
