all energy exhibition & conference, glasgow, may 2017

ALL-Energy Exhibition & Conference,

Glasgow 2017

Compressed Air Systems – Are

You Blowing Your Profits ?

Hugo Gallagher

C.Eng, MIET, MSc, B.Eng (Hons), B.Eng, HND

Managing Director of Logis-Tech Associates (sub division A-1 Technical Training)

ALL-Energy Exhibition & Conference,

Glasgow 2017

Compressed Air Systems – Are You Blowing Your Profits ?

Compressed Air Systems

Whole System Approach to saving energy

Pipework, valves, design

Calculating air system’s annual costs

Finding leaks using ultrasonic detection methods

Fixing leaks

Good Housekeeping and staff involvement

Overview of how to save energy in a typical

compressed air system

Compressed air often referred to as the fourth utility.

Essential to many sectors as a safe, reliable and versatile source

of power.

Take a considerable amount of energy, generally in the form of

electricity, to produce clean, dry, pressurised air that is needed

for so many processes and applications.

Compressed Air

Typically, is 10% to 30% of an industrial company’s electricity bill

Some sectors it can equate to far more.

Makes sense to take targeted action and make your system more

efficient.

Reducing compressed air waste will:

• Save energy and costs

• Improve reliability and productivity

A Typical Compressed Air System

Compressed Air System

Every element of a compressed air

system impacts upon its energy

consumption.

A mistake to just concentrate on

one aspect of the system

To the exclusion of other sections.

Result in missed opportunities to

saving energy.

Efficient Compressor

Eg,Purchase the most efficient compressor on the market but connected it

to a system that has a 40% leak rate

All you are achieving is to produce waste more efficiently!

While the largest energy consuming component in the system is the air

compressor(s)

It is the demand by users, overall design and how well the system is

maintained that determines the demand placed on the compressor to

supply the system and therefore its energy consumption.

Compressed Air Pipework

Not all parts of the network operate the same hours

or to the same pressure, so save energy by zoning

the compressed air system.

• Split the system into zones and pressurise each

only as required

• Remove/isolate redundant piping so that it does

not leak out of hrs

Compressed Air - Valves

Widely used for isolating parts of the distribution network.

Best option - Ball valves cause almost zero pressure drop

when fully open

Not so good - Gate valve design causes pressure drop and

leaks when left partially open for convenience

Avoid - Diaphragm and globe valves cause the largest

pressure drop

Compressed Air – Good Design

All compressed air distribution pipelines to min. pressure

drop and allow for possible future expansion of the

compressed air system:

• Select large radius bends instead of elbows

• Support piping to minimise movement and sagging to

reduce leaks and build-up of fluids

Compressed Air Pipe size and energy losses

Installing a smaller pipe to save on the initial capital cost is a

false economy.

Smaller piping causes greater pressure drop across the

system, resulting in higher energy consumption and this

increased energy cost soon exceeds the price of larger

diameter piping.

General Rule – Pipe Diameters

Calculated based on having a max. air velocity of 6m/s,

in the main supply line.

In branch lines with a total length less than 15m,

velocities up to 15m/s are acceptable.

Pipe Systems

Two basic distribution systems for compressed air are single main and ring main.

For larger systems with numerous take-off points then a ring main is recommended.

Isolation valves can be fitted to isolate specific sections of the system for maintenance

purposes.

When selecting pipe material consider the alternatives to traditional galvanised steel, which

eventually corrodes and has a much rougher internal surface.

Smooth bore aluminium pipe (both tube and box types), stainless steel and specialised

plastics offer much lower friction and flow resistance to the air. This reduces pressure

drop and saves energy, plus these materials do not corrode

and potentially contaminate the air.

Calculating the system’s annual costs – Option 1

The actual electrical consumption of the compressor(s) in

kilowatt hours (kWh) can be obtained by sub-metering the

compressor house.


A quicker temporary solution is to install a data logging system over a period

of at least seven days.

This will determine:

• Pattern of demand (demand profile)

• Off load running time when there is no demand for air

In addition to add further information to help build a usage picture, you could

also incorporate flow monitoring into the system.


If no metering is in place, then you can estimate the energy

consumption of each compressor

Eg, A 75kW compressor operates at 7 bar.

It is on load for 65% of the production time (2,000 hrs/year).

Motor is assumed to be 90% efficient.


Energy consumption of the compressor whilst on load =

(75 ÷ 0.9) x 0.65 x 2,000 = 108,333 kWh/year

There is also energy consumption from the offload running, assuming for a screw compressor that a

part-loaded running draws 25% of the full load power:

(75 ÷ 0.9) x 0.35 x 0.25 x 2,000 = 14,583 kWh / year

Total energy consumption of the compressor = 122,916 kWh

Electricity Cost

For unit electricity of £0.12/kWh, the annual energy cost is £14,750.

If production time is 6,000 hours per year, this increases to £44,250/year.

For older or less efficient compressors where the offload electrical draw can be nearer

70% of on load power (not 25% as in the example), then the annual energy cost for

2,000 hr operation increases from £14,750 to £17,900 per year.

Another method for estimating energy consumption of compressors is to use the max.

rated package power, a figure available from the manufacturer.

Calculating System’s Annual Costs - Summary

The cost of the compressor, not the system.

However, it is a starting point and helps you understand the scale of expenditure

Examine the entire compressed air system to maximise energy savings

Compressed Air Leaks

All compressed air systems have leaks.

Leaks are often ignored since they are not an immediate H&S hazard

Reducing air leaks is the single most important energy saving measure you can take.

A high leak rate causes fluctuations in pressure, resulting in hidden costs such as

slower running or the stalling of production lines

creates a noisy environment for staff.

Common leakage sources are

Air-using equipment left running when not needed

Manual condensate drain valves left open

Leaking hoses and couplings

Leaking pipes and pipe joints

Estimate your leak rate as a percentage of

total demand,

Carry out the load /no load cycle test

This is easily done with a stopwatch to find the percentage of time the

compressor is on-load when there is no demand for air.

Estimating a Compressed Air System’s Leak

Rate Using the Load /No Load Cycle Test.

1. Use a timer e.g. stopwatch to measure the time (T) that the compressor is actually

delivering air (on-load).

2. Repeat this for the duration of time (t) that the compressor is off-load.

3. Repeat these measurements through at least four cycles to obtain accurate average

values.

Note: If the air compressor actually switches off and on, then this is

straightforward.

If the machine keeps running but uses an off-loading mechanism, then listento the

tone of the compressor as it cycles between the two states.

Estimating a Compressed Air System’s Leak

Rate Using the Load /No Load Cycle Test.

4. Note the delivery capacity of the air compressor (Q) from the nameplate or literature.

5. Use the following formula to determine the leak rate, Qleak which will have the same

units as Q (e.g. litres/s or m3/min):

Qleak = Q x T/(T+t)

Identifying and Measuring leaks

Initially conduct an out of hours survey and walk the site

listening for leaks.

Confirm the location by using any of the following

methods: ultrasonic leak detector, a soap solution

brushed onto pipe fittings, or a leak detection spray.

Handheld ultrasonic leak detectors are the best way to

detect leaks whilst production is running.

EP500Air leak Ultrasonic “Easy Flex” Detector

Finds the leak fast, easy and efficient reducing energy costs considerably.

EASY” to operate without any training at all – you simply use it.

A leak will produce an audible sound in the headset and even tiny leaks can be detected from 15 - 20 meters away. The device is equipped with a gooseneck allowing access to hard to reach hoses and connections.

Technical SpecificationsLight-weight headset with vol. controlFreq. range: 38 – 42 kHzMax. distance to leak (7 bar, size Ø0.5 mm): 20mBattery: 9V (PP3 / 6LR61), alkalineOperating time: more than 25 hrsOperating temp.: -10°C to +45°CWeight: 270 g

LEAKSHOOTER® LKS1000-V2

TURBULENT FLOW & ULTRASONIC WAVE

ULTRASONIC DETECTION-WHY?

Turbulence in the flow of fluids and gases emit high levels of ultrasonic waves. In an industrial plant, pressurized leaks in pneumatic air lines, steam lines and vacuum lines emit ultrasonic waves.

Internal leaks in valves, steam traps and hydraulic systems also produce ultrasonic waves as well as mechanical wear in bearings and gears.

Ultrasonic waves are very strong at the leak origin and decrease with distance. They are also very directive.

For years, ultrasonic inspection techniques have been used in plant maintenance programs to reduce energy costs and increase equipment reliability.

Pressure

P

Pressure

P ATM

Turbulence

Ultrasonic waves

Leak

LEAKSHOOTER® LKS1000-V2 – What is it ?

SEE & HEAR LEAKS:

LEAKSHOOTER® LKS1000-V2 is a portable leak detection camera, which combine ultrasonic and visual camera technologies around a “real time” calculation software, to give you an easy way to view the leak location on the screen and to hear the leak in the headphone.

LEAKSHOOTER® LKS1000-V2 stores the leak location photo to be downloaded later to a PC for reporting.

LEAKSHOOTER® LKS1000-V2 quickly repays its initial cost outlay and could save your company substantial energy costs and improve overall system efficiency.

LEAKSHOOTER® LKS1000-V2 – How does it work ?

SEE THE INVISIBLE:

Simply scan your installation with the handheld LEAKSHOOTER® LKS1000-V2.

When the cone is aligned with the ultrasonic waves, LEAKSHOOTER® LKS1000-V2 shows you a dynamic target (yellow or red depending on the size of the leak) on the screen. This is the location of the leak.

If the target has a cross inside it, you are in front of the maximum ultrasonic waves, so in front of the leak.

Of course, you can manually adjust sensitivity (Gain) of the integrated ultrasonic sensor to be able to find both big (less sensitive) or small (more sensitive) leaks.

LEAKSHOOTER® LKS1000-V2 – For which applications ?

COMPRESSED AIR :

LEAKSHOOTER® LKS1000-V2 will

help you to find compressed air leak

locations, even in a very noisy

environment.

Find, identify and repair the leaks.

Make Energy Savings, work more

efficiently (ISO 50001).

LEAKSHOOTER® LKS1000-V2 can

help you saving a lot of money.

Do not forget one permanent 1mm

leak@7BAR cost about 250 €/year.


COMPRESSED PROCESS GASES :

LEAKSHOOTER® LKS1000-V2 will help you to find compressed process gases leak locations like O2, CO, CO2, N2, Argon, H2…, even in a very noisy environment.


Work more SAFELY.

LEAKSHOOTER® LKS1000-V2 can help you saving a lot of money.

Do not forget a process gas leak can be very dangerous...


VACUUM :


help you finding industrial vacuum leak

locations, even in a very noisy

environment.


Work with a better EFFICIENCY.



Flexible probe is often useful for close

vacuum leak detection.


TRAP/VALVE INSPECTION :


help you inspecting trap or valve, to find

malfunctions, even in a very noisy

environment.

See & Hear what happen inside.

Make Energy Savings, work more

efficiently (ISO 50001).



Contact probe is needed for trap &

valve inspection.


HIGH VOLTAGE INSPECTION :


help you inspecting from the ground high

voltage electrical installation.

See & Hear malfunctions like corona,

partial discharges, tracking, arcing...

Work with a better efficiency and avoid

high cost breakdown.



Detect up to 15m with integrated cone.

LEAKSHOOTER® LKS1000-V2 – STANDARD PACK

1x LEAKSHOOTER® LKS1000-V2 device

1x universal power charger 230V-50Hz/60Hz > 5V/2A

1x USB cable for PC connection

1x stereo headphone with jack cable

1x strong aluminum case

1x user manual

1x manufacturer certificate

Leakshooter Ultrasonic Leak Detector Camera

leakshooter Video with Cone

Leakshooter with Flexible Probe

https://www.youtube.com/watch?v=6_UK7isO3Lw

https://www.youtube.com/watch?v=LypsVCVNc_A

https://www.youtube.com/watch?v=kcaWGCC6FDU

LEAKSHOOTER® LKS1000-V2 – ACCESSORIES

(1)

LEAKSHOOTER® LKSFLEX 1500 mm or 400 mm

LEAKSHOOTER® LKSPROBE LEAKSHOOTER® LKSCOVER LEAKSHOOTER® LKSBATT

LEAKSHOOTER® LKS1000-V2 – ACCESSORIES

(2)

LEAKSHOOTER®

LKSLEAKTAG

LEAKSHOOTER® LKSDOME

(for tightness tests in big

volume, 13 ultrasonic powerful

emitters)

FRONT BACK

Air Leak Survey

Survey Carried Out By …………………….

Report Compiled By ………………………

Date ………………………

Company: XXXXX Ltd

Compressed Air Pipework and fittings Survey

Checked using a Leakshooter

LKS1000 v1 acoustic/ultrasonic leak

detector.

Where a leak was found it was tagged

and numbered using red or white

tags. Leaks were numbered for

identification and given a rating from

1 to 5 based on the severity of the

leak. This is shown in the table

Leak

Rating

Severity

1 Low

Leakage

2 Low/Medium

3 Medium

4 High

5 Major

Leak 1

Packing Plant, Line 3 Mezzanine Floor

Flexi Hose Rating - 3

Leak 2

Packing Plant, Line 3 Mezzanine Floor

Flexi Hose Rating - 2

Leak 3

Packing Machine (Floor 1)

Flexi Hose Rating 4

Leak 4

Packer 1 (Top Floor)

Major Air Leak underneath machine Rating 5

Leak 41

Raw Mill

Fitting Rating 4

Leak 51

Cooling Tower (Floor 1)

Big door air tight seal Rating 5

Leak 54

Dome

Dust Covers Rating 3

How Much Could You Save?

54 leaks in total taking a average leak at 3cfm (cubic

feet/minute). = 162cfm of waste.

162cfm = 26kw Compressor

26kw x £0.12p/kw/hr x 24hrs x 7days x 50 weeks

= £26,208.00 Electrical costs in Leaks, Per Annum

Companies using the leakshooter LKS1000v2

Airbus, GSK, JCB, Ford, Nissan, Aptar, Nampak, Tubelines, Heidleberg,

SG Equipment, Eriks, Brammar, Atlas Copco, Premier Foods, Arla Foods,

Nestle, Tata Steel, MH Pneumatics, Sanofi, United Biscuits, Thorite, Air

Compressor Blowers, Direct Air, Morningfoods, BMW, NHS, Adastra,

Ormandy, Skretting, SmithAnderson, Kingspan, Pablon, Bellfield, Yess

Electrical, Orta, Derek lane Ltd, Agility, BMW, Unicron, Electronic

Systems, Intelligent-Energy, Defy, Perkins Engines, Dickson Bearings,

Airwise, Storm Procurement, PZ Cussons, SSE, Lomax Food processing,

Environmental Options, IRESA, Predictive Condition Monitoring, etc,…

Leak Management Programme

Tag the leaks and record on a site plan

Grade the priorities - it could be as simple as 1,2,3

Fix the largest leaks first

Encourage users to report leaks

Repair all leaks as soon as practicable

Leaks need to be monitored constantly. Carry out a leak survey at least 3 – 4 times a

year to keep the problem under control.

If you have insufficient in-house resources, speak to Logis-Tech Associates

Leaks Repaired – Pressure Drop

Once leaks are repaired, check the pressure drop from the compressor to points

of use as you may be able to reduce the generation pressure at the compressor.

Otherwise fixing leaks could increase the pressure and the predicted savings

will not be realised.

Also the increased pressure could create more new leaks.

In order to monitor the leakage rate, consider installing permanent flow

metering.

This is also an effective way of identifying any changes in consumption which

need further investigation.

Good housekeeping and staff involvement

Many users are unaware that the compressed air generated is not free and therefore ignore leaks and use air indiscriminately.

You should involve your staff in identifying where compressed air is wasted and how they can help by reporting the problem and making suggestions.

The main areas of wasted usage to target are:

Leaks

Leaving air consuming equipment running during breaks

Using compressed air lines for cleaning down benches and equipment

Draw up a Usage Policy

Appoint someone with overall responsibility to ensure

coordination and implement an action plan to:

• Raise awareness of all those who use compressed air

• Establish compressed air costs

• Set targets for reducing avoidable waste

Switch off the Compressor When There

is No Demand

Do not leave compressors on overnight if there is no demand for air because electricity

will be consumed to feed leaks.

Even when off-load, compressors can consume up to 70% of their full load power.

Fewer running hours will also reduce maintenance costs.

• Check that compressors are switched off when not needed and are not switched on earlier

than necessary

• Check time switch settings regularly

Note: Ensure that when automatically shutting down the compressor, that other

plant areas are not affected

Maintain the whole system

Effective maintenance is essential to energy efficiency.

Cutting back on maintenance is a false economy, because doing so increases

the energy consumed, decreases service life and reduces equipment

reliability. In addition, the law requires all systems operating at greater than

0.5 bar with an air receiver installed, to comply with the Pressure Systems

Safety Regulations 2000 (PSSR).

Reg. 12 of the PSSR requires that compressed air equipment be properly

maintained to minimise health and safety risks associated with a pressurised

system

Further Info: Guides, Literature, case studies

www.bcas.org.uk

www.referenceline.com/bcas

https://www.gov.uk/guidance/energy-technology-list

http://e-learning.bcas.org.uk - for online training

http://www.cagi.org

https://www.compressedairchallenge.org

http://www.hse.gov.uk/pubns/indg261.pdf

all energy exhibition & conference, glasgow, may 2017

Engineering