Acoustic Imaging Helps You Manufacture More Sustainably: Step One; Compressed Air System Audit

Greenhouse gas emissions are on the increase and so is the percentage of pollution originating from processes used in manufacturing. But environmental organisations, governments, and policy makers have recently imposed regulations on manufacturers in an attempt to limit the harmful pollutants they spew into the atmosphere. Therefore, manufacturers need affordable solutions that effectively eliminate unnecessary waste and allow them to comply with ever changing government rules.

Maintenance and reliability teams often forget the role they play in sustaining the environment simply by performing their everyday tasks. The design, operational objectives, day-to-day activities, and culture of a facility all factor into their emissions.

Placing emphasis on conserving energy output by cutting down on inefficient operating activities and compromised equipment is the easiest way for maintenance and reliability to positively impact plant sustainability.

Whether the inefficiencies are a result of improperly lubricated bearings requiring twice the energy to rotate, failed steam traps contaminating pure steam, or leaky facilities racking up expensive heating and cooling bills, it all adds up to hundreds of thousands in losses, while negatively affecting plant sustainability. That being said, there is one commonly misused and wasted utility above all else. It is so heavily relied on in industry, it is often referred to as the fourth utility… and that is compressed air.

Compressed Air

Upwards of half of the compressed air a facility produces for their manufacturing processes never reaches its intended point of use. Even though it is among the lowest hanging fruit factories can pluck to reduce energy costs and improved plant sustainability, compressed air is often overlooked by maintenance and reliability as viable for repair.

Reasons for this attitude towards leaking compressed air systems may be because they are difficult to detect without the proper equipment, they don’t produce odour, or visible messes on the floor, they don’t pose a threat to plant safety, and they rarely stop production.

The Real Cost of Leaks

One of the highest operating expenses of a factory is the compressed air system, and more specifically, the energy consumed by the compressed air system. Only about 25% of the total cost of a compressed air system is capital cost and maintenance. The remaining 75% of those costs is operational energy expenditure.

Over time if enough leaks are present, an air compressor falls behind on demand. With a compressed air system in a state of disarray, system pressure fluctuations take place, affecting production. This forces the air compressor to work double time, leading to earlier degradation of that asset, more maintenance, and a greater risk of an unplanned breakdown.

When a facilities compressed air demand is unmet the manufacturer often blames the compressor & then makes a choice: buy another compressor for more capacity, or optimise the compressed air system to deal with demand, by finding and fixing wasteful, expensive leaks.

Plucking the Low Hanging Fruit

SDT Ultrasound Solutions recommends at the very least, one annual compressed air system audit using ultrasonic leak detection. It is considered the lowest hanging fruit in terms of manufacturers realising financial and sustainable wins for their facility.

A good quality Acoustic Imaging Camera blends visual and auditory senses to bring compressed air leaks into focus,  ideally detecting the smallest sources of ultrasound in loud manufacturing environments from upwards of 50 metres (150 feet).

A simple leak detection procedure consists of picking up the camera, powering it on and connecting headphones. Then simply by pointing the acoustic sensor array towards any compressed air lines and listening for the characteristic hissing of the compressed air leaks while watching for the display to light up, a technician can find and report leaks easily.

Supplementary Reading

Best Practices for Performing a Compressed Air Leak Survey

Veteran Airborne Ultrasound Inspector, Paul Klimuc outlines his crucial points for performing this essential maintenance task.

1. Safety Considerations
2. Determining Frequency of Inspections
3. Learning the Network
4. Frequently updating Plans
5. Planning the Inspection
6. Choosing Equipment
7. Recording the Data
8. Celebrating Wins!!!

To read this article, click here.

Top 10 Most Common Leak Spots in your Compressed Air System

1. Main Supply Line and Branch Connections
2. Quick Coupler
3. Filters
4. Pneumatic Cylinders
5. Dryer Assembly
6. Pressure Regulators
7. Rubber Pipes
8. Lubricator Assemblies
9. Isolation Valves
10. Automatic Drain Traps

To learn more about detecting compressed air leaks at each of these specific points, click here.

Realising ROI using SonaVu InSights™

SonaVu InSights™ is a web application that creates instant reports of compressed air leak surveys performed with the SonaVu Acoustic Imaging Camera. With InSights, an inspector can document findings, prioritise repairs, estimate cost impact, eliminate energy waste, and save money.

The following is a compressed air leak system audit performed with a SonaVu Acoustic Imaging Camera & documented using SonaVu InSights. The audit only included one small section of a large paper mill, and our technician found around $7,274-$8,891 in annual losses due to compressed air leaks.

Here is an example of a leak captured during the survey which totals annual losses of around $1290-$1576.

Compressing air is an energy inefficient process, but entirely necessary for modern manufacturing. When a compressed air system is leaking, it affects plant reliability, sustainability, and the bottom line. Finding and fixing compressed air leaks is the fastest way manufacturers can obtain a return on investment and logically should be the first step a company makes towards their goal of manufacturing more sustainably.