Compressed air auditing is essential. Monitoring your compressed air quality is important to ensure the health of your clients and your brand. By not knowing the facts about your compressed air consumption and your facilities compressed air, you are potentially wasting millions every year.
As much of 10% of all electricity generated is consumed by air compressors, and some 50% of this energy is wasted. Air leaks alone can account for 25% of these values. Therefore, it is crucial to audit your compressed air (c/air) system.
What are the components of a comprehensive air audit? These are the basic steps in reducing operating costs for your compressed air system:
- Air quality monitoring. Audit the quality of the compressed air, dew point, particle count and oil carry over to quantify your compressed air quality.
- Monitor and determine the compressors kW/m3 efficiency.
- Measure the air flow and pressure entering a system for at least seven days or more to evaluate your usage and reduce compressed air wastage. This benchmarks the production areas and enables you to quantify the cost of c/air/unit of product produced.
- Undertake routine ultrasonic leak detection surveys to minimise compressed air wastage.
- Review, identify and eliminate wasteful air consumption practices/equipment.
The compressed air quality to food and beverage plants is critical as in many cases compliance to an ISO 8573 standard is applied. When compressed air is in direct contact with food and beverages, it is essential to know and validate compressed air quality.
Compressed air contains a wide range of impurities, these include, water vapour sucked into the air compressor from the atmosphere, possible oils from the compressor station, and airborne particles from the compressed air distribution system and/or the air intake of the compressor. These contaminants can be present in an airline. Moisture in the air line creates an environment in which harmful bacteria can breed within the compressed air distribution network and these bacteria may then be transmitted to the point of use.
Compressed air quality monitoring
Compressed air treatment using filters and low dew point dryers is a barrier to airline contamination, but nothing is ever perfect. Until recently the ability to audit the compressed air quality in a system was time consuming and difficult, if not near impossible. Advances in this area have accelerated rapidly in the last few years. Clients and compressed air auditors like Artic Driers, now have the ability to measure contaminants with stunning accuracy in the following areas:
- Compressed air dew point (dryness) from -100 – +20°C Td
- Particle counts within the compressed air stream (dust, pollen, rust) from 0.1 ≤5µm
- Oil vapour carry over in the line after the c/air treatment package from 0.003 – 10 000mg/m3
There are two options for the facilities manager, a fixed monitoring station, that monitors on a permanent basis or a portable auditing option for use by auditors or compliance officers.
Artic Driers International can offer both solutions. The S600 portable system is now available for clients that require infrequent auditing anywhere in South Africa, or clients may elect to install a permanent S601 fixed system.
Air flow testing
On many sites, compressors are often not operated at full capacity. By logging the flow and the power from the compressors, facility managers will be able to determine a base load for the flow required in a plant. With detailed information main load compressors can be selected from an existing fleet with a variable speed drive compressor topping up the flow requirements. This type of decision will use power more effectively and cut energy wastage and costs.
Air velocity
Compressed air velocity can be a useful pointer to the efficiency of a pipeline and/or distribution system.
High velocities = pressure drops = wasted power
High velocities will carry airline contamination to the point of use.
Discharge pressures, on occasions, get increased to overcome a poorly designed/overloaded piping system. This then in turn demands more power, pushing up maintenance costs and wasting kW.
Leak detection
Ultrasonic Air Leak Detection demands a methodical approach. The survey should identify the leak location points, the volume of compressed air lost and the cost of the air wastage. This is presented in a readable, easy format.
The S331 can monitor your facility 24/7 with multiple instruments, such as flow, pressure, dew point, power and even cooling water flows.
A blocked condensate drain, an open bypass valve, or a fractured heat exchanger are potential causes of water pollution in a plant. Compressed Air Dryers can pollute an airline for days before the cause of the pollution is located and rectified. A dew point probe behind the dryer identifies a water contamination problem faster than any machine minder. These probes can easily be linked to an S331 and then to a SCADA system. An S331 covers all the essentials and provides the information in one concise graph.
Auditing capacity
Make sure your chosen auditor has the capacity to monitor all areas simultaneously to ensure a total overview of the facility within the same time frame and has the training and experience to provide the services that you demand.
Auditing is a science
Auditing has become a science that requires a substantial monetary investment in equipment to provide a comprehensive overview for a client, which includes monitoring to ISO 8573. Auditors must have the ability, experience, and knowledge to analyse and interpret the data to provide a meaningful report to the client.
Allen Cockfield is the CEO of the family operated specialist air treatment company, Artic Driers International a leading importer of quality air treatment products including the SUTO iTEC brand.
