A compressed air auditor was performing his work at a large mining operation. He and the site electrician were opening up the various machine electrical panels to enable power factor testing. Within seconds of opening one compressor panel, the electrician jumped back with fright and informed the auditor he was going to be a while. He had found a problem.
An industrial compressed air audit is a comprehensive evaluation designed to identify inefficiencies, optimize performance, and reduce energy consumption. The process begins with a thorough system analysis, reviewing the layout of compressors, piping, and end-use equipment. Key metrics such as air pressure, flow, temperature, and power consumption are measured to understand how the system operates under various conditions. Data is collected to assess energy use, monitor compressor duty cycles, and track demand patterns, ensuring the system matches the facility’s actual air needs.
One of the critical tasks in the audit is leak detection and efficiency evaluation. Leaks in piping, fittings, and equipment are identified using ultrasonic detectors and their impact on energy costs is quantified. Additionally, the audit examines pressure drops, dryer and filter performance, and inappropriate uses of compressed air. Tools and processes are scrutinized to detect “artificial demand” caused by excessive pressure settings or misuses like using air for cooling or cleaning.
Finally, the audit culminates in developing an actionable improvement plan. Recommendations may include right-sizing compressors, optimizing system pressure, implementing advanced controls like variable speed drives, and addressing maintenance needs. The audit also emphasizes prioritizing cost-effective measures and setting baselines to monitor post-implementation results. This structured approach not only helps reduce energy consumption and costs but also improves the reliability and lifespan of the compressed air system.
The auditor in this case had something extra to report. One of the site compressors had a main electrical input terminal that was very loose and had started arcing and burning the connecting bolt. If left in this condition, it would have let go during a compressor start — and possibly start an explosion.
You never know what might be found when doing a compressed air system audit!
The photo brings out the same problem I found a while ago: The overload relay/sensor was tripping for one of the five identical 10 HP, 3-phase feed pumps for a high pressure hydraulic system. The users had simply been adjusting the trip levels to keep running.Without shutting down, a clamp on ammeter revealed quite different currents among the three phases. Tightening the clamp nut almost a whole turn on one lug solved the problem.The foreman/supervisor had been clueless about the simple cause.