Compressed air systems are indispensable for many industrial applications, powering machinery and driving operations across multiple sectors. One commonly overlooked strategy for improving these systems lies in a simple yet powerful tool: drawings. Detailed illustrations of the system can reveal significant insights into its operational efficiency and potential problem areas. Surprisingly, the practice of sketching out these systems is often neglected, sometimes leading to misdiagnoses of technical issues that become evident once visually represented.
Demand Side: Seal Air for Conveying Pumps
A case in point was a plant in Europe using two dilute phase conveying pumps. These pumps required seal air to protect their motors and outboard bearings. The air could either come from the pump conveying system or from compressed air, and piping was set up to use either source. A comprehensive drawing of this setup revealed a significant waste of resources and potential for catastrophic failure.
The "off" pump consumed compressed air through a partially open valve, wasting approximately 5,000 euros per year. Simultaneously, the "on" pump had all its air off, risking dust infiltration into its bearings, which could result in expensive repairs.
Once the problem was visually depicted, the required modifications became clear. Automating the feed air, regulating the compressed air, and adding a check valve to prevent feeding the low-pressure blower system could significantly reduce the plant's operational costs.
Distribution Side: Low Pressure Problem
Another plant was experiencing low-pressure issues. An initial inspection led to the belief that the piping system was to blame. To verify this, an auditor mapped the pressure drops throughout the system. Contrary to initial suspicions, the main problem lay in the individual branch lines, not the main loop. The drawing pinpointed the issues and clarified that no modifications to the main piping system were required, saving the plant from unnecessary expenditure and disruption.
Supply Side: Wet Air Throughout the Plant
A facility dealing with wet air throughout the plant called in an air compressor company to examine the problem. A quick inspection concluded that the issue lay with the dryer technology, leading to a recommendation for a $50,000 project that would increase operating costs by $20,000 to $30,000 per year. However, upon drawing the system, it became evident that the root cause was a misconnection between two systems, bypassing the dryer. A simple correction would have fixed the problem for $1,000 to $2,000 and decreased the operating cost by more than $10,000 per year.
Drawings: An Essential Tool for Optimization
These examples underline the importance of system drawings in diagnosing and addressing technical issues in compressed air systems. Whether the problem lies in supply, distribution, or demand, a drawing can simplify the analysis, making the issue and potential solutions obvious.
Nevertheless, many professionals, be they plant engineers, service technicians, sales engineers, or auditors, often skip this crucial step. Reasons may range from a perceived lack of time to an underestimation of the drawing's value in understanding the problem. However, the financial implications of missing this step can be severe, leading to expensive capital investments and significantly increased operating costs.
Edward R. Tufte's book, "The Visual Display of Quantitative Information", offers useful guidance for anyone interested in effectively conveying technical information graphically. The concept of maximizing "data ink" while minimizing "non-data ink" can help create clear, concise, and informative drawings. In other words, the most critical data should be emphasized, and anything not contributing to understanding the data should be reduced.
Drawings are more than just a sketch on paper; they are a powerful tool for diagnosing problems, understanding complex systems, and ultimately saving costs. Ensuring this practice becomes a fundamental part of the troubleshooting process can lead to substantial economic benefits and increased efficiency of compressed air systems across various industries.