Industrial Utility Efficiency    

Compressor Controls

Quite often the typical variability in compressed air flow demand does not proportionately translate into power reductions at the air compressors. This can be a result of numerous problems with the compressed air supply system. It is important to understand the supply-side’s ability to respond to the demand-side of the compressed air system. If the air compressors, on the supply-side, are not able to translate flow reductions into energy savings, implementation of demand reduction projects should be re-evaluated.  
“First there are the old conventions. The majority of compressor houses still employ fixed speed compressors and a cascaded pressure switch control system. This arrangement will be familiar to many, but it is outdated and inefficient, and needs to be changed. There is a comfort factor with familiar technology, which is exacerbated by constant time pressure due to other day-today responsibilities and a lack of information and good advice on what can be achieved.”  
A Tier 1 automotive plant was spending $364,259 annually on electricity to operate their compressed air system. This figure was expected to increase as electric rates were forecasted to rise from their current average of 7.16 cents per kWh. Our firm, Air Power USA, conducted a full supply and demand-side compressed air system assessment. The set of projects recommended by the assessment, would reduce these energy costs by $218,670 or 60%.
“Compressed air systems with multiple compressors operating to supply demand requirements present unique challenges in compressed air system control schemes.”
The $mart Sequencer® is an air compressor control system designed to reduce a plant’s energy costs by continuously monitoring system demand and automatically selecting the most energy efficient combination of available air compressors.
Compressed air system controls match the compressed air supply with system demand and are one of the most important determinants of overall system energy efficiency. This article discusses both individual compressor control and overall system control of plants with multiple compressors. Proper control is essential to efficient system operation and high performance.  
The goals of this article are to show why sequencers often have problems, and to demonstrate how avoid problems by proper system integration and controls design.
When was the last time you visited your compressor room? A week ago? Several weeks ago? If you are like many, you went in for the last scheduled maintenance interval and have rarely been back since. Air compressors, dryers and other air system components have become more reliable and self sustaining from a maintenance standpoint with each generation, requiring less and less human intervention.
The purpose of this article is to investigate the cause and effect that can occur when you reduce demand with no supply changes and the alternative which will produce positive, long term results which you can take to the bank.
This textile plant uses compressed air in their knitting, sewing, and dye house operations and needed a system designed for the significant fluctuations in demand. Compressed air demand profiles were placed into four segments; 1st shift peak demand and minimum demand, and 2nd shift peak demand and minimum demand.
Compressed Air Best Practices interviewed Mr. John Malinowski, Senior Product Manager-AC Motors, Baldor Electric Company.