Industrial Utility Efficiency    

Air Compressors

In general, this article focuses on the definitions of terms often used to understand centrifugal air compressor performance. Comments are also made on how to measure power consumption. This article is not intended to be an engineering discussion of the various types and designs of centrifugal and other air compressors.
Most P.E.T. bottle-blowing machines require anywhere from 550 psig (38 barg) to 580 psig (40 barg) and an air flow of 247 cfm FAD (420 m3/hr) to 3700 cfm FAD (6290 m3/hr). The air compressor technology used most prevalently for this application is the double-acting, oil-free, water-cooled, reciprocating air compressor. With the higher pressures and air flows that are required, the P.E.T. bottle blowing market is a strong niche market for the double-acting oil-free reciprocating (piston) compressors.  
Several days prior to our visit, during a cold winter evening, the lead air compressor in one mechanical room tripped off (apparently due to a fouled intake filter and low air flow through the machine). A crucial situation then developed: The "stand-by" unit did not start. Maintenance folks had to be called in to get a compressor running. That delay caused low plant air pressure, production curtailment and some defective product. They had yet to determine the conditions that caused the "no-start".
Production processes get their energy from the air stored at higher pressure in the piping distribution system. The air compressors simply replenish the air that is consumed. It is an important distinction to make. The energy input in compressing the air is supplied to the connecting pipes for delivery to the various demands throughout the facility.
In the realm of pharmaceutical production and packaging, the two most important factors with compressed air are reliability and quality. In pharmaceutical plants, our customers have emphasized this reoccurring theme over and over to paint the clear picture that reliable and high-quality air are king.
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.