Industrial Utility Efficiency    


One of the most common problems in plants is low air pressure. One of the most common solutions is to purchase new air compressors. Often this advice leads to a poor return on investment with the company’s hard-earned money. Often the issues are related to demand, distribution, or both. Solving the wrong problem can be expensive from a capital and operating cost perspective. Determining root cause analysis may cost more up front, but will save tens if not hundreds of thousands of dollars long term.
While control storage was originally an integral component of a reciprocating air compressor installation, this article will only briefly explore that application. The content of this article will focus instead on rotary screw installations since the rotary screw air compressor has essentially replaced the reciprocating as the compressor of choice in industrial applications. It should also be noted that in compressed air systems where reciprocating and rotary screw air compressors are operating together, control storage should always be utilized.
This food container plant spends $1,028,672 annually on energy to operate the compressed air system at their facility. This figure will increase as electric rates are projected to be raised from their current average of 6.2 cents per kWh. The set of projects identified in the compressed air system assessment could reduce these energy costs by $616,000 per year (49%). Estimated costs for completing the supply and demand-side projects total $525,000. These costs are offset by having qualified for utility company energy incentives of $425,000. After the incentives, this project delivered a simple ROI of two (2) months.
This article describes a compressed air retrofit project implemented at Kellogg’s Eggo factory located in San Jose, California. Kellogg’s continues to realize both annual energy savings and quality improvements because of the upgrade. In addition, Kellogg’s received a substantial utility incentive from Pacific Gas and Electric Company, which was based on the achieved energy savings.
Power Smart® efficiency measures for compressed air systems at Tolko’s paper mill and sawmill at The Pas are saving the company more than $125,000 a year.  
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.
Pneumatic air cylinders play a major role in allowing a modern sawmill to produce at the high-speed production rates required. Stable air pressure is critical to allow the air cylinders to respond in a timely manner and avoid any production delays.
We conducted a comprehensive compressed air system assessment. Opportunities to improve the system were found in the main piping system, in reducing pressure losses in the mold machine piping, and with the high ambient temperatures found in the compressor room. We estimated energy savings of 403,500 kWh per year for a power savings of $65,000 per year. The total projects costs were $48,000 for a simple ROI of nine (9) months.
An industrial manufacturing plant (producing commercial water meters and valves) had engaged us to conduct an ‘on-site’ Energy & Utilities Assessment of their facility. The annual ‘spend’ for electricity, natural gas, fuels and water was about $ 2.0 million.
In many industrial plants there are one or more applications with intermittent demands of relatively high volume. One example is the use of dense phase transport systems to convey the cement. Dense phase systems can cause severe dynamic pressure fluctuations affecting quality of the end product in a plant.
Sitting on his desk the day Brian began his new job as Plant Engineer for Carbo Ceramics’ McIntyre, GA facility was a proposal to purchase a new 150 HP air compressor as a backup machine. The facility already had six of these machines and, yes, all six ran almost continuously.