Industrial Utility Efficiency
Given that compressed air leak management programs are meant to save energy, reduce CO2 emissions, and generate ROI, DENSO’s Maryville, Tennessee, manufacturing facility can definitively say it has scored a trifecta when it comes to results – and reaped benefits beyond hard numbers alone.
In most industrial plants, data is everywhere. It resides in flow through pipes, pressure in tanks, vibration on rotating equipment, temperatures in heat exchangers, and electrical energy power consumption in motors. If we can acquire this data and make sense out of the patterns we can take actions to make our plants more efficient and reliable.
On a recent project, at a polyethylene terephthalate (PET) blow-mold and filling operation, a very effective measurement plan resulted in a full synchronization of the supply side air to blow molds with significant reduction in total air use and increases in productivity and quality.
To address a mandate for cutting operations energy usage at facilities by 25 percent without major capital expenditures, a major manufacturing company set its sites on better control of its compressed air systems. The project, implemented at 10 manufacturing plants over the course of three years, saves the company \$977,093 annually in energy costs – and was completed with zero out-of-pocket costs.
By finding a better way to control and manage its compressed air system, North American Lighting, Paris, Ill., has reduced its total compressed air energy use by 27 percent – and in the process – saves over 1,100,000 kWh/year for a total annual savings of \$91,000. The project also achieved a payback of less than one year.
A food processor in Western Canada hired an auditor to assess the energy efficiency of its compressed air system. The results revealed surprises about the operation of some important elements of the system, and detected that the air compressors were having control gap problems. Additionally, the audit led to initial energy savings of \$20,000 – and identified the potential to achieve overall operational savings of 45%. The following details some of the audit findings and results.
Machines for filling milk or juice must often work around the clock. Given the critical importance of uptime, Elopak opted for Aventics food-compliant pneumatics when developing its E-PS120A - the first fully aseptic filling machine for gable top packaging. With an output of up to 12,000 cartons per hour, disruptions and downtime are not welcome with the aseptic filling machine.
The University of Manitoba Bannatyne Campus, Canada, upgraded its compressed air system to include variable speed drive (VSD) air compressors and the use of internal heat-of-compression (HOC) drying, replacing oil-free air compressors and refrigerated dryers that reached the end of useful life. In doing so, the campus reduced annual energy consumption by 15%, improved the quality of the compressed air to modern day instrument air standards and gained additional compressed-air capacity. The local utility also awarded the medical campus an incentive of \$13,500, offsetting the cost of the initiative.
Whenever we start a compressed-air energy survey there are always two key topics plant personnel feel are paramount – leaks and reducing pressure. In this installment of our series on missed demand-side opportunities we’ll address the importance of compressed air system pressure.
Replacing unreliable air compressors is often a smart choice. Sometimes there is a better one. Take the case of a wallboard plant with two compressed air systems, including one for its board mill and another for its rock mill. Each had two 100 horsepower air compressors, all of which constantly overheated. When they did, plant personnel had to scramble to turn on a machine manually every time a unit shut down. Three units ran the plant so any shutdown had them walking on pins and needles.
Air Operated Double Diaphragm (AODD) Pumps are popular and versatile. Often, they also offer an excellent opportunity to lower the demand for compressed air, especially given the latest advances in controls and the energy savings to be realized.
