Industrial Energy Savings    

System Assessment

This facility is part of a major corporation with dozens of manufacturing facilities where consumer good food products are processed and packaged for shipment to retail outlets. The factory was spending $210,000 annually on energy to operate their compressed air system. This system assessment detailed four (4) project areas where yearly energy savings totaling $100,855 could be found with an investment of $100,000.

Compressor Controls

Based on the air system operating 8,760 hours per year, the group of projects recommended below could reduce these energy costs by an estimated $170,718 or 56% of current use.  In addition, these projects will allow the plant to have a back-up compressor and help eliminate the rental expenditure for compressor maintenance or downtime.

Piping Storage

The Compressed Air Challenge® Fundamentals and Advanced training discuss the benefits of using central controllers to efficiently control system compressors. These systems are called “System Master” controls. Modern day System Master Controls use advanced technologies to network air compressors in a preprogrammed sequence. A properly configured network with the right size and type of trim compressor can typically hold the supply air pressure in a tight band of +/- 2 psi. Because of this capability, many users feel the application of System Master Control negates the benefit of applying Pressure-Flow Control to stabilize the plant air pressure.

End Uses

Stretch blow molding equipment requires a significant amount of energy—both compressed air and electrical—to produce bottles. Creating an effective and efficient process, as well as monitoring and maintaining optimal process settings, can result in significant energy cost reduction. These efforts will also help produce containers that meet all of the required quality standards.

Pressure

Energy conservation measures (ECMs) associated with compressed air have received a significant amount of attention over the years, mostly due to a reasonably short financial return compared with other energy-consuming equipment. Over time, many of the recommended corrective actions to reduce compressed air energy consumption were simplified so much that they did not lead to positive results. One of the most common compressed air ECMs is reducing system pressure, and it leverages the best practice calculation —.5 percent power per psi — outlined in the Department of Energy’s Compressed Air Challenge. This article highlights more common issues associated with estimating energy conservation resulting from changing system pressure.

Air Treatment/N2

This northeastern U.S. automotive manufacturing facility spends $269,046 annually on energy to operate their compressed air system. This figure will increase as electric rates are raised from their current average of .019 cents per kWh. The set of projects, in this system assessment, reduce these energy costs by $110,166 or forty percent. Reliability of compressed air quality, however, is the main concern in this plant and the primary focus of this system assessment.

Leaks

This article reviews portions of an audit report commissioned to survey the condition of a compressed air system in a factory located in the U.S. The objective of this study is to determine the current operating conditions and make recommendations for improvement based upon application of industry recognized best practices. Due to article space limitations, this article will focus on portions of the over-all audit report provided to the factory.

Pneumatics

Currently, and for good reason, much attention is being focused on the conservation of energy. Compressed air, like electricity and gas, is an energy resource. It has often been referred to as the third utility. As with all energy sources, our global environment demands that it be conserved and used wisely.

Vacuum Blowers

Every municipality and utility is facing the reality of rising energy costs. In 2010, the Town of Billerica, MA, which is located 22 miles northwest of Boston with a population of just under 40,000 residents, engaged Process Energy Services and Woodard & Curran to conduct an energy evaluation of the Town’s Wastewater Treatment Facility (WWTF) and pump station systems sponsored by National Grid. The objective of the evaluation was to provide an overview of each facility system to determine how electrical energy and natural gas were being used at the facility and to identify and develop potential costsaving projects.
This paper mill currently spends $1,747,000 annually on energy to operate the compressed air system at their plant located in the southwestern region of the U.S. The set of projects recommended, in this system assessment, could reduce these energy costs by $369,000 or twenty-one percent (21%). Estimated costs for completing the projects total $767,900, representing a simple payback of 25 months. More importantly, these projects will improve productivity, quality and maintenance costs - many associated with poor compressed air quality.
Based on the air system operating 8,760 hours per year, the group of projects recommended below could reduce these energy costs by an estimated $170,718 or 56% of current use.  In addition, these projects will allow the plant to have a back-up compressor and help eliminate the rental expenditure for compressor maintenance or downtime.
The development of extruded aluminum piping is a recent innovation in the compressed air industry. The internal bore of this piping is smooth and corrosion resistant which makes the pressure differential characteristics of a straight run of this pipe superior to that of steel pipe. Because it is much lighter than steel pipe the installation is much easier. And the manufacturers of this style of piping have come up with various twist lock connectors to make the installation even simpler.
This food & beverage plant is a large (500,000 sq ft) meat processing plant with twenty packaging lines and nine palletizers. The compressed air system is supplied from three separate rooms with seven individual lubricant-cooled, single and two-stage rotary screw compressors. The plant has four blower purge desiccant dryers designed to deliver a - 40°F pressure dewpoint.
Proper compressed air supply to the IS Machine, in glass container manufacturing, is critical. Each process requires carefully controlled pressure, air quality (dryers), and flow as necessary for optimum production with minimum scrap. Most IS machine operations, which Air Power has reviewed over the years, offer significant energy savings opportunities with low capital costs. The final results also enhance quality and productivity.
This glass bottle production plant had a complete compressed air audit in 2001 and 2002 at which time many successful projects reduced and stabilized the demand at 3,148 scfm at 95 psig for the high pressure system air and 9,300-9,500 scfm at 58 psig for the low pressure system. Successful application of an oversized 7,200-scfm rated cycling refrigerated dryer completely dried up the high-pressure air, allowing the removal of several non-performing desiccant dryers and savings in direct kW and purge air.
The Technical Director of a large facility in the Mid-West (producing valves and meters) hired us to assist with a Site Energy & Utility Systems assessment. The compressed air system quickly became one of the main issues identified. The plant was built in the 1960’s and had expanded over the years. Recent reduction-in-force programs (to reduce costs) had impacted the maintenance department and the plant air system was high among the systems that were the most affected. Over the next several months, as management became attuned to all of the air system issues affecting utility costs and process quality concerns, resources were provided and significant improvements occurred.
TIGG Corporation, a manufacturer of activated carbon adsorption vessels, custom air receivers and other steel tanks and pressure vessels, substantially reduced its energy costs after implementing equipment, labor consolidation and procedural changes resulting from a compressed air energy audit. The audit was performed at TIGG's 155,000 square feet manufacturing facility in Heber Springs, Arkansas to determine the efficiency of the existing compressed air system and to set a baseline for TIGG's participation in Entergy Arkansas’ Large C&I Custom Incentive Program.
Not long ago most air compressors were controlled with mechanical pressures switches, relays and gauges. The setup of these units, especially when attempting to coordinate multiple compressors could be a frustrating and fruitless experience because often, no sooner than the controls were correctly adjusted, some sort of mechanical gremlin would throw something out of adjustment again.
The advent of manifold mounted, plug-in pneumatic valves has been a boon for machine builders. It allows them to mount complete valve packages in a safe and secure location on a machine. Using a D-sub connector, serial interface module, or similar single-point wiring system, all of the electrical control outputs can feed into one location on the manifold, greatly simplifying the wiring. Plumbing issues are reduced, since a single air pressure line can be used to feed a common pressure gallery. The same advantage applies to the common exhaust gallery. No longer would both a plumber and an electrician be required to replace a valve, since any valve can be replaced without disturbing electrical connections or plumbing lines.