Industrial Utility Efficiency    

Metals

Manufacturers familiar with the U.S. Environmental Protection Agency (EPA) ENERGY STAR® Energy Treasure Hunts initiative know it’s a great way to save energy and natural resources – as long as it’s done right – which is why some are turning to perhaps their best asset to achieve success: their unionized workforce.
Compressed air use in the metal fabrication industry is widespread. It is used to cool, clean, convey and coat a multitude of products and improve processes across the world. In fact, it is difficult to name processes in metal fabrication where compressed air cannot be found. A few processes where compressed air is used include: annealing and pickling, slitting, rolling, welding, stamping, punching, tube making, painting, finishing, turning, drilling, milling and sawing. Many of these processes and applications continue to use inefficient devices to deliver the compressed air, and — worse yet — many companies fail to recognize the simple implementation and significant payoff of improving compressed air efficiency.
EnSave, an energy auditing company based in Richmond, Vermont, recently performed compressed air audits at two facilities of a leading U.S. steel manufacturer. Both plants are mills that melt, cast, and roll steel to produce a variety of products, including: rebar, merchant bar, steel flats, rounds, fence posts, channel bar, steel channels, steel angles, structural angles and structural channels. These products are used in a diverse group of markets, including: construction, energy, transportation and agriculture. Compressed air is provided at 100 psig in both plants for a variety of applications — from optical sensor cooling to pneumatic cylinders for stacking finished products.
Quite a number of worst-case compressed air scenarios have been encountered over the years but none may compare to the conditions that existed in a metal foundry somewhere in North America. For reasons you are about to discover, we will not reveal the name of this factory or its location, in order to protect the innocent from embarrassment.
This metal fabrication and machining facility produces high-quality precision-built products. Over the years, the plant has grown and there have been several expansions to the current location. The company currently spends $227,043 annually on energy to operate the compressed air system. This figure will increase as electric rates are raised from their current average of 9.8 cents per kWh.
As you walk past the “sandblasting cabinet” back in the corner of the plant running alone and without the need for monitoring, does the thought of operational costs enter your mind? When it does, are you happy knowing the cabinet is automatic and does not need a full-time operator? Then, did you say to yourself, I wonder how much that abrasive media costs? How long does it last? Is this a more cost competitive alternative? Is there something that might last longer?
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.
Air gauging relies on a law of physics that states flow and pressure are directly proportionate to clearance and react inversely to each other. As clearance increases, air flow also increases and air pressure decreases portionately. As clearance decreases, air flow also decreases and air pressure increases.
International Wire Group, Inc. (IWG) headquartered in Camden, NY is the largest bare copper wire and copper wire products manufacturer in the United States with expanding operations in Europe. Products include a broad line of copper wire configurations and gauges with a variety of electrical and conductive characteristics , which are utilized by a wide variety of customers primarily in the industrial and energy, electronics, data communications, aerospace and defense, medical electronics and devices, automotive, and consumer and appliance industries.
Compressed Air Best Practices interviewed Doug Barndt (Manager, Demand Side Energy-Sustainability), Joseph Gress (Principal Engineer, Demand Side Energy) from Ball Corporation and Chris Gordon (Compressed Air System Specialist) from Blackhawk Equipment.  
“Sandblasting” is one of the oldest and most used methods of metal treatment. Various abrasive materials may be loaded manually or by a vacuum system pulling the “grit” from a storage tank. A control valve then operates with the compressed air (bypassing the vacuum pump), being forced into the tank pressurizing the receiver. When the high pressure compressed air goes out the discharge line, it pulls the appropriate amount of grit with it to effectively impinge against the targeted metal surface.