Recycled compressed air, the "low-hanging fruit" of energy conservation

However, there is some very tasty "low hanging fruit" available to those who use compressed air, thanks to a newly developed air recovery system. For industries such as blow molding of PET containers, this fruit is easy picking and highly rewarding. It has enabled some firms to gain some very lucrative rebates on electric power usage.

PET bottle molders, who use both high-pressure and low-pressure compressed air in their blow molding operations, typically exhaust all residual compressed air from the high-pressure side out into the atmosphere. This was probably considered unavoidable and not especially wasteful " until electric energy prices started going through the roof, especially in regions such as New England and California.

"Many of these PET container producers have begun to view air as the fourth utility, along with gas, water and electricity," says Chris Gordon, president of Blackhawk Equipment (Arvada, Colo.). "So, you try to save money on compressed air in plants like these because they can theoretically net out some big energy savings. The question is, what technological development is going to enable you to do that?"

An air systems specialist and certified by the Dept. of Energy as an Air Master Plus certified consultant, Gordon takes care of the compressed air needs at many of the worldwide locations of container giant Ball Corp. Some of these locations produce PET beverage bottles, and use a lot of compressed air and energy in the process.

Three years ago Blackhawk Equipment was introduced to a new concept in recycling compressed air, the Air Recovery System (ARS). Developed by Technoplan Engineering SA of Geneva, Switzerland, the ARS essentially recovers compressed air that still has residual, albeit lower pressure, available. Gordon saw immediately that the ARS concept could be advantageous to the Ball Corporation PET bottle production operations, so he began to work with the licensed U.S. distributor of the system, Connell Industries (Rahway, NJ).

The ARS system is installed between a blow molder's exhaust system and that plant's low-pressure air system, capturing and storing almost half of the dry, oil free air at a pressure of 12 bar (170psi).

The ARS system returns reclaimed air to the plant's low-pressure air system to be used as needed anywhere within your facility that allows some compressors to rest, resulting in significant savings in energy and maintenance expenses.

"The PET molding process is semi-wasteful one that requires ultra-high pressures," in excess of 580 PSIG Gordon says.

"For the past several years Ball Corp. has been very focused on energy savings. Compressors are the largest motors in any of their facilities, consuming millions of dollars worth of electric power every year. So, anything we can do to save energy is what we are focused on, especially if there is the potential for major energy savings like with the ARS concept."