Industrial Utility Efficiency    

Air Compressors

There are many choices of compressor technology and types of controls that can be used for variable demands. Some examples are rotary screw compressors with inlet valve control: variable speed drives: load/unload control; or centrifugal compressors with variable inlet guide vanes. However, in many cases, the efficiency of the overall compression process can be reduced significantly during lower flow demands, leading to more power per unit of air flow being delivered. It is very important to evaluate different available options and see how a plant can run most efficiently.
Located in the bowels of most hospitals, you will find the source of the Level 1 Medical Air compressed air system. Per the NFPA Section 99 Specification (National Fire Protection Association), Level 1 air compressor systems provide air for human consumption within the hospital facility.
Roxane Laboratories, Inc., a subsidiary of Boehringer Ingelheim Corporation located in Columbus, Ohio, created a world-class air system that generated $61,314 per year in electrical energy cost savings (1,156,868 kWh), improved productivity and quality, and allowed the successful completion of a significant plant expansion.
This aluminum mill spends $369,000 annually in energy costs to operate their compressed air system. This system assessment recommends actions reducing annual energy costs by $120,000 and improving productivity and quality by delivering clean, dry compressed air.
A paper mill in Wisconsin reduced its’ yearly water consumption by 547.5 million gallons and reduced its’ yearly air compressor maintenance costs by $470,000.  
This article reviews two major processes in paper mills: compressed air quality and air compressor cooling.  The central air compressor room was expanded and relocated at the largest privately owned paper mill in Canada.  The compressor space was required by a plant expansion, which would occupy the original compressor space for increased production.
Compressed Air Best Practices® interviewed Mr. Sid Van der Meer and Mr. Terry Nickel from Northwest Equipment Ltd in Airdrie, Canada.
There are many applications which require a low horsepower compressor built with the technology that has been proven in larger compressors. Often these situations are not addressed well by the general compressor industry.  
This factory currently spends $735,757 annually on the electricity required to operate the compressed air system at its plant. The group of projects recommended in the system assessment will reduce these energy costs by an estimated $364,211 (49% of current use). Estimated costs for completing the recommended projects total $435,800. This figure represents a simple payback period of 14.4 months.
Compressed air leaks - every system has them.  Is a leak identification and control program economically rewarding and/or necessary? Upper management sometimes doesn’t recognize the true cost of not repairing air leaks.  Knowing the high cost of compressed air, why wouldn’t every facility with a compressed air piping system implement a continuous leak identification and repair program?
This article presents a case study of Grimmway Farms; a carrot growing and packing firm located in California’s Central Valley that was able to improve its compressed air system efficiency after implementing system automation and making relatively small equipment and piping changes.