Industrial Utility Efficiency    

Air Compressors

By far the most important development in the world of screw type air compressors has been the introduction of variable speed control using electronic variable frequency drives (VFD’s). Systems that run with at least one air compressor at part load can almost always operate more efficiently if a well-controlled VFD is added to the system. But what if a system has two or more VFD units? This article discusses the challenges in controlling multiple VFD air compressors with some suggested solutions.
Production complains about frequent work stoppages due to air supply related problems. It wants a more reliable consistent source of compressed air. Maintenance says it will need to replace an older compressor with a new one to improve the reliability and stability of the system. Maybe purchase a bigger one than currently needed in anticipation of future increases in air demands. Management wants assurances a good return on the investment will be realized from the expenditure before making a financial commitment. For comparing and evaluating alternatives, a benchmark must be established to determine the cost to run the current system. An assessment must be performed to identify the saving’s opportunities and assign dollar values. Questions about the cost of the assessment and what is to be expected in return need to be answered.
As an industrial distributor for 65 years, C.H. Reed, Inc. has been providing ideas, concepts and sustainable solutions to help manage issues associated with three key areas of industrial plants: compressed air systems and equipment; assembly tools and ergonomic material handling; paint finishing and fluid handling equipment. Compressed air has always been a strong focus for C.H. Reed, and it’s a common thread running through all of its product families.
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.
When the topic of discussion is making ice cream, the first thing that comes to mind isn’t heat, but at Nestlé’s Ice Cream factory in Tulare, California, heat is recovered from air-cooled air compressors to heat process water. “Right out of the gate, everything is pneumatic,” explains Tom Finn, Project Engineer with Nestlé Ice Cream Division. “Air cylinders and air driven motors, the process piping valves which divert, route, stop/start, and mix process fluids, our packaging machinery including rejection, cleaning and vapor removal processes, all of these rely on compressed air.
Compressed Air Best Practices® Magazine interviewed Dr. Jay Varadaraj, (Managing Director) of ELGi Equipments Ltd. ELGi today is one of the world’s leading manufacturers of air compressors. Like most companies, however, it started with one ambitious person. My grandfather, Lakshminaickenpalayam Govindaswamy (this where the “L” and “G” in ELGi come from) was a bus driver for the British in 1918. He purchased one bus and proceeded to build a fleet peaking at 300 buses. He believed he was in the transportation business so he entered the airline business ultimately withdrawing however when this industry was nationalized.  
Boeing Canada Winnipeg (BCW) has been recognized with the best improvement project of 2013 within the Boeing enterprise worldwide. A cross-functional project team including BCW staff, Manitoba Hydro technical support, and design engineers from Alliance Engineering Services, Inc. used innovative high-pressure storage to reduce the required size of their air compressors and save substantial utility energy and demand charges.
Most of us understand each individual has a unique DNA combination. Compressed air is very similar, each compressed air system should be uniquely designed so the system performs in harmony. Properly managing the compressed air system requires an investigative audit to understand the nuances of the system and identify the most effective solution(s) for efficiency. Not investigating the system, before selecting improvements, would be like consenting to surgery without having an exam. Yet, this frequently occurs in businesses operating compressed air systems.
Northwest Pump & Equipment was founded in 1959 - opening three branches on the same day in Portland, Seattle and Spokane. The business focus was to distribute petroleum equipment for the oil and gas market – primarily to service stations and oil jobbers. In-ground fuel tanks, hoists, lubrication equipment, lighting, farm pumps, air compressors and other gas pumping equipment were our primary product lines back when there were “Full-Service Gas Stations”. Over the years, this successful business model was expanded so the Company did business in California, Hawaii, Washington, Alaska, Arizona, Nevada, Idaho, and Montana.
This is a corn mill processing cornstarch, sugar, and other byproducts. Ambient air is contaminated with extremely high levels of dust due to the manufacturing processes and material handling. Average electric rates at the plant are $0.04 / kWh. The actual plant electric cost for compressed air production is $553,630 per year.
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.