Industrial Utility Efficiency
Operating the vacuum system at higher levels (then necessary) affects the needed volumetric flow to compensate for leaks. This required compensation of volume (ACFM) must be added to the nominal production flow demand. The ambient air leak into the system will expand to the highest vacuum level, which is known as the “Expansion Ratio.”
Bottling companies and breweries, in California, are benefiting from a three-step system assessment process aimed at reducing the electrical consumption of their compressed air systems. The three-step process reduces compressed air demand in bottling lines by focusing on open blowing and idle equipment, and then improves the speci c power (reducing the energy consumption) of the air compressors.
The Focus on Energy Water and Wastewater Program was developed to support the industry because of the enormous potential to reduce energy use without compromising water quality standards. Through the program, numerous water and wastewater personnel have learned that energy use can be managed, with no adverse effects on water quality. Most locations that have saved energy have found improved control and treatment.
Many times, the hierarchy of making improvements in your compressed air system will begin with the larger equipment. If your compressor is outdated, inefficient or sized improperly for your plant, the cost of replacing it may scare you away from proceeding down the efficiency path. It is also typical to first concentrate on updating the controls of a compressor to best match peak demands and lulls in the need for air and, while this is a very good step to take in your overall plan of attack, it can also burden your budget.
In thermal power stations, nuclear plants, and chemical and industrial plants, different types of bulk materials are used. The materials exist in different forms including lump, powder, granules, chips, and pallets. These bulk materials, in their different forms, require efficient and reliable material handling systems.
In many manufacturing operations, a very significant compressed air use is pneumatic conveying of many types of materials such as cement, fly ash, starch, sugar, salt, sand, plastic pellets, oats, feeds, etc. Often these are systems that use high-pressure air (100 psig class) reduced to lower pressures (15 psig, 45 psig). This creates an air savings opportunity.
There are a variety of means factories can use to remove or “blowoff” moisture from a package. Open tubes or drilled pipe are often viewed as simple low-cost methods. However, there are considerable drawbacks to these approaches, most notably – increased operating expense. While they may be convenient and inexpensive in the short term, these approaches often cost 5-7 times more to operate than preferred alternatives.
Recently, The Kroger Company’s Indianapolis bakery identified the use of compressed air in a blow-off and conveyor gap transfer as a major source of energy loss and cost waste. According to the U.S. Department of Energy, “inappropriate use” of compressed air like blow-off produces high pressure atmosphere bleed leading to significant energy loss and unnecessary operational costs. Carrying a 10-15% efficiency return (according to the Department of Energy), compressed air applications can often be achieved more effectively, efficiently and less expensively with alternative solutions using a high flow rate and moderate pressure.
A new cogeneration system installed at the Budd Inlet Treatment Plant by the LOTT (Lacey, Olympia, Tumwater, and Thurston County) Clean Water Alliance late last year uses treatment by-products as fuel to generate electricity and heat energy. This renewable energy system, combined with an aeration blower retrofit currently underway at the Budd Inlet Treatment Plant, is expected to save LOTT more than $228,000 per year in utility costs.
A leading soft drink bottling manufacturer’s compressed air needs were threatening to exceed its Michigan plant’s compressed air capacity. Faced with the cost of buying a new compressor, the soft drink bottling manufacturer re-assessed their compressed air use to identify compressor and energy savings opportunities. In the audit, the soft drink bottling manufacturer identified the use of compressed air in a gap transfer as a source of compressed air and energy inefficiency.
A compressed air system assessment saved this building materials manufacturer over $518,000 per year in energy costs, with a simple ROI of 11 months.
