Compressed air is a vital plant utility, since virtually every phase of manufacturing depends upon it. A compressed air system can be expensive to operate compared to other plant utilities. Since it takes 7 to 8 horsepower (hp) of electrical energy to produce 1 hp of effect at the end user point, efficiency is very important. Because of this, you must choose systems and deal with operational matters carefully.
Compressed air system optimisation can lower costs from 30 to 60 percent according to case studies referred to in the June 2001 U.S. Department of Energy study, Assessment of the Market for Compressed Air Efficiency Services. According to this Assessment, compressed air accounts for 10 percent of all electricity consumption and roughly 16 percent of all motor system energy use in U.S. manufacturing industries.
A compressed air system has of three parts:
- production and cleanup
- the user.
To attain maximum efficiency, you must treat all three as part of a whole. The best way to do this is by auditing the system, analyzing all three parts as a system
First, audit the end use. “How?” and “Why?” questions can uncover wasteful practices, poor usage and unsafe operation. Revising procedures and introducing new processes to eliminate wasteful practises can save much money.
Second, audit the air distribution. Here, piping, tubing, valves, hoses, filters, quick connectors and other devices transmit compressed air to the end use. Leaks and pressure drops create losses and reducing these losses often results in significant savings.
Third, audit production and cleanup. This area typically has compressors, compressor control systems, air dryers, one or more receivers, filters and other components. Improving production and cleanup can save more energy at the distribution and end use stages. Indeed, the improvements can be as simple as choosing the most efficient compressor operating mode.
Applying energy efficiency measures can save a facility thousands of dollars and payback on projects is typically under two years.
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