Sistemas de ar comprimido

Steam

Motors

Compressed Air

Determine the Cost of Compressed Air for Your Plant
Suggested Actions
• Determine the cost of compressed air for your plant by periodically monitoring the compressor operating hours and load duty cycle.
• Use a systems approach while operating and maintaining a compressed air system.
• Adopt a plant-wide compressed air management policy to cut costs and reduce waste by eliminating inappropriate uses, fixing leaks, and matching system supply with demand.

Most industrial facilities need some form of compressed air, whether for running a simple air tool or for more complicated tasks such as operation of pneumatic controls.
A recent survey by the U.S. Department of Energy showed that for a typical industrial facility, approximately 10% of the electricity consumed is for generating compressed air.
For some facilities, compressed air generation may account for 30% or more of the electricity consumed. Compressed air is an on-site generated utility. Very often the cost of generation is not known; however, some companies use a value of 15-30 cents per 1000 cubic feet of air.
Compressed air is one of the most expensive sources of energy in a plant. The overall efficiency of a typical compressed air system can be as low as 10-15%. For example, to operate a 1 hp air motor at 100 psig, approximately 7-8 hp of electrical power is supplied to the air compressor.
To calculate the cost of compressed air in your facility, use the formula shown below:
Cost ($) =

(bhp) x (0.746) x (# of operating hours) x ($/kWh) x (% time) x (% full load bhp)
Motor Efficiency

References
Improving Compressed Air System
Performance: A Sourcebook for the
Industry, Motor Challenge and
Compressed Air Challenge,
April 1998.

where bhp—Compressor shaft horsepower (frequently higher than the motor nameplate horsepower—check equipment specification)
Percent time—percentage of time running at this operating level
Percent