The load on any compressed air system — and the flow that must be produced to maintain pressure — contributes to the cost of operation. A good strategy to follow in trying to reduce compressed air costs is to examine the end users of the system and determine if they are classed as “appropriate” or “inappropriate.”
An inappropriate compressed air use could be one that uses too much compressed air, or could best be supplied with energy from some other source. This usually involves lower cost drivers like hydraulic, direct drive electrical, or low pressure supply. Why not use compressed air? Because compressed air energy costs at least 8 times as much as, say, a direct drive motor. It’s a matter of economics.
Uncontrolled blowing with compressed air is a common inappropriate use. These types of uses may be inappropriate because they may be using more compressed air than required due to:
- Poor design of the nozzle,
- Nozzle erosion due to age,
- Use of unregulated high pressure air,
- Continuous blow even when not required
- Use of blowing when low pressure is available
The nozzle in the photograph above right is a poorly homemade unit that has been damaged by corrosion and runs 24 x 7 — consuming 32 cfm and costing $5,600 per year in compressed air costs! Similar nozzles are available that would consume about 10 cfm. The 10 cfm could be reduced to 8 cfm if the pressure was regulated to the nozzle. And this nozzle is not required to blow when the production line is not running, estimated at about 40% of the time.
Potential savings in addressing these deficiencies are 85%, worth $4,760 in operating costs per year. There are six similar nozzles in the plant with a potential of $28,500 — about 25% of the total compressed air costs in the plant.
This represents a significant savings for the owner of the nozzles. How much could you save? It may be time to examine your blowing devices in your plant!