OEM Level Strategies for Conserving Compressed Air
Pneumatic powered equipment may be favored by food and beverage packaging OEMs for its low equipment cost and install complexity compared to electromechanically powered machines, but it’s not necessarily less costly to operate on an ongoing basis.
Besides compressed air being expensive to generate and purify, it’s also a utility that tends to be used inefficiently or wasted in manufacturing facilities.
According to an article in Plant Engineering, compressed air systems in the U.S. consume an estimated 30 billion kilowatt-hours per year, and account for $3.2 billion in wasted energy costs annually due to preventable maintenance issues and inefficient operations.
Additionally, compressed air production typically accounts for up to 40% of a facility’s total energy consumption.
Considering these facts, conserving compressed air presents outstanding opportunities for optimization and cost reduction. OEMs can help their customers do this by implementing a number of strategies and devices that will help manufacturers use their compressed air systems more efficiently.
Air Saving Devices
When compressed air is used in packaging facilities to blow debris off of items, dry parts, convey bottles, or in other blow-off applications, the air is typically discharged continuously, and much of it gets wasted.
However, there are new devices available that can convert this continuous air blow to a pulsed air blow, with no reduction in performance. These devices blow air in a series of on and off pulses. When the pulse is off, there is no air consumption, so fewer tank recharging cycles are required.
This pulsed air flow also offers a 40 to 50 percent reduction in compressed air costs when compared with the typical constant flow systems. There is also evidence that the pulsing action of the air improves the efficiency of air blow operations for drying and removing debris, and it reduces greenhouse gas emissions as well.
Manufacturers can also reduce air consumption and waste by using only the air they need for each process. OEMs can help by right-sizing valves and cylinders to avoid selecting combinations that consume more compressed air than necessary. Some vendors offer online and downloadable pneumatic sizing tools, such as www.parkerpdncalc.com, to help OEMs and their customers calculate air cost, flow, and product sizing.
Another strategy OEMs can employ is implementing regulators on air valves to match the air pressure needed by each machine with the amount of air pressure that gets delivered. Plant air pressures are often higher than individual machines require, and without these regulators the excess supply pressure delivered to equipment is wasted.
Similarly, reverse flow regulators installed between valves and actuators will reduce air pressure consumed on the return stroke of an actuator where workforce is not needed. This device, which can save a significant amount of compressed air, is appropriate for tasks where actuators need workforce only in one direction.
Another obvious but sometimes overlooked opportunity for conserving compressed air is simply preventing and addressing compressed air leaks. Common leak points are end joint fittings on air hoses, quick disconnects, or at the compressor itself. OEMs can help their customers look for and handle these leaks by including it as part of their regular maintenance plans.
Another OEM strategy is configuring pneumatic lines in ways that eliminate pressure stresses, particularly at joint areas. OEMs should also use presealed and straight fittings in builds wherever possible. Factory-applied thread sealants perform better than operator-applied sealants. And, if the install allows, straight fittings are preferable to elbow fittings when it comes to minimizing pressure drops.
Other strategies that OEMs can recommend to their customers are the use of specialized sensors. Some sensors detect pressure losses which may occur if compressed air is leaking from worn seals or elsewhere in the system. Others monitor air usage over time, letting manufacturers know whether air usage seems to be increasing, which could be another indication the system has a leak.
While OEMs may be reluctant to introduce many of these compressed-air-saving devices when a build is initially designed, for fear of increasing equipment costs, there’s no doubt their customers will be interested if these strategies can save them money in energy. For that reason, OEMs should market these strategies as unique selling features rather than sources of added costs.