Six Ways to Boost the Energy Efficiency of Your Pneumatic System
With a global focus on sustainability, resourceful manufacturers are finding inventive ways to slash their carbon footprint and, at the same time, their electric bills. Unfortunately, pneumatic systems, which provide the compressed air to drive machine tools, painting booths, material handling equipment and other machinery throughout the manufacturing industry, are often overlooked in efficiency efforts simply because most users believe that inefficiency is just a part of the performance. While U.S. Department of Energy (DOE) statistics show that the compressed air systems that power pneumatically driven equipment account for 10% of all electricity usage in U.S. manufacturing industries, they also suggest that more than 50% of all industrial plant air systems present opportunities for sizable energy savings with relatively low project costs.
While it might be surprising that significant improvements to pneumatic system efficiency can be made with a few minor tweaks and low-cost maintenance activities, the DOE states that “system optimization programs” can provide savings between 30% and 60% of initial system usage. Briefly discussed here are six simple ways to help optimize operation and improve the energy efficiency of your facility’s pneumatic system.
1. Minimize Leaks
U.S. DOE statistics reveal that the average manufacturing plant loses 30% to 45% of its compressed air due to leakage. While this is a startling figure, most leaks can be prevented or repaired. In most facilities, there is likely no shortage of leaks between the compressor and the various loads, but the most common leakage areas will be valves and deteriorated seals.
Further, standard seals often degrade in applications where stress, contamination, temperature extremes or dampness occur. In these applications, extreme-service seals such as those made of Viton, Teflon, polyurethane or other robust materials might perform better, while also reducing leaks and increasing efficiency.
Technologies, including flow sensors and acoustic leak measuring devices, together with system efficiency audits can be used to detect leaks throughout the pneumatic system so maintenance crews know where to find the greatest opportunities for stopping leaks.
2. Optimize Compressor Operation
While detailing the methods used to increase compressor efficiency are too broad for the scope of this article, more comprehensive information can found here. However, there are some simple tasks that can be performed until larger projects can be accomplished.
Analyzing the load profile and restricting artificial demand, such as supplying more pressure than is needed to tools or equipment, is a good place to start, as any pressure above the requirements of the application is wasted energy. See more on optimizing pressure below.
Because air compressors draw in air to function, the condition of the air impacts the efficiency of the system, making adjustments to intake air can make a big difference in energy consumption. Factors of concern include air temperature, air cleanliness and humidity. Keep in mind that cooler air requires less energy to compress than warmer air, clean air moves with less effort throughout the pneumatic system and dry air will help prevent component damage. Having the coolest, cleanest and driest air possible will enhance efficiency of the compressed air system. The key to achieving this is through the correct installation of filters, aftercoolers, dryers and regulators that meet the system and application requirements.
3. Right-Size Components
Since each component in a pneumatic system impacts the other parts, as well as the overall system efficiency, it’s important to ensure that properly sized components that meet system and application requirements are used. One way to do this is to establish the requirement from the demand end in order to determine the correct sizing of air treatment components and accessories. Pay close attention to the sizing of pneumatic piping and connections as limiting variations in pipe and connection sizing and reducing the number of fittings can help reduce pressure drop. Using appropriately sized air treatment components can also eliminate changes in pressure, while correctly sizing and positioning actuators lowers air consumption. And using control valve technology that both meets the system requirements and is appropriately sized for the needs of the demand will help create energy savings.
4. Optimize Pressure
It’s not uncommon for system designers to create a system that delivers more pressure than is needed, nor is it unusual for operators to increase pressure under the false pretense that applying more pressure will improve performance. However, supplying more pressure than is required will unnecessarily use more power than is necessary.
There are several ways to ensure that proper pressure is used throughout the system. First, ensure the distance between the air compressed air supply and actuators is optimal and that the hose and conduit connections are as short as possible. Reducing lengths of tubing between components increases machine efficiency because the system doesn’t have to work as hard to move the air through the system. Another quick fix is replacing worn hoses to prevent leaks that waste energy.
Installing pressure regulators or other devices that keep air at a constant, appropriate pressure can help ensure that artificial demand remains as low as possible.
5. Turn It Off!
It should be obvious, but air, and thus power, is wasted when idle air-operated machines are left pressurized. It’s the equivalent of leaving a light on when no one is in the room. While some components or system elements do require a small amount of pressure even after the machine is turned off, this is not always the case. To ensure that enough pressure is delivered to those applications and that air is not being supplied to machines that don’t need it, automatic air reduction controls can be added and will serve to lower the air pressure to appropriate levels or cut it off as needed. The energy savings will likely cover the cost of the technology within a short period of time.
6. Change/Clean the Filters
Perhaps the hardest working part of the entire pneumatic system, filters are constantly collecting particles that can damage the pneumatic system, its components and even the finished product. However, air filters will eventually clog and supply inadequate airflow, pressure and air quality to equipment. Checking, cleaning and replacing system filters should be a part of the preventive maintenance schedule and is likely the simplest, lowest cost way to improve airflow and gain system efficiency. At a minimum, filters should be replaced at least annually. Another option is installing filters with service indicators to aid in filter maintenance.
While it does require some time to accomplish these simple tasks and make the necessary tweaks, the energy savings and efficiency increases will make it worth the effort required to perform these low-cost suggestions. And, given the significant amount of energy consumed by a pneumatic system, it is likely that there will be a noticeable and immediate difference in the plant’s energy bill with the added bonus of better performance because the system will be closer to running in an optimized state. For more information on increasing the energy efficiency of your pneumatic system, please contact an expert at JHFOSTER.