Even casual readers of the EXAIR Blog will notice that we Application Engineers are keen on efficiency. I just counted sixty-seven blogs on the site that discuss our Six Steps To Optimizing Your Compressed Air System. Some offer a broad overview, while others focus on specific steps, and one tells us more than I ever expected to learn from an engineering blog about…Bigfoot.
I’m going to take a different tack here – no; I’m not going to write about the Yeti or the Loch Ness Monster, but I may try to get the Jersey Devil into a blog someday. I will, instead, relate some real-life examples of the success of implementing each individual step. It’s important to note here that they don’t have to be done in order, or even in total, to achieve impressive results.
- Measure the air consumption to find sources that use a lot of compressed air. Like I just said, you don’t HAVE to do these steps in order, but if you DO intend to pursue a comprehensive solution, this is where you want to start. The facility manager of a large manufacturing plant did just that when a series of Digital Flowmeters were installed in the branch lines to their production cells. By comparing their present-day actual usage to the original design specifications, they noticed that usage in a certain cell (due to business growth) had increased to the point that they had raised the main header pressure in an attempt to keep point-of-use pressures at proper levels. By installing a larger diameter branch line to that cell, they were able to reduce main header pressure from 120psig to 100psig, reducing their compressors’ energy usage (and their share of the electric bill) by 10%.
- Find and fix the leaks in your compressed air system. A factory once noticed they were losing header pressure overnight, when they were closed. Using an Ultrasonic Leak Detector, they identified some small leaks that nobody thought were all that significant…until they did the math, comparing previous compressed air consumption (including those leaks) to that of their “new and improved” leak-free system. Fixing those leaks saved them just over a million cubic feet of compressed air a year. The exact figure was 1,062,500 cubic feet, annually. I know this is accurate, because it was us.
- Upgrade your blowoff, cooling and drying operations using engineered compressed air products. This could apply to almost every single order we process, so I’m going use an example from my first day here. During training, I learned that a customer had recently called to get air consumption data on some EXAIR products they were going to implement as part of an upgrade that was also going to involve purchasing a new compressor. Their main usage was a number of open-end blow offs that ran continuously. After outfitting those with Model 1100 Super Air Nozzles and Model 9040 Foot Pedals (so the operators had simple, hands-free control over blowing cycles), they not only found they didn’t need a new air compressor, but were able to shut down an existing 50HP air compressor.
- Turn off the compressed air when it isn’t in use. There are a few methods for doing this, and they’re all pretty easy:
- Good. Manual shutoff valves (1/4 turn ball valves are great for this) can be used by mindful operators to shut off compressed air use between production cycles, during lunch breaks, and (I hope this is patently obvious to the most casual observer) at closing time. I’ve talked to users about doing this, but I don’t have any great success stories about this method. It relies on someone’s memory in knowing when to operate the valve…and nobody’s remembered to call me back with a full report either.
- Better. If you only need air blowing while a machine is running,
most any qualified industrial electrician can wire a solenoid valve into the on/off control of the machine. Better yet, if the system has programmable logic control (PLC), it can be used to open & shut that same solenoid valve, to effect blow off only as needed. I worked with an automotive parts manufacturer who had a robot passing parts between a pair of Model 110042 42″ Aluminum Super Air Knives. They had taken care to accurately position the Air Knives, and program the robot’s movement & speed, to optimize blow off…but the Air Knives were running continuously. After a brief conversation with the line foreman, they bought and installed a Model 9065 1 NPT 24VDC Solenoid Valve and “told” the PLC to turn air flow on as the robotic arm approached the Air Knives, and turn it off right after the part had passed through.
- Best. In the absence of programmable logic, the simplicity of the EXAIR EFC Electronic Flow Control just can’t be beat. It’s a standalone system that consists of a Solenoid Valve that’s operated by a photoelectric sensor and controlled by a programmable timer. Whether it’s a tenth of a second, or a few minutes, waste is waste, and it adds up. Consider this application writeup from our Optimization Products catalog section:
- Use intermediate storage of compressed air near the point of use. If
compressed air is used in any sizable amount in your facility, odds are, you have a compressor room. If it’s done right, this is a good thing for your compressor, but it CAN present some challenges for distribution over large areas. A user of EXAIR Super Ion Air Knives, for example, installed a Model 9500-60 Receiver Tank in an area some distance from the compressor room to maintain higher air pressure than line loss (from the length of the header pipe) was allowing. Their other option was to increase their overall header pressure; this allowed them to maintain current costs…increasing system pressure by 2psi equates to a 1% increase in compressed air generation costs.
- Control the air pressure at the point of use to minimize air consumption. In addition to controlling OVERALL compressed air system pressure (see examples 1 & 5 above), using Pressure Regulators to control the supply pressure to specific compressed air operated products will save you money too…the lower the supply pressure, the lower the consumption. A Model 1101 1/4 MNPT Super Air Nozzle, for example, uses 14 SCFM when supplied at 80psig…that’s where we publish its performance, because that’ll give a good, strong blast of air, suitable for a wide range of typical industrial air blowing applications. A tube manufacturer once replaced two open blow off devices that used about 38 SCFM each with Model 1101’s. Even though that cut their air consumption by more than half, they were able to cut it even further by regulating the supply pressure to 56psig…that’s the pressure at which they could still get the job done consistently, resulting in ANOTHER 25% reduction in compressed air consumption.
If you’d like to find out more about any, or all, of the Six Steps To Optimizing Your Compressed Air System, give me a call.
Russ Bowman, CCASS