The first step to optimizing compressed air systems within an industrial facility is to get a known baseline. To do so, utilizing a digital flowmeter is an ideal solution that will easily install onto a hard pipe that will give live readouts of the compressed air usage for the line it is installed on. There is also an additional feature that we offer on the Digital Flowmeters that can help further the understanding of the compressed air demands within a facility.
The Pressure Sensing Digital Flowmeters are available from 2″ Sched. 40 Iron Pipe up to 8″ Sched. 40 Iron Pipe. As well as 2″ to 4″ Copper pipe. These will read out and with the additional Data Logger or Wireless Capability options record the information. When coupled with the wireless capability an alarm can be set for pressure drops that give live updates on the system as well as permits data review to see trends throughout the day of the system.
Generating a pressure and consumption profile of a system can help to pinpoint energy wasters such as timer-based drains that are dumping every hour versus level based drains that only open when needed. A scenario similar to this was the cause of an entire production line shut down nearly every day of the week for a local facility until they installed flowmeters and were able to narrow the demand location down to a filter baghouse with a faulty control for the cleaning cycle.
If you would like to discuss the best digital flowmeter for your system and to better understand the benefits of pressure sensing, please contact us.
EXAIR Corporation manufactures a variety of engineered compressed air products that have been solving myriad applications in industry for almost 37 years now. In order for them to function properly, though, they have to be supplied with enough compressed air flow, which means the compressed air supply lines have to be adequately sized.
A 20 foot length of 1/4″ pipe can handle a maximum flow capacity of 18 SCFM, so it’s good for a Model 1100 Super Air Nozzle (uses 14 SCFM @80psig) or a Model 110006 6″ Super Air Knife (uses 17.4 SCFM @80psig,) but it’s going to starve anything requiring much more air than those products. Since compressed air consumption of devices like EXAIR Intelligent Compressed Air Products is directly proportional to inlet pressure, we can use the flow capacity of the pipe, the upstream air pressure, and the known consumption of the EXAIR product to calculate the inlet pressure of a starved product. This will give us an idea of its performance as well.
Let’s use a 12″ Super Air Knife, with the 20 foot length of 1/4″ pipe as an example. The ratio formula is:
(P2 ÷ P1) C1 = C2, where:
P2 – absolute pressure we’re solving for*
P1 – absolute pressure for our published compressed air consumption, or C1*
C1 – known value of compressed air consumption at supply pressure P1
C2 – compressed air consumption at supply pressure P2
*gauge pressure plus 14.7psi atmospheric pressure
This is the typical formula we use, since we’re normally solving for compressed air consumption at a certain supply pressure, but, rearranged to solve for inlet pressure assuming the consumption will be the capacity of the supply line in question:
(C2 P1) ÷ C1 = P2
[18 SCFM X (80psig + 14.7psia)] ÷ 34.8 SCFM = 49psia – 14.7psia = 34.3psig inlet pressure to the 12″ Super Air Knife.
…we can extrapolate that the performance of a 12″ Super Air Knife, supplied with a 20 foot length of 1/4″ pipe, will perform just under the parameters of one supplied at 40psig:
Air velocity less than 7,000 fpm, as compared to 11,800 fpm*
Force @6″ from target of 13.2oz total, instead of 30oz*
*Performance values for a 12″ length supplied with an adequately sized supply line, allowing for 80psig at the inlet to the Air Knife.
Qualitatively speaking, if you hold your hand in front of an adequately supplied Super Air Knife, it’ll feel an awful lot like sticking your hand out the window of a moving car at 50 miles an hour. If it’s being supplied with the 20 foot length of 1/4″ pipe, though, it’s going to feel more like a desk fan on high speed.
The type of supply line is important too. A 1/4″ pipe has an ID of about 3/8″ (0.363″, to be exact) but a 1/4″ hose has an ID of only…you guessed it…1/4″. Let’s say you have 20 feet of 1/4″ hose instead, which will handle only 7 SCFM of compressed air flow capacity:
[7 SCFM X (80psig + 14.7psia)] ÷ 34.8 SCFM = 19psia – 14.7psia = 4.3psig inlet pressure to the 12″ Super Air Knife.
Our Super Air Knife performance chart doesn’t go that low, but, qualitatively, that’s going to generate a light breeze coming out of the Super Air Knife. This is why, for good performance, it’s important to follow the recommendations in the Installation Guide:
All Installation Guides for EXAIR Intelligent Compressed Air Products contain recommended air supply line sizes for this very reason. If you have any questions, though, about proper compressed air supply, give me a call.
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The generation of compressed air accounts for approximately 1/3 of all energy costs in an industrial facility. According to the Compressed Air Challenge, about 30% of that compressed air is lost through leaks. This means nearly 10% of your facilities energy costs are simply wasted through poor connections, faulty air valves, improper installation, etc. In addition to simply wasting money, compressed air leaks can also contribute to a variety of other operating losses. A leak can cause a drop in system pressure. When this occurs, end users may not operate as efficiently and has an adverse effect on production. This same drop in system pressure will also cause the equipment to cycle on/off more often, shortening the life of your compressor and other equipment. If the leaks cause an issue in supply volume, it may lead to the belief that more compressor capacity is necessary, further increasing your operating costs.
To put leaks in perspective (assuming energy costs of .10/ kWh), the folks at Compressed Air Challenge put it this way:
A $200/year leak cannot be felt or heard
A $800/year leak can be felt, but not heard
A $1,400/year leak can be felt and heard.
If you walk through your facility, how many leaks can you hear? These are only the REALLY bad ones!! So if we know that a large amount of compressed air is leaking, what do we do about it? ? A proper leak prevention plan is the key to success. Since these leaks are impossible to see and some cannot even be heard, you need a tool to help assist you. EXAIR’s model 9061 Ultrasonic Leak Detector is the right tool for the job. When compressed air leaks through a pipe, it creates an ultrasonic signature due to turbulence. While this sound is not always detectable by the human ear, this meter will allow you to locate leaks up to 20’ away by converting the ultrasonic signature into an audible sound.
The first step will be locating the leaks using an Ultrasonic Leak Detector and tagging them throughout the facility. Don’t let this overwhelm you!! If you have a larger facility, break it up into sections that can be completed in 1 day. This will allow you to decide which areas of the plant should be looked at first. Once you’ve located and tagged all of the leaks, rate them under two separate criteria so that you can prioritize what to fix first. Rate them based on the difficulty that it will take to fix them and also by the severity of the leak. Those that are severe yet easy to fix would make sense to begin fixing first. Those that may require a period of shutdown can be planned to fix at a more appropriate time.
When you’ve had the opportunity to fix them, don’t just forget about it. When new piping is installed, new lines are added, or anything involving compressed air is installed there is the potential for new leaks to develop. Set this as one of your regular PM activities and complete your own compressed air audit once a year. Implementing the process and maintaining it are the keys to your success.
If you have questions about developing a leak program or how to use the Ultrasonic Leak Detector, give us a call. An Application Engineer will be happy to help with the process and recommend some other methods to save on your compressed air supply.
Compressed air is the life blood of a manufacturing plant, and the air compressor would be considered the heart. To keep things “fit”, it is important to check all areas and to optimize your system to keep your plant running safely and efficiently. You do not have to be a doctor to do these “operations”. If your compressor fails, the entire facility will stop working. In this blog, I will cover some simple preventative maintenance that can really help you.
As margins get tighter and cost of manufacturing climbs, industries are looking into other areas to be more economical. A big focus today is the compressed air system. Compressed air is considered to be a “forth” utility behind gas, water, and electricity, and it is a necessary to run your pneumatic systems. But it is the least efficient of the utilities. So, it is very important to use this utility as practical as possible and to use a PM program to keep it going.
If we start at the beginning of your compressed air system, this would jump us to the air compressor. This is the machine that uses an electric or gas motor to spin a crank. It compresses the ambient air into a small volume to generate stored energy to be used by your pneumatic systems. Because the air compressor is complex and intricate, I would recommend a trained service personnel to do the maintenance. But, if your staff is familiar with air compressors, I wrote a blog to help look at certain parts periodically. You can read it here: “6 Basic Steps for Good Air Compressor Maintenance (And When to Do Them)”.
The next part after the air compressor is to look at the aftercoolers, compressed air dryers, receiver tanks, filters, and condensate drains. Some facilities may only have some of these items.
The aftercoolers are designed to cool the exit air from your air compressor. It uses a fan to blow ambient air across coils to lower the compressed air temperature. It is easy to check the fan to verify that it is spinning and to keep the coils clean from debris.
The compressed air dryers can range in size and type. For the refrigerant type air dryers, you should periodically check the freon compressor with ohm and amp readings, the condensers for cleaning, and the super heat temperature as well. For desiccant type air dryers, you will need to check the operation of the valves. Valves are used to regenerate one side of the desiccant bed. The valves can fail and stick either open or closed. In either way, if the desiccant cannot regenerate, then it will allow moisture to go down stream and eventually destroy the desiccant beads.
The receiver tanks have safety relief valves that will need to be checked to make sure that they are not leaking. If they are, they should be changed.
As for the filters, they collect contamination from the compressed air stream. This will include liquid water, oil, and dirt. A pressure drop will start to increase with the contaminants, which will reduce the potential energy. If they do not have pressure drop indicators, you should have two points of references for pressure readings. You should change the filter elements when the pressure drop reaches 10 PSID (0.7 bar) or after 1 year.
With all these items above, water is created. There should be condensate drains to discard the water. The most efficient types of condensate drains are the zero loss drains. Most condensate drains will have a test button to be pressed to verify that they open. If they do not open, they should be replaced or fixed. Do not place a valve on them and partially open for draining. For float type drains, they will have a pin inside that can be pressed to open. You can verify that all the liquid has been expelled.
The distribution system are the pipes and tubes that run compressed air from the supply side to the demand side of your pneumatic system. One of the largest problems affecting the distribution system are leaks. That quiet little hissing sound from the pipe lines is costing your company much money. A study was conducted by a university to determine the percentage of air leaks in a typical manufacturing plant. In a poorly maintained system, they found on average of 30% of the compressor capacity is lost through air leaks.
To put a dollar value on it, a leak that you cannot physically hear can cost you as much as $130/year. That is just for one inaudible leak in hundreds of feet of compressed air lines. Unlike a hydraulic system, compressed air is clean; so, leaks will not appear at the source. So, you have to find them by some other means.
Most leaks occur where you have threaded fittings, connections, hoses, and pneumatic components like valves, regulators, and drains. EXAIR has two products in our Optimization product line that are designed to help find leaks in your compressed air system.
The Ultrasonic Leak Detectors can find air leaks, and the Digital Flowmeters can monitor your system for loss of air. When an air leaks occur, it emits an ultrasonic noise caused by turbulence. These ultrasonic noises can be at a frequency above audible hearing for human. The EXAIR Ultrasonic Leak Detector can pick up these high frequencies to make inaudible leaks audible.
With the Digital Flowmeters, you can continuously check your system for waste and record it with a USB Datalogger. Air leaks can occur at any time within any section of your pneumatic system. With a Digital Flowmeter, you can also isolate an area to watch for any flow readings; telling you that the air is leaking in that section. With both products included in your leak-preventative program, you will be able to reduce your waste and optimize your compressed air system.
At the point-of-use areas, this is the easiest target area for compressed air maintenance. If you are using open tubes or drilled pipes for blowing, they are loud, inefficient, and unsafe. They can be easily change to an engineered blow-off product from EXAIR which are very efficient and OSHA safe. EXAIR offers a range of Super Air Nozzles and Super Air Knives to simply replace the current blow-off devices that overuse compressed air. If we go back to the beginning of your system, the air compressor is a mechanical device which will have a MTBF, or Mean Time Between Failures. The hour meter on your air compressor is like a life monitor. By using less compressed air, your air compressor will extend that time in MTBF.
Keeping your compressed air system running optimally is very important for a business to run. With a simple maintenance program, it can help you with your pneumatic operations and energy savings. Like stated above, your compressed air system is the life blood of your company, and you do not need a PhD to keep it well maintained. Just follow the target areas above. If you would like to discuss further about the health of your compressed air system, you can contact an Application Engineer at EXAIR. We will be happy to help “diagnose” a solution.