EXAIR’s Atomizing Spray Nozzles are used to atomize fluids in a wide range of different spray patterns. They utilize a small amount of compressed air which mixes with the liquid supply to create a fine… More
At EXAIR we’ve been providing enclosure cooling solutions for decades, and in many cases those cooling solutions have remained in place for decades as well. In the time we’ve been in the market with industrial enclosure cooling solutions we’ve encountered a number of alternative means for enclosure cooling. One of those methods is an air-to-air heat exchanger.
An air-to-air heat exchanger uses the temperature differential between the ambient air surrounding an enclosure and the hot air inside an enclosure to create a cooling effect. A closed loop system exchanges the heat inside the enclosure with the outside air in an effort to maintain a set internal temperature. The heat exchange of most air-to-air unit relies on a heat pipe, a heat-transfer device which converts an internal refrigerant liquid into vapor by placing one end of the pipe in contact with the hot environment. The heated vapor travels to the other end of the pipe which is in contact with a cooler environment. The vapor condenses back into a liquid (releasing latent heat) and returning to the hot end of the pipe and the cycle repeats.
But, this type of a solution does give some cause for concern, especially when considering their use in an industrial environment. Here are the key points to keep in mind when comparing an air-to-air cooler to an EXAIR Cabinet Cooler.
Required temperature differential based on ambient air temp
An air-to-air heat exchange relies on the ΔT between the ambient air temperature and the internal enclosure air temperature to produce cooling. If this ΔT is low, or the ambient temperature rises, cooling is diminished. This means that as the temperatures in your facility begin to rise, air-to-air heat exchangers become less and less effective. Larger air-to-air heat exchangers can be used, but these may be even larger than the enclosure itself.
EXAIR Cabinet Coolers rely on the ΔT between the cold air temperature from the Cabinet Cooler (normally ~20°F) and the desired internal enclosure temperature (normally 95°F). The cold air temperature from the Cabinet Cooler is unaffected by increases in ambient temperatures. The large ΔT and high volume cold air flow produced by a Cabinet Cooler results in more cooling capacity. And, we can increase cooling capacity from a Cabinet Cooler without increasing its physical footprint, which is already much, much smaller than an air-to-air type of unit.
Cooling in high temperature environments
Due to their nature of operation, an air-to-air heat exchanger must have an ambient temperature which is lower than the desired internal temperature of the enclosure. If the ambient air has a higher temperature, air-to-air units provide zero cooling.
Cabinet Coolers, on the other hand, can be used in hot, high temperature environments up to 200°F (93°C).
Cooling in dirty environments
Dirt in the ambient environment will impact cooling performance with an air-to-air heat exchanger. In order for the air-to-air unit to effectively remove heat, the heat pipe must have access to ambient air. With any exposure to the ambient environment comes the possibility for the ambient end of the heat pipe to become covered in ambient contaminants such as dust. This dust will create an insulation barrier between the heat pipe and the ambient air, decreasing the ability for the heat pipe to condense the vapors within. Because of this, most air-to-air devices use filters to separate the heat pipe from the ambient environment. But, when these filters become clogged, access to ambient temperatures are reduced, and cooling capacity of the air-to-air unit reduces as well.
Cabinet Coolers have no problem operating in dirty environments. In fact, it is one of their strengths. Without any moving parts to wear out or any need to contact ambient air for cooling purposes, a dirty environment poses no problems. In fact, check out this blog post (and this one) about EXAIR Cabinet Coolers operating maintenance free for years in dirty environments.
Size and time required to install
Air-to-air heat exchangers vary in size, but even the smallest units can have large dimensions. Many applications have limited space on the enclosure, and a large, bulky solution can be prohibitive. Couple this with the time and modification required to the enclosure to install a large air-to-air unit, and the “solution” may end up bringing additional problems.
Another key aspect of the Cabinet Cooler is its size. Small, compact, and easy to mount on the top or side of an enclosure, Cabinet Coolers install in minutes to remove overheating problems.
Heat within an electrical cabinet can be a major issue for manufacturing companies. The costs associated with down time and repairs on sensitive electronics that fail due to heat or environmental contaminants, are an unnecessary burden. If you have any questions about how an EXAIR Cabinet Cooler can solve problems in your facility, contact an EXAIR Application Engineer.
My colleague, Lee Evans, wrote a blog about calculating the size of primary receiver tanks within a compressed air system. (You can read it here: Receiver Tank Principle and Calculations). I would like to expand a bit more about secondary receiver tanks. They can be strategically placed throughout the plant to improve your compressed air system. The primary receiver tanks help to protect the supply side when demands are high, and the secondary receiver tanks help systems on the demand side to optimize performance.
I like to compare the pneumatic system to an electrical system. The receiver tanks are like capacitors. They store energy produced by an air compressor like a capacitor stores energy from an electrical source. If you have ever seen an electrical circuit board, you notice many capacitors with different sizes throughout the circuit board (reference photo above). The reason is to have a ready source of energy to increase efficiency and speed for the ebbs and flows of electrical signals. The same can be said for the secondary receiver tanks in a pneumatic system.
To tie this to a compressed air system, if you have an area that requires a high volume of compressed air intermittently, a secondary receiver tank would benefit this system. There are valves, cylinders, actuators, and pneumatic controls which turn on and off. And in most situations, very quickly. To maximize speed and efficiency, it is important to have a ready source of air nearby to supply the necessary amount quickly.
For calculating a minimum volume size for your secondary receiver tank, we can use Equation 1 below. It is the same as sizing a primary receiver tank, but the scalars are slightly different. The secondary receivers are located to run a certain machine or area. The supply line to this tank will typically come from a header pipe that supplies the entire facility. Generally, it is smaller in diameter; so, we have to look at the air supply that it can feed into the tank. For example, a 1” NPT Schedule 40 Pipe at 100 PSIG can supply a maximum of 150 SCFM of air flow. This value is used for Cap below. C is the largest air demand for the machine or targeted area that will be using the tank. If the C value is less than the Cap value, then a secondary tank is not needed. If the Cap is below the C value, then we can calculate the smallest volume that would be needed. The other value is the minimum tank pressure. In most cases, a regulator is used to set the air pressure for the machine or area. If the specification is 80 PSIG, then you would use this value as P2. P1 is the header pressure that will be coming into the secondary tank. With this collection of information, you can use Equation 1 to calculate the minimum tank volume. So, any larger volume would fit the requirement as a secondary receiver tank.
Secondary Receiver tank capacity formula (Equation 1)
V = T * (C – Cap) * (Pa) / (P1-P2)
V – Volume of receiver tank (cubic feet)
T – Time interval (minutes)
C – Air demand for system (cubic feet per minute)
Cap – Supply value of inlet pipe (cubic feet per minute)
Pa – Absolute atmospheric pressure (PSIA)
P1 – Header Pressure (PSIG)
P2 – Regulated Pressure (PSIG)
If you find that your pneumatic devices are lacking in performance because the air pressure seems to drop during operation, you may need to add a secondary receiver to that system. For any intermittent design, the tank can store that energy like a capacitor to optimize the performance. EXAIR stocks 60 Gallon tanks, model 9500-60 to add to those specific locations, If you have any questions about using a receiver tank in your application, primary or secondary, you can contact an EXAIR Application Engineer. We can restore that efficiency and speed back into your application.
On a recent visit with our Hungarian Distributor, I had the pleasure of visiting an automotive leather manufacturing plant. They process and cut to order a wide variety of different styles of leather used in the manufacturing of European automobiles. In one of their machines, a grinding process is performed that smooths out the cut edges of the material before they’re stitched together.
The grinding process itself is self-contained within the machine, but the significant amount of leather dust created needs to be periodically cleaned out. If not, it ends up accumulating on some of the internal components and increasing the downtime and maintenance required on the machine. Due to this, they implemented a 2x per shift cleaning operation.
The machine has several tight spaces inside where the dust accumulates. They’d shut off the machine and blow out the dust. Then, sweep up all of the dust into a dustpan and dump it in the trash. This entire process took approximately 30 minutes each time for 1-hr/shift. With three shifts operating 24/7, that’s 3-hrs/day of lost production time for this particular cleaning process, still less than what they were experiencing as a result of the machine downtime when they weren’t regularly cleaning it.
However, the primary concern of theirs was that they were now blowing dust all over the shop causing a potential health hazard to their operators. They wanted a solution that would allow them to clean the machine, without presenting an additional hazard. We tested with a Mini Chip Vac first, but the dust was a bit too fine and was still passing through the filter bag.
For fine dusts such as this, the Heavy Duty HEPA Vac is the more suitable option. After testing the Heavy Duty HEPA Vac, it was clear that this was the solution they were hoping for. The high-powered vacuum made quick work of the dust inside, while keeping it contained inside of the drum by the HEPA filter.
They still need to stop and clean the machine out 2x/shift, but now the process only took 10 minutes. They reduced their overall downtime on this machine per day by 2/3 to just 1hr, while keeping their operators safe. While this wasn’t the reason for looking at new solutions, it was definitely an added benefit. If you’re looking for a maintenance-free vacuum system for cleaning up in your facility, EXAIR has a wide range of Industrial Housekeeping solutions available from stock.
If you’re a regular reader of the EXAIR blog, you’re likely familiar with our:
This guideline is as comprehensive as you want it to be. It’s been applied, in small & large facilities, as the framework for a formal set of procedures, followed in order, with the goal of large scale reductions in the costs associated with the operation of compressed air systems…and it works like a charm. Others have “stepped” in and out, knowing already where some of their larger problems were – if you can actually hear or see evidence of leaks, your first step doesn’t necessarily have to be the installation of a Digital Flowmeter.
Here are some ways you may be able to “step” in and out to realize opportunities for savings on your use of compressed air:
- Power: I’m not saying you need to run out & buy a new compressor, but if yours is
aging, requires more frequent maintenance, doesn’t have any particular energy efficiency ratings, etc…you might need to run out & buy a new compressor. Or at least consult with a reputable air compressor dealer about power consumption. You might not need to replace the whole compressor system if it can be retrofitted with more efficient controls.
- Pressure: Not every use of your compressed air requires full header pressure. In fact, sometimes it’s downright detrimental for the pressure to be too high. Depending on the layout of your compressed air supply lines, your header pressure may be set a little higher than the load with the highest required pressure, and that’s OK. If it’s significantly higher, intermediate storage (like EXAIR’s Model 9500-60 Receiver Tank, shown on the right) may be worth looking into. Keep in mind, every 2psi increase in your header pressure means a 1% increase (approximately) in electric cost for your compressor operation. Higher than needed pressures also increase wear and tear on pneumatic tools, and increase the chances of leaks developing.
- Consumption: Much like newer technologies in compressor design contribute to higher efficiency & lower electric power consumption, engineered compressed air products will use much less air than other methods. A 1/4″ copper tube is more than capable of blowing chips & debris away from a machine tool chuck, but it’s going to use as much as 33 SCFM. A Model 1100 Super Air Nozzle (shown on the right) can do the same job and use only 14 SCFM. This one was installed directly on to the end of the copper tube, quickly and easily, with a compression fitting.
- Leaks: These are part of your consumption, whether you like it or not. And you shouldn’t like it, because they’re not doing anything for you, AND they’re costing you money. Fix all the leaks you can…and you can fix them all. Our Model 9061 Ultrasonic Leak Detector (right) can be critical to your efforts in finding these leaks, wherever they may be.
- Pressure, part 2: Not every use of your compressed air requires full header pressure (seems I’ve heard that before?) Controlling the pressure required for individual applications, at the point of use, keeps your header pressure where it needs to be. All EXAIR Intelligent Compressed Air Product Kits come with a Pressure Regulator (like the one shown on the right) for this exact purpose.
Air Quality: Dirty air isn’t good for anything. It’ll clog (and eventually foul) the inner workings of pneumatic valves, motors, and cylinders. It’s particularly detrimental to the operation of engineered compressed air products…it can obstruct the flow of Air Knives & Air Nozzles, hamper the cooling capacity of Vortex Tubes & Spot Cooling Products, and limit the vacuum (& vacuum flow) capacity of Vacuum Generators, Line Vacs, and Air Amplifiers.
Everyone here at EXAIR Corporation wants you to get the most out of your compressed air use. If you’d like to find out more, give me a call.
On our Website we have a comprehensive database of applications we have worked on with our products. These are pretty easy to find, Johns Blog will walk you through the process on how to access these applications. While John covered Compressed Air Use in the Construction Industry, I will be covering Compressed Air Use in Food and Beverage Industry.
EXAIR products are very commonly used in the food and beverage industry, from blowing water off cans before labeling, to conveying food products to hoppers for processing. See three examples from our application data base;
Use our Application Assistance Worksheet to submit information about your application. When you submit this information, we will respond with our recommendation for the EXAIR product best suited for the application. Please complete the Application Assistance Worksheet and click submit or print the completed .pdf file and fax it to us at (513) 671-3363. For immediate help, call our Application Engineering Department at 1 800 903-9247.
Just last night I was in my garage tinkering around with a vintage Coleman Camping lantern from 1949 that I am working on refurbishing. I grabbed my parts washing bin (A bread pan my wife let me have because she didn’t like the way it cooked bread) and was reminded that I had been soaking a helmet lock from a friends dirt bike in a penetrating oil. I removed the lock from the pan, wiped it down, then went to my trusty 30 gallon compressor to use a Safety Air Gun to blow the residual oil out of the lock.
When not in use my compressor stays turned off and I modified the factory outlet to include a quarter turn ball valve so that I can retain all air in the receiver tank and not have to charge the tank up every time that I use it. As I turned the valve on I was reminded that I have a rather large air leak that can drain the 30 gallon tank down from 150 psig to 60 psig within a few hours.
While my air system is almost as simple as it can be, single air hose real with an additional quick disconnect before the hose reel for small quick blow offs, it still has over a dozen connections within the system. While my worst offending leak is audible to my slightly aged ears there are other leaks that I cannot see or hear. That is unless I use one of two methods I know to find leaks.
The easiest is right out of our 6 Steps of Compressed Air Optimization, the Ultrasonic Leak Detector (ULD). The ULD is a versatile, low cost, hands free electronic device that will quickly and easily detect the general vicinity of a leak and then easily pinpoint the exact point of the leak. In conducting a test, it took right at twenty minutes to test each of the connections within my system and identify which connections had leaks. The actual repairs of the leaks around an hour. Before fixing though I timed the amount of time it took a friend to use the soapy water method to detect the same leaks.
The soapy water method timed in at around thirty-five minutes for the same number of connections. This was due to a few of the fittings needing to be tested multiple times because of small leaks. It then took an additional fifteen minutes to wipe up all the soapy water that was now dripping down the air line and around the fittings.
While both methods found the same leaks and the ULD performed the task quicker and without any cleanup required, the true focus was on all leaks being repaired. My system has a dozen connection points for a two outlet compressed air system that are regulated and filtered at a single point. This system was draining a 30 gallon tank within a few hours which costs me every time I used my compressor and did not shut off the valve that shuts off the system.
This burden on my electrical bill was removed with less than two hours of labor and I can now leave the compressor fully charged and have air as soon as I need it rather than having to wait for the tank to charge up. Had this been in a production environment the cost could have crippled production resulting in catastrophic.
If you would like to discuss how leaks within your system can easily be found by using the ULD or would like to learn more about the other five steps in our Six Steps To Compressed Air Optimization, contact an Application Engineer.
Return on Investment, or ROI, is the ratio of profit over total investment. Many people use it to check stocks, financial markets, capital equipment, etc. It is a quantitative way in determining the validity for an investment or project. You can use the ROI value to give a measurable rate in looking at your investment.
For a positive ROI value, the project will pay for itself in less than one year. Any negative values would represent a high-risk investment. In this blog, I will compare the ROI when replacing a ¼” NPT open pipe with a model 1122 2” Flat Super Air Nozzle. Let’s start by looking at Equation 1 to calculate the Return on Investment:
Equation 1: ROI = (Total annual savings – Total Project Cost) / Total Project Cost * 100
The second part of the equation, Total Project Cost, is the cost of the nozzles plus the labor to install them onto the machine. The model 1122, 2” Flat Super Air Nozzle, has a price of $70.00 each. The cost of a ¼” NPT Pipe that is roughly 2” long is around $1.50 each. What a difference! How could EXAIR been in business for over 35 years? Let’s continue on with the Return on Investment…
The amount of time required to install the nozzles to the end of a pipe is 1/2 hour (generously). The labor rate that I will use in this example is $75.00 per hour (you can change this to your current labor rate). The labor cost to install a nozzle is $35.00. The Total Project Cost can be calculated as follows: ($70 – $1.50) + $35.00 = $103.50. The next part of the equation, Total annual savings, has more complexity in the calculation, as shown below.
As a reference, EXAIR Super Air Nozzles for compressed air would be considered like LED light bulbs for electricity. The open pipes and tubes would represent the incandescent light bulbs. The reason for this parity is because of the amount of energy that the EXAIR Super Air Nozzles can save. While LED light bulbs are a bit more expensive than the incandescent light bulbs, the Return on Investment has a high percentage, or in other words, a short payback period. On the other hand, the open pipe is less expensive to purchase, but the overall cost to use in your compressed air system is much much higher. I will explain why.
To calculate the Total Annual Savings, we need to generate a blow-off scenario (You can use your actual values to calculate the ROI for your project). In this example, I will compare the ¼” NPT open pipe to the 2” Flat Super Air Nozzle. (The reason behind this comparison is that the model 1122 can screw directly onto the end of the 1/4” NPT pipe.) The amount of compressed air used by a 1/4” NPT open pipe is around 140 SCFM (3,962 SLPM) at 80 PSIG (5.5 Bar). The model 1122 has an air consumption of 21.8 SCFM (622 SLPM) at 80 PSIG (5.5 Bar). At an electrical rate of $0.08 per Kilowatt-hour, we see that the cost to make compressed air is $0.25 per 1000 standard cubic feet, or $0.25/1000SCF. (Based on 4 SCFM per horsepower of air compressor).
To calculate an annual savings, let’s use a blow-off operation of 8 hours/day for 250 days a year. Replacing the ¼” NPT open pipe with a model 1122, it will save you (140 SCFM – 21.8 SCFM) = 118.2 SCFM of compressed air. To put this into a monetary value, the annual savings will be 118.2 SCFM *$0.25/1000SCF * 60 Min/hr * 8hr/day * 250 day/yr = $3,546/year. Now if you have more than one blow-off spot in your facility like this, imagine the total amount of money that you would save.
With the Total Annual Cost and the Project Cost known, we can insert these values into Equation 1 to calculate the ROI:
ROI = (Total annual savings – Total Project Cost) / Project Cost * 100
ROI = ($3,546 – $103.50) / $103.50 * 100
ROI = 3326%
With a percentage value that high, we are looking at a payback period of only 9 days. You may look at the initial cost and be discouraged. But in a little over a week, the model 1122 will have paid for itself. And after using it for just 1 year, it will save your company $3,546.00. Like with any great idea, the LED light bulb clicked on in my mind. What could be the total savings if you looked at all the blow-off applications in your facility?
In my experience, a loud blowing noise from your equipment is generally coming from an open pipe or tube. With these “cheap” ways to blow compressed air, it will cost your company a lot of money to use as shown in the example above. If you would like to team up with EXAIR to set up ways to increase savings, improve productivity, and increase safety, you can contact an Application Engineer to get started. It can be as simple as screwing on a Super Air Nozzle.