Any time you’re considering a new purchase your return on investment is a critical aspect of the decision-making process. A recent case for me this past year was the purchase of a new riding lawn mower. What used to take me 2-hours to mow my entire yard, now only takes 45 minutes. Mowing 1 time per week throughout the growing season, I was able to save over an hour of my time each week! Considering that I’ll mow the lawn approximately 25 times per year, that’s more than a full day’s worth of time saved over the course of a year.
Some products, however, provide a monetary value due to reduced operating costs. For example, an LED light bulb may cost more initially but will use less energy to operate as well as have a longer lifespan than an incandescent bulb. You can calculate, down to the day, when you’ll recoup the costs difference from buying the more expensive bulb.
The same can be said for EXAIR’s Intelligent Compressed Air Products. An extrusion company had a line where they were using (3) modular-hose style flat nozzles. (1) was placed just before a water bath to remove some of the initial heat, (2) were then placed as the material exited the bath to dry the material after it was cooled. While they did work, they had begun to notice pressure drops in their compressed air system that was causing issues for other processes in the facility.
The (3) nozzles were all operated at 50 PSIG consuming 17 SCFM per nozzle for a total consumption of 51 SCFM. They were operated for one full 8-hour shift, 5 days per week.
51 SCFM x 60 mins x 8-hours = 24,480 SCF/day
Since they had a range of different sizes of material they process with the widest up to 2.5”, we recommended replacing the modular style hose flat nozzles with EXAIR’s 3” Super Air Knife. At a pressure of 50 PSIG, (3) Model 110003 Super Air Knives consumes just 17.1 SCFM.
17.1 SCFM x 60 mins x 8-hours = 8,208 SCF/day
By implementing the Super Air Knife, they reduced their compressed air consumption for this particular application by 66.4%!! But, just how quickly will that air savings provide them with a return on their investment? Let’s calculate the savings:
The average cost for compressed air is $0.25/1000 SCF. Before the installation of the Super Air Knives, the total consumption was 24,480 SCF/day.
24,480 SCF x $0.25/1000 SCF = $6.12/ day
With the Super Air Knives, this was reduced to just 8,208 SCF/ day:
8,208 SCF x $0.25/1000 SCF = $2.05/ day
Total Savings – $4.07 each day!!!
The 2019 list price on the Model 110003 is $206.00. Since they bought (3) their total investment was $618.00.
$618.00/$4.07 = 151.84 (152 days)
On the 152nd day, the customer will have saved enough money from the reduced air consumption to account for the initial purchase price of the Super Air Knives. Once they’re paid for, it isn’t like you just stop saving money. These knives will continue to save money, each shift, day in and day out. If there’s a process in your facility that you can improve upon, give us a call. We’re also able to test it out here at EXAIR and report back to you on the savings through our free Efficiency Lab!
The cheapest and easiest solution isn’t always necessarily the best. The best example I like to use to highlight this is the incandescent light bulb. They’re definitely the cheapest to buy, but over the useful life it will cost more in electricity to operate and it won’t last nearly as long as an LED light bulb. When you compare the costs of electricity as well as the lifespan of an incandescent bulb, it becomes quite clear that the initial price difference between the two will be quickly recouped over the lifetime of the LED bulb. Once it pays for itself, it doesn’t just stop saving you electricity. These savings continue to compound.
The same can be said when comparing the Super Air Knife to a commonly seen homemade alternative, drilled pipe. While it only takes a matter of minutes to drill a few holes into a section of pipe, the operating costs (electricity required to generate the compressed air) are significantly higher than that of the Super Air Knife. In addition, it’s not nearly as effective and is considered unsafe under OSHA 29 CFR 1910.242 (b) and depending on operating pressure is likely also considered dangerous due to the high sound levels as outlined in OSHA 29 CFR 1910.95(a).
Air exiting out of drilled holes in a pipe will create a turbulent airstream. This turbulence not only contributes to the high sound level but it’s ability to entrain surrounding ambient air is minuscule. The air entrainment ratio of a compressed air solution refers to the relationship between supplied compressed air and the free ambient air that is brought into the primary airstream. The higher the amplification ratio, the less compressed air necessary to complete a similar task. For a drilled pipe, the amplification ratio is generally around 3:1. With the Super Air Knife, this is dramatically increased with an amplification ratio of 40:1.
The Super Air Knife has a precisely set air gap across the full length of the knife, allowing for an efficient and quiet laminar airstream. When compared to a drilled pipe, the air consumption is dramatically reduced as is the sound level. For example, let’s take an 18” section of drilled pipe, with 1/16” diameter holes spaced out every ½”. At 80 PSIG, each hole consumes 3.8 SCFM. With a total of 37 holes, this equates to a total of 140.6 SCFM.
3.8 SCFM x 37 = 140.6 SCFM
A Super Air Knife, operated at 80 PSIG with .002” stock shim installed will consume a total of 2.9 SCFM per inch of knife. An 18” SAK would then consume just 52.2 SCFM.
2.9 SCFM x 18 = 52.2 SCFM
140.6 SCFM – 52.2 SCFM = 88.4 SCFM saved
Replacing an 18” drilled pipe with a Super Air Knife represents a total reduction in compressed air consumption of 63%! How much does this equate to in $$$? A reasonable average of cost to generate compressed air is about $0.25/ 1000 SCF. Let’s assume just a 40hr workweek:
88.4 SCFM x 60 mins x $0.25/1000 SCF = $1.33/hr
$1.33 x 40hr workweek = $53.20 USD
$53.20 x 52 weeks/year = $2,766.40 USD in yearly savings
The 2019 list price on a Model 110018 Super Air Knife is $397.00. By replacing the homemade solution with an 18” Super Air Knife, the return on investment is just over 38 working days of an 8-hr shift. If your plant runs multiple shifts, or works on weekends, it pays for itself even quicker.
Once the knife has paid for itself, it doesn’t just simply stop saving you money. That savings continues to compound and add to your bottom line. Don’t waste unnecessary air (and money) by using solutions that aren’t engineered to do the job in a safe and efficient manner. Reach out to an Application Engineer and get yourself an Intelligent Compressed Air Product that’s Built to Last.
In 1983, EXAIR Corporation was founded with the goal of engineering & manufacturing quiet, safe, and efficient compressed air products for industry. By 1988, the EXAIR-Knife (now known as the Standard Air Knife) was quickly becoming the preferred choice for replacing loud and inefficient drilled pipes, long nozzle manifolds…anywhere an even, high velocity curtain of air was required.
The EXAIR Standard Air Knife’s design takes advantage of a fascinating principle of fluidics to achieve quiet and efficient operation: the Coanda Effect, which is the tendency of a fluid jet to stay attached to a convex surface. If you want to see it for yourself, hold the back of a spoon, handle up, under the kitchen faucet. Those who haven’t seen it before may assume that gravity will take over and the water will fall from the bottom of the spoon’s ‘bowl’ – but it doesn’t:
Likewise, the air flow (which is just another example of a fluid jet) exiting the Standard Air Knife’s shim gap follows a convex surface (which we call the “Coanda profile”) causing it to entrain large amounts of air from the surrounding environment:
This entrainment does two things for us:
First, because we’ve engineered the design for maximum entrainment, it’s very efficient – creating a high flow rate, while minimizing air consumption. In the case of the Standard Air Knife, the entrainment ratio is 30:1.
Secondly, this entrainment forms an attenuating boundary layer for the air flow, resulting in a high velocity, high volume airflow that is also incredibly quiet.
If you need a hard hitting curtain of air for blow off, drying, cleaning, cooling, environmental separation, etc., the EXAIR Standard Air Knife is an easy and economical solution. If you’d like to discuss your application and/or product selection, give me a call.
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EXAIR has been manufacturing Intelligent Compressed Air® products since 1983. In the beginning, the Standard Air Knives and Full Flow Air Knives were very effective at that time. But as leaders in this market, EXAIR did not want to stop there. We were able to engineer a more efficient, more powerful, and much safer air knife, the Super Air Knife. In this blog, I will discuss the features and benefits that the Super Air Knives can offer.
Bernoulli’s principle explains how a high velocity fluid can generate a low pressure. The EXAIR Super Air Knife creates a high velocity air stream to produce a low pressure to entrain ambient air. What does this mean for you? It will save you much money by using less compressed air. The mass of the ambient air is added into the air stream to give a strong blowing force. The Super Air Knife has an amplification ratio of 40:1. For every 1 part of compressed air, 40 parts of ambient air is drawn into the blowing air stream. Ambient air is free, and compressed air is expensive. EXAIR was able to engineer a design to use the Bernoulli’s principle to make one of the most efficient air knives in the market place.
What else makes EXAIR unchallenged? We manufacture and stock the widest range in lengths and materials. To start, EXAIR has Super Air Knives ranging from 3” to 108” (76mm to 2,743mm) in three different materials; aluminum, 303 stainless steel, and 316/316L stainless steel. There is no-one else in this industry that can manufacture to those lengths. EXAIR also offers Super Air Knives in PVDF material with Hastelloy hardware for chemical resistant applications from 3” to 54” (76mm to 1,372mm). Depending on the temperature requirement, chemical resistance, OSHA and FDA regulations, or application details, we probably will have one on the shelf for you. If EXAIR does not have it, we can make special air knives in different lengths and materials to best fit your application.
Some interesting features for the Super Air Knives are as follows. They have a compact design that can fit into tight places for blowing and cooling. The footprint is very small compared to blower-air knife system. They do not have any moving parts to wear or maintenance to do. They only need clean compressed air to work. They blow a laminar air stream which reduces noise levels and create a consistent force along the entire length. An even force will give you tighter control for blowing applications which will cut compressed air usage unlike the inconsistent and turbulent air flows caused by drilled pipes.
To adjust the force and air usage, this can be easily controlled with a regulator. The advantage that EXAIR Super Air Knives have is the replaceable shims. So, you can increase or decrease the gap to get a variety of force ratings. The Aluminum version uses colored plastic shims for visual verification. They come stock with a 0.002” (0.05mm) red shim installed. We have other thicknesses in our Shim Sets which includes a 0.001” (0.03mm), 0.003” (0.08mm), and a 0.004” (0.10mm) colored as amber, green, and tan respectively. The Stainless Steel Super Air Knives come with a stainless steel shim for higher temperatures and chemical resistance. Stock units have the 0.002” (0.05mm) thickness as well. The Shim Sets come with three additional 0.002” (0.05mm) shims to stack. Similarly, the PVDF Super Air Knives use a PTFE shim for maximum chemical resistance. It is also 0.002” (0.05mm) thick, and there are three more shims in the Shim Set. This unique feature of using shims allows for the most flexibility in creating forces for different applications ranging from a blast to remove rocks from a conveyor to a breeze for light duty work.
We also offer the Super Air Knives in kits as a more complete system. The kit includes a filter, regulator and the above-mentioned Shim Set. The filter removes the debris and water from the compressed air line to optimize the performance of the air knife as well as keeping your product clean. The regulator is used to make the “fine” adjustment to the blowing force while the shim set is used as the “coarse” adjustment. EXAIR sells this kit as one model number for simple ordering, and the accessories are properly sized to not hinder the performance of the Super Air Knife.
To optimize the system even more, EXAIR offers a Deluxe Kit for the Aluminum and Stainless Steel models. This includes the accessories in the kit above, plus an Electronic Flow Control, or EFC. This exclusive instrument uses a photoelectric eye to start a timing sequence to control a solenoid valve. So, when a part is not in front of the Super Air Knife for cleaning or cooling, the compressed air is turned off. This will save you even more money and maximize your efficiency to only blow air when needed.
For the longer Super Air Knives, EXAIR can install a Plumbing Kit, or PKI, to help attach your compressed air to the Air Knife. They are designed to help lessen the time for install as well as to properly supply compressed air equally along the entire length, specifically for 24” (610mm) and longer. We can offer the Plumbing Kit separately if you find that it could benefit your fabricators during installation. EXAIR also offers a Coupling Kit for the Aluminum and Stainless Steel versions. If you need to extend past the 108” (2,743 mm) width, the Coupling Kit is designed to mount Super Air Knives together at the ends. You will still get that consistent blowing force along the multiple of Air Knives. Another helpful accessory is the Universal Air Knife Mounting System. It has a bracket and an articulated arm that can reach up to 30” (762mm). With this system, you can position your air knife securely and precisely in any orientation. It attaches easily to your Super Air Knife and gives you the flexibility to maximize the blowing effect at your target.
With the today’s cost in making compressed air, it is important to use it as efficiently as possible. The Standard and Full Flow Air Knives would be good options to use. But the best way to conserve is with the Super Air Knife. If you have any questions about the Super Air Knife or if you would like to discuss an application, you can contact an Application Engineer at EXAIR. We will be glad to help you.
On January 2, 1960 Little Anthony & The Imperials appeared on The Dick Clark Saturday Night Beech-Nut Show to sing Shimmy Shimmy Ko Ko Bop. While I wasn’t around at that time, I have heard the song quite a few times and get it stuck in my head more than I have heard it. What does that song and EXAIR have to do with each other? Well, we shimmy shimmy Super Air Knives to dramatically increase or decrease their flow and force.
The stock shim that is assembled in every Super Air Knife is a .002″ (0.05mm) thick. This sets a continuous opening the full length of the knife that drives the performance of the knife. The shim sets the gap height between the cap and the body of the Super Air Knife. If we evaluate a 24″ Super Air Knife with the stock shim installed we could calculate the airflow opening of the knife as the surface area of a rectangle. To obtain the surface area we take the length of the air knife times the thickness of the shim. See the example below.
As you can see with the stock .002″ thick shim installed we are actually operating at a surface area opening of 0.048 square inches. If we were to install the .004″ thick shim into the knife then we would double the height which in turn doubles the surface area, shown below.
This doubling effect will increase the force out of the Super Air Knife when applications require more power. Thinning out the shim will have the exact opposite effect, if the shim thickness is reduced to .001″ thick then the air consumption and force will be reduced.
Changing the shims out of the Super Air Knives is a fairly simple task as shown in the video below. Installing a different thickness of shim is a coarse adjustment to the volumetric flow needed for your application. Then a pressure regulator can be used to fine tune the needed force and flow for the ideal setting to meet your needs, and operate at maximum efficiency for the application.
If you would like to discuss this further or even see what kind of custom thicknesses we can offer on the shims to truly make a tailor fit Super Air Knife for your application, please contact us.
Little Anthony & The Imperials “Shimmy Shimmy Ko Ko Bop” – [Merlin] XelonEntertainment, WMG (on behalf of Turntable Recordings LTD); ARESA, LatinAutor, União Brasileira de Compositores, Spirit Music Publishing, UNIAO BRASILEIRA DE EDITORAS DE MUSICA – UBEM, Abramus Digital, BMI – Broadcast Music Inc., and 4 Music Rights Societies – https://www.youtube.com/watch?v=5mLjZRAXRRA
I spoke with an international agribusiness that specialized in improving processes with cutting-edge technologies in the agricultural sector. They started a project with a company to improve their drying process for potatoes. This company was washing 10 tons of potatoes per hour during 16-hour days. The potatoes would travel along a conveyor that was 90cm (35.4”) wide after the washing system where they had three blower air knives to remove the water from the surface. Since the project scope was to increase productivity, the agribusiness company targeted their biggest issue, the blower air knives.
They described the two main problems that their customer was experiencing. First, the conveyor had to run at a slower rate to remove enough water from the surface of the potatoes before packaging. Thus, the feed rate into the washing system ran intermittently to not overload the drying process. The main issue was that the blower system was limited with force. It could not generate a strong enough air stream to properly dry the entire spud at higher speeds. Thus, the conveyor system was not at an optimal range.
The second issue was premature spoilage of the potatoes which had to be discarded. I remember when my family would store potatoes in bunkers under the ground to keep them cool. This would help to slow the bacterial growth which causes spoilage. Blower systems generate hot air from the electric motors. Since bacteria growth is enhanced with warmer temperatures, the potato company was noticing poor appearance and early spoilage. To increase their profits, they wanted to dry the potatoes without heat.
EXAIR has been manufacturing leading-edge technology since 1983, and we could offer a solution. For removing water from the surface of the potatoes; the EXAIR Super Air Knife would be the perfect instrument. This compact system is easy to install; and it does not have any moving parts to wear or need shutdowns for maintenance.
I recommended to replace the three blower-air knives with one piece of a model 110236SS Super Air Knife Kit. The kit includes a 36” (914mm) 303SS Super Air Knife, a filter, a regulator and a shim set. The regulator and shim set are specifically designed to control the force requirement and air usage to the Super Air Knife. So, you can fine tune the correct amount of force to blow around the entire potato for effective drying. For a stock Super Air Knife, the model 110236SS can generate 5.6 pounds of force (2.55 Kilograms) at 80 PSIG (5.5 Bar); a tough target for a blower air knife. The agribusiness was excited about the concept and wanted to know more.
Another unique feature with the EXAIR Super Air Knife is the engineered design. We are able to reach a 40:1 amplification ratio. That means for every 1 part of compressed air, we can entrain 40 parts of ambient air. What does this mean? First, the Super Air Knife is very efficient within your compressed air system as we are using mainly free ambient air. Second, since majority of the air is ambient, the temperature of the air is not heated; thus, a cooler air stream. And third, by adding the mass of the ambient air, it gives a stronger blowing force. So, the Super Air Knife was able to meet both of the agribusiness requirements. In the end, we were able to cut scrap and increase the production rate by almost 10%.
If you need to dry your agricultural items with cutting-edge technology, EXAIR would be the manufacturer for you. We are staffed with Application Engineers to find solutions and improvements, and we will be happy to discuss your application. For this agribusiness company, they were excited to work with EXAIR to get a great result for the company above in the potato arena.
There’s nothing quite like an ice-cold Coke from McDonald’s. While there’s many reasons for this, one of the reasons for the unique experience of a McDonald’s Coke lies in the straw itself. In their drinks, they provide wider straws that are designed to help enhance the taste of Coca-Cola, or so they claim. Another impact of this is it allows you to drink significantly faster. The wider the opening for liquid to pass through, the more volume you’re able to drink. Imagine trying to drink your Coke, or any other beverage, through a coffee stirrer. I imagine you’re going to have a difficult time and a dry mouth as you try and force what little amount of liquid you can through the small I.D. of a coffee stirrer. Try that with a milkshake and the problems compound…..
The same is true when it comes to plumbing of your point-of-use compressed air products. I recently assisted a customer that was experiencing lackluster performance from the Super Air Knife they purchased. The application was fairly straightforward, they were hoping to reduce the rate of rejected material on their production line of plastic sheets. The sheet goes through a washing process to remove any residual contaminants, then would air dry as it made its way down the line. As the material dried, there were water spots left on the material that would have to then be cleaned off. In the hopes of speeding up the drying process, they purchased a Model 110060 60” Super Air Knife to provide a wide laminar sheet of air to dry the material.
When they hooked everything up, the flow from the knife seemed far less than they were expecting. They were supplying full line pressure (just over 90 PSIG), so in theory they should feel a strong blast of air from the knife. When they installed a pipe tee and pressure gauge directly at the inlet, they noticed the pressure was dropping to 35 PSIG while the knife was in operation. When this occurs, it’s indicative of a lack of volume of air. This can be caused by undersized compressor, or improper plumbing. In their case, they were only plumbing compressed air to one center inlet of the knife. For a 60” knife, EXAIR recommends a minimum of (4) air inlets to ensure adequate volume.
The size of these lines is also critical. You can’t force greater volumes of air through a smaller hose or pipe, just like you can hardly drink through a coffee stirrer with any great success. A 60” knife requires a supply pipe size of 1-1/2” for up to a 50’ run, if you’re trying to supply a knife of this length with a 100’long, ¼” ID hose, you’re not going to get the performance you expect. If you’re experiencing less than optimal performance from any of your EXAIR Intelligent Compressed Air Products, there’s a good chance air supply is the culprit. The first step is determining what the actual inlet pressure is, install a pipe tee and pressure gauge right at the inlet. Then, give us a call and we’ll help work through the proper line sizes and ensure that you’re getting the most out of our products.
I hope I didn’t make you hungry or thirsty… But I think I know where and what I’m having for lunch 😊!