How To Choose An Air Knife

The EXAIR Super Air Knife has a prominent place near the front of our catalog, and THIRTEEN pages of photos, application details, performance data & specifications. It’s the most efficient and quietest product of its kind on the market, and our most diverse product offering in terms of size range, operational adjustability, materials of construction, and accessories available. For almost any general industrial air blow off application, the EXAIR Super Air Knife is the superior choice in terms of air usage, sound level, and capability.

EXAIR Super Air Knives come in a wide range of lengths, for a wide range of possibilities.

EXAIR Super Air Knives come in a wide range of lengths, for a wide range of possibilities.

As tireless champions of the causes of reducing air consumption and noise, we’re always going to promote these benefits of the Super Air Knife. Still, a caller asked me the other day, “Well, why do you still make the others?”…meaning, of course, our Standard and Full Flow Air Knives. Why, indeed:

*Given the same air supply pressure, the Standard Air Knife generates the highest force of our three styles. The amount of force applied isn’t always a prime consideration…if you think about one of the more “textbook” applications for an Air Knife, it doesn’t take a great amount of force to blow off dust and light debris from a conveyor belt…certainly this is a case where efficiency factors in: the lower air consumption of a Super Air Knife can pay for the cost difference between it and a Standard Air Knife in as little as three months of operation.

The Standard Air Knife has the highest force, for when it's needed.

The Standard Air Knife has the highest force, for when it’s needed.

Of course, if you’re blowing stubborn debris out of tight spaces, like gummy, greasy dirt that’s accumulating in the recesses of a finned tube heat exchanger, that extra force can make all the difference. No; the Standard Air Knife isn’t as efficient or quiet as the Super Air Knife, but it’s still a far cry better than a drilled pipe.

*While the Super Air Knife is pretty compact – you only need a few square inches of profile area to successfully mount it – the Full Flow Air Knife is even smaller, requiring not much more than one square inch of profile for mounting. With ports on the rear face (instead of the ends & bottom for the Super Air Knife,) they can fit in very tight quarters.

Low profile and lightweight, the Full Flow Air Knives are a great fit for tight quarters.

Low profile and lightweight, the Full Flow Air Knives are a great fit for tight quarters.

The Full Flow Air Knife is also the lightest weight for a given length. A 36” Aluminum Super Air Knife, for instance, weighs about 8lbs. The 36” Aluminum Full Flow Air Knife weighs less than 4lbs. Most of the time, 8lbs is a very manageable amount of mass to support, but there are situations where every ounce matters, and if yours is one of them, you’re looking at the Full Flow Air Knife all the way.

*The biggest (in the most literal sense) factor in Air Knife selection is, well…size. We make the Standard Air Knives in lengths to 48”, and the Full Flow Air Knives come as long as 36”. The Super Air Knives, however, are stocked in lengths from 3” to 108”, and can be coupled together for as long of an uninterrupted, steady, laminar air flow as you need.

At the end of the day, a majority of blow off applications can be handled just fine with any of our Air Knives. If you’d like to discuss your application and see which one is best for you, give us a call.

Russ Bowman
Application Engineer
(513)671-3322 local
(800)923-9247 toll free
Find us on the Web
Follow me on Twitter
Like us on Facebook

Chain-Chain-Change, Change Out That Drilled Pipe…

Life is full of change.  It might sound trite, but truer words were never spoken.  I used to get up around 6:30 on work days.  Now, thanks to my son’s middle school schedule, I’m usually seeing him out the door at that time.  Getting up earlier was certainly a difficult change at first, but it’s had its benefits.  Not the least of which is spending a little extra time with the boy in the morning.

One of our favorite things to do while eating breakfast is to watch the ‘How things are made’ types of shows. Of course, watching these types of shows with an engineer has its downside.  While we can usually explain exactly what’s happening in the process of whatever is being made, the problem is that we often do.  Meaning we wind up talking over the program, which, ironically, is one of my greatest pet peeves.  Speaking of change, guess that’s something I need to work on…

20141002_062454

At any rate, this morning we saw a show on making saltines.  At the sight of the copper pipe positioned near where the cracker dough comes off the die-cut wheel, I knew exactly what was up. ‘They’re using drilled pipe! That’s not safe and a HUGE waste of compressed air!  That’s the perfect application for a Super Air Knife!”  Guess watching these programs with an EXAIR engineer has an additional risk: We can get a little over-excited when we see OSHA violations and wastes of compressed air! I think I about made my son jump out of his gym shorts, but he’s watched these sorts of shows with me before.  He knew the risks…

Life is full of change, and while perhaps I can get better at not talking while the TV show is on, I doubt I’ll ever stop cringing at safety violations and wasting compressed air.  Do you have drilled pipe in your plant?  If so, you could be in violation of multiple safety standards and are definitely wasting money on compressed air.  EXAIR can help you minimize harmful noise levels and keep you in compliance with OSHA’s dead-end pressure standard. Please give EXAIR a call to begin saving air and increasing safety!

Dan Preston
Engineer-at-large
DanPreston@exair.com
1-800-903-9247

 

 

A Dull Knife Is A Dangerous Knife

Anyone who’s ever cooked, hunted, crafted, fished, whittled, opened a well sealed package, or sharpened a stick for roasting marshmallows knows what I mean. A dull knife requires more force to cut your material, which means that you’re using less of your muscle strength to control the blade. If you’re not sure of where the blade is going, that’s a heck of a thing to leave to chance, especially if you’re holding what you’re cutting in your other hand.

Even if (I might even say “especially if”) you don’t use a knife for cutting every day, the conventional wisdom dictates that you should keep its blade sharp. Not only is this imperative for safety reasons (see above,) but you’re going to make a MUCH higher quality cut as well.

Sharp blades result from high quality material that is professionally crafted, and expertly maintained. The cheaper the material, the easier the blade will dull. High carbon stainless steel blades cost a little more, but they’re also easier to sharpen, and they stay sharp longer. A decent stamping machine can turn out hundreds of blades an hour, but forging a single piece of metal results in a level of hardness that is much more conducive to maintaining a sharp edge. Speaking of maintaining a sharp edge, that’s going to be left up to the user. A lot of hardware stores provide sharpening services, but it’s not all that hard. Expert results can be obtained by following what the experts do, and the Boy Scouts of America have taken pride in doing stuff like this for over a hundred years now. Full disclosure: I’ve been a Scout Leader for over nine years now, so I may be biased, but I am unapologetically so. I use these tips, and my pocketknife is VERY sharp.

High quality material, professionally crafted and expertly maintained, is, of course, a successful recipe for a great many products other than knife blades. EXAIR applies these principles to every single item in our 168-page catalog of Intelligent Compressed Air® Products. Here are just a couple of examples:

*The Super Air Knife (no relation to the cutting tools discussed above) is available in a range of materials: aircraft grade aluminum, types 303 or 316 stainless steel, or PVDF. They’re engineered for maximum efficiency, minimum noise level, and manufactured to exacting quality standards.

Capture
*The Heavy Duty HEPA Vac System turns your open top drum into a powerful, high capacity, dust free, industrial vacuum. It’s made of a hardened alloy for superior abrasion resistance, and, with no moving parts, it’s virtually maintenance free.

Exair-heavy-duty-HEPA-vacuum

I could go on, but these are the two products, and the benefits they provide, that I’ve actually discussed with potential users just today. If you’d like to know more about how EXAIR products can keep the use of your compressed air sharp, effective, and safe, give me a call.

Russ Bowman
Application Engineer
Visit us on the Web
Follow me on Twitter
Like us on Facebook

Shared Details Equal Better Solutions

Fortunately for us, and our customers, we manufacture custom parts to meet their application if our cataloged products do not meet their requirements. Just look at these blogs. Customers often come to us to know if our products can be used in a corrosive environment, or if they are suitable within a high temperature, or within a small envelope.  Shortly after I started working in the Application Engineering department, I have found that the answers to these questions are generally “Yes, but why?”

Our marketing department does a great job of displaying our capabilities.  Just look at the special pages: Air Knives, Line Vacs, Air Amplifiers, or Cabinet Coolers. We can make a great variety of products and materials, but we always will ask the next question. Why?

Some customers are surprised at how emphatic we can be about knowing why you need a special part or process. We are only asking to best serve you. For instance, I had a customer come to me today after seeing our Special Air Knife page and seeing our flat Super Air Knife that is only 11/16″ thick.  This is a great product for its application, but when compared to our stock Super Air Knife, it is more expensive and carries and cannot be shipped until 2-3 weeks after it is ordered since we would build it from scratch.  Customers first look at the Super Air Knife and see that the overall height of the product is 1.44″, which is too large to fit in their machine.  When they see that the Super Air Knife is too big they assume they need something special.  This is generally, when I get a call like this.

“I need your Flat Super Air Knife. What is the part number and price?”

Flat Super

“We don’t have a standing part number for that unit. It was a special part that we created for a specific customer. Why do you need that model?” I reply.

“It is thinner than the Super Air Knife.” – customer

“Have you looked at the Full Flow Air Knife?” – my reply

“No, What is that?” – customer

This is where the reasoning behind the request is so important. Purchasing one piece of a custom made thin Super Air Knife pictured above is significantly more expensive than the production run and in stock Full Flow Air Knife.  The Special thin Super Air Knife is 0.688″ thick. The Full Flow Super Air Knife is 1.03″ thick. And in this case case, the Full Flow Air Knife worked for this customer.  This is just one example of finding out why a customer needs a special product is so important.  If the machine envelope is 1.25″ the Full Flow Air Knife will fit just fine. If the machining envelope is 0.75″, a Special thin Super Air Knife will be the solution. When we share the details together, it is easier to produce the best solution for our customers.

Dave Woerner
Application Engineer
DaveWoerner@EXAIR.com
@EXAIR_DW

Cooling Efficiently

Last week, I had the opportunity to work with a customer who was trying to cool a thermoformed film from 85° C (185° F)  down to room temperature, 21° C (69.8° F) or low enough for the package to be handled by an operator. This container was 270 mm X 170 mm X 100 mm (10.63″ x 6.69″ x 3.94″)

Thermoformed packaging

In applications like this, the customer often calls in with the idea of using a Vortex Tube to produce the cold air.  There are two reasons to use a different product than a vortex tube in this application. First, a vortex tube is only going to cool a small area, so to cool anything this size would take several vortex tubes.  Second, the cold air is going to mix with the ambient air very quickly. When the ambient air mixes with the cold air from the vortex tube, the air will lose the cold temperature generated by the vortex tube. To counter act this mixing, we have had customers create an insulated container to hold cold air from a vortex tube close to a product, similar to a cooling tunnel. This works in some applications, but my customer had a continuously moving line. He did not have time to stop the line and install insulation around each product.  He also didn’t have the length of conveyor needed to put a cooling tunnel over the line.

Super Air Knife Promo

Instead of using the vortex tube, I suggested that he use a 12” (305 mm) Super Air Knife to cool the thermoformed container. The 12” Super Air Knife moves significantly more air than a vortex tube over the surface of the part. Thanks to the 40:1 amplification ration of the Super Air Knife, it creates more cooling to the product and use less compressed air than a series of Vortex Tubes.  By mixing a large volume of free ambient air, that is the same temperature he needs to cool the part to, and a small amount of compressed air over the product they can easily cool their part to close to ambient so the operator can handle the part. The best benefit for this customer was they would not need change their manufacturing line.  The air knife is the best choice when cooling a very hot, fairly flat, large surface part to a temperature close to ambient. If you need to cool a product to a temperature lower than room temperature, then a vortex tube would be a great product to do the job.

Dave Woerner
Application Engineer
DaveWoerner@EXAIR.com
@EXAIR_DW

Super Air Knives Provide Needed Blow Off

Dust hood

I had the pleasure of working through an application in which uncooked hamburger buns are processed and baked.  In the application, dough patties travel along a conveyor into an oven and a small, targeted blow off (technical term: “fluff”) is needed to remove excess flour.

When the flour is blown off of the dough, it is extracted by a system mounted above the conveyor.  The difficulty for this end user was in finding a reliable, laminar solution with consistent blow off force.

Enter the EXAIR Super Air Knife.

By installing an EXAIR Super Air Knife (in the appropriate material), the uneven and inefficient blow off that was originally installed was replaced with a reliable and quiet solution.  We were able to take a problematic application and turn it into a repeatable process.  And, we were able to repeat success in another similar application at another point in the same facility.

If you have an application in which repeatable, reliable, efficient solutions are needed, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE

EFC Can Provide Valuable Compressed Air Savings

I recently worked with a customer who was wanting to use one of our 72” Super Ion Air Knife is his paint booth application. He would be using the Super Ion Air Knife to remove any static build up and blow dirt/debris off ABS plastic molds (truck beds) prior to the paint booth. We were both confident the Super Ion Air Knife would perform in the application but he was concerned with the amount of air he would be wasting in between paint cycles. The paint time for each mold is 5 minutes and the blowoff time is 30 seconds, he was planning to leave the knife run during this time. This is an 8 hour per day operation, Monday – Friday, so this practice was going to lead to an expensive waste of compressed air*. I recommended that he incorporate our EFC (Electronic Flow Control) into his process.

Without using the EFC

(* Using $ 0.25 per 1000 SCFM used)

  • 72” Super Ion Air Knife = 208.8 SCFM @ 80 PSIG
  • 208.8 SCFM x 60 minutes x $ 0.25 / 1000 SCFM = $ 3.13 per hour
  • $ 3.13 per hour x 8 hours = $ 25.04 per 8-hour day
  • $ 25.04 x 5 days = $ 125.20 per work week
  • $ 125.20 per week x 52 weeks = $6,510.40 per work year without the EFC control

The EFC is an electronic flow control that minimizes compressed air usage by incorporating a timing controlled (0.10 seconds to 120 hours) photoelectric sensor. The unit will turn off the compressed air supply when there are no parts present and provides an easy way to program the device to a specific application. The EFC offers an additional eight programmable on/off modes and is suited for NEMA 4 environments. It can also be easily wired for electric, 100-240VAC, 50/60Hz.

EFCp4

With the EFC installed (turning the air off for 4.5  minutes with a 30 second cycle time = 6 minutes/hour compressed air usage)

  • 208.8 SCFM x 6 minute x $ 0.25 / 1000 SCFM = $ 0.31 per hour
  • $ 0.31 per hour x 8 hours = $ 2.48 per 8-hour day
  • $ 2.48 x 5 days = $ 12.40 per work week
  • $ 12.40 per week x 52 weeks = $644.80 per work year with the EFC control 

$ 6,510.40 per year (w/o EFC) – $ 644.80 per year (w/ EFC) = $5,865.60 projected savings per year by incorporating the EFC.

This example illustrates, clearly, why choosing the EFC is a good idea. It has the ability to keep compressed air costs to a minimum and saves compressed air for use within other processes around the plant. With this type of compressed air savings, the unit would pay for itself in less than 3 months.

If you would like to see how we might be able to improve your process or provide a solution for valuable savings, please contact one of our Application Engineers.

Justin Nicholl
Application Engineer
justinnicholl@EXAIR.com
@EXAIR_JN

Follow

Get every new post delivered to your Inbox.

Join 815 other followers

%d bloggers like this: