Tag: air knifes

Combining Products For Total Blow Off Of Objects With Complex Geometry

Published on by Russ BowmanLeave a comment

EXAIR Super Air Knives are extremely efficient at blowing off flat surfaces. The laminar air flow they generate makes a stripping/sweeping action, as opposed to the turbulent flow from a non-engineered blow off, which really just beats on the surface. If the object being blown off, though, has features such as holes, recesses, grooves, bosses, “nooks & crannies”, etc., it may be challenging to get those features 100% blown off, 100% of the time.

If the object you’re blowing off is flat, the laminar air flow from a Super Air Knife is ideal. They come in lengths from 3 inches to 9 feet long.

Depending on the size & shape of the feature presenting the challenge, the first thing we might recommend is to adjust the angle at which the Air Knife’s flow contacts the surface. For most applications, you can optimize performance by blowing at as low of an angle as practical. You may need to aim the Air Knife at a steeper angle, for example, if you’re blowing off something that’s dense (like shot blast or garnet, as opposed to dust or chips), or if it’s somewhat adherent to surface (like grease or mud, as opposed to water or light oil). This can also work if you’re trying to blow out a hole, recess, or groove in an object.

EXAIR manufactures a wide variety of engineered Air Nozzles, designed for safety, efficiency, and quiet operation.

Other times, a dedicated blow off may be necessary to pick up where the Air Knife leaves off. In situations like that, we can specify an appropriately sized Air Nozzle, Air Jet, Air Amplifier, or maybe even a smaller Air Knife, to provide more complete removal of whatever you need to get off of the object. It’s fairly common to use Air Nozzles for these applications, and our Air Nozzles & Jets catalog section is a great tool that can be used for selection. It lists them all, from smallest to largest, with airflow patterns, performance data, and dimensions.

EXAIR offers solutions for plumbing, installation, and aiming the Air Nozzle too:

  • Swivel Fittings are installed on threaded pipe, and provide 50° of angular movement. Just loosen the lock nut, aim the Nozzle, and re-tighten for rigid & secure placement.
  • Stay Set Hoses are likewise be threaded into 1/4 FNPT connections, with the Air Nozzle secured onto the other end. These come in lengths from 6″ to 36″, with 1/8 FNPT or 1/4 MNPT threads for the Air Nozzle.
EXAIR Stay Set Hoses and Swivel Fittings are ideal for installation and positioning of your Super Air Nozzle.

Metal tubing with compression fittings is another option, that can be used to install & aim an Air Nozzle. Copper tubing is relatively easy to bend by hand. Stainless steel tubing usually requires a tube bender tool, with the advantage that it can’t easily be bent by hand…on purpose or by accident. While metal tubing is certainly an option, it is generally reserved for applications where the ability to readjust is not necessary. The Stay Set hoses and Swivel Fittings tend to work better when flexibility is required.

The copper tube used to have a crimped end that was aimed at the part in the chuck. They simply cut it off and used a compression fitting to install the Super Air Nozzle.

If you’ve got a blow off application that’s not working the way you want it to, it’s highly likely that EXAIR has a solution. We would love to share our ideas with you. Give me a call.

Russ Bowman, CCASS

Application Engineer
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Optimizing Your Compressed Air Usage With Engineered Products

Published on by Russ BowmanLeave a comment

The first new car I ever bought was a 1995 Ford Escort Wagon. I’ve mentioned this before in posts about preventive maintenance, the importance of proper filtration, and brand loyalty. Those blogs were primarily about my experiences with that little red wagon, but today I wanted to discuss the primary reason I bought the car in the first place.

I had a 50-mile round trip commute to work, and my old Pontiac Grand Prix with the small block V8 engine was a great ride for sure. Some quick math, however, showed that if I went with something with better gas mileage, I could save quite a bit of money on gasoline. My calculation was almost $1,000 a year, just on driving back & forth to work. After figuring in the rest of my driving for the first year, it was more like $1,400 a year.

Similar to my “upgrade” to a more fuel efficient vehicle, upgrading blowoff, cooling and drying operations using engineered compressed air products is Step #3 in EXAIR’s Six Steps To Optimizing Your Compressed Air System. We’ve assigned an order to these steps in accordance with basic good engineering practice & protocol, but it’s not necessary to follow them in any particular order. In fact, all six steps really don’t apply to every single compressed air system.

Step #3 does apply to most systems, though. I spent a fair amount of time in all sorts of industrial facilities in my previous roles, servicing industrial & chemical pumps, and almost all the time, regardless of the industry or the size of the facility, the maintenance part of the facility used air guns. However, I don’t recall ever seeing an engineered nozzle on one before I came to EXAIR. Since then, I’ve worked with a BUNCH of users to dramatically reduce compressed air consumption by replacing their cheap and inefficient air guns with EXAIR Safety Air Guns, or by retrofitting EXAIR Super Air Nozzles onto their existing air guns. We actually carry adapters to fit our Super Air Nozzles to a number of readily commercially available air guns for that very purpose.

The five families of EXAIR handheld blowoff products include VariBlast Precision & Compact, Soft Grip, Heavy Duty, SuperBlast, and TurboBlast Safety Air Guns. They’re available with a range of engineered Super Air Nozzles, Extensions, and Chip Shields.

In addition to air guns & nozzles, our Air Knives have a long history of replacing drilled pipes & pipe manifolds with inefficient nozzles used to make a curtain of air flow. The following chart details the savings you can realize from the use of a 24″ Super Air Knife instead of similar devices for a 24″ wide air curtain:

Even though an electric powered blower will use less electricity than the amount of electricity an air compressor uses to supply an engineered product like the Super Air Knife, the maintenance costs make the total cost of ownership eclipse that of the engineered Air Knife.

Our Case Study Library (registration required, but it’s free & fast) documents many real-world situations where customers worked with us to gather & publish “before/after” documentation, proving out the benefits of Step #3. I encourage you to check those out, and if you think you might have an opportunity to do a Case Study with us, we offer discounts or credit for that…give me a call.

Russ Bowman, CCASS

Application Engineer
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Maintenance on Blower Knives Vs Compressed Air Knives

Published on by Jordan T ShouseLeave a comment

The EXAIR Super Air Knives as well as most of EXAIR products have no moving parts! What does that mean, well with no moving parts that means there are no parts to wear out! Other than changing a compressed air filter element here and there (somewhere around $30-$50 bucks) and opening the knife to clean it. That is it!

Clip from the Super Air Knife Install and Maintenance guide

Blowers on the other hand are a whole different story, there are LOADS of moving parts resulting in downtime and numerous replacement parts. I’m just going to cover the main ones!

Belts and Tensioners

Just like you car your blower motor and blower heads are connected by a rubber belt and tensioner to keep it tight and clean. Over time since there is so much vibration and movement these belts can start to wear down or tear, leading to a 1-2 Hour downtime to find and repair the issue. The same thing will happen with the bearing in the Tensioners.

Tearing Belt
Belt Tensioner

Blower Heads and Motors

All high speed rotating equipment will eventually fail, due to normal wear of seals and bearings. So you either need a spare which can be a pricey investment or your operation will be down until you get it repaired or swapped out by the manufacturer.

Blower Motor and Head

Filters

Blowers have an inlet filter installed. However, rather than filtering the compressed air like a compressed air knife (within the enclosed compressed air line) blowers filter the ambient air around the blower (within the application space). So if your facility is dirty and dusty these filters are going to succumb to the various, environmental contaminations rather quickly.

To break that down a little better!

System Maintenance:

  1. Blower System – The intake filter has to be changed periodically as well as the motor and belt has to be checked as a preventive maintenance. Being that the blower motor is a mechanical device, the bearings and belts will wear and have to be replaced.  Without proper maintenance, things can break prematurely.  Loss of production will cost your facility revenue on the bottom line.
  2. Super Air Knife – They do not have any moving parts to wear out. Only compressed air is needed to operate.  The maintenance requirement is to change the compressed air filter once a year.

When you bring the whole picture into view the total cost of ownership is quite clear when you look at loss of output, loss of product, and breakdown of equipment. Yes the power generated in some cases by the compressor can be more than a blower. But when you look at purchase price, installation cost, and maintenance, the compressed air operated, Air Knife is the clear winner.

Compressed air can be expensive, but if you use EXAIR products, you can use the compressed air very efficiently.  You do not have to sacrifice other areas within the total cost of ownership.  If you have a similar application, you can contact an Application Engineer at EXAIR.  We will be happy to discuss the benefits of using the EXAIR Super Air Knives over a blower-type air knife.

Jordan Shouse
Application Engineer

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Tearing belt image courtesy of jblevine2004 Via Creative Commons

Blower Motor and Head image courtesy of Ragtimer1 Via Creative Commons

Belt Tensioner image courtesy of Cordylus Via Creative Commons

BELIEVE

Published on by Brian FarnoLeave a comment

Okay, in case you haven’t been around the past year or two, and you have no clue where that simple word/statement comes from, then let me be the first to tell you that Ted Lasso is a great show, and you should check it out. So what does that have to do with EXAIR? Well, I like to think that sometimes the Application Engineers here are a lot like the coaching staff on the show. Sometimes we are strategic, we want to assert our experience and knowledge, and others, we are like Ted where we just ensure the thoughts and ideas you have already had.

That’s the fun part of being an Application Engineer here at EXAIR. I get to speak, chat, or email with both existing customers and potential new customers, resellers, and even catalog houses who all are trying to do one thing, improve a process or help someone out. Recently I was working with a manufacturing company trying to determine how fast they can cool a slab of steel with a Super Air Knife. Now, I by no means have a background in thermo like Russ Bowman, but he was busy preparing for our Spring Webinar to share some knowledge on Compressed Air System Storage. (If you haven’t checked a webinar out, most are available on our website in our knowledge base. ) So, I took the time to try and remember some of the tools I learned while at the University of Cincinnati. Thermodynamics was by far one of the hardest classes for me, The Algebra was always easy, I just always looked at the problems sideways I guess, and worried about too many variables. The truth of it is, if you keep it simple you can generally get somewhere close. so I took that approach. First I looked at what heat load would be generated by the steel slab.

\K.I.S.S. – Keep It Simple Stupid – Not always my forte!

I looked at the basic Heat Transfer equation – Q=c x m x ΔT where:

Q = Heat
c = specific heat capacity
m = mass
ΔT = Change in temperature

I was able to locate the mass of the carbon steel plate with 1/2″ thickness. So I calculated the mass of the sheet. Then looked up the specific heat of the same plate, and took the change in temperature from what the customer stated the plate started at and finished at.

This resulted in a heat load. Then to calculate how much cooling a Super Air Knife could provide I utilized another calculation that gives the BTU constant of a cubic foot of air moving and I did decrease the efficiency of the knife due to some assumptions on space and temperature constraints. The resulting factor was the customer would need 6 Super Air Knives to blow the sheet down as it travels 5 feet per minute on a 60′ long conveyor.

This again had several assumptions and I made that very clear to the customer. To convert the amount of air a Super Air Knife puts out and how much cooling it can use, I did make some clear assumptions on the temperature of their atmosphere and the amount of entrainment then I used a calculation that we adapt for Vortex Tubes and Cabinet coolers to determine what cooling load will be achieved if the air pressure or temperature is less than optimal on one of those products.

In the end, the customer received an educated estimation or calculated answer with listed assumptions, to solve their issue with cooling a steel slab before it is stacked together. I really only used two calculations and manipulated some variables to try and make sense of what I knew and what the customer needed. The best part is, this whole process is backed by our 30-day guarantee on stock products which our 48″ Super Air Knife is. So this customer can take my basic math, use my suggestions, place an order, and test it out in their facility for a factual performance test to then proceed with a permanent solution.

If you would like to discuss any point of use or potential application for compressed air in your facility, please contact an Application Engineer today!

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF