Maintenance on Blower Knives Vs Compressed Air Knives

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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Twitter: @EXAIR_JS

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

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

EXAIR Super Air Knife Helps Bakery Protect Sheet Pan Coating

A bakery had a process where they cleaned baking sheets after they made cakes, breads, and donuts.  The system consisted of scraping the pans with brushes prior to running them through a washing system.   The excess crust material had to be removed as it could cause problems with the washing machine.  The baking sheets had a non-stick coating to help in the baking process.  The issue that they were having was that the brushes would start to remove the non-stick coating over time, causing the pans to rust.  If you needed more iron in your diet, this would not be the proper way.  The baking sheet was 18” (457mm) wide by 36” (914mm) long.  They contacted EXAIR to see if we had a better way to clean these sheets without damaging the coating. 

EXAIR has been supplying powerful non-contact ways to clean, dry, and cool products.  For this application, I recommend the model 110218SS Super Air Knife Kit.    The kit includes an 18” (457 mm) 303SS Super Air Knife, a filter, a regulator, and a shim set.  The stainless-steel construction would protect against the harsh detergents that are used in the process.  If additional protection is required, EXAIR also provides 316SS material.  The unique feature of the Super Air Knife is that it entrains ambient air at a rate of 40:1 to deliver a hard-hitting force with a small amount of compressed air.  In addition, the filter would capture any contamination from the compressed air line to keep the surface clean.  The regulator and shim set would be used to control the amount of force required to remove the debris. 

The Super Air Knife was placed just before the washing system to remove the baked contamination.  The brush system was removed.  As a bonus, they realized that they did not need to replace the brushes quarterly, which added replacement costs and maintenance time.  Sometimes these savings are overlooked.  The setup was really easy, as they only had to run compressed air to the Super Air Knife and mount anywhere from 3” (76mm) to 12” (305mm) from the sheet instead of having to periodically adjust the brushes due to the bristles shortening.

After the installation, they were amazed at the power of the Super Air Knife.  And with the non-contact cleaning, the non-stick surface was able to last much longer without having to replace the pans.  Currently, the baking sheets are lasting twice as long as they were before they started using our product.  If you have an application, where you would like to protect the surface, EXAIR has a variety of products that can create a non-contact way to clean, dry, and cool.  An Application Engineer can assist you. This customer above could now have their cake and eat it, too.

John Ball
Application Engineer


Email: johnball@exair.com
Twitter: @EXAIR_jb

EXAIR Products Entrain FREE Ambient Air For Maximum Force and Flow

Air entrainment is a term that we bring up quite often here at EXAIR. It’s this concept that allows many of our products to dramatically reduce compressed air consumption. The energy costs associated with producing compressed air make it an expensive utility for manufacturers. Utilizing engineered compressed air products that will entrain ambient air from the environment allow you to reduce the compressed air consumption without sacrificing force or flow.

Products such as the Super Air Knife, Super Air Nozzle, Air Amplifier, and Super Air Wipe all take advantage of “free” air that is entrained into the primary supplied airstream. This air entrainment occurs due to what is known as the Coanda effect. Named after renowned Romanian physicist, Henri Coanda, the Coanda effect is used in the design of airplane wings to produce lift. As air comes across the convex surface on the top, it slows down creating a higher pressure on the underside of the wing. This creates lift and is what allows an airplane to fly.

EXAIR Super Air Nozzle entrainment

This is also the same principle which is allowing us to entrain ambient air. As the compressed air is ejected through a small orifice, a low-pressure area is created that draws in additional air. Our products are engineered to maximize this entrained air, creating greater force and flow without additional compressed air. Super Air Amplifiers and Super Air Nozzles are capable of up to a 25:1 air entrainment ratio, with just 1 part being the supplied air and up to 25 times entrained air for free!! The greatest air entrainment is achieved with the Super Air Knife at an incredible ratio of 40:1!

This air entrainment principle allows you to utilize any of these products efficiently for a wide variety of cooling, drying, cleaning, or general blowoff applications. In addition to reducing your compressed air consumption, replacing inefficient devices with engineered products will also dramatically lower your sound level in the plant. Sound level in some applications can even be reduced down to a point that would eliminate the need for hearing protection with the OSHA maximum allowable exposure limits set at 90 dBA for an 8-hour shift.

If you have inefficient blowoff devices in your facility, give us a call. An Application Engineer will be happy to help you select a product that will “quietly” reduce your compressed air consumption!

Tyler Daniel, CCASS


Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD