Nozzle Separation

We have customers that call because they feel the pressure of trying to save money by saving compressed air.  One such customer that contacted us for this exact reason, had an operation that was working fine, but management had to reduce cost by saving compressed air.  The operation included a robotic “pick and place” machine to move sheets of corrugate from a stack to a converter machine.  When they first started their operation, they had issues with the corrugate “sticking” together.  The speed of pulling the corrugate from the stack would create a vacuum strong enough to pull the sheet behind it.  This would cause the operation to stop.  To fix this issue, the maintenance manager placed a ¼” (6 mm) poly tube at each corner of the stack to help separation.  This would break the seal between the two sheets, allowing only one to be picked.  The problem was solved.  Or was it?

Sometimes when you place a band aid on a situation, you can cause problems in other areas.  The other area in this case was on the side of money to make the compressed air.  More companies are trying to save money by being more efficient with their compressed air usage.  The quickest and easiest way is by retrofitting open tubes and pipes with EXAIR’s Super Air Nozzles.  With this application, the customer used the model 1122 Flat Super Air Nozzle.  It is specifically designed to create a wide flat air stream.  The tube would create a round pattern hitting a larger area than the target area.  Being that the target area is just between two flat cardboard pieces, the Flat Super Air Nozzle can localized the compressed air to make it more effective.  Because it was more efficient and effective, we were able to reduce the number of compressed air blowing points from four to two.

Model 1122 Super Flat Air Nozzle

Model 1122 Super Flat Air Nozzle

After the suggestion of the model 1122 Flat Super Air Nozzles, the maintenance manager, of course, asked “How much will it cost me”?  This is an interesting question.  Compared to the initial cost against a poly tube, we are higher.  But, over time, the poly tube will cost him much much more.  Here is an estimation:

Model 1122                                                                        Model 1122

Imperial units                                                                    Metric units

Qty: 2 pcs. per machine                                                 Qty: 2 pcs. per machine

Flow: 21.8 SCFM per nozzle @ 80 psig                     Flow: 622 SLPM per nozzle @ 5.5 bar

Total per machine: 2 * 21.8 = 43.6 SCFM                Total per machine: 2* 622 = 1,244 SLPM

¼” Poly tube                                                                      6mm Poly tube

Imperial units                                                                    Metric units

Qty: 4 pcs. per machine                                                 Qty: 4 pcs. per machine

Flow: 33 SCFM per tube @ 80 psig                            Flow: 934 SLPM per tube @ 5.5 bar

Total per machine: 4 * 33 = 132 SCFM                     Total per machine: 4 * 934 = 3,736 SLPM

 

For each machine, the model 1122 Super Flat Air Nozzle will save the company, 132 – 43.6 = 88.4 SCFM (3,736 – 1,244 = 2,492 SLPM) of compressed air.

Perhaps you can see the savings in compressed air.  But, people understand money better than SCFM or SLPM.  So, let’s look at the amount of money that they will save over a year.  The cost to produce compressed air is roughly $0.25/1000 cubic foot of air (This is an estimation on the average price per KWh of electricity in the U.S., $0.10/KWh).  For an 8 hour operation, the yearly amount of time in minutes is 60 minutes * 8 hours * 250 days = 120,000 minutes/year.  With a quick calculation, we get a savings of 88.4 SCFM * 120,000 minutes * $0.25/1000 SCF = $2,652/year per machine.

If we look at the ROI for this, the model 1122 has a price of $62.00 ea.  Each machine would require 2 pcs. * $62.00 = $124.00.  The ROI will be about 12 days.  So, when the maintenance manager asks me “How much will it cost me?”, I believe he meant to say, “How much will it save me?”.  If you ever need to save on compressed air and money, you can contact one of our application engineers to help you.

 

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Turbulent vs. Laminar Flow

I visited my family in Kentucky, and we went to the spillway at Cave Run Lake in the Daniel Boone National Park.  At the beginning of Licking River, there is a large pipe that drains from Cave Run Lake.  Kentucky had quite a bit of rain and the lake was very full.  The pressure from the lake was pushing lots of water through the drainage pipe.  It emptied into a cement channel and then into the mouth of the river.  As seen in the picture below, the water behaves violently as it exits the pipe and goes into the channel.  This turbulent state is loud and chaotic, and you can see the waves traveling upstream.  After the channel, the water transformed, and the river was quiet, calm and all flowing in the same direction.  This helped me to create a visual on how compressed air must look.

 

From Channel to River

From Channel to River

Turbulent Water from Pipe

Turbulent Water from Pipe

 

Even though we cannot see compressed air, it follows the same rules as a fluid.  Like the water coming out of the drainage pipe, the turbulence represents the flow of compressed air from an open pipe or copper tube.  The noise was extremely loud and the water was traveling side to side and back on itself.   You can see the inefficiency.  But after the channel, you can see the transformation to a laminar state.  EXAIR Super Air Knives and Super Air Nozzles do this with compressed air.  The laminar flow of air is quiet, and it efficiently works together.

Turbulence is useful for mixing, but horrible for reducing noise and effective blowing, very similar to the violent action of water flowing from the drainage pipe. You can replace an open pipe with EXAIR air nozzles to achieve the same laminar flow.  Then you can reduce the noise level, and the amount of compressed air being used.  To get the most out of your compressed air system, the EXAIR Super Air Knives and Super Air Nozzles are the products to use.   contact our Application Engineers now to discuss the amount of noise reduction and cost savings you can achieve by using EXAIR products.

 

 

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: twitter.com/exair_jb

Big TV’s and Big Compressed Air Savings

My great big TV bit the dust recently. It was a 65” rear projection, high definition…quite an upgrade over the 32” tube set that it replaced, a decade ago. One thing I remember from the day I bought it: the seller said to me as we were loading it up, “A warning: you’ll never be able to watch anything smaller.” The other thing I remember from that day was getting it back to the house and set up before my wife got home. She walked in, looked at its huge awesomeness in our modestly sized living room and said, “That’s almost embarrassing!” To which I replied, “I KNOW!!!”  Now, it WAS a little big for the room, but we acclimated quickly.

Until last month, when the display started to malfunction. I looked it up, and it was a fatal flaw: the parts would cost almost as much as a new 65” flat screen. Which we’re saving our money for…for now, though, we’re “getting by” with a 42” plasma TV that we “repurposed” from the back room. And the seller’s warning proved mostly true, although I’ve almost adjusted to the smaller screen. First world problems; I know.

One benefit of the smaller screen and advanced technology (plasma vs. those three big light bulbs in the rear projection) was decreased operating cost. Turns out, the 42” plasma uses less than 1/3 the power of the 65” rear projection (91 Watts vs. 283 Watts, respectively.) When my next electric bill comes, I’m wondering if I’m going to be pleased with the reduction, or if it’s going to put into perspective just how much TV I really watch. Stay tuned for more on that…

I recently had the pleasure of helping a customer realize a similar “a-ha” moment, with the amount of compressed air they were using throughout their plant. They were running (40) production machines, turning out custom plastic parts. Each machine had a ¼” crimped-end copper tube, which blows off the part as it’s being machined.

Each of the crimped copper lines uses approximately 30 SCFM when supplied at 80psig. These are being replaced with our Model 1100 Super Air Nozzles. They were able to quickly and easily adapt these by simply cutting off the crimped end, and installing a compression adapter fitting:

EXAIR Model 1100 Super Air Nozzle installs easily on copper lines, with a simple compression adapter.

EXAIR Model 1100 Super Air Nozzle installs easily on copper lines, with a simple compression adapter.

The Super Air Nozzle consumes just 14 SCFM @80psig, so we should be looking at around a 50% reduction in their compressed air usage in the operation, across their (40) machines. While all the data is still not compiled to determine their actual savings, the noise reduction alone has made a noticeable difference in the plant, which they’re getting used to a LOT quicker (and more agreeably) than I am to the smaller TV screen. But enough about that…I’ll be all right; really.

So that’s two of us, waiting for the next electric bill to see just how happy we can be with our energy savings. I don’t know what they’re going to do with their savings, but mine’s going into the 65” (energy efficient) TV fund.

Russ Bowman
Application Engineer
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Taking Professional Advice

I have an old house, turn of the last century, plaster and lath walls, remnants of knob and tube wiring, blocked over fireplaces in every room – old! Wiring in houses this old can be brittle which can make installing new ceiling fans tricky. First the ceiling is ten feet so you may be high on the ladder, and every time you need something from below you have to get a helper, carry a tool belt or climb down the ladder. Now if you are an experienced electrician, you have a tool belt filled with exactly what you need and a little extra. Cooks call this Mise en Place. My old man called it having your stuff together.

I don’t do it very well, so I have to climb down the ladder often. I tried to get a helper, but my nine month old son had trouble differentiating between a flat head screw driver and chew toy and wire nuts are clearly a choking hazard. Speaking of wire nuts. They seem to be such an innocuous widget. A wire nut is a wire nut. I have never thought much about them. Well it turns out that after the brittle wire has broken inside the wall. And then you drop the fifteenth wire nut, because it wouldn’t grab your old brittle wire. You spend some time thinking about the wire nuts as you are writing the check to the electrician. He might recommend an expensive brand of wire nuts that he uses that work great in these old houses. He gave me about twenty extra for my next attempt at electrical work, so I have a start on my electrical Mise en Place, but the next problem will probably involve plumbing…

Ceiling fan

Not my house, but similar.

Wire nuts remind me of air nozzles to some degree. They are such simple products but provide tremendous protection, and utility. There is also an incredible amount of brands, styles, and sizes. It is easy to think that the nozzle that comes installed on the thumb gun works great for home use, why should you spend time or money in investing in an upgrade. For the professional electrician, the expensive wire nuts made his day easier, more productive and his final installation safe. If you need to use compressed air to clean, dry or cool your parts, investing in an intelligent compressed air product will make the application quieter, more efficient and more effective.

Nozzle Lineup

EXAIR Engineered Solutions

EXAIR Super Air Nozzles are engineered solutions that meet OSHA requirements for dead end pressure – this makes them safe. The air nozzles utilize the Coanda effect to amplify compressed air flow up to 25 times – this makes them more effective. The small orifices build up pressure inside the supply the line in order to produce higher velocities – this makes the engineered air nozzles more efficient. Stop using cheap inefficient nozzles, think about your tools, and use what the professionals use.

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com

 

Ceiling Fan Photo Courtesy of Kevin GalensCreative Commons License

Compressed Air Noise Problem? Solve it With EXAIR Products

There is a new way to clean golf shoes!  That is with an EXAIR Safety Air Gun to blow the grass off their cleats and shoes.  In keeping with “new and better” methods, a golf course decided to purchase an air compressor, hose, and an air gun at the local hardware store.  They mounted the compressor inside a room to keep the noise levels low.  They put the air hose and air gun outside near the club house entrance for patrons to clean their spikes and shoes.

Problem: With most golf courses, they have the 9th and 18th greens near the club house.  They started to get complaints about the noise that was being generated by the compressed air gun, especially when the golfers on the green were ready to putt.

Solution: The golf course contacted EXAIR because they saw that we were experts in the field of compressed air products with noise, safety and efficiency.  I suggested the 1409SS Precision Safety Air Gun with chip shield.  With our engineered air nozzles and Precision Safety Air Gun, we were able to reduce the noise level to 68 dBA.  This is similar to a normal conversation at 3 feet (1 meter) away.  Also with the chip shield, it will help contain the grass and mud, and help attenuate the noise level even lower.  With the added features in saving compressed air, safety for dead end pressure, and localized hard hitting force, the golf course was excited to replace their current air gun.

Precision Safety Air Gun

Precision Safety Air Gun

When people go and purchase an air gun to use in their garage, shop, or even the golf course, one important factor that is overlooked is the air nozzle.  No matter how good the air gun is manufactured, the nozzle can make the air gun extremely loud and inefficient.  Just like a top-of-the-line paint gun, if the spray nozzle spits and sputters, you will never get a nice paint job.  The same goes with air guns.  EXAIR offers Safety Air Guns with engineered Super Air Nozzles to create the best combination for compressed air usage, i.e. low noise levels, safety, hard hitting force, and increased efficiency.  If you would like to discuss the features and benefits of the EXAIR Safety Air Guns and the Super Air Nozzles, you can contact our Application Engineers at 1-800-903-9247.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Friction Measurement

I had a customer wanting to reject a container off a conveyor belt.  The container held fruit, and when an optic detected a reject, they wanted to operate a solenoid to have a nozzle blow the container into the reject bin.  They had a range of containers that went from 6 oz. (170 grams) to 5 lbs (2,270 grams).  He wanted me to suggest one nozzle for all sizes, as they would automatically regulate the pressure for the full range of container sizes.  In looking at the largest size, this container will need the most force to remove.  The two factors that affects the force in this application is weight and friction.  When it comes to friction, it is generally an unknown for customers.  Here are a couple of things to help in determining the friction in your application.

Strawberry Delight

Strawberry Delight

Friction is a dimensionless number that represents the resistance created between two surfaces.  We have two types; static friction, ms, and kinetic friction, mk.  Static friction is the maximum amount of resistance before the object begins to slide.  Kinetic friction is the amount of resistance that is created when the object is sliding.  So, Static friction is always greater than kinetic friction, ms > mk.  For this application, we will have the air nozzle shoot horizontally to hit the target.  This is the most common and efficient way.

Let’s take a look our customer’s application.  We have a system to reject a non-conforming part with air.  The conveyor is a urethane belt.  The container is plastic.  We need to determine the correct nozzle to reject the 5 lb (2,270 gram) container.

Being that the conveyor belt is only 12” (30.5 cm) wide, we can determine that if we get the part moving, it will continue off the belt and into the reject bin.  The equation for the maximum amount of force required to move the container is Fs = ms * W(Equation 1).

Fs – Static Force – lbs (grams)

m– Static Friction

W – Weight lbs (grams)

One way to determine the amount of force is to use a spring scale.  The spring scale should have a maximum indicator to help tell you the maximum amount of force.  You will have to attach the scale to the container on the conveyor belt. Static friction is the resistance between two surfaces; so, you will have to use the same conditions as required for the operation.  Keep the scale parallel to the conveyor.  While slowly pulling on the scale, watch the dial.  Once the part begins to move, record the weight.  For the exercise above, it showed 1.82 lbs (826 grams) of force to move the 5 lb (2,270 gram) object.

Another way would be to determine the static friction, ms.  Static friction can be found by the angle at which an object starts to move.  By placing the container on a section of supported urethane conveyor belt and lifting one end of the conveyor belt until the object starts to slide, you can measure the angle or the height of the lift.  As an example, we take 3 foot (0.9 meter) of supported urethane conveyor belt and we lifted one end to a height of 1 foot (0.3 meters) before the 5 lb (2,270 gram) container moved.  To determine static friction, it is the tangent of the angle that you lifted, ms = tan(B) (Equation 2 below).  In this example, B = 20o.  Therefore Equation 2 gives us, ms = tan(20o) = 0.364.  If we plug this into Equation 1, we get the following:

Imperial Units                                                    SI Units

Fs = ms * W                                                         Fs = ms * W

= 0.364 * 5 lbs                                                    = 0.364 * 2,270 grams

= 1.82 lbs of force                                               = 826 grams of force
Now that we have the static force, we want to be slightly higher than that.  In looking at the force requirements that are in the EXAIR catalog, it shows that a model 1104 nozzle has a 1.9 lb (850 grams) of force.  This is at a 12” (30.5 cm) distance with a pressure of 80 psig (5.5 bar).  This nozzle will be able to slide the largest containers into a reject bin. With pressure manipulation, the customer can also use this same nozzle for the smaller containers.  If you have any applications that need products to be moved, you can always contact the application engineers at EXAIR to help you with a solution.

Variety of Nozzles

Variety of Nozzles

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

 

Image courtesy of Chobist, Creative Commons License

Force And Flow…Which One Is The Right Tool For The Job?

If you’re even a casual, occasional reader of the EXAIR Blog, you know we write an awful lot about efficiency…namely, the ability of engineered products to conserve compressed air, while optimizing its effectiveness. Oftentimes, these blogs are inspired by a conversation we’ve had with a user of simple and inexpensive (but wasteful and unsafe) blow off devices, such as open-end tubing, or drilled pipes. The first thing the caller wants to talk about is the force produced by one of our products…will it be the same as what’s being currently used?

The quick answer is no. In fact, if you’re looking for maximum force, there’s no better way to get it than simply blowing compressed air out the end of an open pipe. This has to do with nothing more complicated that grade school science – converting the potential energy (due to the compression of the air) to kinetic energy (what happens when it’s put into motion.) See, with an open-end blow off, almost all of the potential energy is converted to force. Plain old brute force. And it works GREAT for blowing stuff around…the larger the opening, and the higher the supply pressure; the more air will flow, and faster. Thing is, to produce a good blow off, you don’t need maximum force.

EXAIR’s Intelligent Compressed Air Products are engineered to use some of that potential energy of the compressed air to entrain large amounts of “free” air from the surrounding environment. That’s the purpose of the jets recessed between the fins of our Super Air Nozzles, and the Coanda profile of our Air Knives, Air Wipes, & Air Amplifiers.

EXAIR Intelligent Compressed Air Products such as (left to right) the Air Wipe, Super Air Knife, Super Air Nozzle, and Air Amplifier are engineered to entrain enormous amounts of air from the surrounding environment.

EXAIR Intelligent Compressed Air Products such as (left to right) the Air Wipe, Super Air Knife, Super Air Nozzle, and Air Amplifier are engineered to entrain enormous amounts of air from the surrounding environment.

These designs reduce the amount of compressed air that is used, which reduces the load on your air compressor, which makes everyone happy (OK, maybe not that happy, but pretty happy still.) They also mean that your blow offs will be quieter, and safer.

Perhaps your application calls for higher force. If that’s the case, EXAIR’s Air Knives, Air Amplifiers, and Air Wipes can be fitted with thicker shims for additional flow and force. So can our Flat Super Air Nozzles. And our largest High Force Super Air Nozzles are capable of generating up to 23lbs (10.4KG) of force.

Perhaps, though, your application calls for the highest force that can only be achieved with an open-end blow off. If that’s the case, you can still meet OSHA compliance through the use of extra protective equipment, pressure relief valves, guarding devices, etc. But the costs of those measures can make the cost of engineered products pale in comparison, so I highly recommend you make sure of what you need.

If we can be of any assistance with that, give us a call.  We can discuss your application, and get you the right tool for the job.

Russ Bowman
Application Engineer
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