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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Using Water and Air to Clean or Cool Cylindrical Parts

In the last year EXAIR has released two products that aid in cleaning and cooling cylindrical shapes. The liquid sprayed from our AT1010SS Internal Mix Spray Nozzle creates a 360° Hollow Circular Pattern that is excellent for cleaning the inner diameter of a pipe, a casting, or a bore. The 1006SS Back Blow Nozzle is an air only nozzle that is designed to clean, dry or cool the inside diameter of a hose or tube and also effective cleaning out channel. These products can be used in conjunction to create a more powerful system than either component by itself.

360 degree Internal Mix Hollow Circular Pattern

AT1010SS – 360° Internal Mix Hollow Circular Pattern

The AT1010SS spray nozzle can be used in a variety of applications. As I mentioned above the 360° spray pattern is great for spraying out the inside of a pipe or duct-work. In addition to these applications, the nozzle can be used to cover a wide area with spray patterns up to 53 inches in diameter. This wide spray area can be used for humidification, dust suppression, cooling or sanitizing. The 303 stainless steel construction of the nozzle will hold up to a variety of chemicals and environments.  These nozzles can cover a significant area while using a relatively small amount of air and liquid. The AT2010SS is also available which features EXAIR’s No Drip design (patent pending), which will positively shut off the liquid flow when air pressure is removed. This eliminates unwanted drips which can ruin surfaces and waste expensive liquids. The 360° Circular Hollow spray pattern is a versatile nozzle that covers a variety of applications.

The EXAIR Model 1006SS - Back Blow Nozzle

The EXAIR Model 1006SS – Back Blow Nozzle

The 1006SS back blow nozzle features a number of orifices around the outside of the nozzle which force air back toward the operator and away from the air inlet. In most applications this will be used to pull water, chips, coolant, or debris out of the end of a pipe, channel, or tubing to clean the inner diameter. The Back Nozzles will typically be offered with a chip shield to contain any chips or debris from blowing towards the operator.

These two nozzles used in conjunction would work great to cool, clean, and dry the inside of, say, a welded pipe. The AT1010SS could be used to flush the inside of the pipe with water to cool the weld and blow out and weld slag or grinding dust from preparing the area. The 1006SS could pull out the water or debris from the inside of the pipe. The AT1010SS can be reinserted to spray the inside of the pipe with a rust inhibitor to maintain the quality of the weld until installation.  These nozzles work well together to clean the ID of the channel, tube or hose in your application.

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com

EXAIR’s Free Efficiency Lab – How Much Money Can It Save You?

In many of my blogs, I talk about specific products benefits or applications, but this week I want to talk about a service that EXAIR provides to our customers: Efficiency Labs. The Efficiency Lab is comprehensive study of your current blow off. You can ship your current blow off to our facility. We can test it with our calibrated equipment and record your current product characteristics. Our most popular efficiency lab is testing home made blow offs. These are blow offs made from copper tubes, thumb guns with nozzles removed, or drilled pipe. These blow offs can get the job done, but they are noisy, wasteful and dangerous. Every compressed air expert knows that these blow offs need replaced, but sometimes it may difficult to decide which nozzle to use. By sending us your current blow off product(s) we can measure the force, flow, and noise of the blow off and provide a comprehensive report. This report, in most cases, compares your current setup against what EXAIR we would recommend to save compressed air, lower noise levels and maintain performance.

 In addition to providing a blow off suggestion, EXAIR’s efficiency lab can identify your energy cost for these blow offs. The standard industrial cost for compressed air is $0.25 per 1000 standard cubic feet. At first glance that might not seem like much, but it can add up. This week I did an efficiency lab for a customer that used 1/4 ID copper tube as their home made blow off.

open copper tube

This 1/4″ Open Blow off uses 30.8 SCFM of compressed air.

This small open tube ran continuously for 10 hours per day five days a week. To run this tube, cost a company $1,175 per year. The tube would flow 30.8 SCFM of compressed air when fed with 80 PSIG. By installing an EXAIR Super Air Nozzle,  part number 1100, the company could save 16.8 SCFM of compressed air and $650 per year. Once again $650 may not seem like much, but they used up to (40) of these open blow offs depending on what part they ran. Replacing all (40) of these blow offs saves $26,000 per year at a capital investment of $2,880 for (40) 1100-9212, Super Air Nozzle with 12 inch stay set hose. That would be a simple ROI of 72 days.  That ROI is only taking into account compressed air cost. Additionally, the 1100 Super Air Nozzle will reduce noise by 28 dBA and it complies with OSHA Standard CFR 1910.242(b) for dead end pressure.

We have found that our customers all have unique setups which greatly vary the values of their particular blow off. Even if customers have the same 1/4″ tube, the way they implement it can greatly affect its performance. Variations in inlet pressure, length, diameter tolerance and even what they used to cut it to length can have an impact on how much air it will consume. If you want to know for certain how much air and money you can save, use our free Efficiency Lab service.

EXAIR can save a lot for you!

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com

Calculating Force and Pressure For Air Nozzles

I assisted with an application where logs were being shaved to make thin laminate.  Because the logs were non-concentric or entirely smooth, the beginning of the sheet was riddled with scrapes and defects until it was about 8 foot (2.4 meters) long.  This was a very quick process, and once good product was coming from a shaved log, the machine would divert the material from the scrap bin to the production feed line with a nip roll.  At the speeds that the material was traveling, they needed to kept pressure on the leading edge of the sheet so that it would not “curl” up before the nip roll closed and grabbed the sheet. The drive rolls were pushing the laminate product toward the nip roll and they needed to keep the curl pushed flat along a plate and wondered if we had a product that could accomplish this.

We suggested a series of 2” flat air nozzles, model 1122, to keep the product pressed down on the plate with the force from the airflow.  In their trial runs, they tried to find the correct amount of air pressure to keep the product flat.  Once they found the pressure required, they noticed that the thin and delicate laminate was getting damaged.  Of course, it was just at the beginning length when it was being held in place as it slid into the nip roll, approximately 3 feet (0.9 meters).  Like any company, they did not want to waste any more product and wondered if we had anything else that we could recommend.

Thus a question was presented, and a solution was needed.  In thinking about this, it took me to my Michigan days where snow was abundant.  When walking on snow, you would fall through, but if you had snow shoes, you could stay on top of the snow.  This brought me to the factors of Pressure and Force.  Like with the laminate, if a smaller area does damage to the product (boots through the snow), can we expand the area to keep it from being damaged (snow shoes on top of the snow).

Snow Shoes

Snow Shoes

With the application, we needed to apply the same force on the material.  The equation for force is F = P *A (Equation 1), where F – Force, P – Pressure, and A – Area.

We can do an equality statement from Equation 1 which shows F = P1 * A1 = P2 * A2 (Equation 2).  The amount of pressure required from other EXAIR products can be determined, i.e. if I can double the surface area, then I can reduce the pressure by ½.  For model 1122, we can determine the pressure that was generated from Equation 1 and from the catalog data:

Imperial Units of Model 1122                                                      S.I. Units of Model 1122

F = 1.4 lbf (catalog)                                                                       F = 0.624 Kg (catalog)

A1 = Length X Width                                                                    A1 = Length X Width

= 5 inches X 2 inches (catalog)                                                   = 12.7 cm X 5.1 cm (catalog)

= 10 in^2                                                                                         = 64.8 cm^2

P1 = F/A1 (Rearranging Equation 1)                                         P1 = F/A1 (Rearranging Equation 1)

= 1.4 lbf/10 in^2                                                                            = 0.624 Kg/64.8 cm^2

= 0.14 PSI (pounds per in^2)                                                     = 0.0096 Kg/cm^2

Super Air Amplifier

Super Air Amplifier

Now that we have all the information from model 1122, we can determine the pressure required for a different product to keep the force the same.  With the 2” Super Air Amplifier, model 120022, it has a much larger footprint than the 2” flat air nozzle, model 1122.  So, with Equation 2, we can determine the amount of pressure required.  We will use model 1122 for our P1 and A1, and we will use model 120022 for P2 and A2.  From the catalog data for model 120022, we get a target area as follows:

 

Imperial Units for Model 120022                                               S.I. Units for Model 120022

A2 = pi * (diameter/2)^2                                                              A2 = pi * (diameter/2)^2

= 3.14 * (5.15 in/2)^2                                                                    = 3.14 * (13.1 cm/2)^2

= 20.8 in^2                                                                                      = 134.7 cm^2

 

When we apply the information to Equation 2, we get the following information:

 

Imperial Units                                                                                  S.I. Units

P2 = P1 * A1 / A2                                                                              P2 = P1 * A1 / A2

=(0.14 PSI * 10 in^2) / 20.8 In^2                                               =(0.0096 Kg/cm^2 * 64.8cm^2) / 134.7 cm^2

= 0.067 PSI                                                                                       =0.0046 Kg/cm^2

 

Now that the area was increased like the snow shoes above, the pressure was reduced and no additional waste was incurred.  Sometimes you have to think outside the igloo.  As with any application or product, you can always contact us at EXAIR for help.

 

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

 

Image courtesy of VasenkaPhotography. Creative Comment License

One Air Nozzle Saves $960 per Year – How Many Nozzles Could You Use?

A cardboard manufacturing facility was using a 3/8” outside diameter (OD) open tube to blow scrap cardboard off a conveyor. This scrap cardboard would occasionally be blown inside the roller area at the end of a conveyor creating a maintenance nightmare that required hours to disassemble and remove. To prevent this from occurring they installed another 3/8″ OD open compressed air tube to divert any cardboard headed toward the conveyor roller. The 3/8″ open tubing eliminated the scrap problem, but introduced a few new ones. The open hose is extremely noisy over (100 dBA). It does not comply with OSHA standard CFR 1910.242(b), which requires that a compressed air blow off device may not be dead ended at more than 30 PSIG. The most costly problem though is a 3/8″ open tubing uses a tremendous amount of compressed air.

They were using so much air in the facility that they were draining the system pressure in their facility. Obviously, they were going to replace the open tube with EXAIR 2” Flat Super Air Nozzle. Replacing this open blow off with an intelligent compressed air product, like the HP1125 High Powered Flat Super Air Nozzle or the 1104 Super Air Nozzle, would lower the noise level below 83 dBA. Also, those nozzles use significantly less air. They decided to use the model HP1125 for its thin profile to fit into the tight location. The only question was how much air and energy cost would they save. They could have easily installed a Digital Flow Meter on the supply pipe of the open tube to measure the change in flow once the EXAIR nozzle had been installed, but they wanted to try and estimate the air usage.

Using EXAIR’s test data, we know a 3/8″ OD open tube that is 18″ long will flow 68.5 SCFM at 80 PSIG. An HP1125 2″ Flat Super Air Nozzle utilizes 37 SCFM when fed with 80 PSIG inlet pressure. By removing one 3/8″ OD tube the cardboard manufacturer saved 31.5 SCFM of compressed air. With an electrical cost of $0.08 per kWh, compressed air costs $0.25 per 1000 SCF. Saving 31.5 SCFM reduces the manufacturers electrical bill by $0.48 every hour, $3.48 for every 8 hour shift, and $960 per year (250 working days, eight hours a day). If the manufacturer runs two shifts, the savings will double. The simple return on investment for this nozzle is 130 hours! How many projects can you measure a return on investment in hours?

2 Inch Flat

EXAIR’s 2 Inch High Power Flat Super Air Nozzle, HP1125

 

EXAIR intelligent compressed air products are easy to install, safe, and efficient. By installing these products instead of using unsafe open blow offs, your company can save thousands of dollar every year with minimal investment. While saving electrical expenses, we decrease the noise level which makes your production force a nicer place to work. We also comply with OSHA’s standards. Finally, we may be able to design the blow off better to consistently produce the quality product you expect. Call EXAIR today to discuss your application.

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com

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