Proper Supply Line Size And Fittings Provide Peak Performance

Many times when we provide the air consumption of an EXAIR product, we get a response like…. “I’ve got plenty of pressure, we run at around 100 PSIG”. While having the correct pressure available is important, it doesn’t make up for the volume requirement or SCFM (Standard Cubic Feet per Minute) needed to maintain that pressure. We commonly reference trying to supply water to a fire hose with a garden hose, it is the same principle, in regards to compressed air.

When looking to maintain an efficient compressed air system, it’s important that you use properly sized supply lines and fittings to  support the air demand (SCFM) of the point-of-use device. The smaller the ID and the longer the length of run, it becomes more difficult for the air to travel through the system. Undersized supply lines or piping can sometimes be the biggest culprit in a compressed air system as they can lead to severe pressure drops or the loss of pressure from the compressor to the end use product.

Take for example our 18″ Super Air Knife. A 18″ Super Air Knife will consume 52.2 SCFM at 80 PSIG. We recommend using 1/2″ Schedule 40 pipe up to 10′ or 3/4″ pipe up to 50′. The reason you need to increase the pipe size after 10′ of run is that 1/2″ pipe can flow close to 100 SCFM up to 10′ but for a 50′ length it can only flow 42 SCFM. On the other hand, 3/4″ pipe is able to flow 100 SCFM up to 50′ so this will allow you to carry the volume needed to the inlet of the knife, without losing pressure through the line.

Pipe size chart for the Super Air Knife

We also explain how performance can be negatively affected by improper plumbing in the following short video:

 

Another problem area is using restrictive fittings, like quick disconnects. While this may be useful with common everyday pneumatic tools, like an impact wrench or nail gun, they can severely limit the volumetric flow to a device requiring more air , like a longer length air knife.

1/4″ Quick Connect

For example, looking at the above 1/4″ quick disconnect, the ID of the fitting is much smaller than the NPT connection size. In this case, it is measuring close to .192″. If you were using a device like our Super Air Knife that features 1/4″ FNPT inlets, even though you are providing the correct thread size, the small inside diameter of the quick disconnect causes too much of a restriction for the volume (SCFM) required to properly support the knife, resulting in a pressure drop through the line, reducing the overall performance.

If you have any questions about compressed air applications or supply lines, please contact one of our application engineers for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

Getting A Little More Vacuum and Flow

Last week, a customer called and indicated that he was a long time user of the model 6013 High Velocity Air Jet.

6013

Model 6013 High Velocity Air Jet

The customer was using the Air Jet to remove light trim scrap from a manufacturing process. The Air Jets utilize the Coanda effect (wall attachment of a high velocity fluid) to produce air motion in their surroundings.  A small amount of compressed air to the Air Jet is throttled through an internal ring nozzle at speeds above sonic velocity.  In the above image, this produces a vacuum at the left side, pulling in large volumes of surrounding air. By utilizing this vacuum pull and ducting the right side exhaust, air and scrap stream to a collection area. The customer assembled a small, efficient, and inexpensive scrap removal system.

The reason the customer had called in was there were some recent changes to the manufacturing process and needed a bit more vacuum force and flow to handle larger scrap and longer travel. We explored using a larger shim, but they were already using the largest size (0.015″.) We talked about the other products that EXAIR offers (Air Amplifiers, Line Vacs) that are used for scrap removal and conveyance.  But with any change, there are usually other modifications and approvals that must be dealt with in order to proceed. So we hit upon the Adjustable Air Jet, which is an adjustable version of the model 6013.

6019

Model 6019 Adjustable Air Jet

The model 6019 Adjustable Air Jet utilizes an adjustable air gap in place of the fixed shim thickness.  This allows for greater air flow, which results in greater vacuum and conveyance distances. As is the case for many customers, we gathered some additional data to help this customer make a decision. We set up each of the units and tested them at maximum capabilities, and the model 6019 was shown to deliver upwards of 50% greater flow.  The customer felt certain this level of performance would handle what the changed process would require, and best of all, no modifications to any part of the set-up would be required, simply install the 6019 where the 6013 was currently placed.

The High Velocity Air Jet is also part of the model 1909 Blowoff Kit, and is also used in the model 8193 Ion Air Gun and model 8194 Ion Air Jet, for Static Elimination applications. Of course, each can be purchased as an individual item.

To discuss your application and how an EXAIR Intelligent Compressed Air Product can make your process better, feel free to contact EXAIR and myself or one of our other Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

Send me an email
Find us on the Web
Like us on Facebook
Twitter: @EXAIR_BB

 

Can Counting Carbs Help in Your Compressed Air System?

Breakfast Cereal

Breakfast Cereal

Have you ever counted the amount of carbs that you eat?  People typically do this to lose weight, to become healthier, or for medical reasons like diabetes.  Personally, I like to eat cereal in the morning.  I will pull a box of cereal down from the cupboard and look at the Total Carbs field.  One morning, I looked at a box of gluten-free rice flakes and compared it to a peanut butter nugget cereal.  I noticed that the carbs were very similar.  The rice cereal had 23 grams of total carbs while the peanut butter nuggets had only 22 grams of total carbs.  Then I looked at the serving size.  The rice cereal had a serving size of 1 cup while the nuggets only had a serving size of ¾ cups.  So, in comparison, for one cup of nugget cereal, the total amount of carbs was 27.5 grams.  Initially, I thought that they were similar, but the peanut butter nugget was actually 20% higher in carbs.  This same “misdirection” occurs in your compressed air system.

Here is what I mean. Some manufacturers like to use a lower pressure to rate their products.  This lower pressure makes it seem like their products will use less compressed air in your system.  But, like with the serving sizes, it can be deceiving.  It is not a lie that they are telling, but it is a bit of misconception.  To do an actual comparisons, we have to compare the flow rates at the same pressure (like comparing the carbohydrates at the same serving size).  For example, MfgA likes to rate their nozzles at a pressure of 72.5 PSIG.  EXAIR rates their nozzles at 80 PSIG as this is the most common pressure for point-of-use equipment.  You can see where I am going with this.

To compare nozzles of the same size, MfgA nozzle has a flow rate of 34 SCFM at 72.5 PSIG, and EXAIR model 1104 Super Air Nozzle has a rating of 35 SCFM at 80 psig. From an initial observation, it looks like MfgA has a lower flow rating.  To do the correct comparison, we have to adjust the flow rate to the same pressure.  This is done by multiplying the flow of MfgA nozzle by the ratio of absolute pressures.  (Absolute pressure is gage pressure plus 14.7 PSI).  The ratio of absolute pressures is:  (80PSIG + 14.7) / (72.5PSIG + 14.7) = 1.09.  Therefore; the flow rate at 80 PSIG for MfgA nozzle is now 34 SCFM * 1.09 = 37 SCFM.  Now we can compare the flow rates for each compressed air nozzle.  Like adjusting the serving size to 1 cup of cereal, the MfgA will use 9% more compressed air in your system than the EXAIR model 1104 Super Air Nozzle.  This may not seem like much, but over time it will add up.  And, there is no need to waste additional compressed air.

Family of Nozzles

Family of Nozzles

The EXAIR Super Air Nozzles are designed to entrain more ambient air than compressed air needed. This will save you on your pneumatic system, which in turn will save you money.  The other design features gives the EXAIR Super Air Nozzle more force, less noise, and still meet the OSHA compliance.

If you want to run a healthier compressed air system, it is important to evaluate the amount of compressed air that you are using. To do this correctly, you always want to compare the information at the same pressure.  By using the EXAIR Super Air Nozzles in your compressed air system, you will only have to worry about your own weight, not your pneumatic system.

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

 

Picture: Breakfast Cereal by Mike Mozart Creative Commons Attribution 2.0 Generic License

FREE TESTING!!!! EXAIR’s Award Winning Efficiency Lab Saves Air and Money

EXAIR’s Efficiency Lab is now the “award-winning Efficiency Lab”. Thank you to Environmental Protection Magazine for recognizing the value and importance of this EXAIR service.

epawinner2016_400x

 

I have blogged about this many times and we continue to help customers by using our free Efficiency Lab service that EXAIR provides to customers throughout the USA.  The EXAIR Efficiency Lab allows customers to send in their existing blow off device and we will test it for compressed air consumption, sound level, and force.  Ideally we try to take these measurements at the same operating pressure that is being supplied in the field so that we can compare it to an EXAIR product and offer the customer the best solution, the safest solution, and an engineered solution capable of saving them money through air savings and effectiveness.

Here is a recent example of  a product sent in by a customer concerned with compressed air consumption and safety of their people. The  hose they sent in was actually designed to be used with liquid coolants and was a very large consumer of compressed air.

A flexible blow off with .495" openings. Designed for liquid but used for compressed air. Enormous waste of air and a huge safety risk.

A flexible blow off with .495″ openings. Designed for liquid but used for compressed air. Enormous waste of air and a huge safety risk.

The hose shown above was being used at 40 psig inlet pressure.  The device is not OSHA compliant for dead end pressure, nor does it meet or exceed the OSHA standard for allowable noise level exposure.   The hose was utilizing 84.64 SCFM of compressed air and was giving off 100.1 dBA of sound.

OSHA Noise Level

As seen in the chart above, an employee is only permitted to work in the surrounding area for 2 hours a day when exposed to this noise level.   The amount of force that the nozzle gave off was far more than what was needed to blow chips and fines off the part.   The EXAIR solution was a model 1002-9230 – Safety air Nozzle w/ 30″ Stay Set Hose.

The EXAIR products were operated at line pressure of 80 psig which means they utilized 17 SCFM of compressed air and gave off a sound level of 80 dBA.  On top of saving over 67 SCFM per nozzle and reducing the noise level to below OSHA standard, the EXAIR engineered solution also meets or exceeds the OSHA standard for 30 psig dead end pressure.   In total this customer has replaced 8 of these inefficient lines and is saving 541 SCFM of compressed air each time they activate the part blowoff.

If you would like to find out more about the EXAIR Efficiency Lab, contact an Application Engineer.

We look forward to testing your blow off and being able to recommend a safe, efficient, engineered solution.

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

 

A Burst of Air From Our Super Air Nozzles Keeps Vacuum System Pipes Clean

Bales of cotton and polyester fibers

Bales of cotton and polyester fibers

An overseas textile company had many automated spinning machines to manufacture yarn from raw cotton and polyester fibers. They used a vacuum collection system to remove any floating fibers from within their spinning machines for safety reasons.  In this facility, they had three rows of ten spinning machines.  Above each row, a collection duct, ranging for 8” to 30” in diameter, would collect the fibers and transport them to a baghouse.  The difference in diameters was to keep the vacuum pressure the same in each spinning machine.  The machine that was the farthest from the baghouse had the smallest diameter pipe, and the machine that was closest to the vacuum system had the largest.  They needed to keep an optimum vacuum pressure inside each machine because too much would affect the production of the yarn and too little would allow the fibers to migrate into the production area.  The concern with fibers migrating in the production area was a fire hazard, a big safety issue.  In order to have each row of machines performing effectively, they needed to keep the static pressure as low as possible.

Blending Machine (Note: the spinning machines are behind this)

Blending Machine (Note: the spinning machines are behind this)

The issue that they had was the discarded fibers would gather and collect in the ductwork. Each machine had a 4” duct that would draw the fiber from the spinning machine into the bottom of the collection duct overhead.  The velocity profile inside the main line was being disrupted by each feed duct, as it allowed a “dead” spot for the fibers to gather.  As fibers would entangle with each other and become larger, the static pressure would increase.  This would cause the vacuum pressures to change inside the spinning machines, affecting production.  They would have to shut the row down, open the ductwork, and clean the entire piping system.  This was time consuming and costly as it stopped production.

The customer tried a homemade nozzle made of a copper tube. He flattened one end and placed it in the bottom of the ductwork just upstream of the problem area.  He triggered it intermittently, and after a while he noticed that he still had the fibers collecting in the pipes, but in different areas.  In knowing how the velocity profile is very sensitive in dust collection systems, any additional obstructions could cause the problem to change to another location within the system.  He contacted EXAIR to see if we could help him.

I put on my engineering hat to help solve this issue. I suggested our model 1104 Super Air Nozzles because it had enough force to reach the other side within the range of diameters.  The EXAIR Super Air Nozzles are very powerful and efficient nozzles.  It is designed to entrain the ambient air.  This gives it a powerful force without using a lot of compressed air.  My suggestion was to place them along the top of the collection pipe as we needed to keep the profile smooth along the bottom section of the pipe.  As a recommendation, I suggested for them to use an angled extraction port (not made by EXAIR).

Extraction Port (Not sold by EXAIR)

Extraction Port (Not sold by EXAIR)

It screws to the outside of the ductwork, and it has a 2” opening with a 45 degree angle (reference photo above).  They could aim the Super Air Nozzles at the “dead” spots to lift the fibers off the bottom; allowing the system to pull them toward the baghouse.  Without having to redo their entire collection system, they were able to cut an opening in the top of the duct and mount the Super Air Nozzles.  As an added benefit, the nozzles were not in the air stream; so, there was no additional static pressure in the system.  The customer was able to design a solenoid triggering system to have only one Super Air Nozzle to operate at one time.  It would start from the farthest point, and trigger one at a time toward the bag house.  With a short burst of air, it would keep the fibers in the air stream without affecting the operations of the spinning machines.  This customer was very happy as they were able to keep their operation running without a buildup of static pressure in the vacuum system and without allowing fibers to escape into the work area.

EXAIR Nozzles

EXAIR Nozzles

If you have contamination that gets stuck in your system, and you need a powerful burst of air to break it up, EXAIR may have the right nozzle for you. It can save you from much frustration, headaches, and waste of time in making your own blow off devices.

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

High Power Super Air Nozzles Provide Forceful Air Flow

When considering the application of a compressed air product, we have an awful lot of discussions with callers about the amount of force generated.  Now, if that’s all you want, you’re not going to get more force from compressed air flow from anything but an open ended blow off.  There are problems inherent with this: it’s unsafe, it’s loud, and it’s a horribly inefficient way to use compressed air.  By the time they’ve called EXAIR, they probably know this, but the main concern is still the same: solving their application.

Good news is, you don’t need a lot of FORCE for most blow off situations.  Think about it…how much do sawdust, machining chips, coolant droplets, etc., weigh, anyway?  All you really need to do is optimize the air flow, which is EXACTLY what EXAIR Intelligent Compressed Air Products are engineered & designed for.  So, we talk a LOT about how often a high amount of force isn’t needed in compressed air blowing applications.

Then…I got a call from a user who needed force.  They had an air knife installed to blow parts out of a mold, as the halves separated.  There’s a rectangular array of parts in a multi-cavity mold, and the air knife just wasn’t getting them all out, all the time.

The air knife, was, of course, originally chosen for its efficiency, but it just wasn’t delivering the needed “punch.” They even tried other shim thicknesses (which increases the outlet air gap) to increase the flow & force delivered, and that helped a little, but wasn’t 100% effective.

The solution came in the form of an array of HP1125-9212 2″ High Power Flat Super Air Nozzles, supplied with 12″ Stay Set Hoses.  They’re able to mount these closer to the mold than the air knife, and the ability for each nozzle to operate independently meant they were able to be aimed precisely where they can do the most good.  They are now able to evacuate the molds the first time, every time.

Sometimes, you DO need the high force of the HP1125 2″ High Power Flat Super Air Nozzle

If you have questions about how to get the most out of your compressed air use, give me a call.

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

Part Ejection Improved by Choosing the Right Air Nozzle

Recently, I was able to work with a gentlemen from a stamping company that produces small metal stamped lids for the cosmetic industry.  He was frustrated because the current blow off setup, a copper tube and nozzle (shown below), was too weak and narrow to be effective with parts ranging from 1″ to 2.5″ wide.  Whenever a lid did not get completely discharged, the machine would jam and double hit on the next cycle, ruining (2) parts in the process, not to mention, potentially damaging the the tooling.

blowoff

Stamping Operation with Original Nozzle

After reviewing the process, which is very high speed, we wanted a strong, concentrated blast of air that matched the part profile to maximize the air flow contact patch.  We agreed the model HP1125 – 2″ High Power Flat Super Air Nozzle would be a good nozzle to implement and test.  In addition to the Nozzle, the customer ordered the model HP1132SS Shim Set, to allow for flow and force adjustment of the nozzle to obtain the best possible performance under production conditions.  The HP1125 nozzle provides 2.2 lbs of force with the standard .025 patented shim installed, and can be decreased or increased by changing the shim to .020″ or .030″ thick. Preliminary testing has proven successful, and reliability testing and data collection is underway.

2 Inch Flat

2″ Flat Super Air Nozzle

EXAIR has available, the Air Nozzles Blowoff Guide, a handy reference with 23 pages of technical data for OSHA safe nozzles and Safety Air Guns for every application imaginable.

blowoff guide

The EXAIR Air Nozzles Blowoff Guide

To discuss your part ejection, blowoff, cooling or drying application, feel free to contact EXAIR and one our  Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

Send me an email
Find us on the Web
Like us on Facebook
Twitter: @EXAIR_BB

%d bloggers like this: