Calculating Static Friction To Eject Parts with Air

2″ Flat Super Air Nozzle

In today’s fast-paced world, companies are always looking for ways to do things faster, cheaper, more efficiently without sacrificing safety.

A cereal company had a high-speed system to check the quality of each box of cereal.  When a box did not meet the quality criteria for visual and/or weight, the box would be rejected.  The rejection system that they used was a quick blast of compressed air to remove the box from the conveyor line into a non-conforming bin.  For their first attempt, they tried to use a ¼” copper tube with a solenoid valve attached to a reservoir tank.  When a “bad” box was detected, the solenoid would be triggered, and compressed air would “shoot” the box off the rubber conveyor belt.  The ¼” copper tube can be an inexpensive, common, and easy-to-use device; but they found that the copper tube was very loud (above OSHA limits for noise exposure) and not very effective.  As a note, this company had a safety committee, and they wanted to keep all blowing devices below 80 dBA in this department.  The ¼” copper tube was around 100 dBA.  So, they contacted EXAIR to get our expertise on this type of application.

The cereal company gave me some additional details of the operation.  The box weighed 26 oz. (740 grams) with a dimension of 7.5″  wide by  11″ tall by  2 3/4″ deep (19 cm X 28 cm X 7 cm respectively).  The issue with the ¼” copper tube was the small target area compared to the area of the box.  With any slight variation in the timing sequence, the force would miss the center of mass of the box.  The box could then spin and remain on the conveyor belt.  This would cause stoppage and disruption in the system.  They asked if EXAIR had a better way to remove the defective boxes.

I recommended a model 1122, 2” Flat Super Air Nozzle.  The reason for this style of nozzle was for a variety of reasons.  First, we needed a larger area to “hit” the box.  This Flat Super Air Nozzle has a width of 2” versus the ¼” copper tube.  This increased the target area by 8 times.  So, any small variations in time, we could still hit the center of mass and remove the box.  The second reason was the force rating.  The model 1122 has a force of 22 oz. (624 grams) at 80 PSIG (5.5 bar).  This is slightly under the 26 oz. (740 grams) weight of the cereal box, but we are just sliding the box and not lifting it.  If we can overcome the static friction, then the box can be easily removed.  With Equation 1, we can calculate the required force.

Equation 1:

Fs = ms * W

Fs – Static Force (grams)

m– Static Friction

W – Weight (grams)

From the “Engineering Toolbox”, the static friction between rubber and cardboard is between 0.5 to 0.8.  If I take the worse case condition, I can calculate the static force between the belt and cereal box using Equation 1:

Fs = 0.8 * 740 grams

Fs = 592 grams

The model 1122 has a force of 22 oz. (624 grams), so plenty enough force to move the box from the rubber conveyor belt.

The third reason for this nozzle is the noise level.  The noise level of the model 1122 is 77 dBA, well below the safety requirement for this company.  Noise levels are very important in industries to protect operators from hearing loss, and the model 1122 was able to easily meet that requirement.  I added an additional reason for recommending the 2” Flat Super Air Nozzle; compressed air savings.  Companies sometimes overlook the cost when using compressed air for blow-off devices.  In this comparison, the ¼” copper tube will use 33 SCFM (934 SLPM) at 80 PSIG (5.5 bar) while the model 1122 will only use 21.8 SCFM (622 SLPM).  This is a 33% reduction in compressed air; saving them money.

At the intro, I mentioned that companies are looking to do things faster, cheaper, more effective without sacrificing safety.  For this company, we were able to increase production rates by removing every cereal box from the conveyor belt.  We also saved them money by reducing the compressed air requirement as well as keeping it safe by reducing noise.

If you have an application that needs products to be moved by air, you can contact an Application Engineer at EXAIR to help you with a solution.

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

General Good Ideas For The Compressor Room

When considering your compressor room all too often the phrase applies “out of sight and out of mind”.  Of course, we all know that is not a good approach to the compressor room or really anything in life.  Unfortunately, many of us take for granted that very system that delivers the power to keep our machines, equipment and tools operating.

Air Compressor
Compressor Room Located Outdoors

So, what can we do keep the ‘lungs” of our plants performing reliably and efficiently?  Since this Blog is about “General Good Ideas For The Compressor Room”, I have some points below for your consideration.

  • Ideally the compressor room should be centrally located to minimize the length of the pipes and allows for easier noise control. With long piping runs leaks become more likely and frictional losses are increased.
  • The compressor room should be sized to allow for easy maintenance and future expansion.
  • For efficient operation air compressors need clean intake air. Intake air that is dusty, dirty or contains gaseous contamination will reduce the efficiency and possibly the longevity of your equipment.
  • The compressor room needs adequate ventilation since air compressors generate significant heat. If excessive heat is allowed to build up it reduces the efficiency of the air compressor raising utility costs, causes compressor lubricant to break down prematurely that could possibly result in increased maintenance and compressor failure.
  • What is the velocity of the air through the main headers? If the speed is above 1200 FPM many dryers have reduced efficiency and speeds greater than this can also carry moisture past the drainage drop legs.
  • Excess friction caused by too small of a diameter piping creates pressure loss, which reduces efficiency and if the compressor is ran above its pressure rating to overcome the frictional losses increases energy consumption, maintenance costs and down time.

Now that your compressor room is shipshape in Bristol fashion, you might think that all is well.  While that may be true, chances are there are other significant additional savings to be had.  EXAIR specializes in point of use compressed air products that are highly efficient and quiet!  If you have any blow-offs that are open tube or howl as loud as the ghost of Christmas yet to come, check out EXAIR’s Super Air Nozzles.  They are highly efficient and quiet, in fact they meet OSHA Standard 29 CFR – 1941.95 for maximum allowable noise and OSHA Standard 29 CFR 1910.242 (b) for higher than 30 PSIG blow-off pressure.  All of EXAIR’s compressed air products are engineered to minimize compressed air consumption and take advantage of the Coanda effect.  Simply stated EXAIR’s highly engineered, intelligent designs entrain (combine) ambient air with the compressed air supply which saves you money!

nozzle_anim_twit800x320
EXAIR Super Air Nozzle entrainment

EXAIR also offers the Ultra Sonic Leak Detector.  Simply point the device at a suspected leak which are typically found at unions, pipes, valves and fittings from up to 20’ away.   Plants that are not maintaining their plumbing can waste up to 30% of their compressors output through undetected leaks.

ultrasonic_2
EXAIR Ultra Sonic Leak Detector

EXAIR has a complete optimization product line that the Ultra Sonic Leak Detector is in that includes the Electronic Flow Control, Digital Flowmeter’s and a Digital Sound Level Meter.  All designed to either increase the safety or efficiency of your compressed air usage.

EXAIR has 15 other product lines all designed to increase your process efficiency and save you money by using you compressed air supply efficiently.  Why not visit the EXAIR website or call and request a free catalog?

When you are looking for expert advice on safe, quiet and efficient point of use compressed air products give us a call.   We would enjoy hearing from you!

Steve Harrison
Application Engineer
Send me an email
Find us on the Web 
Follow me on Twitte
Like us on Facebook

 

Image taken from the Best Practices for Compressed Air Systems Handbook, 2nd Edition

Super Air Nozzles and Stay Set Hoses to Replace Open Tubes

I recently worked with an company that performs energy audits and they were working with a food company to review and propose ways to reduce the energy consumption throughout the plant. One area where we were able to help was on an onion peeling machine, shown below:

Vegetable Peeler Wide
Onion Peeler With Screw Conveyor and Blow off Tubes

The area of machine in question used a screw conveyor and friction source to help loosen the peels and fifteen (15) 1/4″ O.D. open ended tubes, which were noisy and unsafe, to blow the peels completely off and away form the onion. The auditor was able to install an air flow meter on the system and found that the machine was consuming 220 SCFM of compressed air for this operation.

Vegetable Peeler Detail
(15) Total, 1/4″ Tubes Used to Blow Air and Help Remove the Peels

We proposed to replace the tubes with a 6″ Stay Set Hose and the model 1103 Mini Super Air Nozzle.  Each model 1103 Mini Super Air Nozzle will consume just 10 SCFM of 80 PSIG compressed air. Attached to the 6″ Stay Set Hose, the nozzle can be placed exactly where needed and aimed appropriately. A strong blast of air rated at 0.56 lbs (9 ozs.), and ultra quiet at 71 dBA, the Mini Super Air Nozzle delivers the results needed.

1103-e1543953915424.jpg
Model 1103 – Mini Super Air Nozzle

1103 Performance

1103 Pattern

9256
Model 9256 6″ Stay Set Hose

The Stay Set Hose has “memory” and will not creep or bend, simply install the 1/4 NPT fitting into the compressed air supply side, an thread the 1/8 NPT Mini Super Air Nozzle into the other end and position as needed!

Fifteen (15) of the Mini Super Air Nozzles will pass 150 SCFM of compressed air compared to the current usage of 220 SCFM, resulting in a 70 SCFM drop, or a 31.8 % reduction.  At a typical cost of $0.25 per 1000 Cubic Feet of Compressed Air, the nozzles would save $1.05 per hour of operation. Rate of Return yields a full pay-off in just 43 days of operation (24 hours per day operation)!

If you are looking for ways to save on compressed air usage in your facility that is safe to operate and quiet to use, we will have a solution for you.

If you have questions about any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of 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

 

Back Blow Nozzles Clean Inside Metal Tubes

A manufacturing plant EXAIR worked with made cast aluminum tubes for the automotive industry.  After the parts were cast, a machining operation would clean the ends.  This left coolant and metal shavings inside the tube.  Before going to assembly, they had to clean the part.  They created a two-tube fixture (reference picture above) to fit the 25mm tubes in place.

Two home-made nozzles were used to fit inside the tubes to blow compressed air.  The nozzles were attached to the ends of two 17mm pipes which supplied the compressed air.  A cylinder was used to push the nozzles from the top of the aluminum tube to the bottom then back up again.  The liquid emulsion and debris would be pushed downward into a collection drum.  When they started operating their system, the inside of the tubes still had contamination inside.  They wanted to improve their process, so they looked for an expert in nozzle designs, EXAIR.

Back Blow Air Nozzle Family

EXAIR designed and manufactures a nozzle for just this type of operation, the Back Blow Air Nozzles.  We offer three different sizes to fit inside a wide variety of diameters from ¼” (6.3mm) to 16” (406mm).  They are designed to clean tubing, pipes, hoses, and channels.  The 360o rear airflow pattern can “wipe” the entire internal surface from coolant, chips, and debris.  For the application above, I recommended the model 1006SS Back Blow Air Nozzle.  This 316SS robust design would fit inside the tubes above.  The range for this Back Blow Air Nozzle is from 7/8” (22mm) to 4” (102mm) diameters.  The customer did have to modify the function of the equipment by placing the cylinder and the rods under the aluminum tubes.  The reverse airflow would still push the contamination into the collection drum that was placed underneath the tubes.

After installing the model 1006SS onto the rods, the cleaning operation became more efficient.  Not only was the entire internal diameter getting clean, they were able to turn off the compressed air until they reached the top of the tube.  With the model 1006SS, they only needed one pass to clean.  This cut the air consumption in half, saving them much money by using less compressed air.  In addition, they were able to speed up their operation by 20%.  Cleaner tubes, less time, cost savings; they were happy that they contacted EXAIR for our expertise.

Reverse Air Flow

If you need to clean the inside of tubes, hoses, pipes, etc., EXAIR has the perfect nozzle for you, the Back Blow Air Nozzles.  EXAIR can also offer these nozzles on our VariBlast, Soft Grip and Heavy Duty Air Guns for manual operations.  They come with Chip Shields and extensions that can reach as far as 72” (1829mm).  Or like the customer above, automate the system to get a great non-contact cleaning.

If you require any more details, you can contact an Application Engineer at EXAIR.  We will be happy to help.

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

How to Calculate SCFM (Volume) When Operating at Any Pressure

If you need to operate at a different pressure because you require less or more force or simply operate at a different line pressure, this formula will allow you to determine the volume of air being consumed by any device.

Volume Formula

Using the EXAIR 1100 Super Air Nozzle as our example:

1100

Lets first consider the volume of the 1100 Super Air Nozzle at a higher than published pressure.  As shown in the formula and calculations it is simply the ratio of gauge pressure + atmospheric divided by the published pressure + atmospheric and then multiply the dividend by the published volume.  So as we do the math we solve for 17.69 SCFM @ 105 PSIG from a device that was  shown consume 14 SCFM @ 80 PSIG.

higher

Now lets consider the volume at a lower than published pressure.  As shown it is simply the ratio of gauge pressure + atmospheric divided by the published pressure + atmospheric and then multiply the dividend by the published volume.  So as we do the math we solve for 11.04 SCFM @ 60 PSIG from a device that was shown to consume 14 SCFM @ 80 PSIG.

lower

When you are looking for expert advice on safe, quiet and efficient point of use compressed air products give us a call.  Experience the EXAIR difference first hand and receive the great customer service, products and attention you deserve!  We would enjoy hearing from you.

Steve Harrison
Application Engineer
Send me an email
Find us on the Web 
Follow me on Twitter
Like us on Facebook

Experience The EXAIR Difference For Yourself!

The other day I received a call from the Corporate Director of a manufacturing company with multiple locations across the country.  He had grown frustrated with the service and quality he was receiving from his current Air Gun & Nozzle supplier.  He explained that he was unable to buy the individual components to make repairs to the air guns and described the overall quality as “disposable”.

I asked him for model air gun he had been purchasing so that I could make an accurate comparison and recommendation for the equivalent or better EXAIR offering.  As I researched this competitive air gun I was surprised to find out that the specifications were vague at best.  What I mean by that is EXAIR clearly publishes air consumption @ 80 PSI, force which is specified @ 12″ from the nozzle and the sound level in dBA @ 3′ from the nozzle.

I recommended the EXAIR 1699-24 (1699-12 pictured) which is the VariBlast Compact Safety Air Gun, 24″ Extension Pipe & the 1102 Mini Super Air Nozzle.

Final Image
1699-12

The 1699-24 (supplied with the 1102 Mini Super Air Nozzle) specifications are: 10 SCFM @ 80 PSI compressed air consumption, 9 ounces force @ 12″ from nozzle and 71 dBA @ 3′ from the nozzle.  The 1102 1/8 FNPT is available in Zinc Aluminum, 316 SS or PEEK plastic.

1102 Mini Super Air Nozzle

The customer reported an average noise reduction of over 15 dBA which looks considerable, however it is a greater gain than the number would indicate. An increase of 10 dB is required before sound is perceived to be twice as loud, therefore EXAIR lowered the perceived sound by over 150%!

While this customer did not add the optional EXAIR Chip Shield you certainly can.  Simply add -CS to the end of any Safety Air Gun part number.  The part number for the featured VariBlast Safety Air Gun would become 1699-24-CS.  Chip Shields are made from durable poly-carbonate that protect operators from flying debris often associated with blowing chips off machined parts.  Chip Shields are also great for keeping coolant from spreading everywhere during drying operations.  They are available for the VariBlast Safety Air Gun, Soft Grip Safety Air Gun and Heavy Duty Safety Air Gun.  Also Chip Shields can be used on Safety Air Guns with or without the aluminum extension!

When you are looking for OSHA safe, quiet and efficient point of use compressed air products give us a call.  Experience the EXAIR difference first hand and receive the great customer service, products and attention you deserve!  We would enjoy hearing from you.

Steve Harrison
Application Engineer
Send me an email
Find us on the Web 
Follow me on Twitter
Like us on Facebook

 

Product Overview: Back Blow Safety Air Guns

BackBlowNozzle

EXAIR’s highly engineered and efficient Back Blow Nozzle’s provide a powerful 360° airflow through an array of holes to remove coolant, chips or debris.  Back Blow Nozzle’s are the perfect solution for cleaning out the inside of any pipe, tube, hose or channels.

They are available in three different sizes:

M4 X .5 BB Nozzle

.25 NPT BB

1 NPT BB

The Back Blow Nozzle’s are also offered on the VariBlast, Soft GripHeavy Duty, and Super Blast Safety Air Guns.  They can be configured with different length extensions (up to 72″) to make nearly any cleaning job within reach!   We recommend the optional Chip Shield since the air stream is carrying the debris back towards the operator.

1604SS-6-CS-lftangle
Variblast Safety Air Gun 1604SS-6-CS, Includes 1004SS Back Blow Nozzle With 6″ Extension and Chip Shield. The 1604SS Is Offered In 6″, 12″, 24″ and 36″ Lengths.

1204SS-6-CS
Soft Grip Safety Air Gun 1204SS-6-CS, Includes 1004SS Back Blow Nozzle With 6″ Extension and Chip Shield.  The 1204SS Is Offered In 6″, 12″, 24″ and 36″ Lengths.

1206SS-6-CS559
Soft Grip Safety Air Gun 1206SS-6-CS, Includes 1006SS Back Blow Nozzle With 6″ Extension and Chip Shield.  The 1206SS Is Offered In 12″, 18″, 24″, 36″, 48″, 60″ & 72″ Lengths.

1306SS-6-CS
Heavy Duty Safety Air Gun 1306SS-6-CS, Includes 1006SS Back Blow Nozzle With 6″ Extension and Chip Shield.  The 1306SS Is Offered In 12″, 18″, 24″, 36″, 48″, 60″ & 72″ Lengths.

1219ss800
Super Blast Safety Air Gun 1219SS, Includes 1008SS Back Blow Nozzle With 1′ Extension.  The 1219SS Is Offered In 1′, 3′ & 6′ Lengths.

Take it from me EXAIR’s Safety Air Guns fitted with a  Back Blow Nozzles are a must have for any operation that needs to remove debris from pipes, tubes or hose!

If you would like to discuss Safety Air Guns with Back Blow Nozzles or any of our quiet and efficient compressed air devices, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
Send me an email
Find us on the Web 
Follow me on Twitter
Like us on Facebook