Compressed Air Demand Preventative Maintenance

Preventative maintenance for compressed air demand products is a simple as keeping the compressed air clean and condensate free. It is simple because all it takes is a filter and keeping the filter element clean, just like you do for your home furnace and/or air conditioner.

I received a phone call from a customer that needed replacement elements for EXAIR filters.  They were using four different models of Filter Separators and Oil Removal Filters.  The filters had been in service for one year, and the internal elements needed to be changed.  They requested a quote to replenish the replacement elements that they stocked as a preventative measurement.  What an idea!

Majority of EXAIR products use compressed air for cleaning, cooling, conveying, static elimination, coating and more.  To help keep your EXAIR products running efficiently, it is important to supply them with clean, dry, pressurized air.  EXAIR offers a line of Filter Separators and Oil Removal Filters to supply quality air to your equipment.  In this blog, I will explain the two types of filters that we carry and the maintenance requirements.  The filters and preventative measures can play an important part in your compressed air system.

Filter Separators are used to remove bulk liquid and contamination from the compressed air stream.  They utilize a 5-micron filter with a mechanical separation to help remove large amounts of dirt and water.  This type of filter would be considered the minimum requirement for filtration.  Most of the Filter Separators come with an auto-drain to automatically dispense the collection of oil and water.  EXAIR offers a variety of port sizes and flow ranges to meet your pneumatic flow requirement.  For maintenance, the filter elements should be changed once a year or when the pressure drop reaches 10 PSID, whichever comes first.  I created a list in Table 1 showing the correct replacement element kits for each model number.  And for any reason, if the bowl or internal components get damaged, we also have Rebuild Kits as well.  Just remember, the air quality is very important for longevity and functionality for pneumatic products and even for EXAIR products.

The Oil Removal Filters can make your compressed air even cleaner.  They work great at removing very small particles of dirt and oil.  They are made from glass fibers and can remove particles down to 0.01 micron.  They are designed to collect small particles and to coalesce the liquid particles into a large droplet for gravity to remove.  Because of the fine matrix, Oil Removal Filters are not great for bulk separation.  If you have a system with lots of oil and water, I would recommend to use the Filter Separator upstream of the Oil Removal Filter.  As with the Filter Separator, the filter element should be changed once a year or at a pressure drop of 10 PSID.  EXAIR also offers a variety of port sizes and flow ranges.  Table 1 below shows the replacement Element Kits as well as the Rebuild Kits.  If the application requires very clean compressed air, the Oil Removal Filter should be used.

Table 1

By using EXAIR filters, they will clean your compressed air to prevent cross contamination, performance issues, and premature failures.  As an ounce of prevention, you can add the replacement elements in stock and enter them in your preventative maintenance program.  With clean quality air, your pneumatic system and EXAIR products will provide you with effective, long-lasting performance without maintenance downtime.  If you would like to discuss the correct type of filters to use in your application, you can speak with an Application Engineer.  We will be happy to help you.

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

Types of Air Amplifiers: Amplify Volume or Amplify Pressure

EXAIR Air Amplifiers use a small amount of compressed air to create a tremendous amount of air flow.

As Application Engineers, we help many customers with finding solutions with effective, safe, and efficient EXAIR products.  But, in some instances, we get a request for an air amplifier to increase line pressures.  EXAIR does not manufacture this type of Air Amplifier.  In doing some research on the internet, I was able to find two different types of air amplifiers.  In this blog, I will describe the difference between the pressure-type and volume-type.

The EXAIR Super Air Amplifiers are defined as a volume-type of an amplifier.  They use compressed air to generate a large volume of air flow.  The amplification ratio is the comparison between the inlet air flow and the outlet air flow.  With the EXAIR Super Air Amplifiers, we can reach an amplification ratio of 25 to 1.  They use a Coanda profile with a patented shim to create a low pressure to draw in a large volume of the surrounding air.  EXAIR manufactures a variety of different sizes, materials, and types.  But they all do the same thing, amplify the volume of air.  To give an example, model 120024 Super Air Amplifier has a 25:1 amplification ratio.  It uses 29.2 SCFM (826 SLPM) of compressed air at 80 PSIG (5.5 bar).  So, the outlet air flow is amplified from 29.2 SCFM to 730 SCFM (20,659 SLPM) of air.  This large volume of air works great for cooling, exhausting, and transferring.  But, with any type of amplification, you have to lose something.  With the volume type Air Amplifiers, the outlet pressure is reduced dramatically.

The pressure-type air amplifiers are different from the Super Air Amplifiers as this device will amplify the outlet air pressure, not the volume.  It is an air pump that has a direct dual piston that uses two different diameters.  The larger diameter uses the drive inlet pressure while the smaller diameter is used for the boost pressure.  The amplification ratio is determined by the difference in volume from the drive piston to the boost piston.  They also come in a variety of ranges and sizes.  As an example, an amplification ratio of 15:1 will increase an inlet pressure from 100 PSI (7 bar) to an outlet pressure of 1,500 PSI (103 bar).  Since the pressure-type air amplifier is an air pump, the system has to cycle.  To do this, they use pilot valves to either add the inlet compressed air to the drive piston or to relieve the air pressure from the drive piston.  This cycling portion of the operation does reduce the efficiency of the air amplifier.  The pressure-type air amplifiers are used to generate high pressure for a specific application or area and eliminate the purchase of a high-pressure air compressor.  The applications include air clamps and presses, pressure testing, air brakes, and also blow molding.  Like stated above about losing something with amplifications, the volume of air is reduced dramatically.  Generally, a reservoir tank and over-sizing will be needed for a good system.

The Application Engineers at EXAIR enjoy talking to customers about compressed air applications.  If you need more information about Air Amplifiers, you can contact us directly.  We can explain the volume-type that we manufacture or refer you to a company that makes the pressure-type.  Either way, we will be happy to hear from you.

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

Understanding Decibels & Why OSHA Pays Attention to Your Noise Exposure

In the simplest of metric terms, a decibel is one-tenth of a bel.  But, historically, bel was a unit created to honor Alexander Graham Bell who invented the telephone.  In the early days with telephone wires, they noticed that the signal strength would decay over a long distance.  In order to determine power requirements to connect people for communications, they determined that they could use the ratio of power levels.  As a start, it had to be based on a minimum amount of power required for a person to hear on the telephone.  They found that the signal power level to generate an angular frequency of 5000 radians per second would be that minimum value as determined by an average number of people.  They used this mark as a reference point in the ratio of power levels.  Because of the large variations in values, they simplified the equation on a base-10 log scale and dividing the bel unit by 10.  Thus, creating the measurement of decibel.

Today, this same method is used to measure sound.  Like frequency waves that travel through the telephone wires, pressure waves travel through the air as sound.  This sound pressure is what our ears can detect as loudness, and it has a pressure unit of Pascals (Pa).  As an example, a small sound pressure would be like a whisper while a large sound pressure would be like a jet engine.  This is very important to know as high sound pressures, or loudness, can permanently damage our ears.

With sound pressures, we can determine the Sound Pressure Level (SPL) which is measured in decibels (dB).  Similar to the equation for the telephone power signals above, the SPL also uses a ratio of sound pressures in a base-10 logarithmic scale.  For a minimum reference point, an average human can just start to hear a sound pressure at 0.00002 Pa.  So, the equation for measuring sound levels will use this minimum reference point as shown in Equation 1.

Equation 1:

L = 20 * Log10 (p/pref)

where:

L – Sound Pressure Level, dB

p – Sound pressure, Pa

pref – reference sound pressure, 0.00002 Pa

Why is this important to know the decibels?  OSHA created a chart in 29CFR-1910.95(a) that shows the different noise levels with exposure times.  This chart was created to protect the operators from hearing loss in work environments.  If the noise level exceeds the limit, then the operators will have to wear Personal Protection Equipment (PPE), or suffer hearing damage.  EXAIR offers a Sound Level Meter, model 9104, to measure sound levels in decibels.  It comes calibrated to accurately measure the sound to determine if you have a safe work environment.

Sound Level Meter

There is a term that is used when it comes to loud noises, NIHL.  This stands for Noise Induced Hearing Loss.  Once hearing is damaged, it will not come back.  To keep your operators safe and reduce NIHL, EXAIR offers many different types of blow-off products that are designed to decrease noise to a safe level.  So, here’s to Alexander Graham Bell for creating the telephone which can be used to contact EXAIR if you have any questions.

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

 

Photo of Telephone by Alexas_FotosCC0 Create Commons

Back Blow Air Nozzles Clean Out Pipe, Tubes and Holes

Round SS Tubes

A metal fabricator used a cutting machine to cut different sizes and shapes of stainless steel tubing.  The process was automated and the machine would cut two tubes at a time.  After the cutting operation, the machine would deposit the tubes into a nearby bin.  The operator would then stack the tubes in a wooden container as shown above.  Before the tubes could be transported to another department, the operator would have to clean the inside of each tube.  The current method was to attach a rag to the end of a rod and pushed it inside the tube to remove any coolant and chips that remained from the cutting operation.  Of course, the ability to clean thoroughly with a rag is reduced greatly after a short time of use.  The cleaning process was very time consuming, and when the rag was not changed in a timely manner it did not clean effectively.  The inside of the tubes would get marred from the excess chips that remained on the rag.  This would visually affect the surface finish of the stainless steel.  They emailed me the application detail as they were looking for a non-contact way to clean the inside of the tubes.

The first question from the customer was if we could customize our air nozzles to clean the different diameters and shapes that they were cutting.  EXAIR has made special air nozzles to accommodate unique applications, but I wanted to first make sure that EXAIR did not have a manufactured nozzle in stock to fit this application.  I requested the dimensional information, and the customer sent me the sizes and shapes of the tubes that were ran through their cutting machine.  (Reference Table 1 below).

EXAIR manufactures three different sizes of Back Blow Air Nozzles that are designed to clean inside tubing, pipes, hoses, and channels.  They can range from internal diameters from ¼” (6.3mm) to 16” (406mm).  The 360o rear airflow pattern can “wipe” the entire internal surface clean and can remove coolant, chips, and debris.  In reviewing the dimensions from Table 1 above, I was able to recommend just one Back Blow Air Nozzle for all the tubes; even the square and rectangular ones.  It was model 1006SS Back Blow Air Nozzle.  This 316SS robust designed nozzle can fit inside and clean tubes with internal dimensions ranging from 22mm to 102mm, and it was perfect for all of these tubes.

Soft Grip Safety Air Gun w/ Back Blow Air Nozzle

The customer indicated to me that the tubes were all cut to identical lengths at 550 mm (21.7”).  Being that this was a manual operation, I suggested the Back Blow Air Nozzle with our Soft Grip Safety Air Gun.  This ergonomically designed Safety Air Gun is designed for hours of use without fatigue.  In combination with the nozzle, we are able to add extensions and chip shields.  With extensions, EXAIR has a range of lengths from 6” (152mm) to 72” (1,829mm).  With the designated length above, I recommended the model 1206SS-24-CS which has the Soft Grip Safety Air Gun, the model 1006SS Back Blow Air Nozzle, a 24” (610mm) extension, and a chip shield.

The configuration allowed for the operator to reach through the tube to clean with only a one-time pass.  The CS designation is for a chip shield which will protect the operator from any excess debris and coolant.  With the model 1206SS-24-CS, the operator could now pick up a tube, use the Soft-Grip Back Blow Safety Air Gun to remove the debris and coolant from within the round tubes, square tubes and rectangle tubes.  Also, they did not have to worry about changing the rags when it got dirty.  What an amazing purchase for this company, as they increased the speed of the cleaning operation by 70% without affecting the inside finish of the stainless-steel tubes.

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 attach these nozzles on our VariBlast Compact, Soft Grip and Heavy Duty Safety Air Guns for easy-to-use manual operations.  For this customer above, they were glad that they contacted EXAIR about their application.  If you require more details, you can share your application with an Application Engineer at EXAIR.  We will be happy to help.

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

 

Promotional Item: Gen4 Static Eliminators and a free AC Sensor

As the weather gets colder and the air gets dryer, static electricity can become a real nuisance in a production plant.  Machines will start jamming, alignments will be difficult, debris will collect on surfaces, and hazardous sparks can shock personnel.  EXAIR manufactures a large line of Gen4 Static Eliminators to remove this static nuisance.  And beginning January 1st, 2019; EXAIR will be giving away a free AC Sensor, a $57.00 value, with a purchase of any of the Gen4 Static Eliminators.

EXAIR stocks eight different product lines in two different styles, Gen4 Static Eliminators with Air and Gen4 Static Eliminators without Air.  In conjunction with a power supply, these ionizers can create both negative ions and positive ions to remove any type of static charge that is on the surface.  The Gen4 Power Supplies come in either a 2 port or 4 port configuration; so that, you can power multiple Gen4 Static Eliminators at once.  From the power supply to the ionizer, an armored and electromagnetic shielded cable is used in a single wire design. This helps to protect the cable from abrasions, cuts and splits in industrial areas.   The Gen4 Static Eliminators have a shockless design, and are UL Component Recognized and CE compliant.  I will give a brief description of each product that utilizes this rugged industrial design for optimal static neutralization.

Gen4 Static Eliminators with Air:

Gen4 Super Ion Air Knife
  1. Gen4 Super Ion Air Knife: This product has the best compressed air efficiency in removing static by combining the Super Air Knife with an Ionizing Bar.  The Gen4 Super Ion Air Knife has a 40:1 amplification ratio and uses the laminar air flow to carry the positive and negative ions to the surface up to 20 feet (6.1 meters) away.  The laminar air flow also allows for a quick static discharge in applications with fast conveyance speeds.  EXAIR manufactures stock lengths from 3” (76mm) to 108” (2.74 meters).  Some typical applications for the Gen4 Super Ion Air Knife are found in web cleaning, sheeters, pre-paint dust removal, and shrink wrappers.

    Gen4 Standard Ion Air Knife
  2. Gen4 Standard Ion Air Knife: Similar to the Gen4 Super Ion Air Knife, the Gen4 Standard Air Knife has a good efficiency at 30:1 amplification ratio.  It utilizes the Coanda effect to draw in ambient air, and they come in stocked lengths from 3” (76mm) to 48” (1.22 meters).  The Gen4 Standard Ion Air Knife are used in similar applications as well as mold releasing, package cleaning, label applications and plastic bag opening.

    Gen4 Super Ion Air Wipe
  3. Gen4 Super Ion Air Wipe: This product blows ionized air in a 360-degree pattern.  They are engineered to remove static and debris from the outside of hoses, plastic pipes, extrusions, and coated wires.  With the split design, the Gen4 Super Ion Air Wipe can easily mount around the product without having to rethread.  They come in two different sizes with a 2” (51mm) and 4” (102mm) inner diameter. The ionized air has a fast decay in removing static for speedy transfers.

    Gen4 Ion Air Cannon
  4. Gen4 Ion Air Cannon: Just like the name, this product will shower an area with ions to remove static. It can reach distances up to 15 feet (4.6 meters).  They are used in multiple areas including pre-paint car bodies, containers, shrink packaging, lenses, etc.  As an Air Amplifier, a small amount of compressed air will draw in a large amount of ambient air.  The ions are carried to the surface by the Gen4 Ion Air Cannon in a laminar air steam.   Once the ions coat the surface area, the air flow can gently remove any debris held by static forces.

    Gen4 Ion Air Gun
  5. Gen4 Ion Air Gun: For manual static removal to target specific areas, the Gen4 Ion Air Gun will work great.  This product comes standard with 10 feet (3 meters) of shielded cable for maximum reach.  An ergonomic air gun is attached to a Gen4 Ion Air Jet to manually remove static in difficult areas and to pre-treat within “shock” zones.  The Ion Air Guns work great for small batch processes used for quality checks or label applications.

    Gen4 Ion Air Jet
  6. Gen4 Ion Air Jet: Similar to the Ion Air Gun, this product is used for “hands-free” operations. They use a small amount of compressed air to “shoot” the ions onto a target area.  They can be operated with a solenoid valve or foot pedal to blow ions during specific times and situations.  They can easily be attached to a Stay Set Hose and Magnetic Base for best “hands-free” positioning for optimal cleaning.  They work well on small targets for automated systems or inspections areas prior to packaging.

Gen4 Static Eliminators without Air:

Gen4 Ionizing Bar
  1. Gen4 Ionizing Bar: This rugged design is for industrial use to remove static cling from flat surfaces. They range in length from 3” (76mm) to 108” (2.74 meters).  Without the assistance of air, the product has to be within 2 inches (51 mm) from the surface to remove static charges.  The Gen4 Ionizing Bar is compact, shockless and works well in applications where blowing air could be a detriment.  The applications would include screen printing, labeling, and large printing processes.

    Gen4 Ionizing Point
  2. Gen4 Ionizing Point: This single point design is manufactured to remove static on small targets in tight spots.  Utilizing the same rugged design, this product can remove static in spot areas and help to stop jams from slitting operations. They can also be panel mounted to neutralize areas using ducted air.
Model 7929 EXAIR AC Sensor – FREE to end user customers when purchasing ANY EXAIR Gen4 Static Eliminator through March 31st, 2019

Now how about that free promotional item, the AC Sensor, with a purchase of any of the Gen4 Static Eliminators above?  This device, as mentioned above, has a $57.00 value which you can get for free.  This sensor provides a non-contact way to verify if voltage is present.  A red light at the tip will glow, and an audible tone is sounded when voltage is detected.  The model 7929 AC Sensor is an ideal tool to quickly verify that power is going to your ionizer.  This instrument will also work for finding power in receptacles, junction boxes, switches and breaks in power cords.  Batteries will be included, so you can start using it right after receiving the robust Gen4 Static Eliminators.

If you are an end-user and located within the United States or Canada, you can take advantage of this offer until March 31st, 2019.  An Application Engineer at EXAIR will be happy to assist you with your application and a solution with the Static Eliminators.  And if you qualify, a free AC Sensor.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

People of Interest: Rudolf Hilsch

Vortex Tubes

The EXAIR Vortex Tubes use compressed air to generate a cold air stream at one end and a hot air stream at the other end.  The history behind this phenomenon is rooted in the Ranque-Hilsch tube.  In 1931, a French physicist, Georges Ranque, tried to use a cyclone vortex to separate iron filings from the air.  He noticed that when he capped one end with a slight opening, the air would become very warm.  Being disappointed with the separation, he shelved his patented idea for several years.  In 1946, Rudolf Hilsch picked up this idea from Georges Ranque and “tweaked” the design.  This product has now become known as the Vortex Tube.  In this blog, I will cover Rudolf Hilsch as a person of interest.

Rudolf Hilsch was born in December 18th, 1903 in Hamburg, Germany and died on May26th, 1972.  In 1927, Rudolf received his doctorate at the age of 24.  In 1938, he worked with a colleague, Robert Pohl, to create one of the first working semiconductor amplifier.   From 1941 to 1953, Hilsch was a professor of physics at Erlangen, and in 1947, he published his paper of the Ranque-Hilsch tube which he called the “Wirbelrohr”, or whirl pipe.  This publication became well known and was the start of the Vortex Tube.  To continue on with his career, in 1953, he became a full member of the Bavarian Academy of Sciences.  Also, at that same time, he started teaching physics at the Physics Institute of the Georg August University of Göttingen well into the 1960s.

Inside the Vortex Tube

To expand a bit more into his publication, the design for spinning the air at a high rate of speed can produce a separation of temperatures.  It starts with a generator to help facilitate a vortex.  As the vortex travels toward one end, a portion of that air will travel back through the center toward the opposite end.  (Reference animation above).  As these two vortices interact, conservation of momentum forces the inner vortex to give off energy in a form of heat to the outer vortex.  This separation of temperatures will give you a hot air stream and a cold air stream.  This type of device can do this without any moving parts or Freon.  You just have to supply a compressed gas.

EXAIR manufactures Vortex Tubes that utilize this phenomenon with compressed air.  We stock units with cooling capacities up to 10,200 BTU/hr and can reach temperatures from -50oF to +260oF (-46oC to +127oC).  So, thank you Mr. Ranque and Mr. Hilsch for creating a product to generate hot and cold air in a single unit.  If you would like to discuss any applications where cooling or heating is needed, you can talk with one of our Application Engineers.  We will be happy to help.

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

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