The 3 Types of Static Generation

Static electricity is something that we talk about often here at EXAIR, particularly during the colder winter months. When an atom gains or loses an electron from its outer shell, it becomes electrically imbalanced. A material’s propensity to either gain or lose an electron is “ranked” on a list known as the Triboelectric Series. So how does static actually generate, or what causes these atoms to either gain or lose an electron? There are three types of static generation: contact, detachment, and frictional static build up.

Contact static build up is one of the simplest methods of static generation. In this type of static generation, a charge is generated simply from two objects contacting one another and separating. This often results in an instantaneous static charge as the electrons are transferred from one object to another in accordance with the Triboelectric Series.

redplasticbox_peel
As a layer of material is peeled off, electrons are transferred from one sheet to another.

The second type of static generation is known as detachment static buildup. The principle behind the type of static electricity is the same as contact static buildup, but the materials are already in contact with one another and the charge is generated as the surfaces are separated. During the separation, not all of the electrons are able to get back to their original molecule. The amount of static generated in detachment static buildup is generally far greater than contact static buildup due to the large surface area.

BOSE 2

The last type of static generation is frictional static buildup. When two objects have friction between one another, electrons in the outer valences of the molecules can easily pass from one atom to another. If the force pressing the objects together increases, even more molecules come into contact with each other and increase the charge that is generated. Just as detachment static buildup, frictional static buildup generally produces higher charges than contact static buildup.

Gen4 Static
Gen4 Static Eliminators

Regardless of the type of static generation occurring in your process, EXAIR has a Static Eliminator that is suitable for neutralizing that charge and mitigating any issues that you’re having as a result. With a team of Application Engineers standing by to help and our unconditional 30 day guarantee, there’s no reason to not give us a call and try one out!

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

EXAIR Air Nozzles And Jets: Quiet, Efficient, and Safe Solutions For Blow Off

Compressed air, as a utility, dates back to ancient Egypt, where metal alloy production was enhanced by using bellows devices to force air into furnaces in order to generate the extremely high temperatures needed to meld iron ores.  Major industrial use began in the mid-19th century, as pneumatic drills became popular for tunneling and mining operations.  With the development and large scale production of the modern air compressor in the 20th century, many other uses for compressed air were discovered.

Among the most prevalent of these additional applications is cleaning & blow off.  Mechanical or chemical methods such as washing, scrubbing, brushing, wiping, etc. often take time and considerable effort, when a quick blast of high velocity air from a pressurized source can make quick work of debris and/or moisture removal.  Thing is, unfettered discharge of high pressure air without concern for safety or efficiency has consequences:

  • Open end blow offs without a relief path for the air in case the device is dead ended, can have enough energy to break the skin, causing a dangerous and potentially fatal condition known as an air embolism.  The Occupational Safety and Health Administration (OSHA) specifically addresses this danger in 29 CFR 1910.242(b).
  • They’re also incredibly loud, usually higher than 100 decibels, which exceeds OSHA’s noise exposure limits per 29 CFR 1910.95(a).
  • As if that wasn’t enough, they can waste an awful lot of compressed air too.  The U.S. Department of Energy even goes so far as to classify it as an Inappropriate Use of Compressed Air.

Given these drawbacks, you might wonder why ANYONE would do such a thing!  Well, that’s the nature of our business at EXAIR Corporation: manufacturing quiet, safe, and efficient compressed air products for industry.  Among these are the first engineered products developed by EXAIR:  Air Nozzles and Jets.  No matter what your blow off needs are, we’ve got a solution.  Consider:

  • Performance.  With 73 distinct models to choose from, EXAIR can provide blow off solutions from the pin-pointed precision of our Atto Super Air Nozzle (uses 2.5 SCFM, generates 2 oz of force) to our High Force 1-1/4 NPT Super Air Nozzle (uses 460 SCFM, generates 23 lbs of force.)

    From the Atto Super Air Nozzle’s 2.5 oz pinpoint focus of air flow to the Model 1121’s 23 pounds of force blast, EXAIR has 73 distinct models to choose from.
  • Durability.  Some environments where blow off is required are downright aggressive: high heat, exposure to corrosive chemicals, etc.  With these situations in mind, we offer Air Nozzles & Jets in a variety of materials of construction, as shown to the right:
    • Zinc Aluminum alloy
    • Types 303 and 316 Stainless Steel
    • PEEK (polyether ether ketone) thermoplastic
    • Aluminum
    • Brass
  • Range of operation.  Any blow off device’s performance can be varied by regulating the compressed air supply pressure.  EXAIR offers several products with even greater ability for change:
    • The Model 1009 (Aluminum) and 1009SS (303SS) Adjustable Air Nozzles have a micrometer-like dial that allows you to very precisely set the flow & force to exact requirements.
    • Adjustable Air Jet Models 6019 (brass) and 6019SS (303SS) feature similar operation with a micrometer-like gap adjuster/indicator.
    • Our 1″ and 2″ Flat Super Air Nozzles (available in Zinc Aluminum or 316SS) have a replaceable shim.  The standard models have a 0.015″ thick shim installed, and the High Power models have 0.025″ thick shims.  We also offer individual shims, and sets, ranging from 0.005″ to 0.030″ thicknesses.
    • High Velocity Air Jets come in brass or 303SS, and also have replaceable shims.  The one that comes installed is 0.015″ thick.  The Shim Set gives you a 0.006″ and 0.009″ shim.

      Adjustable Air Nozzles & Jets (left) feature micrometer-type adjustment; Flat Super Air Nozzles and the High Velocity Air Jet (right) have replaceable shims to vary performance.
  • Function. Most of our Air Nozzles generate a high velocity air stream coming straight from its end.  We’ve also engineered some nozzles for specific applications:
    • Model 1144 2″ Super Air Scraper is our popular 2″ Flat Super Air Nozzle with a corrosion resistant scraper blade, making quick work of removing stubborn materials like tape, gaskets, labels, grease, paint, or sealant.  It’s particularly handy when installed on a Soft Grip Safety Air Gun with an appropriate length of pipe extension.
    • Back Blow Air Nozzles are made to clean out inside diameters or blind holes.  Three sizes are available for ID’s of 1/4″ to 16″.

If you’d like to find out more about how EXAIR Intelligent Compressed Air Products can help you get the most out of your compressed air system, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Eliminating Static in Industrial Processes

Ever wonder what causes that annoying shock you get when you go to grab a plastic or metal piece. That is a phenomenon caused by static electricity. This static is an electrical surface charge that is generated and when two surfaces come in contact with each other and generate an electrical charge from friction, separation, or simple contact. If the material in question is not grounded properly the electrical charge will continue to accumulate until it comes in contact with a proper ground or the path of least resistance to discharge the built up static and return to a neutral state.

Static

Static is generated on the atomic level from the exchange of valance electrons on each surface. The energy produced from the friction, separation or contact cause those valance electrons to enter an excited state; when in this excited state they begin to jump back and forth from atom to atom. When this happens, the atoms begin to accumulate either a positive charge if the atom lost electrons or a negative charge if the atom gained electrons. As the charge accumulates on the surface were the friction occurs if a ground source (i.e. piece of metal or a person) comes in close proximity to the charged surface an arc is generated between the two surfaces returning the originally charged surface to a neutral state.

Static can be harmful to both employees and product in an industrial environment. If a static arc is generated in the presence of either flammable, combustible, or explosive liquids or gasses the arc can cause an ignition of the material. Static can also cause the charged object to stick or cling to various surfaces causing clogs in pipes and issues when trying to separate the material one at a time. This phenomenon is called static cling.

Even though static is very easy to generate it can just as easily be dissipated; EXAIR’s line of static eliminating devices use a high voltage emitter point to generate a small zone of ions which consists of both positive and negative charges to dissipate the static build up on the surface. Also, when the various emitter points and ion bars are coupled with our compressed air products, the air carries the ions much farther and can dissipate static up to 20’ away. The best part is that about the line of our line of static eliminators is that they are shockless; this means that if somebody bumps into it, they won’t get shocked.

Gen 4 Super Ion Air Knife Eliminating Static with Ions

For more information on EXAIR’s Static Eliminators and any of EXAIR‘s 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.

Cody Biehle
Application Engineer
EXAIR Corporation
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Laminar Flow and Digital Flowmeters: An Explanation On How To Achieve Laminar Flow

When I see turbulent flow vs. laminar flow I vaguely remember my fluid dynamics class at the University of Cincinnati.  A lot of times when one thinks about the flow of a liquid or compressed gas within a pipe they want to believe that it is always going to be laminar flow. This, however, is not true and there is quite a bit of science that goes into this.  Rather than me start with Reynolds number and go through flow within pipes I have found this amazing video from a Mechanical Engineering Professor in California. Luckily for us, they bookmarked some of the major sections. Watch from around the 12:00 mark until around the 20:00 mark. This is the good stuff.

The difference between entrance flow, turbulent flow and laminar flow is shown ideally at around the 20:00 mark.  This length of piping that is required in order to achieve laminar flow is one of the main reasons our Digital Flowmeters are required to be installed within a rigid straight section of pipe that has no fittings or bends for 30 diameters in length of the pipe upstream with 5 diameters of pipe in length downstream.

This is so the meter is able to measure the flow of compressed air at the most accurate location due to the fully developed laminar flow. As long as the pipe is straight and does not change diameter, temperature, or have fittings within it then the mass, velocity, Q value all stay the same.  The only variable that will change is the pressure over the length of the pipe when it is given a considerable length.

Another great visualization of laminar vs. turbulent flow, check out this great video.

 

If you would like to discuss the laminar and turbulent flow please contact an Application Engineer.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

1 -Fluid Mechanics: Viscous Flow in Pipes, Laminar Pipe Flow Characteristics (16 of 34) – CPPMechEngTutorials – https://www.youtube.com/watch?v=rQcZIcEa960

2 – Why Laminar Flow is AWESOME – Smarter Every Day 208 – SmarterEveryDay – https://www.youtube.com/watch?v=y7Hyc3MRKno

 

 

Basics of the Compressor Room

EXAIR Corporation has staked our reputation on a keen ability to help you get the most out of your compressed air system since 1983.  Now, the bulk of our expertise lies in the implementation and proper use of engineered products on the demand side, but we fully recognize that there are critical elements for optimization on the supply side too.  And that, quite literally, starts in the compressor room.  This is not an exhaustive, specifically detailed list, but here are some you might consider to get the most from the (again, quite literally) beginning:

  • Location.  If you’re building a new facility, or doing a major rehab of your existing one, having the compressor room as close as practical to the point(s) of use is best, IF all other things are equal.  You’ll use less pipe if you don’t have to run it so far.  You’ll also be able to use smaller diameter lines because you won’t have to worry about line loss (pressure drop due to friction as the air flows through the total length) as much.
  • Location part 2.  If all other things are NOT equal, having the compressor room close to the point of use may not be best for you.
    • Your air compressor pulls in air from the immediate environment.  It’s better to go with longer and bigger pipe in your distribution system than it is to put your compressor in a location where it’ll pull in dust & particulate from grinding operations, humidity from a boiler plant, fumes from chemical production, etc.
    • There are some pretty darn quiet air compressors out there, but there are some pretty loud ones too.  Especially in small to mid size facilities, putting the compressor in an area that upsizes the required piping is still likely a better idea, due to the downsizing of the noise levels that personnel will be exposed to.
  • Environment.  No matter where your compressor is located, the machine itself should be protected from heat and other harsh environmental elements.  That means if it’s inside the plant, the compressor room should be adequately ventilated.  In some situations, the compressor may be best installed outside the plant, in its own building or protective structure.  This should be designed to protect against solar load…in addition to the high temperature associated with a hot summer day, the sun’s rays beating down on your air compressor will radiate a tremendous amount of heat into it.
  • Filtration.  Whatever is in the air in your compressor room is going to get into your compressed air.  This is doubly problematic: particulate debris can damage the air compressor’s moving parts, and it can likewise damage your pneumatic cylinders, actuators, tools, motors, etc. as well.  Make sure the intake of your compressor is adequately filtered.
  • Maintenance.  Air compressors, like any machinery with moving parts, require periodic preventive maintenance, and corrective maintenance when something inevitably breaks down.  There should be adequate space factored in to your compressor room’s layout for this.  The only thing worse than having to fix something is not having the room to fix it without taking other stuff apart.

Patrick Duff, a production equipment mechanic with the 76th Maintenance Group, takes meter readings of the oil pressure and temperature, cooling water temperature and the output temperature on one of two 1,750 horsepower compressors. Each compressor is capable of producing 4,500 cubic feet of air at 300 psi. The shop also has a 3,000 horsepower compressor that produces 9,000 cubic feet of air at 300 psi. By matching output to the load required, the shop is able to shut down compressors as needed, resulting in energy savings to the base. (Air Force photo by Ron Mullan)

These are a few things to consider on the supply end.  If you’d like to talk about how to get the most out of your compressed air system, EXAIR is keen on that.  Give us a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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The Perseverance to Help Out

A couple of years ago I got to spend some time with my dad rock climbing in the North Cascades in Washington. My eyes were set on a very easy 5.9 big wall multi-pitch route called Prime Rib of Goat on the Goat Wall in Mazama. The route that we climbed was 1300ft of vertical cliff and one of the most popular beginner routes for getting into large climbs. Both my dad and I are knowledgeable when comes to climbing and were looking for a nice relaxing day on the wall. This is how that relaxing day turned into a crazy rescue…

The trip started out as any normal climbing trip would, an early 6 am flight as we had to get all of our climbing gear through airport security. Once the plane landed, we picked up our rental car and the gorgeous 3.5 hr drive up I-5 along the bay and straight on through the North Cascade National Park. Mazama is a small town with a population of only 158 people located on the East side the Cascades. Once we reached our destination and set up camp, we decided to do a little warm up on the wall to try and beat the stiffness and fatigue from a full day of travel.

Pitch 7 of the Prime Rib of Goat on the Goat Wall

The next morning, we woke up a little on the late side (around 7:30 am) got a light breakfast and set out for our goal the Goat Wall. The wall was a short 3 miles outside of town with a not so easy 1-mile hike in 95°F temperatures up a Scree field (basically hill of loose rock at the base of a mountain). Once we reached the base, we loaded up our gear onto our harnesses and started climbing to the first set of anchors (this is what is known as a pitch in climbing terms). Pitches 1 – 6 were fairly straight forward and easy going, water was rationed to ensure that we wouldn’t get dehydrated but at the same time wouldn’t run out of water.

By around 4:00 pm we had reached the halfway point at the top of pitch 6; this is where we ran into two people who were also climbing the same route as us but moving at a much slower pace. Luckily the were two trees that were growing on the cliff so we decided to take a small lunch break in the shade. Around a half hour later I shouted up the cliff to see if the two people had moved on yet; when I heard nothing we started climbing pitch 7. To my surprise the group ahead of us were still sitting at the top of pitch 7.

Pitch 7 of the Prime Rib of Goat on the Goat Wall

Turns out that the group had a 40 pound pack with them which was unusual for the single day climb on an easy route that could be easily terminated if needed. After another 10 mins of waiting we decided help them haul this pack of theirs up the wall. It was slow moving up to Pitch 8 and they had run out of water and our water was running low. By the time we had finally reached pitch 9 with all the people things had started to get worse for the group that we were assisting; fatigue and dehydration had brought them to the point of a mental break down.

At this point my dad and I decided to share the last bit of water we had with them and to turn around and bail on the last 3 pitches. It was a slow process moving back down the way we had come and try to keep the group calm; the sun and heat was really starting to take a toll on our bodies. Our lips were cracked and blistered and our mouths had quit producing saliva but we kept trudging on. A relief from the heat came around the time when the sun had set around the top of pitch 4 and from that time onward, we were descending down the cliff face into what seemed like a black abyss.

Finally, we were able to set foot on the ground and low and behold the friends of the group we helped had hiked to the base looking for their friends and they brought water we could all drink. We didn’t get back to the campsite until 1:00 am. The next day my dad and I decided to pack up and head to the coast because we were done climbing.

Here at EXAIR we like to bring that same kind of enthusiasm and perseverance to help you solve your compressed air issues. We will walk you step by step in getting you either the right part or solving any of your technical issues and won’t leave you high and dry.

If you want to talk 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.

Cody Biehle
Application Engineer
EXAIR Corporation
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Super Ion Air Wipes – Eliminate Static on Wire, Cable, Extrusions

Gen4 Super Ion Air Wipe

As the colder dryer months are upon us, static electricity will be more frequent and will become a real nuisance.  Machines will start jamming, alignments will be difficult, dirt will collect to surfaces, and hazardous sparks can shock personnel.  EXAIR manufactures a line of Gen4 Static Eliminators to remove this nuisance.

EXAIR manufactures eight different product lines in two different styles within our Gen4 Static Eliminators.  In this blog, I will be covering the 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 pipe, extrusions, and coated wires.  With a split design, the Gen4 Super Ion Air Wipe can easily mount around the product without having to re-thread.  EXAIR stocks two different sizes with a 2” (51mm) and 4” (102mm) inside diameter. The Super Ion Air Wipes give a fast static-decay, a shockless and non-radioactive design, variable flow and force, low air consumption and no moving parts.

8462 Super Ion Air Wipe Kit

The Gen4 Super Ion Air Wipe can be purchased as a kit which will include the power supply (required for ionization), a filter separator (to clean contamination from the compressed air), and a pressure regulator (to control the blowing force).  The filter and regulator are properly sized to avoid any air flow restrictions or loss of performance which can occur when using components which are not suited for the application.

Static

Generally speaking, static is generated from non-conductive surfaces being “rubbed”.  This could be from going over rollers on a conveyor, stacking product onto each other, sheet feeding, and even peeling away a backing material.  When non-conductive surfaces, or insulators, are moved or separated, electrons are “stripped” and redistribute on to different areas of the surface.  Static charges are typically measured in kilovolts (kV), or 1,000 volts, and they can be either positive or negative.  The higher the charge, the stronger the static force.  In reference, at 10 kilovolts, a spark can jump one inch (25 mm) from the surface.   EXAIR offers a Digital Static Meter, model 7905, to measure the amount of static voltage on a surface.  It is a great tool for finding problem areas in your process as well as determining the effectiveness of the treatment.

All EXAIR Gen4 Static Eliminators use one of two Power Supplies – your choice of the 2-port Model 7960, or the 4-port Model 7961.

These ionizers are powered by a 5,000V AC power supply.  The alternating current, AC, will create both negative ions and positive ions.  So, no matter the polarity of charge on the surface, the Gen4 Static Eliminators will be able to remove it.  The power supplies come in either a 2 port or 4 port design so you can power multiple Gen4 Static Eliminators with one power supply.  The input power is selectable from either 115VAC or 230VAC in both 50/60 Hz.   Two armored and electromagnetic shielded cables connect the Super Ion Air Wipe to the power supply. This will help to protect the cable from abrasions, cuts and splits which can be common in rugged industrial areas.

Static can be a real nuisance with shocking operators, “sticking” debris, and jamming processes.  If you run into these issues in your application, no matter the shape, EXAIR has a Gen4 Static Eliminator for you.  Even if you have cylindrical objects like tubes, pipes, hoses and extrusions; EXAIR can provide the Gen4 Super Ion Air Wipes in stock.  For more information, you can contact one of our Application Engineers at EXAIR.

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