EXAIR Standard Air Knife: Engineered For Performance

In 1983, EXAIR Corporation was founded with the goal of engineering & manufacturing quiet, safe, and efficient compressed air products for industry.  By 1988, the EXAIR-Knife (now known as the Standard Air Knife) was quickly becoming the preferred choice for replacing loud and inefficient drilled pipes, long nozzle manifolds…anywhere an even, high velocity curtain of air was required.

The EXAIR Standard Air Knife’s design takes advantage of a fascinating principle of fluidics to achieve quiet and efficient operation: the Coanda Effect, which is the tendency of a fluid jet to stay attached to a convex surface.  If you want to see it for yourself, hold the back of a spoon, handle up, under the kitchen faucet.  Those who haven’t seen it before may assume that gravity will take over and the water will fall from the bottom of the spoon’s ‘bowl’ – but it doesn’t:

Likewise, the air flow (which is just another example of a fluid jet) exiting the Standard Air Knife’s shim gap follows a convex surface (which we call the “Coanda profile”) causing it to entrain large amounts of air from the surrounding environment:

Compressed air flows through the inlet (1) to the Standard Air Knife, into the internal plenum. It then discharges through a thin gap (2), adhering to the Coanda profile (3) which directs it down the face of the Air Knife. The precision engineered & finished surfaces optimize entrainment of air (4) from the surrounding environment.

This entrainment does two things for us:

  • First, because we’ve engineered the design for maximum entrainment, it’s very efficient – creating a high flow rate, while minimizing air consumption.  In the case of the Standard Air Knife, the entrainment ratio is 30:1.
  • Secondly, this entrainment forms an attenuating boundary layer for the air flow, resulting in a high velocity, high volume airflow that is also incredibly quiet.

The EXAIR Standard Air Knife comes in lengths from 3″ to 48″, and in aluminum or 303SS construction.  All sizes, in both materials, are on the shelf and available for immediate shipment.  For most applications, we recommend the Kit, which includes a Shim Set (to make gross changes to flow & force,) an Automatic Drain Filter Separator (keeps the air clean & moisture free,) and a Pressure Regulator (to dial in the performance.)  Deluxe Kits add our Universal Air Knife Mounting System and EFC Electronic Flow Control.

(From left to right) Aluminum Standard Air Knife Kit, SS Standard Air Knife Kit, Deluxe Aluminum Standard Air Knife Kit, Deluxe SS Standard Air Knife Kit.

If you need a hard hitting curtain of air for blow off, drying, cleaning, cooling, environmental separation, etc., the EXAIR Standard Air Knife is an easy and economical solution.  If you’d like to discuss your application and/or product selection, give me a call.

Russ Bowman

Application Engineer
EXAIR Corporation
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Air Operated Conveyors for a Multitude of Jobs

With 119 distinct Models, EXAIR Line Vacs are used to convey everything from down feather to steel shot.  They’re versatile, reliable, durable, and incredibly easy to install and operate. Most applications can be completed using one of our many stock Line Vacs. Additional applications include part transfer, waste or trim removal, hopper loading, filling operations, chip removal and fiber tensioning.

line vac family
Lightweight and durable aluminum is the most popular choice, but we make them in stainless steel (Types 303 and 316) for heat and corrosion resistance. For extreme heat, the High Temperature option affords protection to 900F (482C) in either 303SS or 316SS.

They are available from 3/8″ to 5″ diameters, for use with hose, tube or pipe. Line VAcs have smooth ends for hose or tube. The threaded models use NPT threads from 3/8 NPT to 3 NPT to turn ordinary pipe into an air conveyor! They can also be bought with sanitary flange ends for easy disassembly when necessary for cleaning or maintenance.

Materials include aluminum, Type 303 and Type 316 stainless steel or a hardened steel alloy for moving abrasive materials like garnet, glass, or blasting media.

With that being said, there are always applications that need a special product. And because of that we do make “special” or custom products when the need arises.

Special PVDF Line Vac

For example this Live Vac has the sanitary flange design, but the customer needed it made from a special material so their product passing through it wouldn’t be contaminated by metal. So we did just that, we designed built and shipped this line vac and it worked amazingly well!

Accessories include the transport hose, mounting brackets, filter and regulators.  A filtering drum cover is very useful to keep material and/or dust inside, when transporting materials into a drum.

No matter what kind of bulk material you need to move, or what type of special conditions you have. EXAIR has a Line Vac product for it.  If you’d like to find out more, give me a call.

Jordan Shouse
Application Engineer
EXAIR Corporation
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Solving Performance Issues of Air Operated Industrial Vacuums

This blog will focus on the EXAIR Chip Vac, but the troubleshooting process and steps for achieving optimal performance are consistent among EXAIR’s entire line of air operated industrial vacuums.

There’s really not that much that CAN go wrong with an EXAIR Chip Vac System. They have no moving parts to wear or electrical components to burn out. As long as they’re supplied with clean air, they’ll run darn near indefinitely, maintenance free.

Murphy’s Law, of course, is still in full force, so if something CAN go wrong, it WILL go wrong.  The Chip Vac is, alas, no exception.  Good news is, because of the Chip Vac‘s simplicity, troubleshooting is simple as well.  The most common problems we see with ANY of our engineered compressed air products (not just the Industrial Vacuums) are related to compressed air supply:

  • New users might not consider the air demand required by a new product, and may provide an inadequate supply line.  The Chip Vac, for example, will consume 40 SCFM @80psig for rated operation, and will need a 1/2″ (inside diameter) hose to supply that, assuming a length of no more than 20ft.  Hooking one up to a common 3/8″ hose on a 50ft reel, for example, will “starve” the Chip Vac, resulting in degraded performance.
  • Also, the preferred method of connection is a hose with threaded fittings on the ends.  A local hydraulics/pneumatics shop can likely make these, while you wait.  Push-to-connect quick connect fittings are restrictive by nature, and should be avoided.  Quarter turn claw-type fittings are great…the main drawback (which can be solved with an upstream shutoff valve) is the line has to be depressurized to make or break the connection.
  • If you absolutely want to use a push-to-connect type, you can oversize it (use one made for larger hose with, say, 3/4 NPT fittings) and use bushing/adapters to get to your actual hose size.

    If you must use quick connects, the 1/4 turn claw type (left) is the least restrictive. Push-to-connects (center) are likely to starve your product, unless you oversize them (right) like we do in our Efficiency Lab.
  • Speaking of supply issues, make sure nobody’s bumped into a valve handle & partially closed it (I have,) ignored the maintenance schedule & didn’t change a clogged filter element (I have,) or ran something into a copper line hard enough to crimp it, but not rupture it (I haven’t…that was Tim, who, aside from this incident, was really pretty good with a forklift.)

The issues above apply to not only any compressed air system, but most fluid power/fluid handling systems.  Since this blog is about Chip Vac troubleshooting, let’s move on to some specifics.  If you’re sure you’re getting proper air supply to the Chip Vac (by the way, a pressure gauge right at the inlet – like the one that comes with our Premium Chip Vac System’s air hose – will eliminate any doubt,) then let’s look at some potential issues downstream:

  • Dirt & debris can collect inside the Chip Vac itself, obstructing the outlet holes, and lowering your vacuum flow.  You can disassemble and clean it pretty easily, though.
  • The Filter Bag can get clogged, especially if you’re vacuuming up a lot of dust or powdery materials.  If this happens, turn the Chip Vac off and shake the Filter Bag to dislodge the material, allowing it to fall back into the drum where it belongs.
  • Speaking of which, if you find that, all of a sudden, the Filter Bag is clogging, remove the drum lid and check for the Silencing Hose.  This serves two functions…the first is in the name (just a little discharge hose mitigates the sound level of the Chip Vac‘s exhaust flow.)  Secondly, it directs the vacuumed material positively into the drum, limiting the amount that is “dust-storms” in the upper area of the drum, where it’s more prone to make it into the Filter Bag.
Pro tip: check for the Silencing Hose when you remove the lid to empty the drum. DON’T throw the Silencing Hose in the trash.

I’m not going to unequivocally state that this is an all-inclusive list (see “Murphy’s Law,” above,) but these are the Usual Suspects if you’re just not getting the most out of your Chip Vac.  If you ever have any questions, though, give us a call.  We’re here to help.

Russ Bowman
Application Engineer
EXAIR Corporation
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Vortex Tube Cold Fractions Explained

Simply put, a Vortex Tube’s Cold Fraction is the percentage of its supply air that gets directed to the cold end. The rest of the supply air goes out the hot end. Here’s how it works:

The Control Valve is operated by a flat head screwdriver.

No matter what the Cold Fraction is set to, the air coming out the cold end will be lower in temperature, and the air exiting the hot end will be higher in temperature, than the compressed air supply.  The Cold Fraction is set by the position of the Control Valve.    Opening the Control Valve (turning counterclockwise, see blue arrow on photo to right) lowers the Cold Fraction, resulting in lower flow – and a large temperature drop – in the cold air discharge.  Closing the Control Valve (turning clockwise, see red arrow) increases the cold air flow, but results in a smaller temperature drop.  This adjustability is key to the Vortex Tube’s versatility.  Some applications call for higher flows; others call for very low temperatures…more on that in a minute, though.

The Cold Fraction can be set as low as 20% – meaning a small amount (20% to be exact) of the supply air is directed to the cold end, with a large temperature drop.  Conversely, you can set it as high as 80% – meaning most of the supply air goes to the cold end, but the temperature drop isn’t as high.  Our 3400 Series Vortex Tubes are for 20-50% Cold Fractions, and the 3200 Series are for 50-80% Cold Fractions.  Both extremes, and all points in between, are used, depending on the nature of the applications.  Here are some examples:

EXAIR 3400 Series Vortex Tubes, for air as low as -50°F.

A candy maker needed to cool chocolate that had been poured into small molds to make bite-sized, fun-shaped, confections.  Keeping the air flow low was critical…they wanted a nice, smooth surface, not rippled by a blast of air.  A pair of Model 3408 Small Vortex Tubes set to a 40% Cold Fraction produce a 3.2 SCFM cold flow (feels a lot like when you blow on a spoonful of hot soup to cool it down) that’s 110°F colder than the compressed air supply…or about -30°F.  It doesn’t disturb the surface, but cools & sets it in a hurry.  They could turn the Cold Fraction down all the way to 20%, for a cold flow of only 1.6 SCFM (just a whisper, really,) but with a 123°F temperature drop.

Welding and brazing are examples of applications where higher flows are advantageous.  The lower temperature drop doesn’t make all that much difference…turns out, when you’re blowing air onto metal that’s been recently melted, it doesn’t seem to matter much if the air is 20°F or -20°F, as long as there’s a LOT of it.  Our Medium Vortex Tubes are especially popular for this.  An ultrasonic weld that seals the end of a toothpaste tube, for example, is done with a Model 3215 set to an 80% Cold Fraction (12 SCFM of cold flow with a 54°F drop,) while brazing copper pipe fittings needs the higher flow of a Model 3230: the same 80% cold fraction makes 24 SCFM cold flow, with the same 54°F temperature drop.

Regardless of which model you choose, the temperature drop of the cold air flow is determined by only two factors: Cold Fraction setting, and compressed air supply pressure.  If you were wondering where I got all the figures above, they’re all from the Specification & Performance charts published in our catalog:

3200 Series are for max cooling (50-80% Cold Fractions;) 3400’s are for max cold temperature (20-50% Cold Fractions.)
Chocolate cooling in brown; welding/brazing in blue.

EXAIR Vortex Tubes & Spot Cooling Products are a quick & easy way to supply a reliable, controllable flow of cold air, on demand.  If you’d like to find out more, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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EXAIR Line Vacs: Dozens Of Models; Endless Applications

With 119 distinct Models, EXAIR Line Vacs are used to convey everything from down feather to steel shot.  They’re versatile, reliable, durable, and incredibly easy to install and operate.  Consider this list of uses, starting with our smallest Line Vac, and going to our largest:

  • Model 6058 3/8″ Stainless Steel Line Vacs pull mica from a bulk container and spray it into a mold for making decorative stones, to apply a glittery surface.  They used to do it by hand, but the Line Vacs spread it more consistently.
  • A Model 6079 1/2″ Aluminum Line Vac pulls small metal scraps from a metal trimming operation, as they’re cut, keeping the work area clean.
  • Model 130075 3/4″ Light Duty Line Vacs perform a similar function in a plastic cutting machine, conveying away cut chips and eliminating the need for periodically stopping the machine to clean up.
  • A medical device manufacturer saw a 50% increase in productivity when they went from removing flash by hand from molded silicon parts to using a Model 6061 1″ Stainless Steel Line Vac to suction it away automatically.
  • A mining equipment manufacturer reclaims sand from a secondary operation on their green sand molds with a Model 6062 1-1/4″ Stainless Steel Line Vac.  This keeps their mold area clean, and has eliminated waste in production.
  • Model 140125 1-1/4 MNPT Aluminum Threaded Line Vacs eliminated a  “bucket and ladder” operation where cotton seeds needed to be loaded into 7-foot high hoppers.
  • Model 151150 1-1/2 MNPT Heavy Duty Threaded Line Vacs, fitted into black iron pipe systems, reclaim hot metal chips from a deep channel milling machine, automating the transfer to the recycling hopper.  This eliminated the risk of lifting AND burn injuries from the manual handling of the hot chips.
  • Model 6084 2″ Aluminum Line Vacs vacuum trim scrap from custom label making machines to a central scrap bin, keeping the floor clean, and keeping operators from having to empty individual bins at each machine.
  • A Model 6065 2-1/2″ Stainless Steel Line Vac conveys rejected peanuts (identified and segregated by a vision sorting machine) from the catch pan to a large collection hopper.  This is hauled away at the end of each shift, instead of an operator paying constant attention to the catch pan.
  • Model 161300-316 3″ Sanitary Flange Line Vacs replaced mechanical conveyors in a grain mill, incorporating a totally enclosed Clean In Place (CIP) system.  This greatly reduced contamination controls when the product was openly conveyed, and actually increased their conveyance rates of their bulk grains.
  • A Model 6087 4″ Aluminum Line Vac conveys an additive (in pellet form) into an asphalt mixer, replacing an auger conveyor that left product in the hopper and would clog regularly, resulting in messy spills.
  • A company that recycles spent ammo from gun ranges uses a Model 6088 5″ Aluminum Line Vac to convey the granulated rubber backstop material into their truck.  After the ammo is separated, they use the Line Vac to replenish the granulated rubber into the backstop.
  • A Model 130600 6″ Light Duty Line Vac conveys linen squares (mostly 12″ and 24″ square) through the main header of a sorting operation in a commercial laundry facility.  The system also incorporates several Model 120024 4″ Super Air Amplifiers in individual “pickup” branches.
The EXAIR Line Vac is a fast, low cost way to convey most any bulk material.

No matter what kind of bulk material you need to move, EXAIR has a Line Vac product for it.  If you’d like to find out more, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Don’t Forget About Operating Cost: How To Calculate Return On Investment

If you have a stock portfolio, or even a retirement account, you’ve likely heard the term “return on investment.” It basically tells you how hard your money is working for you, and, the higher, the better.

The term is also used to determine the financial benefits associated with the use of more efficient products than you’re using right now:

  • The cost of operating industrial pumps, air compressors, and a variety of industrial rotating equipment, can be greatly reduced by using variable frequency drive systems that sense the demand and change the motor’s speed (and hence power consumption) accordingly.  These systems are not cheap, but the reduction in operating costs is often quite noticeable.
  • At home, installing energy efficient windows (spoiler alert: your builder probably used the cheapest ones he could find…mine sure did) or upgrading appliances & HVAC can cost a pretty penny, but you’ll also see your electric bill go down.

EXAIR Corporation has a worldwide reputation for providing highly efficient compressed air products for industry.  Our Engineering Department has a company-wide reputation for being data fanatics…which is key to allowing us to provide our customers with ample information to make the best choices to optimize your use of your compressed air.

It’s not hard at all to calculate your potential savings from the use of an engineered compressed air product, assuming you know how much air your current device is using.  If not, we can tell you if you can send it in for Efficiency Lab testing (free and fast; call me to find out more.)  Here’s an example for a VERY typical situation: replacing an open copper tube blow off with an EXAIR Super Air Nozzle:

  • A 1/4″ copper tube uses 33 SCFM @80psig
  • A Model 1100 Super Air Nozzle uses 14 SCFM @80psig

33 SCFM X 60 min/hour X 8 hours/day X 5 days/week X 52 weeks/year = 4,118,400 SCF

14 SCFM X 60 min/hour X 8 hours/day X 5 days/week X 52 weeks/year = 1,747,200 SCF

4,118,400 – 1,747,200 = 2,371,200 Standard Cubic Feet of compressed air savings

If you know your facility’s cost of compressed air generation, you can calculate the monetary savings.  If not, we can get a good estimate via a thumbrule used by the U.S. Department of Energy that says it typically costs $0.25 to generate 1,000 SCF of compressed air:

2,371,200 SCF X $0.25 ÷ 1,000 SCF = $592.80 annual monetary savings

In 2019, the cost of a Model 1100 Zinc Aluminum Super Air Nozzle is $41.00.  Daily savings (not counting weekends) is:

$592.80 ÷ 260 days (5 days/week X 52 weeks/year) = $2.28 daily savings

Meaning the payoff time for the $41.00 investment in the Model 1100 is:

$41.00 ÷ $2.28 = 17.9 days

Or…just over three weeks.  Now that I’ve shown you the math, I’d like to introduce you to the EXAIR Cost Savings Calculator.  Just enter the data, and it’ll check your math (because I know you’re going to do the math anyway, just like I would.)  It even does the ROI for you too.

Engineered solutions (like EXAIR Intelligent Compressed Air Products) are the efficient, quiet, and safe choice. Does the one on the right look familiar?  It’s literally the example I used for the above calculations.

If you’d like to find out more about how – and how fast – EXAIR Intelligent Compressed Air Products can pay off for you, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Business Benefits From Compressed Air Efficiency

Use of compressed air, or “the fourth utility” as it’s called, is widespread in many industries.  How you use it in your business is important, for a couple of key considerations:

Monetary cost

Compressed air isn’t free.  Heck, it isn’t even cheap.  According to a Tip Sheet on the U.S. Department of Energy’s website, some companies estimate the cost of generation at $0.18 – $0.30 per 1,000 cubic feet of air.  A typical industrial air compressor will make 4-5 Standard Cubic Feet per Minute per horsepower.  Let’s be generous and assume that our 100HP compressor puts out 500 SCFM and is fully loaded 85% of the time over two shifts per day, five days a week:

500 SCFM X $0.18/1,000 SCF X 60 min/hr X 16 hr/day X 5 days/week X 52 weeks/year =

$22,464.00 estimated annual compressed air cost

If you want to go jot down some numbers from your compressor’s nameplate and your last electric bill, you can accurately calculate your actual cost.  Here’s the formula:

Taking our same 100HP compressor (105 bhp required,) fully loaded 85% of the time, and assuming the motor’s good (95% efficient):

(105 bhp X 0.746 X 4,160 hours X $0.08/kWh X 0.85 X 1.0)÷ 0.95 =

$23,324.20 actual annual compressed air cost

So, our estimate was within 4% of our actual…but the point is, $22,000 to $23,000 is a significant amount of money, which deserves to be spent as wisely as possible, and that means using your compressed air efficiently.  Engineered solutions like EXAIR Intelligent Compressed Air Products can be a major part of this – look through our Case Studies; implementing our products have saved companies as much as 60% on their compressed air costs.

Health & Safety

Injuries and illnesses can be big expenses for business as well. Inefficient use of compressed air can be downright unsafe.  Open ended blow offs present serious hazards, if dead-ended…the pressurized (energized) flow can break the skin and cause a deadly air embolism.  Even some air nozzles that can’t be dead ended (see examples of cross-drilled nozzles on right) cause a different safety hazard, hearing loss due to noise exposure.  This is another case where EXAIR can help.  Not only are our Intelligent Compressed Air Products fully OSHA compliant in regard to dead end pressure, their efficient design also makes them much quieter than other devices.

Efficient use of compressed air can make a big difference in the workplace – not only to your financial bottom line, but to everyone’s safety, health, and livelihood.  If you’d like to find out more about how EXAIR can help, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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