How a Super Air Knife Helps with Metal Etching

Etching Machine

A company had a process where they were etching metal components with an acid bath.  The system consisted of four baths where the metal parts would be dipped.  The four baths consisted of a wash, rinse, acid bath, and rinse again.  The automated system was contained inside an enclosed booth; and, once the parts were placed inside a 24” (610mm) X 18” (457mm) basket, a sliding door was closed to initiate the operation.  The timing sequence consisted of the basket being dipped into each bath for a certain length of time.  Between each bath cycle, the basket would be raised above the solution, and an open pipe blow-off would remove excess liquid from the part with compressed air.   They complained that the parts were not getting dry enough, and cross-contamination was causing process problems.  The acid bath was becoming more neutral and the effectiveness of the etching was being sacrificed.  The rinse water was becoming more “soapy” after the cleaning bath and more acidic after the acid bath.  Overall, they had to replace every one of the bath solutions which caused shut-downs and extra expense.

From similar applications, I was able to recommend a great solution.  Because of the acidic solution and corrosive environment, I recommended two stainless steel Super Air Knives, model 110024SS.  They are manufactured in 303 stainless steel.  EXAIR also offers 316 stainless steel as well as PVDF for more acidic or caustic etching.  Instead of using the open pipes to blow off the parts, the customer could replace them with the Super Air Knives.  They can easily be mounted above the front and back of the basket, blowing at a downward angle toward the dip tank.  The two Super Air Knives would remove the liquid solution from the parts as well as the basket to put back into the same dipping tank.  The more solution that is removed, the less liquid that will transfer from one solution to the next; thus, reducing cross-contamination dramatically.

After installing the model 110024SS Super Air Knives in their system, they started to see a vast improvement in their etching process.  The etching acid was able to be used roughly 40% longer as compared to the prior method.  As an added feature, the Super Air Knives decreased the time to blow off the parts as they can be adjusted for optimum cleaning.  Less waste and faster production times were how the EXAIR Super Air Knives helped the customer above.  If you have a similar application and want to discuss how we can improve your dipping process, please speak to one of our Application Engineers.  We’ll be happy to help.

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

ROI – Is it Worth the Investment?

Any time you’re planning to purchase something, the return on investment (ROI) is an important thing to consider. Whether you’re considering buying new windows to improve on your heating and cooling costs, looking at replacing outdated appliances with newer and more efficient models, or purchasing an Intelligent Compressed Air Product, how quickly that product will pay for itself can help you to make the right decision.

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Last year, my wife and I purchased our first home. In the backyard, was a nice, big in-ground pool. While it was something we did look for, it requires a bit of maintenance during the summer months to keep the water clear and things running smoothly. Who wants to swim in a pool ridden with dirt, leaves, bugs, and debris floating around? Certainly not me, which meant I needed to spend some time brushing the sides of the pool and vacuuming to keep everything clean. For our first season, we elected to tackle this task manually. Not only was this time consuming, but it was also not very effective. To brush the sides and steps, skim, and vacuum took about 2 hours each time. I was doing this 2x per week to keep everything looking good. Over the course of a 15-week pool season here in Southwest Ohio, I spent approximately 60 hours just keeping the pool clean.

We were interested in the robotic pool vacuums available at our local pool supply store, but we balked at the initial price of them. After spending all this time doing it myself, I began to think that it would pay for itself relatively quickly (depending on how much I valued my own labor 😊). Allocating the cost of the robotic vacuum over the six-year life expectancy, as well as taking into consideration how much time I had spent cleaning the previous year, made this decision much more palatable. We went ahead, bit the bullet, and purchased one for this season. I must say, just two weeks in and my pool is cleaner than it ever was last year. We’ve only run it twice!! It only takes 5 minutes to connect and drop in. I reduced my time spent from 4 hours per week to 10 minutes per week. Consider me a happy consumer.

If you follow the EXAIR Blog, you’ll know that one of our primary focuses is saving customers money by reducing their compressed air operating cost. Recently, I wrote a blog post about a customer that replaced an inefficient solution with some EXAIR Super Air Knives. Let’s take a look and see how quick these knives were able to pay for themselves:

The previous solution consisted of (3) nozzles operated at 50 psig, consuming a total of 51 SCFM. This line was run continuously for (1) 8-hour shift, (5) days per week. The average cost for compressed air is $0.25 per 1,000 SCF (based on $0.08/kWh).

51 SCFM x 60 mins x 8-hours x $0.25/1000 = $6.12 per day

Replacing the inefficient nozzles with (3) Model 110003 Super Air Knives reduced the overall consumption to 17.1 SCFM when operated at 50 psig.

17.1 SCFM x 60 mins x 8-hours x $0.25/1000 = $2.05 per day

This led to a total savings of $4.07 per day, just by swapping out the inefficient product with the EXAIR Super Air Knives. So how quickly will they pay for themselves? Each Model 110003 Super Air Knife carries a list price of $199.00. Since we were using (3) on each line, their total investment per line was $597.00 USD.

$597.00/4.07 = 146.68 (147 days)

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Inefficient blowoff

On the 147th day (less than 30 weeks, based on a 5-day workweek), the Super Air Knives have paid for themselves. Afterward, that $4.07/day/line goes straight to the bottom line. You’ll be hard pressed to find many products that will pay for themselves in less than one year, but at EXAIR we see this day in and day out. Stop throwing your money out the window with inefficient compressed air solutions. Reach out to an EXAIR Application Engineer and see how quickly your blowoffs can start paying YOU.

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

Little things add up image courtesy of Nic McPhee via creative commons license

EXAIR’s Industry Leading Super Air Knife Saves You Money

One common application that we get calls for each and every day centers around maximizing compressed air efficiency. I recently got to work with a customer who was using an inefficient blowoff method and was looking to replace it with an engineered compressed air solution. They had a total of (8) extrusion lines, each with (3) modular-hose style flat nozzles installed. Before a cooling bath they had one nozzle remove some of the heat, then as the extruded material exits the water bath another (2) nozzles blowoff any residual water. They were maxing out their compressor’s peak operating capacity and pressure drops across the system were causing problems elsewhere in other processes.

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They were operating each of the flat nozzles at 50 psi using a total of 17 SCFM per nozzle. We first calculated how much air the current method was using. The extrusion lines were run for one full 8-hr shift per day:

17 SCFM/nozzle x 3 nozzles/line = 51 SCFM per extrusion line

51 SCFM x 60 mins x 8hrs x 5 days x 50 weeks = 6,126,000 SCF

The extrusion lines accommodated product that ranged from 1”-2.5” wide. They wanted one single solution to use across all different products. We settled on (3) of our 110003 3” Super Air Knives. Let’s take a look at the compressed air requirement for (3) 110003 Super Air Knives, also operated at 50 psig.

A Super Air Knife will consume 1.9 SCFM/inch when operated at 50 psig:

1.9 SCFM/inch x 3 inches (per knife) = 5.7 SCFM/knife

5.7 SCFM x (3) total knives = 17.1 SCFM

17.1 SCFM x 60 mins x 8hrs x 5 days x 50 weeks = 2,052,000 SCF

Total savings per extrusion line – 6,126,000 SCF – 2,052,000 SCF = 4,074,000 SCF

4,074,000 SCF x 8 extrusion lines = 32,592,000 SCF

By replacing the (3) inefficient nozzles with EXAIR’s Super Air Knives, a whopping 4,074,000 SCF of compressed air is saved each year. With (8) total lines, this equates to a total of 32,592,000 SCF of compressed air. Most companies will know the cost of their compressed air usage per CFM, but a cost of ($0.25/1000 standard cubic feet) is a good baseline to use.

($.25/1000 SCF) x 32,592,000 SCF = $8,148.00 USD

By replacing (3) inefficient nozzles across all (8) extrusion lines with EXAIR’s industry leading Super Air Knife, they were able to save a total of $8,148.00 per year. In as little as (6) months, the Super Air Knives will have already paid for themselves!!

If you’ve been maxing out your compressed air system, don’t necessarily assume you need to increase your overall capacity. Put in a call to an EXAIR Application Engineer and we can take a closer look at the ways your using your compressed air throughout the facility. By replacing some inefficient methods with an engineered solution, we can help you save air and money!

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

A Brief History of the Air Compressor

Essentially compressed air technology was first used with the knowledge of how to start a fire.  Humans learned that to get the fire started, blowing helped the process, healthy human lungs can generate approximately .02 to .08 bar or .3 to 1.2 PSI.

At the beginning of the metallurgical age (approximately 3000 B.C.) a higher volume of air than what human lungs could produce was required to the reach the temperatures required to melt and form metals such as copper, tin, lead, etc.  This need lead to the hand-operated bellows, the first mechanical air compressor.  Approximately 1500 years later the more efficient foot powered bellows was developed.

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The foot powered bellows was followed by water powered bellows and was the mainstay for more than 2000 years.  However as blast furnaces came into being the need for compressed air increased.  This lead John Smeaton in 1762 to design a water wheel that powered a blowing cylinder and this began to replace bellows.  In 1776 John Wilkinson developed an efficient blasting machine and this was the beginning for mechanically powered air compressors.

As time progressed the idea of transmitting energy via compressed air became acceptable.  This idea was demonstrated around 1800 when the newly invented pneumatic rock drill was used to tunnel 80 miles under Mt. Cenis to connect Italy & France by rail.  This was an extraordinary feat for the time and garnered global interest.  This event perpetuated great interest into pneumatic powered devices  and brought us the air powered motors, clocks and even beer dispensers!

While compressed air is capable of transmitting energy long distances and performing tremendous work it also referred to as the 4th utility in industrial plants due to its cost.  We at EXAIR have been promoting compressed air conservation and safety using highly engineered products for 35 years!  Our products wring the maximum of energy out of every SCFM fed to them by using air entrainment and the Coanda effect.  Not only are we conserving your compressed air we offer products that are quiet and can’t be dead ended which prevents air embolisms.

If you are interested in discussing conserving compressed air and/or compressed air safety, I would enjoy hearing from you.

Steve Harrison
Application Engineer

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Super Air Knife Helps You Use Compressed Air Efficiently

Sheet washing system

A sheet metal company made thin stainless steel sheets in their process.   Before the sheets were rolled up, it went through a washing system.  Two blower-type air knives were mounted after the wash cycle to remove the residual water from the surface.  They purchased the blower-style air knives under the belief that they would save money by not using compressed air.  They found out quickly that it was not a true statement especially when it comes to the total cost of ownership.

With the dirty environment at their facility, the inlet filter on the blower was getting plugged.  The blower motor would heat up from the filter being restricted.  After eight months of service, the blower motor failed due to excessive heat.  The replacement was very costly, and it created a production stoppage for an entire day.  The manufacturer of the blower-type air knife recommended that the filter should be changed every month instead of quarterly.  This recommendation increased the monthly budget for the blower system, but they did not want to replace the blower motor again.  Instead of a quarterly stop in production for maintenance, the washing system had to be stopped every month for filter change-out.   They decided to contact EXAIR to see if their concept of “saving money” with the blower-type air knife was valid.

To better explain the concept, I divided the comparisons into different categories explaining the details between the Super Air Knife and the blower system.

  1. Initial Cost:
    • Blower System – They are an expensive set up when you have to include a blower, ducting, and a knife. To have any flexibility, a control panel with a VFD will be needed.
    • Super Air Knife – It is a fraction of the cost. With their system above, we were roughly 1/4 the cost.  A capital expense would not be required for ordering two Super Air Knives to remove the water from the stainless steel sheets.
  1. Maintenance:
    • Blower System – The intake filter had to be changed every month, and the customer estimated a cost of $150.00 each. The motor and belt also had to be checked quarterly as a preventive maintenance.  Being that the blower motor is a mechanical device, the bearings and belts will wear and have to be replaced.  Without proper maintenance, things can break prematurely.  This customer had to already replace the motor in their system.
    • Super Air Knife – They do not have any moving parts to wear out, and they are not affected by the dirty environment. Only compressed air is needed to operate.  The maintenance requirement is to change the compressed air filter once a year.  The annual price for the replacement filter is less than $35.00.
  2. Compressed air usage:
    • Blower System – This device does not require any compressed air to operate, but it does use an electric motor. For this customer, they had a 7.5KW blower motor.  With the inherent designs of blower-type air knives, they have reduced blowing forces and turbulent air flows.  This combination required maximum power output on the 7.5KW blower motor.
    • Super Air Knife –With their unique design, it has one of the highest efficiencies in the market place. It can entrain 40 parts of ambient “free” air with every 1 part of compressed air.  With laminar flow and the power of compressed air, the Super Air Knives can be used at a much lower air pressure.  To compare with the electric blower motor above, the Super Air Knives only required 11KW of compressor power to operate.
  3. Noise:
    • Blower System – With the turbulent air flow, the blower units are very loud. It can have a sound level near 93 dBA.  If operators are working near the system, they would require PPE for hearing.  The cost for proper hearing equipment and the training for the operators will add more cost with using blower systems.
    • Super Air Knife – These units are very quiet. Even at an elevated pressure, the sound level is only 72 dBA at 100 PSIG.  This level is below the maximum noise exposure for hearing safety as marked in OSHA 29CFR 1910.95(a).

 

I tabulated the annual cost comparison and shared it with the customer to better explain the total cost of ownership.  After reviewing the information, they decided to try two pieces of the model 110230 Super Air Knife Kits.  When they replaced the blower-type air knives, the customer did share some additional information.  First, they were amazed at the ease of installation.  The blower-type air knives had to be electrically wired; floor space was sacrificed for the blower; the connection hoses were large and bulky; and the mounting was cumbersome.  The customer also noticed the amount of power that was created by the Super Air Knives.  They were able to increase the feed rates of the stainless steel sheets if they wanted and still keep the surface dry.  This gave them flexibility in their production system.  And of course, the maintenance time and cost were practically eliminated.  Compressed air is expensive, but if you use EXAIR products, you can use the compressed air very efficiently.  As noticed in the tabulation above, the total cost of ownership is very expensive for the blower-type air knives as compared to the Super Air Knives.  You can contact an Application Engineer at EXAIR if you want to discuss further the benefits of using the Super Air Knives.

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

Fluidics, Boundary Layers, And Engineered Compressed Air Products

Fluidics is an interesting discipline of physics.  Air, in particular, can be made to behave quite peculiarly by flowing it across a solid surface.  Consider the EXAIR Standard and Full Flow Air Knives:

Compressed air flows through the inlet (1) to the Full Flow (left) or Standard (right) 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 serve to optimize the entrainment of air (4) from the surrounding environment.

If you’ve ever used a leaf blower, or rolled down the car window while traveling at highway speed, you’re familiar with the power of a high velocity air flow.  Now consider that the Coanda effect can cause such a drastic redirection of this kind of air flow, and that’s a prime example of just how interesting the science of fluidics can be.

EXAIR Air Amplifiers, Air Wipes, and Super Air Nozzles also employ the Coanda effect to entrain air, and the Super Air Knife employs similar precision engineered surfaces to optimize entrainment, resulting in a 40:1 amplification ratio:

EXAIR Intelligent Compressed Air Products such as (left to right) the Air Wipe, Super Air Knife, Super Air Nozzle, and Air Amplifier are engineered to entrain enormous amounts of air from the surrounding environment.

As fascinating as all that is, the entrainment of air that these products employ contributes to another principle of fluidics: the creation of a boundary layer.  In addition to the Coanda effect causing the fluid to follow the path of the surface it’s flowing past, the flow is also affected in direct proportion to its velocity, and inversely by its viscosity, in the formation of a boundary layer.

High velocity, low viscosity fluids (like air) are prone to develop a more laminar boundary layer, as depicted on the left.

This laminar, lower velocity boundary layer travels with the primary air stream as it discharges from the EXAIR products shown above.  In addition to amplifying the total developed flow, it also serves to attenuate the sound level of the higher velocity primary air stream.  This makes EXAIR Intelligent Compressed Air Products not only as efficient as possible in regard to their use of compressed air, but as quiet as possible as well.

If you’d like to find out more about how the science behind our products can improve your air consumption, give me a call.

The Case Is Mounting For Stay Set Hoses

So, you’ve selected a quiet, efficient, and safe EXAIR Super Air Nozzle for your blow off application – good call! – and now you’re thinking about how to install it.  Sometimes, it’s as simple as replacing whatever you’re using right now:

EXAIR Intelligent Compressed Air Products have common NPT (or BSP) connections, making for easy replacement of most any existing threaded device.

Or maybe you’re using an open end blow off…in which case, you’re just an adapter away:

EXAIR Super Air Nozzles are quick and easy to install on existing copper tube, via a simple compression fitting.

Perhaps, though, it’s a new installation, or the existing supply lines aren’t suitable for one reason or another.  In those cases, we’ve still got you covered…consider the EXAIR Stay Set Hose:

Precise aiming and location is a breeze with EXAIR Stay Set Hoses.

Available in a variety of lengths from 6″ to 36″, they’re positionable, and re-positionable with a simple bending action.  They won’t kink or easily fatigue like copper tubing.  The supply end is 1/4  MNPT, and you have your choice of 1/4 MNPT or 1/8 FNPT on the other end, depending on which Super Air Nozzle, Air Jet you need to use it with.

We also offer Blow Off Systems, which are a combination of a specific Air Nozzle (or Air Jet,) fitted to a Stay Set Hose:

Model 1126-9262, for example, is a Model 1126 1″ Flat Super Air Nozzle with a 9262 Stay Set Hose.

For added convenience and ease of installation, these products can also come with a Magnetic Base:

Mag Bases come with one or two outlets. Stay Set Hoses come in lengths from 6″ to 36″.

Stay Set Hoses are also available with a variety of our Soft Grip Safety Air Guns, and they make the GEN4 Stay Set Ion Air Jet one of our most popular Static Eliminator products.  They’ve even been successfully applied with small Air Amplifiers and Air Knives…with certain limitations (spoiler alert: trying this with a 108″ Super Air Knife is going to be a definite “no.”)

Model 110003 3″ Aluminum Super Air Knife with 6″ Stay Set Hose & Magnetic Base.

From the beginning in 1983, EXAIR’s focus has been on being easy to do business with, and that goes from our friendly customer service to our expert technical support to our 99.9% on-time shipments (22 years and running) to designing our engineered products and value-added accessories with efficiency, safety, and ease of installation in mind.  If you want to find out more, give me a call.