Super Air Knives Replace Inefficient Blowoff Method on Extrusion Line

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.

KIMG0161

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

Super Air Knife Replaces a Blower-type Air Knife and Saves Money Annually

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

Video Blog: EXAIR’s Universal Air Knife Mounting System

Using EXAIRS Universal Air Knife Mounting System greatly ease’s the installation of all Air Knives (Except PVDF).  It will save you the time and expense of designing and fabricating your own mounting system which will maximize your uptime and keep your staff focused on key plant tasks!

Please note the table below that highlights the recommended number of the Universal Air Knife Mounting System to use for the various length of Air Knives.

Length Of Air Knife Number of UAKMS
3″ – 18″ 1
24″ – 54″ 2
60″ 3
72″ – 95″ 4
96″ – 108″ 5

If you would like to discuss Universal Air Knife Mounting System, Air Knives or any EXAIR compressed air product, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer

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Intelligent Compressed Air: Utilization of the Coanda Effect

Henri Coanda was a Romanian aeronautical engineer most known for his work developing what is today known as the Coanda effect. The Coanda effect is the propensity of a fluid to adhere to the walls of a curved surface. A moving stream of fluid will follow the curvature of the surface rather than continuing to travel in a straight line.  This effect is used in the design of an airplane wing to produce lift. The top of the wing is curved whereas the bottom of the wing remains straight. As the air comes across the wing, it adheres to the curved surface, causing it to slow down and create a higher pressure on the underside of the wing. This  is referred to as lift and is what allows an airplane to fly.

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The Coanda effect is also the driving force behind many of EXAIR’s Intelligent Compressed Air Products. Throughout the catalog you’ll see us talking about air amplification ratios. EXAIR products are designed to take advantage of this phenomenon and entrain ambient air into the primary air stream. Compressed air is ejected through the small orifices creating air motion in their surroundings. Using just a small amount of compressed air as the power source, Super Air Knives, Air Nozzles, and Air Amplifiers all draw in “free” ambient air amplifying both the force and the volume of airflow.

Entrainment
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.

Super Air Knives provide the greatest amount of air amplification at a rate of 40:1, one part being the compressed air supply and 40 parts ambient air from the environment. The design of the Super Air Knife allows air to be entrained at the top and bottom of the knife, maximizing the overall volume of air. Super Air Nozzles and Super Air Amplifiers also use this effect to provide air amplification ratios of up to 25:1, depending on the model.

HowItWorks
Air Amplifiers use the Coanda Effect to generate high flow with low consumption.

The patented shim design of the Super Air Amplifier allows it to pull in dramatic amounts of free surrounding air while keeping sound levels as low as 69 dBA at 80 psig! The compressed air adheres to the Coanda profile of the plug and is directed at a high velocity through a ring-shaped nozzle. It adheres to the inside of the plug and is directed towards the outlet, inducing a high volume of surrounding air into the primary air stream. Take a look at this video below that demonstrates the air entrainment of a Super Air Amplifier with dry ice:

Utilizing the Coanda effect allows for massive compressed air savings. If you would like to discuss further how this effect is applied to our Super Air Knives, Air Amplifiers, and Air Nozzles give us a call. We’d be happy to help you replace an inefficient solution with an Engineered Intelligent Compressed Air Product.

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

Super Air Knife Helps Plastic Injection Molder

EXAIR commonly works with plastic injection molding companies. They produce top quality plastic parts from both commodity and engineering-grade resins for many diverse industries. The customer reached out to us with a problem. A mold that they were running was having some issues. The parts were not releasing and ejecting properly, causing the need to use a mold release, which was slowing down the process by a manual operation to the process.  Also, the parts were seeing push pin marks, causing cosmetic issues with the parts.  The customer wanted to explore using compressed air to blow the parts free.

Plastic Injection Mold
Typical Plastic Injection Mold

Based on the mold size and layout, a pair of 12″ Super Air Knives was installed.  The knives are oriented to blow straight down along the face of the mold, one knife per part tree.  The strong laminar flow of air hits the parts causing them to release and drop without the use of release agents.  Also, the push pin marks are within normal standards, eliminating the the cosmetic concerns.

gh_Super Air Knife 750x696

This is just one example of how intelligently using compressed air can help improve a process.  By using air knives for wide areas or using a 1″ Flat Super Air Nozzle for very small parts, or anywhere in between, we can help to solve your part ejection issues and make your process run better, faster, and with higher quality.

1126
1″ Flat Super Air Nozzle with Changeable Shims

If you would like to talk about Super Air Knives, Flat Nozzles or any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Injection Mold Photo – “Creative Commons Injection Mold” by Mitch Barrie is licensed under CC BY-SA 2.0

Super Air Knife And Plumbing Kits = Best Performance And Easy Installation

 Of the 3 styles of Air Knife offered by EXAIR, the Super, Standard and Full-Flow, the Super Air Knife is our most efficient, in regards to compressed air usage. Using a 40:1 amplification rate of entrained ambient air to compressed air consumed, it uses only 2.9 SCFM per inch of knife length when operated at 80 PSIG, while producing a low sound level of only 69 decibels (the quietest on the market today). The Super Air Knife provides  an even laminar flow of air across the length of the knife and is available in single piece lengths from 3″ up to 108″ in aluminum, 303 stainless and 316 stainless as well as up  to 54″ in PVDF (Polyvinylidene Flouride) construction for applications where aggressive chemicals may be present. 1/4″ FNPT air inlets are available on each end as well as on the bottom of the knife.

Aluminum, Stainless Steel and PVDF Super Air Knives

For Super Air Knives 24″ and longer, you need to plumb air to multiple inlets to maintain an even airflow. Our available Plumbing Kits includes the properly sized hose or pipe and fittings, to not only save valuable time looking for these parts yourself but also eliminates the potential of using undersized lines which will reduce the performance of the Super Air Knives.

For Super Air Knives in aluminum construction, the Plumbing Kits include cut to length PVC compressed air hose and the required brass fittings.

Plumbing Kit for aluminum Super Air Knives

The Plumbing Kits for our stainless steel and PVDF Super Air Knives, include 316ss cut to length pipe as well as 316ss fittings.

Plumbing Kit for 303ss, 316ss and PVDF Super Air Knives

The Super Air Knife is the ideal choice when looking to treat wide-area applications, like cleaning a conveyor or drying parts after a wash process. For help selecting the best product to fit your process, contact one of our application engineers for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

Super Air Knife Reduces Defects and Lowers Freight Costs

The EXAIR Super Air Knife – high force with precision flow

An Argentine food manufacturer recently reached out to our distributor in Buenos Aires (AYRFUL) to discuss a potential application for EXAIR products.  The need became clear when a packaging line for soon-to-be-frozen food began experiencing problems with excessive water on the surface of the packages.  In this process, the packages are rinsed to remove any unwanted debris, and then sent into a large freezer before distribution to local groceries.

The excessive water on the packages would become ice, which would fuse the packages together when stacked in boxes for transporting to retail centers.  This fusing caused rips in the packaging when they were separated, thereby creating unsellable goods, ultimately leading to returns for this manufacturer.  And, the residual water also increased the total weight of the packed packages, enough to increase the actual weight when bulk packed.  This increase in actual weight led to an increase in freight costs from their courier.  So, this manufacturer needed a way to remove the residual water, reduce defects and returns, and simultaneously lessen the freight cost.

Model 110048 Super Air Knife (inside red box) blowing off residual water after rinsing and before freezing. See note on plumbing below.

The solution they found was a 48” EXAIR Super Air Knife, model 110048, mounted using (2) Universal Air Knife Mounting Kits.  The Super Air Knife in this application provided a precision airflow to blow off the water from the top of the packages, after rinsing and before freezing.  Removing the water at this stage, as shown above, eliminated the problem of fused packages, rejected products, returns, and increased freight.  And, the Super Air Knife was able to do this at a low operating pressure, fed from a single compressed air inlet.

(Note – EXAIR recommends plumbing multiple compressed air inlets for Air Knives longer than 18”.  For this model, 110048, we recommend compressed air be supplied to (3) compressed air inlets.  Plumbing less inlets will reduce the compressed air flow into the knife, which reduces possible operating pressure.  In this case, the lower operating pressure was acceptable, however, we still recommend to plumb (3) compressed air inlets on a 48” Super Air Knife.)

Plumbing specifics aside, this solution still brought tremendous value for the customer.  They were able to solve the root cause of a multi-faceted problem with an engineered solution.  If you have an application in need of an engineered solution, contact an EXAIR Application Engineer.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com