Month: August 2016

Super Air Wipe Helps in Testing Wire Insulation

Published on by John BallLeave a comment

A cable manufacturer sent me videos of his operation as they needed to improve their efficiency in removing water from the surface of the insulation. Their system began with the insulation being applied to the outside of the wire cable, being dipped into a water trough to harden the insulation, travel through the blow-off device, then into a spark tester.  The spark tester checks the insulation for imperfections.  Also called a hi-pot tester (high-potential), a high voltage is used to create a large potential across the insulation.  Any defects in the insulation can be detected, but it is very sensitive to surface contamination.  Being that the water is very conductive, it had to be removed or it would give a false result.  They were using a home-made circular blowing device (photo below) to blow the water off after dipping.  When they were at the higher line speeds, the blow-off device was not removing the water completely from the insulation.  This would cause the spark tester to alarm and stop production.

Home-made Air Wipe
Home-made Air Wipe

This company makes cables ranging from 10mm to 25mm in diameter. With various types of voltage ratings on the wire, the insulation was made with different types of materials and thicknesses.  So, the line speeds could range from 20 to 200 meter/minute.  Being that they needed a better way to remove the wire, they searched for wire and cable blow-off devices. They came across the Super Air Wipe from EXAIR.  The design of the Super Air Wipe blows compressed air at a 30 degree angle toward the center in a 360 degree air pattern, just like a cone.  It uses the Coanda effect to entrain as much ambient air into your compressed air to maximize force and efficiency.  Because of the variations in diameters and speeds, I suggested two different sizes, the model 2401 and model 2402.  The model 2401 has an I.D. of 1” (25mm), and it would work best with the cable diameters of 15mm and under.  The model 2402 has an I.D. of 2” (51mm), and it can handle the cables that are above 15mm in size. This pair of Super Air Wipes would give the customer the most consistent results no matter what line speeds that they ran.  With the split design of the Super Air Wipe, it makes it easy to clamp around the cable and change from one size to the other.

Super Air Wipe
Super Air Wipe

As they removed their home-made unit and attached the Super Air Wipes, they noticed a few things. The spark tester stopped getting false alarms.  This made the production process run smoother; even at the faster line speeds.  They noticed that the Super Air Wipe was much quieter.  With a decibel rating of 77 dBA, the nearby operators were very happy with this choice.  Also, they noticed that the Super Air Wipes used much less compressed air.  Because the design utilizes the “free” ambient air, less compressed air is required.  This would save them a lot of money in their electric bill and the stress on the compressed air system.  If your company needs to blow off cables, hoses, pipes, or any cylindrical type parts, the Super Air Wipe could be a great product for you.

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

Observations By The New Guy

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As the junior member of the EXAIR Application Engineer Team, I have a fresh view on the differences in the EXAIR Business Model versus my prior places of employment.

EXAIR has 1000’s of items in stock, ready for same day shipment with orders received by 3 pm EDT. Here, a long lead time item is considered 1 week, as opposed to 20+ weeks, that I had previously quoted at other employers.  Imagine needing something quickly and then finding out it would be 20 weeks for delivery. Everything in the EXAIR catalog is a stock item, and ready for your order.

Our year to date on time delivery rate of > 99.9% is amazing, and even more incredible is the streak of 20 years of shipping complete, on time, and correct orders of over 99.9%.  Nothing was more frustrating than starting the day with calls and emails to customers telling them their order is going to be late, and the wasted time for everyone in determining the reason, who was at fault, what the new ship date will be and the general disdain caused by such interactions.  I sure don’t miss that part of the work day, freeing me up to truly service the customer.

The last item that truly separates EXAIR as not only an employer but a vendor is, the EXAIR Guarantee. Every application is different and it is the Application Engineer’s job to understand the application and best identify the right EXAIR Intelligent Compressed Air Product® to provide the benefit.  For those applications that are what we might say, on the ‘fringe’ of the capabilities, the 30 Day Guarantee is a great way to perform a real world test of the product in the actual application environment.  If it doesn’t meet expectations, then we’ll gladly take it back for a full refund.

30 Day Guarantee

In my time here at EXAIR, every day offers exciting new ways to provide service to our customers.  Each new phone call, email, and chat is an opportunity to execute the EXAIR way of business and provide the high level of performance our customers have come to expect, and can rely on, from the whole team here.

Brian Bergmann
Application Engineer
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EXAIR Webinar: Intelligent Compressed Air Solutions For OSHA Compliance

Published on by exaircorpLeave a comment

bWebinar_186x133blog
On September 13th, 2016 at 2 PM EDT, EXAIR will be presenting a FREE webinar. During the short presentation, we will be covering the OSHA Standards for the safe use of compressed air when used for cleaning purposes.

The first topic we will discuss will pertain to the OSHA Standard 29 CFR 1910.242 (b) limiting the outlet pressure of an open pipe, tube, air gun, nozzle, etc. to less than 30 PSIG. When dead ended against the skin, air pressure above 30 PSI, can introduce air flow into the body, otherwise known as an air embolism. An air embolism can be an extremely dangerous condition which can cause serious injury, such as a stroke or possibly death.

Secondly, we will discuss the OSHA Standard 29 CFR 1910.95(a) for permissible noise exposure levels. In the Standard, OSHA has set exposure limits (in hours) for varying sound levels (dBA). When employees are subjected to sounds in excess of the limiting guidelines, some type of engineered controls should be used to reduce the sound level exposure. We will provide some useful statistics, as well as help you identify some common culprits found in many processes.

Lastly, we will show you how EXAIR provides engineered solutions that address both dead end pressure and noise exposure levels. All of EXAIR‘s blowoff devices feature some type of relief so if the exhaust airflow were somehow blocked or pressed against the skin, there is always a safe path for the air to exit, so the discharge pressure never exceeds 30 PSI. In addition, we will explain how our products reduce wind shear, ultimately lowering the sound level, save energy and help you gain OSHA compliance to avoid costly fines.

CLICK HERE TO REGISTER

Justin Nicholl
Application Engineer
justinnicholl@EXAIR.com
@EXAIR_JN

 

 

 

Adjustable Spot Cooler Easily Cools Aluminum Plates

Published on by Lee Evans2 Comments
Cooling Unit- Iso View
This setup needed a method to cool a 400g aluminum plate (click for larger view)

When we work with our customers about cooling applications, we usually approach them in one of two ways – either with a need to cool down to ambient temperatures, or a need to cool below ambient temperatures.  If we only need to cool to ambient conditions, we can use Super Air Amplifiers, Super Air Knives, Air Nozzles, or Safety Air Guns.  But, if we need to cool below ambient temperatures, we have to use a vortex-based technology such as a Vortex Tube, Adjustable Spot Cooler, Mini Cooler, Cold Gun, or Cabinet Cooler.

One of our overseas customers reached out to me with a need to cool a 400g aluminum plate from 80°C (176°F) to 27-30°C (80-86°F) over the course of about 40-60 seconds.  They needed something repeatable, dependable, and compact, so we explored a Vortex Tube-based solution.

heat load calc process
Process flow for calculating required air volume in a cooling application (click for larger view)

We’ve shown airflow calculations for our Air Amplifiers in the past, and I used the same rationale (shown above) to determine the required air volume to cool this application.  In these types of applications, we derive a ΔT value between the desired ending temperature of the material and the temperature of the air which will be blown onto the material.  So, for this application, we have a desired end temperature of 30°C, and we have considered an outlet temperature of 0°C from a Vortex Tube device.

After determining all the required values, I performed the calculations shown below to arrive at a volume flow of 15.8 CFM.

Cooling calculations for ASC in aluminum plate application
Calculations for determining the required air volume in this application (click for larger view)

In uncovering that the ambient conditions may change, and sharing that these changes could create variance in the required air volume, the end user opted for two model 3925 Adjustable Spot Coolers to provide the required cooling.  Just like Vortex Tubes or Cold Guns, the Adjustable Spot Coolers allow for repeatable delivery of very cold air to the application, but they also have the additional benefit of easy “fine tuning” through the adjustment valve on the hot end of the unit.

Cooling Unit - Details
The cooling unit for the aluminum plates (click for larger view)

The cold air created by the Adjustable Spot Coolers are fed to the nozzles shown above in red.  By supplying an adequate volume of cold air at the right temperature, the problem in this application has been easily solved.

If you have an application with a heating concern, give us a call.  We’re happy to help.

Lee Evans
Application Engineer
LeeEvans@EXAIR.com
@EXAIR_LE