Super Air Wipe Helps in Testing Wire Insulation

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

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