A manufacturer of special pipes sent me a video of their operation. After the pipes were extruded, they would run them through a wash system to cool and harden them. After the wash system, they needed to remove the excess water from a 3” (76mm) diameter tube at a speed of 50 feet per minute (15 meters per minute). They were using a blower system to blow the water off the pipe with a series of blower air knives. The company was looking to increase the speed of the lines to be more productive and profitable. As they did some trial runs, they were only getting around 75% dryness. They needed a better way to get the pipes dry before ink printing.
This company makes plastic pipes ranging from 2” (51mm) to 8” (203mm) in diameter. When they searched for pipe and tube blow-off devices, they came across EXAIR and our Air Wipe product line. The design of the EXAIR Standard Air Wipe blows compressed air at a 30-degree angle toward the center in a 360-degree air pattern. It uses a Coanda profile to maximize the entrainment of ambient air into the compressed air stream to produce a strong force. As a non-contact wiping device, the Standard Air Wipe is very efficient and powerful. EXAIR also offers the Super Air Wipes for more stringent applications. You can read more about them here: What’s So Super About EXAIR’s Super Air Wipe?
For this application, I recommended the model 2484 4” Standard Air Wipe Kit. This kit includes our Standard Air Wipe, a Filter Separator, a Regulator, and a Shim Set. With a ½” or 13mm clearance, it gave ample room to allow the 3” (76mm) pipe to travel through without touching and to allow for ambient air to be entrained. The Filter Separator will remove bulk liquids and debris from the compressed air to keep the unit performing optimally and to keep the pipe from getting dirty. The Pressure Regulator is used to control the amount of force. This helps to not overuse the amount of compressed air required for the cleaning. With a Pressure Regulator, you can make fine adjustments to get the proper amount of force on your target, while the shims in the Shim Set will give you coarse adjustments. With the Pressure Regulator and Shim Set together, you can “dial in” the correct amount of force required for the different speeds. The Standard Air Wipe Kits will give you the most versatility in your system to optimize the 360-degree blow-off.
As the customer removed the original blower unit and attached the Standard Air Wipe to their compressed air system, they noticed some great things. The speed of production was increased by about 10%, which matched the maximum speed of the machine. The water removal from the surface was nearly 100%. They also noticed that the Standard Air Wipe was much quieter – near 82 dBA at 80 PSIG (5.5 bar). The nearby operators were very happy with this choice, as the blower-type system was very loud. And, with no moving parts, the Air Wipe did not need the same maintenance requirements as the blower system did, and it used a much smaller footprint. Also, we use a split design to mount the Standard Air Wipe around the outside of the pipe without cutting into the extruded lengths.
Here are some comparisons with the EXAIR Standard Air Wipes to a blower-type system.
- Cost:
- Blower System: Blower-type air knives are expensive to set up. They require a blower, knives, and large (3″ – 4″ diameter) ducting. To have any flexibility, a control panel will be needed with a VFD to control the speed of the blower.
- Standard Air Wipe: It is a fraction of the cost. With their system, we were roughly 1/10 the cost, even with the kit. No capital expense report would be needed.
- Installation:
- Blower System: The customer stated that it took them a week to install the entire system before they were able to operate. They had to run electrical wires, controls, and ducting, and they even had to change their system design to accommodate the blower size.
- Standard Air Wipe: They mounted the filter and the regulator on the conveyor and ran tubing to the Standard Air Wipe. Even with a fabricator making a bracket to fit the Standard Air Wipe around the pipe, they had the system up and running in less than two hours.
- Size:
- Blower System: The footprint of the blower is large, and it takes up floor space. The 3” ducting had to be run to an oversized air knife. With the congestion in the area, it was difficult to optimize the position and the blowing angle to adequately dry the pipes.
- Standard Air Wipe: With its compact design, the Super Air Knife packs a large force in a small package. It has a small footprint that fits around the pipe. It only required a ¼” NPT compressed air line to supply the compressed air. It opened up the floor space as well as the general area.
- Maintenance:
- Blower System: The blower filter had to be changed regularly, and the system had to be checked for preventative maintenance. Being that the blower motor is a mechanical device, the bearings will wear, and the motor will fail over time. These items need to be checked quarterly as a PM, which increases the cost of running the system.
- Standard Air Wipe: No moving parts to wear out. The only maintenance would be to change the filter once a year.
- Versatility:
- Blower System: They did have a VFD to control the blowing force. But it was still very limited. With the increase in pipe speed, it was beyond the maximum capacity of the blower.
- Standard Air Wipe: With a regulator and the shim set, the blowing force can be controlled easily, from a breeze to a blast. With their application, the customer only required 40 psig with a standard 0.002” shim to clean and dry the pipes. They had the option to adjust the regulator or change the shim to get the appropriate amount of blowing force with the different line speeds.
- Quiet:
- Blower System: With the blower and turbulent air flow, the units are very loud. It had a sound level near 93 dBA, and with the operators working around the system, they needed PPE for hearing.
- Standard Air Wipe: These units are very quiet. As mentioned above, the decibel level is only 82 dBA at 80 PSIG (5.5 bar). At 40 PSIG (2.8 bar), the sound level is much lower. This was very nice for the operators to work around as it wasn’t a constant noise nuisance, and it was below the OSHA limit for PPE.
With the creation of the EXAIR Standard Air Wipes, uniform cleaning, cooling, and blowing around the outside of parts is a simple task. You don’t have to worry about too many nozzles to target the circumference or fabricated blow-off air knives that will waste time and money. At EXAIR, we offer a 30-day unconditional guarantee for U.S. and Canadian customers. This customer used the 30-day trial to try the Standard Air Wipe. After the testing, they purchased the model 2491 11” Standard Air Wipe Kit for their largest pipe. You can order them from our website at http://www.EXAIR.com or call us at 800-903-9247. If you need help selecting the proper size for your application, you can contact an Application Engineer at EXAIR for help.
John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb