Vacuum Generator System Selection – EXAIR E-Vacs

E-Vac Vacuum Generators are a highly efficient, versatile compressed air vacuum pump. Their versatility allows them to be adapted to many applications such as pick and place, clamping or vacuum forming. They’ve also been used in more unique applications like wood veneer pressing and basketball deflation.

EXAIR manufactures (3) types of E-Vacs – Low vacuum generators for porous materials, like cardboard, generating up to 21″ Hg with vacuum flows as high as 18.5 SCFM. Our high vacuum generators, designed for use with non-porous materials like glass or steel sheets, produce vacuum levels up to 27″ Hg and up to 15.8 SCFM of vacuum flow. The adjustable generators provide flexible vacuum performance, up to 25″ Hg and 81 SCFM,  which can be easily adapted to meet the application.

EXAIR E-Vacs provide instantaneous vacuum response, and are engineered for high efficiency to minimize air consumption.

 

When making a selection, there are a few key areas you want to consider:

Is the material porous or non-porous?

  • This will allow you to select the proper type of vacuum generator to fit the application and the type of vacuum cup best suited for the process.

 

What is the weight of the part and how will it be lifted?

  • If the part is being lifted where the vacuum cups will be positioned horizontally, like on top of a sheet of glass, you want to use a safety factor of 2 times the actual weight of the part. In processes requiring the cups be positioned vertically on the part, such as picking up a sheet of plywood and hanging it on an overhead conveyor, a safety factor of 4 would be used.

 

How many Vacuum Cups do I need?

  • Consider the quantity and placement to evenly distribute the weight for safely moving the material.
  • Depending on the maximum vacuum the generator produce, how much weight can each cup lift?
  • Make the cup selection per the following chart

 

Once you have selected the type and number of cups needed, you can then begin to look at which additional accessories items you might need.

  • Filters – supplying clean, dry air is key for maintaining optimal performance. An automatic drain filter  can be used to remove any water or contaminants in the supply line. If there is oil present, consider using an Oil Removal Filter.
  • Mufflers – help to reduce the noise level without restricting the airflow. We offer 2 different styles – Standard and Straight Through. Standards mufflers are a good choice where the supply air is clean and dry. These mufflers can only be used with the porous and non-porous generators. The Straight Through mufflers reduces sound levels by up to 26 dBA and are the better choice in processes where dirt or particulate may be present.
  • Tubing and Fittings – polyurethane tubing is available in 10′ sections up to 50′ for processes requiring the vacuum cups be placed in a location that wouldn’t allow for direct mounting to the NPT vacuum port on the generator or where multiple cups are needed. You want to keep the length of tubing as short as possible though for effective pickup and release time.
  • Check Valve – will maintain vacuum on the load if the supply pressure were to drop or be lost during operation.

For additional assistance selecting the proper E-Vac and accessories for your process, please contact an application engineer at 800-903-9247.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

Super Air Wipe Controls Coating Thickness On Tubing

A large manufacturing company called looking for a better solution to control the thickness of a curing agent being applied to the outside of tubing used in the automotive industry. The tubing is formed in an extruder and travels through a liquid cooling chamber and then air dried. After the tubing is dried, it is sent to a spray chamber where the curing agent is applied to the exterior. On the exit side of the spray chamber, the customer had installed several flexible air lines placed around the perimeter of the tubing to blow air across the surface to help control the coating thickness. This worked somewhat but they were seeing an increase in the amount of rejected material as the air pattern was sporadic and uneven, which caused streaking and dry spots in certain areas of the tubing. They reviewed our web site and familiarized themselves with our Air Wipes but were unsure of the best design and size to fit their need so they reached out for assistance.

After further discussing the process, their tube O.D. sizes range from 3/8″ – 1/2″, making our 1″ Air Wipe the ideal solution. As far as the design, the Standard or Super Air Wipe, I recommended they use our Model # 2451 Super Air Wipe kit due to the aluminum construction and stainless steel wired braided hoses being able to withstand the potential temperature in the area of 200°F. The kit includes a filter separator to remove any water or contaminants in the supply and a pressure regulator which would allow them to control the flow and force of the exiting air, to help “dial” it in to fit the demand of the application.

Super Air Wipe is available in sizes from 1/2″ up to 11″ in Aluminum construction and up to 4″ in Stainless Steel construction.

 

EXAIR Air Wipes features a split design, which can easily be clamped around the material, to provide a 360° uniform airflow, perfect for treating the surface of round shapes, like extruded tubing. If you have an application where you are needing to dry, cool or clean the outside of a pipe, hose or cable, contact an application engineer for help making the best product selection.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

There’s More Than 1 Way To Blow Some Air

Just today I spoke with a customer who is threading the ends of pipes and needs to blow the coolant and chips out of the threads.   The pipes range from 4″ to 9 – 5/8″ Diameters.  They are all threaded then fed into a trough and pushed down line to the next operation.

PEO ACWA
A machine with an out-feed roller conveyor similar to the pipe threading machine mentioned.

The photo above is not the exact machine but you can see where if this was used to process piping the different diameter pipes would all sit at the same level.  One option could be to use a Super Air Wipe  for this application but then the smaller diameters would not pass through the center of the Air Wipe, instead they would pass through the bottom half of the airflow which may not give optimal performance. Instead, I suggested to use 4 of our 6″ Super Air Knife kits and 2 of our Electronic Flow Control units.

 

2 - 110006 - 6" Aluminum Super Air Knives coupled together w/  a 110900 SAK Connector Kit
2 – 110006 – 6″ Aluminum Super Air Knives coupled together w/ a 110900 SAK Connector Kit

I  suggested that we make two pairs of knives for this blowoff setup by coupling two of the 6″ Super Air Knives together.  Once they are coupled together like is shown above, we could mount the two coupled air knives vertically along the trough and blowing at a 45° angle toward the center of the conveyor.  The plumbing of the two bottom knives will be to one EFC while the top two knives will be plumbed to the other.    The sensors will then be set up at two different heights, lower knives to sense the bottom of the pipe and the upper knife sensor will be set just above the bottom 6″ knife.

The reason for using 4 – 6″ Super Air Knives and 2 EFCs instead of 2 – 12″ Super Air Knives and 1 EFC is to save the most compressed air possible.   By enabling them to turn the top two 6″ Super Air Knives off automatically when they are running below a 6″ diameter pipe.  Then when a larger pipe is processed the top knives will also kick on with the lower knives and provide a uniform blowoff of the product.

So if you have multiple sizes of product being processed on the same line and don’t think any one solution will work, contact us and see if we can’t come up with our own recipe.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Machine image courtesy PEO ACWA Creative Commons

 

3 Common Mistakes in Your Compressed Air System

Every day I speak with engineers who are having trouble using compressed air products. A common problem they have is not providing an adequate air supply to their unit. I go through a basic troubleshooting technique to ensure that their pressure and flow rate is adequate. I ask them to install tee on the inlet to the compressed air product in order to install a pressure gauge right at the inlet to the pipe. This allows us to know exactly what pressure we are supplying to the product. Customers are always surprised how the gauge on the compressor or the regulator may read 120 PSIG, but the gage on the inlet to the compressed air product is significantly less.

Last year, my colleague, Russell Bowman, made an excellent video showing how the inlet pressure at the knife will have a significant impact on the performance of the Super Air Knife.  In the video, he changes the length and ID of the compressed air supply to illustrate the difference a proper supply line will have on the performance of a compressed air products.

Not providing adequate air supply is commonly caused by these three mistakes, when plumbing compressed air systems.

1. Incorrectly Sized Piping – This can be the single biggest problem. A lack of planning before installing a compressed air product. Not all compressed air systems are created equal. Though a 1/4″ shop air hose may work for a number our products, some of our products require a larger air line because they require more volume of air to be effective. We often speak with customers an illustrate this problem by stating small air lines are like trying to feed a fire hose with a garden hose – there simply is not enough volume to create the pressure necessary to reach the fire, or solve the application in our scenarios. We publish the flow rates for all of our products and make inlet pipe size recommendation in the installation and maintenance guide furnish with the products so you may avoid this common problem. We also have air data tables in our Knowledge Base or  you may consult an application engineer who will be happy to make the proper recommendation.

2. Quick Disconnects – These handy connectors are great when operating a brad nailer, or a small blow gun, but the small through diameter can severely limit the flow rate into a long air knife, large diameter air operated conveyor, or big vortex tubes.  Due to this fact it is strongly advised to use threaded fittings or over-sized quick disconnects.

3. Adding extra hose or pipe – Extra hose is never a bad thing, right? No, an extra 30 feet of air hose can significantly drop the pressure of a compressed air system. 20 feet of ½ Pipe can flow 70 CFM with a 5 PSI pressure drop.  50 feet of ½” pipe will only flow 42 SCFM with the same 5 PSIG pressure drop. Keep your hose or pipe lengths to a minimum to improve the volume of air you can deliver to a compressed air product.

Dave Woerner
Application Engineer
DaveWoerner@EXAIR.com
@EXAIR_DW