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

 

Help with Choosing an E-Vac Vacuum Generator

This is a pretty common question when it comes to Vacuum Generator use in pick-and-place application, and although we can’t boil it down to a simple table & formula based on mass (like we can with the Vacuum Cups themselves,) we can usually hone right in on it, if we have enough details of the situation. And, if questions remain, we can always test one to find out…we’ve got an Efficiency Lab.

That’s what I did, first thing this morning. I had the pleasure of speaking with a robotics instructor at a vocational school yesterday…his class was building a robot to enter in a competition, and one of the operations it needs to accomplish is picking up a golf ball and carrying it a certain distance.  This sounded like a great application for a small E-Vac Vacuum Generator, and, considering the potential leakage at the Vacuum Cup face from the dimples on the golf ball, my first instinct was to consider our Model 810002M E-Vac Low Vacuum (Porous Duty) Generator w/Muffler, and a Model 900766 Bellow Style Vacuum Cup, with a 0.73″ diameter face…our smallest, and ideally sized for a golf ball.  They, however, have a VERY limited supply of compressed air, so the difference between the Model 810002M’s compressed air consumption (2.3 SCFM @80psig) and the Model 800001M E-Vac High Vacuum (Non-Porous Duty) Generator w/Muffler (1.5 SCFM @80psig) was worth considering.  Also, we figured that they might be able to use a Model 900804 Check Valve, so the only time they’d need to supply air was to pick it up, and, possibly intermittently to maintain the vacuum.  So, golf ball in hand, off to the Efficiency Lab I went.  I also took our trusty video camera:

As you can see, it locked on to the golf ball instantly, and the Check Valve allowed the Vacuum Cup to hold the ball for over 13 seconds with no air flow to the E-Vac, proving that there isn’t much leakage at all past those dimples.  I suspect we’ll be seeing this robotics class team in the winner’s circle at the competition.

In most cases, the difference between 1.5 SCFM and 2.3 SCFM consumption may go unnoticed when picking a short-duration pick-and place vacuum generator.  The higher usage product’s supply pressure can always be regulated down to reduce compressed air consumption and use only what’s necessary to do the task…we, in fact, recommend that on ANY compressed air application.  In this case, though, it was worth finding out.

If you have a pick-and-place application that you’d like help with in selecting the right system, give me a call.

Russ Bowman
Application Engineer
(513)671-3322 local
(800)923-9247 toll free
Visit us on the Web
Follow me on Twitter
Like us on Facebook