Building an E-Vac Vacuum Generator System

EXAIR’s In-Line and Adjustable E-Vacs are a powerful compressed air powered vacuum generator. They’re a low-cost way to create a vacuum for a variety of different applications: pick and place, clamping, chucking, lifting, surface mounting, and vacuum forming are just some of the possibilities. Both the In-Line and Adjustable E-Vacs are available in a variety of different sizes and flows and can accommodate a wide range of applications.

With no moving parts to wear out, EXAIR’s E-Vacs are virtually maintenance free when supplied with clean, dry compressed air. In-Line E-Vacs are available in two different styles: High Volume, Low Vacuum for use with porous materials and Low Volume, High Vacuum for use with non-porous materials.

For pick and place or lifting applications, vacuum cups will be necessary. With a wide variety of different vacuum cups available: Small Round, Large Round, Oval, and Bellows, we can accommodate nearly any size or shape material. For heavier materials, round cups with cleats provide rigidity and ensure that the load remains stable. For applications on textured or uneven surfaces, Bellows style cups have convolutions that allow for the cup to quickly decompress when it touches the surface of an uneven part or material. To determine the most suitable cup, we must consider the weight of the material and the orientation it will be lifted.

Vacuum cups

If it is being lifted with the vacuum cups positioned horizontally, use a safety factor of 2. For applications where the part or material will be lifted vertically, use a safety factor of 4. This safety factor is then multiplied by the weight of the material. You’ll then need to determine how many vacuum cups are needed. No more than 4 vacuum cups should be used with any one E-Vac. Consider the size/shape of the material to be lifted and place vacuum cups accordingly to evenly distribute the weight. Heavier and larger materials may necessitate the use of more than one E-Vac.

The weight a particular cup can hold at a given pressure is shown in the chart below. Once you’ve determined a suitable cup based on the weight and orientation of the lift, a variety of other accessories are also available.

vacuum cup weights

The vacuum port of the E-Vac has an NPT thread, vacuum cups can be installed directly in this inlet. For applications where the vacuum cup(s) are remotely located, we offer polyurethane vacuum tubing as well as a variety of different fittings to connect them. Both 1/4” and 3/8” O.D. sizes are available in 10’ lengths up to 50’. Simply indicate the model number of the tubing and add the length with a “-“ at the suffix. In addition to fittings and tubing, vacuum check valves are also available. These can be beneficial if there is potential for fluctuations in the compressed air pressure or supply. In the event that there is a significant drop in pressure or loss of compressed air supply, the check valve will ensure that the load remains stable.

To minimize the sound level and ensure you’re adhering to OSHA 1910.95, we have Standard Mufflers as well as Straight Through Mufflers. The Straight Through Mufflers offer the best level of sound reduction, up to 26 dBA!!

E-Vac Mufflers

With all of the different options making a selection can seem like a daunting task. If you’re struggling to determine the most suitable E-Vac and Accessories for your application, give an Application Engineer a call today!

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@Exair.com
Twitter: @EXAIR_TD

I Pick Things Up & I Put Them Down

This past weekend in Columbus, OH was a sporting event hosted by Arnold Schwarzenegger.  This event has many aspects of it and this past weekend was the first year where spectators were not permitted due to the COVID-19 risks and scares.  The caterer for the event had already prepped all of the food to prepare for thousands of people so instead of donating locally, they connected with head chefs in Nashville, TN to create a “tailgate extravaganza” to try and lift the community up after the recent tornado and storms ravaged the area and demolished homes as well as communities.  The Arnold still happened, with participants only, they were all, “Picking Things Up and Putting Them Down.”

Arnold Sport’s World Record Lift

Seeing these giant athletes perform deadlifts always reminds me of the EXAIR Adjustable E-Vacs and how they are used frequently to pick things up and put them down.  When determining the correct Adjustable E-Vac I always like to start with the shape, weight, and surface of the part.  This is how I determine which vacuum cup can be utilized.  The good news is as a customer, the choice doesn’t have to be made alone, that is why the Application Engineering team is here, we’ll help you determine which vacuum cup will suit the given application.

These are all examples of how an E-Vac pick-and-place system is just a solenoid valve away from automation.

Some of the factors we use to determine the suction cup is listed out below.

Is the lift going to be a vertical cup lift or a horizontal cup lift?  This means is the face of the cup vertical, picking up a box from the ground by the sides, or is it going to be horizontal where the face of the cup sits horizontally over the part.

For a vertical cup face, if lifting the part up vertically then a bellows cup will not be suitable and something with a cleat will be needed due to the rigidity of the cup to help keep the cup and part stable.  The bellows may collapse due to the weight of the product, where the cleats will interface with the part and create a solid connection to aid in the lift.

For a horizontal cup face, if lifting the part up vertically then a bellows cup would work ideal in the event the surface is uneven.  Maybe one end is slightly taller, in this scenario, a bellows cup would help the cups to all seal to the surface and still be able to pick up the item.  These cups are also thinner to help adapt to an irregular surface on the part or to help keep suction if the part deforms upon being picked up. The bellows is not recommended for rather heavy objects as the bellows may collapse under extensive load and cause the cup to lose suction.

Talking about the weight of the item, this also becomes a major factor as each cup has a maximum lifting weight and that is determined by the surface area of the cup as well as whether it has cleats, bellows, or just a plain cup.  Our goal when sizing the cups to the parts is to ensure they are going to engage the surface in a solid secure manner that makes the lifting rig safe and stable to use.

For example, take a look at this solar lens manufacturer who utilizes many EXAIR products in this pick and place operation.

If you would like to discuss your Adjustable E-Vac, Vacuum Cup, or heavy lifting, please contact me.

Brian Farno
Application Engineer
@EXAIR_BF
BrianFarno@EXAIR.com

 

The 2020 ASF Media Room – Arnold Sports Festival, 2020 – https://www.arnoldsportsfestival.com/visitor-info/media/

 

What is the Venturi Effect?

In 1797 a Italian physicist named Giovanni Battista Venturi wrote a dissertation on the “Venturi Effect”.  However, an actual device was never created or applied until 1888 where Clemens Herschel was awarded the patent for the first Venturi tube.

The Venturi effect is a decrease in fluid pressure when fluid flows through a constricted area of a pipe.  In other words, as the diameter becomes smaller, the fluid velocity becomes faster.  This increase in velocity will create a lower pressure just past the constricted area.  When designed correctly, you can create a strong vacuum or a large negative pressure.

The EXAIR E-Vac® Vacuum Generators use this phenomenon by using compressed air as the fluid.  This type of Venturi tube restricts the internal area to generate a fast velocity through the body creating a vacuum pressure for suction.

EXAIR offers three types of Venturi tubes; low vacuum, high vacuum and adjustable.  Low vacuum units are typically used with porous material because the trade off for low vacuum is higher vacuum flow. The high vacuum generators can create a vacuum level as high as 27” Hg (71 KPa).  The Adjustable E-Vacs can alter the internal air velocities by turning the body and getting different vacuum pressures.  Without any moving parts or electric motors to break, the EXAIR E-Vacs are a simple design that is very durable, effective and long-lasting.  A great product for applications like pick and place, clamping, lifting and vacuum forming.

In-Line E-Vac How It Works
EXAIR E-Vacs provide instantaneous vacuum response, and are engineered for high efficiency to minimize air consumption.

The Venturi effect was discovered in 1797, brought into existence in 1888, and is still used in vacuum applications to this very day.  If you have an application where a Venturi tube could help you, please contact an Application Engineer.  We will be happy to assist you.

Jordan Shouse
Application Engineer
Find us on the Web http://www.exair.com/28/home.htm
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Porous and Non-Porous E-Vac Vacuum Generators

Getting a vacuum from compressed air seems a bit like magic, but it works and it works well. EXAIR’s E-Vac® Vacuum Generators are compressed air powered, single stage vacuum generators. They are a low cost way to create vacuum for pick and place, clamping, lifting, chucking, vacuum forming and other applications.

The Low Vacuum Generators are ideal for ‘porous’ types of applications.  When we say ‘porous’ we are describing those processes where a lighter vacuum level combined with higher vacuum flows are needed. A good example of this is lifting a cardboard box. The cardboard is not air tight, and when you place a vacuum on it, air is able to be pulled through the cardboard. To maintain the vacuum level, the air needs to be able to be pulled through the cardboard and exhausted as fast as it is being pulled through in order to maintain the vacuum level. This requires higher vacuum flow and the design of the Low Vacuum Generator allows for the development of a good vacuum level and a high rate of vacuum flow.

The High Vacuum Generator is ideal for ‘non-porous’ type of applications. ‘Non-porous’ are those processes where the material is air tight, and no or very little air can pass through. Material such as glass, ceramic, and steel are ‘non-porous’. Because little or no air passes through, the need for high vacuum flow is not as important, and the highest of vacuum level can be achieved. A perfect vacuum is 29.92 in-Hg, and the High Vacuum Generator is designed to reach vacuum levels of 27 in-Hg, or a 90% vacuum level.

 

E-Vac Video

 

Click above Image to View the Video

Both the Low Vacuum and High Vacuum Generators come in 7 different sizes, ranging from light to very strong vacuum capabilities, to match any application. Special Kits are  available as a way to experiment with an assortment of vacuum cups to determine the best configuration.

evac_nonporouskit
E-Vac Kit

And for maximum flexibility, EXAIR offers the Adjustable E-Vac Vacuum Generator. Engineered for high efficiency, compressed air can be minimized due to the ability to adjust and tune the vacuum flow and level to perfectly match the application requirements.

adjevac
Lifting a Concrete Block with the Adjustable E-Vac Vacuum Generator

If you have questions about vacuum generation and the E-Vac or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

 

Brian Bergmann
Application Engineer
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Twitter: @EXAIR_BB

Vacuum Generator Accessories

In my last blog, I went over How to Choose/Build an E-Vac system, and you can read about that here–  The E-Vac’s are a compressed air powered, single stage vacuum generator, providing a low cost solution for creating a vacuum for many applications. Today, we will look at the many accessories that are available to complete a vacuum system best suited to your vacuum application.

For pick and place operations and hold down or clamping processes, we offer an array of Vacuum Cups. Available from stock are small and large Round, Oval, and Bellows styles. Round cups are best suited for smooth, flat surfaces.  Oval cups provide the most vacuum due to the larger surface area, making them ideal for lifting heavy loads. The Bellows style is best suited for textured or uneven surfaces, where the folds provide a collapsible area that allows the cup to compress and seal to the uneven surface.

vacupfam
Small and Large Round, Oval and Bellows Vacuum Cups

For vacuum processes where personnel are nearby, there are two (2) types of mufflers available to reduce the sound level to comply with the limits OSHA Standard 29 CFR – 1910.95(a) has established. The EXAIR E-Vac Mufflers are designed so that the E-Vac exhaust is not impeded, so that the highest and fastest vacuum response is achieved. The Standard Muffler (for use with In-Line E-Vacs only) has a closed end and is best suited for vacuum draws that are free from dust and debris.  The Straight Through Muffler is open all the way through and is recommended for those vacuum draws where there will be dirt and debris, since it will not plug up. The Straight Through style offers the best sound level reduction, up to 26 dBA.

E-Vac Mufflers
Standard and Straight Through Mufflers

The vacuum port of the E-Vacs has an NPT threaded connection and with a suitable connector, a vacuum cup can be closely installed, minimizing the system air volume. When vacuum cups are to be remotely mounted, Push-In Connector Type Fittings of assorted styles are available along with the polyurethane tubing to make the installation and vacuum plumbing a cinch.

E-Vac Fittings
Push-In , Swivel Elbow, Swivel Branch Tee, and Bulkhead Connectors

And finally, to get the best performance and maintenance free operation from your E-Vac, always use a source of clean, dry compressed air. We can help you do that with a wide array of Automatic Drain Filter Separators and Oil Removal Filters sized to pair up with the various E-Vac’s. Also available are Pressure Regulators, Vacuum Gauges, Manual Shut Off Valves, Solenoid Valves, and Compressed Air Hose.

If you have questions about E-Vacs and accessories or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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Twitter: @EXAIR_BB

How to Choose A Vacuum Generator for Your Application

EXAIR’s compressed air powered E-Vac single stage vacuum generators are a low cost way create vacuum for many operations including- pick and place, clamping, chucking, alignment, lifting, and many others.

The E-Vac provide instantaneous response and are commonly used for pick and place operations.

EXAIR offers the In-Line and Adjustable style of E-Vacs. Both are compact and easy to mount at point of use. With 18 total models available, there is sure to be one that meets any application.

Industrial Robot
An E-Vac in Robotic Lift Operation

How to Build An E-Vac System:

Step 1 – Select E-Vac type:

A – Determine if the part to be lifted is porous (Example, cardboard) or non-porous (Example, plastic sheet)

  • Porous materials require a low vacuum generator which produces a lower vacuum in exchange for higher vacuum flow which is capable of maintaining a good vacuum level through material that aloows air to flow through itself.
  • Non-Porous materials are best suited to use the high vacuum generator which is capable of producing more powerful vacuum for the application.

B – Select a style of E-Vac – In-Line Low Vacuum, In-Line High Vacuum, or Adjustable

  • Porous – low vacuum generator, max vacuum = 21″ Hg (71 kPa)
  • Non-Porous – high vacuum generator, max vacuum = 27″ Hg (91 kPa)
  • Adjustable – max vacuum = 25″ Hg (85 kPa)

Step 2 – Find the weight of the part to be lifted:

Step 3 – Multiply the weight by a vacuum cup safety factor (2 for a horizontal vacuum cup position, and 4 for a sideways vacuum cup position)

Step 4 – Determine the number of cups needed, considering the following:

A – How many cups are needed to evenly distribute the weight for stable lifting and placement.

B – What is the weight that each vacuum cup can lift based on maximum vacuum available?

C – Select the appropriate vacuum cup from the different styles available.

Step 5 – Choose the E-Vac model, considering the entire vacuum system from the E-vac to the part:

A – Number of vacuum cups per E-Vac.

B – Length and size of the vacuum tubing.

C – Vacuum cup size and type.

  • The volume of air to evacuate from your vacuum system and the vacuum flow of the E-Vac selected will determine the time it takes to build the lifting vacuum level.
  • A lower volume of air in the system and/or higher capacity (SCFM/SLPM) E-Vac will result in faster pick-up times.
  • It is difficult to calculate an exact pick-up time.

Example – Sheet of material 3′ x 3′ (0.91m x 0.91 m) that weighs 25 lbs. (11.3 kg). Each sheet is in stack and will be placed on a conveyor.E-Vac Example

As you can see, there is a lot to consider when building an E-Vac system. Feel free to contact us and we can help go through the steps.

If you have questions about E-Vacs or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
Send me an email
Find us on the Web 
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Twitter: @EXAIR_BB

Overview: Adjustable E-Vac Vacuum Generators and Vacuum Cups

Adjustable E-Vac

When it comes to vacuum systems, EXAIR manufactures a very compact and reliable product line called the E-Vac Vacuum Generators.  As a simple vacuum pump, you only need to connect to a compressed air source.  It uses a venturi design to generate high vacuum levels very efficiently.  Since they do not require motors, they are low cost with a wide range of vacuum flows and pressures.  EXAIR offers three different types, the High Vacuum Generators for non-porous objects, the Low Vacuum Generators for porous objects, and the Adjustable E-Vac Vacuum Generators.  In this blog, I will cover the Adjustable E-Vac Vacuum Generators and the variety of suction cups that we provide.

The Adjustable E-Vac gives flexibility to your vacuum system to change the vacuum levels.  The simplicity in the design makes it a great tool for lifting, clamping, chucking, and pick-and-place.  The design also allows for adjustability.  By loosening a lock nut, you can turn the body to reach different vacuum levels.  So, they can be used to move both porous and non-porous materials.  We offer four different sizes with vacuum flows ranging from 5.8 SCFM (164.2 SLPM) to 81 SCFM (2293.6 SLPM).  With the Adjustable E-Vac, you can change the vacuum pressure to go as high as 25” Hg (85 KPa).  Ideal for dialing in the correct vacuum for delicate materials or controlled clamping.

Adjustable E-Vac: How it works

The Adjustable E-Vacs can be packaged in a variety of ways.  The kits help to experiment with different vacuum cups to help determine the best fit for your application.  EXAIR offers two types of kits, the standard kit and the deluxe kit.  The Adjustable E-Vac Kit would include the E-Vac, an assortment of four vacuum cups that are matched to the performance of the Adjustable E-Vac, an assortment of vacuum fittings and 10 feet (3 meters) of vacuum tubing.  The Adjustable E-Vac Deluxe Kit has the items in the standard kit above plus an Automatic Drain Filter and Pressure Regulator with gage.  With both individual units and kits, you can add a muffler to help reduce the noise even more by adding an “M” to the end of the model number.

EXAIR also offers a variety of suction cups to attach to a variety of objects.  We have the small round, the large round, the oval, and the bellows suction cups.  With the different designs, you can pick up a wide range of materials, both porous and non-porous items.  The vinyl material resists wear and distortion for many repetitive cycles.  Here is a better description of each cup below:

Round Cups

Round:  EXAIR has a small and large round style.  This gives us a range of surface areas that we can target to help maximize lift.  They can come either with cleats for heavier lifting and stability or without cleats.  They work great with flat smooth surfaces for horizontal and vertical lifting.

Oval Cup

Oval:  The vacuum is defined by a skinny long area.  EXAIR offers four different sizes.  If you have tight spaces or selectable targets like opening a bag at the top, then the oval shape will work.  They can also handle flat rigid sheets like wood, glass, cardboard, and composites.

Bellows Cup

Bellows:  These suction cups are best suited for uneven or contoured surfaces.  The convolutions around the diameter allow for the cup to collapse and “wrap” around uneven surfaces.  The internal volume is larger than the other cups, so the release and attach times will be extended.  But, for odd surface formations, they can come in very handy.

To combine the Adjustable E-Vac with the Vacuum Cups, how can we determine which ones to use in your application?  Here is some information that we will have to know before getting started.  I like to use anagrams for memory recall, and here is a list that I like to call MOST:

  1. Material
  2. Orientation
  3. Size/weight
  4. Time

Material will tell us if the object is porous or non-porous.  Porous objects are items like cardboard, fabric, cement, etc.  The material can have a rough surface or pores that will allow air to pass through or around the cup.  The Adjustable E-Vac can have the vacuum pressure altered to pick up the material without damaging the surface.   Non-porous objects are items like glass, metal sheets, and plastic.  They have a smooth texture on the surface.  These materials should use the highest vacuum pressure of 25” Hg (85 KPa) to hold the most weight.

Orientation will help us to calculate a safety factor.  EXAIR’s motto has always been safety.  This is important because we want to make sure that the object is secure during movement.  We just need to know if the object is being picked up horizontally only, or if the object is being picked up vertically or rotated in a vertical position.  Then we can apply a safety factor to handle the weight in any orientation.

Size/Weight is simple.  The size is the area that we can pick up the object.  In some instances, we may only have a small target area while in other applications, we will have an entire sheet.  The type of Vacuum Cups is selected by this target area.  The weight will determine the number of Vacuum Cups and Adjustable E-Vacs required to pick up large objects safely.

Time is for applications with cycle rates.  If the job requires a set time to support and release in a known time frame, then we can determine the correct Adjustable E-Vac This can be used for leak checking, clamping, and automatic packaging.

The Adjustable E-Vac Generators are simple, flexible, and very reliable.  As a vacuum pump, they are very compact because they do not use any motors which can wear out.  If you contact an Application Engineer at EXAIR with MOST, we will be able to get the most from your vacuum system.

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