Benefits of Working with EXAIR

30 Day Guarantee

Consider EXAIR as the source of your problem solving products for the following reasons. Our Application Engineers are waiting for your call, e-mail or live chat. They have over 70 years manufacturing experience between them and have experience with an impressive number of different industries and process problems. Add our customer service staff to that mix and you will experience orders that are shipped the same or next day (orders received by 2pm EXAIR time ship same day), with a fast and accurate order confirmation. EXAIR shipped products on-time 99.8% in 2021, and we continue that into 2022.

Our website and catalog include 16 problem solving product lines and thousands of products, technical data, photos and drawings to help you with your project. When reviewing our website or catalog, chances are you will find the answers to some of your industrial/production problems. Our catalog products are stock items, so in most cases we will process and ship orders the same day! Having the capability to get our products to your facility allows you to begin familiarizing yourself with our product(s) and perform trial(s). Since we manufacture these products locally, in Cincinnati, OH, we have the ability to make custom solutions if any of our stock products do not meet your needs.

EXAIR has competitive prices but you will also see cost savings from the efficiencies you realize with our Intelligent Compressed Air Products. Reducing your SCFM usage will decrease your energy cost. Our products also come with EXAIR’s 5 year Built to Last Warranty!

EXAIR leads the way in standards compliance by making certain our products meet the standards set forth by many organizations. You will see CE, RoHS, REACH, Conflict Mineral Free and OSHA compliance are common for our products. When considering safety, our products meet or exceed OSHA Standards 29 CFR-1910.95 (a) maximum allowable noise exposure and OSHA standard CFR 1910.22 (b) harmful dead end pressure.

Please visit www.EXAIR.com or request a catalog.

Eric Kuhnash
Application Engineer
E-mail: EricKuhnash@EXAIR.com
Twitter: @EXAIR_EK

The Venturi Effect: Discovered by Giovanni Battista Venturi

Giovanni Battista Venturi was born in 1746 to an affluent family in Reggio, Italy. An aspiring student, Giovanni was ordained as a priest and a professor by the age of 23. An avid historian of science at the University of Modena, he was the first to emphasize Leonardo da Vinci as a scientist rather than just an artist as he’s more commonly known. Despite his love for history, it wasn’t long before the University of Modena became aware of his talents in mathematics where they appointed him as professor of geometry and philosophy in 1774. During his tenure at the University of Modena, Giovanni was promoted to the Professor of Experimental Physics, served as the Duke of Modena as the State engineer and auditor, later serving diplomatic roles in both France and Switzerland.

Giovanni is most well-known for his work in developing what is now known as the venturi effect. In 1797, he published a study on the flow of water through short cylindrical tubes. It wasn’t until 1888 that Venturi’s design was applied to something practical when a man named Clemens Herschel received a patent for the first commercial venturi tube. The original purpose of the venturi tube was to measure the amount of water used in individual water mills and is still used to this day as a means of measuring fluid flows.

Venturi tube.jpg
Venturi Tube

The venturi effect is a principle in fluid dynamics and states that a fluid’s velocity must increase as it passes through a constricted pipe. As this occurs, the velocity increases while the static pressure decreases. The pressure drop that accompanies the increase in velocity is fundamental to the laws of physics. This is known as Bernoulli’s principle. Below is an illustration of how the venturi effect works inside of a constricted tube.

venturi

In everyday life, the venturi principle can be found inside of many small engines such as lawn mowers, gas powered scooters, motorcycles and older style automobiles. Inside the carburetor, there is a small tube through which filtered air flows from the intake. Inside of this tube is a short narrowing. When the air is forced to constrict, its velocity increases and creates a vacuum. This vacuum draws in fuel and mixes with the air stream causing it to atomize.  As the throttle valve is opened further, more fuel is forced into the engine. This increases the RPM and creates more power.

inlineworks
In-Line E-Vac

This principle is also applied to EXAIR’s line of E-Vac products to create vacuum. The .gif below illustrates how an In-Line E-vac works. (1) Compressed air flows through the inlet (2) and is directed through a nozzle, constricting the flow of air. (3) As the air stream exhausts, it expands causing a decrease in pressure and an increase in velocity prior to passing through the venturi. (4) A vacuum inlet tangential to the primary airflow is located at the suction point between the orifice and the venturi. (5) The airflow that is drawn through the vacuum inlet mixes with the primary airstream, then exhausts on the opposite end.

The venturi effect is used in a variety of other EXAIR products used for cooling, drying and cleaning, in addition to the vacuum generators. If you have a process in your facility that may benefit from an Intelligent Compressed Air solution, give us a call. We’d be happy to discuss your application and implement a solution to both reduce your compressed air costs and improve worker safety.

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

Photo: Venturi Tube with labels by ComputerGeezer and Geof.  GNU Free Documentation License

How To Choose The Right Style & Size Vacuum Cup

When you are using vacuum to pick and place different objects, how do you know which style vacuum cup and size you need?  EXAIR offer’s (3) different styles of vacuum cups in a variety of sizes to cover a wide variety of applications.

The first is the round cup, they are suited to smooth, flat surfaces.  They grip and release quickly, hold their shape with frequent use, and grip well when used with vertical loads.  Also, round cups are offered with cleats for a better gripping power when the load is heavy.  Vacuum Cups with cleats provide extra rigidity that lends itself to heavy loads.  The extra rigidity prevents the cup from peeling away or deforming when a heavy load is required.

Large Round Cleated Vacuum Cup
Round Cup With Cleats

Next we have the Oval Cup, they provide the most gripping power due to their larger surface area.  They naturally lend themselves to heavier loads.  They are ideal for flat rigid sheet materials such as wood, glass, cardboard and composites.

Oval cup
Oval Cups Provide The Most Vacuum Which Make Them Ideal For Heavy Loads Due To Their Larger Contact Area

Last but not least we have the Bellows Cup, they are best suited for curved, uneven or textured surfaces.  The bellows or more accurately called “convolutions”, provide a collapsible area that allows the cup to quickly compress when it contacts the surface of item to be moved.  Please know that the grip/release time is greater due the the larger internal volume of the cup.

bellows cup
Bellows Cup Are Excellent For Uneven Or Textured Surfaces, However They Longer Pick-Up & Release Times

Here is an example: If we want to pick up a sheet of glass that weighs 20 lbs, what size vacuum cup(s) do we need?  Fortunately we have published charts in our catalog with the math already completed, but this is how we arrived at the answer.  Using the formula below:

Cup Diameter Formula

D = Cup Diameter
W = Weight of item
N = Factor of safety ( We recommend a safety factor of 2 for horizontal lifting and 4 for vertical lifting).  For this exercise we will use a safety factor of 4.
U = # of cups (Remember it takes a minimum of 3 points to make a plane)
V = Vacuum level (psi) – Exair Porous E-Vac’s are rated to 21″ HG, Non – Porous 27″ HG and the Adjustable E-Vac 25″ HG.   (Each inch of HG equals .491154 PSI)
π = 3.14159
μ = Vertical surface friction coefficient (.5 for typical non-porous materials such as metal, glass, stone, etc..)

Cup Diameter Formula Solved

The calculated diameter is 2.26″ so we would choose the next standard size which is 2.5″ diameter.

When you are looking for Vacuum Cup application assistance or expert advice on safe, quiet and efficient point of use compressed air products give us a call.   We would enjoy hearing from you!

Russ Bowman, CCASS

Application Engineer
EXAIR Corporation
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Carburetors and Venturi Tubes: Thank You Giovanni Battista Venturi

I know it has been a little while since I blogged about something with a motor so it should be no surprise that this one ties to something with a combustion chamber. This all starts with an Italian physicist, Giovanni Battista Venturi. His career was as a historian of science and a professor at the University of Modena. He gave Leonardo da Vinci’s creations a different perspective by crediting da Vinci to be a scientist with many of his creations rather than just an amazing artist. He then began to study fluid flow through tubes. This study became known as the Venturi Tube. The first patents in 1888 came to fruition long after Giovanni passed away. So what was this Venturi effect and how does it tie in to carburetors let alone compressed air?

The illustration below showcases the Venturi effect of a fluid within a pipe that has a constriction. The principle states that a fluid’s velocity must increase as it passes through a constricted pipe. As this occurs, the velocity increases while the static pressure decreases. The pressure drop that accompanies the increase in velocity is fundamental to the laws of physics. This is another principle we like to discuss known as Bernoulli’s principle.

1 – Venturi

Some of the first patents using Venturi’s began to appear in 1888. One of the key inventors for this was Karl Benz who founded Mercedes. This is how the Venturi principle ties into combustion engines for those that do not know the history. This patent is one of many that came out referencing the Venturi principle and carburetors. The carburetors can vary considerably in the complexity of their design. Many of the units all have a pipe that narrows in the center and expands back out, thus causing the pressure to fall and the velocity to increase. Yes, I just described a Venturi, this effect is what causes the fuel to be drawn into the carburetor. The higher velocity on the input (due to this narrowing restriction) results in higher volumes of fuel which results in higher engine rpms. The image below showcases Benz’s first patent using the Venturi.

2 – Venturi Patent

While carburetors slowly disappear and now can mainly be found in small engines such as weed eaters, lawn mowers, and leaf blowers, the Venturi principle continues to be found in industry and other items. Needless to say, I think Giovanni Battista Venturi would be proud of his findings and understanding how monumental they have been for technological advancements. For this, we will recognize the upcoming day of his passing 199 years ago on April 24, 1822.

Brian Farno
Application Engineer
BrianFarno@exair.com
@EXAIR_BF

1 – Thierry Dugnolle, CC0, Venturi.gif, retrieved via Wikimedia Commons https://upload.wikimedia.org/wikipedia/commons/1/16/Venturi.gif

2 – United States Patent and Trademark Office – Benz, Karl, Carburetor – Retrieved from https://pdfpiw.uspto.gov/.piw?Docid=00382585&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO1%2526Sect2%3DHITOFF%2526d%3DPALL%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsrchnum.htm%2526r%3D1%2526f%3DG%2526l%3D50%2526s1%3D0382,585.PN.%2526OS%3DPN%2F0382,585%2526RS%3DPN%2F0382,585&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page