A Simple Explanation of the Venturi Effect

The Venturi Effect was discovered by Italian physicist Giovanni Battista Venturi who lived between 1746 and 1822. In practice, there were a number of other physicists who were involved in the Venturi Effect but Giovanni Venturi is generally accepted as the first person to discover and explain the effect. So, what is the Venturi Effect, and how does it affect practical everyday living?

“A Venturi is a system for speeding the flow of the fluid by constricting it in a cone shape tube. In the restriction, the fluid increases its velocity, which reduces its pressure and produces a partial vacuum. As the fluid leaves the constriction, its pressure increases back to the ambient or pipe level.”

Any substance that flows is considered a fluid. This includes such things as water, shampoo, sunscreen, and even honey. Although not necessarily obvious, even gases, such as air, can be classified as fluids. So why would someone at EXAIR be talking about Venturi? Our E-Vacs use the Venturi Effect to create vacuum

This image has an empty alt attribute; its file name is in-line-e-vac-how-it-works.jpg

For most people the Venturi Effect is difficult to understand because you might expect the pressure to increase when a fluid is pushed through a restricted area. The fact that the increase in velocity is greater than any potential increase in pressure means that there is a net increase in velocity and a net reduction in pressure. The ability to mix-and-match certain fluids and gases via this process is relatively straightforward because the reduced pressure allows other substances to be sucked in through a connecting pipe at a rate of your choice.

EXAIR uses the Venturi Effect and other principles within the development of our engineered products. If you have questions or need a solution please call 800.903.9247 or visit us on www.EXAIR.com and let us help you.

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


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

E-Vac For Lubricant Recovery

Over the last 3 months, I have been in contact with a customer, keeping track of an application that involved the EXAIR E-Vac.  The customer had reached out to us looking for some advice on how to solve a process problem. The operation is a drawing/stamping process, and the when the part exits the machine there is coolant that resides in a deep draw section, approx 0.4″ in diameter by 3.5″deep.  About 1 oz of coolant per part is retained, and over many 1000’s of parts, would add up to lost dollars and messy clean up.

The customer was looking for an automated process that would be able to draw out the coolant and direct the liquid back to the coolant reservoir, all while maintaining the current machine run rate. We settled in on the model 840015 Adjustable E-Vac Generator. The Adjustable E-Vac has a straight through pathway from suction through to discharge, allowing for fast evacuation times.  A simple turn of the unit changes the vacuum and flow levels to best match the needs of the application.  The Adjustable E-Vac coupled to a solenoid valve controlled by the stamping machine resulted in the automatic system the customer was looking for.

Adjustable EVac
Adjustable E-Vac Family

The customer ordered a unit, and based on the preliminary bench testing, it was approved for a production run trial. After some tweaking in the production environment, the unit was performing to spec, and was then subjected to a 100,000+ part run.  The results were a success!  Instead of the parts exiting onto an inclined conveyor, relying on gravity to drain and causing coolant to collect under the conveyor, the coolant could be removed in a controlled manner and sent back to the reservoir.  Less mess and no coolant loss.

EXAIR manufactures (3) types of E-Vacs – Low vacuum generators for porous materials, high vacuum generators for non-porous materials, and the adjustable type for flexible vacuum performance.  They are available in multiple sizes, to best match the vacuum requirements, while using the least amount of compressed air.

To discuss your application and how the EXAIR E-VAC can benefit your process, feel free to contact EXAIR and myself or one of our other Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer

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Twitter: @EXAIR_BB

Custom, Flanged Air Amplifier Solves a Fume Evacuation Problem

We blog about this topic quite a bit, and almost every section of our catalog has a page set aside just for special / custom product configurations that have been created by request from many of our customers.

This is the latest and greatest special that I have seen roll through the production area here at EXAIR.   This is a special 4″ 303 Stainless Steel Adjustable Air Amplifier with a 4″ Tri-Clamp flange on the discharge side and a 6″ Tri-Clamp flange on the suction side of the amplifier.


This had been an ongoing project with the customer that started with them testing a stock Adjustable Air Amplifier in the application to ensure that the performance would meet their needs.  The application was to boost a low flowing fume exhaust that was causing slow downs in their production line.  Fans and other traditional methods would require maintenance and would wear out.  The stock Adj. Air Amplifiers exceeded their performance needs but did not easily mount into their duct work because they used all standard size tri-clamp fitting in the ducting, so the next step was to see if we could manufacture a Special Adjustable Air Amplifier just for their needs.  The dimensions of the existing Adjustable Air Amplifier came close enough we were able to easily create a Flanged Adjsutable Air Amplifier that would clamp straight into their existing duct work, exceed their performance expectations, help their process, and be ready to ship within a very reasonable lead time.

Like we have said before, if a stock, cataloged, product doesn’t fit your application exactly, contact us and let us find a way to customize and fit the need.

Brian Farno
Application Engineer Manager