Giovanni Battista Venturi: A Real Renaissance Man

Leonardo Da Vinci (1452-1519) was the quintessential Renaissance Man: artist, philosopher, scientist, mathematician, and an inventor ahead of his time. From the 15th to 18th Centuries, though, he was primarily known for his paintings. Then, in 1797, Giovanni Battista Venturi published his “Essai sur les ouvrages physico-mathématiques de Léonard de Vinci”, which brought to light Da Vinci’s immense volume of work in the scientific fields of fluid dynamics and aerodynamics. Curiously, he was only able to do this because of the access he gained to notebooks that had been looted by Napoleon’s troops during their occupation of Milan, Italy, and brought back to France.

To conclude that Venturi was just a writer, though, would be as bad as regrettable as calling Da Vinci just a painter. Born into a rich family in northern Italy, he was a star pupil at the Jesuit seminary in his hometown of Bibbiano. He was such a good student that in 1756 – at the age of ten – he started attending the seminary in Reggio Emilia, studying logic, metaphysics, and mathematics.

As a teenager, he enrolled in the university there, studying physics and biology before returning to the seminary, where he was ordained as a priest in 1769. He taught logic at the seminary for five years, and then went on to “the big city” of Modena to teach philosophy and geometry at the university there. He was 28 when he started there, and by age 30 he was teaching physics as well.

In addition to his service in the priesthood and at the university, he also held the office of official state engineer, mathematician, and auditor, appointed by the Duke of Modena. This meant he was responsible for the construction of bridges, draining of marsh land, and implementing regulations for the building of dams. And, in his spare time, it seems he also completed the town of Modena’s historical memoirs, a task that had been started by the town historian, but had remained dormant since his passing, some 56 years earlier.

All of this would have earned Venturi local, probably regional, and perhaps even national fame…especially the part about making Leonardo Da Vinci famous for more than just his art. But what really sealed his place in the annals of history was his discovery of a particular fluidic effect: namely, that a reduction in fluid pressure results when a fluid flows from one section of a pipe into a narrower section.

The Venturi effect, named after the real Renaissance man who discovered it, Giovanni Battista Venturi who published a paper on it in 1794.

Despite its discovery in the late 18th Century, it was not actually practically applied for almost 100 years, when an American hydraulic engineer named Clemens Herschel patented a water flow meter, in 1889. He named it the Venturi Meter, and they became prolific in water works around the turn of the century. Coincidentally, Mr. Herschel had a background in bridge building too.

Today, there are numerous machines that use the Venturi effect: fluid moving educator pumps, gas inspirators in grills, stoves, & Bunsen burners, paint atomizers, wine aerators, locomotive engine steam injectors, sandblasting nozzles, scuba diving regulators…and vacuum generators.

That last one is where EXAIR gets involved. We incorporate Venturis into our E-Vac Vacuum Generators, which are capable of vacuum levels up to 27″Hg. They’re used for material handling, pick & place systems, bag/package opening, label placement, vacuum forming, and workholding, just to name a few.

The wide throat diameter of the Adjustable E-Vac makes it suitable for applications where small amounts of particulate and/or liquid may be drawn through.

They’re also used in our Reversible Drum Vac and EasySwitch Wet-Dry Vac Systems. These are just two selections from our extensive line of compressed air operated Industrial Housekeeping Products.

EXAIR Reversible Drum Vacs (left) can fill a 55 gallon drum with water in 90 seconds, using a powerful Venturi. Our Chip Trapper Systems (middle) incorporate a Reversible Drum Vac to vacuum coolant from machine tool sumps for filtration. The EasySwitch Wet-Dry Vac uses a Venturi as well for dry and liquid cleanup applications.

Giovanni Battista Venturi retired in 1813, but continued writing a number of scientific and literary works, including a collection of Galileo’s manuscripts & letters. He died in 1822, at the age of 75.

Russ Bowman, CCASS

Application Engineer
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My Take on EXAIR’s Adjustable E-Vacs: Wear-Free Vacuum Technology

When it comes to innovative solutions for industrial applications using compressed air, EXAIR has long been a trusted name, and our Evac vacuum generators are no exception. These compressed air-powered devices are designed to create a powerful vacuum with remarkable efficiency, making them ideal for a wide range of tasks—from pick-and-place operations to bag opening and even vessel evacuation. Whether you’re lifting parts, opening bags, or clamping materials, EXAIR’s E-Vacs offer a versatile, maintenance-free solution that optimizes performance while having ZERO moving parts to wear or breakdown, and let’s be honest, mechanical vacuum pumps are always breaking down. Let’s dive into what makes these vacuum generators stand out and explore some of their key variants.

EXAIR E-Vac Vacuum Generator

Our Adjustable E-Vac Vacuum Generators are the ones that typically fall into the “number of other applications” category above. While the In-Line E-Vacs are compact and reliably generate rated vacuum on demand, the Adjustable E-Vacs have some distinct advantages in certain cases:

Larger throat diameter. In-Line E-Vacs have a very tight throat, which generally doesn’t matter if they’re just hooked to Vacuum Cups that’ll be placed on a relatively clean surface. The wider throat of the Adjustable E-Vacs means that they can pass small debris from less-than-pristine surfaces that a Vacuum Cup might lift, or shavings that might fall into a work holding fixture on a machine tool. They can even pass liquids, so they’re sometimes used for small spill cleanup.

Adjustable E-Vac: How it works

Adjustability. It’s right in the name, of course, but it IS a big deal. While you can regulate the supply pressure of almost any compressed air operated device to vary the performance level, you can thread the plug into, or out of, the body of an Adjustable E-Vac to literally put it in a whole new performance band. This is beneficial if you’re picking up, or holding down, pieces of different sizes, shapes, and weights. Just loosen the locking collar, make the adjustment, tighten it back up, and it’s ready for use.

If you have questions regarding our Adjustable E-Vacs, or how to solve any issue with an EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR . One of our Application Engineers would be pleased to help you determine your best solution.

Jordan Shouse
Application Engineer

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In-Line High Vacuum E-Vac Solves Workholding Fixture Problem

Workholding refers to any method of keeping an object in a fixed position while force is exerted onto it. If you’ve ever put something in a clamp or vise to loosen (or tighten) a bolt or screw into it, you’ve performed workholding. In fact, if you’ve ever wrapped a napkin around a cold bottle of your favorite beverage to get a better grip while twisting the cap off, that’s workholding too.

In manufacturing and machining settings, any number of different clamps, fixtures, jigs, chucks, vises, etc., are commonly used for workholding. For efficiency, the main feature of a good workholding device is an easily repeatable setup that can secure the piece quickly, and release it just as quickly. The table of a milling machine, for example, will commonly have t-handle clamps for this.

In addition to mechanically clamping parts, they can also be held in place with vacuum. The basic principle is kind of like an air hockey table, but in reverse: instead of floating the puck on a thin curtain of air being blown out of the holes on the table, it’d be held in place by pulling air back through the holes, to draw a vacuum between the top of the table and the bottom of the puck. Vacuum pump systems can be used for this, but they can get pricey if you don’t already have one (with enough extra capacity) to tie in to. Those pumps have moving parts, so they’re going to need maintenance from time to time as well.

EXAIR E-Vac Vacuum Generators, on the other hand, don’t have any moving parts to wear or electric motors to burn out. They’re compact, they draw rated vacuum as soon as you start supplying compressed air to them, and they drop that vacuum off just as soon as you turn the air off.

For most common workholding applications, we’ll specify an Adjustable E-Vac, for a couple of reasons:

  • Because they’re adjustable, you can quickly dial in different vacuum – and vacuum flow – levels needed to hold parts of different sizes, shapes, and/or weights.
  • They have a large enough throat diameter to pass small amounts of chips or coolant, so the part doesn’t have to be perfectly clean when you place it in the fixture.
The wide throat diameter of the Adjustable E-Vac makes it suitable for applications where small amounts of particulate and/or liquid may be drawn through.

Of course, not EVERY application is a COMMON one…case in point, I had the pleasure of helping a caller from a tool & die company the other day, who wanted to make a fixture to hold a metal block in a V-shaped fixture with two flat surfaces that correspond to the two flat surfaces of the block that won’t be worked on. The idea was to put several holes in each surface, with shallow countersinks for o-rings, so that when the block was set, the o-rings would make a positive seal, and pull vacuum on those holes with an E-Vac. Since there’s a tight seal between the blocks & fixture, and the blocks will be clean & dry, this doesn’t require the chip/coolant passage of an Adjustable E-Vac. And since the cutting & drilling will exert a good amount of force, in several directions, we DO want a high vacuum level to make sure it doesn’t move. At all. No matter what.

For this application, we specified a Model 810023M In-Line High Vacuum E-Vac. It’ll generate 27″Hg worth of vacuum, and in case of any minuscule movement or misalignment of the block, it’ll provide an impressive 2.67 SCFM worth of vacuum flow (to overcome any leakage past the o-rings) and still hold the block in place with 24″Hg.

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

If you’d like to find out more about EXAIR Vacuum Generators for workholding, pick-and-place material handling, vacuum forming/filling/pressing, or any other application where you need any more than a few inches of mercury worth of vacuum, give me a call.

Russ Bowman, CCASS

Application Engineer
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Adjustable E-Vacs For All Kinds Of Vacuum Applications

EXAIR makes three different engineered compressed air products that are capable of pulling vacuum:

  • Air Amplifiers generate a very high vacuum flow (up to 25 times the compressed air flow rate) but not very much vacuum head. This makes them great for fumes, smoke, and airborne dust.
  • Line Vacs generate a moderate vacuum flow and head so they can easily convey bulk solids.
  • E-Vac Vacuum Generators generate a high vacuum head, but not a lot of vacuum flow. They’re commonly used with Vacuum Cups in pick-and-place applications, or a number of other applications where you measure the required vacuum in inches of mercury (the Air Amplifiers’ and Line Vacs’ vacuum heads are measured in inches of water.)

Our Adjustable E-Vac Vacuum Generators are the ones that typically fall into the “number of other applications” category above. While the In-Line E-Vacs are compact and reliably generate rated vacuum on demand, the Adjustable E-Vacs have some distinct advantages in certain cases:

Larger throat diameter. In-Line E-Vacs have a very tight throat, which generally doesn’t matter if they’re just hooked to Vacuum Cups that’ll be placed on a relatively clean surface. The wider throat of the Adjustable E-Vacs means that they can pass small debris from less-than-pristine surfaces that a Vacuum Cup might lift, or shavings that might fall into a work holding fixture on a machine tool. They can even pass liquids, so they’re sometimes used for small spill cleanup.

Adjustability. It’s right in the name, of course, but it IS a big deal. While you can regulate the supply pressure of almost any compressed air operated device to vary the performance level, you can thread the plug into, or out of, the body of an Adjustable E-Vac to literally put it in a whole new performance band. This is beneficial if you’re picking up, or holding down, pieces of different sizes, shapes, and weights. Just loosen the locking collar, make the adjustment, tighten it back up, and it’s ready for use.

With four distinct models to choose from, we can specify one with the vacuum performance and adjustability of range needed for your application. If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
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