Tag: Air Pressure Amplifier

Venturi Effect in Use

Published on by jasonkirbyLeave a comment

The Venturi effect describes the phenomenon where a fluid, such as air or water, accelerates as it passes through a constricted section, resulting in a decrease in pressure. This occurs because the fluid is drawn into the narrower area, and the increase in velocity leads to a corresponding drop in pressure. The effect is named after Giovanni Battista Venturi, who first articulated this principle in 1797.

A perfect example of the Venturi Effect can be found in our Air Amplifiers. Compressed air enters through the air inlet and flows into an annular chamber, where it is accelerated through a small ring nozzle. This high-velocity primary airstream follows the Coanda effect, guiding it toward the outlet. As a result, a low-pressure zone forms at the center, drawing in a significant volume of surrounding air into the primary flow. The mixture of the primary airstream and the surrounding air is then expelled from the Air Amplifier at a high volume and velocity.

The Venturi Effect is represented in amplification ratios. A ratio represents the relationship between two quantities, indicating how many times one value is contained within another. In the case of the Super Air Knife, this ratio illustrates the volume of ambient air that is drawn in alongside the primary flow of compressed air. With an impressive amplification ratio of 40:1, the Super Air Knife incorporates 40 parts of ambient air for every single part of compressed air, making it one of the most efficient air-operated knives available. This addition of mass enhances the device’s ability to deliver a powerful force, enabling it to perform more effectively in various applications.

The Venturi effect is integral to various EXAIR products designed for cooling, drying, and cleaning, alongside our vacuum generators. If your facility has a process that could benefit from an Intelligent Compressed Air solution, please reach out to us. We would be pleased to discuss your specific application and develop a solution that not only lowers your compressed air expenses but also enhances worker safety.

Jason Kirby
Application Engineer
Email: jasonkirby@exair.com
Twitter: @EXAIR_jk

Intelligent Compressed Air: Two Different Products Called “Air Amplifiers”

Published on by Russ BowmanLeave a comment
A 2psi change in compressor discharge pressure equates to a 1% change in compressor power consumption.

They say that necessity is the mother of invention, so it’s no coincidence that mechanical means of compressing air came about in the early days of the Industrial Revolution, eventually becoming known as the “4th Utility” along with electricity, water, and gas. For most of the 20th Century, compressed air system pressure was commonly generated in the neighborhood of 100psig, although many modern industrial air compressors can be operated at 160 to 200psig. Operating an air compressor at higher discharge pressure increases the cost of operation, though, so it’s in EVERYONE ‘S best interests to run compressed air systems at the lowest pressure possible, that still gets the job done for all the air-operated gear in the facility.

So, what if most of your compressed air loads operate at 80-100psig, but one (or a handful) needs 120psig? Or 160psig? Or even higher? Increasing your compressor discharge pressure from 100psig to 160psig means you’re using 30% more power to run the compressor. That’s a LOT for one (or a handful) of operations.

Good news: the laws of physics say that pressure is the amount force applied to a specific area…as in pounds(force) per square inch, or psi. So, if we apply a certain pressure to a large diameter piston, and attach that with a shaft to another smaller diameter piston, the amount of force doesn’t change, but the area does, so the pressure on the other side of the smaller piston HAS to:

Let’s say the primary pressure (P1) is 100psi, and the primary piston (D1) is 4″ in diameter, with a surface area of 12.56 in2. That means the force applied to the primary piston (D1) is : 100 lbf/in2 x 12.56 in2 = 1,256 lbf.
This is the same force applied to the air on the other side of the secondary piston (D2), which has a diameter of 2″ and a surface area of 3.14 in2. Since pressure is force divided by area, that 1,256 lbf applied to 3.14 in2 results in a secondary pressure (P2) of 400psi.

This is the basic theory behind how air (pressure) amplifiers – also known as booster regulators – work. Essentially, you’re trading compressed air flow (into the larger cylinder) for pressure. Now, if EVERYTHING you operate needs higher pressure, the best way to do that is to increase the compressor discharge pressure. But if you only have one, or a few, loads that need higher pressure, the increase in air consumption for those loads is likely less costly than compressing the air to a higher pressure than is needed for the majority of your loads.

The other type of air amplifier is the one that EXAIR manufactures – it’s an air FLOW amplifier, and here’s how it works:

In this case, we’re trading pressure for flow, and getting a much higher total developed air flow rate than just the amount of compressed air it uses. Not only does the entrained air make them incredibly efficient, it also develops a low-velocity boundary layer that attenuates the sound level of the total air flow. They can be used for cooling, drying, cleaning, ventilation, fume exhaust, and even material conveying, especially if the material to be conveyed is very light, or already airborne.

With (16) models to choose from, EXAIR Air Amplifiers are a quick and easy way to provide a tremendous amount of cooling air flow from a compact, lightweight product.

EXAIR Air Amplifiers come in a range of sizes, from 3/4″ to 8″. Super Air Amplifiers are lightweight, durable aluminum, and Adjustable Air Amplifiers are available in aluminum or 303SS. If you’d like to find out more about them, give me a call.

Russ Bowman, CCASS

Application Engineer
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Custom Super Air Amplifier

Published on by Jordan T ShouseLeave a comment

A customer called in looking to incorporate some more airflow to help materials flow properly through their processing line. This line included several legacy machines, so we had to get creative to fit something with in the system in place. It just so happened there were several 3/4″ FNPT ports in the sections where the increased air flow was needed!

So we came up with a 3/4″ Super Air Amplifier, 120020. But rather than the typical smooth OD outlet we extended it a bit and put a 3/4″ MNPT thread on the end! See it below next to a photo of the 120020.

Right side is a stock 120020, and to the left is the Custom 120020 with a 3/4″ MNPT threaded outlet!

EXAIR’s Super Air Amplifiers achieve air amplification ratios ranging from 12:1 on our smallest units and up to 25:1 for our 4” and 8” models. EXAIR’s Super Air Amplifiers utilize a patented shim design to maintain critical positioning of component parts. This allows a precise amount of compressed air to be released at exact intervals toward the center of the Super Air Amplifier. This creates a constant, high velocity outlet flow across the entire cross-sectional area. Free, ambient air is entrained through the unit, resulting in high amplification ratios. The balanced outlet airflow minimizes wind shear to produce sound levels far lower than other similar air movers.

Super Air Amplifiers are supplied with a .003” thick shim that is ideal for most applications. Flow and force can be increased by replacing the shim with a thicker .006” or .009” shim. The flow of air is also controlled by adjusting the input pressure supplied to the amplifier. Higher pressures increase both the force and flow, while lower pressures decrease both force and flow. All Super Air Amplifiers are available in kits that come with a shim set as well as a suitably sized pressure regulator and auto-drain filter.

EXAIR has a solution for you if you need to move A LOT of air, even if we need to customize it to fit perfectly in your application. Also, this custom product only took a few weeks to produce, so delivery times are still reasonable!  Reach out to an Application Engineer today if you have an application that you believe could be served with a low-cost, simple solution!

Jordan Shouse
Application Engineer

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Air Amplifiers, Pressure vs Flow

Published on by Jordan T ShouseLeave a comment

At least once a week I get a call about our line of Super Air Amplifiers regarding increasing the air pressure on a compressed air system. Well, the Super Air Amplifiers are perfect at increasing the volume of air you exhaust into an application by increasing the output air flow through entrainment of ambient air along with the primary compressed stream! So, they will increase volume for exhausting to atmosphere, but they do not increase your compressed air system pressure for an application.

But, let’s break the two things down a little further!

EXAIR Super Air Amplifiers!

EXAIR Air Amplifiers are a low-cost way to move air, smoke, fumes and light materials. These Air Amplifiers use the Coanda effect to create a low pressure area which draws in surrounding air to efficiently deliver a high volume of air to a target. Using a small amount of compressed air as their source, Air Amplifiers are among the most efficient products within EXAIR’s entire product line. EXAIR Air Amplifiers will create output flows up to 25 times their air consumption rate and deliver it at a high velocity. The entrainment of outside air amplifies the total volume of air at the output, which also increases force, cooling ability and circulation.

Air Amplifiers use the Coanda Effect to generate high flow with low consumption.

EXAIR’s Air Amplifiers have no moving parts, assuring maintenance-free operation. Fine-tuning flow, vacuum and velocity are easily controlled by regulating the input pressure. For gross adjustment of air flow and vacuum an internal shim is used to increase or decrease the internal “air gap” that the compressed air flows through. Both the vacuum and discharge ends of the Air Amplifier can be ducted, making them ideal for drawing fresh air from another location, or moving smoke and fumes away from an application.

Pressure Boosters

When folks first call in about Air Amplifiers, they generally have in their mind the concept of a pressure booster. Pressure boosters, by comparison, are completely different and are typically more complex systems involving motors or air cylinders in conjunction with feedback and operation controls. Their main job is to increase a baseline pressure in a system to keep low pressure situations from occurring within high value systems or for an unusual case of a pneumatic application that requires pressure higher than the facility, system pressure. For example, in robotic spray booths, the robots and valves require 50 PSIG but if they drop below 20 PSIG, the system can damage itself. A pressure booster can be installed to keep lower pressure systems maintained at a higher pressure for application needs. The systems on which pressure boosters are used tend to be more “closed loop” where a static pressure can be maintained. If a dynamic (moving) higher pressure is required for an application, a booster air compressor intended only for that application may be used to keep the entire facility pressure from having to be raised only to accommodate the one application.

It is my genuine hope that the above explanation regarding EXAIR Air Amplifiers versus air pressure amplifiers (Boosters) is helpful. If you have questions regarding EXAIR Intelligent Air Products please contact myself or one of our Application Engineers as we are always ready to help.

Jordan Shouse
Application Engineer


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