Laminar vs. Turbulent Flow

If the object you’re blowing off is flat, the laminar air flow from a Super Air Knife is ideal. They come in lengths from 3 inches to 9 feet long.

EXAIR often differentiates between laminar and turbulent flow in relation to our blow-off products. To clarify, laminar airflow is notably more efficient in blow-off applications, as it reduces pressure drops, enhances product displacement, and minimizes noise levels when compared to turbulent airflow. Understanding these distinctions is essential for optimizing performance in various applications.

Laminar flow describes a type of airflow where the velocity and direction remain uniform throughout a designated volume of air. This phenomenon results in air movement that occurs in straight lines, aligning parallel to any solid surfaces present in the area.

Laminar airflow is effective in reducing turbulence. However, the introduction of devices or materials on surfaces can unintentionally create swirls within the workspace. This chaotic turbulent flow can disrupt tasks that require a dust-free environment, leading to potential contamination. Furthermore, obstructions such as items left inside enclosures can exacerbate this issue.

The Super Air Knife by EXAIR serves as a prime example of a product that delivers laminar airflow. This cutting-edge tool offers an efficient solution for tasks such as cleaning, drying, or cooling various components, webs, or conveyors. It produces a steady sheet of laminar airflow that applies a consistent force along its entire length, ensuring optimal performance for a wide range of applications.

Turbulent airflow is characterized by its unpredictable and chaotic fluid dynamics, standing in stark contrast to laminar flow, where fluids move in smooth, parallel layers. In turbulent conditions, the fluid’s speed and direction are in constant flux, leading to the development of eddies and swirls within the flow.

If you have questions about laminar or turbulent airflow, please do not hesitate to reach out.

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

Buy 1, Get 40 Free

Buy one, get one free is a phrase many of us are familiar with. Most of the time it is a good thing; we all like free stuff. What would you say to buy one, get 30 free? Or even 40 free? That’s not far off how our Air Knives perform. They entrain large volumes of ambient air, so for every 1 SCFM of compressed air you are paying for, you are getting 30–40 SCFM of additional free ambient entrained air.

So how are our Air Knives able to do this? We explain this phenomenon in more detail in this blog here, but in summary, a Super Air Knife takes advantage of the Venturi Effect. Named after Giovanni Venturi, who found out that when you increase the speed of a fluid through an orifice, the surrounding fluid will move along with it. This creates a region of low pressure, and the faster the speed, the lower the pressure. With low pressure, the air around rushes in to fill that gap and join the airstream. The quantity of ambient air that gets ‘pulled’ into the airstream is entrained air, or free air.

The engineered surface of the Super Air Knife is designed to minimize as much loss in air speed as possible, which maximizes the amount of free air that is being entrained. The ratio between free air and compressed air used is called the amplification ratio. Super Air Knives have an amplification ratio of 40:1, with our Standard Air Knives having an amplification ratio of 30:1. For comparison, a pipe with holes drilled will have an amplification ratio of between 2:1 and 5:1. As you can see, with a Super Air Knife you are getting a much better deal on your compressed air usage.

This additional free air adds more mass, which allows the Super Air Knife to do more work. You will get a harder hitting force than a comparable product while using less compressed air. This makes Super Air Knives especially good for cooling and drying applications, where moving large volumes of air is ideal.

EXAIR Intelligent Compressed Air Products such as (left to right) the Air Wipe, Super Air Knife, Super Air Nozzle, and Air Amplifier are engineered to entrain enormous amounts of air from the surrounding environment.

It’s not just our Air Knives that take advantage of the Venturi effect to produce large amplification ratios. Many of our products are designed with efficiency in mind, including our Air Amplifiers, Air Wipes, and Air Nozzles and Jets, to name a few. If you would like to discuss how an EXAIR engineered compressed air product can amplify your process, then give us a call!

Al Wooffitt
Application Engineer

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Twitter: @EXAIR_AW

From Field to Market: How EXAIR Helps Streamline Vegetable Processing

Homonyms are words that are pronounced and spelled the same but have different meanings.  In this blog, I will cover the word lettuce.  One meaning is the leafy vegetable and the other is money.  And I like to save both.  I have an agriculture application that I would like to share where EXAIR was able to supply different products to help save lettuce. 

PowerStream Liquid Nozzle

When vegetables come from the field, they need to be cleaned and packaged for delivery to grocery stores.  The first thing that they need to do is to wash the leaves to remove dirt, compost, and bugs.  They had drilled pipes to spray water onto the leaves, using a lot of water. They were looking to do it more economically. The vegetable packing house purchased the EXAIR PowerStream Liquid Nozzles, model DL8075SS, to do the washing.  These stainless steel nozzles were mounted on a manifold to spray water onto the lettuce leaves.  With the PowerStream nozzles, we can break the water into smaller droplet sizes to increase coverage and reduce water requirements.  Thus, saving money.

The next step would be to dry the lettuce.  They were using a blower-powered air knife, but they could not remove all the insects as it was not powerful enough.  Also, by blowing hotter air which was created by the blower, lettuce would start to brown much quicker.  To improve, they purchased a model 110036SS Stainless Steel Super Air Knife.  The Super Air Knife is an efficient, powerful way to blow compressed air.  With a 40:1 amplification ratio, it will draw in 40-parts of ambient air to 1-part compressed air.  From our Super Air Knife, we blow ambient temperature air, add mass to give a much higher force to remove the water and the insects, and save on compressed air consumption. 

To reduce spoilage, you must have the proper equipment.  For this company, they were able to improve their process to increase production.  And by utilizing less water and less compressed air, they were able to increase profit.  If you would like to improve your processes in packing houses, EXAIR has a variety of products that can help you.  You can contact an Application Engineer to discuss.  For the company above, more lettuce out the door meant more lettuce in their pockets. 

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

Photo of Vegetables by akadarceePixabay content license.

Super Ion Air Knife Overview

A collection of industrial electronic components including a sensor, cables, mounting brackets, a pressure gauge, and a control box.
Gen4 Super Ion Air Knife Kit

Static electricity is a prevalent issue in various manufacturing settings, manifesting in several ways, such as shocking workers, causing materials to adhere, tear, or jam, and interfering with sensitive electronic devices. If you have experienced static problems in your workplace or home, you may have observed that these issues are more pronounced in colder, drier conditions. This phenomenon occurs because lower humidity levels reduce the amount of water vapor in the air, which is essential for dissipating electrical charges. Consequently, with diminished moisture, the potential for higher electrical charges increases.

Our Gen4 Super Ion Air Knives are a central element of this promotion, engineered to effectively remove static electricity from a variety of surfaces, such as plastics, webs, and sheet materials. By employing a laminar airflow, these air knives efficiently eliminate static, dust, and other contaminants from surfaces.

EXAIR Super Ion Air Knife

This cutting-edge technology not only accelerates production rates but also enhances product quality and guarantees exceptional surface cleanliness. The integration of these air knives into your processes can lead to significant improvements in operational efficiency.

The Gen4 Super Ion Air Knife effectively disperses static-eliminating ions over a distance of up to 20 feet, with adjustable airflow that ranges from a powerful blast to a gentle breeze. This device operates without shock and features no moving parts, ensuring reliability and ease of maintenance. It requires only 3.7 SCFM of compressed air per foot at a pressure of 5 PSIG, making it an efficient choice for various applications.

A Super Ion Air Knife used for static control in various applications, featuring a long, flat design with a control panel at the top and a book or printed material positioned in the front.
Available in lengths from 3″ to 108″, the Super Ion Air Knife dissipates even high static charges quickly.

In addition to its functional benefits, the Gen4 Super Ion Air Knife operates at a remarkably low sound level of 50 dBA, which is suitable for most environments. This combination of performance and quiet operation makes it an ideal solution for effectively managing static electricity in diverse settings.

If you have any questions about Gen4 Super Ion Air Knives, or anything regarding EXAIR and our products, please do not hesitate to reach out. We would love to hear from you!

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