Tag: Adjustable Spot Cooler

Adjustable Spot Cooler Improves Production Of Can Lids

Published on by Russ BowmanLeave a comment

Canned food has been around since the early 1800s, when the French government offered 12,000 francs (I don’t know how much that is in today’s currency, but it sounds like a LOT) to the first person to come up with a way to effectively and affordably preserve food, so the French army could take it with them during Napoleon’s planned conquest of Europe. Nicolas Appert, a candy maker and chef to the rich and famous, had been experimenting with cooking food inside sealed containers and noticed that it didn’t spoil if the seals didn’t leak. So he demonstrated his technique to the powers that be, and walked away with the 12,000 franc prize. It didn’t really pan out for the army because the process was slow & expensive, but canned food became something of a novelty among the aforementioned rich & famous of the day. This WAS the heyday of the Industrial Revolution, though, and food companies quickly advanced the technology for mass production. Today, there are very few food products that you won’t find a canned or jarred version of. In the early days, you had to use a can opener, but today you can find pull tabs on many cans, especially beverages.

Ever since Jimmy Buffett cut his heel on the one on the left in “Margaritaville”, we’ve been drinking from cans with ‘pop tops’ like the one on the right.

A more recent innovation is a peel-off foil seal on the lid that seals the product for freshness, immediately after packaging. It’s then removed by the consumer after purchase, and the container is commonly supplied with a plastic lid that snaps onto the rim.

A container manufacturer uses Model 3925 Adjustable Spot Cooler Systems with Dual Outlet Cold Air Hoses to rapidly cool the freshly heated sealed foil onto metal lids like those that are used for coffee cans. This allows them to move the lids from the heat sealing station to the next process faster.

From left to right: EXAIR Mini Coolers, Cold Guns, and Adjustable Spot Coolers come with Magnetic Bases for instant installation.

Because they generate cold air flow on demand, this is a very common application for EXAIR Vortex Tube Spot Cooler products. With no moving parts to wear or electrical components to burn out, they’re reliable & durable. If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
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Theory of a Dead Man

Published on by jasonkirbyLeave a comment

Georges-Joseph Ranque was born on February 7, 1898, in Ambérieu-en-Bugey, France, to Léon-Joseph Ranque, a railroad engineer. This familial background naturally fostered his passion for physics. He attended the esteemed Lycée Saint-Louis, a selective post-secondary institution, where he furthered his understanding of the subject. Subsequently, he gained admission to École Polytechnique, continuing his academic journey. During his work on an industrial pump, Ranque became intrigued by the Pantone carburetor and discovered what is now referred to as the Ranque effect. This phenomenon serves as the foundational principle behind industrial vortex tubes, where the tangential injection of compressed gas at high velocity results in the creation of two distinct streams: one hot and one cold.

The unique physical phenomenon of the Vortex Tube principle generates cold air instantly, and for as long – or short – a time as needed.

This cold airflow is effectively employed in various industrial applications for spot cooling and enclosure cooling, thanks to its straightforward and dependable nature. The only requirement is a source of compressed air. In 1931, Georges patented his vortex tube, but it did not gain much traction until physicist Rudolf Hilsch revisited the concept. Hilsch enhanced the design, which he referred to as the “Wirbelrohr,” or “whirl pipe” in English. Consequently, the term “Ranque-Hilsch tube” is often used interchangeably with “vortex tube” due to Hilsch’s contributions.

Compressed air enters the tube and flows through a series of nozzles positioned tangentially to the internal counter bore. This nozzle configuration induces the air to rotate in a vortex at speeds reaching up to 1,000,000 RPM. As the air spins, it makes a 90° turn, where a valve at one end permits a portion of the heated air to escape. The remaining air continues down the tube in the inner stream, losing heat before exiting as cold air at the opposite end.

How a Vortex Tube Works

Both streams in a vortex tube rotate in the same direction and at an identical angular velocity. According to the principle of conservation of angular momentum, the rotational speed of the inner vortex is expected to increase. This phenomenon can be effectively illustrated through Olympic figure skating: when a skater extends her arms, her spinning slows down, but as she pulls them in, her rotational speed increases significantly. In the case of a vortex tube, however, the inner vortex maintains a constant speed as it has lost angular momentum. The energy dissipated during this process is released as heat from the hot side of the tube. This heat loss facilitates the cooling of the inner vortex, enabling it to be harnessed for various industrial applications.

The theory behind Vortex Tubes is applied in standard Vortex Tubes as well as in a range of other products designed with specific features tailored to various applications. EXAIR offers a selection that includes Cabinet Coolers, Cold Guns, Adjustable Spot Coolers, Mini Coolers, and Vortex Tubes, all of which function based on this fundamental principle.

 If you have any questions about Vortex Tubes, 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

Cold Fraction Explained

Published on by jasonkirbyLeave a comment

EXAIR has published numerous articles detailing the functionality and applications of Vortex Tubes. This innovative technology, which produces cold air without the use of Freon or mechanical components, is rooted in physical principles and has been known by various names, such as the Ranque Tube, Ranque-Hilsch Tube, and Maxwell’s Demon. Today, it is commonly referred to as the Vortex Tube, capable of generating air temperatures as low as -50 °F (-46 °C) through the high-speed rotation of compressed air. In this article, I will discuss how to adjust the Vortex Tube to achieve varying temperatures and cooling effects, focusing on the concept of Cold Fraction.

The term “Cold Fraction” refers to the proportion of supply air allocated to the cold end of a system. A higher Cold Fraction indicates an increased flow and temperature of the cold air, while a lower Cold Fraction results in diminished cold air flow and temperature.

The performance chart below illustrates how the settings for “Pressure Supply” and “Cold Fraction %” influence the operation of Vortex Tubes. For instance, with an operating pressure of 100 PSIG and a cold fraction set at 20%, the cold side experiences a temperature drop of 123°F, while the hot side sees a rise of 26°F. Conversely, maintaining the same pressure of 100 PSIG but adjusting the cold fraction to 80% results in a 54°F decrease on the cold side and a significant 191°F increase on the hot side.

EXAIR Vortex Tube Performance Chart

In a convection or conduction air cooling application, two key factors must be considered: the air flow rate and the temperature difference between the cooling air and the heated component. It is advisable to begin with the maximum cold fraction; however, you may discover that a slightly reduced flow rate, along with the corresponding lower temperature, could better meet your requirements. The positive aspect of this adjustment is that it does not affect compressed air consumption, allowing you to enhance performance without incurring additional operational costs.

If you have any questions about Vortex Tubes, 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

Super Air Amplifier vs Fan

Published on by Al WooffittLeave a comment

One of the more common applications we work with is cooling. In most instances, the goal is to cool the part as quickly as possible. In order to cool faster, you would think that blowing the coldest air possible would be the best option. Our Vortex Tubes can produce air as cold as -50°F! However, in many instances, more effective cooling will be achieved through larger volumes of air. As long as the ambient air temperature is lower than the target temperature, larger volumes of ambient air will outperform a small volume.

Our Super Air Amplifier is a great option for producing large volumes of laminar (non-turbulent) airflow for minimal compressed air consumption. Using a Coanda profile along with a patented shim, compressed air exits the Amplifier in a manner that generates a low pressure zone, which helps pull in the surrounding ambient air. This creates an amplification ratio of up to 25 times! Due to the laminar output flow having the same speed and direction, it is very effective at removing heat from a target. It also helps keep noise levels down.

The most common, non-compressed air alternative to our Amplifiers is an electric fan. Fans utilize motors and blades to direct air towards their target. When air comes in from behind the fan, the blades push the air forward to the target. This action generates turbulent air flow, as well as a lot of noise. Due to the use of motors, there are parts that can wear out over time, leading to additional maintenance costs over the lifetime of the fan.

Ultimately, when it comes to cooling, what we care about most is how quickly a given solution will get the job done. Is a Super Air Amplifier going to cool faster than a fan? In the video below we put both options to the test. As you will see, the Super Air Amplifier is significantly faster:

If you have a cooling application that you would like to discuss, give us a call!

Al Wooffitt
Application Engineer

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