Tag: blow off system

What Is a Centrifugal Air Compressor? How It Works and Why It’s Used in Industry

Published on by Tyler DanielLeave a comment

One thing that’s found in nearly every industrial environment is an air compressor. Compressed air is used to power tools, operate packaging and automation systems, run conveyors, control valves, and more. Pneumatic tools remain popular because they’re smaller and lighter than their electric counterparts, offer infinitely variable speed and torque, and can often be safer than electrical devices in harsh or wet environments.

To power these systems, compressed air must first be generated, and that starts with the air compressor. There are two main categories of air compressors: positive displacement and dynamic. Positive displacement compressors trap a given quantity of air in a chamber, then mechanically reduce the volume to increase the pressure. Dynamic compressors raise air pressure by accelerating continuously flowing air with a high-speed impeller. The velocity energy of the air is then converted into pressure energy.

One of the most common dynamic types used in industrial applications is the centrifugal air compressor. In a centrifugal compressor, air enters the center of a high-speed rotating impeller, which can spin at more than 50,000 RPM. The impeller’s blades fling the air outward by centrifugal force, increasing its velocity and pressure. The kinetic energy of the moving air is then converted into additional pressure as it slows down in a diffuser. Centrifugal compressors are generally used where large volumes of air are required. They can handle flows from a few hundred CFM up to 100,000 CFM or more, with most plant installations falling in the 1,000–5,000 CFM range.

According to the Compressed Air Challenge, some of the key benefits of centrifugal air compressors include their ability to deliver oil-free, contaminant-free air, and the fact that they are often supplied as complete packaged systems up to 1,000 HP. They scale well, as the cost per CFM improves as size increases, do not require special foundation requirements, and are ideal for high-volume air delivery.

Of course, there are trade-offs to consider. Centrifugal compressors have limited capacity control options, reduced efficiency at partial load, and their high rotational speeds require precision bearings and specialized maintenance. They also tend to have a higher initial purchase cost compared to smaller positive-displacement units. Despite these considerations, centrifugal air compressors remain a reliable choice for facilities that require large, continuous volumes of clean, oil-free air.

Once your facility’s air is generated, the next step is making sure it’s used efficiently. Compressed air is one of the most expensive utilities in a plant, and any wasted air means wasted energy. That’s where EXAIR’s line of engineered Air Nozzles, Safety Air Guns, Super Air Knives, and Optimization products come into play, helping you get the most from every SCFM your compressor produces. If you’re looking to improve your system’s efficiency or solve a specific application issue, contact one of our Application Engineers. We’ll help you get the most out of your compressed air system from the compressor room to the point of use.

Tyler Daniel

Application Engineer

E-mail: TylerDaniel@EXAIR.com

X: @EXAIR_TD

Image courtesy of the Compressed Air Challenge

Week 3 Back to Basics – Replace Inefficient Blowoffs

Published on by Brian FarnoLeave a comment

In the last post of this series, we talked about finding and fixing leaks in your compressed air system. Many readers found that step especially valuable—leak detection alone can uncover major savings opportunities. Now, it’s time to move on to step three in the Six Steps to Optimizing Your Compressed Air System: implementing engineered solutions.

Engineered solutions (like EXAIR Intelligent Compressed Air Products) are the efficient, quiet, and safe choice.

This is where our Application Engineers can really help. Whether your application calls for Air Knives, Super Air Nozzles, or another one of our engineered products, we can guide you to the right solution. If you already know the consumption rates of your existing setup, we can even help you calculate the savings you’ll see by switching.

Step three is often where customers begin to notice the biggest impact. Replacing an open pipe or a non-engineered blowoff with an engineered solution can drastically reduce compressed air usage. The difference becomes obvious when your compressor cycles less frequently—or in some cases, when you’re able to shut down a secondary compressor altogether.

In the next post of this series, we’ll cover step four: an even simpler way to extend your savings by turning air off when it isn’t needed. Until then, keep working toward a more efficient compressed air system.

Brian Farno, MBA – CCASS Application Engineer

BrianFarno@EXAIR.com
@EXAIR_BF

Customize Your Safety Air Gun to Best Meet Your Needs

Published on by Al WooffittLeave a comment

EXAIR has an extensive line of Safety Air Guns that will meet a variety of applications. Our VariBlast Precision, Compact, Soft Grip, Heavy Duty and Super Blast Safety Air Guns, and TurboBlast will give you a wide range of options to choose from. These options can be expanded on even further through the addition of our Air Gun Accessories. In this blog I want to cover a few of the ways you can customize and personalize your Safety Air Gun to make sure you are getting the most out of our products.

Features & benefits of the new TurboBlast Safety Air Gun

Once you have selected your particular Air Gun, you will want to make sure that you have the right nozzle. Every Air Gun has multiple nozzle options with different force and flow specifications. If your main concern is low sound levels, then the Mini Super Air Nozzle may be the best option. If you need more force, then the 2″ High Power Flat Super Air Nozzle would be preferred. We also have Back Blow Nozzles that are great for blind holes.

In addition to this, there are several different material choices. Zinc-aluminum for general purposes, Type 303 stainless steel for corrosion resistance, Type 316 stainless steel for superior corrosion resistance and mechanical wear, and finally PEEK thermoplastic for non-marring and chemical resistance.

Model 1210 Soft Grip Safety Air is fitted with an EXAIR Super Air Nozzle. We can also supply it with a Rigid Extension and Chip Shield (right).

After you have determined the right nozzle, do you need to add a Chip Shield? If you have the potential for flying debris, and you want to protect your operator, then our Safety Air Guns can be equipped with a durable polycarbonate shield. They are also useful for preventing coolant from splashing back, helping you to avoid a mess. You can see a Chip Shield in action in the video below:

We also have various length extensions for when you need more reach for your blowoff operation. Depending on the Air Gun, we have lengths ranging from six inches to six feet. These are great when used in conjunction with our Chip Shields. If you need something more flexible than a straight extension, our Soft Grip Safety Air Gun can also be used with our Stay Set Hoses. These hose have a ‘memory’ to allow for precise positioning without creeping or bending.

Specifically with our Soft Grip Safety Air Gun, we have a special extension and scraper combination, covered in detail in this blog. The Soft Grip Super Air Scraper is highly effective at removing stubborn debris from various surfaces.

Coiled Hose

Finally, we stock a 12‘ coiled air hose. These are available with 1/8NPT, 1/4NPT and 3/8NPT male end swivel connections. This will help you avoid messy and tangled air lines.

Al Wooffitt
Application Engineer

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Ask Your Application Engineer If An EXAIR Air Knife Is Right For You

Published on by Russ BowmanLeave a comment

Right on schedule with the change in temperature as summer turns to fall, I woke up with a scratchy throat, runny nose, and a bit of fatigue this morning. I weighed my options for relief in the medicine cabinet: pain reliever/fever reducers, over-the-counter cold & flu medication that add cough suppressants, expectorants, and decongestants to the mix, homeopathic remedies with zinc, echinacea, all natural immune boosters, and a jar of honey for my tea or bourbon, depending on the time of day…and my mood. If my symptoms worsen, I can get tested for the flu or COVID, and may be prescribed antiviral medication. In any case, rest and hydration will likely be important factors in my recovery.

Much like my medicine cabinet, the Air Knives section of the EXAIR catalog has a selection of remedies for problems that can be addressed by a curtain of air. If the curtain of air needed is 36″ or less, we can consider any of the three styles of Air Knife we make: Super, Standard, or Full Flow. If it has to be more than that, the Full Flow Air Knives are out (36″ is their max length) but Standard Air Knives come in lengths up to 48″. Super Air Knives give us the most range here; they come in lengths up to 108″, and can actually be coupled together to provide uninterrupted curtains of flow in whatever length is needed.

Super Air Knives (left) come in lengths up to 108″, Standard Air Knives (middle) up to 48″, and Full Flow Air Knives (right) up to 36″.

Standard and Full Flow Air Knives come in aluminum or 303SS. Aluminum is lightweight and suitable for general purpose applications where high heat and corrosive elements are not a factor. Aluminum Air Knives are rated to 180°F. Type 303 Stainless Steel is suitable for mildly corrosive environments, and is rated to 800°F ambient temperatures.

Super Air Knives are available in aluminum and 303SS, as well as 316SS and PVDF. Type 316 Stainless Steel is stronger and more corrosion resistant than Type 303, and offers superior resistance to certain pitting, which makes it the best choice for food, pharmaceutical, and surgical product manufacturers. PVDF (polyvinylidene fluoride) Super Air Knives have Hastelloy C276 hardware and PTFE Shims. They provide superior corrosion resistance in more aggressive situations than Stainless Steel can like, like in electroplating, solar cell and lithium ion battery manufacturing, strong acid & caustic chemical handling, etc.

The first Air Knife developed by EXAIR was the Standard Air Knife (formerly known as the EXAIR Knife) and are still quiet and efficient alternatives to drilled pipes, manifolds with open-ended blowing nozzles, and blower-powered air knives. They use a Coanda profile (more on that in a minute) which causes the airflow to turn 90° from where it exits the linear nozzle formed by the shim between the cap & body. This primary air stream entrains surrounding air from the environment, resulting in a total developed airflow that’s 30 time greater than the compressed air consumption of the Air Knife. This entrainment creates a low velocity boundary layer, which reduces the sound level, but there still is some wind shear produced along the Coanda profile.

Because of the end ports in the relatively small profile of the body, there’s 1/2″ on each end where there’s no flow. Since we identify them by the length of the air curtain they generate, Standard Air Knives are physically 1″ longer than their published length (a Model 2012 12″ Aluminum Standard Air Knife has an overall length of 13″, a Model 2018SS 18″ 303SS Standard Air Knife is actually 19″ long, etc.) Full Flow Air Knives use a Coanda profile as well, but they have rear ports, so there’s full flow (as advertised) from end to end. Here’s more on how the Standard and Full Flow Air Knives work:

Compressed air flows through the inlet (1) to the Full Flow (left) or Standard (right) Air Knife, into the internal plenum. It then discharges through a thin gap (2), adhering to the Coanda profile (3) which directs it down the face of the Air Knife. The precision engineered & finished surfaces optimize entrainment of air (4) from the surrounding environment.

The latest, and greatest generation of engineered Air Knife in EXAIR’s arsenal is the Super Air Knife. As detailed above, they offer the most choices in length & materials. They’re also the most efficient, and quietest. Because the airflow exits straight from the linear nozzle formed by the shim gap between the body & cap, with no wind shear, the low velocity boundary layer produced by the entrainment of surrounding air means the sound level (with an 80psig inlet pressure) is a remarkably low 69dBA at a distance of three feet. Any style (Standard, Full Flow, or Super) Air Knife will perform just fine in just about any application that requires a curtain of airflow. If noise level, and/or operating cost, are on your mind, though, the Super Air Knife is certainly worth considering. With just a few details about the application, we can calculate the difference in operating cost for all three models of a given length, and provide you with the ROI (return on investment) for the Super Air Knife. If you’d like to find out more, give me a call.

Russ Bowman, CCASS

Application Engineer
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