In most “general” blowoff applications, the conical airflow pattern from a standard round shaped nozzle is ideal when trying to remove dust or light debris from the surface of a part or material. However in certain applications, a focused, laminar flow of air is required to produce the desired result, such as cleaning peanut butter from a fill nozzle or ejecting parts in a stamping operation.
EXAIR manufactures our 1″ Flat and 2″ Flat Super Air Nozzles, which provide a 1″ and 2″ (respectively) wide, forceful stream of high velocity, laminar airflow while consuming only a small amount of compressed air. Both the 1″ and the 2″ are available in Zinc Aluminum alloy, rated up to 250°F (121°C), or 316 Stainless Steel construction, rated up to 1,000°F (538°C)
Their unique design incorporates a specially designed, replaceable shim, to maintain a critical gap between the cap and body, resulting in the focused airflow. They are shipped from stock with a .015″ shim installed.
Using the optional shim kit, the shims can be changed out to .005”, .010” or .020”, which allow you to increase or decrease the force and flow by either opening or closing the gap, providing more or less force and flow to meet the demand of the application.
(Here’s a short video showing how easy it is to change out the shims)
We also offer our High Power versions of these nozzles which feature a thicker shim installed (0.025″) for applications requiring higher thrust and velocity.
If you have an application you would like to discuss or to see how the Flat Super Air Nozzles might improve your process, give me a call, I’d be happy to help.
In the world of compressed air blow off solutions, there are a number of options which customers must consider. Should the plant maintenance personnel configure something on-site? Is there a low-cost option available from a catalog warehouse? Or, is there an engineered solution available – and if there is, what does this even mean?
Ultimately, the exercise in comparing these options will help select the option best for the application and best for the company. In order to make these comparisons, we will consider each option based on the following attributes: Force, sound level, safety, efficiency, repeatability, and cost. These are the factors which impact the ability to perform as needed in the application, and effect the bottom line of the company
Blow off applications require a certain amount of force in order to perform the desired task. If the blow off is in a bottling line, for example, we will aim for a lesser force than if blowing off an engine block. But, no matter the application need, we will want to consider the ability of the solution to provide a high force, high impact blow off. Homemade and commercially mass-produced nozzles produce low-to-mid level forces, which translates to a need for more compressed air to complete a task. Engineered nozzles produce high forces, minimizing compressed air use.
Have you ever been to a concert and felt your hearing reduced when you left? This can be the case for personnel in industrial environments with unregulated noise levels. Homemade or non-engineered blow off solutions carry the risk of increased sound levels which are outside of the acceptable noise level limits. EXAIR engineered nozzles, however, are designed to minimize sound level for quiet operation and continual use.
Workplace safety is a serious matter for everyone from shop floor personnel to executive management. Whether you’re working with or near a compressed air operated device, or your making decisions for your company which have to do with the compressed air system, safety is undoubtedly a priority. Unfortunately, homemade and commercially available nozzles normally fail to meet OSHA standards for dead-end pressure requirements (OSHA Standard 29 CFR 1910.242(b)). This means that these solutions can pose a risk of forcing compressed air through the skin, resulting in an embolism which can cause severe harm or even death.
EXAIR nozzles, however, are designed to NEVER exceed dead-end pressure limits and to provide an escape path for airflow in the even the nozzle is blocked. This safety aspect is inherent in ALL EXAIR designs, thereby adding safety to an application when an EXAIR product is installed.
Compressed air is the most expensive utility in any facility. Energy enters as an electrical source and is converted into compressed air through a compressor where up to 2/3 of this energy is lost as heat. The resulting 1/3 of converted energy is then piped throughout a facility as compressed air, where up to 1/3 of the air is lost to leaks. With this in mind, maximizing the efficiency of a nozzle solution becomes imperative. A homemade solution or commercial nozzle does not maximize the use of the compressed air. The result is a need to increase flow or increase pressure, both of which result in higher energy costs.
EXAIR nozzles are designed for maximum force per CFM. This means that any of our nozzles will produce the highest force at the lowest possible compressed air consumption. This, in turn, reduces demand on the compressed air system and allows for a lower energy requirement. Less energy demand means less energy costs, which goes straight to the bottom line of your company.
When installing a nozzle solution, it is important to have the same force and flow from each unit. If a solution needs to be replicated, balanced, or adjusted in any way, having various forces and flows from a homemade setup will induce difficulty and could make changes impossible. Line speed or volume increases may not be possible due to variance in the output flow and forces from homemade setups, but an engineered solution will produce the same output every time. This means you can adjust the nozzles as needed to achieve the perfect solution in your application.
For many customers and businesses, the most important aspect of any solution comes down to cost. Will the solution work? And, how much does it cost? When it comes to a homemade or commercial blow off solution, it may or may not work, and it will have a low purchase cost. But, the purchase price isn’t the whole story when working with compressed air. The real cost of an item is in the operation and use. So, while a homemade solution will be cheap to make and install, it will be EXPOENTIALLY more expensive to operate when compared to an engineered solution. An excellent example is shown above. An open copper tube is compared to an EXAIR model 1102 Mini Super Air Nozzle. The copper tube cost only a few dollars to install, many times less than the EXAIR nozzle, but it costs almost two THOUSAND dollars more to operate in a year. Translation: Install a cheap blow off solution and pay for it in utility costs.
EXAIR nozzles and blow off solutions are engineered for maximum force, lowest possible noise level, OSHA safety compliance, maximum efficiency, and maximum repeatability. These factors allow for options which not only solve application problems, but also do so with the lowest total cost possible. If you have an application in need of a blow off solution, feel free to contact our Application Engineers. We’ll be happy to help. And, if your curious about the benefit of our products in your application, consider our Efficiency Lab. We will test your existing setup next to our recommended EXAIR solution and provide the impact to your bottom line.
EXAIR manufactures a variety of Air Nozzles and Jets to safely, efficiently and effectively blow compressed air. There are many different styles that can best fit specific applications. In this blog, I am going to discuss the EXAIR Air Jets. They are designed to entrain a high volume of ambient air to give a moderate blowing force. Similar to the Air Amplifiers, these miniature devices use very little compressed air to achieve an effective blowing for removing debris, drying parts, or cooling hot products. EXAIR manufactures two different styles, the High Velocity Air Jet and the Adjustable Air Jet.
The Air Jets use a Coanda profile for blowing. The Coanda effect was named after a Romanian aerodynamic pioneer, Henri Coanda who discovered a fluid flow phenomenon. He stated that “a jet of fluid emerging from an orifice to follow an adjacent flat or curved surface and to entrain fluid from the surroundings so that a region of lower pressure develops” (1). Since air is a fluid, it will react in the same manner. The EXAIR Air Jets create a high velocity air stream along an engineered profile. So, as the air “hugs” the profile, a low pressure is created which will draw in ambient air. The unique design of the Air Jet utilizes a ring jet of compressed air to produce that low pressure at the entrance, entraining the surrounding ambient air. This makes the Air Jet very efficient as it utilizes more ambient air than compressed air.
Depending on the environment or application, the Air Jets come in two types of material; brass and stainless steel. The High Velocity Air Jets use a shim to set a gap. The gap can be changed by installing a different thickness of shim to increase or decrease the blowing intensity. These shims in conjunction with a regulator gives versatility for a wide range of applications. If the desired blowing force needs to be changed for different types of products or flexibility is required “on the fly”, the Adjustable Air Jet would be recommended. It has a micrometer gap indicator to set the desired result. By twisting the plug of the Adjustable Air Jet, you can get output flows from a gentle breeze to a blast. What makes both Air Jets unique is the design. They meet the OSHA standard for noise level and dead-end pressure. If you block the output of the Air Jets, the pressure will not exceed the OSHA safety requirement for dead-end pressure. Also, the inlet and/or outlet can both be ducted for remote positioning.
Our accessories can make the Air Jets easier to use. We have Stay Set Hoses for easy connections and maneuverability. The Stay Set Hoses come in a variety of lengths from 6” (152mm) to 36” (915mm) and once you set the position, the Stay Set Hose will keep the Air Jet stationary even during blowing. You can add a Magnetic Base with the Stay Set Hose and Air Jet to mount the blowing unit right to a metal fixture. It has a 100 lb. (45.5Kg) pulling force to keep the Air Jet from moving until you need to move it. The bases come with a ¼ turn shut-off valve and in a single or dual output configuration. In addition to the above accessories, we also offer a model 9040 Foot Pedal valve for operator control of the duration of blowing with their foot, allowing the use both of their hands.
With the cost to make the compressed air utility being so high, it is important to use it as efficiently as possible. The High Velocity Air Jet and Adjustable Air Jet have the ability to give you effective blowing for removing debris, drying parts, or cooling objects without using a large amount of compressed air. With the accessory items included, you can set up an improved blowing station that will be effective, quiet, and efficient for your operators. The Air Jets are flexible and adaptable to be used in numerous types of blowing applications. If you have any questions about the Air Jets or if you would like to discuss any applications, you can contact an Application Engineer at EXAIR.
A casting company used a die casting process to make large aluminum panels. In their operation, a two-part die would clamp together and be filled with hot liquid aluminum. Once the panel was formed and cooled, the die would open to release the part. Before the next panel was die casted, they would use a home-made cart to cool and clean the dies. The cooling was done first by spraying water onto the surface, then compressed air was used to dry the dies. When they started to use their home-made cart in their process, they noticed that the air pressure would begin to drop in their facility. Other locations in the plant started having problems with their pneumatic equipment. They were using too much compressed air during the drying period; so, they contacted EXAIR to see if we could help reduce the amount of compressed air to dry the dies.
To explain a little more about the home-made cart, it was made from a 1” square piece of tubing that was bent in a U-shape. The dimension of the cart was about 40” long and 24” high. Across the top was a piece of extruded aluminum spanning the two ends of the U-shape tubing. This portion of the cart would supply the water to the liquid nozzles. The liquid nozzles hung vertically down from the extruded aluminum at designated heights to target certain areas of the dies. The U-shaped square tubing was used to supply the compressed air to the blow-off nozzles. The compressed air inlets were welded onto each end of the 1” square tubing. Across the bottom of the cart, the 1” square tubing had 38 holes that were drilled and tapped to 1/8” NPT (19 tapped holes on each side). The blow-off nozzles were 1/8” pipes with the ends smashed (reference picture below). They were made to different lengths to get as close to the die for maximum blowing force. The entire home-made assembly was attached to a robotic fixture with a cam to move the large cart between the dies. In applications using “smashed” pipes, they are very easy and inexpensive to make. But, as this customer found out, they use way too much compressed air and they are not as effective in blowing-off or drying.
The customer above was limited to modifications to the home-made cart. It was already configured with the robot features and cam to hit the targeted areas. So, I recommended the model HP1126, 1” High Power Flat Super Air Nozzle. It has a 1” wide air stream that is very similar to the flow pattern of the 1/8” smashed pipe. But unlike the smashed pipe design, the model HP1126 nozzle can accomplish so much more. One of the biggest differences is that the EXAIR nozzles use much less compressed air. (The initial reason for contacting EXAIR). With the engineered design of the nozzle, it can entrain large amounts of ambient air which means that less compressed air is required. For a 1/8” NPT smashed pipe, it can use close to 70 SCFM of air at 80 PSIG – each!
The model HP1126 only requires 17.5 SCFM at 80 PSIG. That is a difference of 52.5 SCFM per nozzle. With 38 nozzles being used on this home-made cart, that equates to a total savings of 1,995 SCFM of compressed air. By simply replacing the 1/8” smashed pipe to a model HP1126 with a shorter nipple, their facility was able to save much compressed air and maintain the pneumatic requirements in the other work areas.
The customer was extremely happy with the air savings, but they asked about the amount of force that the model HP1126 can supply. It was important in their process to remove any residual water from the dies. The reason for the blow-off pipes to be so close to the die was to try and increase the blowing force. The best way that I could explain to them was by using an example of a garden hose. (Reference a blog by Neal Raker “Sometimes Back Pressure is Good; Sometimes it is Bad“). The garden hose is attached to a spigot outside your house. As you open the spigot to supply water through the hose, the water will flow out of the hose at a slow velocity; not very strong. When you place your thumb partially over the end of a garden hose, you restrict the flow and increase the force. Now, you can reach the second-floor windows of your house to clean. With a lack of restriction at the end of the pipes, the air pressure will drop quickly as it travels through the long square tube and through the 1/8” pipe extensions. By the time the compressed air reaches the blow-off site, the pressure is much lower; thus, reducing the effectiveness of removing the water.
The EXAIR nozzles work like your thumb on the hose. The usable pressure is increased at the HP1126 nozzle, instead of a point much further upstream. By increasing the pressure at the point-of-use, the effective velocity and force is much stronger. In addition to this, they can now move the nozzles away from the die surface; in case of any “hiccups” in moving the cart in and out of the dies and eliminating any marring of the surfaces.
Once they installed the 38 pieces of the model HP1126 nozzles onto their cart, the first thing that they noticed was the amount of noise reduction. The model HP1126 only has a noise level of 82 dBA at 80 PSIG, compared to a noise level of an open pipe which is over 100 dBA. By replacing the flattened nozzles with the EXAIR nozzles, this company was able to…
1. reduce air consumption
2. keep the other areas of the plant operating by conserving compressed air at this location
3. reduce the noise level and
4. increase the effective blowing force
If you find that by using your blow-off/drying system, your pneumatic machines under-perform, or the low-pressure alarms are triggered, or you have to turn on an auxiliary compressor, you should contact an Application Engineer at EXAIR to see if we can optimize your compressed air devices. These EXAIR engineered nozzles can remove many issues in your system as it did with the casting company above.
I wrote a blog a few weeks ago about increasing efficiency with EXAIR Super Air Nozzles. In the application for that blog we used engineered nozzles to place open pipes, resulting in an efficiency increased of ~65%. This week’s installment of efficiency improvements boasts similar figures, but through the replacement of misused liquid nozzles rather than open pipe.
The image above shows a compressed air manifold with a number of nozzles. BUT, the nozzles in this manifold are not compressed air nozzles, nor do they have any engineering for the maximization of compressed air consumption. These are liquid nozzles, usually used for water rinsing.
In this application, the need was to blow off parts as they exit a shot blasting machine. When the parts exit the shot blasting process they are covered in a light dust and the dust needs to be blown away. So, the technicians on site constructed the manifold, finding the liquid nozzles on hand during the process. They installed these nozzles, ramped up the system pressure to maintain adequate blow off, and considered it finished.
And, it was. At least until one of our distributors was walking through the plant and noticed the setup. They asked about compressed air consumption and confirmed the flow rate of 550 m³/hr. (~324 SCFM) at 5 BARG (~73 PSIG).
The end user was happy with the performance, but mentioned difficulty keeping the system pressure maintained when these nozzles were turned on. So, our distributor helped them implement a solution of 1101SS Super Air Nozzles to replace these inappropriately installed liquid nozzles.
By implementing this solution, performance was maintained and system pressure was stabilized. The system stabilization was achieved through a 61% reduction in compressed air consumption, which lessened the load on the compressed air system and allowed all components to operate at constant pressure. Calculations for this solution are shown below.
Compressed air consumption of (9) model 1101SS @ 5.5 BARG (80 PSIG): 214 m³/hr. (126 SCFM)
Total compressed air consumption of 1101SS Super Air Nozzles:
Air consumption of 1101SS nozzles compared to previous nozzles:
Engineered air nozzles saved this customer 61% of their compressed air, stabilized system pressure, improved performance of other devices tied to the compressed air system, and maintained the needed performance of the previous solution. If you have a similar application or would like to know more about engineered compressed air solutions, contact an EXAIR Application Engineer.
An overseas company manufactures brazed plate heat exchangers. This type of heat exchanger has a series of corrugated plates that are stacked onto each other. It is designed to create a turbulent flow for better heat transfer in a very compact size. The plates inside the heat exchanger are made of 321 stainless steel which is basically a 304 type of stainless steel but with a titanium stabilizer. This company would receive plain sheets of stainless steel material that were stacked on each other in a column. The dimensions of the plates were as follows: 305mm wide by 520mm long with a thickness of 0.5mm (12” Wide X 20.5” Long X 0.02” thick respectively). Each sheet weighed 635 grams (1.4 lbs.). They would set a stack of the stainless-steel sheets at the beginning of a press machine. The press machine would form the corrugated design into the face of the sheet. They were using a pick-and-place vacuum system to lift one sheet at a time to place inside the press. They started having problems with their process when occasionally two or three sheets would stick together. The underlying sheet could either fall onto the floor which would bend the sheet or be stacked inside the press which would cause an improper corrugation. Both issues were causing much scrap as well as downtime in their process .
They contacted EXAIR to find a way to improve the efficiency of their process. They wondered if static could be causing the “sticking” issues. Generally, static forces are really noticed with sheets made of plastic or non-conductive materials. The stronger the static force, the more issues with sticking and misalignment. EXAIR does offer Static Eliminators to remove static forces in applications just like this. But, with plain metal sheets, static is not a problem as the ions are able to balance themselves.
Typically, the main cause for metal sheets to “stick” together is surface tension. Liquid like water has a strong affinity to itself within the molecular structure, called cohesion, and to the surface that it lies on, called adhesion. The cohesion plus the adhesion to the metal surface can have a strong enough force to overcome the weight of the sheets. To break the surface tension, an additional force is required. An example of surface tension is with nylon tent material. The surface tension of water is strong enough to keep rain drops from penetrating the fabric. If you break the surface tension by touching the tent material, the surface will start to leak water. The same goes for the thin sheets of metal. We just need to break the surface tension to allow the sheets to separate.
I recommended two pieces of the model 1122, 2” Flat Super Air Nozzles. This nozzle gives a flat air pattern to force air between the sheets. Surface tension is based on force over length. Once the sheets start to separate, the contact length will decrease thus reducing the “sticking” force caused by surface tension. In this application, the amount of cohesion and adhesion forces caused by surface tension were unknown. Oil, water, and other liquids have different surface tensions which would require different amounts of blowing forces. To ensure the proper amount to separate the sheets, I recommended the shim set, model 1132SS.
The shims have different thicknesses that can be installed easily into the 2” Flat Super Air Nozzle to change the amount of blowing force. In conjunction with a regulator, this customer could “dial” in the proper amount of force required to counteract the surface tension from any type of liquid that may be on the surface of the sheets. I had them mount one nozzle at two different corners to help “peel” the sheets apart. The customer also tied in a solenoid valve into the compressed air system to cycle on the 2” Flat Super Air Nozzles only during the time when the vacuum system wanted to grab the top sheet. This reduced the amount of compressed air needed for their operation. After the installation, the procedure ran smoothly without downtime and scrap waste.
If your application is creating scrap and downtime caused by sheets sticking together, EXAIR has many types of products to help eliminate this. Whether the “stickiness” is caused from static or liquid adhesion, an Application Engineer can direct you to the best product to eliminate the “stickiness”. For the overseas company above, we were able to apply a sharp flat burst of air to overcome the surface tension between the sheets.
International Application Engineer
EXAIR’s Engineered Air Nozzles and Air Jets provide a simple solution to lower compressed air usage and reduce noise levels for compressed air blowoff operations.
Why Air Nozzles and Jets – When compared to commonly used open copper tubes or pipes, compressed air savings can be as high as 80%. And with less compressed air, sound levels are greatly reduced. A 10 dBA noise level reduction is typical. All EXAIR Air Nozzles and Jets meet the Occupational Safety and Health Administration (OSHA) maximum dead end pressure and sound level exposure requirements. They also carry the CE mark.
EXAIR Nozzles are engineered to take advantage of the Coanda effect to amplify the airflow up to 25 times or more. Compressed air is ejected through the small orifices and surrounding air is entrained into the main stream. The resulting air stream is a high volume, high velocity blast of air at minimal consumption. EXAIR manufactures many styles, from the very small, but powerful Atto Super Air Nozzles, to the largest 1-1/4 NPT Super Air Nozzle. Also offered are 1″ and 2″ wide Flat Super Air Nozzles, and the Back Blow style for cleaning out tubes, pipes, channels or holes from 1/4″ to 16″ in diameter.
EXAIR Air Jets utilize the Coanda effect (wall attachment of a high velocity fluid) to produce air motion in their surroundings. A small amount of compressed air (1) is throttled through an internal ring nozzle above sonic velocity. A vacuum is produced, pulling in large volumes of surrounding, or ‘free’ air, through an around the jet (2). The exit flow is the combination of the two air sources (3).
EXAIR manufactures Air Jets in two types, High Velocity, and Adjustable with materials of construction of brass and Type 303 Stainless Steel. The High Velocity Air Jet uses a changeable shim to set the gap, controlling the force and flow of the air. The Adjustable does not use a shim, and has a micrometer gap indicator and locking ring to allow for varying force and flow performance.
If you have questions about Air Nozzles and Jets, or would like to talk about any EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.