Among EXAIR’s comprehensive line of Intelligent Compressed Air Products, the Vortex Tube stands out as a unique, and fascinating, solution for a variety of applications requiring a flow of cold air: Cabinet Cooler Systems: clean,… More
One of the easiest ways to find out if your compressed air guns are safe for operation is by looking at the nozzle. First, take your current compressed air gun and disconnect it from the compressed air line. Second, look directly into the end of the nozzle where the air comes out. If you can see the inside of the nozzle, then your air gun or blow-off device is unsafe. Nine out of ten compressed air guns are considered to be dangerous. In this blog, I will go through the dangers and violations of compressed air guns and nozzles that are very common in the market place.
Occupational Safety and Health Administration, OSHA, is an organization that enforces standards for safe and healthy working environments. They have training, outreach programs, and educational assistance for manufacturing plant. But, they will also enforce these standards with heavy fines for violations. The two most common violations with compressed air guns and nozzles are 29CFR 1910.242(b) for dead-end pressure/chip shielding and 29CFR 1910.65(a) for maximum allowable noise exposure. If you are unfortunate in receiving an audit, the OSHA agent will target your compressed air guns and blow-off devices.
Here is the first example of a nozzle that I would like to discuss. As you can see, there is only one opening where the air can come out from the nozzle. Other types of nozzles that would fall into this category will include copper pipes, extensions, or worn nozzles. They are dangerous as the compressed air cannot escape if it is blocked by your skin. An air embolism could occur within the body which can cause bodily harm or death. If operated above 30 PSIG (2 bar), these nozzles would violate the OSHA 29CFR 1910.242(b) for dead-end pressure. This is a hazard which can be avoided by using EXAIR Super Air Nozzles and Safety Air Guns. The nozzles are designed to utilize fins to allow air to escape and not penetrate your skin. With EXAIR products, you will not violate this standard even if you go above the 30 PSIG (2 bar).
To counteract the dead-end pressure violation, some nozzle manufacturers created a hole through the side of the nozzle (Reference photo below). This will allow for the compressed air to escape, but, now the issue is noise level. With an “open” section in the nozzle, the compressed air is very turbulent and very loud. They state that 70% to 80% of all hearing loss within a manufacturing plant is caused by compressed air. For this, OSHA 29CFR 1910.65(a) was created to show the maximum allowable noise exposure. This chart shows the time and noise limits before requiring hearing protection. The EXAIR Super Air Nozzles are designed to have laminar flow which is very quiet. With our typical Safety Air Gun, model 1210, the sound level is only 74 dBA; well under the noise exposure limit for 8 hours.
Why do I bring these points up? Because safety is everyone’s responsibility. The National Institute for Occupational Safety and Health, NIOSH, has an overview of how to handle hazards in the workplace. They call it the Hierarchy of Controls (click). This is a means to best protect workers from dangers. The most effective way is by eliminating the hazard or substituting the hazard. The least effective way is with Personal Protective Equipment, or PPE. For your unsafe compressed air nozzles and guns, EXAIR can help by substituting the hazardous air gun and nozzle with an engineered solution designed with safety in mind.
In my opening statement, I explained a quick and easy method to determine if your compressed air guns are dangerous. To keep your company compliant and safe, EXAIR offers a variety of different types of nozzles and Safety Air Guns to best fit your requirement. If you find that you are using hazardous blowing equipment, you can contact an Application Engineer to find a safe and effective alternative.
The electrical costs associated with generating compressed air make it the most expensive utility in any industrial facility. In order to help offset these costs, it’s imperative that the system is operating as efficiently as possible. I’d like to take a moment to walk you through some of the ways that you can work towards making your compressed air system more efficient.
The first step you should take is to identify and fix any leaks within the distribution piping. According to the Compressed Air Challenge, up to 30% of all compressed air generated is lost through leaks. This ends up accounting for nearly 10% of your overall energy costs!! To put leaks in perspective, take a look at the graphic below from the Best Practices for Compressed Air Systems handbook.
Compressed air leaks don’t just waste energy, but they can also contribute to other operating losses. If enough air is lost through leaks, this can also cause a drop in system pressure. This can affect the functionality of other compressed air operated equipment and processes. This pressure drop can affect the efficiency of the equipment causing it to cycle on/off more frequently or to not work properly. This can lead to anything from rejected products to increased running time. With an increase in running time, there’s also the need for more frequent maintenance and unscheduled downtime.
You can perform a compressed air audit in your facility using an EXAIR Model 9061 Ultrasonic Leak Detector. If you’d prefer someone come in and do this for you, there are several companies that offer energy audit services where this will be a focal point of the process.
Speaking of maintenance, proper compressor maintenance is also critical to the overall efficiency of the system. Like all industrial equipment, a proper maintenance schedule is required in order to ensure things are operating at peak efficiency. Inadequate compressor maintenance can have a significant impact on energy consumption via lower compressor efficiency. A regular preventative maintenance schedule is required in order to keep things in good shape. The compressor, heat exchanger surfaces, lubricant, lubricant filter, air inlet filter, and dryer all need to be maintained. This can be done yourself or through a reputable compressor dealer. The costs associated with these services are outweighed in the improved reliability and performance of the compressor. A well-maintained system will not cause unexpected shutdowns and will also cost less to operate.
The manner in which you use your compressed air at the point of use should also be evaluated. Inefficient, homemade solutions are thought to be a cheap and quick solution. Unfortunately, the costs to supply these inefficient solutions with compressed air can quickly outweigh the costs of an engineered solution. An engineered compressed air nozzle such as EXAIR’s line of Super Air Nozzles are designed to utilize the coanda effect. Free, ambient air from the environment is entrained into the airflow along with the supplied compressed air. This maximizes the force and flow of the nozzle while keeping compressed air usage to a minimum.
Another method of making your compressed air system more efficient is actually quite simple: regulating the supply pressure. By installing pressure regulators at the point of use for each of your various point of use devices, you can reduce the consumption simply by reducing the pressure. This can’t be done for everything, but I’d be willing to bet that several tasks could be accomplished with the same level of efficiency at a reduced pressure. Most shop air runs at around 80-90 psig, but for general blowoff applications you can often get by operating at a lower pressure. Another simple, but often overlooked, method is to simply shut off the compressed air supply when not in use. If you haven’t yet performed an audit to identify compressed air leaks this is even more of a no-brainer. When operators go to lunch or during breaks, what’s stopping you from just simply turning a valve to shut off the supply of air? It seems simple and minute, but each step goes a long way towards reducing your overall air consumption and ultimately your energy costs.
Image taken from the Best Practices for Compressed Air Systems Handbook, 2nd Edition
Think about it…compressed air is, by definition, gas under pressure: potential (stored) energy. This energy is intended to do work, like operation of pneumatic tools, actuation of pneumatic cylinders, debris removal with an air gun or blow off device, and (even though I haven’t done it in a while) my personal favorite:
High pressure compressed air is meticulously made, prepared, and stored to ensure the number of surfaces equals the number of dives.
Uncontrolled, unplanned, or accidental releases of stored energy (regardless of the source) are inherently dangerous, and great care must be taken to guard against such incidents. This is accomplished, primarily, in three areas:
*Operation. This might be the most prevalent, because it involves the greatest number of personnel (e.g., everyone) as well as the ways compressed air is used (e.g., all of them.) It’s also the area where the most involved people (the operators) have the most control:
- Personal protection. Don’t even think about operating a compressed air device without eye protection. Ever. Hard stop. Also, if the operation involves flying debris, a full face shield, long sleeves, gloves, etc. might be called for. Hearing protection may be required as well…keep in mind, even if an engineered device (like any of EXAIR’s Intelligent Compressed Air Products) generates a relatively low sound level, the impingement noise of the air flow hitting the object can reach dangerous levels.
- Personnel cleaning is prohibited. The risk of injury to the eyes, respiratory system, and other parts is just too great to rely on personal protective equipment that’s designed for use while discharging compressed air AWAY from the body. While this is expressly prohibited in certain situations, OSHA has long recognized it as good practice for all industries.
- No horseplay. ’nuff said. Plenty of better ways to have fun at work.
*Design. This one usually has the advantage of being traceable to a small number of people, and is also the one that’s most likely to be documented. This is where it starts…if the system is designed to fail, it doesn’t matter how much care the operators take:
- Supply lines, fittings, and hoses must be rated for use with compressed air, up to and exceeding the maximum discharge pressure of the air compressor.
- This goes for any tools, blow off devices, components, etc., serviced by the air system. The only thing worse than a component failing is a component failing in your hand.
- Shut off valves should be located as close as practical to point(s) of operation. This allows you to quickly secure the flow of compressed air to a failed component, hose, etc., and prevent further damage or risk of injury.
- Hoses shouldn’t be run across the floor, where they can become a trip hazard or subject to damage from stepping on them. This is a surefire way to find out the value of shut off valves (see above.)
*Product specification. Or, more simply put, using the right tool for the job. A broader discussion could include efficiency and performance, but we’ll stay within the confines of safety for the purposes of this blog:
- Be mindful of dead end pressure. Blow off devices, especially hand held ones like air guns, are oftentimes fitted with a simple open-end discharge. If this is pushed into a part of the body, the pressurized air can break the skin and cause an air embolism. This is a serious injury, and can be fatal if it reaches the heart, lungs, or brain.
- This is a key consideration to OSHA Standard 1910.242(b), which limits the downstream pressure when compressed air is used for cleaning to 30psi.
- EXAIR products are compliant with this Standard by design…there’s always a relief path for the air pressure; they can’t be dead ended.
- Harmful sound levels are a consideration as well. As stated above, hearing protection is required in many cases, but sound levels can be mitigated through the use of engineered products. EXAIR Intelligent Compressed Air Products, as a result of their high entrainment, generate a boundary layer of air flow that leads to dramatically lower sound levels than a similar-sized open end blow off device.
If you’d like to explore ways to make your compressed air system safer, give me a call.
Upon moving to our new house, quite a distance from our old location, my wife and I were looking for a new “go to” restaurant that would be close to our new digs.
I did a Google search and found a place that was only a couple miles away and had good reviews. My wife and I went in and it was a quaint little place. The food was good, as expected, but the service was not.
We discussed the lackluster service and decided to go again about a week later hoping it was an isolated incident. On this visit we had a different server (which turned out to be the owner). Long story short, the service was again not good. It took a long time to place our order and receive our food.
I was ready to just write them off but my wife has a very soft and forgiving heart. So against my vote we go a third time. Which turned out to be a carbon copy of the 1st visit. With one great exception, we left after we had been there 25 minutes and our order was not taken. So, now we drive farther to our “old standby” because the service makes the difference to us.
The chart below is representative of reasons business’s lose customers.
Fortunately, EXAIR is a customer centric organization. EXAIR ensures that the staffing is present to handle your needs with the care and quickness you deserve and our culture dictates that we serve you effectively and efficiently! With both a Customer Service and Application Engineering Department we can handle your questions and requests consistently and accurately. Speak with a real person, and learn from over 159 years worth of combined manufacturing experience.
Did you know that most items are available for same day shipping (limits on quantities) with orders that can be processed by 3:00PM Eastern Time for the USA? Last but certainly not least EXAIR offer’s a 30 day money back guarantee on all our catalog items within 30 days of the purchase date!
When you are looking for quiet and efficient point of use compressed air products or static reduction devices, give us a call. Experience the EXAIR difference first hand and receive the great customer service, products and attention you deserve! We would enjoy hearing from you.
The below video reviews the Sanitary Flange Line Vac, the newest type from the EXAIR family of Line Vacs.
If you have questions about the Sanitary Line Vac, or would like to talk about any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.
EXAIR has wrote many different articles about how Vortex Tubes work and the applications in which they are used. The idea of making cold air without any freon or moving parts is a phenomenon. This phenomenon can generate cold air to a temperature as low as -50 oF (-46 oC). In this article, I will explain the adjustment of the Vortex Tube to get different temperatures and cooling effects in reference to the Cold Fraction.
To give a basic background on the EXAIR Vortex Tubes, we manufacture three different sizes; small, medium, and large. These sizes can produce a range of cooling capacities from 135 BTU/hr to 10,200 BTU/hr. The unique design utilizes a generator inside each Vortex Tube. The generator controls the amount of compressed air that can enter into the Vortex Tube. As an example, a medium-sized Vortex Tube, model 3240, will only allow 40 SCFM (1,133 SLPM) of compressed air to travel into the Vortex Tube at 100 PSIG (6.9 bar). While a small-sized Vortex Tube, model 3208, will only allow 8 SCFM (227 SLPM) of compressed air at 100 PSIG (6.9 bar). EXAIR manufactures the most comprehensive range from 2 SCFM (57 SLPM) to 150 SCFM (4,248 SLPM).
After the compressed air goes through the generator, the pressure will drop to slightly above atmospheric pressure. (This is the “engine” of how the Vortex Tube works). The air will travel toward one end of the tube where there is an air control valve, or Hot Air Exhaust Valve. This valve can be adjusted to increase or decrease the amount of air that leaves the hot end. The remaining portion of the air is redirected toward the opposite end of the Vortex Tube, called the cold end. By conservation of mass, the hot and cold air flows will have to equal the inlet flow as shown in Equation 1:
Equation 1: Q = Qc + Qh
Q – Vortex Inlet Flow (SCFM/SLPM)
Qc – Cold Air Flow (SCFM/SLPM)
Qh – Hot Air Flow (SCFM/SLPM)
Cold Fraction is the percentage of air that flows out the cold end of a Vortex Tube. As an example, if the control valve of the Vortex Tube is adjusted to allow only 20% of the air flow to escape from the hot end, then 80% of the air flow has to be redirected toward the cold end. EXAIR uses this ratio as the Cold Fraction; reference Equation 2:
Equation 2: CF = Qc/Q * 100
CF = Cold Fraction (%)
Qc – Cold Air Flow (SCFM/SLPM)
Q – Vortex Flow (SCFM/SLPM)
EXAIR created a chart to show the temperature drop and rise, relative to the incoming compressed air temperature. Across the top of the chart, we have the Cold Fraction and along the side, we have the inlet air pressure. As you can see, the temperature changes as the Cold Fraction and inlet air pressure changes. As the percentage of the Cold Fraction becomes smaller, the cold air flow becomes colder, but also the air flow becomes less. You may notice that this chart is independent of the Vortex Tube size. So, no matter the generator size of the Vortex Tube that is used, the temperature drop and rise will follow the chart above.
How do you use this chart? As an example, a model 3240 Vortex Tube is selected. It will use 40 SCFM of compressed air at 100 PSIG. We can determine the temperature and amount of air that will flow from the cold end and the hot end. The inlet pressure is selected at 100 PSIG, and the Hot Exhaust Valve is adjusted to allow for a 60% Cold Fraction. Let’s use an inlet compressed air temperature to be 68 oF. With Equation 2, we can rearrange the values to find Qc:
Qc = CF * Q
Qc = 0.60 * 40 SCFM = 24 SCFM of cold air flow
The temperature drop from the chart above is 86 oF. If we have 68 oF at the inlet, then the temperature is (68 oF – 86 oF) = -18 oF. So, from the cold end, we have 24 SCFM of air at a temperature of -18 oF. For the hot end, we can calculate the flow and temperature as well. From Equation 1,
Q = Qc + Qh or
Qh = Q – Qc
Qh = 40 SCFM – 24 SCFM = 16 SCFM
The temperature rise from the chart above is 119 oF. So, with the inlet temperature at 68 oF, we get (119 oF + 68 oF) = 187 oF. At the hot end, we have 16 SCFM of air at a temperature of 187 oF.
With the Cold Fraction and inlet air pressure, you can get specific temperatures for your application. For cooling and heating capacities, these values can be used to calculate the correct Vortex Tube size. If you need help in determining the proper Vortex Tube to best support your application, you can contact an Application Engineer at EXAIR. We will be glad to help.
Just recently I worked with our Distributor in Argentina on an application for a manufacturer of bottled water. Once the bottles are filled, a protective security seal is placed along the top of the bottle. This serves two purposes, it prevents any form of tampering as well as keeps the cap of the bottle clean throughout the rest of the manufacturing process. Since most people drink directly from the bottle, this area needs to remain clean and not be exposed to contamination later on in the process.
Their problem was that static was building up on this plastic which caused an improper seal on the cap of the bottle. Further down the processing line, the bottles can be exposed to water that contaminates the bottles. They had to implement an inspection process as it was not acceptable to allow any contaminated bottles to leave the plant. Without a solution, they were losing time due to the necessary inspection as bottles were being rejected at a rate of almost 30%.
The recommended solution was to install a Model 8164 4″ Gen4 Super Ion Air Wipe just prior to the point in the process where the seal was applied. The plastic material passed through the center of the Super Ion Air Wipe which neutralized the static charge on the material. Without a charge, the seal was applied correctly and they were able to eliminate the need of a manual inspection. After installation, the reject rate dropped to 0%!!
The Gen4 Super Ion Air Wipe provides a uniform 360° ionized airstream and is available in both 2” and 4” ID sizes. Its clam-shell design makes it easy to clamp around a part for neutralizing static electricity and contaminants. The high volume, high velocity airflow attaches itself to the surface and wipes it down with static eliminating ions. The airflow stays attached to the surface and is effective up to 15’ away from where it’s mounted. It’s lightweight and easy to mount using the ¼-20 tapped holes on the back or can also be held into place with just rigid pipe.
As the temperatures begin to decline, so does the humidity in the air. Drier air results in an increase in static problems. Get ahead of it this year and check out EXAIR’s wide line of various Static Elimination products, all available to ship same-day from stock!