In 1972, the US Department of Labor’s Occupation Safety & Health Administration (OSHA) established Standard 29 CFR 1910.242(b) to reduce the outlet pressure to less than 30 psi, of an open pipe, nozzle, air gun, etc. when being used for cleaning. The intent of this directive was to prevent injury to operators. They determined that 30 psi was the pressure in which the skin could be broken if the device were dead-ended against the operator’s body, causing an injury known as an air embolism…the dead-ended force of the air, under pressure, breaks the skin and introduces air flow inside the body. This is a VERY dangerous condition which can quickly lead to serious injury, possible stroke or ultimately death.
While OSHA doesn’t recommend any type or manufacturer of device, they do provide two methods you can follow to gain compliance.
The first would be to reduce the operating pressure below 30 PSI, as shown in the below line drawing. This, of course, limits the strength and usefulness of the exhausting air flow before it reaches the nozzle and before it is used upon the application.
The other method indicates using a nozzle which includes a pressure reducer or a relief device which will reduce the air pressure to less than 30 psi if the nozzle is dead ended. All of EXAIR‘s products are engineered to meet or exceed this Standard. In the case of our Super Air Nozzles, the air exits through a series of jets, recessed behind an array of fins, so the outlet holes cannot be blocked directly, any potential obstruction of the outlet air holes results in the air having an alternative route to avoid injury to operators and personnel. This allows the full pressure (the highest energy) to reach the nozzle and the application.
Open air lines and homemade blow offs violate OSHA standard 1910.242(b) because of harmful dead end pressures. If you would like to discuss how EXAIR products can help you gain OSHA compliance to increase personnel safety and avoid costly fines, please give me a call, I’d be happy to help.
Of the 3 styles of Air Knife offered by EXAIR, the Super, Standard and Full-Flow, the Super Air Knife is our most efficient, in regards to compressed air usage. Using a 40:1 amplification rate of entrained ambient air to compressed air consumed, it uses only 2.9 SCFM per inch of knife length when operated at 80 PSIG, while producing a low sound level of only 69 decibels (the quietest on the market today). The Super Air Knife provides an even laminar flow of air across the length of the knife and is available in single piece lengths from 3″ up to 108″ in aluminum, 303 stainless and 316 stainless as well as up to 54″ in PVDF (Polyvinylidene Flouride) construction for applications where aggressive chemicals may be present. 1/4″ FNPT air inlets are available on each end as well as on the bottom of the knife.
For Super Air Knives 24″ and longer, you need to plumb air to multiple inlets to maintain an even airflow. Our available Plumbing Kits includes the properly sized hose or pipe and fittings, to not only save valuable time looking for these parts yourself but also eliminates the potential of using undersized lines which will reduce the performance of the Super Air Knives.
For Super Air Knives in aluminum construction, the Plumbing Kits include cut to length PVC compressed air hose and the required brass fittings.
The Plumbing Kits for our stainless steel and PVDF Super Air Knives, include 316ss cut to length pipe as well as 316ss fittings.
The Super Air Knife is the ideal choice when looking to treat wide-area applications, like cleaning a conveyor or drying parts after a wash process. For help selecting the best product to fit your process, contact one of our application engineers for assistance.
I was recently contacted by a Chicken Farm in Canada about a blow off application for cleaning the dust and debris off the walls and ceilings in their barns. They currently use a 185 SCFM portable, engine driven compressor and a lance made from 3/4″ open copper tube. The barns are rather large, approximately 10′ high by 500′ long, and they place the compressor in the middle of the barn and have a 250′ length of hose going to the homemade blowoff. This setup worked fine for a minute or so but then the airflow would start to weaken at the point-of-use and the compressor would run continuously as it wasn’t able to maintain pressure to keep up with the demand of the copper pipe.
After discussing the details of the application, I recommend the customer use our Model # 1214-6 Super Blast Safety Air Gun with 6′ aluminum extension. This would reduce the air demand to 91 SCFM, more suitable for use with the existing 185 SCFM compressor.
The design of the Super Blast Safety Air Gun features a spring loaded manual valve, providing automatic shutoff and a comfortable foam grip. The 6′ extension provides the extra reach they need to effectively treat the walls and ceilings in the barn.
The Super Blast Safety Air Guns are ideal for wide coverage, long distance applications. They use our Large Super Air Nozzles and Super Air Nozzle Clusters, providing forces levels from 3.2 lbs. up to 23 lbs, depending on which nozzle is fitted on the assembly. Air inlets range from 3/8 FNPT up to 1-1/4 FNPT and aluminum extensions are available in 36″ or 72″ lengths.
If you have any questions or need further assistance, please contact an application engineer.
I was recently contacted by a plastics manufacturer who was needing some solutions for problem areas in their production processes. The company imports their machines from overseas and they are outfitted with a coolant based, quench system for the tooling. They were wanting to get away from using coolant as the parts were absorbing liquid, causing them to swell, not to mention the mess they were creating, requiring more time and labor to dry and clean the parts manually.
For the first application, replacing the messy misting system, I recommended the customer use our Cold Gun System, Model # 5215. The Cold Gun uses Vortex Tube technology to produce a cold air stream 50°F lower than the incoming compressed air supply temperature. For example, if your supply air was ambient 70°F, you would effectively see 20°F air at the exhaust. This clean, cold air stream can be easily directed to the needed area to prevent any warping or other damage related to heat, while also blowing away the machined fines.
The second part of the process involved the recovery of the plastic scrap and chips created during the machining process. Once again, EXAIR has the ideal solution with our Chip Vac, Industrial Vacuum. The Chip Vac creates a powerful vacuum, with no moving parts or motors to wear out, making them virtually maintenance free. The Chip Vac is designed to vacuum dry or wet chips and collect them in a standard, open-top steel drum. Systems are available in 5, 30, 55 or 110 gallon capacities.
To discuss how EXAIR products might help improve your machining process, give us a call at 800-903-9247.
If you follow along with our blog, you will notice that we have recently published a few entries relating to our Atomizing Nozzles. Today, I would like to continue this trend and focus on our Siphon Fed Atomizing Nozzles.
When recommending an Atomizing Nozzle for a particular process, we try to obtain as much “general” information as possible about the application, such as:
What type of spray pattern do you need?
How wide of an area needs to be covered?
What kind of flow rate needs to be achieved?
Is the liquid source pressurized?
What is the viscosity of the liquid?
While all of this information is going to help simplify the selection process, when we get a reply that the liquid isn’t pressurized, the choice becomes a little less complicated.
Our Siphon Fed Atomizing Nozzles are the preferred solution in applications where a pressurized liquid source isn’t available. With a steady supply of compressed air, these nozzles are able to draw the liquid into the nozzle with suction heights up to 36″ for our 1/8″ NPT and 1/4″ NPT nozzles, and up to 24″ for our larger 1/2″ NPT Models. They can also be gravity fed as well.
These nozzles mix the fluid internally and are capable of handling viscosity up to 200 centipoise. Depending on the size of the nozzle and supply air pressure, flow rates can range from 0.4 GPH up to 60 GPH with either a round or flat fan spray pattern. There is also an adjusting valve for more or less liquid flow as needed to fit the demand of the application.
We also offer these nozzles with our patented No Drip feature which positively stops the liquid flow when the supply air pressure drops below 30 PSIG, eliminating the need for any additional valves or supply lines.
If you have an application requiring a fine mist of atomized liquid, give me a call at 800-903-9247.
When air is compressed, it is heated to a point that causes the water or moisture to turn to vapor. As the air begins to cool, the vapors turn to condensation, which can cause performance issues in a compressed air system. Many times this condensation forms in the basic components in the system like a receiver tank, dryer or filter.
It’s important to remove this condensation from the system before it causes any issues. There are four basic types of condensate drains that can be used to limit or prevent loss of air in the system.
The first method would be to have an operator manually drain the condensation through a drain port or valve. This is the least reliable method though as now it’s the operator’s responsibility to make sure they close the valve so the system doesn’t allow any air to escape which can lead to pressure drops and poor end-use device performance.
Secondly, a float or inverted bucket trap system can be used in plants with regular monitoring and maintenance programs in place to ensure proper performance.. These types of drain traps typically require a higher level of maintenance and have the potential to lose air if not operating properly.
An electrically actuated drain valve can be used to automatically drain the condensate at a preset time or interval. Typically these incorporate a solenoid valve or motorized ball valve with some type of timing control. These types of systems can be unreliable though as the valve may open without any moisture being present in the line, which can result in air loss or it may not be actuated open long enough for acceptable drain off. With these types of drains, it’s best to use some type of strainer to remove any particulate that could cause adverse performance.
Lastly, zero air-loss traps utilize a reservoir and a float or level sensor to drain the condensate and maintain a satisfactory level. This type of setup is very reliable but does require the reservoir be drained frequently to keep the system clean and free of debris or contaminants.
If you have any questions or would like to discuss a particular process, contact an application engineer for assistance.
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.