Engineered Air Nozzles by EXAIR Replace Modular Coolant Hose & Save Thousands!!

A common item that can be found in a majority of machine shops is the blue or gray knuckle-jointed hose used to dispense coolant on lathes and CNC machines. EXAIR also uses this same hose with our Cold Guns and Adjustable Spot Coolers for applications that cannot or do not wish to use liquid coolant as a means of keeping the heat down on their tooling. Since the cold air discharges at atmospheric pressure, this is an acceptable application.

Another application is using this style of hose as a compressed air blowoff. This is NOT a proper use of the hose and is not only a considerable waste of compressed air but can also pose a safety hazard. Using this method for compressed air blowoff is not compliant with OSHA 1910.242(b).

I was recently contacted by a customer in Indonesia that was using an array of (6) of these knuckle-jointed hoses with a ¼” round nozzle attachment for a blowoff operation. The customer had a series of rubber pads used in the construction of a toy castle. The pads were brought along by an overhead conveyor and a design was printed on the head of the pad.

The nozzles were used to dry the ink before the pad made it to the next part of the process. This was a new product line and the processes involved were being evaluated for potential places to save on compressed air rather than adding overall capacity to their system. After using a variety of EXAIR products for other blowoff applications, they came back for another engineered solution.

HP1126-9280 unassembled

After testing both a 1009-9280 (Adjustable Air Nozzle w/ 30” Stay Set Hose) and an HP1126-9280 (1” High Power Flat Nozzle w/ 30” Stay Set Hose), the customer determined that the airflow pattern from the 1” Flat Nozzle was more conducive to drying the rubber pad and purchased the remaining units to replace their original method. The compressed air savings was noticed immediately!!

For the old operation, they had to regulate the pressure down on the hose to 25 psig so that the hose wouldn’t break apart. (1) This hose , with a ¼” round nozzle, will consume 52 scfm at 25 psig of supply pressure. With (6) of these they were consuming a whopping 312 scfm!! Since the HP1126 is compliant with OSHA directive 1910.242(b) and will not break apart at higher pressures, they were able to operate at 80 psig while only consuming 17.5 scfm. They saved more than enough air for their new process and are evaluating whether or not they can turn off one of their smaller 25 HP compressors.

The new setup with the EXAIR engineered solution was able to save them 207 scfm of compressed air. Assuming a cost of $.25/1000 scfm and a 40 hr work week, this translates to an overall savings of $6,458.40 per year off of their utility bill.

207 scfm x 60 minutes x 8 hrs/day x 5 shifts/week x 52 weeks/year =25,833,600 scf

25,833,600 scf x ($.25/1000 scf) = $6,458.40

If you’re using an inefficient compressed air blowoff in your facility, give us a call. An Application Engineer will be happy to evaluate your process and determine the safest and most efficient solution. With same day shipment for stock items on orders placed by 2:00 pm ET, we can get a solution out to you fast. And you can be saving money upon installation!

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@exair.com
Twitter: @EXAIR_TD

Considerations for Ejecting Parts with an Air Nozzle: Weight and Friction

I had a customer wanting to reject a container off a conveyor belt.  The container held yogurt, and when an optic detected a reject, they wanted to operate a solenoid to have a nozzle blow the container into a reject bin.  They had a range that went from 4 oz. (113 grams) for the small containers to 27 oz (766 grams) for the large.  He wanted me to suggest one nozzle for all sizes, as they would automatically regulate the pressure for the full range of products.  In looking at the largest size, this container will need the most force to blow off the conveyor.  The two factors that affects the force in this type of application is weight and friction.  When it comes to friction, it is generally an unknown for customers.  So, I was able to help with a couple of things to determine the friction force.

Friction is a dimensionless number that represents the resistance created between two surfaces.  We have two types; static friction, ms, and kinetic friction, mk.  Static friction is the maximum amount of resistance before the object begins to move or slide.  Kinetic friction is the amount of resistance that is created when the object is moving or sliding.  So, Static friction is always greater than kinetic friction, ms > mk.  For this application, we will use an air nozzle to “shoot” horizontally to hit the rejected product.

Let’s take look at our customer’s application.  We have a system to reject a non-conforming part with air.  The conveyor has a urethane belt.  The container is plastic.  For the largest container, they have a weight of 27 oz. (766 grams).  Being that the conveyor belt is only 12” (30.5 cm) wide, we can determine that if we get the part moving, it will continue off the belt and into the reject bin.  The equation for the maximum amount of force required to move a container is below as Equation 1.

Equation 1

Fs = ms * W

Fs – Static Force in ounces (grams)

m– Static Friction

W – Weight in ounces (grams)

One way to determine the amount of force is to use a scale similar to a fish scale.  The scale should have a maximum indicator to help capture the maximum amount of force.  You will have to place the object on the same belt material because different types of materials will create different static forces. Keep the scale perpendicular to the object, and slowly pull on the scale.  Once the part begins to move, record the scale reading.  For the exercise above, it showed 9.6 oz. (271 grams) of force to move the 27 oz. (766 gram) object.

Another way would be to calculate the static friction, ms.  Static friction can be found by the angle at which an object starts to move.  By placing the container on a section of supported urethane conveyor belt, you can lift one end until the object starts to slide.  The height of the lift can be measured as an angle.  As an example, we take 3 feet (0.9 meter) of supported urethane conveyor belt, and we lifted one end to a height of 1 foot (0.3 meters) before the 27 oz (766 gram) container moved.  To determine static friction, it is the tangent of that angle that you lifted.  With some right triangle trigonometry equations, we get an angle of 19.5o.  Thus, ms = tanq or ms = tan(19.5o) = 0.354.  If we plug this into Equation 1, we get the following:

Imperial Units                                                    SI Units

Fs = ms * W                                                         Fs = ms * W

= 0.354 * 27 oz.                                                = 0.354 * 766 grams

= 9.6 oz. of force                                              = 271 grams of force

1″ Flat Super Air Nozzles

Now that we have the static force, we want to be slightly higher than that.  In looking at the force requirements that are published in the EXAIR catalog, it shows that the model 1126 1” Super Flat Air Nozzle has a 9.8 oz. (278 grams) of force at 80 PSIG (5.5 Bar).  This force is measured at a 12” (30.5 cm) distance with a patented .015” (0.38mm) shim.  So, this nozzle will be able to slide the largest container into the reject bin.

1″ Flat Super Air Nozzle shims

To expand on the benefits in using the EXAIR Flat Super Air Nozzles, the force can be changed easily with a regulator or with a Shim Set.  This is a unique feature as most competitive flat nozzles do not allow you to do this.  The patented shims control the force rating in a wide range with lower air consumption and lower noise levels; making them safe and efficient.  So, if this manufacturer decided to produce other sizes in the future, then they could change the shim to target even larger containers.  The flexibility of using the EXAIR Flat Super Air Nozzles allow you to increase or decrease the force by just removing two screws and changing the thickness of the shim inside.  EXAIR does offer a pack of shims with different thicknesses which are called a Shim Set.

With air pressure or shim manipulation, the customer could use the same nozzle for the yogurt containers.  If you have any applications that need products to be rejected quickly, an Application Engineers at EXAIR will be happy to help you with a solution.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Photo: Yogurt by BUMIPUTRAPixabay Licence

What is Laminar Flow and Turbulent Flow?

Super Air Knife

Fluid mechanics is the field that studies the properties of fluids in various states.  There are two areas, fluid statics and fluid dynamics.  Fluid dynamics studies the forces on a fluid, either as a liquid or a gas, during motion.  Osborne Reynolds, an Irish innovator, popularized this dynamic with a dimensionless number, Re. This number determines the state in which the fluid is moving; either laminar flow or turbulent flow.  Equation 1 shows the relationship between the inertial forces of the fluid as compared to the viscous forces.

Equation 1:  Re = V * Dh/u

Re – Reynolds Number (no dimensions)

V – Velocity (feet/sec or meters/sec)

Dh – hydraulic diameter (feet or meters)

u – Kinematic Viscosity (feet^2/sec or meter^2/sec)

The value of Re will mark the region in which the fluid (liquid or gas) is moving.  If the Reynolds number, Re, is below 2300, then it is considered to be laminar (streamline and predictable).  If Re is greater than 4000, then it is considered to be turbulent (chaotic and violent).  The area between these two numbers is the transitional area where you can have eddy currents and some non-linear velocities.  To better show the differences between each state, I have a picture below that shows water flowing from a drain pipe into a channel.  The water is loud and disorderly; traveling in different directions, even upstream.  With the high velocity of water coming out of the drain pipe, the inertial forces are greater than the viscosity of the water.  This indicates turbulent flow with a Reynolds number larger than 4000.  As the water flows into the mouth of the river after the channel, the waves transform from a disorderly mess into a more uniform stream.  This is the transitional region.  A bit further downstream, the stream becomes calm and quiet, flowing in the same direction.  This is laminar flow.  Air is also a fluid, and it will behave in a similar way depending on the Reynolds number.

Turbulent to Laminar Water

Why is this important to know?  In certain applications, one state may be better suited than the other.  For mixing, suspension and heat transfer; turbulent flows are better.  But, when it comes to effective blowing, lower pressure drops and reduced noise levels; laminar flows are better.  In many compressed air applications, the laminar region is the best method to generate a strong force efficiently and quietly.  EXAIR offers a large line of products, including the Super Air Knives and Super Air Nozzles that utilizes that laminar flow for compressed air applications.  If you would like to discuss further how laminar flows could benefit your process, an EXAIR Application Engineer will be happy to help you.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Nozzles for Cleaning Inside Hose, Tube, Pipe and More

Some applications such as blowing chips or debris out of a pipe or blind hole, it may not be possible to blow forward. The pipe may be too long, making it impossible to push the debris all the way down the pipe or the other end of the pipe may not be open. In either of these scenarios, the Back Blow Nozzle is the right tool for the job. An array of holes around the diameter of the Back Blow Nozzles provides a powerful 360° airflow pattern that will clear out any leftover coolant or chips from the machining process.

EXAIR has three different size Back Blow Nozzles; the 1004SS (M4 x .5), the 1006SS (1/4 NPT), and the 1008SS (1” NPT). The 1004SS is recommended for use on pipes as small as ¼” and up to 1”. The 1006SS can be used for a wide range of pipe sizes, from 7/8” up to 4”. The 1008SS nozzle offers the greatest overall force for stubborn or sticky materials stuck to the inside diameter of the pipe. This nozzle is suitable for use in pipes ranging from 2”-16”. As the Back Blow Nozzle will be blowing chips and debris back out of the pipe towards the operator, it is always recommended that a Chip Shield is used. The strong polycarbonate Chip Shield will keep them safe from flying debris and keep you in compliance with OSHA directive 1910.242(b).

Various Views of the Model 1006SS Back Blow Nozzle

All of EXAIR’s Back Blow Nozzles are available with extensions. For the 1004SS we have extensions from 6”-36”, and from 12”-72” for the 1006SS and 1008SS. The Back Blow Nozzle can also be installed on our VariBlast, Soft Grip, Heavy Duty, and Super Blast Safety Air Guns. With such a wide range of available sizes and configurations, we can tackle just about any internal pipe cleaning application. If you have a process in your facility that may benefit from the use of one of these nozzles, give us a call and get one on order today!

Jordan Shouse
Application Engineer

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