Rotational molding: EXAIR Super Air Amplifiers compared to fans

 A customer contacted EXAIR to find a better way to cool a die in a rotational molding facility.  Rotational molding, or Rotomolding, involves a heated hollow mold which is filled with plastic material. It is then slowly rotated (usually around two perpendicular axes), causing the softened material to disperse and cling to the walls of the mold. In order to maintain an even thickness throughout the part, the mold has to continue to rotate during the heating phase. After the desired timing sequence, the heating is turned off to allow the material to harden. 

This particular company was making plastic containers.  To try and improve the cycle rate between each container, they were using two fans (reference photo below) for cooling.  Time is money in this industry, and they wanted to target the fans to improve cooling.  They mentioned that water jackets for cooling would affect the life of the molds due to thermal shock.  So, they needed to cool with air; and EXAIR had a solution for them; the Super Air Amplifiers.

The Super Air Amplifiers as compared to fans are compact, easy to use, and very effective in cooling.  The capacity to cool is determined by the mass of air and the temperature difference. Since the mold is heated to 650oF (343oC) and the ambient air is 80oF (27oC), we have a good temperature difference for cooling.  For this application, I recommended to replace their fans with our model 120024 4” Super Air Amplifiers.  Each one can move 2,190 SCFM (6,1977 SLPM) of air while only needing 29.2 SCFM (826 SLPM) of compressed air at 80 PSIG (5.5 Bar). 

I also recommended to add one piece of a model 120022 2” Super Air Amplifier for cooling the inside of the mold.  Because the opening in the center of the mold is relatively small, a fan would take up most of the area.  Thus, not allowing the hot air to escape.  Since the 2” Super Air Amplifier is much smaller, they were able to place the air stream in the center allowing the hot air to escape around the edge of the hole.  With this combination, we were able to cool the mold 25% faster than the fans.    

To expand on the comparison, EXAIR Super Air Amplifiers and electrical fans are designed to move air.  Fans use motors and blades to push the air toward the target.  There are mainly two types, centrifugal fans and axial fans.  The customer above was using axial fans.  The air enters from directly behind the fan, and the blades “slap” the air forward to the target. This creates a turbulent and loud air noise.  The EXAIR Super Air Amplifiers does not use any blades or motors to push the air.  They use a Coanda profile with a patented shim to create a low pressure to draw the air.So, they create laminar air flow which is much quieter.

In physics, it is easier to pull than it is to push.  The same goes for moving air.  Fans are designed to “push” the air and the Super Air Amplifiers are designed to “pull” the air.  This method of pulling makes it simple to create a laminar flow in a small package which is more efficient, effective, and quiet.  With the patented shims inside the Super Air Amplifiers, they maximize the amplification by “pulling” in large amounts of ambient air while using less compressed air.  More air means better cooling.  If you want to move away from blower systems or axial fan systems to get better cooling, drying, cleaning, and conveying; you can contact an Application Engineer for more details about our Super Air Amplifiers. 

	Vivek Engineers #22, 1st Floor, 1st Cross, Adj. to IIMB Compound, Bilekahalli Indl. Area,  Bannerghatta Road, Bangalore - 560 076  Ph : 080 -  2648 1309, 4170 1145. Mob : 097404 39220
	Email: sales@vivekengineers.net ,          durga@vivekengineers.net

EXAIR’s Deep Hole Vac-U-Gun

 The Deep Hole Vac-u-Gun is a special iteration of the Vac-u-Gun, designed to provide a solution to the troublesome process of cleaning cavities and drilled holes.

The Deep Hole Vac-u-Gun is a low cost solution to quickly remove chips and debris from grooves and drilled holes where blow gun could create potentially hazardous flying debris. The Deep Hole Vac-u-Gun is simply positioned over the hole, and the trigger squeezed and then a small blow tube delivers a a stream of air to dislodge and lift the chips while the large suction tube vacuum them away. The operator is protected form flying debris since all chips and debris is contained within the clear suction tube. The device is capable of cleaning holes up to 1-1/4″ (32mm) diameter and 18″ (457mm) deep!
How does the Deep Hole Vac-u-Gun work?

Compressed air, normally 80-100 PSIG (5.5 – 6.9 bar), flows through the inlet (1) into an annular plenum chamber (2) when the trigger is pressed. A small amount of air is injected into the blow tube (3) to provide agitation and lift to the chips or debris. The larger airflow is injected into the the throat of the gun through directed nozzles (4). The jets of air create the vacuum at the intake (5) which draws the material in and accelerates it through the unit. The chips, debris or other particulates can then be exhausted into a filter bag or hose attached to the Deep Hole Vac-u-Gun System.

We have found many applications where the Deep Hole Vac-u-Gun is beneficial- including removing chips and debris in:

Holes in fixtures, drilled plastics, T-slot groove cleaning , coolant evacuation from parts, woodworking, tapped holes, cavity evacuation, and many more!

There are many advantages to the Deep Hole Vac-u-Gun, and some are:

Low cost, no moving parts/maintenance free, durable die cast construction, eliminates shock hazard – no electricity, meets OSHA pressure requirements, safe operation – no flying chips, lightweight and portable, and quiet.

The Deep Hole Vac-u-Gun uses less compressed air than ordinary blow guns, and the amplified output flow is 12 times the air consumption rate.

Note that the Deep Hole Vac-u-Gun should not be operated without a filter bag or vacuum hose attached to the exhaust.

There are three (3) Deep Hole Vac-u-Gun System options-

The Model 6094 is the Deep Hole Vac-u-Gun only.

The Model 6194 comes with a reusable bag and clamp for debris collection.

The Model 6394 comes with the reusable bag and a 10′ (3m) section of vacuum hose for transferring the debris to a collection point.

If you have questions about the Deep Hole Vac-u-Gun or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact us.

	Vivek Engineers #22, 1st Floor, 1st Cross, Adj. to IIMB Compound, Bilekahalli Indl. Area,  Bannerghatta Road, Bangalore - 560 076  Ph : 080 -  2648 1309, 4170 1145. Mob : 097404 39220
	Email: sales@vivekengineers.net ,          durga@vivekengineers.net

Installing the EXAIR Model 4908 Dual Cabinet Cooler Hardware Kit

 

	Vivek Engineers #22, 1st Floor, 1st Cross, Adj. to IIMB Compound, Bilekahalli Indl. Area,  Bannerghatta Road, Bangalore - 560 076  Ph : 080 -  2648 1309, 4170 1145. Mob : 097404 39220
	Email: sales@vivekengineers.net ,          durga@vivekengineers.net

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

Exair 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)

ms  – 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

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.

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.

	Vivek Engineers #22, 1st Floor, 1st Cross, Adj. to IIMB Compound, Bilekahalli Indl. Area,  Bannerghatta Road, Bangalore - 560 076  Ph : 080 -  2648 1309, 4170 1145. Mob : 097404 39220
	Email: sales@vivekengineers.net ,          durga@vivekengineers.net

Vortex Tubes: What, Why, Where?

 

The most common questions about Vortex Tubes are “How long have they been around?” and “How do they work?”. These questions are simple enough and answering someone how long Vortex Tubes have been around is the easy answer, Vortex Tubes have been around since 1928 with what may seem as an accidental existence by the developer George Ranque.

As to how they work, these are a phenomenon of physics and the theoretical math behind them has yet to be proven and set in stone. They have been called various names such as “Maxwell’s Demon” which posited that a demon was splitting the hot and cold air molecules prior to leaving the Vortex Tube.  They have also been referred to as  the “Ranque Vortex Tube”, “Hilsch Tube”, and the “Ranque-Hilsch Tube” which highlight some of the prominent people in developing vortex tubes. 

WHAT: EXAIR defines a Vortex Tube within our catalog as “a low cost, reliable, maintenance free solution to a variety of industrial spot cooling problems. Using an ordinary supply of compressed air as a power source, vortex tubes create two streams of air, one hot and one cold, with no moving parts.”

The scope of Vortex Tubes include being able to produce temperatures from -50 degrees to 260 degrees Fahrenheit with flow rates from 1 to 150 SCFM and refrigeration up to 10,200 Btu/hr. Temperatures, flows and cooling power can be easily adjusted with the control valve located on the “hot” end of the tube.

WHY: EXAIRs’ Vortex Tubes offer low cost and reliable solutions primarily for product cooling and sometimes heating. Constructed of stainless steel, our vortex tubes are resistant to corrosion and oxidation providing for years of reliable maintenance-free operation. Vortex tubes operate with a source of compressed air with no moving parts or electricity.

EXAIR offers two series of vortex tubes. The 32XX series is “Maximum Refrigeration (cooling) and is typically used for process cooling, part cooling or chamber cooling. The 34XX series provide lowest cold temperatures at low cold airflow and typically used in cooling lab samples and circuit testing.

EXAIR offers a cooling kit with interchangeable generators that are easily changed so you can experiment and find what temperature and airflow works best for your application.

WHERE: There are many uses for EXAIR Vortex Tubes including but not limited to cooling electronics, machining operations, CCTV cameras, soldered parts, gas samples, heat seals, environmental chambers, ultrasonic weld horns, welds and setting hot melts.

The history of EXAIR Vortex Tubes and the variety of uses has derived new products designed for specific applications like our Spot Coolers and Cabinet Coolers. These items can be found in our catalog or at www.vivekengineers.net

	Vivek Engineers #22, 1st Floor, 1st Cross, Adj. to IIMB Compound, Bilekahalli Indl. Area,  Bannerghatta Road, Bangalore - 560 076  Ph : 080 -  2648 1309, 4170 1145. Mob : 097404 39220
	Email: sales@vivekengineers.net ,          durga@vivekengineers.net

What Is The Gen4® Ion Air Gun?

 EXAIR's Gen4 Ion Air Gun combines incredibly fast static decay rates with low compressed air consumption. It is the ideal way to remove static, contaminants and dust from three dimensional parts prior to assembly, packaging, painting or finishing. The Gen4 Ion Air Gun neutralizes static electricity and cleans at distances up to 15 feet (4.6m).

The Gen4 Ion Air Gun induces surrounding airflow through the gun at a ratio of 5:1, minimizing compressed air usage and maximizing ionized airflow. The force can be adjusted from a “blast” to a “breeze”. A comfortable grip and hand position allows hours of continuous use without fatigue.

The Gen4 Ion Air Gun is quiet, lightweight and features a hanger hook for easy storage. The 10 foot (3m) armored and electromagnetic shielded power cable is extremely flexible, designed for rugged industrial use.

<<CLICK HERE>> to visit our website

	Vivek Engineers #22, 1st Floor, 1st Cross, Adj. to IIMB Compound, Bilekahalli Indl. Area,  Bannerghatta Road, Bangalore - 560 076  Ph : 080 -  2648 1309, 4170 1145. Mob : 097404 39220
	Email: sales@vivekengineers.net ,          durga@vivekengineers.net