Basics of Entrainment

EXAIR Super Air Nozzle entrainment

EXAIR has many choices for compressed air savings. EXAIR specifically takes pride in engineering products that not only save compressed usage when comparing to your existing processes but also considers the entrainment of ambient air compounding the compressed savings. Entrainment? Well think of it like this; We love “free” perks when using our reward cards at stores, gas stations or restaurants. Although you are paying the initial cost of whatever you are buying its nice knowing there is a “free” reward. We know producing compressed air is expensive, so we like that we have entrained savings when using our products.

EXAIR Super Air Knives are a perfect example of getting a reward when paying for your compressed air. Super Air Knives will entrain up to 40:1 ambient “free” air, so essentially you gain 40 SCFM of ambient air for every 1 SCFM being used. The illustration below shows more about our Super Air Knife.

Bernoulli’s equation takes into account four main variables which are Pressure (P), Density (r), Velocity (v), and a height difference (z); along with a single constant for gravity. The relationship between the velocity squared and the pressure from the equation above.  Being that this relationship is a constant along the streamline; when the velocity increases; the pressure has to come down. Now we have to look at how fluids like to behave. Fluids within a system like to be at a constant pressure when at the same height and reach a state of equilibrium. This means that fluids will always flow towards a low pressure area, which means that if you create a constant low pressure area you can amplify the air stream. This is the same principle as to why airplanes can fly.

Bernoulli’s Equation

EXAIR used the Bernoulli Principle when designing our Air Amplifiers, Air Knives, Air Wipes, Air Nozzles/Jets, Safety Air Guns and Static Eliminating Products. We not only designed in safety into our products but also the reward of “free” air or entrained air. If you would like to take advantage of the effects of air entrainment to improve your application blowing and cooling needs, we would like to be your first stop. Please contact any of our qualified Application Engineers for help with your application today!

Eric Kuhnash
Application Engineer
E-mail: EricKuhnash@exair.com
Twitter: Twitter: @EXAIR_EK

Porous and Non-Porous E-vac Generators

Having an injection molding background I saw many uses for parts pickers using many different sizes from 90 – to 3000 ton injection molding machines and a vast amount of part sizes and shapes that varied from items as small as dinner plates to as big as municipal refuse containers. I dealt mainly with non-porous applications but EXAIR offers both porous and non-porous E-vacs to accommodate wide range of part sizes and weights.

EXAIR has High Vacuum Generators for Non-Porous Applications with high vacuum units up to 27″ Hg (91 kPa) with vacuum flows up to 15.8 SCFM (447 SLPM). The plastic products I was moving were all non-porous, meaning air or liquids would not permeate into the surface of my product. Other examples of non-porous material including plastic sub-straights include glass, steel sheet, ceramics, vinyl, sealed tiles and varnished wood.

Porous applications use a low vacuum generator. Low vacuum units up to 21″Hg (71kPa) with flows up to 18.5 SCFM (524 SLPM) are typically used for porous materials such as corrugate, wood, fabrics, cinder block, etc… The relatively lower level vacuum for porous materials prevents warping, marring, dimpling or disfiguring of the surface due to excessive vacuum. This style generates more vacuum flow to overcome porosity and leakage while maintaining control over the object being handled.

Referencing the previously mentioned refuse container application, I performed the weight and movement analysis and determined that four of our model 900754 vacuum cups and two of our model 810006M Non-porous E-vacs would have been more than adequate to unload and lift my 95 gallon refuse container lids from the injection molding machine and move them to the hot stamp center. I recall the vacuum cup system we had in place back then, would frequently drop out and lose control over the product. This was not only a real process headache, but also made for a legitimate safety issue as well.

EXAIR E-vacs actually have other interesting uses. They have been used in applications for bag and package opening, label placement, vacuum forming, leak testing and many other applications.

EXAIR also has accessories to round out vacuum cup systems including vacuum cups themselves, mufflers, check valves, vacuum tubing and fittings. We would have interest to discuss your application. If you have questions regarding which E-vac style and size is proper for your project please contact any of our Application Engineers to help you with selection and design of your system.

Eric Kuhnash
Application Engineer
E-mail: EricKuhnash@exair.com
Twitter: Twitter: @EXAIR_EK

EXAIR’s Safety Air Guns are the Ergonomic Answer

In addition to a variety of engineered Air Nozzles, you can customize your EXAIR Safety Air Gun with Chip Shields, Extensions, Stay Set Hoses, etc., to meet the particular needs of a specific application.

EXAIR has a nice selection of Safety Air Guns. The VariBlast Precision and Compact, Soft Grip, Heavy Duty and Super Blast Safety Air Guns are available with a variety of air nozzles, chip shields and pipe extensions. They are durable and comfortable and ergonomic to use.

These Safety Air Guns are designed with durability and comfort in mind while also ergonomically safe to use. Safe operation is assured along with low air consumption and noise levels.

EXAIR Engineered air nozzles are available in Type 316 stainless steel for superior corrosion resistance and mechanical wear, Type 303 stainless steel for corrosion resistance, PEEK thermoplastic for non-marring and chemical resistance or zinc/aluminum alloy for general purpose applications.

Flying Debris? – Chip Shields are durable polycarbonate shields that protect the operator from risk of flying debris often seen when blowing off chips from machined parts. They are also useful to prevent coolant from splashing back, creating a mess during drying processes.

The Chip Shields are available for EXAIR’s VariBlast, Soft Grip and Heavy Duty Safety Air Guns. The Chip Shield can be used on Safety Air Guns with or without an aluminum extension. They may be purchased as part of a new air gun system, or retrofitted as a Chip Shield Kit.  Consult an Application Engineer for selection assistance.

If you have a blow-off process where the air is to be directed at a distance away from the operator, or into a hard to reach location an extension is the solution. Available in lengths from 6″ (152mm) to 72″ (1829mm), with sizes as to meet most requirement can be found. To add an extension to an air gun, simply add -xx to the current part number..

EXAIR’s Stay Set Hoses are available from 6”-36” in lengths with ¼ NPT male threads on each end, or a ¼ NPT male on one end and 1/8 NPT female on the other. The Stay Set Hoses are rigid and allow you to maintain precise positioning of the blow off nozzle. The hoses have “memory” and will not creep or bend.

 If you need a 12′ coiled air hose, to use with your Safety Air Gun, we have them available and in stock. Available with 1/8 NPT, 1/4 NPT or 3/8 NPT male end swivel connections. Avoid tangled and messy air lines and keep things neat!

If you have ab application and need help deciding which EXAIR Safety Air Gun and/Nozzle you need. Please contact us and ask for any Application Engineer. We are always happy and eager to help.

Eric Kuhnash
Application Engineer
E-mail: EricKuhnash@exair.com
Twitter: Twitter: @EXAIR_EK

Liquid ONLY Atomizing Spray Nozzles: FullStream & HollowStream

New to EXAIR’s line of Atomizing Nozzles are the FullStream and HollowStream Liquid Only Atomizing Nozzles. This family of nozzles does not require any source of compressed air to operate, just a supply of pressurized liquid.

They produce droplets by spinning the liquid and breaking its surface tension through a precise orifice or by impacting the liquid onto the surface of the nozzle. Compared to EXAIR’s Air Atomizing Spray Nozzles, these nozzles generate more liquid volume and produce a coarser spray pattern. This higher liquid volume is beneficial for industrial applications including cleaning, cooling, rinsing, dust suppression, and washing. Constructed of Type 303 stainless steel, these durable and rugged nozzles are ideal for industrial applications. They’re available in three sizes: ¼ NPT, 3/8 NPT, and ½ NPT for the Fullstream and ¼ NPT & 3/8 NPT for the HollowStream. These nozzles can achieve flowrates ranging from 0.06 GPM and up to 17.64 GPM with the largest ½” NPT FullStream.

This style of nozzle is a good fit for general-purpose applications in industry and will commonly be used to spray inexpensive liquids such as water, rinse aids, or detergents. They’re also effective for spraying a variety of chemicals, pesticides, and herbicides.

Adjustments to the nozzle’s liquid flow rate can be achieved by regulating the liquid pressure supplied to the nozzles. As we increase the liquid pressure, the flow through the nozzle will increase. As the pressure increases, not only do we increase the overall liquid flow rate but also the size of the spray pattern. If tighter control of liquid flow rate is needed, EXAIR’s Air Atomizing Nozzles will provide such level of control over the application of fluids.

The FullStream Cone Nozzles produce a full cone spray pattern and are among the most common style of spray nozzle available on the market today. They produce a uniform distribution of liquid in a cone shaped round pattern. Their tangential flow is vaneless, creating open internal features that are resistant to clogging for liquids with suspended particles.

The HollowStream Cone Nozzles produce a ring of liquid rather than a full cone. As such,  their overall liquid flow volume will generally be less than that of the FullStream coutnerparts. Both the FullStream and HollowStream nozzles work very well with liquids containing particulates.

The nozzles are manufactured out of Type 303 stainless steel for durable and rugged applications up to a maximum temperature of 800°F. With absolutely no moving parts, these nozzles are Built to Last. All sizes are available in stock to ship today with an order in by 2:00 EDT.

Tyler Daniel, CCASS

Application Engineer

E-mail: TylerDaniel@EXAIR.com

Twitter: @EXAIR_TD