## Compressed Air and Pneumatic Systems

Compressed air is used to operate pneumatic systems in a facility, and it can be segregated into three main sections; the supply side, the demand side, and the distribution system.  The supply side is the air compressor, after-cooler, dryer, and receiver tank that produce and treat the compressed air.  They are generally found in a compressor room.  The demand side is a collection of devices that will use the compressed air to do “work”.  These pneumatic components are generally scattered throughout the facility.  To connect the supply side to the demand side, a distribution system is required.  Distribution systems are pipes or tubes which carry compressed air from the air compressor to the pneumatic devices.  The three sections have to work together to make an effective and efficient system.

Compressed air is a clean utility that is used in many different ways, and it is much safer than electrical or hydraulic systems.  But most people think that compressed air is free, and it is most certainly not.  Because of the cost, compressed air is considered to be a fourth utility in manufacturing plants.  For an electrical motor to reduce a volume of air by compressing it, it takes roughly 1 horsepower (746 watts) to compress 4 cubic feet (113L) of air every minute to 125 PSI (8.5 bar).  With almost every manufacturing plant in the world utilizing air compressors larger than 1 horsepower, the amount of energy needed is extraordinary.

Let’s determine the energy cost to operate an air compressor by Equation 1:

Equation 1:

Cost = hp * 0.746 * hours * rate / (motor efficiency)

where:

Cost – US\$

hp – horsepower of motor

0.746 – conversion KW/hp

hours – running time

rate – cost for electricity, US\$/KWh

motor efficiency – average for an electric motor is 95%.

As an example, a manufacturing plant operates a 100 HP air compressor in their facility.  The cycle time for the air compressor is roughly 60%.  To calculate the hours of running time per year, I used 250 days/year at 16 hours/day.  So operating hours equal 250 * 16 * 0.60 = 2,400 hours per year.  The electrical rate for this facility is \$0.10/KWh. With these factors, the annual cost to run the air compressor can be calculated by Equation 1:

Cost = 100hp * 0.746 KW/hp * 2,400hr * \$0.10/KWh / 0.95 = \$18,846 per year in electrical costs.

If we look at the point-of-use or demand side, the compressed air is generally conditioned to be used to run and control the pneumatic system.  The basic units include filters, regulators, and lubricators.  The filters are used to remove any oil, water, vapor, and pipe scale to keep your pneumatic system clean.  They fall into different types and categories depending on the cleanliness level required.

Filter Separators are more of a coarse filtration which will capture liquid water, oil, and particulate.  The Oil Removal Filters are more of a fine filtration which can capture particles down to 0.03 micron.  They are also designed to “coalesce” the small liquid particles into larger droplets for gravity removal.  One other group is for removing oil vapor and smell.  This type of filter uses activated charcoal to adsorb the vapor for food and pharmaceutical industries.  Filters should be placed upstream of regulators.

Pressure Regulators change the pressure downstream for safety and control.  Pneumatic devices need both flow and pressure to work correctly.  The lubricator, which is placed after the Regulator, helps to add clean oil in a compressed air line.  Air tools, cylinders, and valves use the oil to keep seals from wearing with dynamic functions.  Once the compressed air is “ready” for use, then it is ready to do many applications.

For EXAIR, we manufacture products that use the compressed air safely, efficiently, and effectively.  EXAIR likes to use the 5-C’s; Coat, Clean, Cool, Convey and Conserve.  We have products that can do each part with 16 different product lines.  EXAIR has been manufacturing Intelligent Compressed Air Products since 1983.  Compressed air is an expensive system to operate pneumatic systems; but, with EXAIR products, you can save yourself much money.  If you need alternative ways to decrease electrical cost, improve safety, and increase productivity when using compressed air, an Application Engineer at EXAIR will be happy to help you.

John Ball
Application Engineer
Email: johnball@exair.com

## EXAIR Atomizing Spray Nozzles for Coating, Cleaning, Cooling

A recent customer in the automation / tool making industry had a need to spray a mold release agent onto some specialized tooling. Originally, the customer had planned to use some sort of pressurized sprayer. After some initial tests to prove the concept, the customer found that the moving mechanical parts of the sprayer became fouled by the release agent. And cleaning the internal parts was not easy to do.

In their search for a more permanent solution, the customer came across EXAIR Atomizing Nozzles. After going through some application type questions to narrow the focus down to one model, we determined that the customer would be best served by model AF1010SS (Internal Mix, Flat Fan Pattern Atomizing Nozzle). The customer had a couple of questions about the nozzle in order test the product.

1. Is it possible to disassemble the nozzle and clean it completely? The answer is yes, the Atomizing Nozzles can be completely disassembled to allow for cleaning, maintenance or replacement of worn parts.
2. Are the nozzles solvent resistant? The answer is also yes; the Atomizing Nozzles are made of AISI303 type stainless steel and can be cleaned with any normal solvent based cleaner.

Earlier in this article, I mentioned that we went through some application type questions. Here is a list of general questions that we normally ask a customer about their application in order to determine which in our selection would be best suited.

1. What is the volume of liquid flow (G/Hr) needed for the application?
2. What is the viscosity (cP) of the liquid being applied?
3. What are the required spray pattern, size and shape required?
4. Is the liquid under pressure (by pump or pressure pot)? If so, what is the liquid pressure?
1. Side note: we have options for non-pressurized liquid by using our siphon fed nozzles.

If you have an application where you have a liquid that needs to be applied in atomized form to a target, or perhaps a humidification application, please give EXAIR Atomizing Nozzles your consideration.

Jordan Shouse
Application Engineer

Send me an email
Find us on the Web

## No Drip, External Mix, Atomizing Spray Nozzle Overview

EXAIR’s Atomizing Spray Nozzles are used to clean, coat, or cool parts and they also lend themselves very well to humidification and dust control.  They are constructed from rugged and durable 303 SS to provide corrosion resistance and they can operate in temperatures up to 400°F (204°C). All EXAIR Atomizing Spray Nozzles are also CE compliant.

Atomizing Nozzles are separated into 5 categories – Internal Mix, External Mix and Siphon Fed, Deflected Flat Fan, and Internal Mix 360° Hollow Circular Pattern.  They are available in 1/8″, 1/4″ & 1/2″ NPT to make it easy to provide the coverage and flow rate you need for nearly any application.  For today’s focus, we will discuss the No Drip External Mix Atomizing Nozzles.

External Mix Atomizing Nozzles have the highest flow rates and are ideally suited where precise liquid flow is required and both the air and liquid are pressurized.  Also the External Mix Atomizing Spray Nozzles can easily atomize liquids with a viscosity above 300 cP (Centipoise).

Centipoise is defined as a dynamic viscosity measurement unit. A Centipoise (cP) is a non-SI (non-System International) measurement unit of dynamic viscosity in the centimeter gram second (CGS) system of units.

Our patented No Drip feature positively stops the liquid flow when the supply air pressure drops below 20 PSIG for 1/8″ NPT Nozzles or 30″ PSIG for the 1/4″ or 1/2″ NPT. By incorporating this feature into the design, it eliminates the need for any additional valves or supply lines.  They are available in flow rates that range from less than 2 GPH (7.57 LPH) for our Model EF9010SS 1/8 NPT No Drip External Mix Narrow Angle Flat Fan Pattern and up to 303 GPH (1,147 LPH) for the Model EF6010SS 1/2 NPT No Drip External Mix Narrow Angle Flat Fan Pattern.

When making a selection, below are some points to consider:

1. Volume of liquid required?
2. What is the viscosity of the liquid?
3. What type of spray pattern fits the application?

If you would like to discuss External Mix No Drip Air Nozzles or any of EXAIR’s safe, quiet & efficient compressed air products, I would enjoy hearing from you…give us a call.

Steve Harrison
Application Engineer
Send me an email
Find us on the Web

## Compressed Air Uses In Industry

From pneumatic hand tools like impact wrenches or nail guns to larger scale industrial applications like stamping presses, the use of compressed air can be found in almost any industry. In fact, it is often referred to as a “fourth utility” next to water, gas and electric.

Take for example in construction, workers will use a pneumatic riveter to join steel framing because of the power generated by the tool over an electrically powered device, not to mention it provides for a safer operation by removing an electrical hazard. Many companies use compressed air operated diaphragm pumps or air motor driven pumps to move expensive or viscous liquid from one location to another. These types of pumps are self priming drawing the liquid in and provide positive displacement meaning they fill and empty the liquid chamber with the same amount of liquid through a common inlet and outlet.

Amusement parks have used compressed air in some capacity in the operation of thrill rides like roller coasters or to enhance the effect of certain attractions. Compressed air can be found in hospitals where it is used for specialized breathing treatments or to power surgical instruments in an operating room. Educational facilities use compressed air for laboratory testing. You can even find compressed air in the tires on your car. Basically, when you think about it, compressed air is being used just about anywhere.

Here at EXAIR, we manufacture Intelligent Compressed Air Products to help improve the efficiency in a wide variety of industrial operations. Whether you are looking to coat a surface with an atomized mist of liquid, conserve compressed air use and energy, cool an electrical enclosure, convey parts or dry material from one location to another or clean a conveyor belt or web, chances are we have a product that will fit your specific need.

To discuss your particular application or for help selecting the best product, contact an application engineer at 800-903-9247 for assistance.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

Compressed Air Valves image courtesy of Shane Gorski via creative commons license.