Compressed Air and Pneumatic Systems

Compressed Air Pipe

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.

Filters and Regulator

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
Twitter: @EXAIR_jb

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.

No Drip Atomizing Nozzle
No Drip Atomizing Nozzle

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

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EXAIR Super Air Amplifiers – Circulate, Blow, Dry, Cool, Vent

Super Air Amplifier

EXAIR manufactures a volume-type amplifier called the Super Air Amplifier. Not to be confused with its cousin, the pressure-type amplifier which increases air pressure, these devices increase the volume of air. This is a great benefit for circulating, cooling, blowing, drying and transferring materials like smoke fumes or lightweight items. With a range of applications, the EXAIR Super Air Amplifiers can be a simple solution for your company.

Super Air Amplifier – flow region

Why an EXAIR Super Air Amplifier? Like a fan, they are designed to move air. But fans use motors and blades to push the air toward the target. The fan blades “slap” the air which creates turbulent air flows and loud noises. The Super Air Amplifiers does not have any blades or motors to move the air. It just uses a Coanda profile and a patented shim to create a low pressure to draw in the air. With physics, it is much easier to pull than it is to push. The method in pulling air through the Super Air Amplifier makes a more efficient, uniform, and quiet operation to blow air.

How It Works

To expand, Coanda was named after a Romanian aerodynamic pioneer, Henri Coanda where he found a fluid flow phenomenon. He stated that “a jet of fluid emerging from an orifice to follow an adjacent flat or curved surface and to entrain fluid from the surroundings so that a region of lower pressure develops” (1). Since air is a fluid, it will react in the same way. The EXAIR Super Air Amplifiers create a high velocity air stream along an engineered profile. So, as the air “hugs” the profile, a low pressure is created which will draw in ambient air. The ratio between the volume of air produced compared to the volume of compressed air needed is called the amplification ratio. The higher the ratio, the more efficient the blowing device is. With the EXAIR Super Air Amplifiers, we can reach amplification ratios up to 25 to 1.

Super Air Amplifier Family

EXAIR manufactures and stocks five different sizes ranging from ¾” (19mm) up to 8” (203mm) in diameter. One of the unique features with the Super Air Amplifiers is that the inlet and outlet can be ducted for remote positioning. They are very compact and can fit into tight places. They do not have any moving parts to wear, or need electricity to run; or require any maintenance. They only need clean compressed air to work. One of the unique features of the EXAIR Super Air Amplifier is the patented shim which optimizes the low-pressure to draw in more ambient air. For extracting welding smoke, increasing cooling capacities, and moving material from point A to point B; the more air that can be moved, the better the performance. And the patented shim inside the EXAIR Super Air Amplifiers provides that. As an added bonus, they are OSHA compliant for safety and meet the standards for noise level and dead-end pressure.

Patented Air Amplifier Shims

EXAIR offers the Super Air Amplifiers in kits for a more complete system. The kit will include a filter separator, a pressure regulator and a Shim Set. The filter can remove debris and water from the compressed air line to keep the Super Air Amplifier and your product clean. The regulator is used to make “fine” adjustments to the blowing volume while the Shim Set is used as a “coarse” adjustment. The Shim Set includes different thicknesses of shims to set the gap. The Super Air Amplifiers come standard with a 0.003” (0.08mm) thick shim for the sizes ¾” (19mm) up to 4” (102mm), and a 0.009” (0.23mm) thick shim for the 8” (203mm) size. The Shim Set will include (1) 0.006” (0.15mm) and (1) 0.009” (0.23mm) shim for the models 120220 through 120224 or (1) 0.015” (0.39mm) shim for the model 120228. EXAIR sells these kits as one model number for simple ordering and for proper sizing of the accessories to not hinder the performance of the Super Air Amplifiers.

120224DX

To optimize the system even more, EXAIR also offers a Deluxe Kit for the Super Air Amplifier models. This will include the accessories in the kit above, plus an Electronic Flow Control, or EFC. This exclusive instrument uses a photoelectric eye to start a timing sequence to control a solenoid valve. So, when a part is not in front of the Super Air Amplifier, the compressed air is turned off. This will save you even more money and maximize your efficiency to only blow air when needed. They can be ordered with the kits by placing a “DX” at the end of the model number, such as 120224DX.

With the today’s cost to make compressed air, it is important to use it as efficiently as possible. The EXAIR Super Air Amplifiers have the ability to give effective blowing to remove debris, dry parts, transport material, or cool objects without using a large amount of compressed air. EXAIR has the Super Air Amplifiers in stock and as always, EXAIR offers a 30-day unconditional guarantee for our customers in the U.S. and Canada to try them out. If you have any questions about the Super Air Amplifiers or if you would like to discuss your application, an Application Engineer at EXAIR will be happy to help you.

 

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

 

(1) Note: Coanda effect by Wikipedia.org https://en.wikipedia.org/wiki/Coand%C4%83_effect

EXAIR Cabinet Cooler Systems – How Do they Work?

Cabinet Cooler systems eliminate heat related problems by providing a temperature controlled environment inside of electrical enclosures. Typically set to maintain 95F (but also adjustable) a Cabinet Cooler system can withstand harsh, remote environments with little maintenance. They cool heat loads up to 5600 Btu/Hr and are UL listed to maintain your cabinet’s NEMA integrity. 

Compressed air enters the vortex tube powered Cabinet Cooler and is converted into two streams, one hot and one cold. Hot air from the vortex tube is muffled and exhausted through the vortex tube exhaust. The cold air is discharged into the cabinet through the included cold air distribution kit. The displaced hot air in the cabinet rises and exhausts to atmosphere through the cabinet cooler body. The control cabinet is both cooled and purged with cool, clean air. Outside air is never able to enter the control panel.

sl17_Nema4
How it works! 

EXAIR’s compressed air operated, Cabinet Cooler Systems are a low cost, reliable way to cool and purge electronic control panels. There are no moving parts to wear out and no filters to replace, eliminating the need for constant monitoring.

NEMA Type 12 (IP54) and NEMA 4 and 4X (IP66) models are available that are very compact and mount in just minutes through an ordinary electrical knockout.

Cabinet Cooler Family
EXAIR Cabinet Cooler Sizes 

Available in a wide range of cooling capacities, ranging from 275 Btu/hr. for our smallest system, up to 5,600 Btu/hr. for our largest Dual System.

Thermostat control systems are the most efficient way to operate a Cabinet Cooler as they limit compressed air use by operating only when the temperature inside the enclosure approaches critical levels. Continuous Operating Systems are recommend when constant cooling and constant positive pressure inside the panel is required.

Thermostat controlled Cabinet Cooler Systems are the best option when experiencing fluctuating heat loads caused by environment or seasonal changes. Thermostatically Controlled Systems include a Cabinet Cooler, adjustable thermostat, solenoid valve, cold air distribution kit consisting of tubing and self adhesive clips to duct the cold air inside the panel and a filter separator to remove any water or contaminants from the supply.

Thermostat and ETC

If you would like to discuss our cabinet cooler systems or any of EXAIR’s engineered solutions, I would enjoy hearing from you…give me a call.

Jordan Shouse
Application Engineer
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