Opportunities to Save On Compressed Air

Since air compressors use a lot of electricity to make compressed air, it is important to use the compressed air as efficiently as possible.  EXAIR has six simple steps to optimize your compressed air system.  (Click HERE to read).  Following these steps will help you to cut your overhead costs and improve your bottom line.  In this blog, I will cover a few tips that can really help you to save compressed air.

To start, what is an air compressor and why does it cost so much in electricity?  There are two types of air compressors, positive displacement and dynamic.  The core components for these air compressors is an electric motor that spins a shaft.  Like with many mechanical devices, there are different efficiencies.  Typically, an air compressor can put out anywhere from 3 SCFM per horsepower to 5 SCFM per horsepower.  (EXAIR settles on 4 SCFM/hp as an average for cost calculations.)  Equation 1 shows you how to calculate the cost to run your air compressor.

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 $0.08/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 * $0.08/KWh / 0.95 = $15,077 per year in just electrical costs.

There are two major things that will rob compressed air from your system and cost you much money.  The first is leaks in the distribution system, and the second is inefficient blow-off devices.   To address leaks, EXAIR offers an Ultrasonic Leak Detector.  The Ultrasonic Leak Detector can find hidden leaks to fix. That quiet little hissing sound from the pipe lines is costing your company.

A University did a study to find the percentage of air leaks in a typical manufacturing plant.  For a poorly maintained system, they found on average that 30% of the compressor capacity is lost through air leaks.  Majority of companies do not have a leak preventative program; so, majority of the companies fall under the “poorly maintained system”.  To put a dollar value on it, a leak that you cannot physically hear can cost you as much as $130/year.  That is just for one inaudible leak in hundreds of feet of compressed air lines.  Or if we take the University study, the manufacturing plant above is wasting $15,077 * 30% = $4,523 per year.

The other area to check is air consumption.  A simple place to check is your blow-off stations.  Here we can decide how wasteful they can be.  With values of 4 SCFM/hp and an electrical rate of $0.08/KWh (refence figures above), the cost to make compressed air is $0.25 per 1000 ft3 of air.

One of the worst culprits for inefficient air usage is open pipe blow-offs.  This would also include cheap air guns, drilled holes in pipes, and tubes.  These devices are very inefficient for compressed air usage and can cost you a lot of money.  As a comparison, a 1/8” NPT pipe versus an EXAIR Mini Super Air Nozzle.  (Reference below).  As you can see, by just adding the EXAIR nozzle to the end of one pipe, the company was able to save $1,872 per year.  That is some real savings.

 By following the Six Steps to optimize your compressed air system, you can cut your energy consumption, improve pneumatic efficiencies, and save yourself money.  With the added information above, you can focus on the big contributors of waste.  If you would like to find more opportunities to save compressed air, you can contact an Application Engineer at EXAIR.  We will be happy to help.

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

Intelligent Compressed Air: Rotary Air Compressors

Air Compressor
Air Compressor and Storage Tanks

One thing that is found in virtually every industrial environment is an air compressor. Some uses for the compressed air generated are: powering pneumatic tools, packaging, automation equipment, conveyors, control systems, and various others. Pneumatic tools are favored because they tend to be smaller and more lightweight than electric tools, offer infinitely variable speed and torque, and can be safer than the hazards associated with electrical devices. In order to power these devices, compressed air must be generated.

There are two main categories of air compressors: positive-displacement and dynamic. In a positive-displacement type, a given quantity of air is trapped in a compression chamber. The volume of which it occupies is mechanically reduced (squished), causing a corresponding rise in pressure. In a dynamic compressor, velocity energy is imparted to continuously flowing air by a means of impellers rotating at a very high speed. The velocity energy is then converted into pressure energy. We’ve discussed the different styles of air compressors here on the EXAIR Blog in the past. Today I’d like to highlight the rotary compressors, one of the positive-displacement types of compressors.

Positive-displacement compressors are broken into two categories: reciprocating and rotary. The rotary compressors are available in lubricant-injected or lubricant-free varieties. Both styles utilize two inter-meshing rotors that have an inlet port at one end and a discharge port at the other. Air flows through the inlet port and is trapped between the lobes and the stator. As the rotation continues, the point inter-meshing begins to move along the length of the rotors. This reduces the space that is occupied by the air, resulting in an increase in pressure.

In the lubricant-injected varieties, the compression chamber is lubricated between the inter-meshing rotors and bearings. This lubricant protects the inter-meshing rotors and associated bearings. It eliminates most of the heat caused by compression and acts as a seal between the meshing rotors and between the rotor and stator. Some advantages of the lubricant-injected rotary compressor include a compact size, relatively low initial cost, vibration free operation, and simple routine maintenance (replacing lubricant and filter changes). Some drawbacks to this style of compressor include lower efficiency when compared with water-cooled reciprocating compressors, lubricant carry over must be removed from the air supply with a coalescing filter, and varying efficiency depending on the control mode used.

In the lubricant-free varieties, the inter-meshing rotors have very tight tolerances and are not allowed to touch. Since there is no fluid to remove the heat of compression, they typically have two stages of compression with an inter-cooler between and an after cooler after the second stage. Lubricant-free compressors are beneficial as they supply clean, oil-free compressed air. They are, however, more expensive and less efficient to operate than the lubricant-injected variety.

Each of these compressors can deliver air to your Intelligent Compressed Air Products. If you’re looking to reduce your compressed air consumption and increase the safety of your processes contact an EXAIR Application Engineer today. We’ll be happy to discuss the options with you and make sure you’re getting the most out of your compressed air usage.

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

EXAIR’s Return on Investment For One Engineered Air Nozzle is Amazing!

Return on Investment (ROI) is a measure of the gain (preferably) or loss generated relative to the amount of money that was invested.  ROI is typically expressed as a percentage and is generally used for financial decisions, examining the profitability of a company, or comparing different investments.  It can also be used to evaluate a project or process improvement to decide whether spending money on a project makes sense.  The formula is shown below-

ROI
ROI Calculation
  • A negative ROI says the project would result in an overall loss of money
  • An ROI at zero is neither a loss or gain scenario
  • A positive ROI is a beneficial result, and the larger the value the greater the gain
1100group
Our catalog publishes most products’ performance and specification data for a compressed air supply pressure of 80psig.

Example – installing a Super Air Nozzles (14 SCFM compressed air consumption) in place of 1/4″ open pipe (33 SCFM of air consumption consumption) .  Using the Cost Savings Calculator on the EXAIR website, model 1100 nozzle will save $1,710 in energy costs. The model 1100 nozzle costs $42, assuming a $5 compression fitting and $45 in labor to install, the result is a Cost of Investment of $92.00. The ROI calculation for Year one is-

ROI2

ROI = 1,759% – a very large and positive value.  Payback time is only 13 working days!

If you have questions regarding ROI and need help in determining the gain and cost from invest values for a project that includes an EXAIR Intelligent Compressed Air® Product, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.

Jordan Shouse
Application Engineer

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Find us on the Web 
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Twitter: @EXAIR_JS

Do I Have To Install A Compressed Air Filter?

2″ Heavy Duty Line Vac Kit – Model 152200

Recently I took a call from an existing customer that is questioning their Heavy Duty Line Vac Kit setup. They are experiencing around a 38 psig pressure drop from before the filter in the system to the inlet of the Line Vac.  At first glance, they assumed this was due to the filter restricting the flow. They then posed the question, “Do I have to run this filter or can I take it out?  I mean I already have a filter at my compressor.” The answer is yes, install the filter. It will keep dirt, scale and condensate from entering the Line Vac or other components downstream. In the case of a Line Vac, a filter will also prevent this unwanted debris from getting into the material being conveyed.

Example of an Improper Filter Setup

However, this is a great question, especially when assuming the filter is causing the pressure drop – but that was not the case for this application.  So more questions were asked to our customer to determine what the root cause of the pressure drop could be. Seeing a pressure drop across a filter can be caused by several factors.

One would be an inappropriately sized filter. This can restrict the volumetric flow of air through to the point of use causing a pressure drop.  All of the filters supplied with our product kits are auto-drain, have 5 micron filter elements and appropriately sized to operate the product at 80 psig inlet pressure so this was not the problem.

The next issue could be that the filter is clogged, this brought on another question.  If you see more than a 5 psig pressure drop across a filter from EXAIR then we suggest changing out the filter element as it could be clogged and not permitting the full volumetric flow through.  This installation was fairly new and a quick test without a filter element installed proved it was not the filter element that was clogged.

That brought us to the last variable, the length, size, and number/type of fittings between the filter and the Heavy Duty Line Vac. This length of pipe was more than 30′ in length and was only appropriately sized for a 10′ length or shorter run.  The customer was using a 1/2″ Schedule 40 black iron pipe to feed a 2″ Heavy Duty Line Vac at 80 psig inlet pressure. The 2″ Heavy Duty Line Vac Kit will utilize 75 SCFM at 80 psig inlet pressure.  That will need a 1/2″ Sched. 40 pipe that is 10′ long or less in order to not have friction loss within the feed pipe.  Armed with this information the customer is researching whether or not the line needs to stay that long.  If it does, they will have to re-plumb the system with a minimum of a 3/4″ Sched. 40 black iron pipe.

Luckily this was all able to be discussed within a few hours of time and the customer is on their way to an optimal supply system for their in-line conveyor.  One brief phone call took this customer from lackluster performance and thinking a product was not going to work for what they need, to performing beyond their expectations, and being able to keep up with their production needs.

If you have a product or any part of your compressed air system that you question why it may be performing or not performing a certain way, please do not hesitate to reach out to our knowledgeable team of Application Engineers. We are always interested in finding a solution to your needs.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

EXAIR Products: The Importance of Oil Removal Filters

Oil Removal Filter
Oil Removal Filters

EXAIR’s Intelligent Compressed Air Products have no moving parts and require no maintenance. Most EXAIR products require no direct maintenance, and will continue to require no maintenance if the supplied air is clean. Keeping air clean, in EXAIR’s case, can be done with a simple water/dirt or oil filter separator close to the application of the product – usually within 10 feet. The reason for the filters is that many products have very tight orifices that could get clogged from contaminants such as particulate, condensate, and lubricant.

Oil is commonly present in a compressed air supply, whether that’s intentional or not. Many air compressors are lubricated by a constant supply of oil, inevitably some of this oil ends up in the air supply. As the compressor wears, more oil is permitted to pass and ends up in the distribution system. While this is kept to a minimum with proper maintenance, it is impossible to prevent unless using an oil-free compressor.

Sometimes oil is present in the air supply intentionally. Many pneumatic devices require a precise amount of oil to keep the internal moving parts lubricated. In the case of EXAIR Intelligent Compressed Air Products, we recommend particulate-free, moisture-free, and oil-free air.

EXAIR offers a line of Oil Removal Filters. These coalescing style filters are used to remove very fine water vapor as well as any residual oil. These filters are highly recommended to be installed just prior to dryers that contain a media that would be compromised by lubricant passing through it. Coalescing filters utilize an element typically made up of glass fibers that “coalesce”, or combine, the fine water vapor and oil aerosols until the droplet size becomes large enough that it drops off into the filter bowl. With a coalescing filter, the most common cause of pressure drop increase is due to particulate clogging the element. Because of this, a particulate filter should always be installed just prior to coalescing filters. Check out this video demonstrating an Auto-Drain Filter and Oil-Removal Filter in action:

Without filtration, oil in the air supply will pass through the point of use device and into your product or process. The elimination of this problem is such a simple solution. Don’t neglect your compressed air system and ensure you’re delivering clean, dry, oil-free air to all of your EXAIR Intelligent Compressed Air Products.

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

The Bernoulli Principle

When catapults would hurl stones and projectiles at castles there weren’t thinking of how the stones flew or what could make them fly better, often they went with the “Tim Taylor method” of MORE POWER.  It wasn’t until thousands of years later that mathematicians started to talk about gases and liquids and how they react to different scenarios. Things like how does air react to a stone being launched through it. Johann Bernoulli played a significant role and calculated a lot of this out throughout his life and discovered what is now called the Bernoulli Principle.

Bernoulli discovered that when there is an increase in the speed of a fluid, a simultaneous decrease in fluid pressure occurs at the same time. This is what explains how a plane’s wing shape matters. It also can showcase how a curveball coming into the strike zone can fall out and cause an outlandish “STTTeeerriike Three” from the umpire. It is also sometimes confused with the Coandă effect. While both effects have a tremendous impact on our modern lives, the best way I have learned these effects is through videos such as the one below.

As mentioned within the video, there are numerous effects that can closely relate to the Bernoulli effect, the best example I see is the curveball which when implemented correctly can cause a very upset batter, while the pitcher has the game of his or her career.

If you would like to talk about some scientific discoveries that have you puzzled, or if you want to figure out how we can use one of these effects to help your application, contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Video Source: Fizzics Organization – 10/8/2014 – retrieved from https://www.youtube.com/watch?v=-c_oCKm5FLU&list=PLLKB_7Zd6leNJmORn6HHcF78o2ucquf0U