Tag: six steps to optimizing compressed air system

6 STEPS To Optimizing Compressed Air: Step 5 – Install Secondary Receiver Tanks

Published on by johnball2014Leave a comment

Since air compressors require electricity to make compressed air, it is important to optimize your compressed air system. EXAIR has six simple steps, and following these steps will help you cut electrical costs, reduce overhead, and improve your bottom line.  In this blog, I will cover the fifth step –intermediate storage of compressed air near the point-of-use. 

I had a customer that was looking at a model 1122108, 108” (2,743mm) Super Ion Air Knife Kit.  The application was removing static and debris from insulated panels which they used for large refrigerated trailers.  They were worried about how much compressed air that it would use; and they were considering a blower-type system.  I went through the negative aspects like noise, cost, maintenance, and ineffectiveness with turbulent air flows.  But, when you are limited in the amount of compressed air, I had to look at another way.  Since the process was intermittent, I used the fifth step to optimize their system to use a much better solution for their application.  The cycle rate was 2 minutes on and 10 minutes off.  I was able to calculate the size of a secondary tank to help their compressed air system.   

Model 9500-60

I would like to expand a bit more about secondary receiver tanks.  They can be strategically placed throughout the plant to improve the “ebbs and flows” of pneumatic demands.  The primary receiver tanks help to protect the supply side when demands are high, and the secondary receiver tanks help pneumatic systems on the demand side.  They give additional capacity at the end of distribution lines.  Essentially, it is easier and more efficient for compressed air to travel out from a nearby source and into an application rather than traveling through long lengths of pipes from the distribution system.

For calculating the volume size for your secondary receiver tank, we can use Equation 1 below.  It is the same for sizing a primary receiver tank, but the scalars are slightly different.  The supply line for air drops will typically come from a header pipe and are generally smaller in diameter.  So, we have to look at the air restriction that can feed into the tank.  For example, a 1” NPT Schedule 40 Pipe at 100 PSIG can supply a maximum of 150 SCFM of air flow.  This value is used for Cap below in Equation 1.  C is the largest air demand for the machine or targeted area that will be using the tank.  If the C value is less than the Cap value, then a secondary tank is not needed.  If the Cap is below the C value, then we can calculate the tank volume that would be needed.  The other value in the equation is the minimum tank pressure.  In most cases, a regulator is used to set the air pressure for the machine or area.  If the specification is 80 PSIG, then you would use this value as P2.  P1 is the header pressure that will be coming into the secondary tank.  With this collection of information, you can use Equation 1 to calculate the minimum tank volume. 

Equation 1:

V = T * (C – Cap) * (Pa) / (P1-P2)

Where:

V – Volume of receiver tank (cubic meter)

T – Time interval (minutes)

C – Air demand for system (cubic meter per minute)

Cap – Supply value of inlet pipe (cubic meter per minute)

Pa – Absolute atmospheric pressure (Bar)

P1 – Header Pressure (Bar)

P2 – Regulated Pressure (Bar)

For this customer above, I am still working on this purchase.  But we went from a “we don’t have enough compressed air” to a “we can possibly use the better solution with the Super Ion Air Knife”.  If you find that you might be having issues with your equipment running optimally, you may be able to install a secondary receiver to your system.  EXAIR offers 60 Gallon tanks, model 9500-60, to add to those specific areas.  If you have any questions about using a receiver tank in your application, primary or secondary, you can contact an Application Engineer at EXAIR.

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

Optimization:  Step 6 – Control the air pressure

Published on by johnball2014Leave a comment

Since air compressors use a lot of electricity to make compressed air, it is important that you use it as efficiently as possible.  EXAIR generated a chart with six simple steps to optimize your compressed air system.  Following these steps will help you to cut overhead costs and improve your bottom line.  In this blog, I will cover the sixth step; controlling the air pressure at the point of use.

Pressure Regulators

One of the most common pressure control devices is called the Regulator.  It is designed to reduce the downstream pressure that is supplying your system.  Regulators are commonly used in many types of applications.  You see them attached to propane tanks, gas cylinders, and of course, compressed air lines.  Properly sized, regulators can flow the required amount of gas at a regulated pressure for safety and cost savings.

EXAIR designs and manufactures compressed air products to be safe, effective, and efficient.  By replacing your “old types” of blowing devices with EXAIR products, it will save you much compressed air, which in turn saves you money.  But, why stop there?  You can optimize your compressed air system even more by assessing the air pressure at the point-of-use.  For optimization, using the least amount of air pressure to “do the job” can be very beneficial and practical.

Model 1100

Why are regulators important for compressed air systems?  Because it gives you the control to set the operating pressure.  For many blow-off applications, people tend to overuse their compressed air.  This can create excessive waste, overwork your air compressor, and steal from other pneumatic processes.  By simply turning down the air pressure, less compressed air is used.  As an example, a model 1100 Super Air Nozzle uses 14 SCFM of compressed air at 80 PSIG (5.5 bar).  If you only need 50 PSIG (3.4 bar) to satisfy the blow-off requirement, then the air flow for the model 1100 drops to 9.5 SCFM.  You are now able to add that 4.5 SCFM back into the compressed air system. And, if you have many blow-off devices, you can see how this can really add up.

In following the “EXAIR Six Steps To Optimizing Your Compressed Air System”, you can reduce your energy consumption, improve pneumatic efficiencies, and save yourself money.  I explained one of the six steps in this blog by controlling the air pressure at the point of use.  Just as a note, by reducing the pressure from 100 PSIG (7 bar) to 80 PSIG (5.5 bar), it will cut your energy usage by almost 20%.  If you would like to review the details of any of the six steps, 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

Opportunities To Save On Compressed Air

Published on by Russ BowmanLeave a comment

Even casual readers of the EXAIR Blog will notice that we Application Engineers are keen on efficiency.  I just counted sixty-seven blogs on the site that discuss our Six Steps To Optimizing Your Compressed Air System.  Some offer a broad overview, while others focus on specific steps, and one tells us more than I ever expected to learn from an engineering blog about…Bigfoot.

I’m going to take a different tack here – no; I’m not going to write about the Yeti or the Loch Ness Monster, but I may try to get the Jersey Devil into a blog someday.  I will, instead, relate some real-life examples of the success of implementing each individual step.  It’s important to note here that they don’t have to be done in order, or even in total, to achieve impressive results.

  1. Measure the air consumption to find sources that use a lot of compressed air.  Like I just said, you don’t HAVE to do these steps in order, but if you DO intend to pursue a comprehensive solution, this is where you want to start.  The facility manager of a large manufacturing plant did just that when a series of Digital Flowmeters were installed in the branch lines to their production cells.  By comparing their present-day actual usage to the original design specifications, they noticed that usage in a certain cell (due to business growth) had increased to the point that they had raised the main header pressure in an attempt to keep point-of-use pressures at proper levels.  By installing a larger diameter branch line to that cell, they were able to reduce main header pressure from 120psig to 100psig, reducing their compressors’ energy usage (and their share of the electric bill) by 10%.
    Summing Remote Display (left) for remote indication and totalizing data. USB Data Logger takes data from the Digital Flowmeter to your computer and outputs to its own software (shown above) or Microsoft Excel.
  2. Find and fix the leaks in your compressed air system.  A factory once noticed they were losing header pressure overnight, when they were closed.  Using an Ultrasonic Leak Detector, they identified some small leaks that nobody thought were all that significant…until they did the math, comparing previous compressed air consumption (including those leaks) to that of their “new and improved” leak-free system.  Fixing those leaks saved them just over a million cubic feet of compressed air a year.  The exact figure was 1,062,500 cubic feet, annually.  I know this is accurate, because it was us.

  3. Upgrade your blowoff, cooling and drying operations using engineered compressed air products.  This could apply to almost every single order we process, so I’m going use an example from my first day here.  During training, I learned that a customer had recently called to get air consumption data on some EXAIR products they were going to implement as part of an upgrade that was also going to involve purchasing a new compressor.  Their main usage was a number of open-end blow offs that ran continuously.  After outfitting those with Model 1100 Super Air Nozzles and Model 9040 Foot Pedals (so the operators had simple, hands-free control over blowing cycles), they not only found they didn’t need a new air compressor, but were able to shut down an existing 50HP air compressor.
    Foot Pedal + Air Hose + Super Air Nozzle = Instant Blow Off System!
  4. Turn off the compressed air when it isn’t in use.  There are a few methods for doing this, and they’re all pretty easy:
    • Good.  Manual shutoff valves (1/4 turn ball valves are great for this) can be used by mindful operators to shut off compressed air use between production cycles, during lunch breaks, and (I hope this is patently obvious to the most casual observer) at closing time.  I’ve talked to users about doing this, but I don’t have any great success stories about this method.  It relies on someone’s memory in knowing when to operate the valve…and nobody’s remembered to call me back with a full report either.
    • Better.  If you only need air blowing while a machine is running,
      EXAIR stocks Solenoid Valves in a variety of sizes & voltages

      most any qualified industrial electrician can wire a solenoid valve into the on/off control of the machine.  Better yet, if the system has programmable logic control (PLC), it can be used to open & shut that same solenoid valve, to effect blow off only as needed.  I worked with an automotive parts manufacturer who had a robot passing parts between a pair of Model 110042 42″ Aluminum Super Air Knives.  They had taken care to accurately position the Air Knives, and program the robot’s movement & speed, to optimize blow off…but the Air Knives were running continuously.  After a brief conversation with the line foreman, they bought and installed a Model 9065 1 NPT 24VDC Solenoid Valve and “told” the PLC to turn air flow on as the robotic arm approached the Air Knives, and turn it off right after the part had passed through.
    • Best.  In the absence of programmable logic, the simplicity of the EXAIR EFC Electronic Flow Control just can’t be beat.  It’s a standalone system that consists of a Solenoid Valve that’s operated by a photoelectric sensor and controlled by a programmable timer.  Whether it’s a tenth of a second, or a few minutes, waste is waste, and it adds up.  Consider this application writeup from our Optimization Products catalog section:
      Turning air off when it’s not needed adds up, even if it’s just for a few seconds at a time.

       

       

       

  5. Use intermediate storage of compressed air near the point of use.  If
    Prevent intermittent demands from starving other loads with intermediate storage.

    compressed air is used in any sizable amount in your facility, odds are, you have a compressor room.  If it’s done right, this is a good thing for your compressor, but it CAN present some challenges for distribution over large areas.  A user of EXAIR Super Ion Air Knives, for example, installed a Model 9500-60 Receiver Tank in an area some distance from the compressor room to maintain higher air pressure than line loss (from the length of the header pipe) was allowing.  Their other option was to increase their overall header pressure; this allowed them to maintain current costs…increasing system pressure by 2psi equates to a 1% increase in compressed air generation costs.
  6. Control the air pressure at the point of use to minimize air consumption.  In addition to controlling OVERALL compressed air system pressure (see examples 1 & 5 above), using Pressure Regulators to control the supply pressure to specific compressed air operated products will save you money too…the lower the supply pressure, the lower the consumption.  A Model 1101 1/4 MNPT Super Air Nozzle, for example, uses 14 SCFM when supplied at 80psig…that’s where we publish its performance, because that’ll give a good, strong blast of air, suitable for a wide range of typical industrial air blowing applications. A tube manufacturer once replaced two open blow off devices that used about 38 SCFM each with Model 1101’s.  Even though that cut their air consumption by more than half, they were able to cut it even further by regulating the supply pressure to 56psig…that’s the pressure at which they could still get the job done consistently, resulting in ANOTHER 25% reduction in compressed air consumption.

If you’d like to find out more about any, or all, of the Six Steps To Optimizing Your Compressed Air System, give me a call.

Russ Bowman, CCASS

 

 

 

Application Engineer
EXAIR Corporation
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Opportunities to Save On Compressed Air

Published on by johnball2014Leave a comment

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