Author: Darryl Frierson
Choosing between a refrigerated or desiccant air dryer is dependent on the acceptable moisture content or pressure dew point (PDP) requirement for your application.
Refrigerated air dryers are typically adequate for general purpose compressed air applications and will typically offer anywhere from a 35-40° F pressure dew point (PDP). Cost is typically much less than that of other drying technologies. Refrigerated dryers use a refrigeration compressor and heat exchanger to cool the compressed air and remove moisture. There are two types of refrigerated dryers. The first type is cycling, which is the more energy efficient option and typically used for higher flows and where the flow rate varies from shift to shift. The Cycling or VSD refrigerated dryer, cycles on and off to deliver the correct PDP at the varying flow rate. The other and less expensive option is a non-cycling type. Non-cycling dryers are on all the time and run at the same load as long as they are switched on. The difference between the two, is like running your home refrigerator. You only open it when needed, and thus it “cycles” on and off as needed. Leave the door open all the time, and now you have a “non-cycling” refrigerator. Both types of dryers should have a coalescing pre-filter to remove large quantities of water droplets and oil mist before going into the air dyer. This helps the air dryer to be more efficient in removing moisture from the compressed air. After the dryer, “after-filters” can clean up the remaining oil-mist, particles and hydrocarbons. The type of final filter(s) is dependent upon your air systems’ ISO Air Quality Standard.
Desiccant compressed air dryers are typically used when your application requires very dry compressed air or when the compressed air supply will run outside in cold environments. Desiccant dryers can achieve dew points as low as -100. In some facilities, a Desiccant Air Dryer may only be needed for certain applications and processes. As an example, an auto body shop generally will need only a refrigerate air dryer for the tools and general air uses, but will benefit from having very clean and dry air for the paint booth. Desiccant Air Dryers twin towers and passes the compressed air through a tower that is filled with desiccant. The desiccant attracts the moisture during the timed cycle and then purges, which releases the moisture to the atmosphere. While one tower is drying, the other is purging and regenerating. This type of dryer does use a portion of the dried compressed air as part of the purge cycle so you need to be sure to supply enough compressed air to supply for both your demand and the purge requirement.
The different types of desiccant dryers can include non-heated, heated purge and blower purge. More energy efficient Desiccant dryers will use heated ambient air to purge the off-line tower. Further energy savings can be achieved by using a PDP monitor connected to the dryer controller which will determine when to switch the towers to start the regeneration cycle of the spent tower. The added cost of a Blower Purge Dryer will be quickly off-set by the compressed air system energy savings in most cases.
Desiccant Air Dryers require a high-quality oil-mist removal pre-filter, and a particle filter to keep dust and very fine particles from the dryer bed from getting down-stream to the air distribution system
An air audit may be in order for your compressor system, especially if it hasn’t been carefully examined recently. While many people focus on the initial cost of purchasing an air compressor, they often forget to factor in the cost of operating the machine over the long run. Any issue within a system can reduce its efficiency, wasting air and electricity, and thereby costing you more money.
But what exactly can an Air Audit do for you? Learn more about how an Air Audit can help you maximize savings. Download "What is an Compressed Air Audit"?
Everyone is always looking for ways to effectively cut costs to become more profitable. Air compression can be an expensive commodity of not properly maintained. Leaks and worn-down parts reduce the pressure your compressor can produce. Dilapidated seals and fractured piping can fail unexpectedly, creating blow outs. Unintended downtime costs money in lost production or emergency equipment hire. And then you run the risk of physical damage and personal injury claims will pile on the costs of a faulty air compressor.
Compressed air is one of the most widely used forms of energy throughout many industries, with approximately 70% of manufacturers using a compressed air system.
Compressed air can be one of the most expensive forms of energy for manufacturing plants, often using more energy than other equipment. One horsepower of compressed air requires eight horsepower of electricity. With many air compressors running at efficiencies as low as 10 percent, there’s often plenty of room for improvement. Fortunately, 50% of compressed air systems at small- to medium-sized industrial facilities have opportunities for low-cost energy conservation.
Learn how you can save money and keep your air compression working at a premium by downloading our "10 Ways You Can Optimize Your Air Compression and Save Money".
Here are a few guidelines on how to keep your reciprocating air compressor working optimally. No matter what brand of oil-lubricated reciprocating compressor you own, doing the following three things on a regular basis will extend its working life helping to ensure a trustworthy tool for years to come:
- Change lubricant quarterly
- Purge water from tank weekly (at least)
- Change air filter quarterly
Your reciprocating air compressor is basically an engine, and as such it requires constant lubrication to prevent excessive friction from damaging the moving parts and ultimately seizing the piston/s. Non detergent lubricants are typically preferred for reciprocating air compressors, but make sure you respect the viscosity the manufacturer suggests for your particular compressor.
Regularly check the oil level to make sure you have the right amount of oil in the crankcase. While the dangers of too little oil are obvious, it’s also important not to overfill a compressor with oil. If the oil level is too high the oil can get whipped and it will foam up, losing some of its lubricating properties. In addition, it will gain volume, further increasing your problems. So keep checking with your dipstick/gauge as you refill with oil and make sure your unit is perfectly level to the ground when you do this.
These are just as easy to read as the dipstick variety. The red dot represents the “OK” mark (I don’t know why they paint it red, should’ve been green). Ideally you want to keep the oil level within the center of the dot, but as long as the level is within the dot, you are OK.
On these it’s also easier to judge the state of the oil by looking at it with a flashlight, you can often see whether it’s getting milky (water) or darker (regular wear) without having to remove a sample from the crankcase.
Tip #1-Oil is regularly lost through the exhaust and the breather hole on the crankcase. Oil also ages and because of this, you should replace the oil after a certain amount of duty hours. A good rule of thumb that will help you comply with most manufacturer’s requirements is to change your reciprocating compressor oil on a quarterly basis. The actual time depends on many factors and its best if you obtain the manual for your particular compressor for a clear indication on when to replace the oil.
To remove the old oil there’s going to be a bolt at the bottom side or the bottom of the crankcase in all reciprocating air compressors. Simply remove this bolt to allow the old oil to drain into a bucket for proper disposal. To speed up the process, make sure you remove the oil when it’s warm and remove the filling cap so you don’t draw a vacuum.=
Removing Condensate from the Receiver Tank
As the compressor’s intake happens to be ambient air, humidity in the air is sucked in on every cycle. The water vapor from ambient humidity will condense and accumulate in the tank/s. Because of this dynamic, it’s imperative to drain the tank/s at least once a week.
Draining the tank is easy. Locate the drain valve at the bottom of the tank and open it until moisture and air come out of the valve. As soon as the flow of water slows to a trickle, close the valve.
If you don’t drain the tank the condensate will rust the tank’s envelope and ultimately corrosion and rust-through will occur. The more the condensate sits in the tank, the worse it’ll get in time.
To keep condensate from building up in the receiver tank with minimal effort, include the automatic electric timer drain with your purchase of a new compressor. An electric timer drain will open at preset intervals to keep condensate from building up in the tank and finding its way down stream to the shop equipment. Zero-loss drain valves do the same thing, but they lose less compressed air pressure and also reduce the number of short cycles needed to keep the compressed air system at the pre-set level. This saves on your electricity bill.
Tip #2- Because eliminating condensate from the tank is so important to the life of your compressed air system, put a tickler on your calendar to drain the tank at least once a week –more frequently in humid environments. Better yet, automate this task by investing in an automatic tank drain.
Intake Air Filter
The intake air filter is there to stop the compressor from taking in particles of dust in the ambient air which might cause damage to the metal surfaces inside the air compressor. If the location of the compressor has a lot of dust and dirt in the air, this filter may need to be kept clean or changed more often than the manufacturer’s recommendations. Use the manufacturer’s replacement intake air filter for proper fit and filtration.
Tip #3 – Refer to your manufacturer’s recommended intake air filter replacement schedule. Replacement of your intake filter is important to keeping your air compressor in compliance with the manufacturer’s basic and extended warranty. Even if your air compressor is out of warranty,
Compressed Air is an integral part of the Fabricated Metals Industry. Premier Tool Grinding manufacturer of carbide cutting tools uses our NxB22 along with our RNE Dryer and CF Filtration system. See how we assist companies like Premier Tool in the Fabricated Metals Industry.
Many processes and applications continue to use inefficient devices to deliver the compressed air, and many companies fail to recognize the simple implementation and significant payoff of improving compressed air efficiency.
Improving compressed air efficiency, or saving more of your compressed air capacity by minimizing compressed air demand, can be realized by following some simple procedures. Though there are many actions that can be taken to further improve compressed air efficiency, some simple and effective steps can be put to action quickly.
A few things you need to do to improve the demand of your air compression: Measure the air consumption to identify sources that waste compressed air Find and fix the leaks in your compressed air system. Upgrade your blow off, cooling and drying operations using engineered compressed air products. Use intermediate storage of compressed air near the point of use Control the operating air pressure at the point of use to minimize air consumption.
Why not take your compressed air to the next level by seeing the services and products that FS-Curtis can offer?
Previously we described the 6 different types of Basic Air Compressor Controls but what kind of control would you want for your compressor. Her are few pros and cons of the controls to help you assess the needs of your compressor.
- Simple control using only a pressure switch
- Motor and compressor operate only when needed which saves energy
- Good for small compressors that are 25 HP or less (depending on application)
- Frequent starting wears down motor and compressor
- Pressure setting to stop must be higher than required system pressure to build storage and may increase energy use
- Loses of pressure control in the range of 35 psi
- Limited to small compressors
- Motor compressor runs continuously which reduces wear and tear associated with too many frequent motor starts
- Tighter range of pressure (approx 10 psi)
- Provides adequate storage and offers energy-efficient control of rotary screw, reciprocating and some centrifugal compressors
- If applied incorrectly short cycles cause premature wear and tear. There is minimal or no power savings on lubricant-injected rotary screw compressors
- There needs to be proper blow down time and the storage capacity required for lubricant-injected rotary compressors to achieve energy savings and prevent lubricant foaming
- Requires over-pressurizing to maintain minimum system pressure
- The motor and compressor run continuously reducing wear
- Tighter range of pressure control (10 PSI)
- Steady progressive capacity control that matches demand
- Pressure ratios increase as inlet pressure is throttled
- Inefficient at lower loads(lubricant-injected rotary compressors limited to 40-60% capacity; centrifugal compressors limited by potential surge and may require discharge blow off)
- Combines features of modulating, load/unload. and start/stop
- Shuts down compressors when unloaded for pre-set duration which in turn saves energy
- Better selects operation mode for small reciprocating compressors
- Makes the control complex
- The Over-run timer must be set to limit premature starting and stopping
- Energy-efficient control scheme that gets down to 50% of capacity
- Matches displacement to demand without reducing inlet pressure or increasing ratios of compression
- Makes the control complex
- High initial cost
- Only available for 50 HP+ compressors
- Energy-efficient and precise control
- Various rotating speeds and giving more displacement and power. These are directly proportional to speed rotation
- Makes the control complex
- High initial cost
- Reduced full load efficiency
- Efficiency of rotary screw compressor ends drop at lower or higher speeds
FS-Curtis and Arizona Air Compressor are proud to be the sponsor of Matt Ludlow aka Coldwater Kid. Check out some behind the scenes footage of the Coldwater Kid and the whole Top Fuel Race Team.
The Coldwater Kid Top Fuel team is heading into their seventh season of competition in sand drag racing. The Family operated team from Litchfield Park, Arizona is owned by Dwight Ludlow with his son Matthew piloting the 300” nitro-burning Top Fueler. They are three-time Dome Valley Top Fuel Shootout champions (2009, 2011, and 2013). At the 2013 Dome Valley March Madness event, Matthew piloted the Hemi-powered Fueler to his career best pass with a sizzling 2.301/162MPH blast. They also recorded the Quickest Run for Top Fuel in the 2011 race season with a 2.308/158MPH run in the final round of that season's Dome Valley Top Fuel Shootout. This team has also been featured on SPEED Channel's "Lucas Oil On The Edge" & Fox Sports Net's "Race Freaks" TV Shows during the Inaugural Dirt 300 Nitro Nationals in Albuquerque, NM. At this event, the Coldwater Kid team earned a solid runner-up finish.
Thanks you to the Coldwater Kid Racing Team (Matthew Ludlow (Driver), Dwight & Marie Ludlow (Car Owners), John Aleman (Crew Chief), and Jim Green / Charlie Starns (Crew)
Compressor controls are designed to match compressor delivery with compressed air demand, by maintaining the compressor discharge pressure within a highly specified range. This discharge pressure should be set as low as possible to minimize the energy usage.
Compressor systems are typically composed of multiple compressors delivering air to a common plant air header. The combined capacity of these machines is generally sized to meet the maximum plant air demand. System controls are almost always needed to orchestrate a reduction in the output of the individual compressors during the times of having lower demand. Compressed air systems are usually designed to operate within a fixed pressure range and to deliver a volume of air that varies with system demand. System pressure is monitored and the control system decreases compressor output when the pressure reaches a predetermined level. Compressor output is then increased again when the pressure drops to a lower predetermined level.
There are 6 basic types of individual compressor controls that a person has to take into account when looking into purchasing and using air compression:
- Turns the motor which drives the compressor on or off in response to a pressure signal (seen on reciprocating and rotary compressors)
- Allows the motor to run constantly but unloads the compressor when a predetermined pressure is reached. The compressor reloads at a predetermined lower discharge pressure. This is also sometimes referred to as constant speed or constant run control (seen on reciprocating, rotary, and centrifugal compressors).
- Restricts passage of air to the compressor to progressively reduce compressor output to a specified minimum, when the compressor is then unloaded. This is also referred to as throttling or capacity control (seen on rotary and centrifugal compressors).
- This controller is commonly seen in small reciprocating compressors, allows the selection of either Start/Stop or Load/Unload. When used in a lubricant-injected rotary compressor it provides modulation or load/unload control to a preset reduced capacity. When unloading the addition of an over-run timer will stop the compressor after running unloaded for a preset time.
- This controller allows progressive reduction of the compressor displacement without reducing the channel opening (seen on reciprocating and rotary compressors).
- This controller adjusts the compressor capacity by varying the speed of the electric motor driving the compressor in response to system signals.
Learn more about the these six basic compressor controllers and more about other FS Curtis products
4 Ways to Get High Level Rotary Air Compression for the Summer
With high summer temperatures fast approaching please make sure your Rotary Compressor is prepared for the change in climate. Here are 4 tips to keep your Rotary Compression at peak performance for the summer.
- Lubricant and Coolant Levels
Is your lubricant and coolant low? Is it due for a fluid and filters service? Please note that running FS-Curtis synthetic fluids will reduce the heat generated by your compressor. The compressor oil serves as coolant in oil flooded rotary compressors. In rotary compressors, the compressor oil is circulated 7 or more times per minute through the machine. This is why oil levels become more critical in the summer. To be sure of the condition of your air end and bearings we recommend an oil analysis by any of one of distributors.
- Air Density
In the summer your compressor will have a lower performance. Make sure you install a new intake filter for the hot summer days. Please be aware that dirtier environments require more frequent intake air filter changes.
- Having Clean Compressor Air and Oil Coolers
A clean cooler may be the difference between normal operation and a high temperature shut down. Many times synthetic compressor oils are fruitless because the oil breaks down prematurely due to overheating. To protect from high acid numbers, loss of lubricity and increased viscosity, long oil change intervals must be monitored with frequent lube analysis, particularly when exposed to high ambient temperatures. Please contact your local FS-Curtis service company for a compressor “health” check.
- Hot Ambient Air and Moisture
Most lubricated, air cooled, rotary screw compressors run 100 to 110 degrees F above the ambient temperature. If your compressor room is over 100 degrees, you are already in trouble. Cross flow ventilation is advisable in non ducted compressors. If your compressor oil sump or airend discharge is more than 120 degrees F over ambient temperature in the room, you need to find out why. FS Curtis has factory approved Air Treatment accessories to minimize moisture in your system and water in the air lines.
Small adjustments can reduce your operating pressure and energy costs while improving flow rates and output. Learn the final steps you can take to optimize your compressed air system and save energy costs. Make sure that you also know the first 5 things you can learn to "Save your Compressed Air System Operating Costs"
- Review Piping Infrastructure. Many systems aren't optimized.
A piping system design should optimize transfer of compressed air at the desired flow and pressure to the point of use. Increasing the size of a pipe from two to three inches can reduce pressure drop up to 50 percent. Shortening the distance air has to travel can further reduce pressure drops by about 20-40 percent.
The more flow through a pipe the greater the pressure drop will be. Pressure drop in a pipe increases with the square of the increase in flow, which means if the flow is doubled, the pressure drop will increase four times. Air distribution piping should be large enough in diameter to minimize pressure drop.
How can FSC features and benefits help with this step? If your compressed air piping system was installed years ago when your compressor was much smaller, this might be an indication that the distribution pipes are too small. A quick guide is to look at the air compressor outlet size. If your distribution piping is smaller than your air compressor outlet size, then it may be time to get your FS Curtis Distributor in to evaluate your piping system. If up-grades are needed, FS Curtis offers a modular, aluminum piping system that is easy to install and is a cost effective alternative to copper or steel piping.
- Change Filters Systematically. Not every once in a while.
Inspect and replace filters systematically to ensure the quality of your air and prevent pressure drops. Go beyond the air compressor and compressor room. There are several air-line and point-of-use filters within the facility. Those are just as important to maintain as the air compressor and air compressor room filters.
How can FSC features and benefits help with this step? Your FS Curtis Distributor will provide you with a complete Filter Package located on your compressed air system supply side. Your process and type of equipment used will determine the level of air quality needed. If you are not sure what you need, ask your FS Curtis Distributor who can guide your selection using an industry standard selection chart.
- Recover Heat. Compressing air generates heat - reuse it!
It's simple physics that compressing air gives off heat, and as much as 90 percent of that heat can be recovered for use in your operation. For example, you can produce hot water for washrooms or direct warm air into a workspace, warehouse, loading dock, or entryway. The savings can really add up.
How can FSC features and benefits help with this step? A simple heat recovery step can be making sure the hot air from your compressor room is directed into a nearby work space. If you have a larger rotary screw compressor with and e-COOL® Technology, you may find capturing the exhaust air from your air compressor and ducting into your facility during the heating season. More aggressive heat recovery systems can be used to pre-heat water or process materials if you operate larger compressor systems.
- Emphasize Proper Maintenance. Ignoring maintenance costs more.
As with most industrial machinery, a compressor runs more efficiently when properly maintained. Proper compressor maintenance cuts energy costs around one percent and helps prevent breakdowns that result in downtime and lost production. Protect your reputation and profits with proper maintenance.
How can FSC features and benefits help with this step? Your FS Curtis i-Command® Touch Control will help monitor your compressor for items needing maintenance as well as sending signals showing maintenance alerts. Having your FS Curtis Distributor establish a scheduled service interval based on the number of hours your compressor runs per year will save you money in the long run. Take advantage of your Extended Warranty by using correct parts and lubricants at the correct time. If you skip service and don’t do maintenance, then you can expect that future warranty claims if needed, may be rejected. Just like you car, if you don’t take care of it, it won’t take care of you!
- Identify and Eliminate Inappropriate Uses of Compressed Air.
Inappropriate uses of compressed air include any application that can be done more effectively or more efficiently by a method other than compressed air. For example, high pressure air often is used for cooling or applications where much lower air pressure is required.
How can FSC features and benefits help with this step? Your FS Curtis Distributor can help you with this. If you have a Compressed Air Leak Survey scheduled, the Auditor normally is looking for inappropriate uses of compressed air at the same time. Common mis-uses are: blowing off a work station with an air gun instead of using a hand brush; using an air stream as a personal cooler instead of a fan; Plus many, many more ways…..
The first step to reduce compressed air energy costs is to measure and monitor your compressed air system's energy consumption, flow rates and operating air pressure. Your FS-Curtis Distributor can help you with your understanding of your compressed air system through an assessment or audit of your system. The FS-Curtis Distributor will provide you with a report which will help you see how your air compressor(s) are being controlled, how much energy they are using, and how much air flow and pressure you system is using. Recommendations can be made to help your reduce your operating costs and return those losses back into profit for your business. Small adjustments can reduce your operating pressure and energy costs while improving flow rates and output. Here are 10 steps you can take to optimize your compressed air system and save energy costs.
- Turn It Off.
There are 168 hours in a week, but most compressed air systems only run at or near full capacity between 60-100 hours. Depending on your shift pattern, turning your compressors off during the evenings and weekends could reduce your energy bills up to 20 percent.
How can FSC features and benefits help with this step? Here’s a suggestion to help you turn off your compressor effortlessly. Look into the FS Curtis Nx Series of Air Compressors using the i-Command® Touch Control. This advanced compressor controller can be set to turn off your air compressor at the end of a shift or work day automatically. Another energy-saving option i-Command® Touch Control is to allow the system to reduce the system pressure during non-production hours. Let’s say you operate several CNC machines which need to keep 80 psi in order to maintain the tool settings. So your i-Command® Touch Control can be set to reduce the system pressure down to the 80 psi range during your off shifts. This saves you electric costs because for every 2 psi you can drop your system pressure, you reduce your electric costs by 1%. So that 20 psi reduction just reduced your electric usage by 10% for the non-productive hours…
- Fix Existing Leaks.
A quarter-inch air leak at 100 psi will cost you more than $2,500 a year. Pipe systems, hose connections, and filter/regulator housings older than five years can have leaks of up to 25 percent. Because it takes energy to generate compressed air, any air that leaks is money wasted. Approximately 80 percent of air leaks are not audible, so to minimize these problems, third-party help in detecting these leaks may be a necessity.
How can FSC features and benefits help with this step? Your local FS Curtis Distributor can help you with a leak survey using an ultra-sonic leak detector. They can find leaks in your system and pneumatic equipment without shutting down your production. The survey will provide you with a list of items needing attention and repair. Your utility may offer a cost sharing program to help pay for the survey. You can have your maintenance team make the repairs or have your FS Curtis Distributor make the repairs.
- Prevent New Leaks.
As Benjamin Franklin said, “An ounce of prevention is worth a pound of cure.” So, be proactive and look inside your piping system. A clean, dry pipe indicates good quality air and no corrosion issues. Dust in the pipe is caused by particles in the compressed air. If compressed air is not filtered, or if the filter is clogged, pressure drops will occur and the risk of end product contamination will increase. Sludge in the pipe is bad news and must be fixed immediately. Dust and sludge in a compressed air piping system will cause corrosion very quickly and will greatly increase the number of leaks. Dried and filtered compressed air keeps piping clean.
How can FSC features and benefits help with this step? Your FS Curtis Distributor will often recommend installing a Flow Meter at the point where your compressed air leaves the compressor room and flows to the “Demand Side” of your air system. Some Flow Meters can be tied into your building’s data logging equipment. If you don’t have a data logging system, just setting up a simple log sheet so when your maintenance staff make their daily check on the air compressor, they can write down the flow rate seen on the Flow Meter screen. If you start to see an increase in the Flow numbers, it’s time to start to investigate. Did you add new equipment that takes more air? Did a process change? If nothing changed, its time to look for air leaks again!
- Reduce Pressure. Run at required pressures, not beyond.
Each two psi reduction cuts energy consumption one percent. Check the system pressure and resist the urge to turn up the pressure to compensate for leaks or drops in pressure due to piping problems or clogged filters. A central supply side controller can greatly reduce the operational pressure band and orchestrate air production much more efficiently and effectively.
How can FSC features and benefits help with this step? Your FS Curtis Distributor is a good resource to help you. They can help you establish a pressure profile of your facility. Let them help you find what process or equipment is needing the highest pressure. Often we find air supply systems running at 15 to 50 psi higher than what is really needed. A simple DemandSmart® Flow Controller may help you manage your demand side pressure and flow. Not only will you reduce your energy bill, but your facility may have less wear on air tools and improve your product quality due to a constant air pressure in our plant. Have your FS Curtis Distributor include checking needed down-stream point of use filters for pressure drop and clogged filters. Sometimes folks crank up the pressure to get more pressure to the equipment, when a change in the filter element is really needed.
- Check Drains. Are your condensate drains stuck open?
Condensate drains on timers should be adjusted periodically to ensure they open as intended or aren't stuck open. Better yet, replace timer drains with zero-loss drains to stop wasting compressed air.
How can FSC features and benefits help with this step? First, when you purchasing a new air compressor select an energy saving zero-loss drain. While the zero-loss drain may have a higher investment price, you will not be losing compressed air every time the timer opens the drain valve. The opening of the timer drain can cause the compressor to come on for a short period of time causing an unneeded motor start and extra wear on the air compressor. Always make sure your FS Curtis Distributor is checking your auto drains for correct operation when they are doing your scheduled maintenance.
This is a question that a business owner should ask… What can I do to reduce the cost of operating my Compressed Air System?
For years now, the whole industrial world has been listening to the experts that want to help you reduce your electric bill by selling you a more energy lighting system, heating and air conditioning system, speed controlled pumps, and automatic “do-dads” that promise a lower power bill. The Air Compressor industry has been drawn into this energy-saving charge because in most facilities, the electric motor in the compressed air system can be the largest and most powerful electric device in the building. So the air compressor has become one of the favorite targets of the utilities wanting to reduce the peak load on a local power grid. You’ve heard all of the sales pitches now from both the compressor guys and the power companies. But there may be low-cost actions you can take to make your compressed air system more efficient and further reduce your monthly electric bill.
First, find ways to reduce your existing air systems’ operating costs. You may not need to pay for a compressed air system audit, unless you don’t have the time or experienced staff to conduct your own system assessment. Sometimes, just focusing your facilities manager on reducing the cost of the compressed air system can work. Sometimes having a trusted air compressor vendor works well. And sometimes you may need the help of a paid compressed air auditor if you’re budget allows. However, as a starting point there are some things you can do on your own first.
According to CAGI (Compressed Air and Gas Institute), the most expensive component in the total cost of compressed air is energy. In fact, over the lifespan of a typical compressor, energy typically costs several times more than the purchase price of the compressor. The bottom line, maximizing energy efficiency saves you money.
At the beginning, you must know what your compressed air system is doing and why.
- What is the highest pressure required by your equipment and processes?
- What equipment and processes require the highest pressure?
- What machine or process truly needs that much pressure and flow?
- How clean and pure must your compressed air supply be in order to not cause product “do-over’s” caused by water or oil in the air lines?
- What is the lowest and the highest rate of flow to the demand side of the piping system, and what causes the increased demand for flow?
If you can’t answer these basic questions for your compressed air system, then you really don’t understand or manage your compressed air system effectively. And you are probably wasting a lot of money that could easily be turned into profit dollars.
The first step to reduce compressed air energy costs is to measure and monitor your compressed air system's energy consumption, flow rates and operating air pressure. Your FS-Curtis Distributor can help you with your understanding of your compressed air system through an assessment or audit of your system. The FS-Curtis Distributor will provide you with a report which will help you see how your air compressor(s) are being controlled, how much energy they are using, and how much air flow and pressure you system is using. Recommendations can be made to help your reduce your operating costs and return those losses back into profit for your business. Small adjustments can reduce your operating pressure and energy costs while improving flow rates and output.
Learn about the 10 Steps to Saving Compressed Air System Operating Costs (1-5)
The NxD45-90kW won over other compressor manufacturers. This award is noteworthy because our customers and people within our industry vote for the best product. We could not have done this without the hard work and dedication of our FS-Curtis team and the support of our global team.
The Nx Series offers a space-saving profile that’s easy to install while accommodating limited floor space. The integrated separator, MPV and thermostatic valve reduce connections by up to 90% -- meaning fewer opportunities for leaks. The Nx series also comes in variable speed drive for 8-90kW for even more efficiency and energy savings opportunities.
Learn more about the award-winning NX series and why it is a bona-fide winner!!
Let’s say you buy a Volvo, arguably considered one of the safest cars on the road, and you drive it 70 mph into a brick wall (by the way, don’t do this, it ruins the paint job), is it the car’s fault that it may no longer run?
The same scenario applies to equipment. If the OEMs installation recommendations are not adhered to, there will be a high degree of probability that the compressed air equipment will not be reliable, will not experience the stated longevity, may require above average maintenance, may consume more electrical energy than required and may not consistently provide the compressed air quality required by production.
While it’s impossible to cover all of the things you need to consider when installing a rotary air compress (and we hope it’s an FS-Curtis), this short article is intended to help avoid the equivalent of driving your car into a brick wall.
1) Have your system voltage measured. The most common electrical utility voltages in the United States are 200 volt, 208 volt, 230 volt, 460 volt. Electrical utilities guarantee a voltage supply tolerance of + 10%. For example, if the voltage stated supply is 230 volts it could measure at any given time from 207 up to 243 volts. Most electrical utilities attempt to hold the supply voltage to + 5%. Operating electrical motors off design or away from their nameplate voltage will generate additional heat leading to reduced motor life expectancy. The majority of induction motors, 5 hp through 600 hp supplied to the U.S. market, are 230 & 460 volts; however, 200 & 208 volt systems are becoming more popular. If a 230 volt name plated motor is operated on a 200 to 208 volt system it will operate in an elevated heated condition leading to extremely reduced motor life. This is not a recommended practice. There are motors specifically designed for 200 & 208 volt operation. For these applications motors name plated as such should be used.
2) Many air compressors operate into the motor service factor. As such, request the package full load operating amp draw from the manufacturer to properly size the electrical utility supply equipment (i.e., wire, electrical quick disconnect, overloads, transformers). Seek out a qualified electrical contractor in your area to assist in proper electrical utility modeling and sizing.
1) Proper placement and mounting is vital. Request a General Arrangement (GA) drawing from the OEM for each piece of compressed air equipment purchased. The GA drawing should illustrate the weight and recommended clearances to be maintained around the equipment. The floor will need to support the static weight of each piece of equipment. The equipment should be secured to the floor to prevent it from shifting around imparting stress on connected utilities such as piping, electrical and ducting. In addition, many states have adopted seismic codes mandating equipment be structurally secured to the floor. Many floors appear flat to the eye but are not flat enough to meet accepted equipment mounting practices. Many floors can be crowned (bowed) or have undulations. When securing equipment to a floor it is important to identify floor imperfections filling the air gaps with shims. When properly shimmed, the tightening of the mounting bolts will not bend or distort the equipment frame. Frame distortion will lead to excessive equipment vibration. Excessive vibration causes premature component failure which reduces machine reliability, increases cost of ownership and could potentially create an unsafe situation.
Proper clearances should be adhered to. These recommended clearances provide boundary area around the machine for safe, effective operation and servicing of the machine. This boundary area also allows adequate cooling airflow around the machine.
All piping should be properly supported as to not impart stress on the equipment. When connecting piping to the equipment pipe connector, it should be supported with proper tooling to prevent the equipment connector from turning during the piping tightening process. If the equipment receiving connector is allowed to turn (rotate) it very well could damage internal components to the equipment. Air piping should be properly sized and configured to prevent short cycling of the air compressor controls. A rule of thumb is to always use piping at least the size of the supply connection of the air compressor. If the dryer connections are larger don’t worry, the reason could be the dryer is oversized due to rerating or simply the fittings are larger to slow the compressed air velocity down through the dryer. The piping exiting the dryer can be the same size as the air compressor connection or the outlet piping size of the dryer can be used to establish the piping downstream of the dryer.
If the ambient air conditions can drop below 32°F measures should be taken to prevent the compressed air equipment from being exposed to this as it will freeze up. During air compressor operation the most effective way to condition the room temperature is to use the heat generated by the operating air compressor(s). Excessive heat can be discharged from the room by way of a properly sized wall fan. The wall fan can be thermostatically controlled to keep the room at a constant temperature. If there are times when all of the compressed air equipment is not operating, an auxiliary heating system should be considered.
Air-cooled rotary screw air compressors gives off 2545 btus/hr per horsepower.
Example: A 50 horsepower air-cooled rotary screw air compressor discharges 127,250 btus/hr into its surrounding environment.
That is enough heat to keep a 1500 square foot home comfortable in the dead of winter with outdoor temperatures below 32°F. Many of these air compressors are installed with little thought of eliminating heat build-up around the air compressor. The heat discharged into the ambient air surrounding the air compressor is continuously cycled through the heat exchangers elevating the temperature. Unchecked, the temperature will rise to an unacceptable level, eventually overheating the air compressor & shutting it down. Ducting can be attached to the air compressor to directly route the cooling air discharge outdoors or away from the air compressor. Wall or ceiling fans can also be strategically placed in the room to exhaust the hot cooling air outside. Either way, an adequate amount of replacement cooling air must be brought into the room.
All installations have contaminants in the ambient air. Contaminants can negatively impact an air compressor in many ways. Two critical ways are indigestion into the air compressor itself with the other being fouling of the air-cooled heat exchangers. The best way to determine if the air compressor is digesting an abnormally high amount of contaminants is to consistently perform oil analysis. The oil analysis should look for components not normally part of the oil make-up. The results need to be properly interpreted.
In the case of a lubricated rotary screw air compressor, all of the ambient air drawn into the machine for compression flows right past or through the airend bearings. Too much ingestion of particulate will damage the bearings. The oil not only cools the air during compression it also washes the contaminants out of the air. Over time these contaminants will build up continuing to be cycled through the bearings.
Example: A 10 micron particle should be able to flow through an anti friction bearing suspended in the oil film without damaging the bearing surfaces.
This does not account for multiple particles clumping together, which will damage the bearing surfaces. Two solutions for reducing digestion of contaminants are to install an air filter with a lower micron rating and higher efficiency rating. The ratings should be adjusted until the oil analysis indicates the level of contaminants is satisfactory. Remember, as the rating of the inlet air filter is increased the surface area should also be increased or the air filter may have to be changed out too frequently from excessive fouling. The second solution is to relocate the inlet air filter to a remote environment which is cleaner than the immediate area around the air compressor. The piping used to remote mount the air filter should be non-ferrous. PVC works great as it is light, easy to assemble and inexpensive. Connect it to the air compressor air end with an easily removable joint in case machine repairs or troubleshooting is required. The piping i.d. should be no smaller than the i.d. opening in the OEM supplied inlet filter mounting assembly. For every 10 feet of inlet pipe run, the pipe diameter should increase one size or 1". If the inlet air filter is relocated outdoors it should be protected from digestion of rain or snow.
Relocation of the inlet air filter is a recommended solution when the surrounding ambient area around the air compressor contains hazardous vapors or fumes. There are air filters which can remove hazardous fumes or vapors; however, they are costly to purchase and maintain.
If you’d like more information about FS-Curtis rotary screw air compressors, please click on the icons below to download product literature. I you have questions or would like more information or pricing, please visit our Distributor Lookup page on our website to locate a distributor in your area.
FS-Curtis and Compressed Air Challenge have come together to provide Distributors with training and advanced training on air compressors. All of this great training and advanced instruction will take place on May 16th-18 in Philadelphia, PA. Also over the next year if you sell a Nx 60-185 HP compressor you will get your registration refunded.
The conference will be held at Courtyard Marriott in Plymouth Meeting, PA
A good accommodation option:
430 Plymouth Rd
Plymouth Meeting PA 19462
May 16th- Fundamentals of Compressed Air Systems
Find out how a compressed air system works and the benefits of optimal compressed air system performance. This initial class demonstrates how to compute the current cost of your plant's compressed air systems, how to measure and create a baseline of system performance, and how to determine the impact of different compressor control types. Learn basic approaches for cutting costs; identify steps for proper system operation, maintenance, and point-of-use accountability; and tailor a compressed air system management action plan for your plant.
May 17-18: Adv. Management of Compressed Air Systems
This is an intensive two-day training that provides in-depth technical information on troubleshooting and making improvements to industrial compressed air systems. This training is designed to help end users as well as industry solution providers learn how to: Collect and use data and tools to assess the efficiency and cost-effectiveness of a compressed air system; Develop and use a system profile; Implement a system maintenance program; Address air quality, highest pressure requirements and high-volume intermittent applications; Understand complex control system strategies; Align the supply side to demand side operation; Explain the value of heat recovery; and Successfully sell compressed air improvement projects to management. When you register, you will be sent an information packet including materials you will complete prior to the training. This information will be critical as you use data to calculate cost and performance in your specific facility.