A manufacturer of high speed industrial machinery makes a sorting machine for seeds. There’s a clear plastic cover for operators to see the seeds as they pass through the machine. Many seeds are dense enough to move right on through, but some lower density seeds (canola, lettuce, and flax seed, specifically) bounce around a bit, and even the slight static charge that builds up as they move through causes them to cling to the inside of that viewing window.
This was a great fit for our Model 8406 6″ Gen4 Standard Ion Air Knife Kit…”fit” being the operative word. While the Super Ion Air Knives are more efficient and quieter, there simply wasn’t very much room at all for mounting inside, so the smaller profile of the Standard Ion Air Knife made all the difference in the world. Also, since they just need static dissipation of such a small area, and not much flow at all is required to blow off these lightweight seeds, the differences in compressed air consumption and sound level were not very much at all.
Chances are if you have been on your job for a little while, you have noticed some processes or equipment that takes excessive time, wastes energy, etc.. and delivers less than optimal results. So, just how do you communicate those observations to management in your organization? You certainly do not want to embarrass yourself by having your idea torpedoed, nor let the company continue wasting money on inefficient processes or equipment. The question becomes, how do you present your cost savings plan to the management team? This blog will help you with that very question!
Your idea(s) for cost savings should be presented clearly and concisely with some key information highlighting the cost and the savings. The simplest way to accomplish this is to quantify the savings for a given period of time and the payback schedule. The payback schedule is generally calculated by dividing the cost of the project by the forecast savings. Generally speaking, the shorter the time required for payback, the better the odds of your project being approved.
To start the process generate a (1) page overview that states the problem, cost of your proposal and the forecast savings. A thorough and concise presentation will help sway any naysayers in the group, and you should include detailed information that includes current operating costs and how you arrived at those figures.
In the compressed air industry, EXAIR Intelligent Compressed Air products provide some easy installations and quick payback times without sacrificing production or quality – in many cases, we can improve production and quality. Let’s consider the case below, where open tubes were being used to blow off punch presses. We started by capping off (4) of the open tubes and trying one EXAIR 1100 Air Nozzle with a defined air pattern and we clearly needed more force. That is when we attached the second super air nozzle, and voila! We had the amount of force and the air pattern required for this application, all while greatly minimizing air consumption and noise! The image below shows what a sample air savings presentation sheet or test sheet may look like.
Considering the EXAIR1100 Super Air Nozzle are $39 each, you can calculate that the payback time is slightly less than 10 working days per press, since two nozzles were used for each press.
When considering larger and more in-depth projects, naturally more documentation and information will be required. In addition to the requirements for the above example, just be sure to include the following points:
List the action items for your proposal and any purchases that may be necessary.
Outline your proposed savings and document how you arrived at that number.
Discuss anything that may cause delays or not go as planned, and if possible, suggest viable workarounds.
Create a milestone schedule for all the major points in your plan.
If you would like to discuss increasing the efficiency of your compressed air usage, quieter compressed air products, and/or any EXAIR product, I would enjoy hearing from you. Give me a call.
For properly designed compressed air systems, air compressors will use primary storage tanks, or receivers. They are necessary to accommodate for fluctuations in airflow demand and to help prevent rapid cycling of the air compressor. (Reference: Advanced Management of Compressed Air – Storage and Capacitance) There are two types of primary receivers, a wet receiver tank and a dry receiver tank. The wet receiver is located between the air compressor and the compressed air dryer where humid air and water will be stored. The dry receiver is located after the compressed air dryer. In this blog, I will be reviewing the wet receivers and their requirements as a storage tank.
Air compressors discharge hot humid air created by the internal compression. A byproduct of this compression is water. By placing a wet receiver on the discharge side of the air compressor, this will create a low velocity area to allow the excess water to fall out. It will also give the hot air time to cool, allowing the compressed air dryers to be more effective. With wet receivers, it will reduce cycle rates of your air compressors for less wear and store compressed air to accommodate for flow fluctuations in your pneumatic system.
But, there are some disadvantages with a wet receiver. For compressed air dryers, it is possible to exceed the specified flow ratings. If the demand side draws a large volume of air from the supply side, the efficiency of the compressed air dryers will be sacrificed, allowing moisture to go downstream. Another issue with the wet receiver is the amount of water that the air compressor is pumping into it. As an example, a 60 HP air compressor can produce as much as 17 gallons of water per day. As you can see, it would not take long to fill a wet receiver. So, a condensate drain is required to get rid of the excess water.
Condensate drains come in different types and styles. They are connected to a port at the bottom of the wet receiver where the water will collect. I will cover the most common condensate drains and explain the pros and cons of each one.
Manual Drain – A ball valve or twist drain are the least efficient and the least expensive of all the condensate drains. The idea of having personnel draining the receiver tanks periodically is not the most reliable. In some cases, people will “crack” the valve open to continuously drain the tank. This is very inefficient and costly as compressed air is being wasted.
Timer Drain Valves – These valves have an electric timer on a solenoid to open and close a two-way valve or a ball valve. The issue comes in trying to set the correct time for the open and close intervals. During seasonal changes, the amount of water going into the wet receiver will change. If the timer is not set frequent enough, water can build up inside the receiver. If too frequent, then compressed air is wasted. Compared to the manual valve, they are more reliable and efficient; but there is still potential for compressed air waste.
No-waste Drains – Just like the name, these drains are the most efficient. They are designed with a float inside to open and close a drain vent. What is unique about the float mechanism is that the drain vent is always under water. So, when the no-waste drain is operating, no compressed air is being lost or wasted; only water is being drained. The most common problem comes with rust, sludge, and debris that can plug the drain vent.
All wet receivers require a condensate drain to remove liquid water. But, the importance for removing water without wasting compressed air is significant for saving money and compressed air. EXAIR also has a line of Intelligent Compressed Air® products that can reduce your compressed air waste and save you money. You can contact an Application Engineer for more details.
The primary business benefits of an efficient air compressor system are reduced operational costs, reduced maintenance and increased up-time. With that being said, is your compressed air system costing you more than you think it should? Are you having failures, pressure drops, inadequate volume and/or pressure? You might think from these issues that your system has seen better days and is ready to be replaced. However, it is possible that your existing tried and true compressor system has more life left in it than you think and with a few simple steps you could have it performing like a champ again!
It is estimated that typically plants can waste up to 30 percent of their generated compressed air and that cost is substantial. Considering the average cost to generate compressed air is .25 cents per 1000 SCFM, that translates into .075 cents for every .25 cents spent! Considering that energy costs have doubled in the last five years, it couldn’t be more timely to make your air compressor system more efficient.
So just where is all this waste occurring? The largest source of compressed air energy waste is from unused or leaked compressed air and that is followed by line pressure drops, over pressurization and inadequate maintenance of the compressor.
So how can you identify this issues in your system?
1). Finding leaks can be accomplished by several methods such as soapy water applied to a suspected joint or connection or the EXAIR Ultrasonic Leak Detector. It is a high quality instrument that can locate costly leaks in your compressed air system. When a leak is present and audible tone can be heard in the supplied headphones and the LED display will light. This testing can be done up to 20′ away so need to get on a ladder!
2). Pressure drop is caused by is caused by the friction of the compressed air flowing against the inside of the pipe and through valves, tees, elbows and other components that make up a complete compressed air piping system. If the piping system is to small, the flow (volume) will not be sufficient and the devices will not operate properly. The volumetric demand would need to be added up to determine if the piping is of sufficient diameter to flow the required volume. EXAIR’sDigital Flow Meter is an easy way to monitor compressed air consumption and waste. The digital display shows the exact amount of compressed air being used, making it easy to identify piping that may be undersized. Installing one on every major leg of your air distribution system to constantly monitor and benchmark compressed air usage is a fast and efficient way to see what your volume through that distribution leg is.
3). Over pressurization is also an issue, as the pressure is raised to account for high demand periods, system leaks and pressure drops. Unfortunately operating at higher pressures can require as much as 25 percent more compressor capacity than needed, generating wasted air which is called artificial demand.
You can reduce the leakage rate by running the compressor at lower pressures. If you’re short on air, don’t turn up the pressure. Run your compressor at no higher pressure than what you process requires. To relieve peak demands on your system consider the EXAIR Receiver Tank. It store’s compressed air during low usage times and releases it when the demand is increased without working your air compressor system harder.
4). Finally, a preventative maintenance (PM) program will need to be implemented to keep the air compressor system running properly. Two items that are often neglected are the drive belts and filters. Loose belts can reduce compressor efficiency and dirty filters allow dirt to get through the system and cause pressure drops. EXAIR has replacement elements for our line of filter separators to keep you air clean and line pressure down.
By increasing your awareness of the health of your air compressor system and implementing a PM program you can significantly reduce your costs from wasted energy and avoid costly down time from an out of service air compressor.
If you would like to discuss improving your compressed air efficiency or any of EXAIR’s engineered solutions, I would enjoy hearing from you…give me a call.
Keeping noise levels in check and at safe levels is very important to ensure employee safety and well being. OSHA (the Occupational Safety and Health Administration) through standard 29 CFR-1910.95(a) has studied the situation and set Maximum Allowable Noise Exposure limits in Hours per Day based on the Sound Level, in dBA, of exposure.
For existing processes, a Digital Sound Meter is a valuable tool to measure the sound level to ensure that the source of loud noises can be quickly identified and isolated for immediate corrective action.
For new processes, or changes to an existing process, it is important to estimate the sound level prior to installation and start-up, so that precautions can be taken as needed.
For example, let’s say we are going to add a blow off station to clean off a part on a conveyor to improve the process and increase the throughput. A typical set-up might be a 12″ Super Air Knife (model 110012) blowing off the top and a pair of Super Air Nozzles (model 1100) to blow off the sides.
If we look at the performance data for the (2) different blow off devices, we find that the Super Air Knife is rated at 69 dBA and the nozzles at 74 dBA, when operated at 80 PSIG of compressed air supply.
When asked, “what is the sound level for (1) of the knives, and (2) of the nozzles” a little Acoustic Engineering is in order. The decibel scale is logarithmic, and determining the total sound level when all (3) devices are in operation is not as easy as adding up the three sound level values (which would equal 218 dBA, way off the charts!). Thankfully, both the actual sound level and the numerical value are determined another way. I’ll spare you a lot of the math but the equation is as below.
… where SL1, SL2, SL3, … are the sound levels in dBA of the each sound makers, for as many that are being combined (in our example SL1 = 69, SL2 = 74 and SL3 = 74)
Plugging in the numbers into the equation, the combined sound level works out to be a quiet 77.65 dBA — well within the OSHA limit for exposure for a full 8 hour period.
It is important to know the cost of compressed air at your facility. Most people think that compressed air is free, but it is most certainly not. Because of the expense, compressed air is considered to be a fourth utility in manufacturing plants. In this blog, I will show you how to calculate the cost to make compressed air. Then you can use this information to determine the need for Intelligent Compressed Air® products.
There are two types of air compressors, positive displacement and dynamic. The core construction for both is an electric motor that spins a shaft. Positive displacement types use the energy from the motor and the shaft to change the volume in an area, like a piston in a reciprocating compressor or like rotors in a rotary compressor. The dynamic types use the energy from the motor and the shaft to create a velocity energy with an impeller. (You can read more about air compressors HERE). For electric motors, the power is described either in kilowatts (KW) or horsepower (hp). As a unit of conversion, there are 0.746 KW in 1 hp. The electric companies charge at a rate of kilowatt-hour (KWh). So, we can determine the energy cost to spin the electric motors. If your air compressor has a unit of horsepower, or hp, you can use Equation 1:
hp * 0.746 * hours * rate / (motor efficiency)
hp – horsepower of motor
0.746 – conversion to KW
hours – running time
rate – cost for electricity, KWh
motor efficiency – average for an electric motor is 95%.
If the air compressor motor is rated in kilowatts, or KW, then the above equation can become a little simpler, as seen in Equation 2:
KW * hours * rate / (motor efficiency)
KW – Kilowatts of motor
hours – running time
rate – cost for electricity, KWh
motor efficiency – average for an electric motor is 95%.
As an example, a manufacturing plant operates 250 day a year with 8-hour shifts. The cycle time for the air compressor is roughly 50% on and off. To calculate the hours of running time, we have 250 days at 8 hours/day with a 50% duty cycle, or 250 * 8 * 0.50 = 1,000 hours of running per year. The air compressor that they have is a 100 hp rotary screw. The electrical rate for this facility is at $0.08/KWh. With these factors, the annual cost can be calculated by Equation 1:
In both equations, you can substitute your information to see what you actually pay to make compressed air each year at your facility.
The type of air compressor can help in the amount of compressed air that can be produced by the electric motor. Generally, the production rate can be expressed in different ways, but I like to use cubic feet per minute per horsepower, or CFM/hp.
The positive displacement types have different values depending on how efficient the design. For a single-acting piston type air compressor, the amount of air is between 3.1 to 3.3 CFM/hp. So, if you have a 10 hp single-acting piston, you can produce between 31 to 33 CFM of compressed air. For a 10 hp double-acting piston type, it can produce roughly 4.7 to 5.0 CFM/hp. As you can see, the double-acting air compressor can produce more compressed air at the same horsepower.
The rotary screws are roughly 3.4 to 4.1 CFM/hp. While the dynamic type of air compressor is roughly 3.7 – 4.7 CFM/hr. If you know the type of air compressor that you have, you can calculate the amount of compressed air that you can produce per horsepower. As an average, EXAIR uses 4 CFM/hp of air compressor when speaking with customers who would like to know the general output of their compressor.
With this information, we can estimate the total cost to make compressed air as shown in Equation 3:
C = 1000 * Rate * 0.746 / (PR * 60)
C – Cost of compressed air ($ per 1000 cubic feet)
1000 – Scalar
Rate – cost of electricity (KWh)
0.746 – conversion hp to KW
PR – Production Rate (CFM/hp)
60 – conversion from minutes to hour
So, if we look at the average of 4 CFM/hp and an average electrical rate of $0.08/KWh, we can use Equation 3 to determine the average cost to make 1000 cubic feet of air.
Once you have established a cost for compressed air, then you can determine which areas to start saving money. One of the worst culprits for inefficient air use is open pipe blow-offs. This would include cheap air guns, drilled holes in pipes, and tubes. These are very inefficient for compressed air and can cost you a lot of money. I will share a comparison to a 1/8” NPT pipe to an EXAIR Mini Super Air Nozzle. (Reference below). As you can see, by just adding the EXAIR nozzle to the end of the pipe, the company was able to save $1,872 per year. That is some real savings.
Making compressed air is expensive, so why would you not use it as efficiently as you can. With the equations above, you can calculate how much you are paying. You can use this information to make informed decisions and to find the “low hanging fruit” for cost savings. As in the example above, targeting the blow-off systems in a facility is a fast and easy way to save money. If you need any help to try and find a way to be more efficient with your compressed air system, please contact an Application Engineer at EXAIR. We will be happy to assist you.
Our distributor in Peru recently contacted me with an application they were working on with a customer of theirs that deals in the mining industry. They are one of the largest gold mining companies in South America and were looking for a means of keeping their saw blades cool without having to use any type of coolant or water.
In this specific application, they had been using water to maintain the temperature of the blade while cutting. While this did work, it created quite a mess and also resulted in product contamination. The water on the floor presented a slipping hazard and production would have to periodically be halted so that someone could come by and clean the mess off of the floor. So, not only were they creating a contamination issue, but also a safety concern as well as lost production time.
Our distributor introduced them to EXAIR and our line of Cold Gun Spot Cooling Products. By replacing the water cooling with (2) Model 5230 Cold Gun systems, they were able to maintain the temperature of the blade at 24°C (75°F), well within their specifications. This allowed them to completely eliminate the need for water as a cooling method, improving their worker safety as well as increasing production.
EXAIR’s Cold Gun utilizes Vortex Tube technology to create two streams of air: one hot and one cold. The hot air is muffled and exhausted, while the cold air is also muffled and ducted to deliver a cold stream of air directly onto the material needing to be cooled. With only a supply of clean, dry compressed air required to operate, installation is quick and easy. Since the Cold Gun has no moving parts to wear out, there’s also no maintenance required so long as the Auto-Drain filter included in the kit is installed upstream of the Cold Gun.
If you’re tired of dealing with messy water-based cooling systems or equally messy coolants, give an Application Engineer a call today and try out a Cold Gun. With our Unconditional 30 Day Guarantee, there’s absolutely no risk to do so!