Super Air Knives Save 63% Electrical Cost for a Food Manufacturer Drying Trays

A food manufacturing company was looking for a more efficient way to dry polypropylene trays that were filled with food product. With their current operation, they would send already packed and sealed food trays through a washing system that used sterilized water. The trays would then have to be dried prior to bulk packaging. The operators would place the trays side by side on a 24” wide open-mesh stainless steel metal conveyor with two or three trays at a time (depending on the tray dimensions). They contacted EXAIR because they wanted to replace their “old and inefficient system” with something better.

In my discussions, they gave some additional details of the operation and the problems that they were seeing. The dimensions of the trays ranged from 150 to 200mm long by 100 to 150mm wide by 35 to 50mm in height. They were cleaning at a rate of 30 trays per minute through the washing and drying system. The washer was designed to recycle the water to improve “green” operations. But the trays were carrying much of the water outside the machine. Thus, they would have to stop and refill the wash system with fresh water.

After the washing cycle, the drying section began. It consisted of two parts; a sponge roller and a heated chamber that would blow hot air. First the trays would run under the sponge roller to absorb the water from the top of the trays. A feature that they did not like was the continuous adjustment to the sponge roller for the different tray heights. They had to make sure that they had good contact without stopping the movement.

Also, with bulk of the water being on top of the trays, the sponge surface would get saturated. They would have to stop the process to change with a dry foam pad or replace due to wear. After the sponge roller, it would move into a heated chamber to remove the remaining portion of the water from the trays. They used a 11 KW heating system to blow hot air. This part of their system required a lot of electricity to run. They wondered if EXAIR could help streamline their process and reduce energy costs.

They sent a photo of their system, reference above. As described, the trays were moving intermittently through the wash cycle and then into the drying operation. When gaps are present in a process, the Electronic Flow Control, or EFC, becomes a great product for energy efficiency. It is designed to use a photoelectric sensor to detect a part and initiate a timing sequence. Using a solenoid valve, it will turn on the compressed air only when needed. With the drying operation, I suggested that they could remove the sponge roller and heated chamber, and replace them with two Super Air Knives. In conjunction with the EFC, we can decrease energy usage, reduce downtime, and increase savings. Profit margins can be critical in the food industry, and EXAIR has many ways to help.

Electronic Flow Control

To expand a bit more about revitalizing the “old and inefficient system” with EXAIR products, I made some suggestions. I recommended two Stainless Steel Super Air Knife Kits, model 110224SS, to be placed near the end of the conveyor. One Super Air Knife would be positioned above the tray to blow across the top; and one would be positioned below the tray under the mesh conveyor to blow across the bottom.

At a slight blowing angle in a counter-flow direction, the air streams would remove the water from the top and bottom of the tray at the same time. This would create a non-contact “wiping” solution. Now they do not have to worry about parts wearing out due to contact. Another unique feature of the Super Air Knife is the strength of the laminar air stream. It is consistent from 3” (76mm) to 12” (305mm) away from the target. Thus, they can easily set the height of the Super Air Knives to dry all the different trays without adjusting it.

And as an added benefit, the water that was being blown off the trays by the Super Air Knives remained within the washing system. The sterilized water was not being wasted and could be recycled. With the Electronic Flow Control, I recommended the model 9056. It is a user-friendly device with eight different timing sequences. They were able to position the photoelectric sensor near the outlet of the washing system. As soon as the trays were detected, the Super Air Knives would turn on to blow two or three trays at the same time. With the EXAIR products installed, the system went from using 11 KW down to 4 KW, a 63% savings.

EXAIR has helped many customers like this one above. When it comes to energy savings, EXAIR leads the way. With two Super Air Knives and an EFC, we were able to modernized their system; save on water, improve productivity, reduce the overall footprint, and save on their energy usage. If you have a similar application, you can contact an Application Engineer at EXAIR. We will be happy to update your system.

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

EXAIR Standard Air Knife Keeps Bottles Free From Contaminants

Recently I worked with a customer on an application to remove contaminants from the inside of glass bottles. During production, dust from the ambient environment was collecting inside of the bottles. They needed a way to remove it prior to filling. The solution was to briefly pause the conveyor, pulsing air into the bottles to free any dust that had accumulated. Their problem was that while the dust was blowing out of the bottle without an issue, some of it was settling back down into the bottles.

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The customer needed a way to mitigate the risk of dust particles resettling into the bottles after it was removed. The solution was to install a Model 2012 12” Standard Air Knife to provide a curtain of air across the top of the bottles, catching any freed dust particles and blowing them away from the conveyor.

After noticing positive results, we wanted to take things one step further and help to reduce overall air consumption in the process. The blowoff was achieved with (8) ¼” open tubes operating at a pressure of 80 PSIG. Although they were only operating for a fraction of a second, they still consume a whopping 33 SCFM! Replacing them with Model 1101 ¼” NPT Super Air Nozzles (14 SCFM at 80 PSIG) resulted in compressed air savings of 58%!!

In addition to saving compressed air, the noise level was also dramatically reduced. At just 74 dBA, we’re below the threshold for an 8-hour exposure time for operators according to OSHA. Where earplugs were necessary before, they’re now able to operate safely without the need for PPE to protect their hearing. The second most effective fundamental method of protecting workers, according to NIOSH, is to substitute or replace the hazard with an engineered solution. It’s not possible to eliminate the hazard as a compressed air blowoff was necessary, but the next best step is to replace it with something safer.

HierarchyControls

In addition to complying with OSHA 1910.95(a), the Super Air Nozzle also cannot be dead-ended. In applications for compressed air blowoff with unsafe nozzles, pipes, or tubes, the pressure must be regulated down to below 30 PSIG according to OSHA 1910.242(b). The installation of an engineered compressed air nozzle by EXAIR allows you to operate safely at much higher pressures.

If you have inefficient blowoff processes in your facility, give one of our Application Engineers a call. We’ll be happy to take a closer look at your application and recommend a safe, reliable, engineered solution!

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

Compressed Air Efficiency – How It Benefits Business

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 here in the Midwest is .25 cents per 1,000 Standard Cubic Feet, that translates into .075 cents for every .25 cents spent!  Compounded with the fact that energy costs have doubled in the last five years, it couldn’t be a better time to make your air compressor system more efficient.

efficiencylab

The following steps will help you save air and in turn save money.

  1. Measure the air consumption to find sources that use a lot of compressed air.

Knowing where you stand with your compressed air demand is important to be able to quantify the savings once you begin to implement a compressed air optimization program. Placing a value upon your compressed air consumption will also allow you to place a value on its costs and the savings you will reap once you start to reduce your consumption. (EXAIR’s Digital Flow Meter)

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  1. Find and fix the leaks in your compressed air system.

Not fixing your compressed air system leaks can cause your system pressure to fluctuate and affect your equipment negatively. It may cause you to run a larger compressor than necessary for your compressed air needs and raise your total costs. Or it could cause your cycle and run times to increase which leads to increased maintenance to the entire system. (EXAIR’s Ultrasonic Leak Detector)

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  1. Upgrade your blow off, cooling and drying operations using engineered compressed air products.

Your ordinary nozzle with a through hole and a cross drilled hole can be an easy choice based upon price, but if you do not consider the operating cost you do not really know how much it is costing you. An Engineered Air Nozzle will pay for itself and lower operating costs quickly. Engineered Air Nozzles are the future of compressed air efficiency and are made to replace ordinary nozzles, homemade nozzles and open line blow offs. Engineered Nozzles reduce air consumption and noise levels; ordinary nozzles cannot compete. Engineered Nozzles maintain safety features and can qualify for an energy savings rebate from a local utility; ordinary nozzles fall short. Open blow off or homemade blow off applications typically violate OSHA safety standards; Engineered Nozzles do not.  (EXAIR’s Air Nozzles)

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EXAIR Nozzles
  1. Turn off the compressed air when it is not in use.

Automated solutions add solenoid valves and run them from your machine controls. If the machine is off, or the conveyor has stopped – close the solenoid valve and save the air.  And blow off applications can benefit from any space in between parts by turning the air off during the gaps with the aid of a sensor and solenoid. (EXAIR’s automated  Electronic Flow Control)

 

  1. Use intermediate storage of compressed air near the point of use.

Also known as secondary receivers, intermediate air storage is especially effective when a system has shifting demands or large volume use in a specific area. Intermediate storage is the buffer between a large demand event and the output of your compressor. The buffer created by intermediate storage (secondary receiver) prevents pressure fluctuations which may impact other end use operations and affect your end product quality. (EXAIR’s Receiver Tanks)

  1. Control the air pressure at the point of use to minimize air consumption.

This is a very simple and easy process, all it requires is a pressure regulator. Installing a pressure regulator at all of your point of use applications will allow you to lower the pressure of these applications to the lowest pressure possible for success. Lowering the pressure of the application also lowers the air consumption. And it naturally follows that lower air consumption equals energy savings. (EXAIR’s Pressure Regulators)

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.

Jordan Shouse
Application Engineer
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Twitter: @EXAIR_JS

 

 

Compressed Air – The Fourth Utility

Industrial use of compressed air dates to the middle of the 19th century.  European engineers developed & used compressed air operated drills in the construction of the Mont Cenis Tunnel in 1861.  This type of machinery had typically been steam-powered, but you needed a fire to boil the water.  Since steam loses energy when piped over long distances, that means you’d need a fire in the tunnel shaft, and that’s not good for the miners.  Electric powered products were not a viable option…they weren’t developed to the scale needed for this, and generation & distribution were not up to the task back then.

Compressed air made the most sense, because it COULD be generated locally, outside the shaft, and plumbed in to the tools without energy loss (much of the energy from steam is lost when it condenses…and compressed air doesn’t condense.)  The Mont Cenis Tunnel project was a big deal in the advancement of industrial compressed air applications.  It was originally estimated to take 25 years, but, largely due to the success of the air operated drills, it was completed in only 14 years.  This got the attention of mining industry folks in America, where coal mining was growing exponentially in the late 1800’s.

The need for bigger & better machinery and tools kept pace with the growth in industry overall throughout this time, and even to the present day.  As the distribution grid spread to just about everywhere, electricity became the principal method of providing power.  Natural gas remains popular for especially large machinery, heating, and, in fact, for electric power generation.

Water has always been key to just about any human endeavor, from agriculture, to chemical production, to cleaning…which is universal to any industry.  Like electricity and natural gas, its distribution grid was also vital to industrial growth & production.

As the “fourth utility,” as it’s become known, compressed air is unique in that it’s customarily generated on site.  This gives control to the consumer, which is great, because they can decide how much they want to make, based on how much they want to use.  And, because many applications that can use compressed air can also be addressed through other means (more on that in a minute,) the powers-that-be can decide which one makes the most sense, big-picture-wise.

Here are some common industrial applications that can be handled pneumatically, or otherwise:

  • EXAIR is the industry leader in point-of-use compressed air product applications. Try us, you’ll see.

    Moving product from one place to another: air operated conveyors (like EXAIR Line Vacs) or electric powered belt/auger/bucket conveyors.

  • Force and motion: pneumatic, or hydraulic cylinders.
  • Cleaning: Compressed air blow off devices (like EXAIR Intelligent Compressed Air Products) or electric powered blowers…or brooms, brushes, and dustpans.
  • Rotary or impact tools: pneumatic or electric.
  • Cooling: Compressed air operated Vortex Tubes, or refrigerant based chillers, or chilled water.

The fact that there are four major utilities proves that there’s usually more than one solution to an application.  The challenge is, which one makes the most sense?  If you need help with data or recommendations from a compressed air industry expert, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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Supply Side Review: Heat of Compression-Type Dryers

The supply side of a compressed air system has many critical parts that factor in to how well the system operates and how easily it can be maintained.   Dryers for the compressed air play a key role within the supply side are available in many form factors and fitments.  Today we will discuss heat of compression-type dryers.

Heat of compression-type dryer- Twin Tower Version

Heat of compression-type dryers are a regenerative desiccant dryer that take the heat from the act of compression to regenerate the desiccant.  By using this cycle they are grouped as a heat reactivated dryer rather than membrane technology, deliquescent type, or refrigerant type dryers.   They are also manufactured into two separate types.

The single vessel-type heat of compression-type dryer offers a no cycling action in order to provide continuous drying of throughput air.  The drying process is performed within a single pressure vessel with a rotating desiccant drum.  The vessel is divided into two air streams, one is a portion of air taken straight off the hot air exhaust from the air compressor which is used to provide the heat to dry the desiccant. The second air stream is the remainder of the air compressor output after it has been processed through the after-cooler. This same air stream passes through the drying section within the rotating desiccant drum where the air is then dried.  The hot air stream that was used for regeneration passes through a cooler just before it gets reintroduced to the main air stream all before entering the desiccant bed.  The air exits from the desiccant bed and is passed on to the next point in the supply side before distribution to the demand side of the system.

The  twin tower heat of compression-type dryer operates on the same theory and has a slightly different process.  This system divides the air process into two separate towers.  There is a saturated tower (vessel) that holds all of the desiccant.  This desiccant is regenerated by all of the hot air leaving the compressor discharge.  The total flow of compressed air then flows through an after-cooler before entering the second tower (vessel) which dries the air and then passes the air flow to the next stage within the supply side to then be distributed to the demand side of the system.

The heat of compression-type dryers do require a large amount of heat and escalated temperatures in order to successfully perform the regeneration of the desiccant.  Due to this they are mainly observed being used on systems which are based on a lubricant-free rotary screw compressor or a centrifugal compressor.

No matter the type of dryer your system has in place, EXAIR still recommends to place a redundant point of use filter on the demand side of the system.  This helps to reduce contamination from piping, collection during dryer down time, and acts as a fail safe to protect your process.  If you would like to discuss supply side or demand side factors of your compressed air system please contact us.

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF

 

Heat of compression image: Compressed Air Challenge: Drive down your energy costs with heat of compression recovery: https://www.plantservices.com/articles/2013/03-heat-of-compression-recovery/

 

How to Size a Receiver Tank and Improve your Compressed Air System

Receiver Tank: Model 9500-60

My colleague, Lee Evans, wrote a blog about calculating the size of primary receiver tanks within a compressed air system.  (You can read it here: Receiver Tank Principle and Calculations).  I would like to expand a bit more about secondary receiver tanks.  They can be strategically placed throughout the plant to improve your compressed air system.  The primary receiver tanks help to protect the supply side when demands are high, and the secondary receiver tanks help systems on the demand side to optimize performance.

Circuit Board

I like to compare the pneumatic system to an electrical system.  The receiver tanks are like capacitors.  They store energy produced by an air compressor like a capacitor stores energy from an electrical source.  If you have ever seen an electrical circuit board, you notice many capacitors with different sizes throughout the circuit board (reference photo above).  The reason is to have a ready source of energy to increase efficiency and speed for the ebbs and flows of electrical signals.  The same can be said for the secondary receiver tanks in a pneumatic system.

To tie this to a compressed air system, if you have an area that requires a high volume of compressed air intermittently, a secondary receiver tank would benefit this system.  There are valves, cylinders, actuators, and pneumatic controls which turn on and off.  And in most situations, very quickly.  To maximize speed and efficiency, it is important to have a ready source of air nearby to supply the necessary amount quickly.

For calculating a minimum volume size for your secondary receiver tank, we can use Equation 1 below.  It is the same as sizing a primary receiver tank, but the scalars are slightly different.  The secondary receivers are located to run a certain machine or area.  The supply line to this tank will typically come from a header pipe that supplies the entire facility.  Generally, it is smaller in diameter; so, we have to look at the air supply that it 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.  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 smallest volume that would be needed.  The other value 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.  So, any larger volume would fit the requirement as a secondary receiver tank.

Secondary Receiver tank capacity formula (Equation 1)

V = T * (C – Cap) * (Pa) / (P1-P2)

Where:

V – Volume of receiver tank (cubic feet)

T – Time interval (minutes)

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

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

Pa – Absolute atmospheric pressure (PSIA)

P1 – Header Pressure (PSIG)

P2 – Regulated Pressure (PSIG)

If you find that your pneumatic devices are lacking in performance because the air pressure seems to drop during operation, you may need to add a secondary receiver to that system.  For any intermittent design, the tank can store that energy like a capacitor to optimize the performance.  EXAIR stocks 60 Gallon tanks, model 9500-60 to add to those specific locations, If you have any questions about using a receiver tank in your application, primary or secondary, you can contact an EXAIR Application Engineer.  We can restore that efficiency and speed back into your application.

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

 

Photo: Circuit Board courtesy from T_Tide under Pixabay License

Six Steps to Optimization, Step 4 – Turn Off Your Compressed Air When Not in Use

Step 4 of the Six Steps To Optimizing Your Compressed Air System is ‘Turn off the compressed air when it isn’t in use.’  Click on the link above for a good summary of the all the steps.

6 Steps from Catalog

Two basic methods to set up a compressed air operation for turning off is the ball valve and the solenoid valve. Of the two, the simplest is the ball valve. It is a quarter turn, manually operated valve that stops the flow of the compressed air when the handle is rotated 90°. It is best for operations where the compressed air is needed for a long duration, and shut off is infrequent, such as at the end of the shift.

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Manual Ball Valves, from 1/4 NPT to 1-1/4 NPT

The solenoid valve offers more flexibility. A solenoid valve is an electro-mechanical valve that uses electric current to produce a magnetic field which moves a mechanism to control the flow of air. A solenoid can be wired to simple push button station, for turning the air flow on and off – similar to the manual valve in that relies on a person to remember to turn the air off when not needed.

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A Wide Array of Solenoid Valve Offerings for Various Flows and Voltage Requirements

Another way to use a solenoid valve is to wire it in conjunction with a PLC or machine control system. Through simple programming, the solenoid can be set to turn on/off whenever certain parameters are met. An example would be to energize the solenoid to supply an air knife when a conveyor is running to blow off parts when they pass under. When the conveyor is stopped, the solenoid would close and the air would stop blowing.

The EXAIR EFC (Electronic Flow Control) is a stand alone solenoid control system. The EFC combines a photoelectric sensor with a timer control that turns the air on and off based on the presence (or lack of presence) of an object in front of the sensor. There are 8 programmable on/off modes for different process requirements. The use of the EFC provides the highest level of compressed air usage control. The air is turned on only when an object is present and turned off when the object has passed by.

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EFC Used To Control Bin Blow Off Operation

By turning off the air when not needed, whether by a manual ball valve, a solenoid valve integrated into the PLC machine control or the EXAIR EFC, compressed air usage will be minimized and operation costs reduced.

If you have questions about the EFC, solenoid valves, ball valves or any of the 15 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.

Brian Bergmann
Application Engineer
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