Compressed Air Knives vs. Blower Air Knives, an Application Comparison

A company was needing to dry vegetables after a washing system.  They currently had three blower air knives (as shown in the photo above) to remove the water before packaging.  The issues that they presented to me were in two parts.  They were not able to generate enough force to remove enough water from larger products like cauliflower and broccoli.  And, the heat from the blower system was affecting the appearance of the thinner vegetables like snow peas.  They purchased the blower-style air knives under the belief that they would save money by not using compressed air.  They found out quickly that it was not a true statement especially when it comes to the total cost of ownership.

Super Air Knife drying fruits and vegetables

When comparing the EXAIR Super Air Knife to a blower-type air knife, there are many features that should be reviewed.  For the customer above, they used an 18” (457mm) wide conveying system to wash more than twenty different fruits and vegetables.  So, they needed versatility to dry the different types of products.  With the Super Air Knife, we have a simple way to adjust the force by changing the inlet air pressure.  So, we can blow air at a light breeze for the snow peas to a very strong force to dry the cauliflower and broccoli.  With the engineered design of the Super Air Knife, we can achieve a 40:1 amplification ratio.  That means for every 1 part of compressed air, we are able to entrain 40 parts of ambient air.  This unique feature allows for the Super Air Knife to be very efficient with your compressed air as well as keeping the blowing air at ambient temperatures.  The design of a blower system allows the air to become hot, turbulent, and limited in force.  As noted in the photo above, they had to use three blower knives to try to remove the liquid water.  With the Super Air Knife, I recommended just one air knife to do the job.  They decided to try an EXAIR model 110218SS 18″ Stainless Steel Super Air Knife Kit to see if their concept of “saving money” with the blower-type air knife was valid.

To better explain the concept, I divided the comparisons into different categories.  You can decide if the Super Air Knife would be a better product than the blower-type air knife.  It sure was for the customer above.

  1. Initial Cost:
    1. Blower System – They are an expensive product when you have to include a blower, ducting, and a knife. To have any flexibility, a control panel with a VFD will be needed.  A capital expenditure is typical for a complete system.
    2. Super Air Knife – It is a fraction of the cost. With their system above, we were roughly 1/10 the cost.  A capital expense would not be required for ordering a Super Air Knife to remove the water.
  2. Maintenance:
    1. Blower System – The intake filter has to be changed periodically as well as the motor and belt has to be checked as a preventive maintenance. Being that the blower motor is a mechanical device, the bearings and belts will wear and have to be replaced.  Without proper maintenance, things can break prematurely.  Loss of production will cost you much money.
    2. Super Air Knife – They do not have any moving parts to wear out. Only compressed air is needed to operate.  The maintenance requirement is to change the compressed air filter once a year.
  3. Compressed air usage:
    1. Blower System – This device does not need any compressed air to work, but it does use an electric motor. For this customer, they had a 7.5KW blower motor.  With the inherent design of blower-type air knives, they have a reduced blowing force and turbulent air flow.  This combination required the maximum power output on the 7.5KW blower motor.
    2. Super Air Knife –With their unique design, it has one of the highest efficiencies in the market place. It can entrain 40 parts of ambient “free” air with every 1 part of compressed air.  With laminar flow and the power of compressed air, the Super Air Knives can be used at a much lower air pressure.  To compare with the electric blower motor above, the Super Air Knives would use 10KW of compressor power to operate at the highest force rating.  So, at lower air pressures, the blower motor and compressor requirement will be very similar.
  4. Noise:
    1. Blower System – With the turbulent air flow, the blower units are very loud. If operators are working near the system, they would need PPE for hearing protection, or elect to purchase (for even more money) a sound enclosure which some of the blower manufacturers offer.
    2. Super Air Knife – These units are very quiet. Even at a higher pressure, the sound level is only 72 dBA at 100 PSIG (6.9 Bar).  This level is well below the maximum noise exposure for hearing safety as marked in OSHA 29CFR 1910.95(a).
  5. Installation:
    1. Blower System –Just to begin, the installers will have to run electrical wires, controls, and ducting. The foot print is large and will need space to install.  They will have to drill holes in the floor to hold the blower in place, and perhaps build an attenuation chamber.  This can take days with no production to start operating.  And time is money.
    2. Super Air Knife –They are compact and do not take up much space. They mount easily into a system.  You can run a plastic tube or rubber hose to the Super Air Knife from a compressed air source.  If you use the Universal Mounting Kit, they will only need a 1/2″ hole for attaching.  Even if a fabricator has to make a bracket to fit into their system, the timing is in hours not days.
  6. Heat:
    1. Blower System – Besides being quite loud, blower systems get very hot as a function of the operation. While this may be sold as a benefit for some applications, it is considered a significant drawback for drying fruits and vegetables. The air can reach a target temperature of 180°F (82°C).
    2. Super Air Knife – The advantage for the Super Air Knife is the amplification ratio. The total volume of air that comes from it is 40 parts ambient and 1 part compressed air. So, the temperature of the airflow is going to be the same as the ambient environment surrounding the Super Air Knife.

The total cost of ownership is quite clear when you look at loss of output, loss of product, and breakdown of equipment.  After reviewing the information above, it was easy for them to try the model 110218SS Stainless Steel Super Air Knife Kit.  When they replaced the blower-type air knives, the customer did share some information with me.

First, they were amazed at the ease of installation and the compact design.  The customer also mentioned the amount of force that could be created by the Super Air Knife.  They were able to increase and decrease the required force to remove the liquid water from all the different fruits and vegetables.  This gave them the flexibility that they were looking for in their process.  And of course, the maintenance time and cost were eliminated.

Compressed air can be expensive, but if you use EXAIR products, you can use the compressed air very efficiently.  You do not have to sacrifice other areas within the total cost of ownership.  If you have a similar application, you can contact an Application Engineer at EXAIR.  We will be happy to discuss the benefits of using the EXAIR Super Air Knives over a blower-type air knife.

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

EXAIR External Mix Atomizing Nozzles – For Use with Viscous Fluids and High Flow Rates

EXAIR’s Atomizing Spray Nozzles are used to atomize fluids in a wide range of different spray patterns. They utilize a small amount of compressed air which mixes with the liquid supply to create a fine mist of atomized liquid. EXAIR manufactures Atomizing Spray Nozzles in (3) different varieties: Internal Mix, External Mix, and Siphon Fed. For this blog, I’m going to focus on just the External Mix variety.

extmixeffam

On all External Mix Atomizing Nozzles the volume of liquid is easily adjusted by adjusting the valve stem on the standard Atomizing Nozzle, or by regulating the liquid pressure (the only option with the No-Drip style). Increasing the liquid pressure will result in an increased liquid flow rate.

The External Mix nozzles have the highest flow rates and can be used with liquids with a viscosity greater than 300 centipoise (cP). Since the air and liquid are mixing just outside of the nozzle, thicker liquids have a lesser chance of clogging in the nozzle. Both the liquid stream and the air stream will come into contact with each other just outside both the air and liquid caps. The compressed air breaks the liquid up into very small particles, allowing you to use much less liquid than a liquid only nozzle.

This makes them very effective in applications that utilize expensive paints, oils, or other liquids. Rather than wasting the expensive materials, the nozzle can be set to precisely dispense only what is necessary to achieve a successful application. The External Mix Atomizing Nozzle is available in the standard configuration as well as the No-Drip style.

The No-Drip Atomizing Nozzle is used in a variety of applications where any liquid dripping from the nozzle after the air supply has shut off would cause a problem. This is common in painting applications where any paint dripping would affect the quality.

EB_wineALTFT

The External Mix Atomizing Nozzle is available in (3) different sizes: 1/8” NPT, ¼” NPT, and ½” NPT. If your application could benefit from utilizing the fine atomized spray of liquid look no further than EXAIR’s Atomizing Nozzles. With all sizes and configurations available from stock, we can get one out to you quickly!

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

 

Adjustable Air Amplifier Transfers Plastic Bag Scrap

Many times EXAIR products are used to help sort materials based on their weight or their density by providing a consistent force against a series of targets that should be of the same density or weight, but when they are not, the airflow can be “tuned” to remove the non-conforming parts.

aal-vacuum
Model 6042 Aluminum Adjustable Air Amplifier rejects empty pouches.

In this case, our customer (a packaging automation specialist) was working with a form fill and seal machine that was dedicated to making pouches 2” x 8” and filling them with a food product. In some cases, the pouches would not become filled with product and needed to be removed from the line. So, our customer devised a way to mount model 6042 2” Adjustable Air Amplifier along-side the travel of the pouches and set the input pressure and air gap setting to get optimum vacuum capture velocity to suck away empty ones and leave the full ones in-tact. Above you can see a photo that the customer took while mocking up the application at their facility. You can see the hose connected to the output to direct the empty pouches to a wire basket below.

A couple of things in this application made use of the Adjustable Air Amplifier the best choice. The first was the funnel-shaped suction area on the back side of the Adjustable Air Amplifier. This optimizes the Air Amplifier’s ability to draw in ambient air to propel it to the outlet. In doing this the un-filled, light-weight, plastic pouch becomes caught in the high velocity stream and thus gets carried away as desired. The second thing is that since compressed air is the source of power, the customer has infinite adjustability over the amount of suction force that they can apply to the pouch in the application. They can adjust the air gap opening on the Adjustable Air Amplifier to have a coarse adjustment of air consumption as well as vacuum level. Then, they have a finer adjustment that a pressure regulator can provide to really dial in the suction force as they need it to be for removal of the empties.

The idea here is that while Air Amplifiers are generally used for their output flow to cool targets and provide a significant Blowoff force, they can also be used to draw in not only smoke and fumes but also other lightweight items like the empty pouches above.

If you have a need to set up any kind of sorting process, maybe just to separate two different recycling streams or perhaps it is a need to perform a quality control function as shown above, think about EXAIR and our many solutions in this area.

Neal Raker, International Sales Manager
nealraker@exair.com
@EXAIR_NR

EXAIR Cabinet Coolers vs. Air to Air Heat Exchangers

At EXAIR we’ve been providing enclosure cooling solutions for decades, and in many cases those cooling solutions have remained in place for decades as well.  In the time we’ve been in the market with industrial enclosure cooling solutions we’ve encountered a number of alternative means for enclosure cooling.  One of those methods is an air-to-air heat exchanger.

heat exchanger 1
Heat exchanger

An air-to-air heat exchanger uses the temperature differential between the ambient air surrounding an enclosure and the hot air inside an enclosure to create a cooling effect.  A closed loop system exchanges the heat inside the enclosure with the outside air in an effort to maintain a set internal temperature.  The heat exchange of most air-to-air unit relies on a heat pipe, a heat-transfer device which converts an internal refrigerant liquid into vapor by placing one end of the pipe in contact with the hot environment.  The heated vapor travels to the other end of the pipe which is in contact with a cooler environment.  The vapor condenses back into a liquid (releasing latent heat) and returning to the hot end of the pipe and the cycle repeats.

But, this type of a solution does give some cause for concern, especially when considering their use in an industrial environment.  Here are the key points to keep in mind when comparing an air-to-air cooler to an EXAIR Cabinet Cooler.

Cabinet Cooler Family
EXAIR Cabinet Coolers

Required temperature differential based on ambient air temp

An air-to-air heat exchange relies on the ΔT between the ambient air temperature and the internal enclosure air temperature to produce cooling.  If this ΔT is low, or the ambient temperature rises, cooling is diminished.  This means that as the temperatures in your facility begin to rise, air-to-air heat exchangers become less and less effective.  Larger air-to-air heat exchangers can be used, but these may be even larger than the enclosure itself.

EXAIR Cabinet Coolers rely on the ΔT between the cold air temperature from the Cabinet Cooler (normally ~20°F) and the desired internal enclosure temperature (normally 95°F).  The cold air temperature from the Cabinet Cooler is unaffected by increases in ambient temperatures.  The large ΔT and high volume cold air flow produced by a Cabinet Cooler results in more cooling capacity.  And, we can increase cooling capacity from a Cabinet Cooler without increasing its physical footprint, which is already much, much smaller than an air-to-air type of unit.

 

Cooling in high temperature environments

Due to their nature of operation, an air-to-air heat exchanger must have an ambient temperature which is lower than the desired internal temperature of the enclosure.  If the ambient air has a higher temperature, air-to-air units provide zero cooling.

Cabinet Coolers, on the other hand, can be used in hot, high temperature environments up to 200°F (93°C).

EXAIR's High Temp Cabinet Cooler Systems
High temperature Cabinet Coolers

 

Cooling in dirty environments

Dirt in the ambient environment will impact cooling performance with an air-to-air heat exchanger.  In order for the air-to-air unit to effectively remove heat, the heat pipe must have access to ambient air.  With any exposure to the ambient environment comes the possibility for the ambient end of the heat pipe to become covered in ambient contaminants such as dust.  This dust will create an insulation barrier between the heat pipe and the ambient air, decreasing the ability for the heat pipe to condense the vapors within.  Because of this, most air-to-air devices use filters to separate the heat pipe from the ambient environment.  But, when these filters become clogged, access to ambient temperatures are reduced, and cooling capacity of the air-to-air unit reduces as well.

Cabinet Coolers have no problem operating in dirty environments.  In fact, it is one of their strengths.  Without any moving parts to wear out or any need to contact ambient air for cooling purposes, a dirty environment poses no problems.  In fact, check out this blog post (and this one) about EXAIR Cabinet Coolers operating maintenance free for years in dirty environments.

exair-cabinet-cooler-03-2002-2008
NEMA 12 Cabinet Cooler in a Dirty Environment

Size and time required to install

Air-to-air heat exchangers vary in size, but even the smallest units can have large dimensions.  Many applications have limited space on the enclosure, and a large, bulky solution can be prohibitive.  Couple this with the time and modification required to the enclosure to install a large air-to-air unit, and the “solution” may end up bringing additional problems.

Another key aspect of the Cabinet Cooler is its size.  Small, compact, and easy to mount on the top or side of an enclosure, Cabinet Coolers install in minutes to remove overheating problems.

 

Heat within an electrical cabinet can be a major issue for manufacturing companies. The costs associated with down time and repairs on sensitive electronics that fail due to heat or environmental contaminants, are an unnecessary burden. If you have any questions about how an EXAIR Cabinet Cooler can solve problems in your facility, contact an EXAIR Application Engineer.

Jordan Shouse
Application Engineer
Send me an email
Find us on the Web 
Like us on Facebook
Twitter: @EXAIR_JS

HEPA Vac Improves Cleaning Process AND Keeps Operators Safe!

On a recent visit with our Hungarian Distributor, I had the pleasure of visiting an automotive leather manufacturing plant. They process and cut to order a wide variety of different styles of leather used in the manufacturing of European automobiles. In one of their machines, a grinding process is performed that smooths out the cut edges of the material before they’re stitched together.

The grinding process itself is self-contained within the machine, but the significant amount of leather dust created needs to be periodically cleaned out. If not, it ends up accumulating on some of the internal components and increasing the downtime and maintenance required on the machine. Due to this, they implemented a 2x per shift cleaning operation.

The machine has several tight spaces inside where the dust accumulates. They’d shut off the machine and blow out the dust. Then, sweep up all of the dust into a dustpan and dump it in the trash. This entire process took approximately 30 minutes each time for 1-hr/shift. With three shifts operating 24/7, that’s 3-hrs/day of lost production time for this particular cleaning process, still less than what they were experiencing as a result of the machine downtime when they weren’t regularly cleaning it.

HDHEPAVac559

However, the primary concern of theirs was that they were now blowing dust all over the shop causing a potential health hazard to their operators. They wanted a solution that would allow them to clean the machine, without presenting an additional hazard. We tested with a Mini Chip Vac first, but the dust was a bit too fine and was still passing through the filter bag.

For fine dusts such as this, the Heavy Duty HEPA Vac is the more suitable option. After testing the Heavy Duty HEPA Vac, it was clear that this was the solution they were hoping for. The high-powered vacuum made quick work of the dust inside, while keeping it contained inside of the drum by the HEPA filter.

They still need to stop and clean the machine out 2x/shift, but now the process only took 10 minutes. They reduced their overall downtime on this machine per day by 2/3 to just 1hr, while keeping their operators safe. While this wasn’t the reason for looking at new solutions, it was definitely an added benefit. If you’re looking for a maintenance-free vacuum system for cleaning up in your facility, EXAIR has a wide range of Industrial Housekeeping solutions available from stock.

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

Opportunities To Save On Compressed Air

If you’re a regular reader of the EXAIR blog, you’re likely familiar with our:

EXAIR Six Steps To Optimizing Your Compressed Air System

This guideline is as comprehensive as you want it to be.  It’s been applied, in small & large facilities, as the framework for a formal set of procedures, followed in order, with the goal of large scale reductions in the costs associated with the operation of compressed air systems…and it works like a charm.  Others have “stepped” in and out, knowing already where some of their larger problems were – if you can actually hear or see evidence of leaks, your first step doesn’t necessarily have to be the installation of a Digital Flowmeter.

Here are some ways you may be able to “step” in and out to realize opportunities for savings on your use of compressed air:

  • Power:  I’m not saying you need to run out & buy a new compressor, but if yours is
    Recent advances have made significant improvements in efficiency.

    aging, requires more frequent maintenance, doesn’t have any particular energy efficiency ratings, etc…you might need to run out & buy a new compressor.  Or at least consult with a reputable air compressor dealer about power consumption.  You might not need to replace the whole compressor system if it can be retrofitted with more efficient controls.

  • Pressure: Not every use of your compressed air requires full header pressure.  In fact, sometimes it’s downright detrimental for the pressure to be too high.  Depending on the layout of your compressed air supply lines, your header pressure may be set a little higher than the load with the highest required pressure, and that’s OK.  If it’s significantly higher, intermediate storage (like EXAIR’s Model 9500-60 Receiver Tank, shown on the right) may be worth looking into.  Keep in mind, every 2psi increase in your header pressure means a 1% increase (approximately) in electric cost for your compressor operation.  Higher than needed pressures also increase wear and tear on pneumatic tools, and increase the chances of leaks developing.
  • Consumption:  Much like newer technologies in compressor design contribute to higher efficiency & lower electric power consumption, engineered compressed air products will use much less air than other methods.  A 1/4″ copper tube is more than capable of blowing chips & debris away from a machine tool chuck, but it’s going to use as much as 33 SCFM.  A Model 1100 Super Air Nozzle (shown on the right) can do the same job and use only 14 SCFM.  This one was installed directly on to the end of the copper tube, quickly and easily, with a compression fitting.
  • Leaks: These are part of your consumption, whether you like it or not.  And you shouldn’t like it, because they’re not doing anything for you, AND they’re costing you money.  Fix all the leaks you can…and you can fix them all.  Our Model 9061 Ultrasonic Leak Detector (right) can be critical to your efforts in finding these leaks, wherever they may be.
  • Pressure, part 2: Not every use of your compressed air requires full header pressure (seems I’ve heard that before?)  Controlling the pressure required for individual applications, at the point of use, keeps your header pressure where it needs to be.  All EXAIR Intelligent Compressed Air Product Kits come with a Pressure Regulator (like the one shown on the right) for this exact purpose.
  • All of our engineered Compressed Air Product Kits include a Filter Separator, like this one, for point-of-use removal of solid debris & moisture.

    Air Quality: Dirty air isn’t good for anything.  It’ll clog (and eventually foul) the inner workings of pneumatic valves, motors, and cylinders.  It’s particularly detrimental to the operation of engineered compressed air products…it can obstruct the flow of Air Knives & Air Nozzles, hamper the cooling capacity of Vortex Tubes & Spot Cooling Products, and limit the vacuum (& vacuum flow) capacity of Vacuum Generators, Line Vacs, and Air Amplifiers.

Everyone here at EXAIR Corporation wants you to get the most out of your compressed air use.  If you’d like to find out more, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
Visit us on the Web
Follow me on Twitter
Like us on Facebook

 

Compressed Air Use in the Food and Beverage Industry

On our Website we have a comprehensive database of applications we have worked on with our products. These are pretty easy to find, Johns Blog will walk you through the process on how to access these applications.  While John covered Compressed Air Use in the Construction Industry, I will be covering Compressed Air Use in Food and Beverage Industry.

Appdata2
Application Database

EXAIR products are very commonly used in the food and beverage industry, from blowing water off cans before labeling, to conveying food products to hoppers for processing.  See three examples from our application data base;

foodbev1
Super Air Knife in meat processing
foodbev2
EXAIR Line Vac used in almond packaging process
foodbev3
Super Air Knife clean excess flour off belt

Use our Application Assistance Worksheet to submit information about your application. When you submit this information, we will respond with our recommendation for the EXAIR product best suited for the application. Please complete the Application Assistance Worksheet and click submit or print the completed .pdf file and fax it to us at (513) 671-3363. For immediate help, call our Application Engineering Department at 1 800 903-9247.

Jordan Shouse
Application Engineer
Send me an email
Find us on the Web 
Like us on Facebook
Twitter: @EXAIR_JS