Video Blog: Connecting a Cabinet Cooler Thermostat and Solenoid to Power

With a Thermostat-Controlled Cabinet Cooler System, EXAIR uses a thermostat and solenoid valve to control the temperature inside an electrical panel.  They help to reduce the compressed air usage during cooler temperatures or off-peak hours.  Here is a video to demonstrate how to wire the thermostat and solenoid valve to a power source.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

 

EXAIR Threaded Heavy Duty Line Vacs™: Overview

Threaded Heavy Duty Family

Do you have operators climbing steps to dump bags of material in hoppers?  Or do you need a faster way to remove scrap from your process?  Or do you have budgetary constraints in trying to move material from pont A to point B?  If you answered yes to any of these, EXAIR can help you.  We manufacture an air operated conveyor that does not have any moving parts, very compact in design, and has a high throughput capacity.  They can attach easily to standard hoses, pipes, or sanitary flanges.   These inexpensive conveyors are designed to make conveyance safer and ergonomically better for your operators.  EXAIR calls this product line, Line Vacs™.

The Line Vacs use a small amount of compressed air to generate a vacuum by a Venturi effect.  The unique design of the generators creates a high velocity to create a powerful vacuum on one side.  Once the product reaches the throat area of the Line Vac, the compressed air will carry the product the rest of the way.  We can reach horizontal distances up to 100 feet (30 meters) away and vertical heights up to 20 feet (6 meters).  EXAIR manufactures a variety of Line Vacs in different sizes, styles, and materials.  In this blog, I will cover the Threaded Heavy Duty Line Vacs.

Threaded Heavy Duty Line Vac

The Threaded Heavy Duty Line Vacs are designed to convert regular piping into a powerful conveying system.  They range from ¾” NPT to 3” NPT and can connect easily to PVC and pipe fittings.  The construction is made from a hardened alloy steel to resist abrasion which can occur prematurely with aluminum or stainless steel.  The Threaded Heavy Duty Line Vac can create a higher vacuum level to pick up heavier objects as well as conveying larger volume of material.  As a kit, the Line Vac will come with a filter, regulator, and a mounting bracket.  This adds overall value in mounting, controlling, and protecting the Line Vac for years to come.  This simple device is a great product to use in rugged industrial applications.

If you need to convey heavy materials like steel shot or abrasive products like ceramic or shot-blasting media, the Heavy Duty Line Vac could be a blessing for you.  Not only can they transfer material safely and quickly, but they also will help in saving the backs and knees of your operators.  If you would like to discuss your application further, please contact an Application Engineer at EXAIR.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

Return on Investment: A Calculation to Support Using EXAIR Products

EXAIR Products

Return on Investment, or ROI, is the ratio of profit over total investment.  Many people use it to evaluate stocks, financial markets, capital equipment, etc.  It is a quantitative way in determining the validity of an investment or project.   Recently, there has been a big push by power companies for energy efficiency within the manufacturing sectors.  EXAIR, in partnership with Energy Star, has been manufacturing safe and efficient products since 1983.  An ROI will give a measurable value to communicate more thoroughly with your financial decision-makers.

Equation 1:  ROI = (Total annual savings – Total Project Cost) / Project Cost * 100

In an earlier blog, I wrote about a project with a company in calculating compressed air savings; “EXAIR Super Air Nozzles: 38 Day ROI Saves Money”.  In this blog, I determined the total compressed air savings and the payback period by switching to EXAIR Super Air Nozzles.  The payback period is the amount of time it will take for the project to pay for itself; and for the above manufacturer, it was calculated at 38 days.  To associate this to a Return on Investment, I will use that information from the blog to calculate the ROI.  Equation 1 shows that for any positive ROI value means that the payback period is less than one year.  The larger the ROI value, the quicker the investment that you made will start earning money for your company.

The first part of the equation, Total Annual Savings, is calculated by amount of compressed air savings when using EXAIR Super Air Nozzles in a blow-off application.  When this customer switched from copper tubes, which uses an excessive amount of compressed air, to the model 1110SS Super Air Nozzles, the compressed air consumption dropped by 80%.  Compressed air is considered a fourth utility in manufacturing plants because the amount of electricity to make compressed air is very large.  At a rate of $0.08/KWh, each Super Air Nozzle saved this company $306.00 per year.  As described in the blog, the facility used four nozzles per machine, and they had 25 machines in their facility.  The total annual savings is calculated as follows:

Equation 2: Total Annual Savings = $306 * 4 * 25 = $30,600 per year.

The second part of the equation, Total Project Cost, is the cost of the nozzles plus the labor to install them onto the machines.  The model 1110SS Super Air Nozzle has a price of $46.00 each.  These engineered nozzles are designed to use less compressed air by entraining the “free” ambient air, making them very efficient for blow-off applications.  The amount of time required to install four nozzles to each machine was 1 hour.  This time included tapping, fixturing, and testing each setup.  The labor rate that I will use in this example is $75.00 per hour (you can modify this to your current labor rate).  The labor cost to install four nozzles is $75.00 per machine.   The Total Project Cost can be calculated as follows:

Equation 3: Total Project Cost = ($46 * 100 nozzles) + ($75 * 25 machines) = $6,475

With the Total Annual Cost and the Project Cost known, we can insert these values into Equation 1 to calculate the ROI:

ROI = (Total annual savings – Total Project Cost) / Project Cost * 100

ROI = ($30,600 – $6,475)/$6,475 * 100

ROI = 373%

When a decision maker sees this large of a value for a Return on Investment, it makes it very easy to proceed with an energy-saving project to install EXAIR Super Air Nozzles on their machines.

Besides cost savings, there are some additional things that EXAIR products can provide.  It may be difficult to put a value on the savings, but these products can improve your process and save your company money.  First, they can reduce repair or replacement costs on maintenance items for the air compressors.  If you use less compressed air, then the running hours of the compressor is reduced.  Second, some things that can be easily overlooked is safety.  The Intelligent Compressed Air® products have a much lower sound level where expensive PPEs may not be required.  Another safety feature is dead-end pressure in which the operator could risk health in using open pipe or substandard nozzles.  Some other enhancements in using EXAIR products are improved system reliability, increased productivity, and reduced unscheduled downtimes (typically seen with broken plastic nozzles).  These added benefits plus the short ROI can validate a energy-savings project in your facility.

Power companies see the great value in using efficient engineered products in compressed air systems as they currently offer rebates.  If you need help to see if your local power company does offer rebates, EXAIR can research the programs for you.  The rebates will reduce the cost of each nozzle as well as cut the overall project cost.  EXAIR also offers an Efficiency Lab.  We will compare your current blowing device with an EXAIR product to find any compressed air savings.  It is simple to do.  Just fill out the form, Efficiency Lab, and ship your product to us.  We will test each product with calibrated equipment and report the results.  The comprehensive report will include compressed air savings which can be used for the ROI calculations above.  For the company above, they were able to save $30,600 a year with a ROI at 373%.  If you would like to team up with EXAIR to establish annual savings, project improvements, and rebates, you can contact an Application Engineer to get started.  We will be happy to work with you.

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

EXAIR External Mix Atomizing Nozzles: Overview

No Drip Atomizing Family

In today’s market, the cost of consumable products are on the rise; especially with paints, oils, and yes, even the cost of water.  You can help alleviate some of that cost by being more effective in spraying with less liquid.  The EXAIR Atomizing Nozzles can accomplish both of these objectives.  By using compressed air, the liquid can be sheared into smaller micron-sized droplets.  As a reference, if the diameter of a particle is reduced by one-half, this will multiply the number of droplets by eight.  With a smaller diameter, it will increase the surface area and coverage of the droplets; thus, requiring less liquid in your application.  In combination with a variety of spray patterns, you can accurately target the liquid onto the product instead of around the product.  EXAIR manufactures three families of Atomizing Nozzles; Internal Mix, External Mix, and the Siphon Fed.  In this blog, I will be focusing on the External Mix Atomizing Nozzles.

The External Mix Atomizing Nozzles are designed, like the name suggests, to atomize the liquid outside the nozzle.  This means that the liquid and air streams will not come into contact until it reaches the outward atomizing area (reference photo above).  Both the air and liquid supply will have to be pressurized, and they can be controlled independently.  This type of Atomizing Nozzle will allow for higher viscous fluids, above 300 CPS, to be used in spraying applications.  With the external mixing, it will help to reduce the drying effect of the solution and interrupting the system.  EXAIR manufactures these nozzles with stainless-steel construction making them compatible with many different kinds of liquids and can be used in many applications like washing, coating, cooling, quenching, and dust control.

EB1040SS washing wine bottles.

EXAIR carries three different body sizes in 1/8” NPT, ¼” NPT, and ½” NPT ports; so, you can create a light mist or a monsoon.  The maximum liquid flow rates through each body size is controlled by the air caps and liquid caps.  These caps are easily interchangeable for each body size to modify the spray patterns, control the amount of fluid, and reduce any downtime if cleaning is required.  The amount of liquid to be applied is easily adjusted by the inlet air pressure, liquid pressure, and the liquid adjusting stem.  So, you can dial in the exact amount of fluid required for your process to eliminate any waste or excess. They have a compact design to mount inside tight areas, and we also carry mounting brackets for easy attachment and positioning.   Versatility is very important in saving, applying, and spraying costly fluids, and the External Mix Atomizing Nozzles have it.

To help reduce excess fluid even more, EXAIR has a No Drip option.  This patented design is used to keep the expensive liquid from dripping out of the Atomizing Nozzles during off cycles.  When the compressed air is turned off, a valve inside the body will create a seal on the liquid side.  For delicate applications, the unwanted drips will not occur with the No Drip option to ruin the finish of your product.  This option also enhances the function of the External Mix Atomizing Nozzle for intermittent processes.  It will keep the liquid inside the body of the nozzle; so, when air pressure is applied, the Atomizing Nozzle will give an instant spray.  The minimum air pressure required to open the No Drip valve is 30 PSIG (2.1 bar) for the ¼” NPT and the ½” NPT port sizes, and 20 PSIG (1.4 bar) for the 1/8” port size; still allowing for flexibility in compressed air adjustments.  Unlike some manufacturers, there is no need to run a separate compressed air line to operate the no drip function.  The External Mix Atomizing Nozzles with the No Drip options can give you the best performance in efficiency, effectiveness, and flexibility without any drips.

If you need to maximize the liquid dispersion and minimize liquid consumption, the EXAIR Atomizing Nozzles are the products to use.  Even if you have a viscous fluid, the External Mix Atomizing Nozzles can still shear the drops into a fine mist, saving the amount of expensive consumable oils and liquids.  If you have an application involving liquid spraying, an Application Engineer at EXAIR can help determine the correct model for you.

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

More Force is not Always Better for Cleaning Glass

Glass Annealing Machine with model 110230

A float glass company purchased an EXAIR model 110230 Super Air Knife kit to clean the surface of glass sheets.  The production manager watched the video of the performance of the Super Air Knife, and he was amazed at the efficiency, effectiveness, and safety that they could provide.  (We have many EXAIR Product videos here).  After they received the Super Air Knife, they mounted it after the annealing process to remove any specks of dirt and debris prior to the final visual inspection.  They were getting some false rejections from contamination that remained on the sheets, and they believed that they needed more force to better clean the surface of the glass.

The blowing system was operating at 73 PSIG (5 bar) air pressure, the maximum amount that could be supplied at the machine.  With the dynamics of the Super Air Knife, the blowing force could be increased by changing the shim thickness.  The plant manager contacted me about the characteristics in force and flow by changing from the standard 0.002” (0.05mm) thick shim to the 0.003” (0.08mm) or 0.004” (0.1mm) thick shim.  (These shims are Included in the shim set for aluminum Super Air Knife kits along with a 0.001” (0.025mm) thick shim).  As an Application Engineer at EXAIR, I was inquisitive about the application and wanted to do a “forensic” analysis of the system to generate the best suggestion.  So, I had him send me pictures of their setup.

With non-conductive materials like glass and plastic, static can be a huge issue.  Static forces can easily be generated and will cause dirt and debris to “stick” to a surface.  This attraction is very strong and will make it very difficult to remove.  If the static force can be neutralized, then the contamination can easily be removed from a non-conductive surface.

With this understanding, my initial suggestion for the company above was to remove the static charges from the surface of the glass with an EXAIR Static Eliminator.  With the complimentary design of the Super Air Knife, it is simple to mount an Ionizing Bar directly to the Super Air Knife that they currently installed.  I recommended a model 8030, 30” (762mm) long Gen4 Ionizing Bar, and a model 7960 Power Supply to transform the Super Air Knife into a Gen4 Super Ion Air Knife.  The positive and negative ions that are generated by the Gen4 Ionizing Bar can be carried by the laminar air flow of the Super Air Knife to treat the surface.  This combination can work well to remove static charges up to 20 feet (6m) away.  Once the static is removed, the force of the air stream would easily remove any dust or debris from the glass surface.

Gen4 Super Ion Air Knife

As an added note from the picture above, I recommended a different position for the Super Air Knife, or soon to be Gen4 Super Ion Air Knife to optimize the blowing area.  The glass company had the air knife positioned to blow straight across the surface of the glass.  For proper cleaning and better contact time, I suggested to mount the Super Air Knife with the Ionizing Bar about 6” (152mm) above the surface of the glass and angle it to about 45 degrees.  This would increase the contact angle and allow for a better blowing force to remove all the debris.  By adding the Gen4 Ionizing Bar and adjusting the blowing angle, they were able to reduce the air pressure from 73 PISG (5 bar) to 30 PSIG (2 bar); saving compressed air and reducing false rejections.

Pictures are always helpful in analyzing an application.  With the company above, we were able to optimize their cleaning process and reduce the total amount of compressed air required.  If you find that you need more force to clean a non-conductive surface, EXAIR Static Eliminators will resolve these static problems.  If you would like to discuss your application with an Application Engineer at EXAIR, we can go through the “forensics” analysis for optimization.

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

EXAIR Air Jets: Overview

Air Jet Family

EXAIR manufactures a variety of Air Nozzles and Jets to safely, efficiently and effectively blow compressed air. There are many different styles that can best fit specific applications. In this blog, I am going to discuss the EXAIR Air Jets. They are designed to entrain a high volume of ambient air to give a moderate blowing force. Similar to the Air Amplifiers, these miniature devices use very little compressed air to achieve an effective blowing for removing debris, drying parts, or cooling hot products. EXAIR manufactures two different styles, the High Velocity Air Jet and the Adjustable Air Jet.

The Air Jets use a Coanda profile for blowing. The Coanda effect was named after a Romanian aerodynamic pioneer, Henri Coanda who discovered a fluid flow phenomenon. He stated that “a jet of fluid emerging from an orifice to follow an adjacent flat or curved surface and to entrain fluid from the surroundings so that a region of lower pressure develops” (1). Since air is a fluid, it will react in the same manner. The EXAIR Air Jets create a high velocity air stream along an engineered profile. So, as the air “hugs” the profile, a low pressure is created which will draw in ambient air. The unique design of the Air Jet utilizes a ring jet of compressed air to produce that low pressure at the entrance, entraining the surrounding ambient air. This makes the Air Jet very efficient as it utilizes more ambient air than compressed air.

Depending on the environment or application, the Air Jets come in two types of material; brass and stainless steel. The High Velocity Air Jets use a shim to set a gap. The gap can be changed by installing a different thickness of shim to increase or decrease the blowing intensity. These shims in conjunction with a regulator gives versatility for a wide range of applications. If the desired blowing force needs to be changed for different types of products or flexibility is required “on the fly”, the Adjustable Air Jet would be recommended. It has a micrometer gap indicator to set the desired result. By twisting the plug of the Adjustable Air Jet, you can get output flows from a gentle breeze to a blast. What makes both Air Jets unique is the design. They meet the OSHA standard for noise level and dead-end pressure. If you block the output of the Air Jets, the pressure will not exceed the OSHA safety requirement for dead-end pressure. Also, the inlet and/or outlet can both be ducted for remote positioning.

Model 6013 High Velocity Air Jets help dry an engine casting

Our accessories can make the Air Jets easier to use.   We have Stay Set Hoses for easy connections and maneuverability. The Stay Set Hoses come in a variety of lengths from 6” (152mm) to 36” (915mm) and once you set the position, the Stay Set Hose will keep the Air Jet stationary even during blowing. You can add a Magnetic Base with the Stay Set Hose and Air Jet to mount the blowing unit right to a metal fixture. It has a 100 lb. (45.5Kg) pulling force to keep the Air Jet from moving until you need to move it. The bases come with a ¼ turn shut-off valve and in a single or dual output configuration. In addition to the above accessories, we also offer a model 9040 Foot Pedal valve for operator control of the duration of blowing with their foot, allowing the use both of their hands.

With the cost to make the compressed air utility being so high, it is important to use it as efficiently as possible. The High Velocity Air Jet and Adjustable Air Jet have the ability to give you effective blowing for removing debris, drying parts, or cooling objects without using a large amount of compressed air. With the accessory items included, you can set up an improved blowing station that will be effective, quiet, and efficient for your operators. The Air Jets are flexible and adaptable to be used in numerous types of blowing applications. If you have any questions about the Air Jets or if you would like to discuss any applications, you can contact an Application Engineer at EXAIR.

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

 

(1) Note: Coanda effect by Wikipedia.org

Laminar Flow vs. Turbulent Flow – Calculations and Examples

Super Air Knife

What is laminar flow and turbulent flow?  Osborne Reynolds popularized this phenomenon with a dimensionless number, Re. This number is the ratio of the inertial forces to the viscous forces.  If the inertial forces are dominant over the viscous forces, the fluid will act in a violent and chaotic manner.  The formula to determine the Reynolds number is as follows:

Equation 1:  Re = V * Dh/u

Re – Reynolds Number (no dimensions)

V – Velocity (Feet/sec or Meters/sec)

Dh – hydraulic diameter (Feet or Meters)

u – Kinematic Viscosity (Feet^2/sec or Meter^2/sec)

The value of Re will determine the state in which the fluid (liquid or gas) will move.  If the Reynolds number, Re, is below 2300, then it is considered laminar (streamline and predictable).  If Re is greater than 4000, then it is considered turbulent (chaotic and disarrayed).  The area between these two numbers is the transitional area where you start to get small eddy currents and velocities in a non-linear direction.  When it comes to effective blowing, cleaning and lower noise levels, laminar flow is optimal.

Let’s do a comparison of Reynolds numbers between the EXAIR Super Air Knife and a blower-type air knife.  Both products are designed to clean and blow off wide areas like conveyor belts.  The EXAIR Super Air Knife is powered by compressed air, and the blower-type air knife is powered by an air blower.  The main difference between the two products is the dimension of the slot opening.  The Super Air Knife has a gap opening of 0.002″ (0.05mm).  It uses the force of the compressed air to “push” it through the small opening to create a strong velocity.  A blower does not generate a high force, so the opening of the blower-type air knife has to be larger to overcome any back pressure the opening creates.  The gap opening is typically 0.5″ (13mm).  From Equation 1 above, the gap opening helps determine the hydraulic diameter, Dh.  The hydraulic diameter is an equivalent tube diameter from a non-circular flow area.  Since both the Super Air Knives and blower-type air knives have rectangular cross sections, the Dh can be calculated as follows:

Equation 2: Dh = 2 * a * b/ (a + b)

Dh – Hydraulic Diameter (feet or meter)

a – Gap Opening (feet or meter)

b – Gap Width (feet or meter)

If we compare for example a standard 12″ wide air knife, we can calculate the hydraulic diameter, Dh, by using Equation 2:

Hydraulic Diameter Calculations

 

The exit velocity of the Super Air Knives can be changed by regulating the air pressure.  The higher the air pressure, the higher the velocity.  The blower type air knives can use a blower with a variable frequency drive (VFD) to change the exit velocity .  A reasonable air pressure for the Super Air Knife is 80 PSIG, and the exit velocity is near 540 ft/sec (164 m/s).  To equate this to a blower system, the size of the blower will determine the maximum velocity.  To do this comparison, I will use the same velocity as the Super Air Knife.  With the kinematic viscosity of air, it has a value of 0.000164 ft^2/sec (0.000015 m^2/sec) at 70 deg. F (21 deg C).  Now we have all the information for the comparison, and we can now find the Reynolds number from Equation 1:

Reynolds Number Calculation

As you can see from the above calculations, the Super Air Knife has a Reynolds number, Re, below 2300.  The flow characteristic is in the region of laminar (predictable and streamline).  The blower air knife has a Reynolds number, Re, above 4000.  The flow dynamic coming out of the blower-type air knife is turbulent (chaotic and disoriented).  To better show the difference in laminar flow and turbulent flow, I have a picture below that shows both states with water as a fluid (being that air is an invisible fluid).   Here is an example of water  coming out of a drain pipe at Cave Run Lake (first picture below).  With the inertial forces much higher than the viscosity of the water, it is in a turbulent state;  loud and disorderly.  Reynolds number is greater than 4000.  The water is traveling in different directions, even upstream.  As the water flows into the mouth of the river after the channel (second picture below), the waves transform from a violent mess into a quiet, calm stream flowing in the same direction.  This is laminar flow (Re is less than 2300).

Turbulent Water from Pipe
Turbulent Water from Pipe

 

From Channel to River
From Channel to River

With the engineered design of the Super Air Knife, the thin slot helps to create that laminar flow.  All the air is moving in the same direction, working together to give a higher force to remove debris.  If you have turbulent flow like that of a blower air knife, the noise level is much higher, and the disoriented forces are less effective in blowing.  Turbulence is useful for mixing, but horrible for trying to clean or wipe a conveyor belt.  If you have any open pipes, drilled pipes or blower-type air knives in your application, you should try an EXAIR product to see the difference.  An Application Engineers can help you take advantage of laminar airflow.

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