Author: John Ball

Dynamic Viscosity and Kinematic Viscosity

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Dynamic viscosity is the frictional force between the liquid layers.  It is measured with a viscometer that uses mechanical rotational resistance to discs that are placed in the fluid.  They have the units of Centipoise (cP) or Pascal-second (Pa-s).  Kinematic Viscosity removes the density to see how the behavior of the fluid flows.  This type of viscosity is measured with funnels or tubes to see how long gravity will pull the fluid through under its own weight.  The units for this type of viscosity are Centistokes (cSt) or M2/sec. Both types of viscosities are easily changed with temperature.  To convert the kinematic viscosity to dynamic viscosity, you only need to divide the dynamic viscosity by the fluid’s density in grams per cubic centimeter (g/cm³), reference Equation 1.  Because the density changes with temperature, the conversion is fluid specific.  Why do I bring this up?  If you are looking to transfer different fluids, EXAIR has a solution for you.    

Equation 1:

Kinematic Viscosity = Dynamic Viscosity / density

Not all liquid vacuums are the same.  Have you seen motor burnout, loud noises, single directional flow, and potential electrical hazards?  EXAIR manufactures a pneumatic venturi pump to remove all those issues, the High Lift Reversible Drum Vac System.  It does not have any moving parts to wear; a two-way action to fill or expel liquid from standard drums; and is quiet.  They only use compressed air to generate a powerful vacuum to lift liquid into a drum; and with a simple twist of the knob, it will push the liquid out.  And by using compressed air, no electricity is required, making it safe to use.  They work great for fluid transfers or liquid spills, and the High Lift Reversible Drum Vac can fill a 55-gallon (208L) drum in 85 seconds from 15 feet of lift.  And with the powerful vacuum pressure, it can move thick liquid with viscosity up to 1400 Cp through 20 feet (6m) of hose.  How can this product be useful for you?  If you work with liquids in a cistern, underground tanks, higher viscous fluids, or pits, EXAIR has a product for you; the High Lift Reversible Drum Vac System.  They are reliable and simple to use, and that is why it was awarded the 2015 Product of the Year by Plant Engineering.  In this blog, I will go over the specifications and packages that EXAIR offers.

The High Lift Reversible Drum Vac pump has stainless steel construction for corrosion resistance.  It comes with a built-in safety relief valve to avoid over pressurizing and an internal float to stop any over-filling of the drum.  The air consumption is only 43 SCFM (1,218 SLPM) at 80 PSIG (5.5 Bar), and it has a quiet noise level of only 83 dBA.  Systems are available in 30-, 55- and 110-gallon capacities (114L, 208L, and 418L respectively) in different packages.

The standard package will include the two-way pump assembly, shutoff valve, 20′ (6m) vacuum hose, a 90° quick release elbow, a standpipe, and an aluminum chip wand.  The standpipe is cut to length for the properly sized drum (the drum is not included in this option).  The standpipe extends inside the drum to remove as much liquid as possible when emptying. 

The Deluxe package will include all the items shown above in the Standard package and adds a drum dolly, ABS spill recovery kit, (2) extension wands, crevice tool, skimmer tool and a magnetic toolholder.

The Premium package will include all the items in the Standard package and adds the drum with lock ring and lid, drum dolly, ABS spill recovery kit, (2) different lengths, aluminum crevice tools, skimmer tool, a magnetic toolholder and a 20′ (6m) compressed air hose.

With the relationship between dynamic and kinematic viscosities, you can determine the best EXAIR Industrial Housekeeping Product to transfer or discard.  If you have any questions about the High Lift Reversible Drum Vac System, you can contact an Application Engineer at EXAIR.  We will be happy to help you.

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

Freon-based Air Conditioning Units or Cabinet Coolers for Electrical Panels

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Whatever you do, DON’T do THIS to your panel.

These hot summer months can bring some elevated temperatures within electric control panels.  With freon-based coolers, higher ambient conditions make them less efficient; and opening the electrical panel to have a fan blow inside creates a dangerous electrical hazard.  For every 10oC rise above the operational temperature, the life of an electrical component is cut in half.  To reduce loss in productivity and premature equipment failures, it is important to keep your electrical mechanisms cool.  The EXAIR Cabinet Coolers are designed to do just that.

From right to left: Small NEMA 12, Large NEMA 12, Large NEMA 4X

We receive many questions when it comes to panel cooling as the Vortex technology is relatively new in this area.  The main question is the comparison between the Cabinet Cooler System and the Freon-based A/C panel units.  In short, the Cabinet Coolers have no moving parts to wear, do not use Freon, and require no maintenance.  But they do require clean compressed air to operate.  The Freon-based A/C units do not use compressed air, and only need electricity to operate.  In this blog, I will cover a term to consider: Total Cost of Ownership.

What do I mean by Total Cost of Ownership?  I mean that you not only take into account energy use, but also other, very real issues of owning the system.  There are some significant financial impacts on the bottom line when one considers the need for using electrical Freon panel coolers.

Initial Unit Cost – The initial cost to acquire a vortex-style Cabinet Cooler is between 1/3 and ¼ the cost to acquire a Freon-based air conditioner system. And if we consider that a typical life span for a Freon-based cooling solution is 5 years, then the yearly cost is $500.00/year.  An EXAIR Cabinet Cooler system, by comparison, will have a 20-year life span as there are no moving parts to wear out. That makes for a yearly cost of $36.45 / year. Quite a large difference between the two. Also note that over the 20-year life of an EXAIR Cabinet Cooler, the Freon unit will have to be replaced four times. We’re not taking that into account for our calculations, but assuming the cost remains the same over that time.

Installation – Because it is so easy to install an EXAIR Cabinet Cooler system, the estimated time to install is only 1 hour. One small hole to mount the unit on the top of the panel and another hole to route the thermostat to the solenoid.  With some small amount of plumbing for the compressed air and cold air distribution kit, the extent of the installation is complete. Compare that to the estimated 3-hour minimum time in order to install a Freon-based solution. With this unit, it will come with very large cut-outs on the panel to allow for the airflow to process through.

Maintenance – In this comparison, we are stating that there are no maintenance or downtime requirements for EXAIR Cabinet Cooler systems. This is another area where the EXAIR Cabinet Coolers really pull ahead of the Freon-based solutions. Yes, there is some small amount of annual filter maintenance for the compressed air supply, but a quick washing and re-installation of the sintered bronze element, and you are back in business in a very short time.  The Freon-based solution, by comparison, will require a minimum of 4 hours per year (one time per quarter) for charging Freon (due to any leaks), cleaning and replacing filters, washing the condenser, and performing compressor checks. At an estimated $80.00/hour, that is $320.00 per year for labor plus any parts. 

Operations – Here we can compare the energy use.  If we use a simple estimate for the cost of compressed air at $0.25/1000 Standard Cubic Feet, then over the course of a year of operation, a vortex-style cooling solution will run about $338.00 / year to operate. For a comparable Freon-based cooling system, it will be about $56.38 / year to operate.  But with a Freon-based system, it will need to be oversized for ambient conditions over 95oF (35oC), which will make this more comparable. 

Electrical shutdowns are expensive and annoying, and if you do not maintain the Freon-based systems regularly, the shutdowns can occur often.  In showing the Total Cost of Ownership, it shows that the EXAIR Cabinet Coolers are a great purchase.  With no moving parts, Freon, or costly preventative maintenance required, they can operate for decades by keeping your electronics cool.  For our U.S. customers, we are offering a promotion.  You will receive a1104SS Super Air Nozzle, a $197.00 value, for free as a promotional item from now until the end of August 2026 with a qualified purchase.  How can you not give them a try?  If you have any questions about Cabinet Coolers or the Sizing Guide, you can contact an Application Engineer at EXAIR.  We will be happy to help you.  Remember whenever you make a purchase, you should always look at the Total Cost of Ownership to get the entire story. 

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

Wet Receiver Tanks: Why Use Them, and How to Size Them

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9500-60 Receiver Tank

Compressed air is used to operate pneumatic systems within a facility, and it can be separated into three categories; the supply side, the demand side, and the distribution system.  The supply side will include the air compressor, after-cooler, dryer, and receiver tank.  It produces and treats the compressed air before it travels into the distribution system.  They are generally located in a compressor room somewhere in the corner of the plant.  In this blog, I would like to cover the wet receiver tank that is used as part of the supply side.

What is a receiver tank?  I like to compare pneumatic systems to electrical systems.  The receiver tanks store the pneumatic energy produced by an air compressor like a capacitor stores electrical energy.  The reason for this is to have a ready source of energy to increase efficiency and speed through the ebbs and flows of demand. 

A wet receiver, like the name imparts, is positioned downstream of the air compressor but before the air dryer.  A dry receiver would be located after the air dryer.  Some systems will utilize both types.  With the wet receiver, you remove some of the load of water that reaches the air dryer, which helps to make the air dryers more efficient and extends the life cycle.  When ambient air is compressed, the humidity will condense, making water.  Also, as air cools in the wet receiver, water vapor turns into liquid condensate—often mixed with traces of oil and dirt from the air compressor. To get rid of the contaminants, a condensate drain will be required to get rid of this unwanted liquid.

For sizing the wet receiver, it is roughly 1 to 3 gallons per cfm for a compressor.  So, for a 100 SCFM air compressor, you should have a tank that is roughly 100 to 300 gallons.  If you have large fluctuations on the demand side, you can also use Equation 1 below to calculate the minimum tank volume.  If you are using wet and dry receiver tanks in your system, you can divide the total volume.  The wet receiver tank should be one-third of the volume, and the dry receiver tank should be two-thirds of the volume. 

Equation 1:

V = T * C * (Pa) / (P1-P2)

Where:

V – Volume of receiver tank (cubic feet)

T – Time interval between pressure limits (minutes)

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

Pa – Absolute atmospheric pressure (PSIA)

P1 – Upper Pressure limit (PSIG)

P2 – Lower Pressure limit (PSIG)

Compressed air systems are the backbone of countless industries and operations.  But behind the scenes, components like the wet receiver and condensate drain play pivotal roles in ensuring these systems deliver clean, reliable air.  If you wish to discuss more ways to optimize your compressed air system, EXAIR has Application Engineers that would like to help you. 

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

Laminate Flooring – Step Up to Protect the Surface

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A manufacturer of laminated floor planks was having issues with defects prior to packaging.  The planks were made from a high-density fiberboard as the core with a top layer of a picturesque image, then sealed together.  They were getting fine material that was stuck on the surface, making them defective.  The issue was caused after the cutting process.  The fine debris remained on the surface and when the image or the sealing material was applied, it could be seen.  They tried wiping, but the solution caused scratches.  They tried blowing the surface to clear the debris, but due to the static, it would not fall off easily.  They required a good solution to improve the cleaning without slowing the process.  EXAIR’s Static Eliminators are a great product for industrial processes like this. 

In looking at the process, I recommended two pieces of a model 112242 42” Gen4 Super Ion Air Knife Kit.  The planks could come out in two spots or four spots.  (Reference photo above) To reduce compressed air usage, they could turn on or off which side is needed.  The customer asked about the mounting and compressed air attachments.  I mentioned the proper setup for the most effective blowing.  As a benefit, I offered a plumbing kit to help with the compressed air connection.  The PKI option, or Plumbing Kit Installed, has the proper amount of connection to the Super Ion Air Knife to allow for an even force across the entire knife.  I upgraded the model number with the PKI option to a model 112242PKI. 

Gen4 Super Ion Air Knife Kit

This kit will include the Gen4 Super Ion Air Knife with a PKI, a power supply, a filter, a regulator and a shim set.  The Gen4 Power Supply creates both positive and negative ions to remove any type of static.  The filter will remove bulk liquids and debris from the compressed air to keep the product clean and to optimize performance.  The Regulator is used to control the force.  This helps to not overuse the amount of compressed air required for the job.  With a regulator, you can make fine adjustments to get the proper amount of air.  For coarse adjustments, you can change shims to increase or decrease the force.  The customer was happy with the properly sized components to operate a non-contact wiping with the Gen4 Super Ion Air Knives. 

Once installed, their defect rate almost dropped to zero.  They were very happy with the cleanliness of the planks; they decided to purchase six more units.  They could place them in different areas of the lamination line to ensure a clean surface.  EXAIR manufactures a variety of Static Eliminator products.  If you feel that static is an issue in your process, you can always contact an Application Engineer to help you.  For the company above, they were “stepping” high.   

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