EXAIR Line Vacs™: We can do specials…

Here is a question; what is an eductor?    Eductors are also called ejectors, Venturi jets, aspirators, jet mixers, or jet pumps.  Eductors use either compressed gas or liquid to generate a vacuum by a Venturi effect which is based on Bernoulli’s equation.  (You can read more about the person here, “People of Interest: Giovanni Battista Venturi March 15, 1746 – April 24, 1822 By Tyler Daniel”.)  They can be used for vessel evacuation, gas sampling, pump priming, venting, and blending.  EXAIR Line Vacs work on this same principle in creating a Venturi vacuum by using compressed gas.  In this blog, I will cover the design, verification, and testing that EXAIR provided for a customer’s special.    

For this customer, the design was based around our 2” and 1” 316SS Line Vacs.  They required ISO flanges on the vacuum and exhaust sides to match their piping connections for gas sampling.  They would supply nitrogen to the inlet port as a carrier gas to generate the venturi and to mix with the sample gas.  Since the accuracy of the test is dependent on the amount of each gas, we had to test the operations of the Line Vacs at different conditions. 

First, EXAIR designed these special Line Vacs to get approval.  Once the customer approved, EXAIR had to make a strong effort to meet the other criteria that was requested.  Generally, with our standard Line Vacs, we use our test data with estimated conveyance rates, inlet flow rates, and vacuum pressures measured at 80 PSIG (5.5 bar).  For these special Line Vacs, we had to do a bit more work because it was for gas sampling.  This was not a problem for us.  EXAIR has many calibrated instruments to accurately measure different conditions.  For this customer, we had to measure the inlet flow, suction pressure, velocity, and maximum back pressure at different inlet pressures.  We also had to create another chart showing the exhaust velocities with a back pressure present. 

From these details, the customer could calculate the amount of nitrogen that would be introduced to the gas sample at different pressures and backpressures.  And, as an added preference, they requested us to do a leak check after assembly.  We were willing to buy the flange blanks and add this test procedure to the router.  We looked for leaks between the cap and body of the special Line Vac, as well as the flanges to verify that gas was not escaping.  EXAIR tries to support our customers to the best of our abilities.  For this customer, we worked together to provide the needed information for their setup.    

The reason that I wrote this blog was to show that EXAIR has the capabilities to make special items for specific applications.  If we need to use different materials, design configurations, and even present test data, we can decide the best course of action.  With special products, they are unique to customers in fit, form and function as a solution, whether for end-users or OEMs.  For the special Line Vac above, we presented the data as related to an eductor for this customer’s decision to place the order.  If you would like to see if EXAIR can make a special product for you, please do not hesitate in contacting an Application Engineer at EXAIR.  We will be happy to work with you. 

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

EXAIR Internationally

I would like to share a conversation with a company that I visited in Singapore.  They manufactured natural rubber material, and they were having issues with material sticking inside the oven.  In our conversation, they would have to stop the process in order to clean the area near the chopping blades where the rubber material would collect.  The system would have to be shut down for the entire day to clean the oven which lost profits and production yields.  I was familiar with this company, as they were global. 

I remembered that I helped their American counterpart with the exact same application.  I was able to make a quick recommendation for the same product; two model 110260SSPKI 60” (1,524mm) wide Stainless Steel Super Air Knives with Plumbing Kits.  They purchased and installed the Super Air Knives to generate an air curtain to keep the rubber material from sticking to the wall and forcing it into the grinder below.  This helped them to save a lot of money for unscheduled shutdowns.  If the U.S.A. company was able to share this information with their foreign counterpart, it would have been a great cost savings for the corporation as a whole. 

Since the establishment of EXAIR in 1983, customer satisfaction, quality, and quick turnaround have always been the cornerstone of our business model.   And with this type of business model, our company continues to grow each year.  Now EXAIR is recognized as a brand of excellence worldwide.  With thousands of products in stock, we are able to ship with over a 99.9% on-time delivery.  EXAIR offers free expert technical advice and share solutions to pneumatic issues through EXAIR Blogs, application library, and social media. 

In today’s market, many companies are global and have plants and facilities throughout the world.  If details like cost savings, safety, increased productivity, problem solving, and energy efficiency would be shared; it would be very beneficial for everyone.  It can help to grow profits, protect employees, improve throughput, and save energy which will help to protect the environment.  Since EXAIR is a leader in these areas with compressed air products, we can help you and your affiliates with pneumatic solutions. 

EXAIR sells direct in the U.S.A and Canada, and we have over 50 distributors located throughout the rest of the world.  EXAIR has structured our world-wide presence by country in our International Map located on our website.  It is simple to use.  To find a distributor, click on this link, International.  Fill in your Name, Email, and Country you wish to find.  We also ask if you would like to receive news about EXAIR products in the future.  You can select “Yes” or “No”.  If you would like to obtain information monthly from EXAIR about new products, special notices, or featured products, then click “Yes”.  And, if we do not have a distributor in your area, EXAIR has an International Department that can assist you directly. 

There are many ways to save money within your industry.  And one way is to use your compressed air efficiently.  If you or your affiliates use compressed air to cool, dry, clean, convey, vacuum, or remove static electricity, EXAIR can improve your process.  And if you have locations outside of U.S. and Canada, we can still help you.  You can contact us directly or visit our International Map.  You may find someone near you that can speak your language and discuss the values that EXAIR can provide.  You will be glad that you did.  And if we do not have anyone in the country and you wish to speak to us about becoming a Distributor, you can contact us through our form here: International Distribution.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

Photo: International Flags by GDJPixabay license.

High-Power Stainless Steel Line Vacs for Dental Work

A manufacturing plant had machines that would process ceramic 6mm beads into blanks for machining small components in the dental industry.  Ceramic can be used in items like braces, crowns, root implants, and bridges.  From the blanks above, they milled crowns and bridges in specific designs to fit in the patient’s mouth.  In their current process, they used a belt conveyor that would move the ceramic beads into a hopper above the sintering machines.  They had a failure with their conveyor, and they had to shut down the machines. 

They contacted the conveyor manufacturer for assistance.  Because of the complexity of conveying systems, as compared to EXAIR Line Vacs, they needed time to evaluate.  They had to determine if it was the motor, the belt, the gear box, pulley bearings, or electrical system.  Depending on which item that failed, there was a possibility that it would not be in stock or would have to be sent off-site for repair.  With this amount of downtime, it would cost the company money and delays in shipments.  Being that they were under pressure to meet deadlines, they contacted EXAIR to see if we could help. 

Air Operated Conveyor

In discussing their layout, the hopper was 10 feet (3 meters) away from the supply container, and the opening of the hopper was 10 feet (3 meters) above the floor.  These lengths were well within the limits of the EXAIR Line Vacs.  The bulk density was 70 lbs./ft3 (1,140 Kg/M3), and they needed 316SS since the equipment was used for medical devices.   I suggested the model 6964-316 2” 316SS Line Vac Kit.  At those distances, I mentioned that we could move roughly 10 lbs./min. (275 Kg/hr.) of ceramic beads at 80 PSIG (5.5 Bar) air pressure.  They wondered if we could get a bit more power from our Line Vacs.  This we can do!!!  EXAIR can modify our Line Vacs to fit into different applications.  We can modify the inlet and outlet connections from a smooth connect for hose to a threaded connection for pipe, or vice versa.  We can also modify the generator for our Stainless Steel Line Vacs to increase the capacity.  This would be our “HP” (for High Power) prefix.  I then recommended the model HP6964-316 High-Power 316SS Line Vac Kit.   This model has a conveyance rate near 13.3 lbs./min. (362 Kg/hr.) at 80 PSIG (5.5 bar) air pressure.  This was perfect for their operation.  With the different hopper volumes, they could adjust the inlet air pressure to increase or decrease the conveyance rates. 

The next question they asked was, how fast can we get them a special unit?   EXAIR stocks every cataloged model number for same-day shipping with orders placed before 2 p.m. EST.  For the “HP” special, we were able to ship the next day to get their operation running.  They did mention to me afterwards that they wished they knew about the EXAIR Line Vacs before they purchased the conveyor system.  Since the Line Vacs do not have any moving parts or motors to wear, they would have years of non-maintenance operations.      

If your company relies on conveying systems to move product, you may want to have an EXAIR Line Vac on-hand just in case of an emergency.  When things go wrong, you do not want to be down any longer than needed.  If you need help in sizing the correct Line Vac for your application, you can contact an Application Engineer at EXAIR.  We will be happy to help.

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

Photo: Tooth Replacement by dental-innoPixabay License

The Difference Between a Hose and a Tube and Their Effect on Pressure Drop

EXAIR has been manufacturing Intelligent Compressed Air Products since 1983. They are engineered with the highest of quality, efficiency, safety, and effectiveness in mind. Since compressed air is the source for operation, the performance limitations can be defined by its supply. With EXAIR products and pneumatic equipment, you will need a way to transfer the compressed air from the source to the point-of-use. There are three main ways; pipes, hoses and tubes. In this blog, I will compare the difference between compressed air hoses and compressed air tubes.

The basic difference between a compressed air hose and a compressed air tube is the way the diameter is defined.   A hose is measured by the inner diameter while a tube is measured by the outer diameter. As an example, a 3/8” compressed air hose has an inner diameter of 3/8”. While a 3/8” compressed air tube has an outer diameter that measures 3/8”. Thus, the inner diameter of the tube will be smaller than the hose.

Why do I bring this up? Pressure drop… Pressure Drop is a waste of energy, and it reduces the ability of your compressed air system to do work. To cut waste, we need to reduce pressure drop.  If we look at the equation for pressure drop, we can find the factors that play an important role. Equation 1 shows an equation for pressure drop.

Equation 1:

From Equation 1, differential pressure is controlled by the flow of compressed air, the length of the pipe, the diameter of the pipe, and the inlet pressure. As you can see, the pressure drop is inversely affected by the inner diameter to the fifth power. So, if the inner diameter of the pipe is twice as small, the pressure drop will increase by 25, or 32 times.

As an example, we have a 1/2″ black schedule 40 pipe which has an I.D. of 0.622″.  We use this pipe to flow 40 SCFM of compressed air at 100 PSIG through 100 feet.  What would be the pressure drop?  With Equation 1, imperial units, we get a pressure drop of 1.28 * (40 SCFM/60) ^1.85 * 100 feet / ((0.622″)^5 * 100 PSIG) = 6.5 PSID.  Thus, you started with 100 PSIG, and at the end of the pipe, you will only have (100 PSI – 6.5 PSI) = 93.5 PSIG to use.  Sizing pipe is very important when supplying compressed air to your system as pressure drop is a waste of energy.

Let’s revisit the 3/8” hose and 3/8” tube. The 3/8” hose has an inner diameter of 0.375”, and the 3/8” tube has an inner diameter of 0.25”. In keeping the same variables except for the diameter, we can make a pressure drop comparison in Equation 2.

Equation 2:

As you can see, by using a 3/8” tube in the process instead of the 3/8” hose, the pressure drop will be 7.6 times higher.  As an example, if the pressure drop through a 3/8″ hose is 1 PSID, and you decide to switch out to a 3/8″ tube.  The pressure drop will then be 7.6 PSID, and a big loss of pressure.

Diameters: 3/8″ Pipe vs. 3/8″ tube

At EXAIR, we want to make sure that our customers are able to get the most from our products. To do this, we need to properly size the compressed air lines. Within our installation sheets for our Super Air Knives, we recommend the infeed pipe sizes for each air knife at different lengths. (You will have to sign into the website to download).  We also have an excerpt about replacing schedule 40 pipe with a compressed air hose. We state; “If compressed air hose is used, always go one size larger than the recommended pipe size due to the smaller I.D. of hose”. Here is the reason. The 1/4” NPT Schedule 40 pipe has an inner diameter of 0.364” (9.2mm). Since the 3/8” compressed air hose has an inner diameter of 0.375” (9.5mm), the diameter will not create any additional pressure drop. Some industrial facilities like to use compressed air tubing instead of hoses. This is fine as long as the inner diameters match appropriately with the recommended pipe in the installation sheets. Then you can reduce waste from pressure drop and get the most from your EXAIR products.

With the diameter being such a significant role in creating pressure drop, it is very important to understand the type of connections to your pneumatic devices; i.e. hoses, pipes, or tubes. In most cases, this could be the reason for under performance of your pneumatic products, as well as wasting money within your compressed air system. If you would like to discuss further the ways to save energy and reduce pressure drops, an Application Engineer at EXAIR will be happy to help you.

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

Photo: Manometers by WebLab24_Siti_Web . Pixabay License