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

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

Heavy Duty Line Vac Solves Alumina Spillage Problem

Spilled alumina material which needs to be vacuumed and returned to the main hopper.

The image above shows spillage of small alumina particles at an aluminum manufacturing plant in South America.  This customer needed a method to vacuum the spilled material and return it to the main hopper.  The ideal solution needed to be compact, simple, and provide repeatable results.  All of these are key aspects of EXAIR Line Vacs, so we began discussing application variables to make a solution recommendation.

Whenever we consider Line Vac applications we always explore the following variables:

  •      Bulk density of the material
  •      Size of the material
  •      Conveyance height
  •      Conveyance distance
  •      Required conveyance rate
  •      Available compressed air supply

The spilled alumina in this application has a bulk density of 1.1 g/cm³ (~68.7 pounds/ft³) which needs to be conveyed to a height of 3.3m (~11ft.).  The conveyance rate is not mandated, but the alumina particles are rather small in diameter and the customer wanted to move as much material as possible in as little time as possible.  Compressed air is readily available at proper pressures and flows, so we were left to determine whether a Line Vac could be a viable solution.  Fortunately we’ve found success in transferring alumina with our Line Vacs in multiple applications before, so we were confident we could find a solution here as well.

The height of this application is 3308mm (~11ft.) – an easy conveyance height for an EXAIR Line Vac.

After exploring the specifics of this application we determined the best solution to be the 2” Heavy Duty Line Vac model 150200.  The 150200 Heavy Duty Line Vac can easily move the alumina to a height of 3.3m at an estimated conveyance rate of 11kg/minute (25 pounds/minute).  There are no moving parts to wear out, which means little to no maintenance and reliable performance each time the Line Vac is used.

Our local distributor assisted with product procurement and in-country technical support.  So even though this customer was in a different continent, we were able to quickly get them the assistance and products they needed to solve their problems.

If you have an application and would like to work with an EXAIR Application Engineer, give us a call and we’ll be happy to help.  1-800-903-9247.

EXAIR Corporation Application Engineers
Techelp@EXAIR.com

Why Is Ambient Air Entrainment Needed For Pneumatic Conveyance?

When attempting to convey material pneumatically it can sometimes not work as one may hope. This could be due to the lack of ambient air entrainment to generate the vacuum flow which lifts the material away and moves the material. The video above gives a brief example of this.

If you would like to discuss pneumatic conveying products or processes, please contact us. EXAIR’s Line Vac air operated conveyors are a great solution for manual “bucket and ladder” applications, hopper loading, scrap conveyance, media recovery and more!

Brian Farno
Application Engineer
BrianFarno@EXAIR.com
@EXAIR_BF