Person of Interest: Giovanni Battista Venturi

Published on by John BallLeave a comment

Giovanni Battista Venturi was an Italian physicist that was born in Bibbiano, Italy on March 15, 1746.  He died at the age of 76 on April 24, 1822.  During his early life, Giovanni was ordained as a priest at the age of 23; and, he became a professor of geometry and philosophy at the University of Modena at the age of 28.    He moved to Paris France where he worked with other scholars to expand his knowledge of physics and chemistry.  In 1797, he wrote a dissertation on the now famous “Venturi effect”.  However, an actual device was never created or applied until 1888 where Clemens Herschel was awarded the patent for the first Venturi tube.

Venturi Tube

The Venturi effect is a decrease in fluid pressure when fluid flows through a constricted area of a pipe.  In other words, as the diameter becomes smaller, the fluid velocity becomes faster.  This increase in velocity will create a lower pressure just past the constricted area.  when designed correctly, you can create a strong vacuum or a large negative pressure.

E-Vac design

The EXAIR E-Vac® Vacuum Generators use this phenomenon founded by Giovanni Venturi by using compressed air as the fluid.  This type of Venturi tube restricts the internal area to generate a fast velocity through the body creating a vacuum pressure for suction.  EXAIR offers three types of Venturi tubes; low vacuum, high vacuum and adjustable.  The high vacuum generators can create a vacuum level as high as 27” Hg (71 KPa).  The Adjustable E-Vacs can alter the internal air velocities by turning the body and getting different vacuum pressures.  Without any moving parts or electric motors to wear, the EXAIR E-Vacs are a simple design that is very durable, effective and long-lasting.  A great product for applications like pick and place, clamping, lifting and vacuum forming,

The Venturi effect was discovered in 1797, brought into existence in 1888, and is still used in vacuum applications to this very day.  If you have an application where a Venturi tube could help you, please contact an Application Engineer.  We will be happy to assist you.

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

 

Photo: Venturi Tube with labels by ComputerGeezer an Geof.  GNU Free Documentation License

Lower Operating Costs by Minimizing Compressed Air Leaks

Published on by exaircorpLeave a comment

Almost every industry uses compressed air in some capacity. It is often referred to as the “fourth utility” In an industrial setting, next to water, gas and electric. and in many cases, is the largest energy user in the plant. With an average cost of $ 0.25 per every 1000 Standard Cubic Feet used, compressed air can be expensive to produce so it is very important to use this utility as efficiently as possible. When evaluating the performance of a compressed air system, it’s important to look at the system as a whole.

When you operate point-of-use devices at a higher pressure than necessary to perform a certain job or function, you are creating “artificial demand”. This results in excess air volume being consumed, increasing the amount of energy being lost to waste. For example, plant personnel or operators increase the supply pressure in an effort to improve the end use devices performance. When there is a leak in the system, the line pressure will actually begin to drop and performance begins to deteriorate in other areas in the plant. This not only puts stress on the existing compressor but it also leads to the false idea that a larger or secondary compressor is needed.

Here’s a quick reference on how operating pressure can directly affect operating cost:


Our Model # 1101 Super Air Nozzle requires 14 SCFM @ 80 PSIG. Based on the average operating cost of $ 0.25 per 1000 SCF used, it would cost $ 0.21 per hour to operate this nozzle. (14 SCFM x $ 0.25 x 60 minutes / 1000 SCF = $ 0.21)

If you were able to use the same Model # 1101 Super Air Nozzle operating at only 40 PSIG, while still achieving the desired end result, the air demand would decrease to only 8.1 SCFM, reducing the hourly cost to $ 0.12.  (8.1 SCFM x $ 0.25 x 60 minute / 1000 SCF = $ 0.12)

Don’t waste your money

Leaks in a compressed air system can account for up to 30% of the total operational cost of the compressor, wasting thousands of dollars of electricity per year. Some of the more common places for a leak to occur would be at connection points such as valves, unions, couplings, fittings, etc.

In this table, you will see that a certain amount of air volume is lost through an orifice or opening. If you have several leaks throughout your facility, it isn’t gong to take long for the waste and high operating costs to quickly add up as well as potential increases in repair or maintenance costs for the existing compressor. The industry average shows that any leakage more than 10%, shows there are areas where operational improvements could be made in a compressed air system.

Stay tuned to our blog over the next few weeks as we will discuss how following a few simple steps can help optimize your current compressed air system, in many cases, reducing energy costs related to compressed air waste, leading to a more economical operation.

In the meantime, if you have any questions or would like to discuss a particular application or EXAIR product, give me a call at 800-903-9247.

Justin Nicholl
Application Engineer
justinnicholl@exair.com
@EXAIR_JN

 

 

 

 

1″ Flat Super Air Nozzle Makes Clean Sweep Of Greasy Chain

Published on by Russ BowmanLeave a comment

A manufacturer of lubrication equipment had a messy problem to solve with a customized system they were designing, to apply grease to a drive chain.  They wanted to clean excess grease off the chain and deposit it into a reclaiming chamber, both to keep the area clean, and to prevent waste.  And because of the corrosive nature of the environment, it had to be stainless steel.  This was a “textbook” application for our Model 1126SS 1″ 316SS Flat Super Air Nozzle.

 

EXAIR’s 1″ Flat Super Air Nozzle is available in Zinc Aluminum or 316SS Construction. The replaceable shim makes it one of our most versatile products.

They also needed to lock it into position, once the exact angle of the air flow was determined, so they incorporated a Model 9052 1/8 NPT SS Swivel Fitting into their design.

When supplied with a Swivel Fitting, the 1″ Flat Super Air Nozzle can be precisely aimed for the most exacting applications.

Now the chain is clean, the grease is reclaimed, and the simplicity of the operation drew a lot of positive attention from the client.

I’ve written about this before, but it bears repeating…EXAIR Corporation’s plan for success is centered on being easy to do business with.  This was a situation where every facet of the project was impacted by our commitment to that goal:

*The customer and I determined the correct product to try in just a few minutes on the phone.

*The order shipped out, same day.

*The attention to detail that Engineering and Production put into the development of this product became evident in the ease of installation and operation.

From the moment you contact EXAIR, to the moment you achieve success in your application, it’s our job to make sure you get the most out of our products. If you have a job that you think one of our products might be a good fit for, give me a call.

What Is The Difference Between Pressure & Flow In A Compressed Air System?

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There is rarely a day that goes by that I don’t receive a call from someone who has a need for a compressed air product and when I state the SCFM requirements of the device they respond back with the psi rating of their air compressor.  Many technicians simply do not understand the difference between the two.  Simply put psi (pounds square inch) is force and CFM (cubic feet per minute) is flow.

A simple illustration would be to contrast a 12 VDC powered air compressor that many people carry in their trunks to inflate car tires.  They will inflate your car tire to 35 psi in a matter of minutes.  While the air compressor at a tire shop can inflate a car tire in a minute or less.  What is the difference?

12 VDC Air Compressor
12 VDC Tire Inflator

 

Simply put, the flow. Both inflate the tire to the desired pressure but the one with largest flow (volume) does it much faster.  In the case of a compressed air product such as an air nozzle, the pressure required to operate is only one part of what is necessary to operate the device effectively, you need to have enough flow or CFM.

Let us now consider an EXAIR 1100 Super Air Nozzle, its rated performance of 13 ounces of force at 12″ distance from the nozzle is derived from supplying 14 SCFM @ 80 psi.  The typical home use air compressor that runs on 110 VAC (Generally 2 HP maximum) will not generate the flow (volume /CFM) at 80 psi to run the nozzle at peak force, just as it would not generate enough flow to fill the tire as quickly as the industrial compressor at a tire shop.

When an open tube, pipe or inefficient nozzle is placed at the end of an air line to provide blow off for cooling or cleaning it demands much greater volume from the compressor. If the compressor cannot keep up the force (pressure) of the system will decline. Replacing an open tube or pipe with an EXAIR engineered nozzle will require less compressed air volume which, in turn, will give the compressor more ability to provide full pressure and force upon your application.

1100group
EXAIR 1100 Super Air Nozzle

If you would like to discuss air consumption of any of EXAIR’s engineered solutions, I would enjoy hearing from you…give me a call.

Steve Harrison
Application Engineer
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12 VDC Tire Inflator Image courtesy of Moto Service Dinamarca