High Vacuum (Non-porous) and Low Vacuum (Porous) E-Vacs: Vacuum Generator Overview

In-Line E-Vac

With the amount of energy in compressed air, EXAIR can manipulate it by design for a variety of applications. One way that we can do this is by creating a vacuum pressure by the Venturi effect. By increasing the velocity of air through a constricted area, a low pressure, or vacuum, is created. Unlike a mechanical vacuum pump, the E-Vac does not have any moving parts or motors to wear. This maintenance free device uses only compressed air to generate a powerful vacuum pressure in a very compact and lightweight design. They can create vacuum levels up to 27” Hg (91 kPa) where complete vacuum is at 29.92” Hg (101.4 kPa). With our single stage systems, we can generate different vacuum levels and flows to create the optimal vacuum generation for your application.

Have you ever placed your hand over the hose of a vacuum? You can feel the maximum amount of vacuum pressure on your hand. The maximum vacuum pressure value is only at the condition of zero air flow. When you remove your hand from the hose, you change the vacuum pressure to a much lower value, but now you have the maximum amount of air flow. Like the E-Vacs, EXAIR has designed the product to either give you the maximum vacuum pressure or the maximum vacuum air flow. EXAIR separates these two vacuum generators as High Vacuum and Low Vacuum.

The high vacuum style is designed for non-porous products like glass, marble, and steel sheets. The low vacuum style is for porous products like cardboard, fabric, and plywood. Both types of vacuum generators are commonly used to pick and place parts, open bags, evacuate molds, and vacuum forming. They are easily adjusted by a regulator and a solenoid valve making the E-Vac very versatile. Even with no moving parts, these vacuum generators are quick to respond with very long cycle rates. The inline design makes them easy to install, so, you can begin using this vacuum product without much setup time. With the single stage design, it eliminates any vacuum fluctuation. I will go through both types of E-Vacs to explain the advantages in using these kinds of vacuum generators for different applications.

The High Vacuum Generator is used for non-porous products in pick and place applications as well as vacuum forming, clamping, and evacuation. This type of generator can create a vacuum pressure up to 27” Hg (91 kPa). In conjunction with the EXAIR vacuum cups, it allows for maximum holding capacity for heavy materials. We offer 7 different sizes ranging from 2 SCFM (65 SLPM) to 31 SCFM (872 SLPM) at 80 PSIG (5.5 Bar). They can be matched to the size and quantity of vacuum cups for increased efficiency as well as for improved cycle rates. If the surface of a rigid sheet is smooth or the application requires a high vacuum pressure, the High Vacuum E-Vac Generator would be the best product to use.

The Low Vacuum Generator is used for porous products as well as more delicate surfaces. This generator has a maximum vacuum pressure of 21” Hg (71 kPa). The design is such to allow for maximum air flow to make up any losses through the material or sealing area. With a regulator, you can control the maximum vacuum level to eliminate dimpling or disfiguring of the surface. Even with fabrics and rough surfaces, the Low Vacuum Generator can still pick up and hold the material. We offer 7 different sizes ranging from 1.5 SCFM (42.5 SLPM) to 17 SCFM (476 SLPM) at 80 PSIG (5.5 Bar). They can also be matched to the size and quantity of vacuum cups as well as to overcome any leakage. If the surface of the product being moved is rough or the surface is very delicate, the Low Vacuum E-Vac Generator would be the best product to use.

EXAIR created a video to show the difference between the E-Vacs as well as a demonstration.

Click Video

For experimentation with the E-Vacs and the vacuum cups, EXAIR offers kits for both types of generators. The standard kit includes four pairs of vacuum cups (matched to the size of the E-Vac), 10 feet (3 m) of poly line, and an assortment of fittings. For the Deluxe kit, it will include the same items in the standard kit, plus an automatic drain filter and a regulator. The E-Vacs are made of a durable 6061 aluminum, but if a different material is required for your application, EXAIR can review this request.

The EXAIR E-Vac offers an efficient, simple, and maintenance free solution to create vacuum. Whether lifting product horizontally or vertically, opening bags, aligning sheets or leak checking, the E-Vac ensures a flexible and reliable way to continuously keep your operation moving. As compared to an electric vacuum pump, these vacuum generators are much smaller, less expensive and much quieter. If you need help in sizing and selecting the correct model, you can contact an Application Engineer at EXAIR.

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

Custom, Flanged Air Amplifier Solves a Fume Evacuation Problem

We blog about this topic quite a bit, and almost every section of our catalog has a page set aside just for special / custom product configurations that have been created by request from many of our customers.

This is the latest and greatest special that I have seen roll through the production area here at EXAIR.   This is a special 4″ 303 Stainless Steel Adjustable Air Amplifier with a 4″ Tri-Clamp flange on the discharge side and a 6″ Tri-Clamp flange on the suction side of the amplifier.

 

This had been an ongoing project with the customer that started with them testing a stock Adjustable Air Amplifier in the application to ensure that the performance would meet their needs.  The application was to boost a low flowing fume exhaust that was causing slow downs in their production line.  Fans and other traditional methods would require maintenance and would wear out.  The stock Adj. Air Amplifiers exceeded their performance needs but did not easily mount into their duct work because they used all standard size tri-clamp fitting in the ducting, so the next step was to see if we could manufacture a Special Adjustable Air Amplifier just for their needs.  The dimensions of the existing Adjustable Air Amplifier came close enough we were able to easily create a Flanged Adjsutable Air Amplifier that would clamp straight into their existing duct work, exceed their performance expectations, help their process, and be ready to ship within a very reasonable lead time.

Like we have said before, if a stock, cataloged, product doesn’t fit your application exactly, contact us and let us find a way to customize and fit the need.

Brian Farno
Application Engineer Manager
BrianFarno@EXAIR.com
@EXAIR_BF

 

Special Air Amplifier? Not A Problem!

This week I worked with two customers that wanted to boost their air flow with an Air Amplifier. One customer ended up going with a Special Air Amplifier. The second customer I ended up pointing to a different product line entirely. Keep reading to find out why.

The first customer needed to boost the exhaust flow through six inch duct.  The six inch duct was an open vent that allowed fumes to slowly escape from a vessel. During normal operation the vessel, was unmanned, so the fumes only need a path to escape, but could linger. The company wanted to do some maintenance work in the area while the machine was in operation. The vent met the necessary requirements for the air flow of the machinery, but left maintenance workers exposed to a variety of fumes while working in the vessel, if the unit was in operation.

The customer was interested in the model 6034 Stainless Steel Air Amplifier. With 0.002″ air gap and 80 PSIG of inlet pressure, the unit will flow 1,200 SCFM of compressed air at the outlet of the Air Amplifier, but the 6034 can be adjusted to much higher flows from there.  The Air Amplifier would easily be able to exhaust the fumes from the area to maintain a safe and comfortable working environment. The problem was mounting the 6034 Adjustable Air Amplifier. The 6034 is designed to be used in free air with the discharge side of the air amplifier connecting to a duct. The suction side of the Air Amplifier is as open as possible to entrain air, but my customer needed to connect the Air Amplifier to the outlet of the vent. We worked with the customer on designing an Air Amplifier to fit the 6″ Flange that they used to connect sections of their duct similar to the Air Amplifier pictured below.

special air amplifier

This special stainless steel flange-mount Air Amplifier was designed for exhausting hot flue gases from a furnace.

My other customer called to move the air inside a heated drying tunnel. The customer uses a process air heater to heat a large drying tunnel. Unfortunately, the air heater created hot air at the entrance of the drying tunnel. By the time the air reached the end of the drying tunnel the temperature was significantly higher at the top of the tunnel as opposed to the bottom from natural convection. To counter this effect the customer wanted to move air from the process heater half way down the tunnel and release the air. In this application, the customer wanted to duct both the inlet and the outlet of an Air Amplifier. The Air Amplifier is not well suited for ducting and you limit the amount of air that the Air Amplifier can entrain by connecting it to a duct.

For this customer, I recommended he use a Line Vac. The Line Vac typically conveys materials, but it will also move a good amount of air.  The customer was going to use heated compressed air and wanted to convey the air from the process heater to the other side of the drying tunnel. Another key benefit to the Line Vac is the discharge and suction side of the units are both the same size.  This makes it extremely easy to install for the customer and is off the shelf, ready to ship.

Two similar applications on the surface that result in different product recommendation. Not every application for an air mover is this complicated, but if you want to talk through your application EXAIR’s application engineer’s will be happy to help.

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com

Priming the Pump

Yesterday, I had the opportunity to talk to a customer who was looking to prime a pump to remove a liquid out of an 8 foot deep tank.  He was pulling in the liquid through 1 1/2″ pipe and wanted to prime the pump in 5 seconds.  This was an interesting application for me, because it had some tangible numbers for the design.  In most applications with the E-Vac Vacuum Generators, a customer needs to lift something heavy and they need the job done fast. Those terms are very subjective, and we have to try and prognosticate what vacuum generator will work for the customer. Yesterday was different, the customer had some really defined limits, and I knew what I needed to do in order to satisfy the application.  The engineer in me was very happy with the situation.

Let’s start with the parameters.  He was looking to lift water 8 feet vertically.  8 feet of water corresponds to 7.06 inches of mercury.  The porous E-Vac can generate vacuum up to 21 inches of mercury and the non-porous E-vacs can generate 27 inches of mercury, so all of the E-Vac models can easily draw the liquid up the 8 feet of piping.  This is where most vacuum generator applications stop, but not this one.  If time is not a concern the 800001 will use the least amount of air (1.5 SCFM @ 80 PSIG of inlet) and get the job done, but how long will it take?

This is where you need to use the evacuation charts, from EXAIR.com. Below are two charts from the “Specs” tab for Inline E-Vacs.

E-Vac porous evacuation time

Non-porous Evacuation time

The 1 1/2″ Pipe that is 8 ft. long has volume of around .1 cubic foot.  We need to generate at least a 7.06 inches of mercury, so we will look at the 9 inches of mercury column. It will take the 810002 17.85 seconds to evacuate 1 cubic foot of pipe.  The 800001 will take 14.40 seconds to evacuate the same volume, and  it will use less air.  We will want to use the porous vacuum generator, because we don’t need a very high vacuum to get the job done. If the 800001 can evacuate 1 cubic foot in 14.40 seconds it should be able to evacuate .1 cubic foot in 1.44 seconds which is easily fast enough for the customer.  The math also told us the customer could use up to 27.7 feet of hose to lift up that 8 feet, if he needed to take a non linear path.  If we know that the customer needed to move the fluid more that 27.7 feet, we could move up to the next vacuum generator to get the job done faster, but it was not necessary in this application.

Dave Woerner
Application Engineer
Davewoerner@EXAIR.com
@EXAIR_DW

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