Additional Benefits To The Adjustable E-Vac Vacuum Generators

The EXAIR Adjustable E-Vacs are available in 4 different sizes to fit whatever your pick and place, vacuum holding, degassing, or vacuum evacuation process may call for. These units have been used in a multitude of applications and the Adjustable factor makes them versatile enough to fit a production line with changing needs.

These are all examples of how an E-Vac pick-and-place system is just a solenoid valve away from automation.

The Adjustable E-Vacs have a few benefits that may go unnoticed if one is not keen to exactly how they are constructed and function. This sets them apart from many vacuum generators. When dealing with vacuum generator applications such as pick and place, having a part that is always the same is easiest. This is not always the case. Sometimes it is not just the dimensions of the part that changes, sometimes the material changes or even the surface finish of the part. This is where the ability to change from a porous to non-porous vacuum generator is extremely helpful. Generally this means the material of the parts getting picked up will allow air flow through them (paper, cardboard, wood) or not (plastic, glass). A porous vacuum generator will pull more flow through the part material to hold the vacuum, a non-porous vacuum generator will pull less flow and achieve higher vacuum levels.

To better understand the difference between porous and non-porous, we’ve written about that. Check out Tyler Daniel’s blog on the difference between the two here. The beauty of the Adjustable E-Vac is that it can easily convert from porous to non-porous with a simple adjustment. This is a great feature for a job shop that may change materials they are cutting or engraving on their machines and need to adapt in a moments notice for the job at hand. This could also reduce the number of vacuum generator variances a store room may need to keep on hand for a series of production lines and help to reduce the chance an incorrect model is installed on a machine due to fewer variants.

Adjustable E-Vac

Another benefit which can be helpful in a production environment that has an E-Vac picking up dirty or debris ridden material is that the Adjustable E-Vacs can be disassembled and cleaned. Picking steel sheets off a laser cutter in order to remove the scrap that has a volume of spatter / dust can cause an accumulation of debris on the internals of any vacuum generator. By unscrewing the plug from the body the Adjustable E-Vac can be easily cleaned and all passageways maintained at a level to offer continual performance.

No matter what, the adjustability coupled with minimum components and fastener free disassembly of the unit are two great features that can help minimize machine downtime, lower number of parts kept on hand for machines, and ensure optimal performance no matter what the requirement is for the vacuum generator. If you would like to discuss further, please contact us.

Brian Farno
Application Engineer
@EXAIR_BF
BrianFarno@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