Air Knives – What Are They Good For?

It is rare that a week goes by without a unique application of an EXAIR product…

This week I was speaking with a DJ who wished to use an air knife to create a blast of air that would add emphasis to the musical experience had by his fans. He wanted a small burst of air that would last less than a second, but would add an additional element to an already very complicated setup. My initial reaction was that no DJ I have ever seen would possibly be able to supply an air compressor big enough to feed the air knives, but over the course of our conversation, I found out that the DJ travels with 2 semi trucks of equipment, so he had some space.

SAK
An Aluminum EXAIR Super Air Knife

Another topic that came up in our conversation was how air knives were generally used. I have been asked this in a number of ways: What are they designed to do? Where do they work best? or What are they for?

I never have a succinct answer… The air knives create a flat laminar sheet of air in various sizes from 3″ up to 108″. This laminar sheet of air can be used to move, open, float, or separate. It can be used to clean, dry, or cool. I try to categorize these applications as best I can when speaking to customers, but then you talk to a DJ, and he wants an air knife to make a crowd cheer. I never thought that would be an application for an air knife. Knowing this, how do you convey all the air knife can do in a succinct answer?

Well, I can’t, so please be patient when you ask me the same question and I run through applications from cleaning surfaces to entertaining DJ crowds.

Here is a rundown of air knife applications. In case you don’t believe me.

Move: Air Knives are used around to world to move product from a conveyor to another location.

Open: Air Knives uniform air flow is perfect for opening bags or other packaging on a packaging machine.

Float: If you need to bridge a gap between two conveyors, the air knife has done this for products from pizza dough to sheets of veneer.

Clean: Blowing products off after removing them from a CNC machine is an easy air knife application.

Dry: One of my tastiest applications was to use an air knife to blow water from a potato chip after washing, but before frying.

Cool: Extrusion, molds, and baked goods have all been cooled with an air knife.

Just because it isn’t on this list though, doesn’t mean it is not possible.  This is why we will stand behind our stock product with our 30 day guarantee.   So if you want to try an EXAIR Air Knife in your application, give us a call.

30 Day Guarantee
30 Day Guarantee

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com

Floating Plates With Compressed Air

Yesterday, I had the opportunity to work with a customer who was familiar with our product and was looking to roll out EXAIR’s Super Air Nozzle in various parts of the plant. Before purchasing our products, the customer was using (4) open 5/16″ aluminum tubing to move or “float” a 12 inches by 12 inches plate of aluminum. This plate is .187 inches thick and needed to be moved six inches against the wall of their conveyor. The (4) open tubes moved the plate, but the customer had some safety concerns. First, the open pipes violated the OSHA standard 1910.242(b) that any open pipe that can be dead ended must only be pressurized to 30 PSIG. Second, to move the plate successfully the shop pressure needed increase to 100 PSIG which increases the amount of load on the compressor and could lead to higher maintenance in the future. Finally, the noise level of open pipes was well over 110 dBA which was another OSHA violation.

1132ss

Considering all of these problems the customer contacted me, looking for an air nozzle to use instead of the open pipe. After a short discussion we decided to try (3) HP 1125 nozzles. Once the customer installed the air nozzles, they only used 2 of the air nozzles, and they were able to move the plate easily across the conveyor. This netted them several key results. The most noticeable at the plant was how quiet the operation became. Instead of dealing with noise levels in excess of 110 dBa (which is equivalent to the noise level of a turbo-fan aircraft at take off)  the HP1125 comes in at 83 dBA which is roughly the noise of a milling machine.  This was much more pleasant to the operator and any plant passersby.  The most important was the operation now complied with OSHA safety requirement of 1910.242(b).  Because of the width of the Flat Nozzle and the overhang of the cap, the nozzle can not be dead ended.  Since the unit can not be dead ended, pressure above 30 PSIG can be safely used.  Finally, the most economically result was that the air savings for the units.

The 5/16 tube had an ID of .183 and was 18″ long. When supplying it with 100 PSIG of compressed air, it will flow 22.8 SCFM of compressed air, so the customer was using 91.3 SCFM. The HP1125 nozzle uses 37 SCFM at 80 PSIG, so they were able to use 74 SCFM, which means each minute they were using 17.3 fewer cubic feet. At a cost of $0.25 per 1,000 Cubic feet, the HP1125 saved $0.26 per hour or $6.23 per day or $1,557 per year with 250 working days.

Replacing (4) open tubes with (2) HP1125 Flat Super saved $1,557 per year in compressed air savings, an OSHA violation, employees hearing, and lowered the system pressure from 100 psi to 80 psi.  Needless to say the customer was sold on the benefits on our products, and is looking for any more open pipes in his facility.

Dave Woerner
Application Engineer
Davewoerner@EXAIR.com
@EXAIR_DW