Troubleshooting 101: Super Air Knife

Yesterday, I was working with a customer on troubleshooting a Super Air Knife. He had brought the knife into EXAIR’s demo room so I was able to verify a few items very easily.  When trouble shooting air knives there are no moving parts, so it is very small list of items to check.

  1. Check the Air Supply

  2. Check the plumbing

  3. Check the inside of the Air Knife for debris

The customer had a 36″ Super Air Knife ,and he was seeing some weak spots in the air flow as well as a gradient in flow from one side of the knife to the other.  The first thing I did was to install a pipe tee with a pressure gauge in both ports on the bottom of the knife.  This would allow me to monitor the pressure we were supplying to the knife to calculate the air consumption and ensure the our piping was not starving the knife for air.

IMG_3735

Feeding the knife with equal pressure from both sides, is necessary for any air knife 24 inches or longer. The customer immediately noticed that the flow from the knife lost any sort of gradient, once it was fed in (2) locations. Still the air knife exhibited a spot in the flow where air velocity significantly decreased.  Since we were getting correct pressure and supplying enough air, we decided to remove the cap from the Super Air Knife.  Under the cap we found a variety of debris and one dreaded piece of PTFE plumbing tape. The plumbing tape was suppose to prevent air leaks throughout the compressed air system, but a piece had become lodged in the air gap of the Super Air Knife preventing air flow through a small portion of the Super Air Knife.  As you can see, once we followed a few simple steps to ensure proper installation of the Super Air Knife, it was quick and easy to narrow down what caused the lack of performance. This is yet another reason to make sure you have clean and dry compressed air, as well as use a point of use filter separator.

Dave Woerner
Application Engineer
Davewoerner@EXAIR.com
@EXAIR_DW

Where Would You Use a Large Stainless Steel Nozzle and Why?

This is a question that we are sometimes asked by clients who look at our complete Air Nozzle range and see that we have everything from the tiniest M4 nozzle up to some really large ones that fit a 1-1/4” steel pipe. So, what would you use model 1114SS for anyway?

I just so happen to have a perfect scenario for you as described below.

A recent customer inquired with me about some method to blow off large diameter electrode holders for a furnace application. For those of you who do not know, furnaces used to smelt aluminum, zinc, steel and other alloys tend to be very hot and dirty places.

Furnace

Being as such, a lot of debris tends to collect on horizontal surfaces including those of the electrode holders themselves.

electrode holder

What happens is dirt and dust are building up on the top of the holder and when it is opened it is becoming trapped between the holder and electrode causing arcing to go on inside the holder. The environment the solution will need to work in runs about 1500 – 1600°F. The area immediately around these holders is even hotter. So any nozzle placed in that environment will need to be able to withstand that temperature.

The solution: (3) model 1114SS (1 NPT Stainless Steel Super Air Nozzles) are placed in a triangular configuration to blow all the debris off of the top surface of the holder and electrode prior to opening to completely eliminate the arcing problem that had been occurring.

The key to the solution was to have an effective force generating nozzle that could project maximum force at distances well over 2 meters from a target and do so in a very hot application.

So, now you have one very good idea of how and where the larger Stainless Steel Super Air Nozzles can be used.

Neal Raker, Application Engineer
nealraker@exair.com