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.
- Check the Air Supply
Check the plumbing
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.
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.