Fabricating a Vacuum Pump Air Filter - Part One

Part Two: • Fabricating a Vacuum P...
Part Three: • fabricating a vacuum p...
If you use your Freeze Dryer as a vacuum Packer you may notice it is harder to keep you vacuum pump clean. In this video, part one of three, I will explain the concept of an inline vacuum filter and what you need to consider when using one. I have also engineered a Filter specifically designed for filtering vacuum pump process air that can stand up to the rigors of external high pressures associated with the vacuum produced by a Freeze Dryer.

[@katzenaugen2]

thank you for doing these great videos!

[@beardpapa7306]

I have the premiere pump and I run 10 to 12 batches before I change the oil and I’ve never had oil come out that dark.

[@evanrowell5266]

As I stated in the beginning of the video unless you use your FD as a vacuum packer this filter is not likely to be needed. It is the dried food dust inside the Mylar bags that gets sucked into the pump along with the air being evacuated from the bag. Thanks, Evan

[@kalsprite]

What is the BOM cost? I had looked at commercial vacuum filters from McMaster Carr, they're ~$500 so i didn't pursue them.

[@evanrowell5266]

This unit cost me about $125. Evan

[@michaelokasinski4325]

If it’s just used for vacuum bagging I’d think making an adapter that attaches something like a kn reusable filter to the vacuum port in the chamber would work fine. I haven’t tried that so if there were reasons to avoid I’d be interested to learn more. Thanks.

[@evanrowell5266]

Hello Michael, What you are saying is true, there are a lot of different methods that might be incorporated to filter the air if air flow was not a consideration. Whatever filter you use it must allow the vacuum to get down to below 400 MT. My first attempt was to just put a cotton cloth very lightly into the vacuum port inside the chamber but even that little bit of résistance prevented my vacuum from getting below 2300 MT. The unit I designed in this video effectively filters out the particulate without opposing air flow and that is a critical consideration. Thanks for the comment, Evan

[@KayKirkpatrick]

Which version of vacuum pump are you using with your freeze dryer?

[@evanrowell5266]

I have both the oil free pump and the standard oil filled pump. unrestrained particulate flow can damage the oil free pump shortening its life considerably. As I stated in the beginning of the video unless you use your FD as a vacuum packer this filter is not likely to be needed. It is the dried food dust inside the Mylar bags that gets sucked into the pump along with the air being evacuated from the bag. Thanks, Evan