Hi,

I have a DOTpro 320 A2B2E2K2P3 RD screw in filter.

Might anyone know if it will filter viruses when airflow is reversed? I.e.from the screw-side to the non-screw opening?

Thanks!

We are working on a cutting-edge life-saving filtration machine with immediate relevance for certain at-risk groups. As we are trying to roll things out ASAP, our manufacturing process can be drastically simplified if we can hold the filters in a specific way, with the screw in the reverse direction of flow. I know this all sounds weird, but our teams are highly innovative, and this type of thinking has already had us push out new types of ventilators, already clinically tested, based on existing unrelated parts.

Indeed, filters are tested in a specific direction. As this specific filter is wide spectrum, different parts of the spectrum are filtered by different mechanisms within the filter. I am sure that certain mechanisms are, by design, one way. But I am specifically asking about the section which relates to biological filtration. Obviously the filter would not have been tested this way - but understanding the physics of the filtration will suffice - hence my query.

As for viral droplet size filtration, you can have a look at the filter spec. It does, albeit not 100%, filter what is usually termed an aerosol micron size, which is less than the droplet size usually associated in the literature with coughing and sneezing (these terms are difficult to relate to - coughs and sneezes output an entire size range - and aspects of turbulence etc. have an effect... A good overview can be found in the Bourouiba paper on JAMA).  The above filter would, in general, be comparable to an N99. It is already being used in hospital settings treating contagious patients, with success (yup, med teams not having the right equipment is our reality, but these things work...).

Again, I know the question is weird, but any input from anyone who is aware of the physical construction of the filter would be most appreciated. The manufacturer is, well, difficult to get a hold of.

Thanks again.

Peter,

I had the pleasure of working in London for a few weeks on HMS President 1918 docked under Blackfriars Bridge right when Saddam Hussein thought he could take Kuwait. In all the craziness, I'd met several groups of people, doing the most oddball of things (like resurrecting a working PDP11). Over the years I'd return to those groups, asking them to solve all sorts of quirky things I had in my bag. Kinda worked every time:) So posting on this forum still has me hoping that someone can see through ANSI whatnot and give an opinion as best they can :) (ANSI = IOSH something, no? :) )

And part of my team is at the forefront of ERs. They are former combat pilots. We are at war. We need solutions. We promise to fill out all the forms, in retrospect, in 2023.