RO plugging - Can I use a strainer?

[OGEngin]

I am in a situtuation where I need to install an RO into my pipeline to protect the downstream piping. The problem is that RO size needs to be 2 mm and therefore it might get plugged at some point. Does anyone have any experience of using a strainer upstream an RO to prevent the plugging? How should I size the strainer?

Thanks for your help!

 

[sshep]

OGEngin

Installing an upstream strainer is common. If you haven't seen it before for an installed RO as per your application, then you have surely seen it for other equipment that uses small orifi (steam and freeze traps, pump seal flushes, small bore rotometers etc). Typically a Y-strainer is used for a small line as it apears you may have.

The orifice bore can be used as your basis for sizing the mesh. As example, a mesh opening of 0.14mm should remove anything smaller than 0.2mm via formula: (partical size retained)^2 = 2*(mesh opening)^2, this assumes the minimum size partical passing equals the hypotenuse of a square with side equal to the mesh opening.

best wishes,
sshep

 

[shahyar]

sshep,
Do you have a ref. for your formula?
I usually use this formula:
(partical size retained) = (mesh opening)*3/2 (with ref.)
Just I am curious.
Thanks

 

[sshep]

Hello shahyar,

I think the spirax sarco website has this strainer sizing formula, but it is basically the opposite corner distance for a square of with side equal to the mesh opening. The ultimate reference would be Pythagoras: a^2+b^2=c^2. At least it is easy to understand the reasoning. Of course we always filter to smaller than actually needed because of odd shaped particals (needles shaped) oriented such that some make it through the mesh but then hang up elsewhere.

best wishes always,
Sean