View Single Post
  #10   Report Post  
Glenn Ashmore
 
Posts: n/a
Default New higher capacity ro watermaker membranes available from DowFilmtec - needs pump design changes?

That is not physically possible. THe best you can do is minimize it.
It takes almost 2 psi to push half gallon a minute through the 1/4"
fitting at the end of the pressure vessel. Beyond that you have the
flow meter, diverter valve and piping. Not to mention the hose to the
tanks. About the best you can expect is 5 or 6 PSI total. High volume
commercial systems run 10 to 15 psi on the product side. The important
thing is the difference in pressure between the brine and the product
side.

wrote:

They say you're not allowed to have any product/permeate side back
pressure. Was prob the case on the older version as well.


On Tue, 28 Oct 2003 19:18:41 -0500, Glenn Ashmore
wrote:


Ah, I see. They raised it about 20% from .4 to .48 gpm. I will have to
update my Rosa program and see how that will effect my flow. I have
everything built but will not buy the membranes until the boat is
launched. It would have to be compatable because there are to many
systems out there tuned for the old product rate. I can see one thing
that I do need to check. I sized the diverter solenoid for .6 gpm at 5
psi. If it puts out much more the product side back pressure is going
to rise and I will have to up the pump pressure to compensate.

Baja-Mo wrote:


the 2540 page with 700 gpd is here -

http://www.dow.com/liquidseps/pc/jum...c/sw302540.htm

they've improved the line and not told the world so the mfg can clean
out old inventory - same old story





--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com