4x40 mes membrane not much permature

[mitty440]

Hello
I built a 4x40 ro unit with fluid o tec 250 pump on a 3/4 horsepower motor. I can build good pressure put it doesn't seem like I get much permeate out. Last night I ran thru 240 gallons of sap and only got out 75 gallons of permeate. Does anybody have any idea what could be wrong.
Thanks

[Bricklayer]

With my single MES membrane running at 225 psi and 39-40 F degree sap I max out at 1 gpm of permeate and I run the concentrate at 0.5 gpm.
Depending on your sap temperature you will get different results. The rejection rate goes down with colder sap.
Do you have a recirc loop?
Flowmeters.
And as the membrane gets more sap through it it gets less efficient.
I found after 750-1000 gallons processed it needs a good soap wash.

[mitty440]

I have a recirc loop with no pump. I have flow meters and it was set at .6 gpm
There has been about 350 gallons of sap run thru the filters

[Bricklayer]

What pressure are you running it at?0.6 is around what I have mine down to. Usually with cold sap and 225 running pressure it will be just under 1 gpm of permeate flow I’d double check and make sure there are no restrictions on your permeate line and that your membrane is installed right not with the u-cup seal in wrong direction If that is all good. Then I think you are ok.

[mitty440]

The pressure it at 250 psi. Just to make sure I have the u cup right I have it on the feed side of membrane and the bigger part of the o ring towards the feed side. If this correct?

[wmick]

Yep - Ring should be at the end of your membrane where the sap enters....
Can you take any photos of your setup?
How long did it take to run through your 240 gallons? (trying to get an idea of your flows per hour... permeate, concentrate and recirc.)

[Bricklayer]

Are you running all 1/2” lines ? We need as much info as possible to help you out.
Good thing is you are getting permeate. So it is working.
Give us some pictures of as much as you can.