ANOTHER homemade RO

[Harken]

19728
Greetings All, thanks for the wealth of info on this site. Just finished my build - 3- 400 gpd membranes, first 2 in parallel, 1 in series. Flushed with water, ready for sap !!

[RedMapleCreek]

Interesting layout. Could you describe the rational for having two membranes parallel in series with a single third membrane. I also have three 400 gpd membranes and ran them all parallel last season but am rethinking there may be a better arrangement.

[Clinkis]

His next door neighbor told him to put them all in series to keep flow rates up but he didn’t listen to him either!

Nice build neighbour!

[Harken]

The design was originally to copy the RO Bucket, 3 in parallel, but then I saw a post from Dr Perkins that
mentioned this layout. I plan to run some sap through it tomorrow , so I’ll see what kind of flow I get. I was just trying to get the most out of the pump and membranes.

[billschi]

This looks like something I can build. Do you have a material list? Thanks for the post.

[Msboucha]

I plan to run some sap through it tomorrow , so I’ll see what kind of flow I get.

What do you typically see for sugar content? You may not have enough flow/pressure with the membranes in parallel to prevent them from fouling. I ran into that myself as we have fairly high sugar. The flow being split between the two membranes was not creating enough turbidity and they would begin slowing down on performance after a short time.

[Harken]

RO is up and running with sap. At 120 psi, i'm getting about .65L/m concentrate and .35L/m permeate. Concentrate is just under 5%. Any suggestions ??

[SDdave]

RO is up and running with sap. At 120 psi, i'm getting about .65L/m concentrate and .35L/m permeate. Concentrate is just under 5%. Any suggestions ??

Start boiling!

Not sure what you wanted for suggestions, but here are a few along with a few notes with your type of setup...if you want a higher concentrate level you should either recirculate or plumb in series. With that in mind these types of RO's max out around 8%. The higher the desired concentration the slower the system processes. Ebb and flow I guess. Your starting sugar content plays a factor here as well, my trees run from 2.6 to 3.2 during the year. I never get above 7% final. What I shoot for is matching output gallons to the speed of evaporation. Maybe not the best allowable performance of the RO, but I relish that my boiling is cut by 45 to 50%.

Have fun!

SDdave

[bawplank]

How much do you have into it? Looks like something I would like to try. Is that the same capacity as the RO bucket that is sold?

[Harken]

It cost me close to $600 CDN ( including taxes and shipping).
Its similar to the RO bucket, just plumbed a bit different.
Ran it today, after a bit of recirculation, had sap up to 6%.

[Msboucha]

RO is up and running with sap. At 120 psi, i'm getting about .65L/m concentrate and .35L/m permeate. Concentrate is just under 5%. Any suggestions ??

Going back to my original comment, I would suggest you try putting all your membranes in series. You could also increase the PSI a bit. I run more like 150psi with 4x400GPD membranes in series and see more like .60 lpm permeate / .20 lpm concentrate. On average I'd say I take the sap from 3 to 9. You start going above 9, and you will see the membranes start to foul and slow down.

[DavidSetness]

I have built a similar system with 150gpd membranes and played with different arrangements. My best and most consistent results came from all three being in series.

[Big_Eddy]

RO is up and running with sap. At 120 psi, i'm getting about .65L/m concentrate and .35L/m permeate. Concentrate is just under 5%. Any suggestions ??

Hmmm - My evap boils at ~16 GPH.

The RO is processing a litre of sap a min or ~16gph as well.
If you start with 100 gallons, run the RO for 6-7 hours and reduce it to 65 gallons - now what was going to be a 7 hour boil become a 4hr boil.
If you light the fire ~ 3 hours after starting the pumps, you should be done at the same time.

And it only gets better if you run in series and the concentration increases.

For $600 invested - sounds like something I'll look into more.