Acceptable Sugar Passage and running the RO?

[danno]

I knew I needed to buy new membranes when I purchased this used unit, but just curious what acceptable sugar passage in your permeate is? On a refractometer, I'm passing about .5% sugar.

The RO did not come with a manual - so I'm just following the prior owners instructions and running the high pressure pump at 380 and washing/rinsing at about 225. Does that sound about right?

Would I pass less sugar on these old membranes if I ran the high pressure higher/lower? Ran the concentrate sweeter/less sweet?

[Russell Lampron]

.5% is quite a bit of sugar passage. If your sap is only 1% to start with 1/2 of your sugar is going into your permeate tank. Try running it at 200 psi or less with a higher concentrate flow.

Are you concentrating in one pass or recirculating? If recirculating the higher the concentrate flow the better. Increase it until your permeate flow drops off. Even it out for the best permeate flow at that point.

[brookledge]

I agree with Russ that is too high. Get your membrane checked.
Looking at your signature you say you are doubling your taps this yr from 400. So say you get 10 days at a gal of sap/tap. That is 8,000 gallons of sap and at .5%=172 to one for a ratio. 8,000/172=46 gal of syrup. 46 gal of syrup times say $50 per gallon=$2,300.
For that price you could have bought 2 new membranes and still have money left.
Keith

[Russell Lampron]

Kieth I just bought a new NF270-4040 4" membrane for my RO for $408 including the $96 overnight shipping charge. For what it has done for my RO it was money well spent. Two of them would be $624 plus shipping.

[brookledge]

That was the point I was trying to make. My 8" was around $800 delivered.
If they are passing .5% that is alot of syrup being wasted
Keith

[Russell Lampron]

Yes that was my point too. A new membrane or 2 would be far less expensive than the value of the syrup that could be made from the sugar in the permeate.

[sfsshadow]

check the 0 rings at the bottom and top of the membrain.if they are cracked or not seating perfect,they will pass sugar

[danno]

These membranes are so old, I'm not going to even tell you how old ...

The previous owner told me they were passing some sugar but I thought I'd get the hang of the machine this year - guess I should have made the move rather than waiting.

What is an acceptable sugar passage - .01, more, less?

I need 4 4". Russ, where did you buy yours?

[sapman]

Keith, which membrane did you get? NF270? How's the flow, and any sugar passage with it?

[sfsshadow]

These membranes are so old, I'm not going to even tell you how old ...

The previous owner told me they were passing some sugar but I thought I'd get the hang of the machine this year - guess I should have made the move rather than waiting.

What is an acceptable sugar passage - .01, more, less?

I need 4 4". Russ, where did you buy yours?

.01 is unacceptable, it should be 0%. Also check for cracks in membrane itself. It can actually be fixed by using plumbers glue.

[Russell Lampron]

Danno, I got my membrane from Atlantic RO. The web address is www.formembranes.com and Joe is a super guy to talk to and do business with. I had my debit card out, ready to give him the numbers, when he said that the invoice will be in the box with the membrane and to send him a check.

I got the NF270-4040 and am very pleased with it. It flows very fast and doesn't pass any sugar at the low pressures that I am running it at. There is a disclaimer that says that it will pass some at higher concentration levels. So far mine hasn't even at 22% concentration.

[brookledge]

Tim
I went with the NF270 and I got it from Joe at Atlantic like Russ did. I ordered it and it was here in a few days. I have been running it through one time and concentrating up to the low 9's. The RO is a 600gph but it has been running over 700 and the permeate test 0%
It is the perfict size for my evaporator I start them together and when the RO is out of sap it is about time to shut down the evaporator
Keith

[danno]

Well, I spoke with Joe - I'm gonna wait till next season to put in the new membranes. Got to pull out an old one and make sure the new ones will fit or whether I need the adapter and then wait for delivery and reinstall, yadda, yadda. Just would not have them installed in enough time to make it worth it for this season.

But there's more than one way to fry an egg. If you guys can re-circ your concentrate, why can't I re-circ my permeate. I've got my permeate going back through now - sap passage is just a shade over zero, and the concentrate is about 3.5%. If I don't recirc again, I'll be using the RO to give me roadside tree sweetness. Still beats the heck out of boiling .5% sap, and now I'm losing almost no sugar. I feel better now.

[arcticmaple8]

I have been researching membranes pretty heavy and the best prices i have found are from www.midwestro.com. I called a guy named joe who is the expert on membranes, he was very informational. A nf 90 or 270 - 4040 is 312 plus shipping. Joe was telling me that they make a nf 270 xle which is slightly tighter than a plain 270 therefore more resistant to passing sugar but still has a better flow than a 90, similar to the 270. I dont know the price difference on the 4" but i was looking at the 8" and an xle was cheaper than a standard, which is probably the reason he sells twice as many xle's. Also if you have a mark 1 membrane currently it is the same membrane as a nf 90 except the center tube on a mark 1 is 1-1/8" diameter where a standard nf90 is 1-1/2". Midwest makes adapters for about $55 to overcome this so you can buy the cheaper membrane instead of the one marked up buy the r.o. manufactures. Anyhow joe is on the east coast and is open until 6pm his phone number is (910)457-9336 good luck

Just realized that atlantic ro and midwest ro are same company just two different locations

[Russell Lampron]

Actually there are 3 locations. There is a PacificRO in California as well. These people know membranes and are very nice to deal with. The guys are brothers.