Concentrate and permeate control

[adk1]

Ran ro for the first time trying to concentrate sap. My permeate side was saying 2 gallons per minute but my concentrate side was maxed out 5 and no matter what I did to the concentrate valve it wouldn't change. I was planning on running it equal parts permeate and concentrate. Any ideas?

[jmayerl]

So what do you have for a RO? Sounds like you need to turn up the pressure

[adk1]

I have a springtech micro elite 160gpm with two 4x40 membranes. I have one valve that screws in and out. Screw it in for more pressure out for less. I had it screwed all the way in And it would increase the pressure on the membrane but the float that I read to try to regulate the gpm would not change it always was maxed out on 5. When I would turn the valve out the membrane pressure gauge would show less pressure but it still didn't do anything to the float gauge that I use to regulate the gpm of concentrate. Maybe this is normal? I have never used an ro and the book is junk.

[maple flats]

That does not sound normal. On my RO, as I crank up the pressure the concentrate flow goes down and the permeate flow goes up. What pressure is your gauge showing when you are running? You likely have 2 gauges, one is a low pressure feed pressure to the high pressure pump, the higher reading gause is the operating pressure. On my RO I generally see about 20-25 PSI on my low pressure and I keep my high pressure gauge at about 270-275. Mine is set to cut off at 300 PSI, yours may be different.

[jmayerl]

First I would say, does it look like it's putting out that much concentrate vs permeate? Second on my deer run which is slightly bigger than your unit, the valve must be nearly turned in. After a few minutes the pressure builds higher on its own, flow slows down, and you need to slowly adjust the valve more open.

Also is there a recirculating valve than might be open. My recirculating valve is a small needle valve before the pump.

[adk1]

Honestly I didn't pay attention to the low pressure gauge only the high. I was running the high pressure gauge at 150-200 as I was monkeying around. The stream of sap coming out of the 3/4" concentrate line was way more than that coming out the permeate line. I believe that I turned all valves as indicated on the pictorial directions unless I missed something

[adk1]

Why is the low pressure gauge so important?

[Flat Lander Sugaring]

con. goes down perm goes up. have you taken sugar readings on con. and perm.? make sure you dont have any sugar in your perm.

[maple flats]

What pressure does your RO instructions say it should run at? On my 250 Deer Run, I think if I ran at 150 PSI the flow may be similar to yours, or at least the concentrate flow would far exceed the permeate. I'll try that to see today. Turn your valve that adjusts the pressure until you show a pressure of about 25-35 PSI under your max. possible. You will see a big difference. If you do not restrict the concentrate flow after the membrane, you will remove very little water. It is the pressure that pushes the water thru the membrane while the sugars can't go thru and they exit as concentrate. Some place there must be an indication as to your max. pressure. Besides my poorly written manual, my gauge only goes up to 300 PSI and a red line starts at 275. The 275 or barely under it is where I run. I control my PSI in 2 ways, 1st, I have a large needle valve just under the concentrate flow meter, that gets set first. I start with it backed off a couple of turns and run until I get the air out and the concentrate reading clears. Then I turn that to 275-280 and I then open a smaller needle valve that is t'd into the concentrate line before the main needle valve, it is my recirculate valve and it runs concentrate back to the high pressure pump at it's inlet. I open that valve a little, then I turn the main needle valve up to 280 and again back off the pressure opening the small needle valve more. I repeat this 3 or 4 times and then I run. At that point depending on sap temperature and clarity, I'll be at about 275 PSI, have a flow of about 1.1-1.2 GPM concentrate and the rest of my 240-260 GPH will be permeate. I run like that and if my head tank gets high enough, I reduce the pressure, close the re-circulation valve and I open the valve on a line from my head tank, close the sap line and by just opening one as I close the other I'm re-concentrating the contents of the tank which had been concentrated already. Once the concentrate hits the RO, the pressure will climb, when it stops climbing, I again urn the main needle valve so I have 270-275 PSI and the little valve stays closed. In this mode I need to check the pressure at each fueling of the fire, because it will slowly climb and need to be backed off every 9-18 minutes (I fuel every 9 minutes).
Try this and see if your results don't get lots better. Being a 160 GPH unit the numbers will be lower, but the results should be similar. You should be able to get more permeate than concentrate but likely not as great of a ratio as 1 part concentrate and 3 parts permeate. Your system likely runs at a lower max. pressure if it has 2- 4x40 membranes.

[halladaymaple]

Just curious Dave. I have a very similar setup that you are describing. Using the method you described... what is your sugar content going in at and what is the sugar content going out at?

[adk1]

15812
What pressure does your RO instructions say it should run at? On my 250 Deer Run, I think if I ran at 150 PSI the flow may be similar to yours, or at least the concentrate flow would far exceed the permeate. I'll try that to see today. Turn your valve that adjusts the pressure until you show a pressure of about 25-35 PSI under your max. possible. You will see a big difference. If you do not restrict the concentrate flow after the membrane, you will remove very little water. It is the pressure that pushes the water thru the membrane while the sugars can't go thru and they exit as concentrate. Some place there must be an indication as to your max. pressure. Besides my poorly written manual, my gauge only goes up to 300 PSI and a red line starts at 275. The 275 or barely under it is where I run. I control my PSI in 2 ways, 1st, I have a large needle valve just under the concentrate flow meter, that gets set first. I start with it backed off a couple of turns and run until I get the air out and the concentrate reading clears. Then I turn that to 275-280 and I then open a smaller needle valve that is t'd into the concentrate line before the main needle valve, it is my recirculate valve and it runs concentrate back to the high pressure pump at it's inlet. I open that valve a little, then I turn the main needle valve up to 280 and again back off the pressure opening the small needle valve more. I repeat this 3 or 4 times and then I run. At that point depending on sap temperature and clarity, I'll be at about 275 PSI, have a flow of about 1.1-1.2 GPM concentrate and the rest of my 240-260 GPH will be permeate. I run like that and if my head tank gets high enough, I reduce the pressure, close the re-circulation valve and I open the valve on a line from my head tank, close the sap line and by just opening one as I close the other I'm re-concentrating the contents of the tank which had been concentrated already. Once the concentrate hits the RO, the pressure will climb, when it stops climbing, I again urn the main needle valve so I have 270-275 PSI and the little valve stays closed. In this mode I need to check the pressure at each fueling of the fire, because it will slowly climb and need to be backed off every 9-18 minutes (I fuel every 9 minutes).
Try this and see if your results don't get lots better. Being a 160 GPH unit the numbers will be lower, but the results should be similar. You should be able to get more permeate than concentrate but likely not as great of a ratio as 1 part concentrate and 3 parts permeate. Your system likely runs at a lower max. pressure if it has 2- 4x40 membranes. I was only adjusting one valve called the V2 valve that would regulate the pressure on the membrane dial gauge. See pic. also, my 4x40 membranes are Airablo Hydranautics PVD1

[GeneralStark]

In your photo there is a stainless valve on the stainless manifold on the left side of photo. The ball valve with two blue high pressure lines coming out of the bottom of it. What are you doing with that valve while concentrating? It should be closed when concentrating and open when rinsing or washing.

According to the instructions this valve I am referring to is labeled as V1.

http://www.leaderevaporator.com/pdf_files/springtech_80_gph_manual.pdf

Also, what does the membrane pressure gauge read up to? After a quick glance at the manual I don't see what they recommend for max pressure but the examples they provide suggest you could be concentrating at 450 psi.

[maple flats]

If I run 2% sap in I get about 7.9-8.1% out. Unfiortunately this year the sugar has been the lowest I've ever had. What I ran today was only 1.4%. This year I have had 1 day only at 1.9%, a few at 1.7 then 1.6, 1.5 and finally 1.4 is my lowest. At 1.4 I can squeeze it enough to get 7-8% but when doing that I have a lot going back thru re-circulate. Then my net flows really suffer. I tried getting 8% and did, but the concentrate was only at 0.6 GPM and the permeate was 1.9% and the rest was going the path back to recirculate. I can't boil with that low of a concentrate flow, so I then backed off the pressure a little, closed the re-circulation loop and then I got 2 gpm concentrate and 2.3 gpm permeate. I didn't test the sugar % but I'm guessing it was close to 3%. I far prefer running 2.3-2.8% sap and getting 9-10% concentrate, but not this year. his year has been a sugar% challenge for sure. It would have been impossible without an RO. My wife likes the 45% RO but neither of us even dare get a price.

[adk1]

Sugarman3 stopped by tonight and got the ro all straightened out for me. Before long I was concentrating 2% sap to 8% sap. Can't thank him enough! Filled my 130 gallon permeate tank for a rinse cycle. Love it!

[wiam]

What was wrong?

[adk1]

Operator inexperience. I thought that I was had increased the pressure on the membrane to the max when actually the valve was simply sticky (sugared over) and you really had to crank on it to work. I need to remove it and run it under some hot water for while. So I basically was not putting enough pressure on the membrane etc. Like I said, operator inexperience.