RO experience with possible expected yield with my RO

[vtbackyardmaple]

Hi everyone,
I have the aquatech 8852 paired with 4x150gpd membranes.
About this item

Aquatec CDP 8800 pressure boost pump
8852 model is higher flow than 8851 version
For boost the water supply pressure for RO reverse osmosis water systems
Use for 100GPD to 200GPD RO systems and some misting systems
I did find this chart:
http://www.aquatec.com/documents/downloads/8800%20Series%2024VAC%202.6%20LPM.pdf
it looks like at 100psi I'll get about .21gpm

Plan on running it 100-110psi.
Any idea potentially on what yield I should be looking at as gph of concentrate? Is there a formula for that?
50%/50% is what I'll probably set it at with valves.
If I get .1 gal per min of concentrate that would be 1 gal every 10min
6 gal per hour? I don't think my math is right.
HELP!
Thanks.

[DRoseum]

I ran an RO with that exact same pump but using 400 gpd membranes for the past 2 years.

Your pump flow rate might be a bit higher at 100 psi (membranes are rated at 100 psi). More like .26 gph which would be ~15.6 gph in and at 50/50 yield 7.8 gph concentrate. However, your membranes will only produce 6.25 gph of concentrate under perfect conditions (150/24 = 6.25), which is based on their spec at a higher water temp (normally 70F). In reality with 35 - 40 F sap, that will be lower, maybe 80% of it... so 6.25x0.8 = 5 gph.

This year I am switching out the pump for a much higher flow rate at 100 psi and increasing to 4 x 400 gph membranes to increase concentration and yield.

[vtbackyardmaple]

Okay-let's take the 5gph x 12 (overnight say 7pm to 7am) 60 gal of concentrate and 60 gal of perm. 120 gal of sap. I'll never collect that much in a day. So, this will be a good setup theoretically.

Thanks.

[vtbackyardmaple]

my ro membranes can run at 150 psi.

The Axeon TF-series membrane elements offer high quality water for residential use. The TF-series will fit standard 2 x 12 RO membrane housings and have an indefinite shelf life. These are highest performing membrane elements that deliver consistent quality and performance. TF-series residential reverse osmosis polyamide-thin film composite membranes offer reliability, high performance and deliver consistent results for higher quality water. 98 percent nominal salt rejection. Improved system performance. Superior quality and cost savings. Individually vacuum tested. Axeon residential membranes operate as low as 50 psi and can yield up to 23 percent more water than other membranes at 65 psi. This Membrane Element is Tested and Certified by NSF International against NSF/ANSI Standard 58 for material requirements only. 150 gpd permeate flow rate. 98.00 percent stabilized salt rejection. 50 psig supplied pressure. 113 degree F maximum operating temperature. 150 psi maximum operating pressure. 2 gpm maximum feed flow rate. 2-11 pH Range, continuous operation

[maple flats]

I don't know about those membranes, but with my 250 gph and 275 psi I could never run for 7 hrs non stop reconcentrating. AS the membranes begin to get coated, the flow slows unless they are flushed. I do that be watching the pressure. Early in the season I might run about 1-2 hrs and the RO will shut off on high pressure (300 psi). If I didn't notice before that, I then need to change my source. I close the concentrate hose valve and open the permeate hose valve. I run it like that for up to 5 minutes to flush the membrane, then switch back to re-concentrating. Later in the season I might only get half that time. That seems to vary season to season.

[vtbackyardmaple]

So maybe I start the ro first thing when i wake up and get my coacoa going and when i get about 10 gal start boiling and put the concentrate right into my heater pan... hmmm... not a bad idea.
another thing I might do is test concentrate at 70 psi, then 80, then 90, then 100 and see if the concentrate goes up significantly. I'd be happy to stop at 80 psi if it'll process 8%. My sap comes in about 3.5%. My lowest was 2.9 and highest 4.05. Not sure why the flux with brix sap as were the exact same trees. Strange to say the least, but nature is what she does.

[SDdave]

So maybe I start the ro first thing when i wake up and get my coacoa going and when i get about 10 gal start boiling and put the concentrate right into my heater pan... hmmm... not a bad idea.
another thing I might do is test concentrate at 70 psi, then 80, then 90, then 100 and see if the concentrate goes up significantly. I'd be happy to stop at 80 psi if it'll process 8%. My sap comes in about 3.5%. My lowest was 2.9 and highest 4.05. Not sure why the flux with brix sap as were the exact same trees. Strange to say the least, but nature is what she does.

That's about what I do as well (except I start the RO then get dinner ready for the kids, etc. then start boiling). I have had those filters, if memory is correct, the sweet spot was/is at 125 PSI. With sap at 3.5% it'll get your 50/50 ratio. Pushing it to 8% and slightly higher will compound fouling membranes. With cold sap it would process 10 gallons in about an hour. Don't forget to flush/wash cycles for the membranes! Keep us posted on the new addition!

SDdave

[DrTimPerkins]

Don't forget to flush/wash cycles for the membranes! Keep us posted on the new addition!

Make that a flush/wash/rinse cycle. Always rinse with permeate after a wash. With the "flush" part, you can collect the concentrate, but it will steadily drop in Brix.

So really you have two choices.

Concentrate/flush/concentrate OR, if flow rates drop too low then you'd do a Concentrate/flush/wash/rinse/concentrate cycle.

[vtbackyardmaple]

Tim-Keep in mind my biggest collection for a day has been 40 gal of sap.
If it's cold enough I'll wait until my 65gal bin is full and start processing.
I have one 35 gal bin and I'm thinking I really need one more - concentrate and perm after ro.

I've looked around and I see citric acid and rince. What do you 'wash' with?
You're the expert here so I would like to know before I start boiling.
On the manufacturers website they have some sort of entrapment of professional flushing system-which I clearly don't need.
My thoughts were to run perm 5 gal/luke warm water/wash-whatever this is/warm water/perm again. Total estimated volume of my system is 1.2 gal. Run 5 gal would be a decent flush, 5 gal luke warm, wash,5 gal luke warm, 10 gal perm or more.
Does this sound correct or am I going too far with this process?