400 gpm RO

[wlatrout]

Last spring someone posted a 3x400 gpm setup. I've searched throughout the forum and have not been able to find it. Does anyone know that post lies?

[maple flats]

Maybe it was 400 gpd, many small homemade RO's use a 400 gal/day membrane single or multiples.

[wlatrout]

Yes it was. It was 2 in series and one in parallel. Maybe another site, can't remember. Seems I use the term a lot these days. I may be senior but at least I'm on the right side of the sod. Gotta be thankful for that.

[maple flats]

Being a senior is not a detriment until the ravages of time take over. At 73, almost 74 I'm hoping to remain sort of OK for a while longer.

[DrTimPerkins]

It was 2 in series and one in parallel.

You probably mean two in parallel feeing another in series. The sap would flows through one of two membranes first (the parallel part), then the concentrate coming out of those membranes would feed the third membrane (which is in series with the first two).

[wlatrout]

Yes, would this be the best use of these membranes? Do you recall an article on how to plum these?

[maple flats]

I don't recall, but the plumbing should be straight forward. First go thru a pre-filter, then route to the first two membranes, using a tee, so the flow can go to either, enter the housings on the outer ports. Then at the exit, have permeate connected to the center ports on each and on the outer port exit join both using a tee and send that flow to the outer port on the third membrane housing. That 3rd one will then have an outer port exit for concentrate and a center port for permeate. All of the permeate lines can be joined using tees and sent to a collection tank. The last concentrate hose (the outer port exit will the need a needle valve of suitable size to match the high pressure pump you are using. In use, get good flow with the needle valve full open, then close it to regulate the flow from each. Many just try for what looks like equal flow from the permeate (the water removed) and the concentrate. Others add flow meters for a better idea of what is happening. Another added item which some add is a pressure gauge on the concentrate line after the last membrane and before the needle valve. Never restrict the permeate flow, just the concentrate.

[DrTimPerkins]

Yes, would this be the best use of these membranes? Do you recall an article on how to plum these?

That depends upon your goals. In general, a single standard membrane will max out at 4.7X the sap concentration at the stated flow rate (400 gpd processing rate I think is what you said, but this is hugely dependent on your pump pressure/recirculation/sap temperature/etc.). In practice this means taking sap from about 2% to about 8% assuming your system can achieve the proper pressures. If you put all 3 membranes in parallel, meaning they all process sap from 2 to 8%, then you'd get 1,200 gpd from 2 to 8% (again, assuming your system -- pumps, etc.) can handle it.

To bump up the concentration, you need to put membranes in series, so it would first do something like 2% to 8%, then the concentrate from that membrane(s) would go from 8% to maybe 15+% (again, pump and plumbing dependent). If you want to achieve the highest RATE of concentrate production, you'd probably go with 3 membranes in parallel. If you want the highest concentration, you might go with 3 membranes in series, but the flow rates would be very low. For a balance of good concentration level at decent flow rates with 3 standard membranes, then a 2 X 1 (series x parallel) probably makes the most sense. Somewhat depends on your membranes and pumps/recirculation/etc. also.

[wlatrout]

Thanks Dave and Dr. Tim. '
Going to get started on it for next season. It'll be quicker then think. Good info.

[Tuckeradams2012]

Could someone explain to me what the concentrate rate would be coming out of a 2x1 parallel vs 3 series would be. I think according to research it would be 6% on the parallel version and 8% on the series? The parallel would be able to produce more concentrate just at a lower sugar content and the series would produce higher concentrate but at a slower pace?

i am trying to figure out how to be a good weekend warrior on boiling sap, so that i can remove lots of water, but be able to keep up with my evaporator when I do it. I can run it as fast as 22 gph, but around 19 is likely for me. What might be the best practical approach to accomplishing this?

Was thinking a 8852 with 3-400 gpd membranes. If my above logic holds true, would this work?

[carls47807]

Parallel or series will give you the same flow rate (gallons per hour). Series will allow the batch to flow across all three membranes, which reduces fouling and helps keep the membranes flushed. There is no benefit to a parallel configuration in these little systems.

Running a series system from 2-4% will be the same flow rate as running a parallel system from 2-4%. With a series system, you can run the water a little faster than the concentrate (but you wouldn't have to), and you could get a higher single pass concentration with less likelihood of fouling membranes (than a parallel system). Each 400gpd membrane will pass 4 gallons of water per hour at sap temp and 100psi (less than 100psi is not really satisfactory).

The aquatec 8800 is really only capable or running up to 600-800 gpd of membranes. The flow rate at 100psi is only around 16gph. The 8855 series could run three. Plan on about 24gph with 3 400gpd membranes and a sufficient pump (making 12gph of concentrate and 12gph of permeate). If you get to 150psi you might be able to do a little better (but the 8800 will probably only make 80-100psi with three membranes).

[Tuckeradams2012]

Parallel or series will give you the same flow rate (gallons per hour). Series will allow the batch to flow across all three membranes, which reduces fouling and helps keep the membranes flushed. There is no benefit to a parallel configuration in these little systems.

Running a series system from 2-4% will be the same flow rate as running a parallel system from 2-4%. With a series system, you can run the water a little faster than the concentrate (but you wouldn't have to), and you could get a higher single pass concentration with less likelihood of fouling membranes (than a parallel system). Each 400gpd membrane will pass 4 gallons of water per hour at sap temp and 100psi (less than 100psi is not really satisfactory).

The aquatec 8800 is really only capable or running up to 600-800 gpd of membranes. The flow rate at 100psi is only around 16gph. The 8855 series could run three. Plan on about 24gph with 3 400gpd membranes and a sufficient pump (making 12gph of concentrate and 12gph of permeate). If you get to 150psi you might be able to do a little better (but the 8800 will probably only make 80-100psi with three membranes).

Great info carls47807, really appreciate the feedback. If I am trying to match my 15-20 gph rig, how could I successfully build a system that would process that even if it were at a lower concentrate level? Maybe multiple pumps and 4 membranes? Because I am a weekend warrior unless we get a really big run and I go up mid-week, my RO has to do a fairly good job of keeping up. I could mix it obviously with regular sap, and maybe that's the answer, but if I at least wanted to take off half the water what would be your suggestion?

Thanks!

Tucker

[carls47807]

You could run two aquatec 8800 pumps, with 2 membranes on each (two separate systems basically). RO Bucket (me, but I am not soliciting), sells a 40gph booster pump that pairs well with 3 membranes. Also have a 60gph pump that can run up to 5 membranes. Again, each membrane will get you 8gph. Hope this helps!

[Muddy Bottoms]

Take a look at Mattatuckmadnessmaple.

He has a lot of useful info on these small systems. He is a member on here, so you can probably find it using the search engine on here. I think his user name is something like hubador.

[Sugar Bear]

Take a look at Mattatuckmadnessmaple.He

He has a lot of useful info on these small systems. He is a member on here, so you can probably find it using the search engine on here. I think his user name is something like hubador.

Mattatuckmadness also uses series and discourages the use of parallel. I think he uses 5 or 6 150GPD in series.

Another benefit to series is that you can more effectively rotate membranes between runs from first to last down the line so you even out fowling of each membrane.

[tapdrinker]

Just a heads up on this topic. I found myself fighting for a faster flow rate. I used 4x 150gpd ro membranes in series. It was super duper slow. I then cut it in half basically. 2 in series x 2... still not fast enough... .so I did the one pass on each from pump to membrane and out with 4 pin pressure needles valves. What I needed to accomplish was - evaporation rate needed to equal processing -evap-rate. I was able to boil so fast my ro couldn't keep up. I'd sometimes not use ro at all. Some trees were giving me 5-6% so i didn't process it through RO. I'm a one man operation so I needed to tilt things to one and done methodology. Just an fyi I tried to keep the flow rates equal water to perm on each membrane. I might take the extra time to process my perm one more time before boiling but again-my starcat evaps so fast... It's almost pointless with only 60 taps. The starcat with blower evaps 11.5 gal per hour. On a good day I'll only collect about 90 gal of sap. On these days I'd be running ro and evaping that as fast as possible but I nearly always had to add sap to keep my boiling going and not burning the pan. Basic thing to keep in mind-evap rate vs ro process rate. I don't let my sap sit around and/or freeze. that's another issue altogether... ro outside will freeze overnight or in an unheated garage.