New RO Build

[HowsItRunning]

I've finally completed my first RO build, and I certainly couldn't have done it without all of the help available on this forum and on youTube, so thank you! Special thanks goes to Roseum Maple for their detailed information and discount on the membranes. I'm putting up a few pictures in case this design can help someone else who's considering a build. If nothing else, maybe I set a record for the number of control valves, lol.

I'm only processing 16 taps, so my hope is to remove as much water as possible since I'm burning with propane. I'll be using a high re-circulation rate, maybe 5:1, in order to do this, so hopefully I can achieve this quickly before bacteria growth gets out of hand.

Probably like many newbies, I'm worried about fouling the membranes since they are so expensive. My plan is to set the initial pressure so the last membrane has a recovery rate no higher than 20%, and no higher than 100 psi. As permeate flow slows, I'll try increasing pressure up 100psi, if there's room to increase it. I'll also monitor the TDS of the permeate to see how effective the filtration is, and if it starts to climb, I'll shut down, then rinse and clean. Does this seem OK?

On a side note, I plan to boil the concentrate straight to sugar, not syrup. Besides filtering the sap, I'll probably filter again around 214F before it gets too difficult to filter. I'm assuming I don't need to worry about niter since I'm making sugar, is that correct?

Thanks again, and good luck to all this season...

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[NaVGF]

Looks great, it’ll make your boils a lot quicker. If I can offer any advice, Throw a hand hold on it and set yourself up with a RO suitcase.

[DRoseum]

Looks great! Glad the info and discount codes helped.

Your plan is good. Did you build in a recirc loop? It looks like you did. That helps keep psi amd recovery rate low like you want while also outputting a higher sugar concentration.

You plan to go right to sugar for all the sap you collect?

Even with that approach, you may still want to filter. The niter will still be in the final sugar product and may give it some off flavor / texture depending how much there is. I am really not sure though as I have only made sugar from syrup I had previously finished and filtered.

[fireant911]

Very nice looking and clean setup!!! I 'think' that I am asking the same question as DRoseum did... in the first photo, what is the purpose of the branch just before the pump? - is that a recirculation loop? Regarding the three flow valves on the lower right side of the same picture - what is the purpose of those? And one final question: what do the five shutoff valves do? Excuse my lack of knowledge as I just have one year of RO experience and I am curious about this arrangement. I sure am glad that pictures can be posted again as it is nice to see other's designs and creativity!

[HowsItRunning]

Wow, this site is getting interesting...I wrote a reply to this topic and within that time my login timed-out and I lost the entire post, it was maybe 15 minutes. So here goes again...

The two valves on the left are shut offs to the output of the filters, those combined with the one on the upper right [the input to the filters] are used at the end of season to trap the wash/preservative around the membranes for the off season.

The lateral run on the bottom is the concentrate output from the filters on the back, it goes to the needle valve to set the high-pressure, it then goes to a drain T to empty the tubing at the end of the year. That then T's up to the recirc loop. After that T is a valve to set the recirc level, and the concentrate then outputs through the gauge on the right. The second lateral run from the bottom is the permeate which runs to the bottom of the middle gauge and out the top to a bucket. The third lateral line from the bottom is the recirc loop which comes out of the top of the left gauge, through a check valve and back to the input.

The gauges are a nice-to-have and because I'm a geek, lol. I'm also very concerned about over stressing the filters and damaging them, so this should make it easier control.

For the sugar, is it fair to say niter has no maple flavor [and maybe an off taste]? I think it would be best to let the near-syrup settle overnight and pour off the clean syrup, repeating for every boil until the end of season when I'll toss the niter and syrup that has settled to the bottom.

Thanks...

[fireant911]

Nice explanation! I think I will 'copy-cat' your shutoff valve idea for trapping the wash/preservative around the membranes between seasons. One more question regarding the two pressure gauges at the top of your setup: it looks like each gauge has two needles? Is the upper one indicating system pressure and the lower one for temperature? If so, where did you get these gauges?

[TheNamelessPoet]

What are the 3 "gauges?" on the right hand side?

[HowsItRunning]

Yes, the gauges show temperature and pressure, I got them on amazon.

The three gauges on the right measure the flow rate of the recirc, permeate, and concentrate.

[Shameful1]

I have been lurking for a while and posted a couple of weeks ago as I was building the RO because one of the 300 GPD membranes was deliverd damaged and they only had 400GPD for replacement. This community was very quick to respond to my question and the 400 will be placed first in the series of membranes. So here it is, looking for feedback and possibly what I can expect for output. I am still trying to wrap my head around Recovery and recirculation. My RO is a combination of many I have viewed here and youtube. So if you see something familiar that is why, and many thanks to DRoseum from this site and Samuel Wiltzius of Offgridcabin for your ideas. So 1 400 GPD membrane followed with 2 300GPD membranes with a recirc loop with a separete needle valve to control the recirc flow. Using a Aquatec 5357-2LM2-B738 Booster Pump that according to performance data will flow 1.4 GPM @ 90psi. Here are a few pics.

Thanks, Steve

[DRoseum]

Steve - this looks great!

Let me know if you have questions ...glad to try to help.

Generally at 40F your 400 gpd membrane will process ~4gph of permeate. The 300s will each take out another ~3gph. So ~10gph of permeate total.

Recirc works great for upping your concentration while keeping higher flowrates across the membranes (keeping recovery rates and fouling lower). Your final concentration output will asymptotically increase and level off. The higher you take % conc, the harder it is to take water out.

After some "practice" you will find the sweet spot for your operation

[Shameful1]

DRoseum, thanks for the reply and input, as you can see I left room for another membrane if needed. Our boil rate is around 10 GPH so was hoping to at least match that. We have 100 taps on 3/16" running into a 1" main, so on good days we can see 150 gallons and would like to RO and boil at the same time. We have room to add another 50 or 100 taps so this is a trial and error mission. It will take some practice, but I am excited to see what can be done.

Steve

[Shameful1]

So did the initial flush of the RO today getting ready for sap hopefully tomorrow. The most I could get for pressure was 20 psi with the bypass open, so after 30 minutes of flushing (that's what membrane solutions recommended) I closed the bypass and I tried dialing the concentrate needle valve in to increase pressure but had no increase. I could shut off the flow completely but no increase in pressure. Is my assumption correct that the water is clean enough that it is free flowing and when I add sap to the system the pressure will increase? OR?? I really thought I would see at least some pressure increase. Additionally, when I shut the flow off with the concentrate needle valve the permeate line had no increase in flow which I thought was odd. Thoughts??

Thanks, Steve

[DRoseum]

Water will operate at lower pressure, especially if room temperature. Also, you have a recirc loop, right? If that is open you won't see pressure increase.

When starting with sap, or when flushing afterwards, always have your recirc loop closed. Once you have air out and pressure dialed in with sap, open it up and then adjust again to your liking.

For flushes keep it 100% closed the entire time.

[Shameful1]

I did not open the recirc, just opened the bypass valve, then closed the bypass valve after flushing the membranes and tried to get pressure to build with the concentrate needle valve and it stayed the same 20 psi. Checked with my TDS meter and water temp was 48.6 and PPM was 72 so pretty clean. Sap starting to run (we are in the Northwest Mountains of Maine) and have maybe 100 gallons in the tank on the hill. We need 150 gallons or more to even start, between evaporator, head tank, concentrate tank and raw sap to RO. Really hoping the sap is the key, 20 psi won't do much as far as bringing the brix% up, need to get to 85 or 90 psi at least. Side note, the pump is super quiet so no issues having it in the sugar house, we will still hear the music...

Thanks again, Steve

[Shameful1]

Water will operate at lower pressure, especially if room temperature. Also, you have a recirc loop, right? If that is open you won't see pressure increase.

When starting with sap, or when flushing afterwards, always have your recirc loop closed. Once you have air out and pressure dialed in with sap, open it up and then adjust again to your liking.

For flushes keep it 100% closed the entire time.

You were spot on, I didn't have the recirc open but there was an air leak before the needle valve. Fixed that and ran sap yesterday worked great. Straight run with no recirc at 110 psi we went from 1.4 brix to 3 and about 10 gallons an hour. Added the recirc and and was able to get it to 6 brix but the flow was not great at 115 psi so dropped it back to 110 and we got 5 brix and about 7 gallons an hour concentrate. I am adding a 4th 400 GPD membrane hoping to run 95 or 100 psi and increase the flow and keep the brix up. Also when flushing I just opend the bypass valve and 20 minutes and things were cleaned up pretty good at 4 PPM coming out the concentrate line. Is that the best way, no pressure and through the bypass?

Thanks for your help, Steve

[DRoseum]

Awesome.

I normally use a couple gallons of permeate to flush sugar off membranes at the end thru the bypass with the sap filter in and recirc and normal output closed. I catch that in bucket until system is pushing only air out, check the sugar % and toss into head tank to boil if it's above 1%.

Then replace the sap filter with my "rinse" filter, clean out the pump strainer, and run the rest of the permeate thru to fully flush it all out.