Homemade RO project

[Gary in NH]

Small Sap RO Project

I’m finally getting around to posting the details of my homemade RO system. I work in water treatment and have worked with RO systems for along time. I started building this RO toward the end of the season last year from different parts from other scrapped systems. I did buy new module housings and RO membranes. This is my 1st full season using the RO system.

System details:

(2) Filmtec TW30 – 2521 RO Membranes rated @ 325 GPD each @ 225 psi
Procon Stainless Steel RO High Pressure Pump
Pressure and Concentrate adjusting valves
Concentrate and Permeate flow meters
On / Off RO Control with low pressure shut-down
Sap Pump – Procon Stainless Steel – will provide 100 psi from gravity feed
10” Sap pre-filter using 1-micron disposable cartridge

This system is located in my basement. I store sap outside in sealed containers and run a ½” line in through a basement window to feed the system. I have a 35 gallon permeate tank and a couple of 5 gallon containers in the basement to collect concentrated sap. When my 35 gallon permeate tank is almost full I redirect permeate to a dry well line. I also have hot and cold running softened water available. Washing the membranes is done by mixing up a solution of RO soap in a bucket and drawing it into the system by way of the sap pump. The system is tubed with food grade polyethylene plastic tubing. The high pressure side uses tubing that is rated for 250 psi. I have utilized push-in type quick connect fittings. This makes moving tubing around for washing or maintenance easy.

The system will process 11 gallons per hour of 34 degree F sap. Production will increase if sap is warmer. I concentrate to 8.0 - 8.5% sugar content. If I start with 65 gallons of sap I will have around 15 gallons of concentrate to boil. I can boil at around 5 to 6 gallons per hour with two propane burners and stainless steel restaurant pans. One pan gets used as a pre-heater.

The system is very small compared to most RO’s. I only have 35 taps and not all are big producers so the system works good for me. The nice thing about this system is I can start it up and walk away for several hours. I also didn’t need to invest in an evaporator. Running the propane burners off a bulk propane tank is a reasonable fuel cost. I am estimating my total syrup production will be around 5 or 6 gallons this year. My kids call the system “ The SAP-erator

[MaplePancakeMan]

That looks awesome. How much did you spend total and if you added another membrane, could you up the output?

[skinny78]

Looks good Gary! Can you explain more about washing the membranes? You mentioned moving tubing around. Have you checked your permeate sugar content? Just wondering if any sugar is getting through your membranes. I hope to build a system similar to yours next year.

[Russell Lampron]

Nice looking RO Gary.

I have seen this question asked in a few threads so here goes. I wash my RO with soap after every use. I then rinse it with all of the filtrate water that I saved from that use. I use the Lapierre RO soap and mix about 2 tablespoons with 15 gallons of water. The ph of the mixture is about 11%. This is the first season that I am checking the ph and can't seem to find what I should be setting it at. If I remember right I was told that it should be in the 10.5 to 12.5 range. My RO has a valve that by-passes the high pressure pump when I am doing a wash cycle and rinse cycle. The soap works best in the 30 to 43 degrees Celcius range and my RO machine automatically shuts at 43 degrees Celcius.

Russ

[Gary R]

Nice looking RO! Thanks for sharing the details. I would think there are lots of small producers that would love something like this instead of investing in a larger rig. Good luck with the sugarin':D

[WESTVIRGINIAMAPLER]

What do you RO guys do with really cloudy and low quality sap, won't it plug the membrane fast??

[Amber Gold]

I’m working on a 2x6 this year and plan on expanding to 50 taps next year and further expanding my operation as I find trees around town. To do that I would need to either buy a larger evaporator or buy an RO system. If it wasn’t too expensive I’d rather buy an RO. I was wondering what your full materials list is, where you get those materials, the cost, an assembly diagram and/or instructions. I’ve never seen an RO before, but am mechanically inclined.

I understand that they need to be cleaned after every use, which isn’t bad, but is there any yearly maintenance? Also how often do the membranes need to be replaced and at what cost? Also do they use a lot of electricity?

Thanks for the info.

Josh

[Russell Lampron]

Brandon, I run every drop of sap that I get through my RO, cloudy, buddy or yellowish. It doesn't seem to affect the performeance of the membrane at all. I wash mine more often than the manufacturer recommends because I don't get the sap runs that would require me to run it that long.

Josh, the amount of electricity that my RO uses is much less than the cost of the fuel that I would otherwise burn in my evaporator. I burn wood that I harvest on my own land and the actual dollars spent on fuel for the tractors, chainsaws, wood splitter, wood elevator and dump truck is still a lot more.

Russ

[802maple]

Like Russell said you can't wash them to much. If you wash them religously everyday that you use them, and rinse them before they need it, they will be like the energizer bunny. The R.O."s that we had been running 22 to 24 percent sap thru are now 7 years old and all 6 membranes are still producing over 100 percent of what they are rated to do and not passing sugar. There are sugarmakers in the area that have 12 year old membranes and they are still working well,yet when I used to service them I saw guys destroy them in 2 years as they were just to busy to take care of them, so they pay the price. My theory is when you think you have washed them enough, wash them again.

[saphead]

Jerry,I'm curious as to what brand and model # you're using.Was it Filmtec nf270 that they had the problem with?
Craig

[802maple]

I won't use the 270 as they will not allow you to go to high concentration without passing sugar as I have been finding out. All I would use is the Mark 1, they are a little slower but they will take the abuse of high concentration and come back for more.

[Gary in NH]

That looks awesome. How much did you spend total and if you added another membrane, could you up the output?

I spent around 450.00 total. The membrane housings were 95.00 each with end plugs and the membranes were 103.00 each. I could easily add another membrane to the exsiting two and increase output by 1/3. I don't think I would go to four membranes. I would need to go with a higher output RO pump. I would re-design the system and go to larger membranes. I don't have the sap to justify expanding it though. A note to those who may try this at home. I tried running this system with one membrane and recirculation of sap to the feed side of the RO pump. I couldn't get more than 4.0 to 4.5% sugar concentration. The system runs at 225 psi so I think you would need to get to the 500 psi range to get to 8.0% with one membrane. The plastic tubing and fittings aren't rated for higher pressure like that.

[Gary in NH]

Looks good Gary! Can you explain more about washing the membranes? You mentioned moving tubing around. Have you checked your permeate sugar content? Just wondering if any sugar is getting through your membranes. I hope to build a system similar to yours next year.

Permeate sugar content is non-detectable with my sap hydrometer. I am using tap water RO membranes and they let less through the membrane than a nanofilter membrane. When I clean I draw RO soap out of a 5 gallon pail and it recircs back to the pail for while. I can bypass the inlet solenoid assembly on the RO and circulate the RO soap by way of the sap pump. I can clean the membranes in series or parallel and adjust pressure and flow by the throttling valves. I usually just do it in series. I am only processing 60 to 80 gallons of sap at a time.

[Gary in NH]

Nice looking RO Gary.

I have seen this question asked in a few threads so here goes. I wash my RO with soap after every use. I then rinse it with all of the filtrate water that I saved from that use. I use the Lapierre RO soap and mix about 2 tablespoons with 15 gallons of water. The ph of the mixture is about 11%. This is the first season that I am checking the ph and can't seem to find what I should be setting it at. If I remember right I was told that it should be in the 10.5 to 12.5 range. My RO has a valve that by-passes the high pressure pump when I am doing a wash cycle and rinse cycle. The soap works best in the 30 to 43 degrees Celcius range and my RO machine automatically shuts at 43 degrees Celcius.

Russ

Russ,

Thanks for the info. Is yours a Filmtec membrane? I use the Airablo RO soap and bring the solution pH up to 11.0. I can mix with warm water since my system is in the basement of my house. Filmtec's website has info on maximum pH range and contact time for all their membranes. I could go to a pH of 13 for up to 30 minutes. I have also done a couple of citric acid washes after flushing out the RO soap. The citric acid only goes down to around a pH of 4.0. Hydrochloric acid would go lower and the membrane will take a pH of 1.0 for 30 mins. With the limited amount of sap I process I haven't had any membrane problems. My kids still talk about how nice your Mother was to them last year during Maple weekend. They really liked the sugar on snow.

[Gary in NH]

[quote=Amber Gold;44985]I’m working on a 2x6 this year and plan on expanding to 50 taps next year and further expanding my operation as I find trees around town. To do that I would need to either buy a larger evaporator or buy an RO system. If it wasn’t too expensive I’d rather buy an RO. I was wondering what your full materials list is, where you get those materials, the cost, an assembly diagram and/or instructions. I’ve never seen an RO before, but am mechanically inclined.

I understand that they need to be cleaned after every use, which isn’t bad, but is there any yearly maintenance? Also how often do the membranes need to be replaced and at what cost? Also do they use a lot of electricity?

Thanks for the info.


I started my system from a frame and components from other systems that I had available to me and I was able to buy components at cost. I don't think you could start from scratch and build one cheaper than you could find a used one somewhere. You could also look on the internet for other tap water RO systems. Try Crane Environmental http://www.cranenv.com/

[Amber Gold]

Thanks for the info.

[Russell Lampron]

Gary I have a Filmtech NF90-4040 membrane in my RO. What brand type are you using. I had a chance to check out Dows web site and see that the XLE membrane is ok to use as a replacement for the NF90 and NF270 membranes. Unfortunately they don't make a 4" Mark 1 membrane. I also found that 12 is the ph number that they recommend for a caustic cleaner.

[Gary in NH]

Gary I have a Filmtech NF90-4040 membrane in my RO. What brand type are you using. I had a chance to check out Dows web site and see that the XLE membrane is ok to use as a replacement for the NF90 and NF270 membranes. Unfortunately they don't make a 4" Mark 1 membrane. I also found that 12 is the ph number that they recommend for a caustic cleaner.

I am using Filmtec TW30-2521's. They are tap water membranes. The operational spec per Filmtec for this membrane is pH 2-11. Short term cleaning up to 1/2 hour is pH 1-13. If you ever want to try an XLE 4" x 40" let me know. I have several on hand. The XLE designation means a low energy (low pressure) membrane. They typically run at 120 to 150 psi.

[Russell Lampron]

Gary,

I would very much like to try one. I have been reading the specs for the XLE and it will produce 1000 gallons more permeate per day than my NF90 which does 1500 gallons per day. The spec sheet also says that the XLE can be operated up to 600 psi but doesn't say what the optimum pressure should be. It looks like less sugar will pass through it too. Send me a pm and we can discuss the details of this further.

[mapleman3]

802.... 22% sap??? isnt that kinda harsh, I thought I heard from many out there that you shouldnt go more than 12% for taste... less boiling less flavoring by the natural carmalization by the heat??? I'm just learning so I'm just asking.

[802maple]

I have said on here before that 22 percent sap does have a lighter flavor then 12 percent but not a bad flavor. When the packers buy it they like it as they blend most of there syrup into Dark amber anyway. They can get away with using the crappy late season syrup when they can blend with the lighter flavored high concentrate. Also I think that some off flavors that come from so called high concentrate comes from sugarmakers concentrating to far ahead and letting it set until they feel they have enough to boil. When I high concentrate I feed the sap almost directly to the evaporator, and at 22% or more I can make 130 gallons of syrup per hour, and burning 22 gallons a hour of oil, it is a no brainer. 6 gallons of syrup to a gallon oil

[wagnerppw]

Gary,
Would you have any interest in building one for me? If so how much would it cost? I could pick it up. Let me know at wagnerppw@oecblue.com.
Barry

[crrogers]

Gary, Could you put together a plan with a drawing and list of materials. Willing to pay for plan.

Cliff

[Brent]

Gary I have a Filmtech NF90-4040 membrane in my RO. What brand type are you using. I had a chance to check out Dows web site and see that the XLE membrane is ok to use as a replacement for the NF90 and NF270 membranes. Unfortunately they don't make a 4" Mark 1 membrane. I also found that 12 is the ph number that they recommend for a caustic cleaner.

Be careful with that pH of 12 ... it is temperature dependant. From memory the Dow site says pH 11 at 115 F and pH 12 at a lower temperature ... like 105F. Better double check that before you ruin the membranes.

That's a great rig for a small producer. You did your homework well. I would add another permeate tank for flushing though.

One other thing. When you start an acid wash, start with a pH of 1 to 2, run the system for a while and you'll see that the pH drifts back towards neutral 7. Add more dry acid to the brew to bring it back to 1 to 2. The acid is being neutralized as it "eats" the minerals off your membranes. When the acid does not drift back to neutral, there's no mineral left on the membranes and you're done.

[MFarmall]

Gary,
I am in the process of building my own RO unit and will be using an XLE-4040 membrane. I have read the specs for ph when cleaning, so if I run around 10-11 ph for short wash (1/2-3/4 hour) I should be ok? The pump will be around 150-160 psi. I am building it so I can add a 2nd membrane after next year if need to and up the pump capacity fairly easy.
Mel

[doolittle syrup]

Hello Gary and other members;
New to your interesting site. Would like advice or help to build RO unit myself. I have excess to stainless items and capable to weld. Using small brothers 3'x10' evaporator with 2 3'x2' finish pans. Also steam pre heat over evaporator pan. Wood fired arch with forced air fire box. We are tapping 1200 taps,200 on pipe line and 1000 on pails. Currantly can boil down
125 - 150 gal sap per hr. Best sugar count 3% , but normally 2% and down to 1.5 % by end of season. Means lots of
time and lots of wood. Any help with ideas or plans for RO unit much appreciated ! Doolittle Syrup, Big Falls Wi.

[JRCunningham]

5375First post--so I should start by expressing my gratitude for you all and sharing your hard earned knowledge with the rest of us. I sincerely hope I can share my successes and mistakes with you all as I become more deeply committed to my family, my land, and my maple trees.

I just deployed a (very small) RO this year (Gary, you will recognize the name on the control box), and I must say that I'm extremely satisfied with it thus far. As most of you more knowledgeable folks on this forum have identified, I have found that running my concentrate flow at a high rate (in the case of my unit, minimum specification is .52GPM and I run at 1.2GPM), and running permeate flow at a slightly high rate (for my unit, specification is .17 GPM, I run at .25GPM).

I have a connection (my father-in-law) which makes my RO more of a BTU-vs-KWH calculation, and I'll take the KWH cost any day. This stated, capital costs will have to be considered for future expansion--at the moment I'm just grateful to take any water out I can before I strike a match...

Anyway, back to the thread at hand. I have run my concentrate as high as 15% before boiling, and I have been asked by some folks at Culligan to run it higher at the end of the season before I have membranes cleaned, just to see where things start to go south. Thus far, my observation is that concentrate flow is key--the concentrate washes the membrane, and if I can keep the concentrate flow significantly higher than specification, whilst keeping the permeate flow slightly higher than specification, I maintain an adequate wash flow across the membrane which prevents clogging of the membrane. I have a TDS meter, and have thus far kept my dissolved solids at 4 PPM on the permeate side, with no deviation at all. My permeate flow has remained stable as well.

Now, the season is young, and I'm a newbie--so please take my observations with a grain of sal..err..sugar. It would be my privilege to continue to report to the group as the season goes on.

I thank you for your knowledge, and I will endeavor to repay you with mine as the years go on.

--J.R. Cunningham

[americanwingfarm]

If I were to put a pump that does 3gpm in a unit like this would it cause harm to the reverse osmosis or would it just mean my sap is less concentrated. I am planning on building one for next season, but I didn't need it to concentrate as high as you ate concentrating, I was thinking 4-8% no more than that. If this is a possibility would it be possible for you to send me a parts list?
Thanks, Tim

[Greenthumb]

9791I made this small ro and worked great for our 40 taps. Going to about 80 taps next year.
My one question is were to keep it. In my shack things freeze especially in the first few weeks. Would it be ok as long as all is drained to have it freeze. I took it into the mud room on nights I new we where going to get real cold. When in use I used it in our garage which left my wife's car outside. I would like to get all processes in our sugar shack ro, boil and bottle
9789

[hodorskib]

Your setup looks like the one I built. You never want the membranes to freeze even if they are drained since they will still have moisture in them. Looking at your picture you can easily pop off the feed line and the lines going to concentrate and permeate and just bring them in. I have heard of some people who built a box out of insulation board and put a regular light bulb inside which will generate enough heat to keep everything from freezing but have never tried

[jrgagne99]

Build a blue-board box with the 60W lightbulb on a thermo-switch from home depot. That way the light comes on if T<40F and switches off once T>50F. Check out my thread for pictures.

http://mapletrader.com/community/showthread.php?12517-Homemade-RO/page4

[maple flats]

I heat my RO room, which is insulated with 3" foam Hi R panels, and I use light bulbs on a low range thermostat. While 1 100w was good to about 10 degrees and 2 good to -25, I used 4, in case 1 blows. My bulbs are on a dedicated circuit on my solar battery back up system, thus if the grid power fails, that 1 circuit still works. With grid power on, it runs off the grid if the batteries are charging and solar if they are fully charged.

[maple flats]

For a basic homemade R.O., Steve Childs, Cornell Maple Specialist, has some you tube video's, he shows 3 sizes I think, maybe more.. Here's some links:
https://www.youtube.com/watch?v=m_fu2bPPwqQ
https://www.youtube.com/watch?v=8YFmc2a50To
https://www.youtube.com/watch?v=_BOO2L1RD2s
and here's 2 more, defining an RO and cleaning:
https://www.youtube.com/watch?v=b6Fgf1cfzEs
https://www.youtube.com/watch?v=gEQEumoRrqI

[Fleman202]

I am planning on building an RO this winter. I don't think I need it to process any more than 50 gallons per hour. If anyone has built one like this I would be grateful for any plans or info you could provide. I would pay for a set of plans and materials list!

[huntermck]

Hey i am building a Home made R.O system for my operation, and was wondering if anyone out there knows where i can find a lead-free water regulator that will output from 200-250 PSI. I am using 2 stainless steel housings/membranes sized 2.5 x 40. I have only been able to find regulators up to 160 psi, which i fear will not be enough pressure. yes it would concentrate better, but it would plug the membranes quicker. thanks

[Super Sapper]

You do not need a regulator, that would only decrease your pump efficiency. Your pressure is regulated with your concentrate valve on the discharge side of the membranes. The more you close it the higher the pressure.

[wiam]

You do not need a regulator, that would only decrease your pump efficiency. Your pressure is regulated with your concentrate valve on the discharge side of the membranes. The more you close it the higher the pressure.

If you do not have a regulator and something plugs you can blow apart pipe, fittings or membrane housings.

[Clinkis]

If you do not have a regulator and something plugs you can blow apart pipe, fittings or membrane housings.

This is why you have a high pressure shutdown switch. Which i will tell you from experience (bad ones) is absolutely necessary. I usually operate my RO between 200-250psi and I recirculate. My first year with my RO I blew the end caps off my membrane housing twice when pressure creeped up and I was busy and didn't notice. Last year I install a high pressure shutoff which will kicks off the RO if pressure gets over 275 psi and it was a life saver.

Some pumps like the procons have optional pressure relief built in but they usually will limit the pressures you can operate at.

[wiam]

This is why you have a high pressure shutdown switch. Which i will tell you from experience (bad ones) is absolutely necessary. I usually operate my RO between 200-250psi and I recirculate. My first year with my RO I blew the end caps off my membrane housing twice when pressure creeped up and I was busy and didn't notice. Last year I install a high pressure shutoff which will kicks off the RO if pressure gets over 275 psi and it was a life saver.

Some pumps like the procons have optional pressure relief built in but they usually will limit the pressures you can operate at.

That is why I have a pressure regulator and a high pressure switch. Cause I don't trust electronics when I'm not there.

[Super Sapper]

A pressure relief valve would be the proper thing to use. With the regulator you will still build the pressure in the pump and everything leading up to the regulator.

[SmellsLikeSyrupNH]

Can anyone give me an example of what type of pressure switch you use?

I have a NEXTGen Maple RO that I just purchased and do not have the model with the pressure switch or the model with the automatic shutoff, so Id like to perhaps install both myself, the RO itself doesn't seem very complicated simple 110v power switch to a pump then the normal RO components, i.e. a prefilter and a RO membrane with the Pressure gauge and valve on top of the membrane housing.

Thanks!

[wiam]

A pressure relief valve would be the proper thing to use. With the regulator you will still build the pressure in the pump and everything leading up to the regulator.

They are the same thing. Adjustable spring loaded valve that lets over pressure return to the low pressure side of the pump.

[Super Sapper]

Pumps with them internally will function that way but there are different types of regulators out there that do not do this. It is important in this application that the right style is used to avoid blowing up a pump. The style that just necks down the line to achieve a certain pressure downstream will not work here. They style you are talking about will open and discharge out another port and can be directed back to balance tank.

[Clinkis]

This is what I used for my high pressure switch. It's a simple mechanical switch that does not require any fancy electronics to incorporate

http://www.dwyer-inst.com/Product/Pressure/SinglePressure/Switches/SeriesA1PS-A1VS#ordering

A pressure regulator and a pressure releif valve are not the same thing. A pressure regulator is designed to maintain pressure within a system at a certain level (like a propane regulator). A pressure releif valve is designed to protect a system if pressure gets too high when all else fails (like what's on a hot water tank).

.