Must a cheap RO be $5000+?

[NTBugtraq]

I only have 130 taps, so spending $5k+ makes no sense to me, but are there cheaper alternatives? I had RO in my house many years ago, it didn't cost $5k...??

Cheers,
Russ

[KevinS]

there are many people using homemade RO's that have a lot less than 5 g in them. but you still need to use good sized membranes and several of them to do enough, fast enough to make it worthwhile.
several people have posted their plans and designs on this forum. just search "homemade RO"

[KevinS]

http://mapletrader.com/community/showthread.php?12517-Homemade-RO&highlight=home+made+RO

[bowhunter]

I've built a small RO which is capable of 16 -17 GPH. It takes 2.5% sap to 7% once through yielding about 6 GPH of concentrate. It cost about $900 to build. I think you can double that capacity for about $1,200. I'd be happy to give you a list of the major pieces of equipment as an idea. Just give me a little information. How fast you want to process sap? Sap sugar level and how high you want to concentrate it on each pass. I would recommend matching the RO to the capacity of your evaporator so you don't have to store concentrate.

[mantispid]

I built a 100GPD (about 4.5GPH of sap) RO system for less than $500, but a simpler one could be built for less than $300. I used the plans found on this site:

Homemade Reverse Osmosis System (https://sites.google.com/site/mattatuckmadnessmaplesyrup/home/homemade-reverse-osmosis-system)

I use 150GPD membranes that run about $45 each, and it concentrates my red maple sap from 2% up to about 7.5%.

I usually let it run overnight and then boil the concentrate on the evaporator the next day. During the colder parts of the season, I'll let it run a couple days before boiling. Concentrate spoils pretty quickly once the temperature gets much above 45F, but below that it seems to keep rather well. A few days at least.

[maple flats]

My Ray Gingerich RO is a 250 GPH and they cost about $3500. Ray also makes a 125 GPH for about 5-600 less. I've heard he also makes one even smaller but I don't know the price. PM me and I'll send you his phone number. Also, Waterguy RO's are in that price range but are more. Unless you plan to get much bigger, an RO from one of the small producers in the 50-75 GPH range will be plenty big enough and will cost far less than those prices and it will be a tested design rather than trial and ERROR building your own. While many make their own RO's, I vote no on that, however I have made several other maple items.
In fact, for about $5000 you can get a 1000 GPH unit from Ray (in 2012 it was $4700 with high and low pressure shut offs).

[heus]

I swear by Ray's RO! It has totally changed my operation for the better.

[Bucket Head]

I bought a used machine that needed a lot of work. I took it apart and replaced all the hoses, seals, gaskets, high pressure line, a pressure gauge, etc., and came a way with a decent machine for a lot less than a new one. Maybe not the route you want to go, but its food for thought.

Steve

[HowardR]

I've built a small RO which is capable of 16 -17 GPH. It takes 2.5% sap to 7% once through yielding about 6 GPH of concentrate. It cost about $900 to build. I think you can double that capacity for about $1,200. I'd be happy to give you a list of the major pieces of equipment as an idea. Just give me a little information. How fast you want to process sap? Sap sugar level and how high you want to concentrate it on each pass. I would recommend matching the RO to the capacity of your evaporator so you don't have to store concentrate.

Bowhunter,

Please do post your part list and if possible a little diagram, a photo, or a description! Your system is exactly the size and cost that I want for the one that I'm planning to build this year. I was hoping to hear whether it worked when you briefly outlined your plan to use a 140 GPH Procon pump and 580 GPD Axeon NFR in a thread last spring.

[stoweski]

Spoke to Ray back in Jan at Verona. He mentioned working on a small RO around 50 GPH. Didn't say much about price but hinted at sub-$1k. May be worth a look for someone with 150 taps.

[bowhunter]

Howard,

I bought most of the major components from https://www.freshwatersystems.com/. There may be better options, but they seemed pretty reasonable.

Membrane Axeon NF- 4 2540 680 GPD Nanofiltration membrane (equivalent to Dow NF 90)
Axeon PVC membrane housing - 2.5 x 40 inch
Procon 140 GPH Pump
Procon Carbonator Motor - 1/2 HP 120 V
Procon V-band clamp - clamps motor to the pump
Pentak 10 " slim line water filter housing
10" 5 micron filters
0-300 psi filled pressure gauge
Blue White - F-440 Rotameter 0.025 GPM to .25 GPM for the Concentrate
Blue White - F-440 Rotameter 0.1 GPM to 1.0 GPM for the Permeate
3/8 " OD LLDPE Tubing
3/8" John Guest Fittings
2- 3/8 " brass needle valves ( bought these at local building supply store)
miscellaneous 3/8" copper fittings and tubing for needle valve manifold.

I don't have a sketch, but the flow is pretty simple. The sap flows out of the head tank and through the 5 micron filter. From the filter it flows into the pump. Out of the pump into the membrane housing (side connection). The concentrate flows out the side fitting on the other end of the membrane housing. I have the pressure gauge located on the concentrate tube out of the membrane housing. From the membrane housing the concentrate goes to a "tee" and splits with one stream going through a 3/8 " needle valve to the pump inlet and the other goes through a 3/8 " needle valve and through the concentrate rotameter. The permeate comes out one of the center ports on the membrane housing and through the permeate rotameter. I'll try to find pictures, but can't find them right now.

To operate the system make sure the pump is liquid full and both needle valves are open. Use the concentrate needle valve to control the flow of concentrate and the recycle needle valve to bring up the pressure. Try to keep the concentrate flow higher than target during the startup. Bring the pressure up slowly over the first 30 minutes and allow the system to line out before you make the final adjustment on pressure and concentrate flow. When you start up the permeate flow will be higher at the same pressure because the membrane is full of permeate from the previous permeate wash. Watch the sugar on the concentrate and try to keep it below 8 %. If you go too high too quickly the membrane will start to foul. The performance will naturally drop as you continue to process through the day so you will gradually have to increase the pressure to keep the split of concentrate and permeate.

The tubing and John Guest fittings worked really well. I ran up to 250 PSI with absolutely no problems

I tried to model the system in a spreadsheet using all the publicly available I could find. The one thing I couldn't model very well was how the sap fouled the membrane. It worked really well on water at different pressures and temperatures. In any case my system will consistently process 16-17 GPH of sap and take it from 2.5% to 7%. It des better right after a caustic wash and not quit as well when it's time to wash again. I feed the concentrate directly to the evaporator and I really like that approach. I did sometimes recirculate back to the sap tank, but I really don't like to store concentrate.

I have the good fortune to have my sugar house in a small two story barn so I have a 55 gallon drum on the second floor to feed the system. This worked well, but be prepared to change the filters after each day of processing. I didn't have any debris on the filter, but they still plug with fine material and slime from the sap.

Make sure you can flush at 2 GPM or so with permeate. My permeate tank was at floor level up on blocks and I didn't always have enough head pressure to overcome the filter fouling at the end of a run unless I changed the filter first.

Hope this helps. I can answer question on a private message or e-mail if you want.

[HowardR]

Thank you Bowhunter! Your parts list and description should enable me to put it all together. How did you end up mounting it so you could bring it in at night? A picture would be very helpful!

[HowardR]

Bowhunter,

The only thing I found confusing was exactly how you plumbed the recirculation connection between the 5 micron filter and the pump. I'm guessing that there was a checkvalve that you didn't mention there, otherwise the recirculating semi-concentrate from the 3/8 inch needle valve could have flowed backwards through the 5 micron filter toward the tank. In other words, I'm guessing the following:

Five Micron filter -> checkvalve ->Tee

with the other connections of that Tee: (1) going into your pump and (2) coming from the 3/8" needle valve that controlled your recirculation.

Could you describe your connection between the 5 micron filter and the pump a bit more fully?

[markct]

Why would it flow backwards if the pump was sucking it in? A checkvalve would only do anything when shutdown

[HowardR]

Mark, of course! Thank you.

[bowhunter]

I have a room in my barn that I can heat so I mounted it on the wall using I think it's called uni channel. It's a "U" shaped channel that's used to mount conduit in commercial or industrial construction. Some people mount the system on a hand dolly so they can move it around. I'm not a fabrication guy so I can't offer too many good options for mounting. I couldn't find pictures...I had some, but don't know where they went. I'll try to remember to send you a picture over the week-end. Also you can send me a private message with questions if you want.

Everyone asks about check valves and you can use them but for the most part they aren't necessary. You might want to use check valves where you tie in caustic wash or permeate wash so you don't get sugar back in those systems or vice versa. I disconnect the membrane from the system when I do a caustic wash so I don't have any back contamination.

[HowardR]

Bowhunter,

Thank you for the info about how you mounted it. Did you have to bring your nano membrane inside overnight so it wouldn't get damaged by frost?

I think I've found all of your parts on the freshwatersystems.com website. Could you let me know if I have made any mistakes:

1. Membrane Axeeon NF - 4 2540 g80 GPD Nanofiltration membrane (equivalent to Dow NF 90). Cost $204.74:

http://www.freshwatersystems.com/p-6862-axeon-nf3-2540-850-gpd-nanofiltration-membrane-element.aspx

2. Axeon PVC membrane housing 2.5 x 40 inch. Cost $98.98:

http://www.freshwatersystems.com/p-6902-axeon-200520-25-x-40-pvc-membrane-housing.aspx

3. Procon 140 GPH Pump. Cost $107.54:

http://www.freshwatersystems.com/p-8256-procon-pump-nsf-brass-w-188-double-flat-drive-140-gph-38-npt-130-psi-relief-valve.aspx

4. Procon Carbonator Motor - 1/2 HP 120V. Cost $155.33:

http://www.freshwatersystems.com/p-5146-procon-rocarbonator-motor-12-hp-100-120v230-vac-single-phase.aspx

5. Procon V-Band Clamp. Cost $6.50:

http://www.freshwatersystems.com/p-5309-procon-v-band-clamp.aspx

6. Pentac 10" slim line water filter housing. Cost $15.19:

http://www.freshwatersystems.com/p-658-pentek-158008-10-slim-line-water-filter-housing-38-clear-sump-no-pr.aspx

7. 10" 5 micron filters. Cost 2.97 if you buy one, or 1.83 each if you buy 50:

http://www.freshwatersystems.com/p-102-neo-pure-mb-25098-05-9-78-polypropylene-sediment-depth-filter-5-mic.aspx

8. 0-300 psi filled pressure gauge. Cost $22.14:

http://www.freshwatersystems.com/p-4567-noshok-bottom-mount-25-water-pressure-gauge-0-300-psi-ss-14-npt.aspx

9. Blue White - F-440 Rotameter 0.025 GPM to .25 GPM for the Concentrate. Cost $67.82:

http://www.freshwatersystems.com/p-3607-blue-white-f-440-rotameter.aspx

10. Blue White - F-440 Rotameter 0.1 GPM to 1.0 GPM for the Permeate. Cost 90.82:

http://www.freshwatersystems.com/p-3607-blue-white-f-440-rotameter.aspx

11. 3/8 " OD LLDPE Tubing. Cost 29 cents per foot:

http://www.freshwatersystems.com/p-887-38-od-lldpe-polyethylene-tubing.aspx

12. 3/8" John Guest Fittings:

http://www.freshwatersystems.com/c-764-john-guest-superseal-fittings.aspx

[bowhunter]

It looks like you've got everything. As with all plumbing jobs you will have to make several trips to the hardware store when you start putting it together. I kept the RO in a room with a milk house heater so I kept it above freezing, but to be clear you shouldn't leave it out where it will freeze. One more thing to keep in mind. RO's are very sensitive to sugar concentration so if you start out with 2% sap this unit will probably treat 22-24 GPH, but if it's 2.5% or higher the capacity will be down around 16 GPH. At the end of the day your target should probably be 6.5 -8% concentrate. If you try to go much higher with one of these homemade units you will dramatically reduce the capacity and the ProCon pumps are limited to 250 PSI.

Looks like you're from up in God's country....I lived just north of Pittsburgh for five years. Good luck. And let me know if you have more questions. I won't be checking the forum as often now, but if you leave me a private message I will get an e-mail.

[HowardR]

Bowhunter,

Thank you for the offer to answer questions by email that may come up when I put it together.

I think your design is brilliant. I like all these things about it:

1. Low cost -- professional parts at only twice the cost of a system that uses residential parts.

2. Simplicity -- you get from 2% to about 7% with one membrane, one motor, and one pass.

3. Engineering -- you don't give the motor too large a load or the membrane too low a flow.

4. Nano -- They do better when the sap is cold.

5. Ingenuity -- A brilliant and controlled way of recirculating the flow to get the right concentration, using just two valves.

[HowardR]

By the way, here's a little hand drawn schematic of Bowhunter's RO:

9637

[HowardR]

Bowhunter (or anybody else who has used PVC Membrane Housing),

How did you connect your membrane housing to your 3/8" tubing?

[HowardR]

If anybody else is trying to use my part list for building your Bowhunter's design RO, I've already found two mistakes in the links I published:

1. I gave the wrong link to the membrane housing. The correct links to two alternative housings (PVC and stainless steel) can be found as "accessories" on the right side of the membrane's webpage, which is:

http://www.freshwatersystems.com/p-6862-axeon-nf3-2540-850-gpd-nanofiltration-membrane-element.aspx

You'll see that the cost of the correct PVC housing is $113.40, not $98.98. (I may decide to go with the stainless steel.)

2. I also gave the wrong link to John Guest fittings. I linked to John Guest SuperSeal fittings. The correct link is to John Guest PP Series Polypropylene Fittings:

http://www.freshwatersystems.com/c-500-john-guest-pp-series-polypropylene-fittings.aspx

Most of the threads on these John Guest fittings are nptf, which look just like npt threads (sometimes called mpt threads) but they don't act the same. The nptf threads are better for high pressure systems and they seal without requiring teflon tape. In contrast, npt threads require teflon tape. The filter, for example, has nptf threads but the pump has npt thread. I will probably get the following npt fitting from the DM Fit Polypropylene fittings section of the freshwatersystems.com website:

http://www.freshwatersystems.com/p-8366-dmfit-straight-mnpt-male-38-push-in-x-38-mnpt.aspx

As Bowhunter pointed out, you won't be able to get all of your fittings from freshwaterfittings.com. So, I'll be checking out my local hardware store for the rest.

[HowardR]

I'm thinking of possibly including a low pressure electricity shutoff switch in my homemade RO to protect the procon pump if my sap feed line starts feeding in air instead of sap. Has anybody tried that in their homemade RO?

Freshwatersystems.com sells an Aquatech low pressure shut off switch for just $22.30 which I think would work:

http://www.freshwatersystems.com/p-4438-low-pressure-shut-off-switch-18-male-npt.aspx

[HowardR]

I just completed building this RO. I haven't tried it out, because I don't want to get the membrane wet until next spring. Here's how I did it. If anybody else builds an RO using the same essential design, I hope they post pictures here on this thread. The functional design is shown in the diagram below:

9735

Not shown in the diagram is that there are two additional inputs at the filter which are used in the wash cycle. The first is before the filter and comes from the soap (i.e., lye) wash bucket and there is an input just after the filter from the rinse (i.e., permeate water) tank.

The completed RO is shown in the photo below:

9736

The components from left to right along the bottom are the (1) prefilter, (2) membrane housing, and (3) motor with pump attached to bottom.

The components from left to right along the top are: (1) needle valve for the recirculation line, (2) pressure gauge, (3) needle valve for the concentrate output, (4) rotameter for the permeate output, and (5) rotameter for the concentrate output.

Here is the part list. The total cost (not including the dolly which I already had) was $1,031.

Got local welder to make
1 -- ¼ inch thick steel sheet 13.5” x 32”, $40
1 – ¼ inch thick steel sheet 3” wide x 7” long, bent at a right angle so that side is 3” wide x 2” and top is 3” wide by 5”, $5

From hardware stores
7 - 3/8” bolts 2 inches long fine thread, $5.20
4 – 3/8” bolts 1 inches long fine thread, $1.60
11 – 3/8” lock nuts fine thread, $4.40
9 – 3/8” washers $1.08
1 small box SP Sheeters 10x1”, $3.35
1 – medium duty orange electric extension cord, $6.99
2 – cans of Teflon pipe seal tape, $2

From auto supply store
2 - 2.5” muffler clamps, $3.18

From Freshwater Systems.com

1 - Axeon NF3-2540 850 GPD Nanofiltration Membrane Element (the membrane), $204.74
http://www.freshwatersystems.com/p-6862-axeon-nf3-2540-850-gpd-nanofiltration-membrane-element.aspx

1 – Stainless Steel Membrane Housing 2.5’ x 40” 3/8” Feed (the membrane housing), $134.99
http://www.freshwatersystems.com/p-7049-stainless-steel-membrane-housing-25-x-40-38-feed.aspx

1 - Procon Pump NSF Brass w/ .188" Double Flat Drive 140 GPH 3/8" NPT - 130 PSI Relief Valve (the pump), $107.54
http://www.freshwatersystems.com/p-8256-procon-pump-nsf-brass-w-188-double-flat-drive-140-gph-38-npt-130-psi-relief-valve.aspx

1 - Procon RO/Carbonator Motor 1/2 HP 100-120V/230 VAC Single Phase (the electric motor)- $155.33
http://www.freshwatersystems.com/p-5146-procon-rocarbonator-motor-12-hp-100-120v230-vac-single-phase.aspx

1 – Procon V-Band Clamp (clamp to hold the pump on the motor), $6.50
http://www.freshwatersystems.com/p-5309-procon-v-band-clamp.aspx

1 - Blue White F-440 Rotameter – 0.025-0.25 GPM; ½” MPT; Panel Mount (the concentrate rotameter), $67.82
http://www.freshwatersystems.com/p-3607-blue-white-f-440-rotameter.aspx

1 – Blue White F-440 Rotameter 0.1 – 1 GPM; ½” MPT; In Line (the permeate rotameter), $75.51
http://www.freshwatersystems.com/p-3607-blue-white-f-440-rotameter.aspx

1 –NOSHOK Bottom Mount 2.5” Water Pressure Gauge 0-300psi, S.S., ¼” NPT (the pressure gauge), $22.14
http://www.freshwatersystems.com/p-4567-noshok-bottom-mount-25-water-pressure-gauge-0-300-psi-ss-14-npt.aspx

1 -- Pentek 158008 10" Slim Line Water Filter Housing 3/8 Clear Sump No PR (the prefilter), $15.19
http://www.freshwatersystems.com/p-658-pentek-158008-10-slim-line-water-filter-housing-38-clear-sump-no-pr.aspx

1 -- Neo-Pure MB-25098-05 9-7/8" Polypropylene Sediment Depth Filter 5 Mic - 50-Pack, $1.83 each
http://www.freshwatersystems.com/p-102-neo-pure-mb-25098-05-9-78-polypropylene-sediment-depth-filter-5-mic.aspx

50 feet of 3/8” OD LLDPE polyethylene tubing, $12,29
http://www.freshwatersystems.com/p-887-38-od-lldpe-polyethylene-tubing.aspx

5 – John Guest Shut-Off Valve Polypro Male NPTF – 3/8 Tube x 3/8 Male NPTF, $24
http://www.freshwatersystems.com/p-1965-john-guest-shut-off-valve-polypro-male-nptf-38-tube-x-38-male-nptf.aspx

5. -- John Guest Fixed Tee Adapter Polypro – 3/8 x 3/8 x 3/8 MNPT Branch $18.95
http://www.freshwatersystems.com/p-9378-john-guest-fixed-tee-adapter-polypro-38-x-38-x-38-mnpt-branch.aspx

4 - John Guest Male Connector NPTF Polypro – 3/8 x 3/8 NPTF, $10.00
http://www.freshwatersystems.com/p-2974-john-guest-male-connector-nptf-polypro-38-x-38-nptf.aspx

1 (should have ordered 2) – John Guest Right Angle Connector NPTF Polypro – 3/8 x 3/8 NPTF, $3.05.
http://www.freshwatersystems.com/p-3043-john-guest-fixed-elbow-nptf-polypro-38-x-38-nptf.aspx

3 – Dmfit Garden Hose Connector – 3/8” Tube x ¾” Female, $14.76
http://www.freshwatersystems.com/p-1056-dmfit-garden-hose-connector-38-tube-x-34-fght.aspx

1 - Tube cutter, $5.79
http://www.freshwatersystems.com/p-581-tube-cutter-suitable-for-up-to-12-12mm-tube.aspx

NPT brass fittings

1 - 3/8 head plug, $2.98
http://www.amazon.com/gp/product/B0045LRZP8/ref=oh_details_o01_s00_i03?ie=UTF8&psc=1

4 - tees 3/8 female x 3/8 male x 3/8 female (female in middle), $19.36
http://www.amazon.com/gp/product/B006PKKXZ6/ref=oh_details_o01_s03_i01?ie=UTF8&psc=1

2 – 3/8 male x ½ female, $6.24
http://www.amazon.com/gp/product/B000BOAERY/ref=oh_details_o01_s00_i01?ie=UTF8&psc=1

1 – ¼ female x ¼ female, $2.37
http://www.amazon.com/gp/product/B001PNIL48/ref=oh_details_o01_s00_i02?ie=UTF8&psc=1

1 – ½ female x ¼ male, $11.40
http://www.amazon.com/gp/product/B000FMX0Z0/ref=oh_details_o01_s01_i01?ie=UTF8&psc=1

2 – ½ female x 3/8 female, $10.96
http://www.amazon.com/gp/product/B000BO7594/ref=oh_details_o01_s02_i00?ie=UTF8&psc=1

2 – 3/8 street elbow, 3/8 male x 3/8 female, $9.74
http://www.amazon.com/dp/B000BODTKI/ref=biss_dp_t_asn

2 – 3/8 male to ¼ female, $13.86
http://www.amazon.com/gp/product/B000FN1MY0/ref=oh_details_o01_s01_i00?ie=UTF8&psc=1

2 – 3/8 male x ¼ male, $6.30
http://www.amazon.com/gp/product/B000BO6OLY/ref=oh_details_o01_s03_i00?ie=UTF8&psc=1

3 – ¼ male x 3/8 female, $10.26
http://www.amazon.com/gp/product/B000BQUI8M/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1

2 – 3/8 nipple 1.5 inches long, $7.58
http://www.amazon.com/Anderson-Metals-56122-Fitting-Nipple/dp/B000BQW9WU/ref=sr_1_1?s=industrial&ie=UTF8&qid=1400196983&sr=1-1&keywords=3%2F8%22+brass+nipple

2. – Weksler BBV4 needle valves ¼ inch Brass, 600psi from zorotools, $21.74
Purchased on ebay. Amazon.com has something similar:
http://www.amazon.com/Industrial-Grade-5TUL2-Needle-Valve/dp/B004ZRONJI

1. These considerations went into my design:

I wanted it to be mobile because the membrane gets ruined if it freezes. So I built everything on a dolly so that I could wheel it into my house every cold evening.
I wanted the filter and motor to be as low as possible because I wanted the sap to flow down into them with as much pressure as possible.
I didn’t want any major component above the motor for fear that normal operations, such as changing the filter cartridge, might spill liquid down onto the electric motor and ruin it.
The motor had to be on the right side of the dolly so that the inlet of the pump would be out away from the dolly where the prefilter was, and the outlet would be close to the dolly where the membrane was.
The rotameters only work if they are oriented in a vertical direction.


I started with the old dolly, shown in the picture below:

9737

Then I built the frame onto the dolly as shown in the picture below:

9738

2. Build the frame.

I started with an old metal dolly that I had around.
I got the local shop down the road to cut me a quarter inch sheet of steel 13..5” x 32” which I had measured to fit my dolly. If I had it to do again, I would have cut the metal sheet several inches shorter and leave more room on the bottom to make it easier to install the bottom end cap for the membrane housing. For ease of working with the bottom cap of the membrane, the plate of steel should be about 7 inches from the ground and the lowest holes to hold the bolts that hold the pump should begin at 9 inches from the ground. I didn’t know this, but was still able to fit the bottom cap on, but only barely,
I drilled five 3/8” holes into the sheet and into the dolly and bolted the sheet to the dolly using 3/8” bolts that were two inches long. The local shop also cut and bent for me a 3” by 7” piece of quarter inch steel as a prefilter holder. They bent it at a right angle with 2” along one side and 5” along the other.
I drilled four holes toward the end of the long side of the prefilter holder. I used the cap of the prefilter to measure where to drill the holes and I picked a drill bit that would be bigger than the sheet screws that I would use. Then I attached the short end of the prefilter holder to the sheet of steel using two 3/8 x 1” inch bolts.
I also drilled the four 3/8 holes to hold the motor. Two of the holes went through both the sheet and the dolly.
I bought two 2.5” exhaust clamps from a local auto parts store to hold the membrane housing. Then I drilled two 3/8” holes for them into the sheet, one near the top and the other near the bottom. The holes have to be the exact correct distance apart. I was going to use a third clamp, but the holes that I drilled in the middle were not the perfect distance apart. Also, I realized that I only needed two. Note: if you use the PVC membrane housing, you’ll have to use a different method for attaching your membrane housing as a PVC housing needs room to expand when it is under pressure.


I've reached the word limit. I'll continue in the next post...

[HowardR]

3. Attaching electric plug to the electric motor.

I cut the female plug off the end of a medium duty electric extension cord disclosing the three wires inside. The two active wires were white and black and the green wire was the ground.
I stripped about a half inch of plastic off the end of each wire
I took the metal plate off the back of the motor by loosening the two screws that were attaching it.
I loosened the two hex nuts on the poles inside. A better electrician would have attached clips to the wires and clipped the wires on to the clips that are next to the poles.
I found the wiring diagram for the motor online and examined the wiring just to make sure that it hadn’t come prewired for 220 volts. If it is wired for 220 volts and you plug it in to 110 volts, you will quickly fry the motor. (I found the wiring diagram in this pdf: http://www.axeonwater.com/pdf/Marathon_DrawingDiagram.pdf)
I attached the white wire to the top poll and tightened the hex nut over it.
I attached the black wire to the middle poll and tightened the hex nut over it.
I loosened the green screw attached to the frame, and placed the green wire under it and tightened it back up.
I closed the metal plate bringing my wires through gaps. A better electrician would have brought the wires out of the motor through a conduit pipe.
Then I plugged in the motor and tested it to make sure it was set to turn in the clockwise direction required by the pump.


4. Attaching parts to the frame

I attached the pre-filter cap to the pre-filter holder using four self-piercing sheeters (screws) that were 10x1 in size. I had to buy a whole container of 40 of these sheeters. The prefilter cap is attached using self piercing screws, so almost any size of sheeters would have worked, so long as they were not too long.
I attached the membrane housing by clamping it down with the exhaust clamps. Note: Tighten lightly at this point. It will have to be moved up or down later to get the input directly across from the outlet of the pump motor.
I attached the motor using four 3/8 inch bolts along with washers and nuts. Two of the bolts were 2” long (because they also went through not only the steel sheet but also part of the dolly). The other two were 1” long because they only went through the steel sheet.


9740

5. Plumbing the Prefilter

I used ½ inch wide Teflon pipe thread seal tape on every npt fitting that I attached. I wound the tape around the male npt fitting clockwise with the fitting facing me. I put on the fittings in the following order:
I attached the the male end of one of the brass tees (3/8 female x 3/8 male x 3/8 female) into the input end of the pre-filter.
I attached the male end of the other brass tee into the output end of the prefilter.
I screwed both tees in fairly tightly while making sure that the female in the middle would point upward.
On the input brass tee, I screwed in the male npt threads of two John Guest shut-off valves. I screwed in both valves fairly tightly but so that the valves would face outward so that I could easily turn them on or off. The valve that points up is the entrance valve for the sap from my sap tank. The valve that points left is the entrance valve for my lye solution from my soap-wash bucket.
In the middle, pointing upward, of the output brass tee, I screwed in a John Guest shut-off valve. This will be the entrance valve from my permeate tank for the rinse wash. Then I screwed in a straight John Guest male fitting at the end of the tee. (If I had ordered another right angle John Guest fitting, I would have used it here, instead, because it would have made it easier to connect the outlet of the prefilter to the inlet of the pump.)


9741

6. Plumbing the Pump

I screwed in the John Guest tee into the inlet of the pump, I screwed it in fairly tightly while leaving the tee to point up and down. The top end of the tee will connect to the tube from the pre-filter. The bottom end of the tee will connect with the tube for concentrate that is being recycled back into the pump.
I put a straight John Guest Right male fitting into the outlet end of the pump.
I bolted the pump to the electric motor using the Procon V-Band Clamp.


7. Connecting the Prefilter with the Pump Inlet

I cut a piece of polyester tubing and attached it from the outlet of the prefilter to the top of the tee going into the pump. I cut the polyester tube using a little cutting tool purchased from freshwatersystems.com. I simply pressed in the tubes into the two John Guest fittings and they appeared to seal well.


8. Connecting the Outlet of the Pump with the bottom cap of the Membrane Housing

I took one of the end caps for the membrane housing, and attached a John Guest Right Angle Connector to the outer 3/8” hole (the concentrate hole) on the end of the cap. I stopped tightening when it was getting tight and was pointing outward. It will have to be tightened a bit more later.
I then screwed the brass head plug into the center hole of the cap. This is the permeate hole. It needs to be capped at one end so it flows out the other.
Next I laid the dolly down, loosened the exhaust clamps holding my membrane housing and maneuvered the membrane housing up until the John Guest right angle fitting was a straight shot with a short tube to the outlet of the pump.
Next I cut a small piece of polyester tube to go between the fitting on the outlet of the pump and the John Guest right angle fitting on the membrane cap. I slid the membrane housing up out of the way while I connected them.
Next I put two of the four O-rings supplied with the membrane housing on the end of the membrane cap. Then I inserted the membrane cap into the housing. This is easier said than done. After struggling with it for a little while, I got some olive oil and coated the outside of the O-rings and the entrance t the housing with a bit of olive oil. Then I was able to slide the cap into the membrane housing.
I also had trouble fitting the clamp to attach the cap to the membrane housing. The trouble was that there was a slight separation between the ridge on the housing and the lip of the cap. I wasn’t able to push the cap all the way in, due to the awkward position where I was working, so I needed the clamp itself to pull the ridge of the housing and the lip of the cap together. I was able to do so by positioning one side of the clamp so it spanned both lips and then pressing down with my finger on the middle which slid it into place. After that it was easy to insert both bolts.
Then I tightened the exhaust clamps so that the membrane housing would be firmly attached to the frame.


to be continued in next posting...

[HowardR]

9742

9. Plumbing the recirculation line from the off-center hole of the top cap of the Membrane Housing. The center hole is for permeate (pure water). This off-center hole is for concentrated sap.

I attached a 3/8 brass street elbow to the top concentrate port (the 3/8 inch female that isn’t in the center). I tightened it, but still insuring that it pointed outward.
Then I screwed in the male end of a 3/8” brass tee which has a male on one end, a female on the tee part, and a female on the other end. I attached the male end into the street elbow. But I didn’t yet screw it in hard. This tee will eventually hold the gauge, so it should eventually point upward.
Next I attached the male end of another identical 3/8” brass tee into the first tee. Again, I didn’t screw it in hard. This tee will eventually point horizontally toward me. The concentrate will flow out of the system through the middle hole of this tee.
Next I attached a brass adapter to the female end of the second tee. The adapter goes from 3/8” male to ¼” male. Again I didn’t screw it in hard.
Next I attached a needle valve which has two ¼” female npt threads and an arrow on it which shows the direction of flow. I didn’t notice the arrow the first time and had to take it off and redo it. Again, I didn’t screw it in hard.
Next I attached a ¼ male to 3/8 female brass adapter.
Then I screwed in John Guest Male Connector.
Then I tightened the whole line of pipes up together starting with the outside pipe. My goal was to have the needle valve point up at the end, the outside tee point horizontally toward me and the tee for the gauge point vertically upward.
Then I attached an approximately 53” long piece of polyester tube from the John Guest Male Connector fitting down to the bottom of the tee at the input to the pump. This is the recirculation line.
Then into the pointing up vertical tee closest to the cap I screwed in a 3/8” male to ¼” female brass adapter, but I didn’t screw it in tight. Next I screwed in the gauge which has a ¼” male npt. Now I screwed in everything tightly, making sure that the gauge would point toward me for easy reading at the end.


10. Plumbing the concentrate outlet line.

The concentrate outlet line starts in the second tee (from the upper cap) in the recirculation line. Right now, there is an empty female npt fitting pointing toward you in that tee.
Before I screwed everything together, I attached it all together, otherwise there wouldn’t be enough room for the needle valve stem when tightening. First, I attached a 3/8 inch brass nipple.
Into that brass nipple, I attached a 3/8 inch brass street elbow pointing to the right.
Into that street elbow, I attached a brass 3/8 inch female to ¼ inch male adapter.
Into that adapter, I attached a needle valve, making sure the arrow pointed in the direction of flow.
Into the needle valve, I attach a ¼ inch male to 3/8 inch female adapter.
Into that adapter, I attached a 3/8 inch nipple.
Into that nipple, I attached a 3/8” female to ½” female adapter. (These last three pieces could be replaced by a single ½” female to ¼” male adapter.)
Into that adapter, I attach the concentrate ratameter which needs to be vertical.
Coming back in the other direction from the top of the ratameter, I attach a ½ inch female to 3/8” female brass adapter.
Into that adapter, I screwed in a 3/8” John Guest Male fitting.
A tube will be attached to this John Guest fitting which will go into the concentrate tank to be boiled up as maple syrup. That tube will end with a John Guest shut-off valve which will be weighted down with a couple of extra 3/8” brass fittings that I ordered by mistake, so that it will stay in the permeate tank.


11. Plumbing the middle hole of the top cap of the Membrane Housing

The middle hole is for the permeate (pure water) output. I attached the following fittings going straight up from the permeate hole in the center of the top cap.
The first fitting was a brass adapter 3/8 male to ½” female.
On top of the adapter, I attached the permeate rotameter which has a half inch male fitting at each end.
On top of the rotameter, I attached a brass adapter which went from ½” female to 3/8 inch female.
On top of the brass adapter, I attached a John Guest Male Connector.
A tube will be attached to this connector which will go into the permeate tank in order to save permeate for rinse water. That tube will end with a John Guest shut-off valve which will be weighted down with a couple of extra 3/8 brass fittings that I ordered by mistake, so that it will stay in the permeate tank.


12. Inserting the membrane into the membrane housing and closing the top cap.

Next I inserted the membrane element into the membrane housing. Again I used a bit of olive oil on the big O-rings. (I also put a bit of olive oil on the little O-rings inside the cap. Then I wiggled and pushed the membrane down so it fitted into the lower cap. Then I pushed on the upper cap. This time it went all the way down, partly because I was pushing downward and could exert more force. Then I put on the clamps, covering the motor with a bit of cardboard so that the nut and washer wouldn’t accidentally fall into the motor.


13. Finishing things up

Then in the prefilter, I unscrewed the Slim Line Water Filter Housing bowl from its cap and inserted a 5 micron filter cartridge (the Polypropylene Sediment Depth Filter) into the prefilter.
Then I cut a bunch of short polyester tubes and attached the fittings that will go on the much longer polyester tubes that I will cut to size next spring. The tubes that go into the top of the permeate and concentrate tanks have John Guest valves on the end, so that I can shut them off to make the RO air tight when it is being stored. At the end of those valves I will screw in a couple of extra 3/8" brass fittings that I purchased to weigh them down to keep them from popping out of the tops of the tanks to which they are flowing.
The input tubes that will draw from my bulkheads near the bottoms of my sap tank, my permeate tank, and my soap (lye) bucket, all end with Dmfit Garden Hose Connector fittings that will be screwed in to those bulkheads.


Next spring I will be trying everything out, first using spring water. I will also be redoing my set-up for receiving sap in order to maximize the drop from the bottom of the sap tank to the prefilter. (The permeate doesn't have to have as much of a drop since its inflow line bypasses the prefilter.)

I'll post again here to report my experience. If anyone else puts together an RO using Bowhunter's design, I hope that they post pictures of their systems here also. Perhaps we can share ideas for improvements and also share reports about how well they work.

[HowardR]

Mistakes in my design:

I've been running my RO this spring and it works great. I've been running it at 85 to 90 psi pressure (at my gauge) and have been getting rid of about .20 to .25 gallons per minute of permeate. I have also discovered a few things that I should have done differently:

1. I ordered the wrong pump. The pump I ordered was one with a 130 psi relief valve. This limits the amount of pressure that I can put on my membrane. I could have saved $30 and enabled higher pressure simply by ordering the same pump without a relief valve. Here's the webpage of the correct pump:

http://www.freshwatersystems.com/p-5294-procon-pump-nsf-brass-w-188-double-flat-drive-140-gph-38-npt.aspx

2. When constructing my RO, I did one step out of order. Specifically, I should have done one of the parts of Step 8 before I bolted the pump motor to the frame. By the time I got to Step 8, I didn't have enough room between the pump and the membrane to insert a large enough piece of polyester tubing between the outlet of the pump and the John Guest right angle fitting on the membrane cap.

As a result, when I tried out my RO this spring, I had a leak in one of the connections of that small piece of polyester tubing. In order to stop that leak, I took off all but the top left bolt holding the motor to the frame, and slid the bottom of the pump toward the membrane. That stopped the leak, but the pump motor no longer lined up with three of the holes that I had drilled. As a stopgap, I used a temporary clamp along with the one remaining bolt to hold the motor on the frame. I'll probably take off the pump during the offseason and insert a longer piece of polyester tubing so that I can bolt down the pump with all four bolts.

3. I ordered the wrong floatometer. I replaced the floatometer for the permeate line with one that is just like the floatometer of my condensate line (which reads up to .25 gallons per minute). The new floatometer lets me see more precisely how much permeate I am getting. I know to rinse or wash when the flow of permeate falls below .2. Also, with identical floatometers on both lines, I can compare, at a glance, the flows that I am getting of permeate and condensate.

By the way, I've been in touch with Bowhunter by email, and he has been very helpful. For example, he looked up my membrane and gave me advice about how much lye I should use during the lye wash. The membrane that I ordered must be washed at a lower pH and temperature than normal. In an email to me, he wrote, "For an NF3 the lye wash is done at 11 pH and 95 F."

[HowardR]

Here's how I cared for my R.O.'s filter:

1. Rinsing. While running, I would collect 40 gallons of permeate water while discarding the rest. At end of each day, I ran the permeate through the machine with both needle valves open. The next day, first thing, I replaced the filter cartridge. One late-season day, I did an extra rinse and replaced the filter cartridge mid-day.

2. Washing.

I did three washes this year:

First, I did a short rinse (about 3 minutes).

Second, I filled a 5 gallon stainless steel pot that had a bulkhead near the bottom with 4 gallons of permeate water mixed with 1/2 teaspoon of red devil lye (creating a pH between 11 and 12) and heated it to a maximum of 109 degrees. This is a higher pH and temperature than that recommended by Bowhunter, but is within the maximums according to the spec sheet (http://www.freshwatersystems.com/specifications/axeon-nf3-spec-sheet.pdf) for this membrane.

Third, I ran the lye-water mixture through the machine for 20 minutes, recirculating by putting both the permeate and condensate outlets into the 5 gallon pot. While washing, I alternated between running it with the valves fully open and running with a bit of pressure. The temperature of the lye-water cooled by about 10 degrees during the recirculation.

Fourth, I rinsed for about 15 minutes with the remainder of my permeate water. During the rinse, I used a bit of the exiting permeate water to rinse any remaining lye-water off the outside ends of the permeate and condensate lines, so as not to contaminate the permeate and condensate tanks with a few drops of lye water.

Finally, I replaced the used filter.

3. Storing. At the end of the season, I washed my membrane (see "Washing" above). Then I made a storage container out of a 4 foot piece of 3" PVC pipe with caps on each end, with one cap having a screw opening in it. I took out my membrane (had to use a couple of needle nose pliers to pull it out of its housing) and put the membrane into the storage container. Then I added a gallon of solution made out of permeate water with 1 1/3 ounces of sodium metabisulfite, a preservative that is used in wine and beer. Next February I will run at least 40 gallons of spring water to clean the preservative out of the membrane before I start feeding the maple sap.

[HowardR]

Because I bought the wrong pump (the one with the pressure relief valve), I was not able to bring my pressure over 100 psi. (Bowhunter runs his similar machine at pressures up to 250 psi.) I usually ran it at 85 psi, a pressure at which the R.O. ran quietly without any straining. At that pressure, I usually got .2 gallons of permeate per minute. If I had bought the right pump (which would have cost $30 less) I could have increased my pressure and thus my permeate flow.

Due to the cold nights this maple syrup season, I had to roll the entire RO inside the entrance way of my house almost every night to guarantee that it wouldn't freeze, and I had to wait in the morning until the temperature outside got above freezing before I rolled it out again. So I generally only ran it about 12 hours per day. That was enough to keep up with this year's sap flow. If there were a big run with the weather staying above freezing all night, I could have kept it running 24 hours a day.

During the peak runs I usually ran it at a 1:1 ratio (.2 gallons concentrate, .2 gallons permeate) and it enabled me to keep up with the sap flow. It would easily run for 12 hours without much change in the permeate flow.

During the late season, I ran it at a 1:4 ratio (.05 gallons concentrate, .2 gallons permeate), and it made it worthwhile for me to keep boiling down the low-sugar sap. (Last year, I quit boiling when 100 gallons of the late season sap only boiled down to one gallon of syrup.) The membrane gradually got dirty, reducing the permeate flow to about .15 gallons per minute. One time, this caused me to do an extra rinse after just 4 hours of operation.

I'll probably replace my pump with the right one next year. Then I could increase the pressure and the permeate flow while reducing the concentrate to permeate ratio.

[DASH]

Thanks HowardR! this information is just what I've been looking for and you have laid it out perfectly.

Thanks to you and Bowhunter I'm going to try my hand at building one!

[HowardR]

The main thing that I learned this year was when I had to replace my filter cartridges. Last year, I replaced them at the beginning of each day. This year, I only replaced them when the filter cartridge was slowing down the sap flow. I could tell when that was happening because I would start getting little air bubbles that were clouding up the condensate floatometer. I actually only used 5 filter cartridges this season.

By the way, I've heard from several people who were going to build the Bowhunter design RO this year, except with larger membranes that had more capacity. I hope they post their experience here in this thread.

[upsmapleman]

one problem with saving your filters to they get really plugged. They harbor lots of bacteria which grows over time and spreads it to you fresh sap.

[HowardR]

I just learned about another annual maintenance task that I should have been doing, but wasn't. When I plugged in my RO this spring, the motor would only go around slowly and jerkily. The problem was that the pump was stiff and the motor wasn't strong enough to make it go around. There are two holes on the pump (similar to the oil holes on a furnace fan). Once they were oiled, the RO worked fine. From now on, I will oil the pump before and after each season.

[HowardR]

Acid Wash

I just learned about something else I should have been doing. My membranes have gradually been declining in how much permeate that they were pushing through. After 6 seasons of use, my oldest membrane was just pushing through half the amount of permeate that it did when it was new. Turns out that I should have been doing an acid wash at the end of each season. Some people actually do an acid soak, not just a wash. There are directions for doing it in this thread (http://mapletrader.com/community/showthread.php?34091-Acid-wash-on-homemade-RO). I bought a pound of Milliard Citric acid online, and am about to do my first end-of-season acid wash.

Bowhunter recommends using 2/3 of an ounce of citric acid powder per gallon of water, and he has a membrane similar to mine. So I'll add 5 tablespoons (2 and 2/3 ounces) of citric acid powder to 4 gallons of water and conduct the acid wash starting at 95 degrees (http://mapletrader.com/community/showthread.php?23464-Acid-wash), about the same way that I conduct the lye wash. The only difference will be that I will let my membrane soak for at least 4 hours after the wash. Then I'll do the last rinse and put the membrane away in a frost-free place until next season. My plan is the following:

1. Rinse with permeate water for 10 minutes (just after pushing through the last sap of the year).
2. When I'm ready, I'll do a lye wash for 20 minutes
3. Immediately after, rinse with permeate water for 10 minutes
4. When I'm ready, do an acid wash for 60 minutes at 95 degrees.
5. Let membrane soak for at least 4 hours.
6. Rinse with permeate water for 10 minutes.
7. Put membrane away until next season (in sodium metabisulfite solution).

I would rinse longer and maybe conduct a second lye wash, but my permeate tank is just 65 gallons and I have two ROs, so I wouldn't have enough water to do much longer rinses.

[bowhunter]

I've just finished my season and cleaned my membrane for storage. I was able to improve my permeation rate by about 10% by doing a citric acid wash after doing two soap or lye washes. I measured the permeation rate at the beginning and end of the acid wash. I do an acid wash about every other year but I haven't always been able to see any improvement. The acid wash is 2 1/2 ounces of citric acid in 4 gallons of water. The acid wash pH is about 2.5. I did the wash at 80 F for 6 hours, at 70 psi and about 2 to 1 permeate to concentrate.

After 6 years my membrane is performing above the new rating and very close to what I measured when it was brand new. It's a NF270 Axeon knockoff with an original rating of 850 gallons per day of permeate at 70 psi, with 77 F permeate and a 15% recovery rate. When I finished cleaning this week, it tested at 937 gallons per day. I ran the test on 55F permeate so I had to adjust the flow to 77F. You can flow test your membrane at it's rated pressure and any temperature permeate by using a temperature adjustment factors. All membranes use the same temperature adjustment factors and you can Google them. You have to measure the permeate temperature to adjust the flow to the standard temperature. Standard home ro membranes are rated at 50 psi, nano-filtration membranes are rated at 70 psi, Filmtec XLE's are rated at 100 psi and I believe the MES membranes are rate at 125 psi. All membrane permeation rates are very sensitive to temperature and it has to do with the viscosity of water at any given temperature. As a general rule the permeation rates decreases 3% per degree F below 77 F.

As an aside I always run recovery at 15% or less when I'm processing sap. I wash the membrane with permeate for an hour at the end of each day. I never do a soap wash until the end of the season. I always do a warm water flush (less than 100 F) before I do a soap wash. A lot of the higher molecular weight sugars will dissolve in the warm water and not consume so much of the soap if you can rinse them off first. Based on what I'm seeing this year I'm convinced you can probably get 10 years or more out of a membrane in maple sap service with proper operation and cleaning.