Home Made RO

[Teuchtar]

Call me cheap, or frugal, but I'm the next guy to put together my own RO.
I have the membrane (Filmtec 4" NF90-4040), pumps, flowmeters, valves and fittings.
Need to pick some experienced brains for a few of the details.
Sorry, I got no money left to pay you, but I can share my results.

1. Cleaning: How big should the solution tank be, and how long to circulate ? Should the cleaning solution be mixed/diluted with permeate , or do you just leave that small amount to circulate ? For how long ?

2. Flushing: I understand you would save back about 1 hours permeate to flush. Do you flush in the forward direction, or is the flush in reverse flow ?

3. How long do you usually run the RO before you go into rinse mode ?

4. Does anybody have an operators manual for a similar size small unit that they'd be willing to share with me ? Any make, any language.

Hoping to have this thing put together in the next couple of days and get her tested on some new sap.

Like I say, I'll be happy to share my results with the group.

[Teuchtar]

Thanks to those that PM'd me.
I think I now have the info I was looking for. Hope I get this thing put together before the Big Run.

[Gary in NH]

I also have similar questions on cleaning. If anyone has info for cleaning Filtec membranes they could post or PM that wouod be appreciated. I have been using Airable RO soap and it seems to work. I check pH of rinse water to verify it's all flushed out but I'm guessing on ratio to cleaner and water when I run it through.

Thanks in advance,

Gary in NH

[skinny78]

Teuchtar,

Hows the ro building? Have you started using it yet?

[DanE.]

Hi, I was wondering if there is any update on your home made R/O. how you have it set up, how well it worked, what results you get, etc.... Thanks Dan...

[Teuchtar]

My RO certainly works better this year than last year. I set it to produce 30 gal per hour of concentrate, and 60 gal of permeate. So it gobbles up 90 gal per hour. I am still limited in pressure, with my peak pressure only at 240 psi. I'd like to push that pressure up to at least 300, but that can wait until next year. The RO vessels are rated 300, and they look like they'd go off like a bomb if the ends let go.
I've been absolutely inundated with sap this year. I added taps and improved my vacuum. I took time off work to process the sap. So I have not had time to tinker with the design. I'd like to add some features, like a low pressure cut out and plumb in the wash tank more professionally, with a heater etc.
I'm following the advice posted on this site, flushing at four hours with 50 gal, and washing with sodium hydroxide at 12 hours. That gives good results.

[twobears1224]

is teughtar still here? i sure would like to know how his homemade ro worked out and details on it.i,am looking into building my own.

delbert

[chrisnjake9]

I'm chomping at the bit to on the home made ro there is also a guy on the site hodge says he has built one id like to hear how his project went also share some knowledge guys

[Teuchtar]

I think I told you that I was kinda ticked off early in the season with the low concentrate flow. Well, I found the Procon pump relief valve setting was low, in fact, the screw had dropped out. After a 5 minute tweak, I got the pressure at the feed pump up to 150psi, and that gives me 340psi at the membranes. Now, I can process over 2gpm of raw sap. Naturally that flow does drop off as the membranes are worked, and as the concentration rises. But flushing and washing restores performance.
I'm still cleaning tanks, and bottling syrup, then I've got to flush my lines. Like most guys on the 'trader, I'm just about out of Maple Enthusiasm for this year, but I will get round to publishing pictures.
In summary, here's some of the vital statistics of the Prestidigitizer(tm):
Membranes: 2 NF90-4040
Feed Pump: 3/4 hp Procon 215gph @ 150psi. Draws sap from the reservoir and pumps through the 5 micron filter.
Pressure Pump: Gould 1.5 HP multistage 215 gph @180 psi. Picks up sap downstream of the filter and forces it through a needle valve.
Recirculator Pump: Grainger 2 HP 16gpm @ 16psi. Picks up sap from the pressure pump, and spools it repeatedly through the membranes concentrate side.
From the membranes, you need another needle valve and discharge that spooled concentrate through a rotameter out to your concentrate tank.
From the membrane permeate side, add a rotameter, then out to your permeate tank.
The membranes and housings come from Atlantic RO.
Stainless fittings come from buyfittingsonline.com
Pumps, motors, rotameter, valves, all come from eBAY (buyer beware !!!)
Hose, clamps, etc, comes from McMaster-Carr.
Drips, leaks and blown fittings are all part of the learning experience.

Total cost: A fraction of a commercial unit, but took many hours to get it right.
Photos etc to follow (be patient, I had to get caught up with taxes, mowing, kids in college, and, oh yes, my other job)

Teuchtar

[jrthe3]

after all the fishing is done and i ready to get back to maple i going to start work on my own ro i have gathered a lot of info from this board and its menbers i will post as much as i can of my ro when started

[Teuchtar]

Here is the piping schematic

[Teuchtar]

Pump arrangement:
Grey pump is M1
Blue pump is M2
Black pump is M3

[Teuchtar]

Piping arrangement:

[Teuchtar]

Membranes and filter:

[DanE.]

wow. this is great! Thanks for posting. Dane

[KenWP]

So what percentage of sugar does it bring the sap down to. If a guy could get down to 4% you would have lost half the water already. This may sound dumb but could a guy make a gravity system useing one of the membranes. Some how fill it up and wait till tomorrow and have even a 1/3 of the water go through .That would shorten up a boil a lot even.

[Teuchtar]

At 340 psi I have driven the sap as high as 16% by recycling back to the sap tank. But such high concentration fouls the membrane too fast, and is not so efficient overall. On a single pass, I can get up over 7%.
I suppose the cutoff of efficiency is when the RO is down to below 0.5 gpm of permeate it makes sense to continue to concentrate. This is just below the boiling rate for a 2x6. Go much lower than that, and I'm better to start up the evaporator.
I suppose you could just pick up a membrane and its housing and use gravity feed to drive the sap through. But unless you were on a good hillside, the performance would be very weak, and you'd be down to a trickle after only a few minutes of concentrating.
Those small 1/4hp carbonator pumps are so cheap and plentiful, you would probably want to think about that as a minimum instead of gravity. To get 300 psi, you'd need 700 feet of vertical rise, that might be 1/4 mile up the mountainside. At that point, the piping costs way more than a pump.
I'm not sure what is the ideal system pressure for 4% concentration. There's a couple of RO's on the market that make such a low concentration, but I think most people prefer to get higher concentration, which means more pressure and more recirculation. Bear in mind that the permeate flow is always dropping (since your last wash), so you soon get tired of watching that trickle.
Brent tried the GE merlins, which are essentially an RO driven by city water pressure, but I believe he needed to add a pump to help the sap along, and to flush and wash too.
Last year was my first year using this machine. I added the recirculator pump this year to boost the membrane flow. They seem to be happy with 8gpm on each membrane (16 gpm at the pump for twin towers).

[twobears1224]

thanks for the pic's and info.last night i got on the membrane website which tube did you use?? i see they have a bunch of diffrent ones.

delbert

[Brent]

there's no free lunch

if you need to pump the sap up 700 feet to get the pressure in the column,
forget about plumping up the hill because you'll already have the 300 psi pump to make it go up.

[Teuchtar]

I picked up the 4040 Stainless vessels. Good for 300 psi. Maybe not quite as good for 340.
Who needs a pump to go up the hill ? Thats one more good reason to need a new ATV or snowmobile.

[twobears1224]

TEUCHTAR:could you give us some info on running your ro?? like,i've said before i,am new to them and i,am curious.
i,am wondering how you get one going,what pressures should be/run,ect.
i,ve looked at both membranes.the ones you used and the merlins.pricewise your better off going your way..those merlins are pricy in my opinion and alot smaller.
i have a fairly new submerible water pump.the waterline connection got busted because the pump wasn,t put in the casing right.i,am wondering if i could use it some how as the recirulation pump?? i read that CDL?? had theres inside the membrane casing and guys liked it that way.

delbert

[DanE.]

thanks for the pic's and info.last night i got on the membrane website which tube did you use?? i see they have a bunch of diffrent ones.

delbert

Hi, Would you be able to share this information. thanks Dan...

[KenWP]

there's no free lunch

if you need to pump the sap up 700 feet to get the pressure in the column,
forget about plumping up the hill because you'll already have the 300 psi pump to make it go up.

Would be hard pressed to find a hill around here anyways. Flat as a table around my place. You couldn't even run garvity lines here without being way up a tree on the far end.
I guess I need to invent a freezer unit and RO sap by freezeing it.

[twobears1224]

DAN:IS THIS WHAT YOUR LOOKING FOR?? formembranes.com

delbert

[DanE.]

Thanks. I'm going to have lot of RO operations quesitions in the next few weeks.


Dane

[Teuchtar]

Twobears:
To operate my RO, its just about like any other....
Connect the inlet hoses (one to sap tank, one to permeate). Use 3-way valve to select which tank.
Connect the discharge hoses (one to concentrate tank, one to permeate). Don't let the concentrate hose fall on the ground (another stupid mistake I made)
Back off the membrane pressure valve
Start the feed pump and flush out mostly all the air until the concentrate line is running "solid" water. Membranes don't like to RO bubbly sap.
Start the recirc pump to flush the membranes even more.
Close down the feed valve to limit the boost pump pressure surge
Start the HP boost pump and open the feed valve to allow it to prime (usually it starts up airlocked)
Close down the membrane pressure valve to raise pressure in the membranes up to 340 psi. Adjust as necessary to maintain concentrate/permeate balance the way you like.
Let 'er rip for four hours, then flush with permeate for 15 min or so, then back to concentrate.
Its less complicated than it sounds.

For the soap wash, I reconnect the sap line to a separate 15g tank. Set up about 10 gal of warm water at pH-11 using RO soap. Connect the concentrate hose back to that tank. Run the circ pumps to circulate the soap solution for 15 minutes at no pressure or until it feels warm. The pumps heat the soap, no need for additional heater elements. Then dump the hydroxide soap and rinse with plenty of permeate.

That recirc pump is exposed to the full 340 psi casing pressure. A common submersible pump might not like that kind of abuse, since the casing is intended to normally run between 0psi and 30-50 psi. The high pressure coming off the boost pump might rupture the casing, or fail the seal from high impeller thrust.
Not saying it won't work, but you'd need to evaluate the risk etc. Don't run the machine in your kitchen ! For the recirc pump I chose a really brutal dayton-grainger stainless process pump which I got as a new orphaned discontinued model. I chose a high flow (16 gpm if I remember) and 75 foot shutoff head, then a throttle valve to control the pressure drop down to 16psi differential, which Dow says is the max delta-p to get maximum flow through the membrane. Goulds make really nice pumps, and have models suitable for both the multistage boost, and the recirc. Grudfos also. Both are a bit spendy, but publish lots of good application help, and their dealers are very helpful with questions. Lowes/Homedepot/TSC are not in the same league.
Choosing the right pumps is a tricky process and it took me months to iterate the design. This machine uses 3 pumps back to back. The first pump is a procon gear pump who's flow doesn't vary much with pressure. The second pump is a multistage centrifugal pump whose flow is set by the first pump, and whose discharge pressure is a function of its flow-head curve. You need to obtain the flow head curve for each pump you use, make sure they're matched to the job. The Dow Filmtec application manual tells you the feed flow and pressure limits for the membrane you've chose. Then you need to make sure that the feed/discharge pressure of each pump steadily builds and doesn't drop below atmospheric when you start the pump, otherwise it gets airbound, and draws in all kinds of air at the seal. I put a throttle valve after the second pump to control its discharge pressure, and be able to bring the suction back above atmospheric to allow it to prime. The pressure gauge at each pump helps too understand whats going on, but not really necessary.
If I was to build RO's commercially (tempting !) I'd replace pressure gauges and valves with a couple of flow control orifices, and make the machine easier to use.

I think you're right about CDL, they put a whopper big pump in the RO tower to drive the recirc flow. There's another one that uses the last few stages of the HP Boost pump to drive the recirc. You can usually glean info from their Patents, just do a google search and shazzam --- full disclosure !


Ken, I didn't realize your place was so flat. I'm at the bottom of Sutton mountain. No flat land for miles around me.

T

[Teuchtar]

Here's some better quality photos.

http://www.flickr.com/photos/duncan_kathy/

[Teuchtar]

Dan:
Those are the 4040 Stainless pressure vessels from Atlantic.
http://formembranes.com/PV.pdf

[Sugarmaker]

Teuchtar,
Wow, nice job on the homemade R.O.! You have done a lot of research.
More taps in the future?

Regards,
Chris

[twobears1224]

TEUCHTAR:thanks for the writeup..i,am new to ro,s and it helped alot.one question.i noticed some small copper lines on your ro..what are those for?? pressure guages??

delbert

[Teuchtar]

Delbert
Yes, you're right. Those 2 copper lines read the pressure across the membrane, concentrate side.
According to Dow, you can apply a maximum flow of 16 gpm through the concentrate side of the membrane. High flows are better, in that this reduces the rate of fouling. I don't have a flowmeter there, so I chose to measure flow using a differential pressure gauge. Dow specs say to limit that pressure drop to 15 psi (higher pressure drop implies more flow). I calculate a couple more psi drop for the elbows and tee's, and in operation , I set the valve V5(thats a simple blue gate valve on the M3 pump discharge) to read the 16 psi differential. I've loaded an updated piping diagram to Flickr, since the first rev'n of that drawing omitted it.
Photo 24 shows the gauge, lying loose on the deck between two pumps.
In next year's version of the Prestidigitizer, I'll need to make a proper operating panel and mount the gauges and flowmeters to it.
Refer to Dow 609-0071 table 3.6 "Fiberglassed 4040"

[Teuchtar]

Just noticed the tiny footnote in the table saying "recommend 20% below the maximum for new/clean elements", so perhaps I'd better back off the 16 psi to 13 psi. Either way, at the end of the season I checked the membranes for erosion and tearing, and saw no sign of any distress.

[Teuchtar]

Chris,
Thanks for the kind words.
In January, I added 300 more taps, in expectation of needing more to feed the machine.
I think I'll stop at this number for a while, and concentrate on boosting the sap per tap with better vacuum and pipelines.

T

[Grade "A"]

Teuchtar, you did a great job. I have been looking into what it would take to build one. I'm glad you posted how you made it and how well it worked, it's gives me the extra push to make one. I have put two merlins like Brent's together but I would like to add a bigger membranes and bigger pump.

[OhioMapleMan]

What do you think you have in the total system so far. This is really gettng my interest. I keep looking at some systems my friends have but the cost is killing me.
Thanks Roger

[SWEETER CREATIONS]

Italked to the waterguy, trying to purchase 5000gallon per day RO. I dont quite understand how to figure calculations and he dosent either. He uses his for bottled drinking water just the opposite of maple producers. If I have 1000 gallons of 2%sap what will the yield be reduced to at 8% sap ?

[KenWP]

250 gallons if you went from 2% to 8%. 2-4 would be 500. 4-6 334 and 6 to 8 would be 250. If my calculations are right. Somebody will come up with something different.

[Teuchtar]

Anybody know of a source of high pressure food-grade hoses ? I like Synflex hose and I need a hose supplier to make me up a few hoses with stainless fittings. Don't want to buy a whole 250 foot reel in order to get the 20 feet I need.

Duncan

[SWEETER CREATIONS]

Thanks for the calculations. New to the world of RO"s do you clean them every day with soap or just rinse ? Like I said I"m new to this never in my wildest dreams did I think I would buy an RO. I"m sure you"ll see alot of me here asking some stupid questions. thanks for all the help .

[WESTVIRGINIAMAPLER]

Might check www.usplastics.com

Good company, good customer service and ship fast and you can usually buy in 10' lengths if they have what you want.

[jrthe3]

teuchtar if that don't work for ya pm me and i can give you a guys name and number here in erie pa that would work with ya

[Teuchtar]

Erie PA !!
I used to make locomotives in Erie PA. Best fun I nearly ever had.
I'm going to take you up on that offer. I haven't found a good source of 34PW hose yet.
(good=cheap)

[jrthe3]

oh di you work at ge

[trackerguy]

I like the modular design and bolt together frame in one of the pics - is the frame material a home depot item?

[Teuchtar]

A couple of RO upgrades implemented this past couple years to report on:
1) I've gone from 1 membrane to 2, and now to 4 membranes. Two are NF90-4040. Two added this year are XLE's. All come from Atlantic
2) Added pushbutton control and relay logic to bring on the pumps. The HP and Recirc pumps are interlocked with the feed pump. Relays are 120v ac with led indicators.
3) Pressure switch set to kill the system when the bulk tank runs dry.
4) Membrane Vessels mounted vertically but pivot down on a hinge to allow horizontal loading. Much easier !
5) PID temperature controller interlocked with the pumps to kill the flow when temp reaches 75deg on flush, or 95 on 12pH wash cycle. (Auber instruments)
6) Flowmeters, gauges and membrane pressure valve moved onto the control panel. Tidies up the machine a little.
7) Differential pressure gauge monitors the filter fouling to be sure its not too dirty. Orange Research.
8) Inlets/Discharge cleaned up and moved to be accessible from front of machine.
9) Membranes are plumbed two in parallel, with two on each string. Achieves Concentration ratio of 3.5 on fresh cold sap. I might try 4 in series to get higher concentration.
10) I tried Brent's idea of warming the incoming sap to 110F on experimental basis. Two sources of identical sap, one heated from evaporator. Switched from one tank to other with three replicates. When running hot sap, yes the permeate passage really increases, but so does the sugar carryover. Bad idea. Loose too much sugar, and the concentrate spoilage rate skyrockets. I prefer to add the extra membranes in series.
11) I changed my RO practice to first make a pass of the entire bulk tank with membranes at 200 psi. That concentrate goes to a secondary tank. Then make a second pass of that tank to bring it up to 10-12% at 300 psi. Takes much less time, concentrate production is more continuous, and heating of the concentrate minimal. Plus I can boil straight off that second pass at same rate the RO produces. My previous method was to return the concentrate to original tank, but I found the concentrate is dense, sinks directly to the bottom of the tank, and right out the suction pipe back to the RO. Better and faster to concentrate the weakest sap first.

[Teuchtar]

Checking through those old questions from 2010, I missed answering the question on high pressure hoses. The best supplier for custom 1/2 hose is Leader. They will crimp fittings on 34PW hose for a good price. So I've upgraded my machine to Eaton 34PW for all the pressure lines. I've seen some of the commercial hobby RO's, plumbed with truck airbrake line, which just doesn't sound like Tim would approve, no way.

The frame actually is constructed of Home Depot punched angles, bolted up to a wooden base for the motors and pump. Looks like H--- but is functional and cheap.

[jrgagne99]

Can you post an updated picture Teuchtar?

[Teuchtar]

Updated (2013) photo of the 4x4040 membrane Prestidigitizer is now loaded to my Gallery.
The P&ID in there is a couple years old. I'll update it sometime for the differential pressure gauge and series membranes.
If the wiring diagram would be useful, let me know. Its an ugly hand sketch.

[childsr2]

Thanks for the update. Your posts have been most helpful with my design. Here is my adaptation.
I've rebuilt an old Small Bros. RO. I bought it in terrible condition at auction for a few hundred. The original design had a 5 hp pressure and a 1hp feed pump on five vessels. I salvaged the frame, vessels, and and furnas controls. I bought a 3/4hp burcam booster pump for my feed, a 2hp procon 660gph high pressure pump, and a pompco wgs 1.5hp 12gpm recirculating pump. The 4" vessels hold two membranes each. I bought four H2O 70-4040 membranes. I'm running the two vessels in-parallel.
I can generate 250 psi and have so far processed two 800gal batches of ~2% sap @225psi (I'm bleeding a little back to my feed pump). I'm going through about 325 gal sap/hr and making about 75 gal/hr of 8% sap with a 3/1 ratio.
I'm using a Square D pressure switch and I have one Leader 3/4" $300 hose on my high pressure pump. I hard plumbed my recirculation pump to save money. There is website called valvesandinstruments.com that has braided T321 stainless hose for about $50 each that I'm looking into.
I'd like to add temp control and would appreciate any information on it.

[Jallen]

A wiring diagram would be awesome I would like to add a low pressure and temp shut off to my machine

[Flat Lander Sugaring]

very good info