Plumbing my RO

[TunbridgeDave]

I finally got the electrical problems fixed on the old Sap Brother, so it's now time to figure out how to do all the plumbing in the sugarhouse but I'm getting 2 conflicting ideas on how to set it up.

The first was to send the concentrate to a separate tank only squeezing it part way, and then taking that and squeezing it again to a third (feed) tank for the arch. This way you're not pushing the membranes and it will take less time to run it through twice then it would to highly concentrate in one pass.

The other method is to return the concentrate to the first holding tank and just keep concentrating it. It's a much simpler setup but there's the idea of consistancy to worry about. It would be nice to boil the same concentration (8% or whatever) all the time. There's the issue of spoilage due to the heating of the concentrate but if you're running it back into the tank with fresh sap comming in all the time, that will help keep it cool. Also, this rig doesn't seem to heat the sap at all anyways. I did a recirculation wash with it and after 4 hours the temp didn't rise at all. I may have to install a heater, but that a different topic.

One guy told me you shouldn't think of it as making the concentrate as quickly as possible, but making the most permeate possible(water that you don't have to boil).

Any thoughts out there?

[tuckermtn]

I am guessing the Sap Brother does not have a recirculation pump? So the typical increase in sugar percentage would be doubling. If that is the case, I would dump back in to the original feed tank and be continually sweeting and then when you are ready to boil, do the final pass and dump to evaporator feed tank. I would not worry about boiling different percentages of sap during the same boil.

[TunbridgeDave]

It doesn't have a recirc. pump but it does have a valve that effectively does the same thing by letting the concentrate flow back to hp pump inlet. It does have a concentrate valve so you can adjust how much water you take out. The original brochure from the 80's gives flow rates at different concentration levels and they really drop off when you get to 75% water removal. The rig is designed for low pressure (200-250 psi) also.

[Brent]

I've been trying to find some specs on your rig and came up blank. What is the motor power on the pump(s) ?
What are the membranes ....size and make ?

[TunbridgeDave]

Yeah Brent, there's not much out there. When Small Bros burned to the ground back in the early 90's everything was lost. The rig was made by Osmonics out of MN. I think the company is part of GE now. The original Osmonics membranes were quite poor, I think they were the hydranautic type where you could use bleach to clean them, the brochure said they could even be frozen. The feed rates according to the original brochure were 70,52,46gph at 50,67,75% water removal. The feed pump is just a Jaccuzi 1/2 hp 7.8 amp pool pump, and the hp pump is a Procon 240gph with a 3/4hp 11.5 amp motor. The max system pressure I was able to get on it was about 225psi. It has all plastic nylon tubing and fittings so that's probably about all I should expect. I did a test making permeate out of well water and got 200gph using 2 new XLE 4040 membranes. There is a recirc valve on it that feeds the concentrate back to the hp pump but I don't know how much to open it during concentration. Other than that there is not much to tell. It's a pretty basic machine, no heater, no wash tank, etc.

This is going to be a big learning experience for me being my first RO in 30+ years of sugaring. But I couldn't beat the price............free!

[Brent]

Dave You've already made the best move by going to the XLE-4040s.

I think your evaporator is going to go through sap a lot faster than your RO so my tendancy would be to go with the simple method. I ran the XLE's last season and they are the best for your low pressure. In the 1st 20 minutes of a sap run you will see a significant drop in GPH of perm, maybe 20%, but then they stabilize and go for hours with only a very slow change in performance. We ran just under 600 taps with about 2 - 2-1/4 coming in and about 7 - 8 going out and the RO could barely keep up with our 2-1/2x8 with the steamaway. If we put on another 50 or so taps, (that I will be working on later today) we'll hit the wall half way through the boil each day. I don't know how you collect back to the sugar shack, but that will affect when you can start the RO and if you can keep it feed for a couple of hours before you lite the fire. If we started the RO 2 hours before we lit the fire ( really doing about 180 GPH at 7-8% after things stabilized ) we were sometimes openning up the flows by the end of the day just to keep feed going to the evaporator.
We had a 275 gallon tote for concentrate and never needed more than that. Your output will be lower, especially keep in mind that the test you did was on well water, and you'll lose about 20% on sap after the first half hour or so.
I don't think you'll need more storage than us ... but that depends on your style ... you may prefer to hold off liting the fire longer than us.

Our RO maxes out at 300 PSI 1 Hp / 3 Hp pumps. I tried running it a bit more open at lower pressure and could not see any measurable difference in the rate that membranes fouled. So I'd run it at max pressure and regulate it from there to match your boil rate. You will find you're a bit busier at the draw off end of the process. You'll be going through pre-filters and pails a little faster. It will feel good until you hit the chinese fire drill point of too many things happening simultaneously ( start a wash cycle on the RO, feed the fire, change the filter, find more buckets, change the valves on the RO for the wash, OMG need and other pre-filter and bucket, OH NO need to go to the little boys room for #2, etc etc.)

[Brent]

PS
priming pumps for the RO on our set up was a bit of a bitch. Make sure your feed tank to the RO is higher
than the feed pump. Have a valve inside the sugar shack so you can stop the flow into the RO when you want to clean the strainer and change the filter. I am going to have a Banjo 3 way valve inside this year so I can select the source, either sap or perm for cleaning, without going outside and fiddling with connections etc. The Banjo 3 way cannot be shut off so it needs a separate shut off. Similarly, I'm going to have 3 way banjos on the perm and concentrate outlets so I can just switch them to dump to waste or dump to the concentrate tank and perm holding tank. Did too many chinese fire drills with all that last year. And all that switching came near midnight when things were getting fuzzy upstairs.

You'll have fun.

[danno]

Dave -

Glad you figured out your wiring issue - what was it?

Couple threads last year on the issues you raised. The concensus was dump your sap back into your original holding tank if you want to re-circ. This will keep your concentrate cooler and at a lower concentrate level (because it's mixing with raw sap) and will thus keep your sap fresher. I run my re-circ line back into my bulk tank as far away from the outlet line on the tank and releaser for the same reason.

I think whether you re-circ depends on several variables - RO concentrate output as compared to evap gph, how long you want to boil and how much fuel you want to use, amount of sap collected, % of raw sap. I was defintely re-circing when my sap was down to 1.25% raw and only 4% after first pass.

Regarding heating your wash solution, this is what I used last year. Worked great!

http://www.tractorsupply.com/allied-precision-bucket-heater-1000-w-2170534#BVRRWidgetID

I do need to figure a thermostat to work with it, because this heating element will bring your water too hot if not monitored and shut off timely.

[danno]

And Dave, if your Sap Bros is set up the same way as mine - you will have a 3 way valve where you can send your concentrate to your sap tank or wash tank. Same with permeate line - with a seperate 3 way, you can send it to your permeate tank or wash tank. We always push some permeate through the membranes to push the left over sugar into the sap tank before we begin a wash cycle.

NOW THE IMPORTANT PART - when you open your wash tank valve to push your wash solution into the membranes, make sure you change those 3 way valves, directing the solution to the wash tank, and not into your sap tank! Been there, done that. No fun dumping a few hundred gallons of concentrate. Late night when you're tired, it's an easy thing to forget to do. I now have a big sign taped on the face of the RO reminding me to turn those valves.

[TunbridgeDave]

I knew I could count on you guys Brent, Danno. Thanks for the input.

Danno, I had an electrician here for about 4 hours trying to figure out the wiring on this thing and he gave up and just re-wired it. We took out the programmable timing relay and that made things much easier. So now you just have to hold the feed button in for about 2-3 sec until the pressure builds and then release and start the hp pump.

All but about 80 taps run right to the 400 gal bulk tank at the sugarhouse so we don't spend much time gathering. We have a 350 gal feed tank for the arch and 2 horizontal plastic tanks, a 325gal I was going to set up as the perm tank and a 125gal for gathering. On the days it runs well we may not be able to recirc into the bulk tank for very long. Sometimes it's full after about 4 hours. It will seem good to be a little busier on the draw-off end of things Brent! We finish right on the rig and when you draw only about 1 to 1.5 gallons every half hour or so, the filter press barely stays hot enough to filter effectively. I keep a blanket over it and have to use the bypass valve on it until the cold syrup in the pipes gets re-heated.

I'm sure it's going to be a learning experience. I plan on buying a bunch of 3 way valves and drains, and I like the heater you showed me Danno!

[danno]

OK with the heater, you have to find a thermostat to control it and let me know:) I was thinking a hot water heater thermo or maybe a fish tank heater.

[Parker]

I have a sap bros r.o.(your vintage) that is all set up and I ran a bit last year,,,it is plumbed really well for washing, re circulating-onepassing-lots of options with tanks..come up and take a look if you want...works really well...

[TunbridgeDave]

Thanks Parker for the invite, I may do that. Do you have a manual for your machine? I've been trying to research this valve on mine that I believe is for recirculating the concentrate through the membranes. There is a ball valve and a needle valve that allow some concentrate back into the hp pump inlet, but I don't know how much to open it during concentration. I included a pic where valves are labeled F and G.

I've had others tell me they don't have this setup on their Sap Brother RO, so maybe it's not original.4914

[Brent]

what I don't see is a built in 5 micron filter. I hope there is one off the frame.

[Parker]

I was looking at my r.o. yesterday and I do have that valve on mine..I left it closed last year while running because I was not sure what it did...I will try playing with it this year.

[TunbridgeDave]

Yes Brent, there is a filter just out of the picture on the left side of the machine. I actually moved it inside the machine as I plan to insulate the whole thing. That way I don't have to build a room for it. A light bulb should be enough to keep it warm on cold snaps during the season and I removed the canisters for Winter storage.

Parker, do you have the same size/type membranes and pumps as mine?

[Parker]

Mine seems a bit larger, originaly it had 14 4" membranes in 7 vessells,,it has a tonkaflow pump powered by a 7 h.p moter,,I now have 6 4" membranes in 3 vessels..thinking about adding 4 more membranes..I am running xle-4040 membranes...I found the instruction manual...not much to it....that valve is used in the washing cleaning cycle. pm me your adress and Ill mail you a copy...Parker

[twobears1224]

i,ve been studying this picture..is the part lettered G a drain?? it sure looks like a drain petcock..kinda like whats on a radiator.

[TunbridgeDave]

Actually Twobears, it's a needle valve. This is the only part of the machine I haven't figured out yet and I'm getting conflicting ideas as to what it's for. My guess is that you set the flow rate with that needle valve to recirculate the sap through the membranes while concentrating. Then you just use the ball valve (F)to switch back and forth from conc/wash,rinse. I'm anxious to fire it up this spring!