MORE RO Questions.

[ibby458]

I've read as many of the old posts as my ultra slow dial up connection will allow, but still have questions.

I'm planning for 1000 taps on vacuum next year. That's maybe 2000 gallons of sap/day. My rig will go thru 75-100 gph with good wood, and I really can't boil over 8 hrs/day. Obviously, this equation doesn't work.

I've rejected a bigger unit (too much wood to handle) and a Steamaway. (Too much money for a unit that can't be used on a different size evaporator.) That leaves RO as about the only choice.

I prefer to pick up the sap in the evening, let it sit in the bulk tanks overnight, (circulating thru a filter and UV light) and boil it the next morning. Will a RO operate untended all night? That would let me concentrate all night.

How much power does a RO require? With some of the highest electric rates in the country, that's a factor to be considered as well.

Is there any book that details what must be done, and equipment required for RO operation?

Thanks!

[michiganfarmer]

How much power does a RO require? With some of the highest electric rates in the country, that's a factor to be considered as well.

Is there any book that details what must be done, and equipment required for RO operation?

Thanks!

I have been talking to a supplier abut buying an ro. The newer ones are practically hands off. You can fill your sap tank, turn them on, and go to bed.
BUT, they are pricey. The 250 gph I was talkiing to him about is $12,000.
It takes 220 volt, and draws 26 amps.

I asked if I need to buy pre filters or if the machine comes ready to use. He said it comes ready to use except I need to buy the correct size fittings to fit whatever tanks I have, and the washing sulitions have to be purchased seperately.

[maplwrks]

IBBY-- You'll need a 600 gph unit. You would be able to process and boil at the same time. You should be able to pick up a new Lapierre for $12000 during the spring sale. You will need to plumb it up to your tanks. 40 amps are required to run it. That rig will process that 2000 gallons in just over 3 hours. If you were to start the evaporator and RO at the same time, you would be able to shut down when your RO shuts off. I have the same size rig as you and I am able to concentrate this way.

[ibby458]

Ouch! That's a couple kicks in the gut. 40 amps at 14 cents/kw is a BIG power bill. Not to mention the purchase price. I was hoping to find an older used unit that would run overnight by itself.

Since I haven't formulated plan B yet, that leaves plan C. Boil what I can and sell the rest as sap.

[Jeff E]

Ibby, if you find a smaller capacity RO and you do run it overnight, it may work if the unit is dependable. Personally I would have a hard time not checking on it often. (meaning poor sleep)

If you have 1500 gallons of sap, and a 125 gph RO, the reality is it will average about 80 to 100 GPH. If you recirculate the sap, and the RO is 75% efficient at removing pure water, the permiate, it will remove 75 gallons per hour.

Sleep 8 hours, remove 600 gallons. Then direct your concentrate to your feed tank instead of your bulk tanks. Get the fire going and adjust your flow rates to keep up with the evaporator, if possible. I would think you could set a 125 gph unit to let out concentrate at 1.5 gpm. It will probably reduce the units efficiency, but you should still be boiling 8 to 10% sap.

[Brent]

Let see how expensive that really is

40 amps x 220 Volts is 8800 watts or 8.8 Kw

8.8 Kilowatts x 14 cents is $ 1.23 per hour ( 14 cents per KW hour )

On an average day you might run 4 hours. About $ 5 bucks a day.

Don't know what you're using for fuel but you can't even cut, split dry and haul your own wood for 5 bucks a day.

Go back to the boil rate of your evaporator and get a unit that will match your boil rate with concentrate. Come home, start the RO, have dinner. The RO will have a feed tank ready for you, and keep up with you for the rest of the evening. Go to bed at a decent hour.

If you go to vacuum next year, those number will change.

That's the way I see it with my limited experience anyway

[sapman]

They recommend rinsing my membrane every 4 hours, and I think all manufacturers say that, don't they? I know mine will slow way down, especially with late run sap, or when concentrating pretty high. I, too, would recommend a 600 gph unit for your size, if there's any way you can swing it.

Tim

[PerryW]

I guess I still don't understand the math...

If Ibby gets 2000 gallons of sap per day and it sits in his bulk tank overnight (12 hours); then ... WHy can't he get something like a 100 GPH unit?

In the 12 hours he is sleeping, 1,200 gallons of sap will be processed. Then while he is boiling, the R.O. will continue to process the additional 800 gallons?

Also, his wiring would be much simpler with a smaller system (not having to install 40 AMP 220 circuits in the sugarhouse)

[brookledge]

The problem I see with that is you would need to get up in the middle of the night and do a rinse cycle and then go back to bed. I would think that would lead to poor sleep. I know what you are saying but if the membranes need to be run through a rinse cycle after 4 hrs or so it sort of defeats the purpose.
Keith

[sapman]

Give Theron a shout. I think he did that this season.

Tim

[Brent]

Yeh and if you've seen the ad section Theron is looking for a bigger RO.

There is a lot to be said for "right sizing"

[PATheron]

Guys- Running it through the night works real good. Thing is, like Keith says, you do need to get up and rinse it in four hours which I do. I assume you would with any of them regardless of size. It only takes maybe five minutes to rinse it though. The 600 is a nice match to my 3 by 10 evaperator. The problem for me is Im trying to run taps that kind of command a bigger evaperator too. Other thing is Im limited on time becouse having to go to work. I would get the 600 becouse I think personally that you should get the biggest R.O. you can afford becouse they often dont operate at the max rating plus you always want to do more taps. I also dont think the electric bill is a big issue either becouse if he recirculates the sap during the night he'll run it up to a fairly high concentration and save a ton of money on evaperator fuel, etc. If he can afford the 600 I think it is the way to go. Theron

[ibby458]

Thanks for pointing out the facts and helping straighten out my thinking.

My new sugarhouse is still in the planning stage and putting in a 100 amp sub panel is just as easy and hardly more expensive that a smaller one. I might not need 100 amps, but if I do, it's there.

My current thinking is a 200 gph model. I'll haul the sap home in the late afternoon, start concentrating at 6pm, and do a rinse cycle at 10pm, then go to bed. I'll put a timer on the unit to shut it down when it needs another rinse. I usually get up around 5 am, and I could do the rinse then, and go get breakfast, etc and start boiling at 8 or 9am.

That'll give me 12 hours total concentrating time X 200 gph = 2400 gpd. Should work MOST days. On those inevitable days when things go wrong or there's a BIG sap run, I can get the boys to boil all evening if needed.

Suppose I get 2000 gallons of sap at 2.5%. (Not unlikely in this bush). If I just concentrate it to 8%, that'll cut it down to around 650 gallons. (if I did the math right - please correct me if I'm wrong!) I can boil that in 8 hours easily.

[Thompson's Tree Farm]

Ibby, The longer your RO is shut down before you rinse, the harder it will be to get it rinsed clean. Also remember that a 200 gph machine will seldom do a full 200 gph especially toward the end of the 4 hours. Check with Russ Lampron on here about his 250 and what he gets through his and how he does it. He is very savvy about RO's.

[ibby458]

Unfortunately, money is an issue. If I can afford any RO at all, it's gonna have to be a smaller used unit, and hope to trade up later.

I may just put a cot in the sugarhouse and sleep there. I gotta pee several times during the night, so getting up won't be a problem. I am DEFINATELY putting a bathroom in the sugarhouse. (You ever get ALMOST to a draw, but just can't wait, gotta run to the house NOW?)

[Brent]

Question for Theeeeeeeron

I was under the impression, being a new Airablo owner, that the rinsing was supposed to be a flush with permeate approx equal to the units hourly capacity. Mine is a 180 GPH and although I have never done a flush, my impression is that it will take a lot more than 5 minutes to put 180 gallons through it.

[Russell Lampron]

Brent a flush is when you use permeate to get the sugar out of the membrane with the RO concentrating. It only takes about 5 minutes. A rinse is when you run all of the permeate through it in the wash mode. If I am doing a flush and plan to continue concentrating I will change everything over to wash mode after the flush and run about 50 to 100 gallons of permeate through then switch back to concentrate mode and continue concentrating.

[Brent]

Russ

So when I'm planning the plumbing I would want to be able to switch tanks from the sap to the permeate and restart. Do you switch the concentrate line to dump it after maybe a minute, or just keep it going to the evap feed tank, even though it will be a bit dilted?

[markcasper]

I leave my concentrate valve open to the feed tank while flushing for about 10-15 minutes. It takes a good 10 to get the concentrate to under 1%. When the permeate starts trickiling into the wash tank, the membrane is usually close to being desugared, below .3%.

[Russell Lampron]

Brent I let the concentrate go into the head tank or back to the bulk tank while I am flushing. The little bit of dilution doesn't have much of an effect on the concentration level in the tank. It would be wasting a lot of potential syrup to run it down the drain.

I have valves for the sap storage tank and permeate tank at a tee close to the RO machine so that I can switch them from one to the other and back again. When I don't switch it over to wash mode I don't even turn off the RO. I just open one valve then close the other and keep on going.

I do the same when I am recirculating and boiling. I run just enough sap into the head tank to keep ahead of the evaporator and switch back to the bulk storage tank. My RO room is a mass of valves and pipes.

[Jeff E]

Just started reading this...

Russ, when you flush, it sounds like all you do is change your input from sap to permeate. Run it like that for 5 minutes, and switch your input back to sap.
Correct?

The CDL front panel basically has me running through the initial steps of a wash, which involves opening flow valves up for more circulation, doing a concentrate recovery for 5 minutes then dumping the permeate output down the drain.

Thoughts on the CDL way?

[Russell Lampron]

Jeff that is all I do when I do a flush. I send the concentrate back to the bulk tank or up to the feed tank depending on where I need it at the time. The permeate goes back to the permeate tank. When I am flushing it all I am doing is getting the sugar out of the membrane to freshen it up a little or cleaning it out before I do a wash. It only takes me about 5 minutes to do this because I run my concentrate flow near the max that my RO will put out. If I slowed the concentrate flow down it would take longer like it does for Mark Casper.

I'm not sure what CDL is having you do and I don't see where what I am doing wouldn't work the same way for you.

[markcasper]

I think what Jeff is trying to say, and he can correct me if I'm wrong.....is that we only use the feed pump to feed permeate back to the RO. When the machine runs out of sap and shuts off, we open the concentrate valve and pressure valve wide open, open permeate supply and push the feed pump start button. We keep the concentrate valve turned on to the tank and turn the permeate valve on to the wash tank. At least for me.....nothing comes out of the permeate side of the membrane for at least 10 minutes. When the permeate line starts piddling into the wash tank, I check the sugar% and is usually 1% or lower. When it gets down to .2 or so, I turn the concentrate flow valve to the wash tank and let it rinse for 20-30 minutes down the drain.


I never run the high pressure pump while doing a rinse or wash.

Russ you are probably right, most of the time I am concentrating sap thats already been concentrated, thus theres more sugar on the membrane to flush out and takes a little bit longer.

[tyrod2]

How much psi. should you use to run permeate back into the RO.?