RO and tanks

[mainebackswoodssyrup]

We’re hoping to get a small RO in the next couple of years. One issue is the room we have for tanks. Does anyone RO from their raw sap tank right back into it? And just check the sugar content as it runs to decide when to stop? Longer term plan is for a new shack which will be set up for it but would like a RO before we can do that.

[mol1jb]

That would work. You just have to remember that you want to clean out any tank that holds concentrate frequently, ideally after every concentration cycle.

[maple flats]

You also need to realize that when you concentrate sap, you also concentrate the micro-organisms. Thus concentrate does not keep well unless it is kept cold. Going to 3 or even 4% might not be an issue unless the concentrate is maybe above 38 F, if going to 7 or 8% you either need to boil now or cool it to 30-32 F. The higher the concentration the sooner you must boil it or the colder you must store it at. Running it thru the RO raises the temperature too, but a low pressure RO will not raise it as much per pass as a higher pressure RO.

[1arch]

We’re hoping to get a small RO in the next couple of years. One issue is the room we have for tanks. Does anyone RO from their raw sap tank right back into it? And just check the sugar content as it runs to decide when to stop? Longer term plan is for a new shack which will be set up for it but would like a RO before we can do that.

I recirculate back into my 600 gallon holding tank until I reach about 13% then I switch the concentrate flow to my head tank. As mentioned cleaning with permeate and a brush is a must.

[mainebackswoodssyrup]

Thanks for the information. The tank is accessible and easy to clean. We have hot water at the shack too. A big run for us is 500-600 gallons so the plan would be to ro and boil right after. Some runs may only be a couple hundred gallons. We would have a permeate tank or tote in the loft of the shack for rinsing/washing.

[johnallin]

We’re hoping to get a small RO in the next couple of years. One issue is the room we have for tanks. Does anyone RO from their raw sap tank right back into it? And just check the sugar content as it runs to decide when to stop? ... .

With high vacuum this year and an electric releaser pumping into the sap tank I needed a way to better process what I was bringing in.

Sugar was low here this year, so I purchased a CDL Hobby 100 RO and I did just that. It's portable enough to position between my sap and permeate tanks. It will process about 50 gph each of concentrate and permeate.
It's a basic machine with no low pressure shut-off; so I set it up on a timer. If I've got 300 gals of sap I let it run for 5 hours and go to work. I then pump that tank up to my head tank in the sugar house with a new SS Gould pump purchased just for that purpose.

Next year I will play with running pipe through the wall to the tanks, keeping the RO inside. I'm very happy with what the little CDL 100 did this year and would recommend it to anyone looking at a first time unit without breaking the bank$$.
RO march 2019.jpg

[mainebackswoodssyrup]

I have some research to do on the RO part. I’m thinking a used 250 size RO but not sure yet. CDL and H2O are the nearest support and most of my sugaring friends have CDL just because they are closest and have parts on hand. I wish they made a full featured 150-250 size with a high pressure pump like Lapierre does. Maybe they do, haven’t looked too much into it.

[GeneralStark]

Does anyone RO from their raw sap tank right back into it? And just check the sugar content as it runs to decide when to stop?

Yes this works and many do it.... but it is not the most efficient way to run an ro. The sugar settles to the bottom of the tank and essentially reduces the machine's ability to remove water, which is the primary goal of the ro. At your scale this may be ok, but if you want to be as efficient as possible you may want to consider having a tank to concentrate into, and then pass again to your head tank.

A floating tank inlet is also an option so the ro is being fed with sap from the top of the tank. It is tough to get an accurate sense of the sugar concentration in a tank when you are recirculating. Testing the concentrate leaving the machine works, but is still not so accurate.

It really all depends upon how quickly you want to process your sap and what sugar concentration you are hoping to boil.

[wiam]

Yes this works and many do it.... but it is not the most efficient way to run an ro. The sugar settles to the bottom of the tank and essentially reduces the machine's ability to remove water, which is the primary goal of the ro. At your scale this may be ok, but if you want to be as efficient as possible you may want to consider having a tank to concentrate into, and then pass again to your head tank.

A floating tank inlet is also an option so the ro is being fed with sap from the top of the tank. It is tough to get an accurate sense of the sugar concentration in a tank when you are recirculating. Testing the concentrate leaving the machine works, but is still not so accurate.

It really all depends upon how quickly you want to process your sap and what sugar concentration you are hoping to boil.

Another way to do this is a stand pipe that is removable. I had a piece of pipe that fit snug in the bottom outlet that had holes cut at about 1/2 the tank height. This would draw sap from higher in tank and shut the ro down when it got down to half full. Then I would pull pipe out and start sending to head tank. Another tank to do first pass and then second works better. But we all have to start somewhere.

[Russell Lampron]

I used to recirc into my raw sap tank which like others have said is very inefficient. If you don't have room for a dedicated concentrate tank you can certainly do that.

I do think that CDL has professional 125 and 250 RO's like Lapierre does. Don't to be afraid to buy a used Lapierre. You won't need replacement parts very often and Lapierre USA in Swanton VT has excellent customer service if you should have a problem. Because of people upgrading there are a lot of good used 250's out there. I recommend that you get a professional model 250. It's pairs up well with a 2x6 and is able to concentrate at higher levels and at higher pressures than the hobby RO's. I added a second tower to my 125 Lapierre Turbo to make it a 250 and it's something that I wish that I had done years ago. I've had my Lapierre Turbo since 2005 and have only had two problems in that time. The high pressure control valve which was made of brass cracked and I had a bearing failure on the recirc pump motor. I was able to make both of the repairs myself. Lapierre started using a stainless high pressure control valve shortly after my RO was built in 2002 so that won't be a problem on a newer RO and the pump motor bearings can be sourced locally or online. When I replaced the bearings in my pump motor I also put new seals in the pump which Lapierre USA had in stock.