CDL 600 RO question

[mainebackswoodssyrup]

Question for the guys out there who run a CDL 600 RO with lower side tap counts/sap runs….
How much sap do you need in each run to generate enough permeate to rinse and soap wash these RO’s? 600 gallons?
Our average sap run when we get full vacuum should be at least 500-700 gallons with peak runs probably 1,000 or more. It’s the early/small runs I worry about. I am trying to find a way to get 10-12% in one pass instead of 6-8% with a hobby RO. We would squeeze the 600 as hard as we can. I’d prefer not to recirculate with a hobby RO although I realize that probably fits our operation better. I know Lapierre has the turbo 250’s that might do it but I really am cautious of the local support from CDL that is 25 minutes away.
We have planned for an 800 gallon permeate tank, originally expecting to run a 250 RO but we also have a 1200 gallon tank we could use.

[ecp]

You should have 600 gallons on permeate to rise/wash/rise a single 8-inch membrane (CDL 600). Albeit you can get away with less, but always try to get 300 gallons through it for de-sugaring before a wash. the post rinse is to get the soap out so that one you can short a little.

[VTnewguy]

I'd use the 1200 tank and save some permeate for when you need it.

[mainebackswoodssyrup]

Thanks for the numbers, that’s what I figured. I’d be short on a 500 gallon run but close on a 700. What’s the ratio of permeate/concentrate you’re getting if squeezing it up to 425-450 psi?

[mainebackswoodssyrup]

I'd use the 1200 tank and save some permeate for when you need it.

Ya I think we will go with the 1200. Plan is to keep one and sell the other depending on how we set it up.

[ecp]

Thanks for the numbers, that’s what I figured. I’d be short on a 500 gallon run but close on a 700. What’s the ratio of permeate/concentrate you’re getting if squeezing it up to 425-450 psi?

You would be better off double passing with a single post unit and keeping your pressure sub 400 psi. Smallest RO I've had was a 2 post, and that had issues getting to 12% in 1 pass at any decent rate (especially with cold sap). If you have small runs there is nothing wrong with doing a concentration cycle and just a rinse after it with what you have for water for a single 8 inch post a 400 to 500 gallon run really isn't pushing it so a wash cycle could wait until the next run. At the end of the season that can be an issue but at the beginning it will be fine. I've done it plenty of times.

[Amber Gold]

I agree with ECP. Double pass it to get above 8%. It's what I do. My method is the conc. stays at 2gpm, pressure at 350psi, and the perm flow is what it is...generally 5.5-6.5 depending on sap temp. On the second pass, same settings, but the perm flow is 2-3gpm.

Use a 500 gal tank for a concentrate tank and the 1200 gal tank for perm.

Like others said, 600 gal of perm. is the minimum recommended if doing a soap wash. I do a soap wash every time, just so I don't have to worry about it if I get a big run. Also, I think if double passing, you're getting more buildup, so it's good practice.

[mainebackswoodssyrup]

Thanks for all the info, I appreciate any opinions or ideas to consider. My concerns with recirculating were:
-Will extra buildup on the membrane be too much for just doing a rinse. And how long can the membrane sit with only a good rinse? Sometimes runs early on follow with a 1 or even 2+ week freeze between collecting/boiling. Middle to end of season we seem to collect boil every 3-4 days and I hate thought of letting sap sit longer just to have enough to run the RO.
-Will recirculating make darker syrup as it heats up the sap a second time or will this machine process the small quantity fast enough that it shouldn’t make a difference?
-Should I have or do I need another tank for recirculating? How would I know when to stop if just using one tank?
-I was planning to try and save permeate for storage in the tank but it will be above the ro room and in an uninsulated part of the shack. I’d be worried it would freeze. With a small RO I could just wash then rinse until all the permeate was gone because I wouldn’t have to save any.

A smaller RO would eliminate some of these concerns but I just like the idea of being oversized if possible. No plans for more than 700 taps due to available trees but you never know. And I know the cost significance is different but I just think the bigger RO’s are built better.

[Amber Gold]

We used to recirculate for years, and it takes longer. We had a sap tank and a perm tank. We'd recirc back into the sap tank until the sugar content was where we wanted it, and then we'd send it to the head tank. I believe you do make darker syrup recirc'ing.

I think it was 3 years ago, we stopped recirc., changed the perm. tank to a conc. tank, and bought a 1550 gal perm. tank. This system works much better and gives us more flexibility. I wouldn't go back.

[Brian]

If that is all the sap that you have, I would wash every other run and just rinse the 600 ro every other, and yes I would eather recirculate the sap or run it through twice. That will give you enough permeate to do whatyou need. I run a 600 ro for 3 years on 4000 taps so you should be fine. that machine can handle some sap. I didn't get much sleep back then.

[mainebackswoodssyrup]

Can it sit for more than a few days without a soap wash?

[ecp]

Can it sit for more than a few days without a soap wash?

Yes, because the "quick rinse" pushes all the sugar out of the membrane. All that will be sitting in the machine in permeate which will be fine. Most guys around me are letting permeate sit in the machine all year. I don't know much about recirculating but if i was to do it i would recirculate into the same tank until the tank got to x% sugar then send it to the head tank. I'm sure like anything once you get in a rhythm it will be easy.

[ecp]

I run a 600 ro for 3 years on 4000 taps so you should be fine. that machine can handle some sap. I didn't get much sleep back then. I would guess you wouldn't be getting much sleep on those numbers. I too was guilty of an undersized RO for about 5 years (well longer than that but when we were only looking for 8% back in the day it kept up).

[mainebackswoodssyrup]

Cool, thanks guys. I'm going to size tanks and everything for the 600 and make a decision when the time comes. Who knows, maybe 8% is all I will want to run in the 2x6 but recirculating would help get more permeate. I'd rather not add another tank so would try just using the same one. And yes- it will be fine once I get a rhythm, just want to set everything up right the first time. We will be putting high vac on our 230 tap line for next season which is now gravity so that will tell me how much sap we will really be dealing with. Going to buy a small hobby RO on a dolly to get thru the next 2 seasons until the new shack is complete.

[Brian]

Thats right, 8% was great, then more was better. and that was what I was doing. yes you can let it sit after a good rinsefor a day or two.

[SeanD]

I agree with ECP. Double pass it to get above 8%. It's what I do. My method is the conc. stays at 2gpm, pressure at 350psi, and the perm flow is what it is...generally 5.5-6.5 depending on sap temp. On the second pass, same settings, but the perm flow is 2-3gpm.

Use a 500 gal tank for a concentrate tank and the 1200 gal tank for perm.

Like others said, 600 gal of perm. is the minimum recommended if doing a soap wash. I do a soap wash every time, just so I don't have to worry about it if I get a big run. Also, I think if double passing, you're getting more buildup, so it's good practice.

Excellent questions Maine...syrup. Very helpful for expansion planning/dreaming - and great answers provided.

Amber Gold, thanks for sharing those rates. Based on those numbers, you are removing about 75% in the first pass then 50% in the second pass? Do I have that right? I'm trying to plan how far/big I can go if I upgrade my 250 RO to a 600, but stay with a 2x6 on the boiling side.

[Amber Gold]

Yes, that is about correct. However, with this season's amazingly low raw sap SSC, I had to recirculate the concentrate to get the sugar content up to ~15% before I started boiling it. When you're starting at 1%, you can't get to 8% on the first pass.

[SeanD]

Thanks. That's a big help. Generally, I target volumes and rates when boil to see how long I'll be at it that night. The percent is just a bonus, except for this year where all bets were off. I told myself to stop checking the raw sap sugar content for the rest of the season, but it was like a car wreck. I couldn't help but look. Historic lows. It can only get better next year.

I'm looking at your tap counts in your signature. When did you make the jump to the 600 RO and the 2.5'x8'? I'm guessing 2012 or 2013.

[mainebackswoodssyrup]

Funny this thread just popped back up. I found myself a CDL Turbo 250 RO that I picked up in NY this past weekend. The machine is the 600 cabinet with the 3 HP turbo and a 1 HP feed pump, 2012 model. It has 2- 4" towers with 1/3HP recirc motors. Didn't even realize CDL made these for a period of time. I spoke with CDL about it and they confirmed they did in fact make 4" towers around 10 years ago for a period of time. Recirc motor parts would be my only concern but they still have them and can get parts or new motors from Grainger. So, I'm pretty excited to have the machine. Turbo power, high PSI, won't have to worry about permeate for cleaning and I can stay with CDL for the local parts support. I was very close to getting a Lapierre Turbo 250.
We have the tanks already which are sized for a 600 and are doing the slab for the new shack this summer. Now if I decide I want to upgrade to a 8" post, I can have the wiring changed and run 1 post with this machine. Might be more like a 500 then 600 but no issue running 1-8" post which is all we will ever need. Planning to send the machine to CDL for a full service before we use it, maybe I will have them add the 8" post wiring then so it's there if I want it down the road.
So now I have the 600 for sale.

[SeanD]

Congrats on the new purchase. It's nice to have the flexibility you were looking for. I don't sweat the early season small runs as much because it's typically still really cold and the sap will keep as more comes in the next day. It's the end-of-the-season runs that are tough for me. The sap won't keep and the permeate is dwindling. You should be good.

Are the Turbos units set up with larger pumps designed for a 8" membrane pushing through two 4" membranes at a higher pressure? I hadn't heard of those. Aside from changing your math on the permeate, what are the rates like on a Turbo 250?

I was talking to Ray Gingerich at Deer Run recently and he makes a 500 GPH with a single 8" membrane for a VERY reasonable price. It will take 2% to 8%. Each unit is built to order, but he works quickly. If I'm able to make a big jump in tap count, that would be a unit I would consider. He doesn't advertise, so I thought I'd put that out there.

[mainebackswoodssyrup]

I wish I could post a picture on here! Send me an email address and I'll send a picture if interested. Don't see many of these units, really a rare find. It is the same turbo setup as the 5 HP or 7.5 HP or any of them. The machine itself looks exactly the same. The wiring in the cabinet now is for 2-4" posts but put the right relay in and you could run 1-8" post or more. I would have to swap out the turbo to a 5 HP to run more than 1-8" post but this setup as is will run 1-8" post or the 2-4" posts which is all I should ever need. It's a similar machine as to what N8hutch has, but with 4" posts. It's an expandable cabinet so I could put a 7.5 HP pump and run 3 posts if I had enough sap :lol: That's what I really like about it, the expandable/flexibility and ability to get sap in the teens if I want to do a second pass. Previous owner said he would get 10% on one pass with the 4" posts at 425-450 (max) PSI. I'll play with it to see what I want to do. Nothing wrong with Ray's machines, especially at their price point.