RO operation

[maple flats]

Am I running my RO correctly? I boil about 65 gph and I run my RO by running raw sap and setting the RO to keep even with the evaporation rate. This runs my 250 RO at about 250 gph and gives me 7% concentrate. If I run the pressure up I don't match the boil rate. Would I be better not starting the evaporator until I have more concentrate at maybe 8 or 10% in either 1 or more likely 2 passes or am I doing right with a 250 and matching rate to the boil with only about 25 gal concentrate reserve in the head tank? It seems easy and convenient but am I losing out on potential?
Dave

[maplwrks]

Dave-- I would think that you should be very pleased with the results! I concentrate very high, but thats my choice. I think if you are comfortable with the boil and the speed of syrup being made, you should stay with it. It's up to you. If you wanted to see what higher concentrate would do for you, you could squeeze it down a little and give the RO a headstart before you boil.

[maple flats]

Squeezing it down more has very limited potential on my RO, for the 7% I am near max pressure. It is possible to get 8% in 1 pass, for higher mine requires 2 passes.
I am pleased with the results, my question is merely to try to educate myself on tweaking the performance.
My RO has a max pressure of 300 PSI and the way I am running it I'm at 275-280. Adjusting to 295 drops flow from 1.2 gpm to .4-.5 gpm. My thought was that mine is really only made to take 2% sap to 7% in one pass.
How many double pass their's?

[firetech]

Dave I'm no expert in this but Wed nite I ran my Ray G unit for the 1st time. I was very busy with the refractory meter. Here's what I saw. 500 gals of raw sap, just lite of 2%, first pass took it to 6% after 2 hrs of total run time recirculating it back into the tank I boiled 150-170 gals 11-12% sap never letting the PSI get above 250#. My evap burns 50-55gals/hr the RO is a 375gph. I have never spent this much time at the draw off valve. I was all cooked,cleaned up and in the house before midnite started at 6:30pm. This was a 10 run, plus clean up last year. Good luck Today I have 1200 gals to play with.

[sugarman3]

Ihave started doing 2-3 passes this year,gotten sugar content up to 14.8 before it goes to the tank that feeds the evaporator,still playing with what is comfortable to run the evaporator with.We made 22 gal wed in 2.5 hrs boiling-10% sugar-33 gal thurs night in 2.5 hrs-12% sugar.Iusually run the last 400 gallons of sap at about 7% to lower the sugar in feed tank just as we start to boil.My ro is 500 springtech and running it through at50% the pressure on the ro runs about 250-275.Next run i am going to go a little higher,made 100 gals of all very light

[Brent]

it's a bit of a conundrum isn't it

If you concentrate more, your evaporator has even less water to remove so the ability of the RO to keep up with the evaporator
gets worse. We're already in that zone because of, in no small part, the Steamaway. With the new XLE membranes we run about 180 GPH and get 80-100 G or 7-8%. We dump the concentate into a 275 G caged tote. We start the RO about 2 hours before we light the fire and on an avarage day, the RO runs out of raw sap about 1/2 hour before we shut down the evap. Just enough time to run the wash cycle. I wish the RO had about 25% more capacity.

[maplwrks]

All very good advice!

[sapman]

I think one thing to consider is how light you want your syrup, at least in my case. My machine is too small now, so I'm recircing for 10 hours+ sometimes, which seems ridiculous. But the sap is only about 1.5% this year. So I save a ton of oil, but haven't made light yet because of the time/heat/high sugar factors. Wish I could single pass, or two pass in only a couple hours.