R.O. for 15 GPH of 8-10% Concentrate.

[Jolly Acres Farm]

Here's what I have, a Mason 2x4 XL flat pan. I average 10-12 GPH with a max of 16 1/4 GPH evaporation rate. I'm looking to get into a R.O. that can take a 1.9 average sap to 8-10% at a rate of 15-20 GPH finished concentrate. This way it will be sized to my evaporator and I can boil it as I R.O.

Does anyone have any experience with this size of a set up. I ran 117 taps this last year and had some long 18 hour boils on good runs. I'm looking to tap around 175-200 Sugars this coming year and need to find and/or built a R.O. that fits my needs/ sized operation. I have a budget of around $1200 for this project.

I welcome all ideas and testimonies with your R.O.'s bought or self built.

[Bricklayer]

If you check out Steve Child's RO videos on YouTube I think the second RO he demonstrates will do about 15gph I think. Pretty simple unit.

[bowhunter]

You can build a single membrane ro using a ProCon pump for less than $1,000 which will handle up to 200 taps. You don't really have enough sap to run 8-10% and boil 15-20 gph on 200 taps so you will have capacity to spare with this set up.
Membrane - 2540 (2.5 inch x 40 inch) Filmtec XLE or NF270/NF3 (nano filtration membrane)
Membrane housing - 2.5 x 40 inch PVC or stainless steel
Pump - Procon 140 GPH or 165 GPH
Motor - 110v 1/2 HP or 3/4 HP carbonator motor
Concentrate Flow Meter - Blue White Model F55250L/A (rated to 250psi) (You can order the concentrate flow meter with adjustable flow to control concentrate flow
Permeate Flow Meter - Blue White Model F55375L (rated to 250 PSI)
Recirculation needle Valve - 3/8 inch
5 Micron sediment filter - 10 inch

I prefer the nonofiltration membranes because they will give you a little more capacity (about 25%) at the same conditions. Many guys prefer the XLE's because they are less likely to pass sugar at the higher concentrations (above 12%)

I have almost the exact system and I was able to process about 24 gallons per hour of 2% sap up to 8-9%. Of course you only get about 5 gph of concentrate at these conditions. You should be able to run 30 gph of sap and remove 70% of the water yielding about 9 gph of 6.5% concentrate to match you evaporator.

[Jolly Acres Farm]

Thank you bowhunter this is what i'm looking for. 9GPH of 6.5% would work out good for me. Do you have any ideas how to bump that up to a yield of say 15 GPH of 8%.
With the setup you described is that in a single pass or recirculating?

[bowhunter]

It's single pass with what I call internal recirculation of concentrate from the membrane outlet to the pump inlet. You do this to keep the flow high and the sugar concentration relatively constant over the length of the membrane. This minimizes membrane fouling and improves average performance. All manufacturers recommend a maximum recovery of 15%. This means removing no more than 15% of the water as permeate during each pass through the membrane. You really can't bump this system up to 15 gph of 15% concentrate. You would need a 4 x 40 membrane and a 350-400 gph pump for a system this large. To be clear you really need 500 taps or so to justify a system that large.

[Clinkis]

I run a single xle 4040 with 200 taps and I wouldn't want any smaller. I get 30% recovery rate with 190 GPH pump without issue. Any more then that I start fouling. To each their own but I would rather have a little too might capacity then not enough. Especially considering it's not a huge expense to go to the larger membrane design.

[bowhunter]

I know a lot of folks run at 30% recovery rate single pass without recirculation, but as you say you tend to get fouling above that level. If you ever need the additional capacity you can add recirculation and a 265 gph ProCon pump and easily remove 75% of the water on a single pass at 50 GPH. This would allow you to handle 300-400 taps with your 4040.

[Jolly Acres Farm]

Bowhunter,
I'm liking the idea of 50-75% water removal on a single pass. Would there be any down side to this system vs. the smaller system other then a little more cost up front? Plus I'm sure that each year I'll keep adding taps, at least until I run out of hours in the day to boil it all.

[bowhunter]

As long as you use enough pump to keep the membrane reasonable clean the bigger systems should work fine.

[Jolly Acres Farm]

What do you mean by 30% recovery rate? Is this removing 30% of the water per pass or removing 70% of the water per pass?

[mellondome]

30% water. When running your ro you will see that once you pass about 15% you will see no/very little increase in water removal per minute without recirculation. Can you get 50% to 75%? Yes, but you will see that rate of water removal will actually decrease over time due to membrane fouling