Your thaughts on designing a RO system for under 300$

[sugarphil]

Hello everyone,

I'd like to design a low cost RO system as a proof of concept for my father in law's new maple shack. He's got 450 taps under vaccum, a 375Gal holding tank and a 300-450 CDL EVAP. I'd like to keep the costs to a 300$ budget, because if he finds it too much of a burden to operate, I could still resell it to 2 other cutomers that could find it interresting for that amount of money. If he decides to operate it in the next years, I would like to be able to reuse the components as part of a bigger build.

There's my inital parts list and associated costs:

- 2 x 2in x 12in plastic membrane housings (10,50$ each) http://www.wateranywhere.com/product_info.php?products_id=3002

- 2 x NF membranes ratted at 200GPD @ 150 psi, 77F and 15% (50$ each) http://www.wateranywhere.com/product_info.php?products_id=10683

- 1 x Procon 140 GPH pump (102$ each) http://www.wateranywhere.com/product_info.php?products_id=10065

- 1 x 1/2 hp 48YZ electric motor (deal yet to find)

- 10 in sediment housing and filters (I already have one)

- Pressure gauge, fittings, tubing and needle valve

I already have a 48 type frame motor rated to 1/3 hp but I could not find the mounting details for the pump (how do these exaclty connect to the shaft is still a bit a mystery to me). I'm on the lookout for cheap 1/2 hp used motor with the appropriate frame (from pool pumps maybe) that I could buy.

I plan on running the setup at around 150 PSI (if the filter housings can take it) on sap thats close to 40F at about 139GPH flow rate and try to reach about 10 GPH permeate flow (half of the OEM 77F rating). I'll take sap at 2% coming right from the receiving top end of the holding tank and delivering the concentrate at the bottom of the tank (closest to the feeding valve of the evap). This way I think I'll get the most water out (even tough it won't raise % much)

I thought about going with aquatec pump(s) but from what I could make from their flow vs pressure curves, it won't provide enought flow at such pressure.

If any of you have better idea for more performance for this verry limited budget build, or if you've built such a system and learned ways to better limit the costs, I'll be more than happy to hear it. (better suited membranes and housing or cheaper pumps).

** I understand that for RO, the investment to performance curve is probably somekind of an exponential function (ie: 4000$ invested will get you 3000 GPD, but 6000$ will get you 10000 GPD) but I cant afford to go much higher as this is pretty much an experiment for me.

Thanks

[bowhunter]

You really can't build much RO capacity for $300 unless you buy used membranes, housings and pumps. Most of your components won't be useful in a larger build..maybe the ProCon pump for a modest size system and some of the pressure gauges and a few fittings. It would probably be less expensive to take your father-in-law to a syrup producer who is using RO for him to see. The technology is well established in maple syrup production and has be around for many, many years. RO has a huge impact depending on how much water you remove. I think 70-80% water removal is pretty typical for large operations. He probably needs something in the 125 gallon per hour range to remove about 50% of the water with the size of his current operation. Unfortunately that's going to cost more like $1,500 to build. 4 x 40 inch NF membrane, 250-400 gallons per hour ProCon pump, etc.

[sugarphil]

Thanks for the tip, your right I should try and arrange some visit to an RO sugar shack. Maybe the he'd be more interrested in having one to eleviate the burden. Or I might skip this season and if we get way much water then what the system was built for, I'll come in with the idea of a 120ish GPH setup.

[sugarphil]

By the way, I found out a good potential source for procon pumps and motor assembly, coud be used soda drink carbonator. I learned somewhere that Procon pump are used extensively in carbonated beverage dispensing machines around the world. Ebay seem to have a whole lot of these used ''carbonator'' unit around 100$ that comes with the pump and the motor already mounted on one another.

The drawback is that most of these unit assembly seem to be rated at no more than 125 GPH and 1/3 HP for the motor. Nonetheless, they seem like good deals if your on the lookout for a low cost pump with those outputs and their pretty much ''plug-and-pump'' when you get them.

I think they could be usefull replacement/upgrade to all the Aquatec builds out there.