HELP - 50 gph parts list ?

[arcticair]

I would like to build a simple 50 gph r/o . If anybody has built one of these I could sure use your help in picking a filter and pump ! New to this and have to be able to run it from a generator. Thanks for the help

[bowhunter]

The answer depends a little on what you want to do. Do you know how much water you want to remove? I usually size them for 75% which will concentrate 2% sap up to about 8%. You would need a 4inch diameter by 40 inch membrane. An XLE, NF270, NF90 or maybe a 4 inch MES should work. You will need a pressure pump something like a ProCon 265 gallon per hour capable of about 250 PSI. I would recommend a 1 hp motor for this pump but you probably can get by with a 3/4 hp motor. Other parts are two flow meters: one for concentrate and one for permeate and two needle valves: one to control concentrate flow and one to control concentrate recirculation back to the pump. You will also need a 5 micron sediment filter before the pump, probably 21 inch element. You will also need a pressure gage reading up to 250 psi. of course you will also need tubing and fittings to plumb up the system. You can use this list to get started estimating the cost to see if you want to move forward. Several people on this forum have home made RO systems and most would be happy to share information with you.

[arcticair]

Wold that not give me an r/o capable of 2400 gallons a day ? I would like to remove at best 80% of the water , I was looking at the xle4040 filter and it shows an applied pressure of 100 psi - why a pump capable of 250 psi ? Guess I should have mentioned I would like to process 600 gallons a day. My sugar contend never gets above 1.2 % at peek.
I was thinking a 2.5 x21 or 40 would be large enough with a procon pump capable of 3 gpm .

[bowhunter]

Most homemade RO's aren't equipped with enough safety devices to effectively run unattended when you are in bed or at work. etc. The sizing is generally done so that the RO step can be completed in 8 hours or less so if you have 600 gallons of sap you need a system capable of processing 75 gallons per hour. That requires a good 4 x 40 membrane. The membranes have a rated capacity at a given pressure. The XLE's are tested at 100 psi and 77 degrees F or 25 degrees C. RO and nanofiltration membrane permeation rates are very sensitive to sap temperature and sugar content. That's why the operating pressure on theses homemade systems is generally 150-250 psi. As an example a membrane that is rated for 1000 gallons per day of permeate at at 77 degrees F only passes about 500 gallons per day at 39 degrees F. Sugar content of the sap and concentrated sap drive up the osmotic pressure which has to be overcome by the pump pressure. For example if you concentrate up to 9% sugar the pressure has to be increase from 100 psi to about 200 psi to pass the same amount of permeate. You can add some safety devices such as a pump pressure switch and temperature switches and get by with operating unattended, but you still have to have enough sap storage and permeate storage to run for several hours while you're not there.

[Clinkis]

Y
Wold that not give me an r/o capable of 2400 gallons a day ? I would like to remove at best 80% of the water , I was looking at the xle4040 filter and it shows an applied pressure of 100 psi - why a pump capable of 250 psi ? Guess I should have mentioned I would like to process 600 gallons a day. My sugar contend never gets above 1.2 % at peek.
I was thinking a 2.5 x21 or 40 would be large enough with a procon pump capable of 3 gpm .

You usually need to run an XLE around 250 psi or higher to maximize its capacity with sap. To each their own but I prefer using the Procon pumps without pressure relief. I normally run mine around 260-270 PSI. I have also plumbed and wired in high and low pressure switches which will allow you to run your RO unattended. There easy and inexpensive to add. If batching sap the low pressure switch will kick off the RO when you are out of sap and the high pressure switch will protect (obviously) against high pressure. Mine is set to 280 psi. Once you learn your RO a bit you can use high pressure switch to recirculate in a tank to a desired level unattended.

Also, if you are looking to remove 80% of your water, a single XLE will do 50-60 GPH on average at that level. You are looking at around 12 hours per day to process 600 gallons. May want to consider a bigger design. I produce on average 200 gallons per day of sap and I RO out 80% of my water and I can barely keep up with my evaporator. I'm expanding to a second post next year.

[arcticair]

Thanks for the help , I will go with the xle2540 , I am procession birch sap which is mostly water , if I remove half of that water it is a great improvement. My evaporator will boil about 60 gallons an hr without a hitch. My next question is the proper procon pump ? GPM rating should be for that filter ? I am about 35 miles from the nearest hydro pole LOL . Adding safety switches for high pressure and low or no flow control are an easy addition . ( limited with generator size ) Again thanks guys for the support.

[bowhunter]

If you're processing birch sap at 1.4% and removing 50% of the water you can run about 50 gallons hour through this set up with recirculation. It will produce 25 gallons per hour of 2.8% sap. You could obviously recirculate back to your sap tank and concentrate it up while you're not there. Concentrated sap can get pretty snotty and doesn't keep very long. A 165 gallon per hour ProCon pump should be fine for this setup. You might be able to get by with 1/2 HP motor, but you probably won't be able to run much over 200 psi without overloading the motor.