Figuring out a used RO

[cjf12]

Bought a bunch of used equipment together to get us evaporating for the first year at least a little more professional. One piece was a homemade ro. On this beautiful 0 degree day i decided to figure it out. After fixing a few broken fittings and stiffening the frame i pulled out the membrane.
It appears it was never cleaned when done. Only the bottom 12 inches had old sap now vinegar in it. Rest was dry. 4 inch mes 4040 membrane.
Is it junk? What would i do to use it? 240 bucks to replace it. Trying my options for marriage sake. Any help as always is greatly appreciated.

[cjf12]

717008
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Picture of the membrane.

[Russell Lampron]

I would completely immerse the membrane in water and let sit for a few days to get it soaked through. Then when you can run the RO flush it with well water. About 100 gallons should be enough to get the vinegar out. After you get it wet store it wet so that it doesn't dry out again. When you have sap to concentrate check the permeate to see if it is passing sugar. If it doesn't pass sugar you're good to go.

[cjf12]

Is it possible to test it before hand to know. Mix up 10 gal of sugar water and run it thru?

[Russell Lampron]

Is it possible to test it before hand to know. Mix up 10 gal of sugar water and run it thru?

I've never tried that but it should work. You probably want to use 25 to 50 gallons of sugar water to get a good test though. When you are done running that through boil a gallon of the permeate down to about a quart and test that for sugar. If there is any it will be easier to detect.

[Bricklayer]

I brought some old membranes back to life last year when I bought my commercial RO and converted it to a maple RO.
I just constantly flushed it with clean well water that's not hard or chlorinated. Then when I had enough permeate I let it soak in permeate for a couple days. Then did a warm soap rinse. Then rinsed. Then acid wash. Then soap again. Then rinsed real good. The warmer you can get the rinse and wash water the better. I forget how warm the membrane can take but it's on MES website. I'm sure the membranes are still good. You even let the acid and or soap soak the membrane in the RO for a couple days to clean it up. You'll be surprised how much it works. Just run it on low pressure meaning the concentrate valve wide open or just on the feed pump if you can. And once it's clean you can turn the pressure up and if you have a TDS meter you can measure the tds of the permeate. If it's like 0.01 or in that range with well water your good.

[cjf12]

What soaps and acid are you using? I have a heat plate exchanger on an outside boiler. Thinking i could just let it run hot water through for a while. Cost is nothing but wood. Thats cheap for a tree guy.

[cjf12]

Boy this gets time consuming. Not use to staring at a screen this much.
From search on this site it seems ph and temperature is whats important for cleaning.
Thoughts on this.
Use wifes lye for soap making to raise ph to 10 and start with warm water and allow pumps to heat not above 113 degrees. Mes says 2-10 (1-12) for ph. And 113 max temp. Assuming first numbers are continous and second numbers are for short term.
Rinse thorough with spring water and the peemeate. Good to go.
????????

[Bricklayer]

Lye will work but don't quote me on that. I use the CDL RO soap. And citric acid from a health food store for the acid wash.
First thing I would do is just get some warm water or just even water through your membranes to flush them out. That will at least get them wet. And even running it on low pressure will give you some permeate. Just throw the concentrate out.
Then rig up some way of recirculating the wash. I used a new laundry tub when I was building my RO. But even a tote will work to circulate the water. Basically when washing you have your permeate and concentrate gong into the same tub and your drawing from that tub also so the soap is going through and back in. I give it a stir every now and then to mix it up. The soap will foam up quite a bit. It's like dropping a bar of soap in a jacuzzi.
If your RO has scale build up and crud in the lines and the flow meters. The acid wash will clean that up. Let it sit over night too.
You could send your membranes out to be cleaned too.MES will clean them or any other Maple dealer will do it. Almost cheaper to buy new 4x40's though.