acid wash

[amasonry]

Hey, guys need a little info on washes. can I do an acid wash followed by a soap wash with no rise in between? what is the proper process? flows are way down.

[wdchuck]

I cant claim to bean RU expert, but it would seem to me that the leftover soap in your machine would neutralize the aid solution somewhat if its not rinsed out.

[ecolbeck]

I cant claim to bean RU expert, but it would seem to me that the leftover soap in your machine would neutralize the aid solution somewhat if its not rinsed out.

I agree. An acid wash is.... acid. A soap wash is highly alkaline. One would neutralize the other and reduce or eliminate it's effectiveness.

[Russell Lampron]

The proper sequence is to flush the sugar, soap wash, rinse until soap is gone, perform acid wash, rinse, soap wash and final rinse. If you skip a rinse the chemicals neutralize each other. If you don't have enough permeate for the rinses you'll have to run a concentrate cycle with water to make enough.

[amasonry]

You got it Russ I only have 400 gallons of permeate and have a 250 ro. thanks for the advice

[maple flats]

With 400 gal and a 250 you should have enough. use 10-15 gal for cold rinse into head tank (pushing sugar), the permeate goes back into the permeate tank on this part., 10-15 gal soap wash, recycling, 5-6 minutes rinse, 10 gal acid wash, recycling, 5-6 minutes rinse, 10-15 gal soap wash, recycling and then 10 minutes rinse. On your rinse cycles except the first one pushing sugar, you will have about 50/50, That should be about 15 gal+ 15+ 15+22 minutes give or take rinsing to drain. Lets guess the 250 moves 7 gpm on rinse so 7x22= 160 or less + 3x15 (45) so you only use approx. 200-225 gal total. Where do I have any error? That was my experience the last 9 seasons (since I got my 250.)

[amasonry]

well got the washes done. noticed while crunching sap that the flow meters did not level out at 200 psi ,they used to. had to go to 300psi before meters read right. I did get my flow back. But feel my membranes are not doing well. Maybe I'm running them too hard? I have be taking 1-1.3% to 8.5% in one pass.

[eustis22]

What are the wash/rinse/soap amounts/times for 2 4X40 membranes?

[Russell Lampron]

well got the washes done. noticed while crunching sap that the flow meters did not level out at 200 psi ,they used to. had to go to 300psi before meters read right. I did get my flow back. But feel my membranes are not doing well. Maybe I'm running them too hard? I have be taking 1-1.3% to 8.5% in one pass.

Sap temperature has a lot to do with flow rates. Squeezing cold sap is harder to do and you get less permeate flow. When the membranes are new you need to set a benchmark to check membrane performance. To set a benchmark set the pressure and concentrate flow at the pressure that you normally squeeze at. Let the flows have a chance to stabilize before you take your readings. Write down those numbers and what you get for permeate flow. That will be your benchmark. There is a formula for how much to add or subtract from your benchmark for higher of lower sap temperatures but I don't know what that is.


What are the wash/rinse/soap amounts/times for 2 4X40 membranes?

Use about 15 gallons of water for a soap wash. Add enough RO soap to get the ph that the membrane manufacturer recommends. In most cases that will be ph 11. I start out with 2 tablespoons of soap. After the soap has had a chance to dissolve and circulate for about 10 or 15 minutes check the ph again and add more soap if necessary. As far as time and temperature goes my RO heats the water as it does the cycle and shuts off automatically when it reaches 42 Celsius. Starting out in the teens it takes an hour or so to get there. The soap works best around 103 Fahrenheit. I don't know how long you need to do the cycle if you have to heat the water and time it.

[amasonry]

so I have no times, no manual, and not much information about my ro. it is pre-internet and half-built by me. takes an hour and a half to do a wash. did not know the temperature of sap played a factor, will have to start checking I guess. so normal 250psi gives me 4.5% but last week 325psi gave me 4.5%. we will pay more attention to tomorrow's crunch. Thanks for the responses

[Russell Lampron]

I forgot to mention the time that it takes to do a rinse. There's no specific time and only a ballpark amount of permeate to use between soap and acid washes. What I do is check the ph of the permeate before I start and then I check the ph of the rinse water periodically as it exits the machine. When the ph of the rinse water is the same as the ph of the permeate it's clean enough to do the next wash. The time that it takes to do that and the amount of permeate used is about what it will take each time.

[Sugar Bear]

I forgot to mention the time that it takes to do a rinse. There's no specific time and only a ballpark amount of permeate to use between soap and acid washes. What I do is check the ph of the permeate before I start and then I check the ph of the rinse water periodically as it exits the machine. When the ph of the rinse water is the same as the ph of the permeate it's clean enough to do the next wash. The time that it takes to do that and the amount of permeate used is about what it will take each time.

Has anybody ever determined if a 100 degree permeate rinse is more effective then say a 50 degree permeate rinse.

What I am asking is, if one is short on permeate for cleaning and rinsing would it make sense to rinse with say 5 gallons of 100 degree permeate rather the 10 gallons of 50 degree permeate?


It seems that just about everything I have ever gotten on my hands comes off MUCH faster with warm water then it does with cold.

If so it would also make sense to do a quick final rinse at the very end of the final rinse with cold permeate just to cool everything down . That or make sure your preservative/storage is immediate and cool.

[maple flats]

All I go by is the directions that came with my RO, some places it says cold rinse, others it says up to 113F. If I try to draw up instructions for other units, I base them on what my RO wants. That may be a poor choice, but it's how I do them for those who have no manual to read.