Soap, Acid washes

[dcast99]

The leader Micro2 manuals states valve should be wide open for the rinses. It does not mention where the valve should be set for the soap/acid washes. I agree with Maple Flats that the vale should be closed some what so that the soap/acid penetrates the membrane to get a deeper cleaning. An open valve would only do a surface cleaning. I have been setting the valve at 150psi which gives me 3gpm of concentrate and premate. It would be nice if the manual stated where it should be.

[SeanD]

That may well be how a big RO is designed, but my experience using a Ray Gingerich 250RO was that the flow meters had to be about equal, concentrate vs. permeate or the membrane didn't get enough flow to get clean.

Hey, Dave. Ray recommends the valve wide open. How long have you been splitting the flow between C and P? I know you've always had good performance on your membranes (and I haven't).

[maple flats]

I split them after about 3 uses, because performance was going down. I figured the membranes were not getting properly cleaned and started trying a few things different, within 2 uses I tried balancing the flow readings and the performance went back up. I then did it that way for 9 seasons. After the 4th (or maybe the 5th) season I sent the membranes to Lapierre for cleaning and testing, the report came back that they were over 100%, which I didn't understand how they could be over 100% but regardless, I continued that procedure from then on.
To get the flows equal, I started with the main valve fully open, turned on the pump, then I started to slowly close the main valve until the flows were about equal. From there it took very little time to when I had to close the valve slowly more to keep the flows about equal, as the membrane kept getting cleaner. The soap wash rate of change was considerably faster than the acid wash rate of change, but I used the same method for both, as well as the rinses.

[SeanD]

Thanks. I tried it last night. Only took about 110 PSI to even them out and they were each around 2.4 GPM. I'll see what happens next boil. Thanks!

[mainebackswoodssyrup]

Sean,
If Dave doesn't mind I can email you a copy of his instruction/operation manual for the Deer Run 250. He made his own manual and it is very detailed. We bought Dave's RO when he retired from producing syrup. Unfortunately it's still sitting in the basement until we get the new shack built. Hopefully up and running for the 2025 season!

[SeanD]

Thanks for the offer, but I already have it. I've just been using Ray's original practices on the wash/rinse. Get that RO out of the basement and into use!

[SeanD]

Thanks. I tried it last night. Only took about 110 PSI to even them out and they were each around 2.4 GPM. I'll see what happens next boil. Thanks!

I wanted to cycle back and share the results of this new (for me) practice. In the 12 boils where I had used a wide open pressure valve in the previous rinse, I averaged 141 GPH on the first pass. In the 3 boils after switching to a 50/50 split on flow rates for the wash and rinse, I averaged 167 GPH on the first pass. That ends up around an 18% increase. It's a small sample size, but the numbers bear out what I was seeing. It was processing sap faster. I didn't crunch numbers for the second pass, but those rates were similarly faster.

The flow rates I have in my notes from the boils are actually higher than these averages. From time to time each boil, I note what the meters read, but those are snapshots from various points of each processing time. To keep things consistent for this, I divided the total amount of raw sap by the amount of time it took from turnign the RO on to the RO shutting off. I thought these numbers would trend higher because the total processing time includes the couple of minutes where the raw sap is flowing through pretty freely as I gradually increase the pressure. That's something else I tried this year - getting to my target pressure slower and introducing the recirculation later and slower.

I still want to get these membranes tested, but I'd like to pass on my thanks and results.

[craigwade2005]

I wanted to cycle back and share the results of this new (for me) practice. In the 12 boils where I had used a wide open pressure valve in the previous rinse, I averaged 141 GPH on the first pass. In the 3 boils after switching to a 50/50 split on flow rates for the wash and rinse, I averaged 167 GPH on the first pass. That ends up around an 18% increase. It's a small sample size, but the numbers bear out what I was seeing. It was processing sap faster. I didn't crunch numbers for the second pass, but those rates were similarly faster.

The flow rates I have in my notes from the boils are actually higher than these averages. From time to time each boil, I note what the meters read, but those are snapshots from various points of each processing time. To keep things consistent for this, I divided the total amount of raw sap by the amount of time it took from turnign the RO on to the RO shutting off. I thought these numbers would trend higher because the total processing time includes the couple of minutes where the raw sap is flowing through pretty freely as I gradually increase the pressure. That's something else I tried this year - getting to my target pressure slower and introducing the recirculation later and slower.

I still want to get these membranes tested, but I'd like to pass on my thanks and results.

Interesting to hear. Considering maybe trying this as well.
How long do you run your washes? Set amount of time or until it shuts off at the high temp?

[Bricklayer]

This is interesting. I’ve always been under the understanding that you don’t want any permeate being made when you are washing or rinsing. And the more flow over the membranes the better with the lowest possible pressure. I’m curious how well this would work with 2 membranes is series. If you’re taking permeate off from the cleaning solution then putting it into another membrane and squeezing it out even more is this good for the membrane ?
I usually run my RO about 70 psi with the valves wide open. I can max out the flow meter at 10 gpm of concentrate and permeate meter Dosnt even register much. The odd little dribble might come out. But nothing significant.
It would be interesting to know how they clean and rinse the membranes when we ship them out to be cleaned. I’m sure it’s not done in house by the maple companies. They Probley outsource it.

[SeanD]

It's a small sample size for sure, but there's also Dave's years of experience. We have the same machine and his advice has been really good for me. I'd like to have the membranes sent out this off season for a professional cleaning/testing.

My washes are usually for 20-25 minutes. The hot soap just recirculates. Both concentrate and permeate go back into the wash tank. It's a 10ish gallon tank. Then for the rinse, I just let the whole tote go through, so 275 gallons.

My rinses were never quite pinned on the meter. The concentrate would be around 4.5ish gpm and the permeate would be nothing. Splitting the flows puts each side at about 2.4 gpm.