First run with XLE-4040s

[Brent]

Tonight was the first run with the XLE-4040 membranes. I was favorably impressed.

After getting the air out and stabilizing the system the permate flow was 3.5 GPM and concentrate was 1 GPM.
So I was going through about 270 GPH of sap on a 150 GPH machine.

60 GPH of 6.7% does seem too bad. I was trying to get it
to give me 8% from the 2.4% raw sap and I suppose it would have done it if I pinched the concentrate flow back even more, but that won't keep up with the new evaporator. I think to feed the evaporator I'm going to have to open it up to near 2 GPH of concentrate. Didn't test that yet.

We'll see how it does when the bugs do there thing and it all gets slimy inside, after a couple thousand gallons. So far, so good ... except that I dumped 250 gallons down the hill while I played ... but it was 4 or 5 days only anyway.:D

[wiam]

Yesterday I took 1.6% to 11% at .4 gallons of concentrate and 2 gallons of permeate / minute. This is way better than the nf-90 membranes I ran last year. This is on a 1986 memtek RO225S 2 membrane machine. So far I have kind of played with pressure and not decided where to run, but boiling 11% is fun:)

William

[danno]

I'm glad you started this thread - I wanted to share our experiences on the XLE 4040's, as I really feel like we're flying blind on how to get best performance on running and washing these. I'm running 2 XLE 4040's.

First question - what pressure were you running?

I've been running them about 350 psi and getting .7 concentrate, 2.5 permeate. Sugar increase from 1% to 7% on single pass. As noted in other post, .4 concentrate will get me over 10% with no noticeable sugar passage. Permeate drops down to 2ish on permeate after a few hours. Recovery after full wash seems best. Rinse helps, but not as good results as full wash. I've been running my wash at 13 ph/77f. Very low PSI (50ish), 2 gph concentrate, very low permeate, then a long rinse on the same settings.

Rather than pinching, I've been recircing sap in my holding tank, bringing final pass to about 10-11% Not bad, when your starting at 1%.

[Brent]

I started running at 50 psi and gradually worked up to flat out for my rig, which was 300 psi. I went up in 50 psi steps with concentrate coming out at 4.6% and increasing every time I stepped it up. Just when I wanted to go 10 minutes or so at 300 psi, I sucked the feed tank dry. So
real numbers are yet to come. I rinsed with the permeate.
I dumped the concentrate over the hill because this was the first run to get the SMBS out.

I like what I see so far.

You must run the RO for more than a couple minutes before you fire up that 3 x 10 .

[sapman]

I'm using the 8" version, and have been impressed. Benchmarks outperform initial RO ratings. Last night was the first time I single passed, since it's so warm. I was able to go to 13%, at about 1-1.4 gpm concentrate, 360 psi. Not sure if the benchmark was quite as good after washing this time.

[Brent]

:)
Ran the first real load thru the XLE-4040s last night. Got a pair of them on our machine. After 5 minutes running only the feed pump to expel air, I gradually cranked up the pressure to 295 where it stayed through the whole run ( I raised the stock tank to above the pump ... end of problems with pressures) Pinched the concentrate down to 0.8 GPM and after 10 minutes it was making 8.7% from 2.7% sap. The permeate flwo started at 2.8 GPM. About 30 minutes later the concentrate was still at 8.7% so I openned it a tweak to about 0.8 GPM. and the concentrate dropped to 8.6 and stayed there till the tank was empty. The permeate flow drifted down to 2.25 in the first half hour and stayed there.

In the end I had 90 gallons of concentrate in 1:35 minutes of running. 174 GPH of 46 degree total throughput.

Tested the permeate and the digital Misco said it was 0.1% sugars but as has been noted, this is below the limits of accuracy of these things so I tried the sap hydrometer and it sank to just below the 0 mark, which is what it should have done at 46 degress. I then tried the TDS meter and it flickered between 1 and 2 PPM.

So far, I think these things are doing well.

Started a rinse with the permeate and went to bed.

90 gallons of near 9% ... finish the plumbing and flood the evaporator today.:)

[danno]

Brent - my results are very similar to yours - except I'm not starting with 2%+ sap. What did raising your tank do to your pressure? How much pressure before and after?

The bottom of my tank is about 6" higher than my RO feed pump and I have pressure issues. Max feed pressure is 20 PSI and pumps often shut down until I've built enough pressure in the system. It would be hard to lower my RO or raise my tank. Tank is 1000 gal with releaser above and a roof 4" above the releaser, but just curious how much raising your tank helped your pressure?

And yes, with the 3x10, I start RO'ing couple hours before I boil.

[Brent]

Gave the new membranes a real good run yesterday. Finished about 200 gallons of concentrate ate 7.6 to 7.8% from 2.5%

Interesting observation. Sunday night I flushed the rig with 200 gallons of permearte. Started up Monday afternoon and the initial permeate flow was just over 3GPM. That dropped off quickly, maybe in the first 15 to 20 minutes of the run, to about 1.8 - 1.9 GPM and it stayed there for the rest of the run. Processed about 900 gallons with no significant change in rate. I don't know if this will last, but I am getting to think that these things don't foul very fast. Time will tell.

Update Wednesday night. Ran another 275 gallons. Same deal. Started at around 3 GPM perm and in 15 minutes it dropped off to 1.8 and stayed there till the tote was empty. 7.5% from 2.5%. I wonder if the early high rates are because all that stainless is still warm and warms the sap. Once it chills down to the same temp as the incoming sap, the performance numbers change. I'm up over 10 hours now with no detectable change in the performance. I wonder how long the fairy tale continues. Love it :)

[Gary in NH]

Brent,

You are correct, it is mostly temperature related. Warmer liquid temps equal more permeate. In addition the concentrated sap has a higher viscosity than the rinse water that remains in the system from flushing. As everything cools off and the sugar concentrates the permeate will drop off and output will equalize. I have commercial RO customers on municipal water supplies that have higher permeate flow in the summer when feed water temps increase and vice versa in the winter months.

[sapman]

Is everybody soap washing their membranes after every run?

[Brent]

I rinse after every run.

Have not done a wash cycle yet. Only 3 session and maybe close to 10 hours so far total time. I am going to go at least one more run before I wash. I think the flow rates will tell me when it's time. Still in the experimenting stage with these membranes.

[Brent]

Danno Raising the stock tank did not have any impact on the running pressures, except that it was much easier to purge the air out before I even started the pumps. This rig has always run consistent pressures once the air was out. I just neglected to put the skids under the tank before I started.

[Brent]

Yeh Gary I think you're on the money. The remaining permeate would make the initial rate soar.

[danno]

Danno Raising the stock tank did not have any impact on the running pressures, except that it was much easier to purge the air out before I even started the pumps. This rig has always run consistent pressures once the air was out. I just neglected to put the skids under the tank before I started.

Thanks Brent - I've pretty much determined that my low pressure with my feed pump is a pump problem, not a sap intake issue. Even when my pre filter clogs (which was happening constantly when we had that warm weather sap last week, much better today) and sap can't pass through the pre filter, and thus tremendous back pressure, the low pressure pump still would not go above 20 psi.

[Brent]

Well after nearly 15 hours the permeate flow started to drop off, fouling and likely colder sap played a factor. Gave them a wash cycle today and right back to 1.8 GPM making
0.8 GPM of 7.8 to 8%. I don't see any problems with these at all.

PS really rocking this year. RO running sweet, bigger evaporator with Inferno Arch and a Steamaway. Keeps you hopping.:)

[danno]

Brent, if you're getting to 8% on .8 gpm of concentrate, I'm guessing you're starting with pretty sweet sap - 2.5%ish?

[wiam]

Brent, if you're getting to 8% on .8 gpm of concentrate, I'm guessing you're starting with pretty sweet sap - 2.5%ish?



I have been doing about that with 1.7%, but I like cranking it to 11%.

William

[Brent]

I have not checked the raw in the last few days but we normally average 2.4 - 2.6

[Brent]

Well maybe another lesson learned. Yesterday I pinched the concentrate flow down to about 0.4 to 0.5 GPM after a half hour the permeate flow dropped down to less than 1 GPM so I openned up the concrate wide open to give it a flush, then went back to the 0.8 GPM on the concentrate and the permeate settled back to it's usual number of 1.8 GPM. I'm thinking the lesson is that you don't try to go much past 8% on a single pass. I'll try it again some day to see if it repeats.

[wiam]

I have been going to around 10-11% in one pass. Concentrate at .4gpm. Drops off in about 3 hrs. Then I do a rinse for 15-20 minutes and brings it right back. I am thinking about adding a third membrane.

William

[Brent]

I have been going to around 10-11% in one pass. Concentrate at .4gpm. Drops off in about 3 hrs. Then I do a rinse for 15-20 minutes and brings it right back. I am thinking about adding a third membrane.

William


What pressure are you running at ? My rig only goes to 300 psi.

My impression is that these membranes flush clean much better than my old PVD-1s. With about 8 hours non-stop yesterday they were still running 1.8 / 0.8. Rinsed last night and if we get a run today I'm just going to keep going. Warmer with thunderstorms !? YUK.

[wiam]

My older memtek will go to 500. Joe advised me to not go that high. I have been running them about 400 most of the time. Today I was going from 2% to 10% in one pass at .6 gpm at 500 psi. Still running about 3 hrs before needing a rinse.

William

[wiam]

Finally boiled down some permeate. Caught some permeate from 500 psi of above post yesterday. 20 qt stock pot about 1" from top. Boiled on turkey cooker down to just enough to fill hydrometer cup and floated just below 0.

Has anybody else tested permeate with their xle?

William

[Brent]

I should do the same test before the season's over. I'll save a pail today.

Going to do some more TDS measurements. I've only tried one so far and that was good.

[Kngowods]

I have a 125psi pump @10gpm could I, and what would happen if ran my filtered 2% sap straight threw a xle-4040 no recirc pump what % and gpm would I get? I'm sure someone had to try this.

[danno]

I have a 125psi pump @10gpm could I, and what would happen if ran my filtered 2% sap straight threw a xle-4040 no recirc pump what % and gpm would I get? I'm sure someone had to try this.

What would happen is that you wouldn't get a whole lot of permeate, thus your concentrate would not be a whole lot higher than the 2% you started with. I know when I running my system through rinse cycle at 100-150 psi, I'm not creating whole lot of permeate. Better than nothing , yes. Worth it, idk.

[Kngowods]

So could you just pinch off the concentrate some

[wiam]

So could you just pinch off the concentrate some

Yes, that will up the permeate. It will also cut the total flow into the machine.

[Kngowods]

So what do you think the specs would be? How would that improve my concentrate? My goal would be to improve the concentrate by 2% would that be possible with this setup or would I need a higher pressure pump

[mustanger]

Filmtec says the XLE4040 membrane is happy at 100 psi. Seems to me that a 125 psi pump ought to make it work.

[Brent]

Last year our pump shaft broke on the very last day, just as we started the last wash. So we took the pump apart and found the pump vessel, about
36" long an 5" diam, was rolled and welded ... not a real tube. The inside of the vessel had a gap about 0.020" deep and 3/8 to 1/2" wide running top to
bottom. Worse still, the diameter was not consistent. At the narrowest end the seals and O-rings where mushed and had to be leaking. We are honing
out the grove and going to make the walls parallel, then machine the pump mounting flange square to the walls so there is no stressing on the coupling
between the motor shaft and impeller shaft. The way it was it flexed every revolution. Lots of shaft failures on this model.

But the bottom line is that we think there was some significant leaking around the O-rings and seals. It will be interesting to see if we can see and
improved performance this year .

Oh yeh ... and without the pump we could not flush / wash the membranes so they are being replaced to start this season.

[wiam]

Filmtec says the XLE4040 membrane is happy at 100 psi. Seems to me that a 125 psi pump ought to make it work.

I run mine a about 400 psi. This will be the 3rd season on them. I had them cleaned after each season and they flow tested right where they should. :) I have also boiled down 20 qt of permeate to just fit in a hydrometer cup and had hydrometer still sit on the bottom.

[tuckermtn]

I just received my new 4" and 8" XLEs. Is there anything I should do to wash/rinse them/prey to them - before I run sap through them?

looking forward to new membranes...and hopefully lots of sap.

[wiam]

I have had dealers tell me just need a rinse. I always run a wash and then full rated rinse.