600 RO Flow Rates

[Amber Gold]

I wanted to check in to see what people are getting for flows with their 600gph RO machine. To see if mine's in the ballpark of where it should be.

H20 Econox 600 (non-expandable) with a new CDL membrane. This season, I'm getting 2C/5.75P flows with sap temp at 37F and pressure at 300-350psi. SSC is ~1.5%

I'm sure flow rates will vary a bit manufacturer to manufacturer, and membrane to membrane, but shouldn't they all be about the same??

Thanks

[Sunday Rock Maple]

If I'm understanding if right you are getting 465 gallons per hour. What's your concentrate percent? I generally get 4x the raw sap at about 500 gallons per hour on a mark e8

[Russell Lampron]

The flow should somewhat be equal to what the machine is rated for. I'm assuming that your numbers are in gallons per minute which is 120 gph concentrate and 345 gph permeate. I'm coming up with 465 gph total which seems a little low. My 250 was doing 1.5C/3P at 250 psi and 51*F which is 270 gph this morning. I don't know what the ssc was before I started.

[Amber Gold]

Yes. that's 2gpm concentrate and 5.75 gpm permeate....or 120gph concentrate and 345gph permeate...465gph total flow.

I thought it sounded low too. The first time I ran the membrane, it was about 6gpm permeate, but they seem to have settled in at about 5.75gpm after running it 4-5 times.

[maple flats]

My 250 RO got 1.2 gpm C and 3.3 gpm P today with a sap temperature of 41 F. Thus 4.5 total x60 = 270. Yesterday my sap was at 38 F and my flow total was 255 gph. I think you have an issue. Talk to the mfgr.of both the membrane and the RO.
However, if the sap is at 35 F I get slightly under the 250 rating

[Shaun]

I have the same machine on a 4 year old h20 membrane. I ran the machine last night with 44 degree sap at 410psig at 8 permeate and 2 concentrate. This brings 1.8 sap to about 9.5 or so. I can always get 600gph even with 35 degree sap although the pressure can creep up to 440psig.

[Amber Gold]

I appreciate the replies.

I was wondering the same thing,so went back through last year's thread and found out that I was getting similar to flow rates. And as the season progressed the flows got worse, and I assumed the membrane was plugging up and I tried getting it back but couldn't. In hindsight I'm wondering if I'm having issues with the recirculation pump. What do you guys think?

I've been benchmarking every run, and the first test was at about 12.75 GPM but then the membrane settled into about 11.2 GPM. My last run it benchmarked at 10.5 GPM. I run awash cycle after every use.

Tonight, I watched the flows better, and the membrane started at about 300 psi with two GPM concentrate and eight GPM permeate but then within an hour the pressure climbed to 380 psi and the permeate flow rate was down to 5.5 GPM. I think this means the membranes plugging because the flow rates are going down but the pressures are going up. Am I in the right track?

[Shaun]

I have a little excel sheet that I record readings on. I added the time I start the machine and the time I record the readings. I usually wait 45 minutes to an hour before I write them down and figure this will give me a good idea of fouling and overall operation.

[maple flats]

In my experience anytime I see the through put drop anywhere near that I do a quick permeate rinse, the membrane is fouling. How many micron is your prefilter and when you change it is it uniformly soiled?

[blissville maples]

You should see, with a real machine not these homade knockoffs, around a total of 6-9 gpm combined. As you crank down concentrate flow permeate will increase so you should always be around 8ish gpm. Many people don't run the proper psi. You should run around 400 psi for max potential and this will increase your gpm output.

You will never get 600 gph out of a membrane, expect around 450-500 gph depending on how clean it is. A recirculation loop or multi stage turbo pump is the only way to increase that with a single membrane.

[GeneralStark]

Josh, I don't know anything about H20 machines but I see Shaun is running at a higher pressure and getting higher permeate flow. Have you tried running at higher pressure like he is? What is the high pressure rating for the machine?

It seems to me that a brand new membrane should be performing a bit better. My Elite 500 with a membrane on its 3rd season generally does about 480 gph pretty consistently now and was just over 500 gph when the membrane was brand new. This is running at about 380-400 psi.

How long are you running the machine before rinsing? 802Maple's advice to me was don't go more than 4 hours... something about "keeping the tool sharp"...

[Amber Gold]

The RO's been running about 4 hrs on the first pass, and then another couple hours to get through the second pass. When switching from first pass to second pass, I could do a quick permeate rinse.

Last night, the pressures were 380-400psi with permeate flow between 5.5-5.75gpm. I can go higher than 400psi, but thought it was bad for the membrane (makes it harder to clean or something), so I haven't. I'm guessing it max's out at 500psi.

Benchmark flow last night was again 12.4gpm. I benchmark by setting the RO at 225 psi, concentrate at 3gpm, take a permeate reading, and then temp. correct it. My corrected benchmarks for the season are:
13.9
13.2
13.0
13.1
12.5
12.4

[Maplewalnut]

Josh- Very similar situation. I have a Lapierre machine and a cdl membrane. I start around 2gph and 7.5 on permeate. May run like that for an hour but rates slowly drop. I do increase my pressure and after a 4 hour run will wind up around 2gph and 5 on permeate but that is with 10-14% sap. I never go over 450 psi. Cleans right up no problem and back at it the next day. If I go over 4 hours run time, I will run 100-150 gallons of permeate through and restart

Mike

[Amber Gold]

A couple of things.

If I should be getting it, I'd like the extra 2gpm permeate because I'd get through my first pass faster and my first pass concentrate would be sweeter...making my second pass concentrate sweeter...

The other thing is having the benchmarks drop, and if it continues...that means the membrane is plugging up. I've been fortunate, that most of my runs have been about 1100 gal, so I've been able to get through it OK. That'll change when my other sap seller starts delivering sap.

Basically just trying to get ahead of an issue, if there is an issue.

[Shaun]

I guess I look at it this way. I adjust the flow meters to 600 gph or 8c and 2p and adjust the pressure to meet that. Usually run around 410psig. If the pressure starts creeping toward 440 or 450 I wash. I usually do a hot rinse and only wash a few times a season. I have 1350 permeate and try to wash when I can rinse with 1000 or more. Usually process about 20k sap a season, so not really that much. Not sure about the pressures but the machine runs smooth at 400psig. The rattling you hear when washing at low pressure is the pump operating off the curve.

[Amber Gold]

Update.

Working under the idea that there's an issue with the recirc pump, I took the cover off the recirc. pump electrical connections. I wanted to see if the contacts look good and see if I could check voltage at the terminals. Turns out you can't do this because the capacitor and male side of the terminals are mounted to the cover. I put the cover back on and ran the RO last night.

Right off the bat, I could see things were better. Perm. flows started out higher and stayed higher. It settled in at 2C/7P at 400 psi w/ sap temp at 46F. I gained 1.5gpm on the permeate side. At my scale, 90gph throughput increase is a significant improvement! After my 2200 gal first pass, it dropped barely below 7gpm and pressure was still at 400psi. Ran 300 gal of permeate (802Maple tune-up), and the second pass was at 2C/2P and 400psi and the concentrate was in the upper teens. Until I run it a few more times, I'm not going to say things are all better, but they have improved. Taking the cover off and putting it back on is the only difference from one night to the next.

My best guess is the terminals were not making a good connection, so not all the voltage could get to the motor. I'm guessing the connection is better, but maybe not perfect...still not getting 2C/8P...don't know. The issue I see with the electrical box design is you can't make the physical terminal connection yourself, you're relying on the connection being good when you install the cover...and you can't test it with the pump operating.

Thanks Shaun. I always wondered about that noise when on a wash cycle. Makes sense now that you mention it, and I agree, running it around 400psi seems to be in the pump's sweet spot.

[eagle lake sugar]

I have the econox 600 as well. I can usually start the season running the full 600gph or close to it while concentrating from 2% to 8%. Don't be afraid to increase your pressure, 400 psi is nothing for these machines, sometimes I've approached 500. When double passing, I run it on 6c and 3p to bring it to 6%, then the second pass I can easily bring it to 14% to 16% running at about 4p and 2.5c.

[Jeff E]

You can play around with your flow rates and change your total input volumes quite a bit. The way I think about it is I want to maximize the permeate. I will send my concentrate back to my RO feed tank, open up my concentrate valve, say go from 2.5 gpm to 6 gpm, and 'flush' the membrane surface, for 5 or 10 minutes. This works like the permeate rinse to some degree.
My current membrane (3 seasons on it) will start out doing 600 gph, with 2.5 conc, 7.5 perm.. After an hour or so, it settles in to 525-550 gph, with the perm flow slowing. After 4-6 hours I do the flush, repeating every hour or so. This will allow me do up 6000 gallons+ in a day. Occasionally I have to change my prefilter during these big days.
I typically run my PSI at 400, after the first 30 minutes or so.

My previous membrane had 7 seasons on it, and was starting at about 500, and would settle at 425. that's when I made the change.

[blissville maples]

That's an extremely odd electrical box. Usually the capacitor are held in place by a foam pad and maybe a clip. How did they hook up the cord? Has to be some lugs somewhere. Check and see if the wires get warm. Also you can run a load test on the current and see if it's within specs. A loose terminal will always create heat and/ or high amps. It will sometimes overheat and trip the breaker after a while.

Also the motor will not run without proper amperage. With that said your pump, unless you have a bad bearing and drawing high amp load, should always spin at the same rpm.

[Amber Gold]

The in/out wires come into the body of the box and connect to a set of lugs...female end of the connection. The cover side has the male end of the connection with a tab for each lug. The capacitor is also mounted to the cover. I should've taken pictures when I had it off, but didn't. I think a picture would help with the explanation.

I know enough about electricity to be somewhat dangerous. If it had a bad connection, it wouldn't be able to transfer 120V through the line, correct? So maybe it'd spin at the correct RPM, but not have the HP it should. And the HP is what's need to get the proper recirc flow rate?? Not sure, just trying to reason it out.

I was hoping to take the cover off, start it, and then test the connections, voltage readings, etc., but because the male side of the connecting lug is mounted to the cover, I can't do that. I have no idea how to test the motor to see if it's working properly.

[Amber Gold]

Thanks Jeff.

I'm putting about 2000 gal through it on the first pass, then send it through a second time. I generally freshen it up between passes. It's been taking 4-6 hrs to get through the first pass.