Flow Rates on a Deer Run 125

[SeanD]

This will be my third season on a Deer Run 125. Aside from the quick how-to Ray gave me and the great manual Maple Flats put together, I just kind of run it the way that seems right. I'm curious how others run theirs as a comparison.

I typically start it up and start tightening the high pressure valve until it reaches about 255 psi or so. Then I begin opening the recirculation needle valve and simultaneously, slowly tightening the high pressure valve - keeping the pressure right around 255 psi. I've found that if I go higher than that, the pressure spikes quickly and the high pressure cut off shuts it all down and I have to start all over. The high pressure seems to cut off around 275 psi rather than the 295 that the manual says. Either that or the needle rockets up before I can see it. I'm wondering if that's typical for others.

For the first 10 minutes or so, the pressure slowly climbs and I have to slowly continue opening the recirculation needle valve to keep it at 255. In the next ten minutes, I have to do it a little less. In the next hour, even less. I'll keep an eye on it and tweak as needed, but it usually sits right around 255-260 the rest of the way.

By this point, after all the tweaks and evening things out, the flow rates are around 1.0 gpm on the permeate and .5 or .6 on the concentrate. That gives me about 90 gph and takes my 2.0-2.5% sap to 6.0-7.0% concentrate. I have only done single passes.

The 90ish gph works for me and I get a lot done while I'm waiting for the concentrate. At this rate though, I try to get most of the way through the raw sap before lighting the fire. At .5 gpm for concentrate, my evaporator can actually outrun the RO. The upside, is I'm squeezing a lot of water out of the sap on one pass.

How does this jibe with how others use their Deer Run? I've always wondered if there's something less than ideal about my settings.

Sean

[minehart gap]

Sean, I have only had mine for this season but have been experiencing some of the same. I suspected that I just needed to do a backwash but I believe that I will re-circulate the 110 degree water through it for 10 minutes first so that it dissolves the sugar out then flush 125 or so gallon of permeate.

I also use mapleflats manual, your right in calling it great. What I described about isn't necessarily in Dave's manual, but I am assuming that before I do a backwash I want the sugar out of the membrane by using some hot water.

I hope you get some clarity and tricks others have come up with.

[mol1jb]

This is my first season in the 125 hobby (no bells or whistles unit) and I have only used it once. I really appreciate you detailing your results so I can get an idea of what I should shoot for. This is the first RO unit I have used and am in love with the time it saves.

[MapleMark753]

We have had several years now on our 125, and its worked well. In short we've experienced similar operating scenarios as you mention, with only a couple of differences. The high pressure trip switch has never tripped the machine off for us, and we will go above 275, but under 295 regularly. I THINK the high pressure cutoff switch is an adjustable one (never adjusted ours though) and it sounds as though yours MAY be set just a tad lower? Again I just say that because during normal operation of ours it regularly (but not always) ends up a bit higher than the 275 that you mention. Also we may not concentrate as high as you do and I think we get a bit (not much but a bit) more flow on both concentrate and permeate outflow.
Like you, we adjust both the main pressure valve and the recirculation valve until its nearly stable for quite a good period of time. I mean pressure still rises slightly over time at what I'm calling "stable" but its nothing like the first several minutes. I know it is not, but I still smile and think its magic sometimes... take care, Mark

[minehart gap]

Mark, would you please describe your rinse/back flush/wash routine or schedule

[maple flats]

A few points, you can adjust the trip point on the high pressure. It should be set at or near 300 psi. Open the cover on it and turn the adjustment screw and get it to between 295 and 300 psi. (I had to adjust mine, it was about 310 psi when I got it, I turned it down. Mine now trips at 298-302.) That is unless the newer ro's are not adjustable. You need to realize that my RO is serial # 35.
If you add the numbers you are getting I see about 90 gph, that sounds low. One thing that lowers the total is the bypass for recirculation. Maybe you are opening that too much, but in the process you are getting fewer gallons total but at slightly higher removal rate.
When I operate, I start at 270-275 PSI, then I open the recirc valve but only about 1/4 turn, then I crank the main T valve to return the pressure to original. If I open recirc. any more, it is only slight, less than another 1/4 turn. From there I do all pressure adjustments using the main T handle pressure valve. By recirculating more every time the pressure rises you are lowering the total. If your sap is at 37 degrees you should be getting a flow of 120-130 gph. Try on a 125 to work towards that. You will in the end, get better performance. You may also want to try running thru a second time, from the head tank at the draw off end thru the RO and back to the opposite end of the head tank. The second pass will work best if you back the pressure off to about 240-250. I often do that.
My manual... AQs I stated in the past, I first typed the manual just from reading Ray's manual sentence by sentence, re-wording it so I understood it and then typed it. From there I have had several changes, mostly as someone asks a question that does not seem to be answered in the old version. I then typed an answer to answer that question or point. Finally, in my later versions I added a section at the end, telling how I now use it. I did run it by Ray, but I wrote the proceedure.
Good luck all, and by the way, if anyone wants the newest version. My latest version was update 11/6/18. If you have one from before that, send an email to: dave@cnymaple.com requesting the RO manual.

[SeanD]

If you add the numbers you are getting I see about 90 gph, that sounds low. One thing that lowers the total is the bypass for recirculation. Maybe you are opening that too much, but in the process you are getting fewer gallons total but at slightly higher removal rate.
When I operate, I start at 270-275 PSI, then I open the recirc valve but only about 1/4 turn, then I crank the main T valve to return the pressure to original. If I open recirc. any more, it is only slight, less than another 1/4 turn. From there I do all pressure adjustments using the main T handle pressure valve. By recirculating more every time the pressure rises you are lowering the total. If your sap is at 37 degrees you should be getting a flow of 120-130 gph. Try on a 125 to work towards that. You will in the end, get better performance. You may also want to try running thru a second time, from the head tank at the draw off end thru the RO and back to the opposite end of the head tank. The second pass will work best if you back the pressure off to about 240-250. I often do that.

I had a feeling. That's pretty much what's happening. I'm using the recirculation valve to adjust downward as the pressure climbs. I'll often be 1.5 to 1.75 turns on the recirculation by the time things are done. The upside has been sweeter concentrate.

I'm going to adjust the high pressure switch upward. Can I do that while it's running or should I only make adjustments when it's off and just try again and again until I hit the target? I have to flush the RO for the season, so I'll try during the rinse after the soap wash.

I can tell the high amount of recirculation is lowering my flow rates, but what will happen when I start running at 270-275 psi (from the 255 I'm at)? I guess I won't need to recirculate as much which will increase my flow rate and save time, but what effect does the higher psi have on sugar content?

Thanks for the input.

[maple flats]

I suggest you have it off, make a little adjustment then try it. To test just run the RO, with the recirculation closed, then very slowly increase the pressure and watch for when the pressure trips it. At least that's how I did it.

[maple flats]

I think you will get more concentrate at a higher % faster with less recirculation and run 2 passes, at least that has been my experience with my Deer Run 250.

[MapleMark753]

I like that you're getting 6 to 7 percent concentrate on the one pass through. 5 or 6 is more normal for me. Your percent concentrate suggests you're doing a lot right as long as it doesn't clog up on you. We do a cold water rinse, hot permeate wash (no soap), let that sit for 30 minutes or so, and then another cold water rinse right after we finish concentrating for the day during the season. A quick cold water rinse and a new filter and its ready to go the next day. Soap wash less frequently during the season. I too have done one pass before boiling, and we finish concentrating before lighting the fire. Not as efficient maybe but I've got a better feeling doing it that way. We could start the evaporator about half way through concentrating but just haven't done it that way yet.
Just an aside, I too have felt the "am I doing something wrong" anxiety many many times during operation due to the several adjustments on both the high pressure valve and the recirculation valve. But, it keeps on working, doing well, and nothings busted (yet anyways!).
take care, Mark

[SeanD]

I wanted to give you all a big thank you for your input. I was able to adjust the high pressure switch very simply. It's a basic knob that can be turned with fingertips. I had to see-saw back and forth, but I got it set to 195 psi, now.

What a difference cranking this thing at 175 psi!! I tried all different settings and ended up very happy with the concentrate at 1.1 and the permeate at 1.2. That gave me a great rate and brought my 2% up to 5%. I was a little nervous about trying the second pass, so I stupidly put in a 7 hour boil yesterday. For today's run, I didn't make that mistake.

Today's rates were very similar on the first pass - concentrate 1.0 and permeate at 1.2 (at 175 psi). Then for the second pass, the rates were still really good. Dave, I know you run yours at lower pressure, but I wanted to see what it could do. I ended up back at 270/275 and squeezing more out of it. The concentrate was at 1.05 and the permeate was at .8. That got me to 8%.

I quickly got enough to light the fire, so I figured, what the heck and tightened it up more. I held at 270, but recirculated more so the concentrate dropped to .6 and the permeate dropped to .7 (kind of what I had last year on a first pass). That got it to 9% and the RO still finished way ahead of my boil. The rates never budged.

I'm so happy I'm maximizing the benefits of the RO. Thanks again for your help!