Hobby RO - Merlin take two

[Brent]

When I cleaned up the GE Merlin RO's after last year I discovered that the worst of the mess was the internal filter. In fact it was a carbon/charoal filter to remove chlorine from municipal water before it could damage the membranes.

This year I am using two external filters, one 5 micron and one 1 micron before the RO's this year.

This year I left the internal filters out of the system and fired them up with new membranes. They were removing 6 US gallons every 40 minutes so up to this point 10:20 PM ( and still boiling ) they have dumped over 100 gallons for neat clean water. At one point the sugar content was up just over 10% and there was none in the permeate according to the Misco Palm Abbe.

So tonight I will set up the second one and let them both go at it tomorrow.

We have one tote, 275 gallons, full and one near empty .. hopefully empty before I quit tonight, and I'm going to let the Merlin run all night transferring one to the other and see what the status is in the morning. Then I'll shut it down and start it flushing while I set up the second one.

Looks promising so far. The real deal will be in the morning.

[Gary R]

Brent, Good luck! I'm looking forward to hearing more.

[Brent]

Monday 8:00 AM
it froze up pretty good overnight 23 deg outside, and the Merlin's spec sheet notes that the performance will drop off significantly below 40 deg .. and it did. A loss of roughly 40% dropping temp from 80 deg to 50 deg and it running with 45 deg sap this morning. But in 7 hours of recirculating on the tote that started at 225 gallons is now 150 gallons. About a 75 gallon reduction in what I need to boil today. Pretty good for 25 cents worth of electricity. About a 2 hour time saving. The permeate still shows 0% and the Misco and the 150 gallons shows 4.2%

So the question is, is the reduction in flow that I see this morning because of the low temps or because the membranes are plugged. I'll have to wait for things to thaw and try a flush. The Merlin and pressure pump are in the sugar shack where the temp is just above 60 deg.

If time permits I plan to run a copper tube in the steam hood of the pre-heater to pre-heat the sap before it goes to the Merlin. It's top end temp limit is 100 deg.

[Greenthumb]

Brent I have been following this thread and the other one you had when you started your RO project very intensely. I think I have the basics to what’s involved in making a "homemade RO machine". I may start my own as getting the boil time down would do myself my family members and co workers a lot of good. This biggest question I have is where did you get your pump? I can’t seem to find one that would give the psi you have discussed. is there a online source store etc?

Thanks- I will continue to follow your information

[Brent]

I'm in the machine tool business ( not a great place to be these days ) and got the pump from one of our machine builders in Taiwan because the company that makes them, Walrus, also makes machine tool coolant pumps and they have been bulletproof.

GE wants the Merlin to have a "soft" pressurization start up and max at 80 PSI and the Walrus TQIC models do that perfectly. From memory I got it for about $ 700. The do have a distributor in the US but I don't know their prices.

http://www.walruspumps.com/products.html

From what I know of the Airablo and other Maple RO's this pressure is not close to high enough.

[Brent]

I took off the external filter, a 5 micron cartridge, cleaned it and backwashed it for a few minutes and put the system back together exactly as it was and the permeate flow looked like it returned to almost what it was yesterday.

Yippeeee

It looks like it was not a membrane problem last year, but a filter problem.

Now I thing I will put my syrup filter on in place of the cartridge filter, with its snap on 1 micron bags, which A) are cheaper per unit, B) I think will clean better than the wound cord cartridge, C) are 1 micron rather than 5 micron.

AND

I'll fire up the second Merlin and put it on line.

Big sap coming today around here.

EDIT Later the same day. The increased flow was short lived. I put in a new filter and that did not help much. Tonight, got to get the flushing cycle going.

[Brent]

Day 3 with the Magic Merlins

With only 1 running I figure it has dumped well over 200 gallons of water for me. That's a lot of boiling. Today I put in 1 micron filter in the GE 'whole house' filter. After a couple hours running it was obvious that it needed to be after the pump so it was pressurised ... it had been succing air into the system. Put the filter after the pump and put in the second Merlin. They transferred about 200 gallons of 2.4% sap to another tank in about 2 1/2 hours and bumped the sugar to 3%. The flow rate was great. The more I play with these the more convinced I am that pre-filtering will make or break an installation. Tonight I'll let them re-circulater in one tank. Hopeing to 4% on the whole tank before I quit for the night.

[Brent]

One more update: with both the Merlins going I am filling a 5 US gal pail in about 17 minutes.

The 2 x 6 evaporator is good for roughly 45 GPH so the Merlins are dumping about as much as I am boiling. That's half the time and half the fuel.

BUT

The Merlins can keep going when I'm not boiling, so I am guessing they will cut the boiling by 2/3.

Not bad for a $ 1700 system.
2 Merlins at $ 400 each
1 pump at about $ 800
1 filter at $ 100.
plus hoses etc.

[Greenthumb]

pics of that operation would be great for some of us visual learners. Sounds like a great project that I am following closley with my 1/2 pint going on some long burns. less time more syrup would be a great trade off.

[Brent]

Pictures are here

http://www.duffyslanemaple.ca/Merlin/RO-system.html

If you're on a Half Pint now, I would suggest you upgrade to a pan with flues before you mess with an RO
When I changed from a Hafl Pint to a 2 x 6 the boil rate went from about 8 GPH to 45 GPH

and

I did not burn any more wood. The fire box is the same and eats the same amount of wood.
You need the flues to increase the surface are to exchange the heat into the sap.

[Brent]

Wed AM comments

last night the permeate flow seemed to back off a bit, but I did not measure it.

Started up this morning and the flow was back to 5 US Gal in about 18 minutes. So far so good.

I am wondering if the "rest" during the night allowed the crud on the membranes to release and they
got flushed out when we restarted. ???

[maple sapper]

I would like to add a tid bit to Brents posts about his merlin project. I have built the exact same set up as Brent. I have run it once on a single merlin and once on a double. Lets just say, So far I am impressed. It has made a huge difference in my production. Heck, I even filled all the empty water bottles I had to use on my water cooler in my house. So not only am I helping by cutting boiling time, but I am saving $5 a bottle for drinking water. I am going to ask my relatives if they want some free filtered water. Its pretty much as organic as it gets. Maple sapper

[Greenthumb]

maple sapper I also would like to make a "homemade" ro machine and have been spending a lot of time following all who have used this ge merlin. I have several question from those that have tried it. I am trying to make sure I get the right pump can I buy a good jet pump / sump pump and do it? Should a uv light be added to the concentraded sap. what prefilters are you using, did you just use the factory supplied filters that came with the merlin etc. any info you have that I could pick your brain would be great. I am hoping that I can get this going for next year as our season is just about over in southern Michigan.

[Brent]

Well were into the season and after several days running the Merlins am more and more convinced that the problems I had last year were the builtin carbon/charcoal filters.

Running them this year with an external "whole house filter" and a 1 micron wound media from TSC there has been no drop off in performance. It does cycle up and down a bit according to temperature. At start up this morning I was filling the 5 gallon pail in about 20-25 minutes ( I got distracted ) which is still pretty good considering the temperature was about 35. The buckets beside the test buckets still had ice on top.

Maple Sapper is trying it as noted above. He is moving his system inside at night and flushing it with fresh water. There could be some benefit in doing this to prevent the microbes from growing into the membrane itself. Time will tell.

I am almost confident enough to recommend this system now.

8:00 PM Thursday. Ran it recirculating most of the afternoon. It was real cold. Sugar content 4.9% and about 150 gallons waiting for me to light the fire in the morning.

[3% Solution]

Brent,
You've caught my eye here!!!!
Would like to know more.
What size pump, is your RO area heated, stuff like that.
Keep the info coming.
Thanks!!

Dave

[Brent]

Saturday Morning Update:
The Merlins ran most of the day yesterday and I think I started to notice a pattern. At times the flow of permeate was great and then would taper off.
Certainly the colder the sap the more it hurts performance but it also seems to be related to the sugar content.

By late afternoon we had 150 gallons of 5.1% and the permeate flow was pretty poor. Then my wife started bringing in the new collections and I switched from recirculating to process the new stuff that had just come in at about 2.2%. The permeate flow immediately jumped back up to 5 gallons every 20 minutes or so. It had slowed down to 5 gallons every 40-45 minutes.

Gregg, keep and eye on your operations to see if you see the same pattern.

11:00 AM Sunday. The tote that was full at 275 gallons last night a 1:00AM when I quit is now at 170. A bit over 100 gallons dumped while I slept. I'm likeing this poor man's RO more and more.

If I could find the time to put some copper pipe in the preheater hood so it processed warm sap it would do even better. But that has to be done more or less as we boil because you can't warm it and leave it sit around.

[Brent]

Dave: I got my pump directly from connections in Taiwan.

Gregg (aka Maple Sapper ) got the same pump from their distribution co. in California.

http://www.walruspumps.com/products.html
The model is the TQIC 1 Hp.
Mine cost about $800. Don't know what the US price is.

I selected this pump because we use some of their other products on our CNC machines and trust them. Secondly they are automatic pressure compensating through a built in pressure sensor and inverter drive. Third GE state that they want a soft start pressurisation on the Merlins. The 1 Hp model perfectly matches the pressure and flow to run 2 of the Merlins.

The only issue, which is common to most higher pressure pumps, is they they're a bitch to prime. You really need the pump below your tank level.

[maple sapper]

To all merlin followers,

I have the same experience around 5-6% it slows. A good run for me is approx 150 gals. By the time I start the merlins, and then get the fire going there is obvious drop in sap level. So running the merlins while boiling when I get to about 35-40 gals I shut it down cause its obvious that the merlins are going to run it down to nothing. I have measured 5-6% at that point. At that time I take them in one at a time to flush them for the next go around. I rigged up a tempering valve on my laundry hook up. It is set to 100 deg. Far. exactly. I let it run for a while and check for sugars on the brine side and has come up with none a few times in a row. So then flush the next one with warm water and let them sit over night with water in them then flush one last time to make sure there is no stray sugars that have come loose with sitting water.

as far as the pump goes I unthread the plug on top and use a lateral hose form taps on a tiny funnel to fill chamber for priming. My overhead tank is above my pump so gravity does a good job bringing a constant flow of sap.

[maple sapper]

My pump cost me almost $1400 with freight and duties. Its well worth it though. Nice digital display and all stainless. I would not doubt if the lines were sized properly that the pump would handle 4 of the merlins. It has a 1" port.

[Brent]

Sunday, after running the Merlins just over 12 hours overnight and reducing the tote of 275 gallons down to less than half, and getting the sugar up to about 5%, we started boiling, and for the first time ever, made about 8 gallons of medium syrup. Only ever had light or extra light till yesterday.

I am suspecting, but not very sure, that having put maybe 40 hours on the 1 micron prefilter, that it has become a breeding ground for the microbes.
Tonight going to replace that and see if we get lighter syrup.

Following Gregg's example, last night I took the Merlins inside and ran warm water through them and again demonstrated the significance of temperature on the membranes. I did not measure it by just eyeballing the flow rates, I think we get 3 times the permeate up near 90 deg that we do at normal sap temp. Got to get the copper tubes going through the hood to preheat the sap before the it hits the Merlins.
Much happier with the overall results this year than last, and I am more and more convinced the problem last year was the filter in the top champer of of the Merlin, which I have left out completely this year.

[maple sapper]

Brent,

Dont be so disappointed. I have only made b, ever. One small batch of med. a on a turkey fryer. But, now with the ro and a few pan mods, we have lighter working its way down the channels and a few more draws and we shall see what we are getting. This is of course due to the RO. Thank you again.

[Brent]

I have had a number of enquiries about the pump I'm using with the Merlin's and hope I don't get myself in trouble with the forum monitors, but if there are a few guys out there that are interested, I would be willing to bring in a few more with our next machines. Should be able to save $500 to $ 600 from the California price.

[Brent]

This may be the last update for the year. Getting too warm tonight and tomorrow.

Learned enough about the Merlins to be pretty confident in them now. Last night at 10:00 when I quit, I put them to work on tote that had about 260 US gallons in it at 2.4% By this morning when I started boiling they had cut it down to about 125 gallons that measured 4.9% The permeate was still 0.0 and the flow had slowed down. But the flow was great last night. The sap was pretty cold. We did have a frost but not enough to cause problems. The Merlins are in the sugar shack with a bit of heat and the tank was outside.

The external 1 micron filter started to plug up after about 40 hours. There was a 3 to 5 psi pressure drop behind the filter so I just bumped up the settng on the pump to max and the pressure gauges on the Merlins both read 80 psi, which is optimum for them.

A fresh filter and away we went again. The filter I took out was a little off color, like light rust, and it smelled a little foul. So it seems 40 hours above freezing and there are enough microbes to plug it and it needs changing.

We've put nearlyt 3,000 US gallons through the Merlins. Much of that went through more than once when we recycled at night, which was almost every night. Our boiling could not have kept up with that much without the Merlins

Next year, if the economy does to collapse, I plan to put a UV light in to treat all the sap as it comes from the bush and before it goes into the holding tanks.

Much happier this year than last. All the syrup tastes great.