Dow LP-4040 membranes

[Brent]

I have been crawling the DOW web site and found on the specs page for the XLE-4040 membranes there is a reference to the LP-4040 membranes.

The only comment that differentiates the two is that the LP-4040 is best suited for feed stocks of low temperature, and that's pretty much our sap.

Anyone out there tried one of these yet ????

[danno]

If nobody knows, give Joe from Atlantic a call. Great guy to talk to.

[Brent]

Danno I've been emailing back and forth with Joe but I have not spoken to him yet. I just got a pair of XLE-4040's from him.

So I start looking through the Dow web site and got good cleaning instructions, but in the process found the LP-4040 were in the same category as XLE-4040, but Dow comments that they are better at low temperature feeds ... like we get in maple sap. I've asked Joe about them but
he says we need to talk. I'll do that tomorrow.

But Joe sends me another bunch of documents and specs and one of them details the most common causes of membrane failure. In the list of causes is "over pressure" and is emphasizes that the XLE-4040 should not be run at over 150 psi. The Dow web site specs say 600 psi maximum. There's a bit of contradiction here. I think that will come as a surprise to a lot of XLE users. The document does not have an official Dow doc number on it and it makes no references to use as a sap concentrator, so I don't know yet where the document came from. Hopefully I'll find out tomorrow.

One other surprise that came off the Dow web site cleaning instructions was the huge increase in washing effectiveness as alkalinity increases. They have a graph of "relative change in permeate flow" in the vertical axis and Ph on the horizontal axis. at Ph 10 they rank flow change at about 1. At Ph 11 they rank the flow change at 2. But at Ph 13 they rank the flow change at 17 !!!!!!! Boy if we want good cleaning we've really got to be on top of this.

I've put this document on our web site. The link is at the bottom of the page
http://www.duffyslanemaple.ca/syrup-equipment/syrup-equip.html

[danno]

Hi Brent - the cleaning instructions are very helpful. Not sure how I'm going to get my rinse up to 68 f, imersion heater?

I just got XLE's from Joe recently and was looking for cleaning instructions - so thank you.

Did you happen to see operating instructions? If so, please add those to your site as well. Nice site by the way - lots of shiny SS.

[Brent]

Danno

The Airablo RO generates enough turbulance in the plumbing that all I need to do is run it for about 45 minutes and the temps run up by themselves. This is what the instructions say to do. I guess it's also a sign of excessive resistance in the plumbing. Choke points on the flow, right angle fittings instead of elbows.

I'll browse what I've downloaded to see if there's anything useful. Most of what I have came from the DOW site. Navigating is not totaly instinctive. Poke around and you'll find most of it.
Here's a starting point
http://www.dowwaterandprocess.com/products/ronf.htm

One thing that did surprise me is that the XLE-4040 is a reverse osmosis membrane ... not a nanofiltration membrane. The folks in Quebec never got their study on line in English. It would have been interesting to see what they got from their tests. I did glean from the papers that most nanofiltration membranes pass some minerals, potasium being one, and their taste testers found it noticable enough to down rate the syrup.

[Brent]

On the same page of our website I have now added a link
to the Dow recommended startup proceedure. On the same page noted above.

All of the membrane startup proceedures I have read, including those from GE, has strongly suggested a soft built up of pressure, in this case over 30 to 60 seconds.

The high pressure pump on my rig whacks the pressure up instantaneously. I'm wondering if we should be using an inverter to create a slow rev up to full rpm.

[WMF]

With only one membrane per housing its not a problem.
Most commercial RO's have as many as six membranes per housing stacked end to end. This puts tremendous force on the last membrane in the stack if there are some gaps between each element at startup.

Did you find out any more info on why they recommend a max of 150 psi for the XLE 4040 on sap ?

[Brent]

With only one membrane per housing its not a problem.
Most commercial RO's have as many as six membranes per housing stacked end to end. This puts tremendous force on the last membrane in the stack if there are some gaps between each element at startup.

Did you find out any more info on why they recommend a max of 150 psi for the XLE 4040 on sap ?

Joe never did say who authored the 'why membranes fail'
document. I got the impression that the 600 PSI spec was written to meet industry standard comparisons only.
In practice, they should be run much lower. Joe suggest I try 200 - 250. From some of my industrial filtering experiencem,
higher pressure forces debris to impact on the media harder, making it harder to remove. So it's a trade off. Lower pressure, lower flows
and better cleaning. High pressure, higher flows, more difficult cleaning and maybe lower flows anyway.

Dow specifically says that membranes should not be put in series. They should run parallel. This makes sense to me. So yesterday I beat myself up trying to figure the flows on the Airablo RO. Nothing is labelled IN or OUT, HI or LOW pressure feed, or RECIRCULATE. In fact the entire high pressure flow is through the first membrane then into the second. It doesn't seem right to me, but what do I know, I only mapped the flow last night.

[Brent]

With only one membrane per housing its not a problem.
Most commercial RO's have as many as six membranes per housing stacked end to end. This puts tremendous force on the last membrane in the stack if there are some gaps between each element at startup.


I don't follow your logic on this. If the motor hits full speed in 2/10 of a second and there is nothing compressable in the system, they hydaulic shock has to result. Other than a soft start inverter motor, I guess you could put a air chamber in the system on a T between the high pressure output and the membrane vessel. You can buy miniature versions of these at Home Depot to stop pipe banging in you household plumbing.

[PATheron]

I think that all of the maple ro machines as far as I can see run the membranes in series. I know both my old machine and the newer one are hooked in series. Wonder if they do things differently with the membranes in a water purifier type setup? Anyway my nf-270's are in series. I only run them in my older machine at 300 psi. Theron

[Brent]

For more than you ever wanted to know, this page on the DOW site has a complete technical manual. All 180 odd pages of it.

http://www.dowwaterandprocess.com/support_training/literature_manuals/prod_manuals.htm

Of interest is the temperature correction factor. Joe sent me one and there is another burried in the above manual.
Joe's table goes down to 41 deg F. at which point the correction factor is 2.58

So the XLE-4040 with a rating of 2600 gallons per day would drop to 2600 / 2.58 = 1007 gallons per day or 42 gallons per hour running at 100 psi. This is a salt water calculation.

Our cold sap is really beating up the RO performance. I found this was about the same ratio when I ran the little GE Merlins for a couple years.

If we could put the sap through our steam and pre-heat it to 77 degrees, theoretically we would get about 2 1/2 times the throughput.

hmmmmm..........

[802maple]

Warming the sap will make them process more but you need to be able to boil the sap as soon as you run it thru the RO or you will get tremendous bacteria growth in a hurry.

[mapleack]

I've been wondering about the temperature to flow relationship too. If you had a steamaway and put the condensate through a plate heat exchanger before the RO to preheat raw sap, then matched the RO out put right to the evaporator, you might get alot more RO capacity for your money. A UV light could even be put before the RO to help cut down on bacteria in the RO. Somebody try it and let us know! :)

[shane hickey]

I trying to do that this year to see how it works to make boiling go faster, sap will go through the ro then a 5x16 evaporator that has a piggy back unit
which will be like a large pre heater it will draw off from the finish pan, then go to a paddle pump to a 6x20 evaporator. From there it will be drawed off the 6x20 into a 40 gallon steem tup that is hooked to 2 filter press's. From there goes to barrells. I hope that there will almost be a steady stream of syrup the whole time we are boiling to make the nights go faster. I'll have 3 people help boiling, I just hope that I dont have any syrup in flu pan, I'll have to keep a real good eye on things for the first couple of boils, and also when we witch sides. I'll keep you guys informed and let you know how things go.

shane

[mapleack]

I trying to do that this year to see how it works to make boiling go faster, sap will go through the ro then a 5x16 evaporator that has a piggy back unit
which will be like a large pre heater it will draw off from the finish pan, then go to a paddle pump to a 6x20 evaporator. From there it will be drawed off the 6x20 into a 40 gallon steem tup that is hooked to 2 filter press's. From there goes to barrells. I hope that there will almost be a steady stream of syrup the whole time we are boiling to make the nights go faster. I'll have 3 people help boiling, I just hope that I dont have any syrup in flu pan, I'll have to keep a real good eye on things for the first couple of boils, and also when we witch sides. I'll keep you guys informed and let you know how things go.

shane

Shane, that sounds very impressive and very scary all at the same time. Are these rigs wood fired or oil? Pictures would be appreciated greatly by all I'm sure!

[shane hickey]

Both evaporators are wood fired I've used to evaporators before but this year I added the Ro. No one around my area has one and I had never seen one work before so it will be new to me. It kind of scares me to for the first time I will have to keep a close attention to things. How do you post pictures? I have tried but they all say that there are to many kb and wont upload.

[mapleack]

Pictures are limited to a certain file size on here, probably 800x600 dimensions. You could also start a photobucket account and put the link in your signature like mine.

[vtmaplemaker]

you will be way overkill with the two evaps, and a ro on 10k taps... I am not sure what size ro u baut, but in my oppinion you will be bettwr off concentrating to say 16% with the ro, then boiling to finish syrup on the 5x16 at a rate of close to 50 gal of finised syrup a hour... with the 2 evaps, set up the way you are talking and a ro in front, you will have syrup before it even hits the second evap, unless you have 4" lines and floats connecting it all...

[802maple]

vtmaplemaker, my thoughts exactly

[shane hickey]

I just want to try it. I figured it was over kill but I'm picking up woods all the time this is my third year in maple syrup and I'm 27 At this rate I might have 20k taps in five years ( if only in my dreams) I'm always thinking of doing things bigger and better maple syrup and farming is my living so it's either go big or frind a dead end job.
shane

[vtmaplemaker]

my first thaut was how do you filter syrup that fast, then I realized thats not a problem... alls you need to do is find a way to shovel the candy from the last evaporator that fast...

alls I can see out of this, is black smoke from the pans, and a very bad smell in my nose

[Brent]

It's too late to put a new set of pans on order for delivery this season. Just run one. If you've never heard of anyone else doing this, chances are it's not a good science experiment.

[shane hickey]

how can I put pictures on here I looked every where, photobucket was a good one but they wanted a credit card before you could set up a photo site
shane

[PATheron]

Shane- What did you buy for an ro? Theron

[shane hickey]

I bought a this unit from my neighbor never used one and never seen one used all I can tell you is that he bought new membranes from sugarbush supplies and the squeeze pump says tanaka on the side I will try to send a picture please let me know if you can see it, I'm really having a hard time attaching picture

shane2154

[PATheron]

Looks pretty serious. Must be a large older model? Did he give you an idea of the gph?

[shane hickey]

I said 2000 gallons an hour it has 2/3 phase motor one for the squeeze pump and another for the recirculation pump21552156

[PATheron]

How many membranes is it? Other thing is it has to have a feed pump, high pressure pump, and may or may not have a recirc pump. If it only has two pumps maybe a sap feed and a high pressure and no recirc? See how many horse power the high pressure pump is and how many membranes it has and that will give you a good idea of the size. Theron

[PATheron]

The pics are awesome. It looks like your going to something big one way or another. The smaller rig is pretty nice and the long one is unique for sure. Theron

[vtmaplemaker]

where would one find enough imigrant workers to fire and lug all that wood?? I could use some of this help for my woods...

[shane hickey]

How many membranes is it? Other thing is it has to have a feed pump, high pressure pump, and may or may not have a recirc pump. If it only has two pumps maybe a sap feed and a high pressure and no recirc? See how many horse power the high pressure pump is and how many membranes it has and that will give you a good idea of the size. Theron


Patheron the largest motor is 15 hp and the second is a 10 hp He thought that needed a recirculation pump because the vane pump would run dry I thought it had 3 membranes but the cases that it came in had 6 membranes that are in the basement in soluion, the squeeze pump is "I think High pressure" the guage goes to 45 to 480 psi. There is also a liquid cooler on it but I was going to bypass it if I could, My plans are to hook my 6x20 to it and use my 5x16 when we start getting 10,000 gallons of sap a day

[gmcooper]

Shane nice pics. Incredible set up. I think the understatement of the year might be " I'll have to keep a real good eye on things for the first couple of boils, ". I like the go big or go home theory but I think in this case you potentially have the largest maple ash production facility in USA. Maybe 802Maple (Jerry) can help out.
Hoping all goes well for you!
Mark

[PATheron]

I dont know what to think. Sounds like it was a real big unit. Do you have 3 phase to run the motors? I still dont understand what was used as a feed pump to feed the unit. Thats a lot of ro. If you get that working anywhere near right I doubt youll need two evaps but whatever youve got them all hooked up. Try to focus your efforts on making that ro work right. That will be way easier than running evaps. My little 600 gph ro will dump 300 gallons of water per hour indefenitely. I dont even have to be home to do it. That will probly match right there one of those evaps. Thats with just one eight inch post. Just for perspective. Theron

[PATheron]

Im loving the guys style. I just hope he gets a handle on that ro if he really drills 10,000 holes. Whatever works, The shed and the setup of the evaps and the evaps are really great looking. Theron

[shane hickey]

Thanks mark, my dad was real big with 14000 taps and I was only 8 years old when he sold everything and cleared cut the woods all I can remeber is alot of yelling because the lack of sleep be got and 20 to 25 guys gathering buckets he only had 2 woods on tubing, He said he wanted nothing to do with it when I got started, but he seems to always be there when I'm boiling. He sure does like to watch but he will not pick up 1 stick of wood.
He used natural gas and I use roughly 175 to 200 cords of wood which the guys cut during the summer.

[Amber Gold]

I've been reading this post and it's pretty interesting...I almost fell over in my chair when I read 200 cords of wood. I know a producer with 6-7k taps w/ a 5x14 and a 600 gph RO and he boils for 5hrs per night...guessing on that, but it's not much.

[shane hickey]

I do have three phase power I just never seen an ro work before and never used it he only bought the membranes, It came out fo kelloggs ceral plant in battle creek Mi he works there and got the first chance to buy it. I guess it processed the sugar in the sugar water for the ceral.2158

[tuckermtn]

it seems like with that much pump HP you would run more membranes that the 6 that are with it. It looks like from the picts there are two membrane vessels (3 membranes in each vessel) For comparison, the RO that Parker just got has a 10hp tanakaflo pump, no recirc pump and there are something like 14 membranes in 7 vessels.

I think Parkers plan was to only run about half of the membranes and recirc under low pressure...

[shane hickey]

Hey Josh, In season i have 8 guys that work for me we start at 7 am collecting sap, it takes us all day to collect because our woods are up to 15 miles radius, by the time we get home custome boilers are there waiting for us to drop off the sap. Then it is time to start the evaporators, i quit boiling at 5am, get two hours of sleep and i am back at it at 7am. Its more of a job then a hobby for me but the money is really good.

shane

[shane hickey]

eric, my computer took a crap, so it's taking a long to through treads, how many gallons an hour will his do? Do you know if it will shut off if it looses prime?

[Brent]

Getting back to the question of DOW LP-4040 membranes

After a few emails with folks at Dow, nobody would say why one spec says it is better at low temps and nobody would say better than what other membrane at low temps.

The key seems to be to expect 3% reduction in perforance for every 1 deg C drop below 25. So we should expect a drop of 50 to 75% ..... before we get a build up of crud.

And about warming the sap ... keep in mind that the max operating temp of most membranes is about 115 to 120 degrees. Check the specs on yours before going down this road too far. This is why the cut off temp for cleaning is pre-set.

[whalems]

Shane is that 175-200 Full cords or face cords?

[dschultz]

Whalems,that has to be full cord, because on mine in a good year I put 75 full cord through my rig

[danno]

Brent - thanks for the additional info. Let's keep this thread going in season so we can compare notes on best operating pressures and cleaning procedures for these membranes.

[shane hickey]

Yes full cords, all this wood makes the place look like a mess, I have natural gas but, I was told it would cost 7 for a gallon of syrup so that would be 15 to 18 thousand dollars alone shane

[whalems]

Are there any standing non maple trees standing in Vermontville??:lol:

[Thad Blaisdell]

Shane, I too have 3 phase power in my sugarhouse. I am running a 1200 gal per hour RO, I would think you will be fine with what you are talking about. As far as burning wood..... with the RO you will cut everything down on the usage end. I burn oil I plan on using .6 gallons of oil to make a gallon of syrup. At 4000 gallons I will burn 2400 gallons of oil roughly $7500 in oil. I do all of this by myself as I do not have to gather like you. As far as boil time.... you are going to see a huge reduction in that. I use a 6x14 and plan to make 60 gallons of syrup an hour. I have a friend with a 5x14 who makes 45 gallons per hour. He runs the RO much heavier than I do. Good Luck with the RO