Advise on evaporator sizing

[flyswatterbanjo]

Hey Gang,

I recently joined the forum and have found a ridiculous amount of useful information! You all are a wealth of knowledge and a masters course in sugaring! THANK YOU!

Here's where I need your help: after this, my third season of boiling outdoors, in the wind and rain on a used 2 x 3 evaporator (boiled one season on concrete blocks and chaffing dishes) with 50 taps, I'm pulling the trigger on a sugarhouse, upgraded evaporator and more taps (on buckets… I'm committed to buckets).

But I'm finding the information from the various manufacturers a little hard to digest and I hope you all can shed some light on things.

What I'd like to know is:

1. 2x6 or 2x8? What is the minimum number of taps I could run on a 2x6 set-up vs. a 2 x 8? (Let's assume both would be wood fired without a blower or RO to start out with.)

2. What's a good pan arrangement (raised flue vs drop flue, cross flow pans, reverse flow etc) for starting out and sustaining a small operation (less than 500 taps) for a few years without feeling like I need to upgrade again? I'd rather add on to an existing set-up (with steamaways, RO etc) than start all over.

Alright, I know these questions are really broad but I'm just starting to plan for next season so I figured I needed to start the conversation some where.

Thanks!

[Russell Lampron]

For 300 taps or less a 2x6 is the way to go but if you are planning to start out at 300 or more go with the 2x8. I have the same 2x6 that I bought in 2000. I have added a hood and pre-heater and a blower to it and it does really well. I have never boiled with a drop flue but really like my raised flue. There are pro's and con's for both types but I feel that the ease of draining the flue pan and separate floats for both pans make the raised flue a better choice.

I added a 125gph RO when I hit 350 taps and am planning to upgrade to a 600gph RO for next season. I have 800 taps on vacuum now and plan on doubling that after I get the bigger RO.

[n8hutch]

It really all depends on how long you want to boil & how much money you want to spend. I have a full time Job 50 hrs a week. So I wanted to be able to boil some sap so I went with a bigger rig 30" x8' raised on 350 taps. It was none too big I can tell you that. If you go with a 2x8, I would get at least a 30" syrup pan maybe even a 3' syrup pan. Your evaporation rate might be a little lower but it will be easier to get a good gradient in the syrup pan & if you ever do go to reverse osmosis you will be glad you did.

[mellondome]

I started with my 2x6 raised flue with 45 buckets. Now with elapsed time and expansion, I am using the same 2x6 with over 1000 taps. Adding a preheater to get past 300 and the r/o to get to the current level (longest boil this year was 4 hours).

[BreezyHill]

I also have a 2x6 and an RO and will be shooting for 1200 next season and running higher sugar content from the RO to keep the boil time as reasonable as possible.

I will need to get a larger rig for our next expansion and future expansions as the next jump is another 350 and then it is another bush of 800 after that.

Ro is the work horse of our operation...and it is getting an expansion this summer to double its capacity.

IMO with no RO, you will be in the 30 gallon an hour rate so if you get 1.5 g per tap per day average, then for 8 hours of boil you can do 240 gallons so you are looking at around 160 taps but add a blower for air under the fire and you can get another 5-7 gallons per hour so over the 8 hr boil another 32 so nearly 200 taps. We did 240 back in 2011 on ours with AUF and a preheater and it sucked...boiled to 12pm-2 am nearly every night.
Now I usually only boil to 10 to 11 but when we had those three day nonstop runs I went to 2 am and still had more for the am to boil. Fire up the RO at 7 am, and then the evap, and run all day and quit when I would start to dose off.

For the money I would do a 2x8 as you can expand her even more with a steam away after the RO...or before depending on how your growth is planned out.

My thought process is that the steam away only works when the evap is running; but the RO, I can adjust and trip the auto run switch and walk away for several ours and be processing sap. Never seen a steam away do that.

Down the road I will add a steam away to increase my boiling efficiency.

On my rig I have to have 15 gallons in the evap feed tank when I shut down to keep her from boiling dry when she cools for the night. I just drop the floats to a minimal level and go to bed. if a float sticks open she wont burn or flood to bad.

Good Luck with that bucket addiction...as you age it will be easier to kick. I aged and now I throw a switch and the sap all comes to the sugar house in the vac lines...up hill & down hill it don't matter. The only buckets I touch now are full of syrup.

Great to see ya planning this out.

Good Luck!

Ben

[nymapleguy607]

If I had to do everything over again I would probably go with a 2x8 or a 2x10 evaporator. I ran 230 taps this year on high vac, and I will have around 350 next year. I have an Intensofire inspired arch underneath and a steamaway on top, I have a 4' standard flue pan and when everything is up and cranking I average about 72gph. This year with good vacuum I was getting over a gallon of sap per tap each day. Most of the time I would be boiling 4-6 hours each night, but since I'm adding taps I will be shopping for a small RO my goal is to boil about 4 hours each night. Best advice I would say is find out how much time you have to dedicate to boiling and then size the evaporator from there.

[Daryl]

I run a 2 x 6 1/2. It has a 30' cross flow syrup pan. The rig has under and over fir air and also a 4' preheater. The RO is a 375 gph Deer Run. We concentrate to 12-14%. The first pass takes the 1300 gallon tank down to the 400 gallon bulk tank then we go to the head tank and start the boil. Start to finish -cool- will be 4 - 5 hours and we have made 30+ gallons of syrup. I plan to upgrade the RO to a 500 gph. This should handle 1000+ taps on vac. with out a problem.

[MapleMark753]

The above thoughts and replies are by people maybe more experienced than me, and is good info.
I thought I'd just share our set up, for comparison. We use a Lapierre 2x5 raised flue, usually with a small RO (125 GPH), although sometimes without it. Its been adequate for our size. I think its advertised as being good for 50-250 taps. With the RO, we do more than that pretty easily. Something to consider anyway.
With a smaller raised or drop flue evaporator, from any manufacturer, an RO will give you options right out of the gate. If your budget would permit it, why not at least research a smaller sized RO paired with your new evaporator plans? We are glad we did, although it did cost more of course. So far I've not seen one person who was disappointed getting an RO. They may exist, but I haven't seen em.
You've already got 3 seasons under your belt, so have some good experience, get what works for you.
good luck!

[flyswatterbanjo]

Good Luck with that bucket addiction...as you age it will be easier to kick. I aged and now I throw a switch and the sap all comes to the sugar house in the vac lines...up hill & down hill it don't matter. The only buckets I touch now are full of syrup.



Thanks Ben! Great advise on the RO - I'll look at that first before I look at a steam away.

As for buckets, I've got three little kids who are just getting old enough to lift a half full bucket off a spout. Until they get too old to care, my helpers are built in!

[flyswatterbanjo]

The above thoughts and replies are by people maybe more experienced than me, and is good info.
I thought I'd just share our set up, for comparison. We use a Lapierre 2x5 raised flue, usually with a small RO (125 GPH), although sometimes without it. Its been adequate for our size. I think its advertised as being good for 50-250 taps. With the RO, we do more than that pretty easily. Something to consider anyway.
With a smaller raised or drop flue evaporator, from any manufacturer, an RO will give you options right out of the gate. If your budget would permit it, why not at least research a smaller sized RO paired with your new evaporator plans? We are glad we did, although it did cost more of course.

I think this year, with the plans for a sugarhouse (more on this in a later post) and a new evaporator, my marriage will only handle the two big purchases!

It does seem like the responses have endorsed the "small evaporator with add-ons for efficiency" approach. RO being the first add-on to invest in.

Thanks for your response!

[flyswatterbanjo]

Thanks for the advice, everyone. Here's what I've taken away so far:

1. Seems like folks are split between recommending the 2x6 vs the 2x8.

2. RO is the next thing to invest in for improving efficiency.

3. Plan the set-up by looking at how much time there is for boiling and work backwards from there.

Really great advice all around. Keep it coming!

[Shaun]

If I was to guess a 250 GPH RO puts out ~70 GPH 8%. Please correct me if I am wrong. It seems a 2.5x10 would be a great match for that. Sizing an evaporator on a single pass output of a maple RO may be something to consider? You would process a bunch of sap with that setup.

[Russell Lampron]

If I was to guess a 250 GPH RO puts out ~70 GPH 8%. Please correct me if I am wrong. It seems a 2.5x10 would be a great match for that. Sizing an evaporator on a single pass output of a maple RO may be something to consider? You would process a bunch of sap with that setup.

Your math is right Shaun. I have a 125 gph RO and when I single pass to 8% 35 gph is about what I was get. Boiling 8% is only fun until you start concentrating into the teens though. I don't start boiling until I hit 14% or higher now and I draw off 5 to 7 gallons of syrup in an hour with my 2x6. My preference is a small evaporator with a big RO. I plan to upgrade to a 600 gph RO for next season.

[mellondome]

If I was to guess a 250 GPH RO puts out ~70 GPH 8%. Please correct me if I am wrong. It seems a 2.5x10 would be a great match for that. Sizing an evaporator on a single pass output of a maple RO may be something to consider? You would process a bunch of sap with that setup.

Always remember that an ro can run even when you arent boiling.

Russell,
I went to a cdl600 this year from my single 4x40 home build. What a difference. And yes.. 8 is great to boil until you start going to 16..

[Russell Lampron]

Always remember that an ro can run even when you arent boiling.

Russell,
I went to a cdl600 this year from my single 4x40 home build. What a difference. And yes.. 8 is great to boil until you start going to 16..

It's fun to make 100 gallons of syrup with a cord of wood too!

[wiam]

Always remember that an ro can run even when you arent boiling.

Russell,
I went to a cdl600 this year from my single 4x40 home build. What a difference. And yes.. 8 is great to boil until you start going to 16..

And 16% is fun till you go to 18-20 lol. I have a 900 gph in front of my 2x6.

[Russell Lampron]

And 16% is fun till you go to 18-20 lol. I have a 900 gph in front of my 2x6.

Nice! That's what I like to see.

[Daryl]

I agree with both wiam and Russ. A bigger evaporator only burns a lot of fuel per gallon of syrup. The higher the concentrate on a small rig shortens the time of boiling. My 2 x 6 1/2 should be good for nearly 2000 taps and still keep the boiling at a reasonable amount of time.
Daryl

[BreezyHill]

Very correct on larger does burn more wood and smaller less; but there is a point with some designs that you are able to drop your stack temp with a longer flue pan.

The spreadsheet I made back in the winter to see how many taps we can handle in an 8 Hr boil on our 2x6 with our 40G/Hr B rate and 18% sugar, is 1920 and with a steam away added to the flue pan we can do 2987 taps on high vac. This was using the average run over the last three years. That being said the last two years have been pulling down the average slightly with the extreme cold and the frozen state of the trees. So next season when we have a normal winter we will be floating in sap...one can only hope.

This is using an 8 hr boil time and that gives me room to boil later on those all night runs and like this season when it ran for 3 days straight...well I will be getting 4-5 hours sleep and living in the sugar house the rest of the time.

This season we had nearly the same boiling hours on 750 taps as we had on 250 back in 2012 or was it 2011??? The further we get to getting the farm retubed the more efficient we have to get so that nobody gets burned out. I was getting close the end of this season but it was a matter of a few small machinery failures in a 48 hr window that is all part of the fun. Now we can look back and laugh but we have plans that will eliminate those issues in the future.

Nobody plans to fail...they just fail to plan.

I failed to factor in breaking the filter press and didn't have a plan to handle the finished syrup and then our keg supplier lost a shipment of kegs; but the sap didn't stop running, So we shipped some left over lower grade that we were not going to need for candy and got plastic for short term storage. We don't use plastic much any more since a friend sold me a keg and we packed of plastic and the keg out of the same batch last year. The taste difference was amazing.

Who has the most taps on a 2x6 rig? Net season we will have 1200 running an RO with 4 xle branes.

[Daryl]

My stack temps are 750 max. The fire box runs at 1625 -1700. I fire at 1450+. The flue pan is 4' long.
The probe tips are under the stack at the middle and near the top of the ramp on the raised flue rig.

[wiam]

Breezy I had 1700 this year and next year will be about 2400.

[BreezyHill]

Breezy I had 1700 this year and next year will be about 2400.

What membranes are in your RO and size

[wiam]

What membranes are in your RO and size

My Springtech has 2 8" xle's. They were 3 years old when I got it last fall. They did not flow great at the beginning of the season but I soap wash every day and let it sit overnight with soap and rinse in am. The performance improved over the season. Still do not do what they should but they did what I need. I'm thinking I will replace the first one with a MES for next year.