Making a new evaporator

[Fleman202]

Hey guys,

2015 will be my second season and i am totally hooked after getting ten gallons my first year. I am planning on building a much improved evaporator this winter. I have and will continue to look through what has already been said but still want to put ask a couple questions.

What are the most important things to consider and make sure are a part of an evaporator/arch?
Are blowers really necessary? it looks they are...
Drop flue or raised flue?
Good preheating system?

I will have I am guessing 150 or so taps probably on buckets. Is there a huge advantage besides labor time to putting a portion of those taps on a gravity or vac line? Will I get a lot of volume difference using buckets?

[psparr]

A preheater would help out a good bit. A flue pan would be great. I use a squirrel cage fan in front of my ash door that works fine for me.

If you have the slope, 3/16 gravity tubing is amazing. Your getting free vacuum. I ran two runs last year for the first time and was really impressed.

Good luckn

Sent from my SPH-L710 using Forum Fiend v1.2.7.

[BreezyHill]

Preheater and blowers are big energy savers. The blower will be a time saver also, as you will get a hotter fire. Think of the old blacksmiths...coal forge with a billows to pump up the fire to get that section of iron red hot.

I prefer raised flue so that I don't need to worry about people loading the fire , hitting the flues as much.

Tubing is a life saver! When we started in 1971 we ran buckets for two seasons. If it weren't so much fun the work of buckets would have killed it.

Tubing on vac will increase production 150% at 16" of vacuum and for every inch of mercury above 16" you increase production by 5-7%. The study by Steve Childs (Cornell) logged just over 10 gallons sap on gravity and 15.6 more gallons for the trees that were on 16" of vacuum; for about 26.8 gallons per tap of sap.

So if you figure 150 taps at 10 gallons that is 1500 gallons of sap to boil for a season. As a kid I recall having buckets over flowing when dumping 2x daily. In that scenario you are looking at 300 gallons to boil. With vacuum you would be looking at as much as 450 gallons to boil.

I have a 2x6 with a preheater & Forced draft(AUF) and at boiling in the low 30's per hour that isn't to bad if you get an early start. I have had to boil for 18 hours a day for 5 days at a time...that gets old fast.

So as to not burn your self or wife out I would put in tubing and add vacuum next season. BUT if you are looking to grow fast tube it and put on vac. I run old dairy pumps and can get 28"+. Last season was to cold in our bush for a good season; but season before we did .5 g of syrup/ tap.

Market for product is also important and that is why we are trying to get the remainder of the farm tubed to get back to 1500+. Plans for further expansion in the works. We do have an RO and that keeps the wife happy as she hates me waking her up when I am done for the night.

We will be adding Air Over Fire to get more from our fuel source but there is little to no smoke out the stack.

Tig welded pans are much nicer than the silver soldered pans. If boiling long hours a temp sensor and loud alarm and light are great too. Cheap compared to a pan. Off ebay for $60-$75. Adding the auto valve to the system for this season.

I use the steam from the flue pan to heat the sap from high 30's to 185-190 at the float box. When first starting it is easy to boil in the preheater until we start drawing of syrup. Preheater is all stainless now. Melted some pvc in the first version. V2.0 is easy to clean.

PM and I will forward some pics to you.

[Fleman202]

Have people had problems with drop flues be hit with wood when it is being loaded?

The ground is pretty much flat so the only way to get slope is to start higher on the end trees. How much slope is enough to get "good" vac on 3/16 tubing?

[Machinist67]

To get good natural vacuum you need 30 feet of fall from the last tap. I do not think tapping high would be worth the trouble. Depnending on how many taps I would recommend a sap sucker for a small bush, if you have electricity.

[billyinvt]

I went ahead and spent the money on the right pan and figured I'd build the arch to fit rather than the other way around. I have an empty 27' x 60" fuel oil tank that I'm going to cut the top off of. I'm going to barter for some welding help and buy a barrel stove door kit from Vogelzang. I'm definitely working out in my head things like insulation and sap warmers. Can't sleep!

[psparr]

I just posted a few pics of my oil tank arch for someone else in another thread, but here's a few for you. As far as the door, I was looking into the Vogelzang door too. The opening seemed too small to feed the evaporator well and quickly. I ended up just cutting out the door the size I wanted and welding angle around the opening as well as on the door itself. A couple 3" door hinges and I was in business. I also used the top of the tank to extend it to fit a 2x6, and made the stack out of it too.
Good luck and have fun!99969997

[Loch Muller]

If I were you I would try and put at least 50 taps on tubing for this season. I tapped 205 on buckets last year and that was doable, but a lot more work than it needs to be. Look up the threads on here about diaphragm pumps for vacuum, they can be set up for a relatively small cost. I'd also add the blower first then the preheater if you have the money to based on my experience.

[Schiefe4]

Blowers?
Can greatly increase the efficiency of a wood fired arch.
http://www.uvm.edu/~pmrc/Combustion.pdf

Drop Flue vs Raised Flue?
I like my drop flue. Wood shouldn't be a problem. My syrup pan is over the firebox and the drop flues are after the ramp transition. But the firebox for my old style of an arch is 1/3 total length. I have read for gassifaction to occur your firebox should be 2/3 total length and a different style ramp used.

I think the biggest benefit of a raised flue over a drop flue can be read in the link below, second to last paragraph. Liquid in the syrup pan does not
have the ability to run back into the flue pan (raised flue) when the fire starts to die.
http://www.cceoneida.com/assets/Agriculture-Files/Maple/Liquid-Levels.pdf

Good preheating system?

I have one. I really like it, but its something that can be added later very easily under your steam hood.

Buckets/Tubing?

I did 200 buckets for two seasons. Making maple syrup is fun. Washing buckets not so much fun. It's only the last day of the season when you are tired of the long nights in the sugar shack and you have a bunch of buckets to clean. If you already have the buckets I would use them for a few seasons. Make a little money at the hobby so it can pay for some future upgrades.