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View Full Version : Teaching an auto draw-off to work for you,or it teaching you?



Bruce L
01-19-2013, 12:58 PM
Last year was my first year with an auto draw-off,it is a Marcland deluxe system,but with the season we had(or didn't have) last year,I only used it perhaps a total of 20-30 hours.I realize that Bob and everyone says it should cycle out syrup 40-50 times an hour,but instead it would quite often run out 1-2 gallons of syrup every 15-20 minutes,sometimes closer to the 2 gallons,making me nervous about A- burning the pan drawing off too much at a time,and B- overflowing the pail the syrup was running off into.
I am boiling raw sap,no hood or preheater,and just on the learning curve with the new Vortex,just wondering what I should maybe be doing different boiling to have smaller more consistent draw-offs
Thanks,Bruce

wiam
01-19-2013, 01:33 PM
Biggest thing to get a consistent draw is a very even fire

Gary R
01-19-2013, 06:09 PM
Use a ball valve in series with the Macland. Throttle it back so the draws are slower and then more consistent.

shane hickey
01-19-2013, 07:17 PM
I agree with gary your draw is getting a bad reading its
pouring more then it should with your valve wide open.
Shut it off a 2\3 of the way to have small dumps at a constant
Rate.

Bruce L
01-20-2013, 08:28 AM
I do have the draw-off throttled back to perhaps between 1/3 and 1/2 open,just maybe as William said I need to concentrate more on firing and less on worrying about the draw-off taking big batches.

ennismaple
01-21-2013, 12:51 PM
Bruce,

Having the valve before the draw-off only open 1/4 of the way helps keep your runoffs small. Managing the foam is another big factor. I'm not sure if you got to the LDMSPA meeting in time last year to see Bruce Gillilan's presentation on Boiling 101. He talked a lot about adding defoamer in your flue pan where the sap enters the evaporator every 5-7 minutes. This prevents the liquid in the flue pan and syrup pan from overtopping the dividers - which causes mixing, resulting in large runoffs (batching). We made these changes to the way we boiled last year and we were able to get runoffs every minute instead of large runoffs every 10-15 minutes. Managing the heat in your firebox is also crucial. if you allow the firebox to cool too much before firing the evaporator again you'll get batching. I wish we'd gotten the temperature probes and display for our evaporator because then you can figure out exactly when the fire has cooled off and needs more wood. Rejean called this "firing by the numbers".

FameFlower
01-21-2013, 01:35 PM
I too had a new Marcland auto-draw off last year in the season that did not happen and did not get to use it much and it did not work as I'd like. Is there any thing you all do to trest/train your draw off in advance of the season. I'd like to do a water run before hand (setting the temp down to water boiling temp or so). Good idea, Bad idea?

Thad Blaisdell
01-21-2013, 02:26 PM
An auto draw off is just like every tool in the box, if you use it like a hammer you will hit your thumb. Use it the right way and it will work for the job intended.

Coming off the evavorator I immediatley have a Stainless "T", to the left a shutoff and then straight into draw off box. To the left, a shut off and then the selenoid valve. turn the valve to the selenoid off, run the evap as if you did not have one. As you are able to manual draw off read the temps on the Marcland and adjust it accordingly. open that valve a smidge. let it try to draw off but watch the temp if it goes up crack it a little more and then use the manual to compensate. A couple of times like that and you will have it zeroed in. Good luck

ToadHill
01-21-2013, 05:05 PM
Fameflower,

I think testing an auto drawoff by boiling water and setting it to the boiling point of water could be a potential disaster. With syrup only a small quantity at a time reaches the boiling point and as soon as that leaves the evaporator the drawoff shuts off. With water everything in the evaporator comes to the same boiling point and when the valve opens it could dump everything out of the evaporator if you aren't right there to close the manual valve. Might not happen that way, but better to be careful. Good luck.

Bruce L
01-22-2013, 11:34 AM
Hello Marty,I place defoamer in the flue pan every fire,Bruce put me onto that right away when he came to do a test boil and teach me on the new rig.Worst day was the last day,could have dumped a whole gallon of defoamer in the pan and the dark syrup wouldn't drop,hence there was lots of mixing.I am anticipating this year to be better,as we got our wood in on time,lots of it and good and dry,last year it didn't go in until after Christmas and first snows

1hardmaple
01-22-2013, 11:53 AM
Last year I used a 2x4 flat pan did ok bought a 2x6 this year with dividers , when will I know when to draw off and how much and is it finished when I do or is it basically the same with flat pan finish in different pan really don't want to burn this pan first time out. Thanks any ideas

ennismaple
01-22-2013, 02:12 PM
Bruce L - How often are you firing with that rig?

We also tried Bruce G's trick to partially block the opening between the last syrup channel and the penultimate channel. I think it help reduce backflow of syrup.

It took us almost 2 seasons to get used to our Force 5 because we were coming from 50+ year old technology, same as you. You've only got 1/2 a season under your belt with the new rig!

We installed a stack thermometer this year and will try to figure out what stack temp dictates a re-fire. That should help keep constant heat under our pans and would benefit you too. Definitely not as simple as oil but cheaper to fuel!

sugarman3
01-22-2013, 02:43 PM
850-900 works great for a stack temp my son does most of the boiling and has a timer set any where between 2-3min,depending on the size of wood,soft or hard and how dry the wood is.You would think you go through a lot of wood,but a steady fire gives you a greater evaporation rate,believe me,it took a season for me to see the results.less wood and more syrup produced faster-my 3 by 10evaporated 155-165 gals sap consistantly using this-hardwood limbs cured 7 months-sap10% after RO
VERN

Bruce L
01-23-2013, 09:45 AM
Hi Marty,I have a timer set for every five minutes(if I always remember to set it),better wood this year may change that setting,plus Bruce made an adjustment which I wasn't aware of to roll the fire farther under the flue pan rather than working the syrup pan as hard as it was.

TroutBrookSH
02-03-2013, 08:25 AM
Anyone have pics of their auto-draw set-up that you can share? I purchased the Marcland economy drawoff and am looking at option for getting it set-up. My original thought was to put it in series with my manual draw off, but then I saw a pic where someone had theirs in parallel with manual draw. Thought maybe having it in parallel would allow for an emergency draw should something go wrong. Thoughts?

Greg