Going way over draw temp

[nymapleguy607]

How big is your syrup pan on your 2x8? I have this happen from time to time on my 2x6 with a 2x2 syrup pan. I always blamed it on not being able to get a strong gradient in the smaller pan, and it will start to batch at the center sections of the pan.

[Haynes Forest Products]

NYMaple You said "I always blamed it on not being able to get a strong gradient" I know ill get some flack for asking this but when you say Gradient are you talking about the sugar concentration or the liquid level.

You got me thinking about how I looked at my rig when it was giving me fits because of the highest heat was under my first channel of the first finish pan. I guess my point being was it the density of my syrup causing the syrup to not flow or was it causing the lowest liquid level to be in that area causing syrup to reverse flow away from my draw off. I have corrected it BUT I'm now not sure what I corrected. What Gradient did I compensate for? I believe it was the liquid level differential that I was able to correct with reversing the flow.

[Super Sapper]

Though gradient can be used for sugar concentration or liquid level, it is mostly used for sugar concentration here. My understanding of the gradient in an evaporator is that water if vaporized off and all channels start to lower. Since you are only adding at one end you are diluting what is in that channel as you add sap. As that level in the first channel rises it pushes some of it's liquid at the far end into the next channel to equalize the level. The liquid at the far end of the first channel has a higher concentration of sugar than the incoming sap so the second channel gets to start at a higher level than the first one. As you progress through the channels you get a higher and higher concentration. Even though the level change causes the sap to enter the first channel the sugar concentration difference is what is referred to as gradient.

Now if you want to discuss this over a 30 pack let me know when you are back in Wisconsin and I will see if Joe wants to join in.

[Haynes Forest Products]

I agree with what you said and yet opening the draw off starts another gradient in motion. If all you did was add sap into a channeled batch pan because you dont have a draw off valve then you have a nightmare of the gradient of the first kind.

Now I will be back up in Door County this 4th of July and will gladly meet you guys in Algoma for a few. Plus my sugar shack is always open for some in depth discussions. Heck you never know what I might be willing to part with in the dent and thrown from the truck out of anger pile.

[Russell Lampron]

I draw off heavy on purpose. I have a finisher that I draw off into and when I'm done boiling I correct the density and filter it. It's easier to thin it down than it is to bring it up to density.

I always blamed my small 2x2 syrup pan for not being able to maintain a constant draw and making syrup in batches. I see that you guys are having that problem with larger evaporators too. I increased the depth in my syrup pan from 1" to 1.5" and the batches are bigger with smaller spikes in temperature. I sometimes boil at or near 2" and it's even more consistent. There are times when I can get a draw started and keep it going for more than a half hour.

[SeanD]

This is a common problem for me as well - though I only boil 8%. I have a 2x2 syrup pan with the first channel running the width of the pan then the next four run the length of the pan. The draw off port is away from the arch door back towards the middle of the evaporator.

I end up making syrup in the middle two channels and just try to push/pull it over and out. I used to get worried about it, but now I just live with it. It's part experience, part art, part prayers, trusting the rig and not panicking as the temp rises 2, 3, 4+ degrees over before it peaks and begins a slow drop down again as the heaviest stuff comes around the corner. Of course, I do panic and scoop some sweet from the back to the front. I've learned that when I fire, the cool air coming in drops the boil for a few seconds and the sweet from the back catches up and gives the front pan a push.

I try to fire as far over to the draw side as I can, but it's a two foot pan and there's not too much side to go to. Haynes, you got me thinking about this a little differently. I know the two middle channels are the hottest ones where the syrup is getting made, but I hadn't thought of the draw off channel as being cooler. It's sounds like the same thing but it's not. Thinking more about the draw off channel I realize almost an inch of it's length is sitting on the rail and almost an inch is sitting on the front rail. My draw off channel has maybe 15%? less fire to sit on. I've been focusing my attention on the firing, but it's really a lack of fire or cooling that is my problem.

I have the ability to reverse the flow and draw from the channel that runs the width of the pan, but I can't get it to work. That's a problem I'll post another time.

[Haynes Forest Products]

SeanD I have come to to learn to trust what my fancy smancy guages and probes say. Now it took abouit 5 years of near disasters to get my rig running like a well oiled machine. I reversed my flow and that got the syrup running in the right direction. Then because my new set of finish pans had the temp probe ports in the trailing channels only a was heading over the the rig with a cordless drill with 1/4 bit in hand when I came up with a better solution. I had a friend make up a nice SS clip on temperature probe holder. When you think about it your controlling a valve that is about 12" from the control unit. My probe is 4-6" inside the channel then the draw off box is another 3" on top of the 4-6" piping outside the rig to the valve. Now I understand that YOUR rig might run fine with that but mine runs better when I came up with my probe 100% vertical even slanted slightly into the drawoff box. I get a better reading there.

Now when I boil alone and Im doing all the concentrating, boiling, filtering, transferring, filtering, checking on all the levels, foam pumps things can get hectic. I have float switches and buzzers on everything. My shack sounds like a jumbo jet flying upside down. BUT I get a rhythm going that matches my evaperator and we become one with each other. I control it and it controls me. Once we both settle down and level off at cruising speed we can relax. Now just screw one thing up and the beatutiful music is over and done for about 10 minutes.

Being slow and steady with the changes keeps the rig running at top speed. The things that can throw you off and make the gauges spitter spatter are forgetting to defoam, keep the sap levels on point, forget to fire, bang into a valve and open or close it by accident and the list goes on. Then you decide to change the wrong thing...............what I mean is you decide that scooping sap forward to "HELP" something heck I don't know what but your also depriving some other area of the pan of its sap. next time your walking in a nice orderly line lets say at IKEA and try this just shove the old lady in front of you the one with the Turkey leg half way down her face. Now speed up filling the void in front of you.....get the picture now the guy with the entire kitchen in his cart will run up on you, but your now laying on top of granny doing the Heimlich and now our neat little line is a mess. Once the syrup is traveling thru the channels being pushed along buy the incoming sap that is CONSTANTLY coming in and you draw off is matching it at a slow trickle WALK AWAY.

Now I have a few scoops the screened one and the solid one and I took the 4' handles off and have them in the rafters. I know guys use them for sheeting their syrup to see if its close and that's fine I just don't have much use for them. Now I do remember the time we used them to get a beer cap out of the pan after my idiot buddy dropped it when he reached into the funny looking FOG. Well I was wetting myself with laughter seeing him outside the shack with his arm in a snow bank. What a dumb *** but that's some funny entertainment. Now guys watch the rig I need to go change.

I have learned to just slow it down and quit changing the things that don't need changing.

[mellondome]

For what it is worth, i am running a 2x6 with a 2x2 front pan. Drawoff box is at e back ( grimm /leader ). I run about 1" deep. ( as stated earlier 18%) Once i have the continuous draw going... everything just flows..
You have to be willing to start drawing from the box just before the center gets to syrup. It will go way over syrup for a quart or so then settle down into a nice cotrolled flow. No batching..

[Windy Acres]

Yes, my front pan is 2x2, although it isn't a cross flow, I have a bypass valve that I keep a steady stream about the size of a pencil lead going at all times, maybe I just need to open that a little more-

[nymapleguy607]

NYMaple You said "I always blamed it on not being able to get a strong gradient" I know ill get some flack for asking this but when you say Gradient are you talking about the sugar concentration or the liquid level.

You got me thinking about how I looked at my rig when it was giving me fits because of the highest heat was under my first channel of the first finish pan. I guess my point being was it the density of my syrup causing the syrup to not flow or was it causing the lowest liquid level to be in that area causing syrup to reverse flow away from my draw off. I have corrected it BUT I'm now not sure what I corrected. What Gradient did I compensate for? I believe it was the liquid level differential that I was able to correct with reversing the flow.

When I talk gradient I am referring to the sugar concentration through out the syrup pan. When I have talked with older sugarmakers in my area they have said that a small rig like my 2x6 is harder to make syrup on than a large evaporator. They always said its because you don't get the syrup "pushing" through the evaporator when the gradient develops. I thought that when I added my RO that I would no longer have the syrup drawing in batches, or starting to make syrup in the center partisans of the pan. This never went away, I just make more syrup per hour this way. H20 innovation put out a video of Glen Goodrich's new high brix evaporator and he explains that density gradient doesn't really form in the flue pan, its more to do with the size and linear travel the syrup needs to make in the syrup pan. If you think about a 2x2 syrup pan, most likely there are 4 sections to the pan for a total of 8ft of travel. I believe that truly isn't enough space to work smoothly. From talking and reading what other producers have experienced I think a larger syrup pan with more linear travel will make the evaporator run smoother. I am now debating on having a 2x4 syrup pan made and stretching my arch to 8ft in length, this would give me a linear travel length of 16ft which should help with the flow issues.