Almost burned the pan... why ?

[smokeyamber]

Ok, so I was running the 2x5 divided pan at around 1 1/2 inches and the temp got to 7 above so I did a couple draws. Temp went right back up, I opened the draw and nothing came out... so :o .... ran around back and opened the float more... my friend who as helping reported temp was still climbing... :o... I drew some sap from the head tank and started it down the back channel... temp was still climbing... reached 230... and finally the sap pushed the syrup out ... we kept flushing til the temp came down , then I set the pan to 2 inches+ to prevent this from happening... pan did not burn.. but I sure don't know why the float did not keep up... should I open it up more when I am firing it hard to compensate ?

so what did I do wrong ?

I plan to finish what I have on had and drain and clean the pan to make sure it isn't scorched..

[psparr]

Before the first draw, syrup is sometimes made in channels before the draw off because of the heat in the middle of the pan being higher than near the draw off. So your temp might not be at syrup at the draw off, while your already at syrup elsewhere. Keep your eye on the temps throughout the syrup pan. If your gradient is off like this, start drawing off to draw the syrup toward the draw off before things get out of hand. You can put what you drew off back in the syrup pan. Once you start drawing off syrup, things will even out as long as your firing regularly.
When you started your emergency draw, it took a while for the syrup to snake through the channels and give the float the idea the pan needed more sap.

[fisheatingbagel]

How high is your head tank? You want to make sure you have enough flow when your float valve opens up. I had this happen last year. During a draw off when the temp started rising the sap couldn't keep up with what I was drawing off and I noticed the flow from the float box was slow. My head tank was low, and about a foot above the evaporator so it couldn't supply sap fast enough. I raised my head tank this year to 6 feet and never had any problems.

[smokeyamber]

Awesome information , thanks. I did in fact observer the middle channel was looking close just before the incident and since my head tank is not super high up the float was a bit sluggish. I will draw sooner in the future when I see this and I learned to reach over the pan and hold the float open to flood the pan when the head tank was getting low. I will raise the head tank once I upgrade my sap pump to lift higher...

Drained the pan last night to clean and was happy to see that while I made some thick syrup I did not scorch the pan.

Thanks again, this forum has kept me out of trouble and in the maple for years ! ;)

[Pibster]

I've run into the same problem a few times. How much higher should the sap tank be above the float?

[billyinvt]

This very thing happened to me earlier this season. When the temp gets that high in the syrup pan it is usually mostly bubbles. Bubbles have a hard time getting through a ball valve. I used my scoop to manually bring some liquid from the back pans forward until it came down enough to draw off. My float wasn't the problem. I had plenty of sap getting into the back pan, it just wasn't moving through the channels fast enough so I had to do it by hand. I've seen old timers do this for years.

[Maple Man 85]

Good insight, I had have the exact same thing happen to me. Don't have a float box but I regulate my flow from a SS ball valve and I couldn't keep the sap flowing quickly enough in the pan. I had more sap to put in my gravity tank so I just added more and I was ok next season I raised it.

[Russell Lampron]

I think you were making syrup in the middle of the pan. Watch your foam and when it looks like syrup in the middle channels and not in the channel near the draw off you're making syrup in the middle channels and need to get it moved over before it burns. I usually start my first draw off at 5 or 6 degrees and watch the foam and temperature. I pour the near syrup into the middle channels with the draw off valve opened to help push the heavy stuff to the draw off. After the first draw off the gradient is set and draws are normal after that.

[mellondome]

When you pass syrup,the bubbles rise more which artificially raises the level in that area. This prevents the sap from flowing forward and your float will not put more sap in because it is at the set level where it is. If you add sap when this problem arises, it is best to add it to the problem area.

[adk1]

Great thread this happened to me this year too. Seems that my two middle channels boil harder than my draw off channel. I will start drawing off some and dumping it back in to get the middle channels to start moving around next time

[jpcole]

Two things I do, use a couple drops of defoamer before it gets to hot and keep a small bucket of sap available to add to cool it off quickly.

[MapleMike]

One other thing to do. When you reload or fire, with your first piece of wood move all the raging wood to the right in your arch (assuming your draw off is on the right) this keeps the hottest part of your fire on your draw off side. Load all new to the left. Helps keep the gradient flowing in the right direction.

[Ghs57]

Two things I do, use a couple drops of defoamer before it gets to hot and keep a small bucket of sap available to add to cool it off quickly.

My emergency bucket of raw sap saved me when I was distracted by a problem with the head tank. I thought i smelled burning syrup, saw the temp was near 30, and poured some raw in the syrup pan. The temp came down, and there was no evidence of a burn. Figured I only had seconds to spare. Be prepared!