Defoamer Placement

[johnallin]

Okay, for the past 11 years I have been adding defoamer right near the draw-off box on my syrup pan and the near the exit of hot sap in the flue pan. I add 2-3 drops about every 10-15 minutes in both spots and it seems to have been working very well. Once up to speed, we get small draws about every 20-40 minutes.

I have always been under the impression that the foam (and hot syrup) would move towards the defoamer and - to avoid syrup reversing in the pan - to never put any in the middle channels of the pan, and that you could "pull" syrup around the pan by using a drop here and there...

Boiling last night, it was taking an inordinate amount of time to get to 219-220 in the draw off channel. I had a normal amount of foam building up in the two center channels and the rear draw off channel-it's a Revolution set of pans. In frustration; I added 3-4 drops at the draw-off box and another 3-4 drops at the other end of that channel. Bammm! within about a minute I had an enormous draw, it was like a dam had breached.

Later after I cleaned up I started reading old posts and anything else I could find on defoamer use. What I found puzzled me in that what I've been doing is the opposite of what I should have been doing! That's not so surprising.........

Question: Is the correct placement of defoamer at the exit of hot sap in the flue pan, or at the exit of hot sap at the end of the syrup channel?
If it's the latter, it goes against my understanding of how defoamer pulls syrup around the pan.

[Daveg]

If you add defoamer "here and there", and 3 or 4 drops, you're overusing it, in my opinion. I only use it to cure the problem of foam rising in the pans and I only add 1 drop at a time, wherever the foam is. 2X6 drop flue.

[Russell Lampron]

With my air injector I find that I rarely have to use defoamer. I usually only need to use it in the flue pan when the evaporator first starts to boil. I add it at the rear of the pan so that it can spread across both sides of the partition in the middle of the pan to knock the foam down quickly. I don't remember the last time that I used it in the front pan but when I did I put a drop in near the draw off.

[mainebackswoodssyrup]

We hang a defoamer cup in the flue pan and one in the syrup pan, about 3” above the liquid level. This works good and kills the foam before it becomes a problem. We might add a drop or two from time to time but not much since adding the cups in the pan. The boil will spread defoamer around rather quickly, not sure it matters where you add it?

[Maplewalnut]

When up and boiling I only add defoamer to my flue pan. With that said I can quickly establish a gradient at start up by adding a drop of two at my draw off point and the last section of my syrup pan closest to draw off. The denser syrup will migrate to the defoamer and prevent that extra large first draw off of the day

[Road's End]

You can definitely move syrup (or near-up) with defoamer. Leader has a great presentation they put on at their open houses a lot about where and when to use it. I add a drop or 2 in the flue pan every time I fire and that usually controls any foam problems. If I add it in the syrup pan it is a drop by the draw off and a drop by the rear of the pan at the other end of the last channel to the draw off. Works perfectly every time and pulls syrup towards the draw off rather than away or mixing more.

[johnallin]

You can definitely move syrup (or near-up) with defoamer..... If I add it in the syrup pan it is a drop by the draw off and a drop by the rear of the pan at the other end of the last channel to the draw off. Works perfectly every time and pulls syrup towards the draw off rather than away or mixing more.

A few drops by the draw-off is what I've been doing and I vaguely remember the Leader presentation. I was guessing and frustrated when I put it at the opposite end of that channel- - but it sure made things happen.

[Sugarmaker]

John,
I dont think you have been doing anything wrong. Leader does stress the use of this in one drop at a time amounts. Personally I add a drop or two in the hot sap of the rear pan float box, and a drop at the syrup draw off zone. I do that each time I fire (10 minutes).
If I do get syrup building up in the center partitions a drop may be added there also, to reduce the boil and bring the syrup behind it towards that point, which moves more syrup towards the draw off. I think of it as training the syrup or giving it a little help with the gradient.
Question: Was defoamer developed for open pans where there was a lot of foam and or boil up from raw sap? Or was it to replace the pork strips we had hanging in the syrup pan to stop syrup boil over in the 60's?:) That wouldn't go over to good nowadays! Remember skimming the rear pans (Open no hoods)! Things have improved!:)
Regards,
Chris

Regards,
Chris

[johnallin]

John,
I dont think you have been doing anything wrong. Leader does stress the use of this in one drop at a time amounts. Personally I add a drop or two in the hot sap of the rear pan float box, and a drop at the syrup draw off zone. I do that each time I fire (10 minutes).
If I do get syrup building up in the center partitions a drop may be added there also, to reduce the boil and bring the syrup behind it towards that point, which moves more syrup towards the draw off. I think of it as training the syrup or giving it a little help with the gradient. Regards, Chris

Thanks Chris...That's exactly what I was going by - 1 drop at a time at draw off and exit of flue pan. I had Not been adding any to the far end of the syrup channel though. It was cool to see how quickly that pulled syrup over; it was confusing to see all the misinformation on defoamer placement when I looked for answers.

All I need now is a big sign that reads "Close Head Tank Drain Valve - Dummy!" Rinsing cement floors with 6% sap is not fun! Another lesson learned the hard way.

[SeanD]

John, thanks for asking your question and getting a good conversation going. Defoamer is one of those things that people have strong opinions on. I like hearing what people do and trying things out to see if there is a better way.

For the last couple of years, I've added defoamer at the fresh sap end of the flue pan at each firing then sparingly at the draw off channel. It generally works, but there are some factors that affect results.
-If the pan is clean, there's less of a problem. As niter starts to cook on the bottom, foam becomes more of a problem.
-I've found running shallower depth produces less foam - but it can be a scary lightning ride when foam does get going.
-I use canola oil and one drop is not enough. The amount of drops depends on the type of defoamer.
-I typically make syrup in the next-to-last channel every boil, so there's that.

I have one more boil and I might try putting the defoamer at the other end of the sap pan or maybe the beginning of the syrup pan. We'll see how it goes. It's my last boil and I was lazy about not cleaning the pan after the last boil.