boiling on a drop flue

[BreezyHill]

Please do add the length of stack on. I really want to see if this has any affect at all. The reason I say this is the 2x was developed in the days of natural draft. Since you have a fan on the fire the natural draft is...well blown away. You now have forced draft fire; BUT I am still wondering if it will have a positive affect or if the added friction of the extra length of pipe will just increase the back pressure like in a trucks exhausted after a turbo charger is used. The longer the pipe the more back pressure.

Ben

[Outdoorsman0490]

It is 8" stack, I can put on another 2', should be able to pick some up in the next few days.

[Sugarmaker]

I was able to collect about 75 gallons of sap over the weekend and wanted to do a test boil with my new drop flue hybrid pan and block arch. When I had everything warmed up, there was a ton of steam coming off, when I turned the blower on, I couldn't believe how much steam was coming off the pan. I started the fire around 1:30, and had the 75 gal in the head tank empty by 5:30. One thing I did notice, was that the front of the pan, the syrup pans were roiling boil pretty good the whole time, as was the very front of the flue pan; I had thought that the entire flue pan would be roiling boil. I have attached a few images if the firebox and where the flues are in the arch, as well as the steam from inside and outside the sugar house.

From videos I have seen online, the entire flue pan should be rolling like crazy, which is why the pan sides are so high, right? In order to make mine do that, should I make the ramp more of a ramp and taper it closer to the flues; right now it is appox 1" below the flues the whole way back (fire box 22" long, rest of ramp is about 40"). Also, should there be almost no space between the top of the ramp and the bottom of the flues, 1 " is too much? ThanksAttachment 8658Attachment 8659Attachment 8660Attachment 8661Attachment 8662

Also, initially, I was getting used to the float box and the pan had somewhere between 1 1/2' and 2' of sap in it; is that just too much? would everything have been ok if there was just 1" in it. Would it make this much of a difference because I don't have a preheater as of yet, and was just running cold sap from the tank into the float box?

Hi,
After looking at your pictures and your description I believe your running about as fast as this will boil. Your doing a good job! Get some sap and make some great syrup. I think your level is Ok for now. Boiling shallow is always tricky leave that for another day in the future.
Regards,
Chris

[Outdoorsman0490]

I am pulling the pan off today. I have about 6 gal of sweet in the pan, so I figure I did somewhere between 65 to 70 gal in a little over 3 hrs once the pan was hot.

I am going to tweak the ramp design, put more insulation on the sides of the arch, probably try another 2' of stack, keep the pan level set at an inch tops with the float box, and keep more wood loaded in it all the time. And am going to make a copper manifold preheater with a home made hood over the week..

The amount of steam coming off the pan is crazy, but from watching videos on the comp,of other people boiling, I want my whole flue pan to be rolling, and would have to think the evap rate will increase once the boil is more vigorous in the back half of the flue pan.

[Outdoorsman0490]

So I reworked the fire box, which is the first 20" or so, then 20" of ramp up to the flues, then about 20" of flat tot he back of the pan. I also bumped up the stack height to 14' and put a piece of metal in the arch right in front of the exhaust to partially interrupt the flow going into the stack. Also, I made a copper preheater, parallel flow manifold style, 40' of 3/4 pipe, and a home made hood. I have the sap coming out way too hot to touch. All of this has not made the evaporation rate increase. I cleaned the pan and flues today before firing and from start up to finish it took about 8 hours to do 110 gal. I am kind of at a loss; I should be getting 25-30 gph from the pan, not 15 or so. I have 8" stack, is that too big for my set up, is 6" better?

[Outdoorsman0490]

O, and it boils pretty hard on the whole pan now; there is way too much steam to be able to really see in the pan, but it sounds like it is boiling pretty hard over they whole pan.

[lafite]

looks like you are doing the right things. adjusting your fire box and insulation will help. Any other Smokey Lake users have any input?

[Pibster]

Any chance your steam hood and preheater are leaking back into your pan? That happened to me so I had to make a new drip tray. Nothing worse than boiling sap twice.

[Outdoorsman0490]

No, everything drips out. The drip tray under the preheater is tilted towards the back into drip edge and goes into a bucket at a steady stream. The hood itself, all the condensate drips out as well, I am go into to collect that into a bucket next time to see how much water actually comes out.

[Pibster]

It's been a few years since I used a block arch. Maybe the estimated GPH is based on a regular steel arch.