Preheater tank idea

[BoarsNest]

Has anyone ever made a stainless preheater tank that rests on the pan and also rests on the transition going into the stack and has a curved back wall that hugs the stack?

I am thinking that having the preheater sit on the transition and hug the stack it would pick up enough heat that I wouldn't worry about losing some of the evaporation from having it sit over the pan.

[wcproctor]

Preheat is pre so let it heat up as much as you want and if it starts to evaporate that is less you have to boil

[kinalfarm]

that sounds like a great idea.

[killingworthmaple]

That sounds great I am going to try that. I was trying to think how I could heat my float box. Thanx

Nathan

[WESTVIRGINIAMAPLER]

You could also use one of the Magic Heat heat reclaimers that mount in your stovepipe and let the hot air that blows thru them blow onto the side of the preheating pan.

[BoarsNest]

Hopefully by the end of the week I can have some pics of what it looks like. The parts are made I just have to weld them together.

[glassman]

be careful not to get it too close the my stacks make enough heat to over heat the metal above the sap line. could scorch the pan side.

wally

[BoarsNest]

Thanks, I didn't think about that. I think I will just have the pan sitting on the transition and leave it away from the stack. The sap will alway be in contact with the bottom of the preheater pan unless I fall asleep.

[PeddlerLakeSapper]

You are going to have scorching on the side of your pre-heater pan as the sap level goes down. We had to put a sheild in between the stack and the pre heater pan last year. It looks like we were about 3"s from the stack.

I guess we could have moved the pre-heater farther from the stack also.

[vtsnowedin]

Just thinking here (smell the smoke). How about a closed tank about three inches thick as wide as the stack taper bottom and two feet high. Inlet from the storage tank would be at the bottom and outlet at the top. The outlet would run to a t with one side going to the pan float inlet and the other rising straight up to an open end that is higher then the top of the storage tank.This would always be fully wet and any pressure build up or steam could rise up un restricted and vent out. Would have to run the top of the vent to a safe location so it can't spit hot sap on people below. You could have this in intimate contact with the stack taper and should be able to get to 212 degrees with the right sized tank.

[JuniperHillSugar]

Now were listening vt.
How about insulating the outside of the preheater?
The vent should be sizeable and exiting to safe area.
I think you're onto something, it has probably already been tried, but it sounds promising.

[BoarsNest]

Right now I have my arch built with about 17" at the stack end. I am building a box that is 24w x 17L x 8h with the 8" flue coming up from the top of the box at the end of the arch. I am planning on setting the preheater tank on the box for about 8" and overhang the evaporator pan by about 2 inches. The bottom of the pan should preheat the sap and then I don't have to worry about the stack burning my pan. I might have to insulate between the evaporator pan and the box as well as the preheater and the stack. I hope to find out by this weekend.

You can check out my progress on flickr.

[KenWP]

I made my preheater pan last year so it was tight against the stack and tried to keep it full but as it went low it did scorch a little bit agaisnt the stack but not enough to do any harm. When I refilled it again it seemed to soften the scorched stuf and slow it down. I just had to scrub it a little harder.

[heus]

I noticed when looking through Bascom's 2010 catalog in the ceramic blanket section it says to insulate the entire back of your pans. Does anyone do that?

[vtsnowedin]

Now were listening vt.
How about insulating the outside of the preheater?
The vent should be sizeable and exiting to safe area.
I think you're onto something, it has probably already been tried, but it sounds promising.
I don't think insulation would be necessary. One side would be hard up against the stack and the other will be bathed in steam while operating. The ends being only three inches thick shouldn't lose much.You'd have to build it to see and to get the size right but I'm pretty sure it would work better then most poor mans pre heaters talked about here. The main advantage being that always being full it wont gunk up or scorch at the end of the boil though you might have to add a pail of water to the sap tank at the end of the season to keep it full. You need to flush the feed line out then anyway. The one thing it won't do that hood preheaters do is provide you with any condensed hot water.

[BoarsNest]

If you want to see what my arch looks like. See my flickr link below. I just have to finish the brick and insulation. Just a few mistakes, thermometer 1/4" coupling too close to the draw off valve. My preheater didn't end up far enough back on the stack box. Other than that I'm pretty happy with it. Let me know what you think.

[Sugarmaker]

Boars nest,
Very nice evaporator. Very detailed and clean. Welds look great!

Makes mine look like I carved it out blindfolded with a dull knife; which I did .....kind of:) Mine looks great from across the yard with your eyes closed:)

Great job. Why buy it when you can build it!
It looks to be a all stainless arch, correct?

Regards,
Chris

BTW nice deer also!

[BoarsNest]

Thanks,

That's correct. It's all stainless and I hope it doesn't warp to bad. We made some charcoal grills and the charcoal pan warped like crazy. I have a guy at work that did all the welding. He's pretty good even with all the mistakes I made on the parts.

[maple flats]

That looks really good. Nice job!

[maple flats]

This won't warp IF you keep the proper sap level in the pans. That is the whole key. SS will not warp at 220 or slightly above and the metal can't get hotter because the sap/syrup is in it.

[BoarsNest]

Thanks for the tip on the sap. I'm just a little nervous for my first boil and can't wait to get started. All this planning and so many things to do yet.

[jrako724]

Guys,
I love all the ideas, has anyone ever tried running a preheater through the stack instead of around it? We tried it last year with a 3/4" stainless pipe and it worked well, this year we want to try a 2" pipe with slow flow to see if the temp rises more or if a smaller pipe works better and run it through multiple times. Ideally we'd like to get the temperature up to 200+. We have access to more stainless pipe so it wont melt like copper could.

[markct]

Guys,
I love all the ideas, has anyone ever tried running a preheater through the stack instead of around it? We tried it last year with a 3/4" stainless pipe and it worked well, this year we want to try a 2" pipe with slow flow to see if the temp rises more or if a smaller pipe works better and run it through multiple times. Ideally we'd like to get the temperature up to 200+. We have access to more stainless pipe so it wont melt like copper could.

copper wont melt either, as long as it has sap in it, and if you run it dry it will scorch from the burn sap inside, weather its copper or stainless. and if it gets too hot then it will boil which could be very dangerous. the reason they use steam to preheat the sap is that it cant go over 212 degrees, so cant boil the sap inside the preheater pipes

[jrako724]

copper wont melt either, as long as it has sap in it, and if you run it dry it will scorch from the burn sap inside, weather its copper or stainless. and if it gets too hot then it will boil which could be very dangerous. the reason they use steam to preheat the sap is that it cant go over 212 degrees, so cant boil the sap inside the preheater pipes

Good to know. We have a pressure release on it so if it boils it will have somewhere to go and shouldn't explode ;). We dont have a large cooker yet and no hood which is why we are doing it this way for now. And Thank you

[WESTVIRGINIAMAPLER]

Last flat pan set up I had was a SS 3'x7' pan and I ran copper tubing all the way thru the firebox and into the pan. Worked great as a preheater and just flushed out the system at the end of the night with a quart of water.

[KenWP]

I am trying to figure out how you run the tube through the arch to the pan. Is the arch not below the pan. Unless the head tank for the tube is high enough to allow the sap to flow back up into the pan. I am trying to figure out some kind of preheater also. My biggest problem is only haveing a 5 gallon head tank.

[3rdgen.maple]

Boars are you refering to the metal on the arch warping or the pans. The pans will not warp unless you scortch them. If you insulate and brick the arch it will not warp either. Just using brick I think the possibility is there.

[BoarsNest]

I found some high temp blanket at a local refractory company that is suppose to be good for up to 2300 deg. It's 1/2" thick and then I am going to put 1/2 brick over the top of it. Except in the firebox area I'm using 2 layers of the blanket and full brick.

[kinalfarm]

if you run the preheater through the stack I dont think it can blow up because the pressure just goes back up the pipe to the head tank and the air caused by heating the sap comes out there. right? there is an oldleader set up for sale on the site and it looked like it had a preheater going through the flu so i pm him and he said it works well.

[WESTVIRGINIAMAPLER]

I had a 3'x7' flat pan with no sections and had the feed tank about 3' feet above the pan and ran the 1/2" copper tubing from the feed tank between the pan and thru a small hole in the arch to pan gasket at the back of the arch and thru the entire arch and brought it out in the front of the arch where the firebox was into the pan. Worked great and came shooting out and bubbling out boiling hot and I had the tubing pointed down into the pan, so there was never a danger of anyone getting burned. I controlled the flow going into the pan with a valve on the feed tank. It would work the same for a sectioned pan, just need to bring it in the correct location in the pan.