Preheater

[hookhill]

I have heard of guys running a copper tube around the inside or outside of the stack to function as a preheater. Id like to build a hood type sometime but was wondering if anyone had knowledge of using the stack and some tube for preheating. Thanks.

[brookledge]

You can definately do something like that but keep in mind a few things
**You don't want to make to long of a continuous feed line or too small in diameter because it will slow the volume of sap that can flow through. And when its calling for sap you want it to get there quickly. That is why most use a parralell style.
**If your evaporator is not calling for sap and the flow is at a stand still, the sap can boil inside the tubing causing vapor lock or other problems. Stack temps vary but usually 600-800 degrees. Sap at a stand still for a short time will boil.
** If you build something make it so that it can be drained easily or that it has no low point that will freeze overnight or between boils
Good luck and hopefully someone else can give you ideas that have built this type.
Keith

[Johnny Cuervo]

I use a copper tubing pre-heater on my homemade rig, once you get the flow rate and length right at works great, It should be removable to avoid scorching when not flowing. Take a look at my pictures; I would be glad to answer any questions. I love to build this stuff!!

[sweetwoodmaple]

Yes, John's system is the best I've seen so far.

Made a "steam boiler" myself by actually running the tubes across the back of one of my past evaporators (inside the stack). It didn't work as stated here because the sap boiled in no time.

I had ideas of putting a hot water coil from a wood burner inside my stack vertically so I could drain and bypass the sap when finishing for the evening. I would then use a circulator to an open tank instead of using this as a sap supply to avoid boiling the in tubes. This open tank would supply my float.

As I thought about this more, it was making my mind numb as you need to calculate the correct flow rate vs. coil length so you don't boil the sap inside the coils and create pressure steam.

Fun to think about anyway...

[powerdub]

John, thats a real nice preheater you made there :!:

[WESTVIRGINIAMAPLER]

John,

You have a tremendous setup and it just keeps getting better year after year. Keep up the tremendous ideas as your ideas will be an inspiration to many :D

[Johnny Cuervo]

Thanks guys, your words are appreciated.
I just signed up for the NY winter conference in Verona, hope to see some of you there.

John

[VA maple guy]

Hi John, I have ben thinking about building a preheater for my home made evaporator, somthing like you have. What temperature does your sap come out at, and how hard is it to keep that temperature with the changes in the fire. Do you gravity feed out of your five gallon hanging bucket, and do you have a valve to regulate the flow rate throught the copper tube or do you just let your pump deliver what it can as fast as it can.
Is your cppper tube 3/8 or 1/2. Thanks, your rig looks great
Gerry

[Maple Hill Sugarhouse]

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[Sugarmaker]

John,
Really nice set up on your evaporator, Preheater, sap pumping system and blower. A lot of work and thought went into your rig.
Chris

[Johnny Cuervo]

Hi Gerry the sap is about 140 F. I keep stack temp between 750- 925 F,
I found out those little magnet thermometers lose magnetism at about 1000F mine kept falling off! It is gravity fed. At the pan I have two self-tapping valves (from an icemaker) after self-tapping I drilled out the hole larger for a better flow rate. These valves can adjust rate for hotter or colder sap. With these conditions the flow rate was about 1 quart a minute. 3/8 copper. Maximum copper to stack contact is very important. If you would like more info or pictures just let me know.

[VA maple guy]

Hi John, thanks for the info and the pictures, every little bit helps. What i'm thinking about doing is feeding the copper pipe on my stack from a fifty five gallon pickle barrel. I plan on using the pump from my UV light to supply the copper pipe on the stack and use a ball valve to regulate the sap flow. I'm not shure if that pump will be strong enough but i hope so.
Gerry

[scw]

Great preheater. I now have 70' of 1/2" wrapped around my pipe in a much more crude fashion. It does have minimal contact with the pipe, but I never thought that I would have problems with it working too well. This is my first year with a commerical evaporator with drop flues and all. I figure that the evaporator will call for plenty of sap before it reaches boiling temp in the copper. We will see. I can always blow it out manually if I have to, as I have a 100 gallon tank 15' high pushing the sap through quickly. We will see what happens.

[NH Maplemaker]

Hi everyone! Have read most all post about preheaters and have pick Brandons brain a little, but hav'nt seen much on steam dampers. What are some of the way you can accomplish this when using 12"stainless steel steam pipe ? Thanks for the help!

Jim L

[WESTVIRGINIAMAPLER]

Jim,

I have a damper in my 10" steam stack. It is a very simple design as it is 1/2 closed or closed. It is a simple piece of stainless about the inside diameter of the pipe with a square bracket which I hang weight in whichever hole to keep it fully open, 1/2 open or closed. You can look at my pics and see if there are any that helps you and I can post some pics in a few days! :D

[Sugarmaker]

Jim L,
I also have a partial damper in my 10 inch steam stack. I feel it is a must with a hood and preheater, to keep the sap as hot as possible and use as much of the steam as possible.
I fab-ed the damper like Brandon and have about 20% open area even with the damper closed. I used a piece of 1/2 in stainless rod for the handle and thru the pipe to support the damper.
Here comes the cold weather that we need to freeze the ground. :D
Last day for muzzle-loader hunting tomorrow. :(

[NH Maplemaker]

Thanks Brandon,I looked at your new pic and they were very helpful!! always enjoy checking to see whats new at your sugar house!!

Chris, thank you also. Have been looking at your site that Adam set up! As I have posted before , wish I was that smart!! Great job.
Chris,hope you don't mind,but I like your idea of a dump and pump so well that i'm building one for my own use!! Got a 1250 gph pump and switch from Sportsman's guide for under $50.00 bucks!! Great idea, I'm adding bucks this year and did'nt know how I was going gather sap by my self most days. Thanks again to you both!!

Do you think a cover like the one on smokestack would work for a steam damper? There is a pic in my album.

Jim L

[Sugarmaker]

Jim,
That lid on the stack would probably work OK. I find that I need to adjust this damper several times depending on how it is boiling. Since you have Oil you may have a more constant boil and may be able to set and forget it? I keep playing with my damper to get just a small amount of steam coming out from under the hood. I wonder if you would get more or less condensate if the damper is near the hood or on top of the stack? ( I bet some one has a suggestion on this???)
Hey a couple of items:
1) Yea we are still playing with the web site. I need to get in and do some updating. I will let Adam know you like it.
2) Your Evaporator and sugar-house looks Great and I really like your kitchen set up! ( I had looked at your pictures before too!) Must be nice having that tubing piped right into the sugar-house! You have a first class operation.
3) This dump and pump idea definitely isn't new. I just like fiddling with things to see if I can make improvements. You got a good deal on the pump and switch. 1250 GPH may work fine for your operation. I sized my pump so that two gathers could come up to the truck with 4 buckets (5 gal.) and dump all 20 gallons and it would be in the tank in 30 seconds. Yea this may be over kill, but I was tired of waiting on this bottle neck and it works great! If you are gathering by your self, your pump will work just fine. If you have a helper just stagger the dump times if needed.
4)Also I do like to share thoughts and ideas related to maple (and bees), so I feel flattered that you have chosen to use some of my ideas.

Regards,
Chris

[NH Maplemaker]

Chris, I take my my steam pipe down every year when cleaning up, so it would be easy to install a damper in the pipe before I put it back up for this season! My wifes cousin owns a liittle sheet metal shop a short ways up the road. I'll talk to him about making one up for me.

I can see by your pics that you love improving on things! Both yours and Brandon pics show you are very particular bout what you do and how you want it to turn out !!!! I especially like your evaporator project. I have my old leader 4'x12'wood fired in the old sugar house. I'm going to rebuild it this summer I hope!! So standby for questions at a later date,yours came out perfect!!

Parts for dunping station will be here this week. Will let you know that goes!! Will only have about 100 buckets at most, as that is all the buckets I have at this time. So your right it will work just fine!!

Jim L

[WESTVIRGINIAMAPLER]

The only problem with a damper on top vs near the bottom is all the condensation would run back down the pipe a lot more than normal. :D

[Daren]

i just finished installing some 1/2 inch copper as a preheater around my 6 inch stovepipe. I have not used it yet, so i am not sure as to how hot the sap will be. I have it hooked up to a quick connect hose adapter to be gravity fed from an outside holding tank. There is a faucet at the bulk tank to adjust the supply to the preheater tubing and a ball valve at the other end to regulate flow into the rear pan. (steam table pans...there are three total). I have about 3 feet of head pressure with constant slope to the whole thing so that it will not pool up inside. When I am out of sap in the storage tank, the whole preheater lifts up away and then rearward to get it away from any heat. I am not sure if I have enough length to the system at this point, so this season will be the big test. I will let you know how it turns out. I do not have any pics since I just got it sweated in last week, but I will attempt to click a few if anyone is interested. Is it time to tap yet? It has been unbelievably warm here as of late. Is this going to affect the sap run once march finally arrives?