30"x8,10,12,? evaporator question

[Bucket Head]

Hi Guy's,

Not for this season, but I'm still thinking about streching the rig I have now, instead of getting both a wider and longer rig. There are several reasons for wanting to stretch rather than replace, but thats not why I'm writing.

I'm wondering how long could I go. How "long" of a syrup pan and flue pan should I go?

I know a lot of people have stretched their rig's, but what is the "limit"?

How long of a flue pan could my 30" wide fire box and blower heat? Would I get a good boil throughout an 8' footer, but not the 10'? Or good boil in the 10' but the bubbles would trail off at the rear of a 12'?

Theres no sense in having a long pan and only a partial length of it boil vigorously.

Who has a 30" wide rig out there? How long is it? Do you get a good boil throughout your flue pan. Raised or drop flue on your's?

I'm would like to hear from some of you that have experience with a 30 incher.

Thank's,
Steve

[RileySugarbush]

I don't see any reason not to have a long flue pan that doesn't boil violently along it's whole length. In your case with the 12 footer, what if the back 3 feet didn't boil hard? That last few feet is still acting like a super preheater, energy is being extracted from the flue gases so completely that you will be very fuel efficient, and stack temp will be low, meaning you are not wasting energy.

[Flat47]

Looking at some older reference guides, it looks like most brands made 30" arches up to 10'. Leader and Small Brothers both listed them with a 6' flue pan.

[maplwrks]

Steve, I have an 8' rig and I like it. I don't know if I would go longer or not, as I wonder if the firebox could support a 10' or larger rig. I would hate to put all the work and $$$ into lengthening my rig if I couldn't make the last 2' of flue pan boil. I think if you are considering lengthening your rig you should probably think about a wider rig also. The other thing to consider is: How well do like this evaporator?? If you are looking for more production, you might want to look at RO. Just my thoughts......

[maplwrks]

Steve---got a little ahead on my typing.....I think you would greatly benefit from an 8' rig.

[TapME]

There is a person on the trader that had a 24 foot rig, I think it was for sale in the classified ads. now that is using all the energy from the wood.

[DS Maple]

I think you would be OK with going to 8 or 10 feet. Ours is 36" wide, 12' long with an 8' raised flue pan and as long as the wood is plenty dry we get a very rapid boil along the entire length when the blower is running. If you can run the blower fairly high you might even produce enough heat to go up to 12'. Then again, as others have mentioned, it doesn't necessarily have to boil rapidly along the full length in order to work.

[WESTVIRGINIAMAPLER]

I would love to have a 8 or 9 foot flue pan for my 2x8 and convert it to a 2x12. If you put a big enough blower on it, you could make it boil with a 12' flue pan.

[Bucket Head]

Thank's for replying guy's. Now I have a few more questions.

Would I still have the same size syrup pan, regardless of the flue pan length? Would a two footer be big enough for an eight or ten foot flue? One of the rigs mentioned above was ten feet long, with a six foot flue. So the syrup pan had to be four feet long?? Wow. Unless I'm not reading that right.

I guess right now, the overall flue length is not critical, but the syrup pan sizing needs to be correct. Too small of a pan would cause problems, or would too large a pan be a problem?

Brandon,- You would keep the same syrup pan even if you extended yours to a 2x12?

As for the blower, the amount of air you send in is related to the maximum length of pan? I figured too much air would send too many ashes and even coals out the stack. I have the blower on my rig "restricted" a little or ashes and sparks are all over the place.

And Yes, I really like the arch I have. I would rather not get a different one.
Its homemade, but everything on it is three times heavier than it needs to be. Its framed with heavy angle and channel, and the sides are 1/8 steel. This thing won't rust or burn out in two hundred years. Also the grate is an old cast iron street drain. Very thick and very heavy. I would hate to send this down the road and be sorry I opted for a "not so heavy duty factory made one" and then have warpage problems.

I really would like to expand this one, I just need to come up with the optimum pan sizing.

Steve

[dano2840]

if you have a 2 ft pan on a 12 ft rig its not going to work well, your flue pan only concentrates your sap up to 15% then it enters the syrup pan, you will take along time to make syrup and because it took so long your syrup will be darker from cooking for such along time, your pan ratio is supposed to be 2/3 flue pan to 1/3 syrup pan, 3x8 = 2ft syrup 4ft flue, 3x12 = 8ft flue and 4ft syrup as for too large of a syrup pan........ i dont see a problem with it, the older rigs, that were used here in the valley and on my farm were 40"x12s and 4x12s and alot of them had 6ft syrup and 6 ft flue, i have a 6ft syrup pan in the barn for a 40"x12 i think, its 6ft though, so i dont think you can go to big of syrup pan but you may loose efficancy as 75% of the evaporation goes on in th flue pan ( yes i know it goes into the syrup pan at 15% sugar but 75% of the evaporation happens in the flue pan, what we were taught at the boiling school at the maple school, refer to the rule of 86 and thats how the calculation works out)

[tapper]

Bucket Head,

I have a 30x8 drop flue airtight arch. I run 1600 degree stack temps with no effort and feel that if my rig were 10 or 12 feet long I would not be wasting all that heat up the stack. I would rather see stack temps of 800 or 900 and I think a longer flue pan would achieve that. The syrup pan is 3 feet long and I think I would leave it at that.

[WESTVIRGINIAMAPLER]

I agree with Jon totally and if I had a 9' flue pan, I don't think making darker syrup would be much of an issue. I am pushing 65 to 70 gph and sometimes more during the peak boiling hours thru a 2x8, so I wouldn't worry about darker syrup. They make some 2x8 with a 2' syrup pan, so wouldn't be any different with a 3' syrup pan and 9' flue pan. I ask Randy if Leader would be me a set of 2x12 max revolution pans with a 9' flue pan, he never responded. He knows I am serious, guess he didn't know what to say. I am not interested in them now, just wondering if they would if I ever was. I think I could boil off around 150 gph with a 2x12 and 9' max flue pan. I would be using same amount of wood as I use now boiling off 60 to 65 gph, so I would then stretch wood useage from 15 to 1 to about 37 to 1. Running 1650 to 1700 stack temps, I don't think I would have any problem making the entire flue pan boil like crazy.

[Bucket Head]

Thank's guy's.

I guess if I were to go up to an 8 footer, the 2 foot pan would be alright. If I go bigger than that, then the 3 footer would be best.

I would love to get a MAX pan, but unless I win the lottery, its not happening.

At most, all I will be able to do is go with a standard raised flue set-up. And to be honest, cost might make that hard to do.

Like I said, I'm just in the thinking stage right now. I do know that inorder for my father and I to advance our maple operation, we need to process sap better.

Steve

[DS Maple]

Just out of curiosity, has anyone looked into prices on those Max pans? Or even better, how about a Max pan made of copper!