Increasing the Efficiency of My 2x6 Arch By 80%

[PaulRenaud]

<< This is my first time posting photos, so I apologize that they seem to be uploaded upside down. Not quite sure how to fix this, so please bear with me. >>

2060120602

My arch supports a 2-part finishing pan and a dropped flute evaporator. I raised the arch under the evaporator using a 45' slope and created a 1" deep channel under the pans with a cyclone cavity about mid-pan.

2060320604

I also added a flue damper and a chimney pressure & air temperature monitoring mechanism.

I haven't used this new configuration yet to make syrup, but my tests on boiling water show an 80% improvement in wood burning efficiency. Looking forward to seeing what difference this will make this spring!

Paul

[ecolbeck]

Curious to know what the theory is for the cyclonic cavity.

I would skip the damper. It will only serve to slow down your fire which is not the point of an evaporator. The notion that a damper “holds back the heat” has no basis in reality.

[Sugarmaker]

If you have created the magic evaporator I give you lots of credit. Making continuous improvements to our operations is part of the fun of this hobby/ business. 80% is a big jump! Usually a 5 to 10% improvement is very good. Keep boiling! And keep posting pictures too. You will get better at that the more you post. Doy you have some numbers on the gallons per hour boiled before and after improvements? I would tend to agree on the stack damper unless your burning fuel oil then a barimetris damper is appropriate. Usually any draft control on wood will tend to slow the boil rate. Wood fire needs to run about as hot as the rig will stand and not have a meltdown.
Regards,
Chris

[PaulRenaud]

Curious to know what the theory is for the cyclonic cavity.

I would skip the damper. It will only serve to slow down your fire which is not the point of an evaporator. The notion that a damper “holds back the heat” has no basis in reality.

The concept is based on research published in Quebec that the air is compressed by the ramp and expands again when it enters a shallow chamber after the ramp. This causes an air flow around the chamber, like a cyclone, which causes the air to be used twice in that area to heat the evaporator above rather than going straight out the flue.

The purpose of monitoring air pressure is to check that the air is not escaping too rapidly up the chimney and to use the damper to regulate the flow.

[PaulRenaud]

If you have created the magic evaporator I give you lots of credit. Making continuous improvements to our operations is part of the fun of this hobby/ business. 80% is a big jump! Usually a 5 to 10% improvement is very good. Keep boiling! And keep posting pictures too. You will get better at that the more you post. Doy you have some numbers on the gallons per hour boiled before and after improvements? I would tend to agree on the stack damper unless your burning fuel oil then a barimetris damper is appropriate. Usually any draft control on wood will tend to slow the boil rate. Wood fire needs to run about as hot as the rig will stand and not have a meltdown.
Regards,
Chris

This is not magic, just applying research and best practices as published by Quebec producers. The % improvement is also likely a testament to how inefficient I was previously!!

The research disagrees with your comments on heat. The purpose of the heat is to boil the water out of the sap and we all know that water boils at 100' C. Any heat above that temp is unused and just goes up the chimney. The goal of an efficient evaporator is to maintain the boiling temperature while minimizing the quantity of wood used to maintain that boiling point. Gallons per hour is an imperfect metric since it is largely determined by the surface area of the evaporator (assuming you are maintaining enough heat). A better metric for efficiency is quantity of wood per hour of operation.

I haven't used these mods yet in full production, but in tests I was able to bring my entire evaporator to a boil using only 4 1x4x16" cedar shakes (not counting the bit of kindling used to get the first shake to burn). I thought that was pretty good and am looking forward to reducing my carbon footprint as a nice by-product.

[SeanD]

Gallons per hour is an imperfect metric since it is largely determined by the surface area of the evaporator (assuming you are maintaining enough heat). A better metric for efficiency is quantity of wood per hour of operation.

It's not necessarily a better metric, but a different one. You are finding your improvements have given you an 80% improvement/reduction in wood consumption. They are asking if there has been an improvement in boil rate. That's an important metric too. Share your findings when it's up and going.

[ecolbeck]

The concept is based on research published in Quebec that the air is compressed by the ramp and expands again when it enters a shallow chamber after the ramp. This causes an air flow around the chamber, like a cyclone, which causes the air to be used twice in that area to heat the evaporator above rather than going straight out the flue.

The purpose of monitoring air pressure is to check that the air is not escaping too rapidly up the chimney and to use the damper to regulate the flow.

This sounds interesting. Can you cite the research that you are mentioning?

[Sugarmaker]

Paul,
Sounds great to me!
Keep boiling!
Regards,
Chris

[PaulRenaud]

This sounds interesting. Can you cite the research that you are mentioning?

"L'evaporateur au bois", Vincent Poisson, a forestry engineer working with Club Acericole du Granit, Lac Megantic, Quebec, Dec 2014 - it is in French, a 1.5 MB PDF that I cannot upload as an attachment.

There are also several French-language Youtube videos on practical implementation of his research published by Goudrielle at LesSucriers.com which is a french language equivalent to the Maple Trader. IF you Google in French you can find continuing education videos by the Quebec government on best practices which cite Mr. Poisson's research (which is how I found the document). If you understand French, Goudrielle's videos are interesting as it shows him refurbishing several different small-to-mid-scale evaporators around Quebec. He posts before and after videos and cites various before/after measurements that he takes on efficiency.

[ecolbeck]

"L'evaporateur au bois", Vincent Poisson, a forestry engineer working with Club Acericole du Granit, Lac Megantic, Quebec, Dec 2014 - it is in French, a 1.5 MB PDF that I cannot upload as an attachment.

There are also several French-language Youtube videos on practical implementation of his research published by Goudrielle at LesSucriers.com which is a french language equivalent to the Maple Trader. IF you Google in French you can find continuing education videos by the Quebec government on best practices which cite Mr. Poisson's research (which is how I found the document). If you understand French, Goudrielle's videos are interesting as it shows him refurbishing several different small-to-mid-scale evaporators around Quebec. He posts before and after videos and cites various before/after measurements that he takes on efficiency.

Found it. Thank you!

[Maple Lady]

<< This is my first time posting photos, so I apologize that they seem to be uploaded upside down. Not quite sure how to fix this, so please bear with me. >>

2060120602

My arch supports a 2-part finishing pan and a dropped flute evaporator. I raised the arch under the evaporator using a 45' slope and created a 1" deep channel under the pans with a cyclone cavity about mid-pan.

2060320604

I also added a flue damper and a chimney pressure & air temperature monitoring mechanism.

I haven't used this new configuration yet to make syrup, but my tests on boiling water show an 80% improvement in wood burning efficiency. Looking forward to seeing what difference this will make this spring!

Paul

I'm curious to know how this worked out for you this season. I'm looking to change my evaporator to use more of the wasted heat that goes up the stack.

[tcross]

I have an evaporator from Thor (quebec mfg). it's a 30" x 8' raised flue (7" flues). the part of the arch that is under the flue pan is just like you have made. however being an 8' long arch, there are two ramps and drop offs. that rig boils awesome (was getting a consistent 60 gph and got up to 67 pushing it... stock, bare bones rig). however, it also eats wood! i dont' have anything to compare it to, but it was not easy on my wood pile this year. i'm sure if it was air tight, and had aof it'd be a lot more efficient!

[wmick]

Good Job PaulRenaud ... Good to try new things and make improvements......
Looking forward to seeing your results next year.
In the HVAC industry they are making furnaces and boilers that exhaust through plastic pipes.
I think we are a little bit old-school, yet. keeping the chainsaw industry in business...
Lots of room for improvement...