Whats your average evaporation rate?

[Dave Lister]

OK, I am not trying to start a peeing contest or anything like that but I was curious what people get for an evaporation rate?
Basically what do you have for an evaporator, what heats it, do you use a pre-heater and whats the average evaporation rate you get on it? And I guess just for fun, whats the fastest you've ever had it going?

I have a 2x4 wood fired evaporator on a brick arch with a 2x2 raised flu pan in the back and a 2x2 finishing pan in the front. I have a stainless 5 gallon box over the back dripping into the flu pan, but the saps still ice cold.
On average I get about 15-18 gph, but managed to get it up to about 25 gph this last season when I got into some really dry pine.

I guess I just want to know what I can look forward to if I go for a larger evaporator in a few years and realistically how much space will be needed once I get myself into vaccum.

[Dill]

I got my old 2x4 up to 20ish with a blower and good wood.

[mapleack]

3x10 raised flue small brothers with a 7 ft flue pan. When woodfired, under perfect condtions 95 to 100 gph. It's set up for natural gas now, and I guess I'll find out the gph in about a month!

[maple flats]

I have a 3x8 raised flue with a 3x6 flue pan, I like to run at 55-60 gph, can go to about 75 but I need to make a deflector similar to what Leader has on their 2x6WSE to keep the geysers contained in the front of the flue pan. Until then I'll stay at 55-60.

[Grade "A"]

I have a 2x6 Phaneuf raised flue on a home made oil burning arch. I have a home made steam hood and pre-heater. I boil about 45-50gph.

[325abn]

I would say I average low to mid 20s. I have had it really low and really cooking to 28 - 30 but at this level I really gota be on my toes! ):

I am thinking of selling it, anybody interested?

http://i2.photobucket.com/albums/y26/reagantrooper/Evaporator/testboil007.jpg

[Fred Henderson]

90 GPH, no blower

[smitty76]

35 an hour forced draft, preheater 2x6 raised flue small bros.

[DrTimPerkins]

OK, I am not trying to start a peeing contest or anything like that but I was curious what people get for an evaporation rate?

First thing ...are you talking evaporation rate INCLUDING or EXCLUDING the syrup production rate? If you're drawing off 2 gal of syrup per hour, you'd need to factor that into your calculations by subtracting it from your total sap processing rate. Evaporation rate typically EXCLUDES syrup production rate. When people mention evaportion rate they usually mean total system processing rate (how much sap you go through per hour). Using evaporation rate also removes the influence of whether you are boiling with sap or concentrate (and the level of concentrate). An evaporator boiling concentrate is going to produce sap at least 4x as fast as the same exact evaporator boiling sap, so the total system processing rate will be somewhat faster, but the evaporation rate is exactly the same.

Given that, the numbers below are from an experiment we did this summer boiling with water...therefore they are evaporation rates EXCLUDING syrup production rates (if you up the number by about 10% you'd be close to total system processing rate). All were done on the same arch, oil-fired. All were a 3' x 10' Leader Revolution evaporator.

Standard Evaporator
Front pan + back pan (no hoods) = 83.3 gal/hr
FP + BP + Steamaway (with hood) = 142.3 gal/hr
FP + BP + SAW + Hood + Plate Heat Exchanger = 152.5 gal/hr

Max Backpan with Enhanced SAW Evaporator+larger oil nozzles
FP + Max Back Pan (no hoods) = 102.2 gal/hr
FP + MBP + Enhanced SAW (with hood) = 175 gal.0/hr
FP + MBP + ESAW + PHE = 189.0 gal/hr

Therefore:

Regular SAW alone increased evaporation rate by 70.8%
Enhanced SAW alone increased evaporation rate by 71.2%
Max BP alone increased evaporation rate by 22.7%
Enhanced SAW alone increased evaporation rate by 23.0%
PHE increased evaporation rate by an avg of 7.5%

Bottom line is that a SAW or or other preheater (steam pan) can greatly increase your evaporation rate and increase your fuel efficiency to a very large degree. A PHE can also help.

The last thing is what we were really focusing on. A PHE uses the condensate from the SAW to preheat the incoming sap. It basically uses what is waste heat to do this. They are fairly efficient, simple and relatively inexpensive. We will be doing considerably more testing of PHEs in maple evaporators this coming season. Will know a lot more in May 2010.

By making all these changes we almost doubled our system evaporation rate, and therefore also greatly increased our total system processing rate (evaporation rate + syrup production rate). The problem....we needed to then get a larger RO in order to keep up with the new evaporator. Adding another 900 taps to our total this year means we really needed it.

[howden86]

515-550 gph

5 x 14 thunderbolt plus piggyback.

[mapleman3]

3 X 8 raised flue, 14" stack, blower, hood and preheater, about 100gph all day , Wood fired with stack temps hovering in the 1400deg range...

[Mark-NH]

Dr. Tim,

Wow, I was really shocked and impressed with efficiency increase of the SAW. Thanks for providing this data. It is great to have an objective resource and I love that you have become an active member.

[ennismaple]

515-550 gph

5 x 14 thunderbolt plus piggyback.

Nice!!! That thing's a Porsche!!!

I've been told to expect 245 USG/hr with our 3.5x14 Force 5 equipped with pre-heater and hood. I'll know for sure by mid April.

[PerryW]

90-100 gph with a 3x10 (3x7 raised flue pan w/ 7" flues).

Wood fired, no hood, no preheater, no blower but always nice dry wood.

[Jeff E]

3x12, with 3x8 drop flue pan, hoods. Wood fired. Average around 100-110 gph.

The real efficiency is matching this with an RO with a concentrate output to match the evaporation rate. My CDL 600 will average 450+ gallons per hour input, 100-110+ output. So my effective rate is 450 GPH.

My RO is usually done about 2 hours before I am done evaporating, so
I think if I add a preheater and up my evaporator capacity by 10%, I will save myself an hour a day. Maybe next year...

[Amber Gold]

I have 2.5x8 raised flue w/ blower and 14" stack. Last year my best was 65 gph with dry/wet/partially green wood. Expecting to see about 70-75 burning dry wood this year. If I add the air bubbler, I might see 80 gph.

Dr. Perkins. That's a great study. Thanks for posting the results.

[Homestead Maple]

Oil fired 3x8 King evaporator with Steamaway. FP + BP = 80 - 85 gph. With FP + BP + Steamaway, evaporation rate is 135 - 145 gals. of sap depending on how clean the Steamaway is and other factors.

[C.Wilcox]

Steam pans, concrete blocks, dry cedar firewood, and a total disregard for my eyebrows gets me a whopping 3-4 gph....excluding syrup production of course.

By my calculations that means I'd only have to add another 340 or so pans to reach Howden86's 515 gph. :)

[Haynes Forest Products]

3X10 WaterLoo Small oil fired preheater on the best of conditions 120 GPH

[Beans Maple]

3.5 X 10 D&G with 7' raised flue back pans, cross flow fronts, hood, preheater, stack damper, oil fired with "big" nozzles....145 g/hr. Added a CDL steam pan this year so we'll see in about 40 day what the good girl does now.

[Sugarmaker]

3 x 10 King. 5 foot BP, dropped flue, 5 foot FP, reverse flow, wood fired, preheater and hoods we can get about 85 GPH. Still boiling raw sap.
Dr. Tim,
Thanks for posting the SAW stats, I know that is what the books say, nice to see data from a real test. (hope the WRU will get close to that too in 2011?) :)
I had never heard of the heat plate system.

Regards,
Chris C

[oldtimesugar]

2by8 with a 6ft max flue a 2ft front no force air preheater or hood
softwood slabs 75ish gph first year with it 08

[KenWP]

Last year 3 gallons a hour British. With improvements I am hopeing for a good 9 gallons a hour. I know that's hopeing for a lot but hopefully Rileys dropped tubes work the way I hope.

[WESTVIRGINIAMAPLER]

Adding to what Dr Perkins said, I think some people inflate their gph #'s by saying what they can do on the best hour for a day or for the season. GPH #'s should include the time you light the match until the evaporator is completely shutdown. Not a lot of difference for oil fired but a lot of extra time for wood fired evaporator.

I have a 2 x 8 with 5' drop flue pan and with the modified arch, I can get 60 to 65 gph including startup and shutdown.

[jlemieux]

2.5 by 6.5 with flat pans and no frills. Dry softwood and 25 gallons an hour at her best.

[Saw Filer]

2x3 flat pan, homemade preheater, nicely dry hardwood split fine,a 12 year old fireman we call Sparky, and we can average 7gal per hour on a good day, (includung syrup production of course). Can't wait to see what the 2x6 will do.

george

[brookledge]

3X12 130-140gph
Keith

[sapmaple]

4x12 wood fired, blower and air tight front, 7 foot drop flue King with steamaway 300 GPH when she 's up to full song which is about 15 mins after match lite

[Rhino]

5'X18' drop flue, piggy back, steam hoods, under grate blowers, 250-300gph. Added over the fire air, and a sap preheater before it goes into the piggyback for this spring, hope to hit around 350 gph. Don't know how the preheating of the sap before it enters the piggy back will add to the gph rate, but it looks like the first few channels of the piggyback never steams that well. should be a fun test come March.

[3rdgen.maple]

Adding to what Dr Perkins said, I think some people inflate their gph #'s by saying what they can do on the best hour for a day or for the season. GPH #'s should include the time you light the match until the evaporator is completely shutdown. Not a lot of difference for oil fired but a lot of extra time for wood fired evaporator.

I have a 2 x 8 with 5' drop flue pan and with the modified arch, I can get 60 to 65 gph including startup and shutdown.

This was discussed in the past with Dr. Tims input and if I recall correctly evaporation rate is based on when the evaporator is stable and at it's max potential and not from startup to shutdown. I think it was after the first hour of operation. Went back and found the post. It is on the Post ADVICE on 10/06/2009 Evaporation rate is based on after the first drawoff when the evaporator is stable.

2x6 with 4 foot drop flue bare bones 40 gph.

[WESTVIRGINIAMAPLER]

This was discussed in the past with Dr. Tims input and if I recall correctly evaporation rate is based on when the evaporator is stable and at it's max potential and not from startup to shutdown. I think it was after the first hour of operation. Went back and found the post. It is on the Post ADVICE on 10/06/2009 Evaporation rate is based on after the first drawoff when the evaporator is stable.

2x6 with 4 foot drop flue bare bones 40 gph.

I know that is what most guys figure, but these numbers are false. Might as well throw out an hour each day and pretend you didn't boil on a wood fired evaporator, just like the time didn't exist by the time you get it warmed up to full potential and then shut it down, you have an hour that you are not evaporating off very much. Oil fired, probably about 10 minutes. I have a meter and I take the total gallon boiled down for entire day divided by total time spent boiling from time I light match until I am done with evaporator and that is true gph.

There have been hours I have probably boiled off aprox 75 gph with my evpaorator, but I am not going to say it boils off 75 gph because it won't do that for an entire day.

[3rdgen.maple]

If that is the case then can you explain to me how the manufactures come up with there gph on the rigs they sell. If they take into consideration all the variable in how people start there fire and how well they stop and how often they fire it and what type of wood they are burning if the arch is oil fired, what type of burner is on it, size of the nozzle etc etc etc.... there numbers would look so rediculous. Hence the reason the number of gph a rig gets is based on when the arch is stable and you are drawing off syrup and yes do not forget to subtract the amount of syrup from the number. When my dad runs the evaporator he sits there with his pocket knife cutting little sticks of kindling to light the fire and when it is finally boiling he likes to use the biggest chunks of wood he can so he does not have to move from the chair and keep loading wood. He likes the nice lazy boils and is getting up there in age and well heck that is fine but if I took his numbers it would be at best probably 10 gph. Then when I take over things change and I like the sap jumping out of the pans and firing every few minutes so do I average his boil rate into mine and get a number that is not fair to the manufacturer of my evaporator?

[red maples]

I think a safe thing to say would be"my whateversize evaporator will boil 75 gph/40 gph what ever, when its at it most efficient point"

this is when:
1. the fire is blazzin'
2. the arch and bricks are warmed up
3. your pans are sweetened
4. your drawing off syrup.

then you can say I am boiling off 40 gph/75 gph what ever.
which I would go by the warmed up number!!!! or maximum gph.
otherwise you can factor in everything else and make it confusing.

[WESTVIRGINIAMAPLER]

No, I am not making it confusing, just as simple enough for a first grader. You start the fire at 8 am and boil till 5 pm and the evpaorator is completely shut off at 5pm and boil off 900 gallon, you boiled off 100 gph. At the end of the day it really doesn't matter if you boiled off 130 gph in one of those nine hours other than if it boosts your ego.

Evaporator companies can get away with posting higher rates than most get because of what is called "puffery" and so do most other sales people exaggerate things.

[red maples]

I agree average over time is easy to do. thats why I say you can say it would be 130 gallons
(using your exapmle) at optimum boiling or how ever you want to phase it. But when other things are taken into consideration like the operator (or whoever is loading wood) and how much your drawing off and what ever else you want to calculate thats when it can start to become that famous math question ...

so 2 trains leave at the same time one from ......:)

[gator330]

I'm all for "puffery" and whiskey. Tonight the lable is green and the gph is 80 (proff that is)!!!!

[red maples]

Proff huh already had a few, I am gessin':lol:

[gator330]

Not if you fire 101 times more per boil. Hey this tennessee syrup is good for my math.

[whiteout]

2X6 WSE, blower, preheater , flue pan steam hood, 35GPH

[Hop Kiln Road]

29 city / 37 highway

[Parker]

When Mighty Marvin (5x16 raised flue-sidewinder preheater, kinda air tight front with blower) is all warmed up and rolling,,,on a perfect night,,,burning NITROMETH (standing dead bone dry oak split fine) we can click off 300 gph,,,,meaning that is what is going into the rig and comming out in a diffrent form thru the draw off or the hoods,,,,,working on a bubbler and overfire air mabey that will add some......???

[Brian Ryther]

6x16 small bros raised flue, flue hood, preheater, blowers, not even close to air tight doors, 24" stack @ 950 degrees, wood every 7min, I can consume 300-350 gph of sap. Average is more like 280gph. Eight hours of feeding the evap like this will just about kill a man.

[maplekid]

4x5 flat pan on a oil drum... wood fired. canm reach about 23 gallons per hour with dry wood. thats with blower and preheater

[tessiersfarm]

Homemade 27" x 6' with 4' flued pan and 2' flat, parralell flow pre-heater and steam hood.

20 gallons per hour real easy and with very little attention.

I usually run more like upper 20's

I can get 35 if I am on my toes, good wood and a fair wind.