drop in boil rate

[steve J]

I have a small 2x3 and have been boiling at about 8 gallons per hour but yesterday my boil rate was under 6 I am thinking it might have been weather related with all the rain and fog in area does that make sense?

[WESTVIRGINIAMAPLER]

With rain and fog, the humidity is around 100% and this will definitely affect the boil rate as the water just doesn't want to evaporate.

[sweetwoodmaple]

Did your pan concentration change?

I.E. If you start with a pan full of fresh sap then continue to boil until you have more concentrate, your evaporation rate goes down slightly as the sugar concentration goes up.

Brian

[mapleman3]

I have a barometer in my sugarhouse and watch it closely. I set a pointer on it to what the reading is when I first start. then I set my drawoff therm. for the correct density. as I boil thru the day if the barometer rises, my boil rate goes down due to needing a higher temp to boil for the rise in pressure. essentially the same goes if the pressure drops, so does the boiling point ergo more boiling rate. I adjust the therm up or down depending on that barometric pressure change.

[Maple Flats]

Jim, sounds like what I was going to do next season. Already earmarked the barometer in one of the dream books, forgot whick one but I can find it when ready to order. Great idea!

[forester1]

I've bought a couple good barometers off ebay for $5 each. There is always a lot of them for sale and it's easy to get one for under $10 plus shipping. They are not the fancy ones with boiling point of water like the maple dealers sell but they are just as accurate and built the same. You just have to calibrate it to the boiling point of water yourself. I like the german made round ones that are about 6 inches in diameter. I'm always looking on ebay for maple equipment and got good deals on stainless pipe and fittings, stainless valves, and other stuff. Just find out the shipping charge and going rate to prevent over-spending.

[Seibold's Sugarhouse]

Hello Again,
It's been a while since I logged on. All this Barm. pressure talk has me thinking. I was quite frustrated this year after buying a new Arch w/blower, Building a new Sugarhouse, and adding a hood w/preheater. My boil rate still didn't seem to break 20 gph. I have a 2x3 drop flue and a leader half pint 24"x33" for my syrup pan, everything sits on a 2x6 arch. My preheater has about 18' of 3/4 copper pipe and the temp. of the sap coming out of the preheater was about 150-160. I ran the blower at full power all the time unless the flue pan was about to boil over, (which it did a few times mainly when I put too much wood in the box) My depth in both pans averaged 1". My flue pan was custom made by D&G and doesn't have any float boxes my pans are connected by 1/2 copper pipe and ball valves. I used mostly hard wood to fire. Seems Like something must be wrong with my setup, from reading everything on this site and elsewhere I should be getting at least 25gph????
Any ideas on what I'm doing wrong??
Jason

[pennslytucky]

i think u may be blowing the fire out the pipe. i got 22gph with my 2x6 without the blower. try putting a pyrometer in the stack, and keep the temps below 1000 or ur just blowing ur fire right up the stack

[mapleman3]

Jason, I'll have to look on the map and see how far you are from me, I would love to hop on the motorcycle and swing down and take a look at your arch and see if I can figure it out for you, Penslytucky may have hit it on the head, we could do a test fire if you have things still set up, your air space under the pans may be too much ... draft may be too much.

hard to say without seeing the setup

[nmerritt]

Curious to know how much the barometric presure affects the boiling. Does it change the temp of which you draw off?
Is it worth having one for a small operation.
12x16 house
2x4 leader pan

[themapleking]

How's the insulation- firbricks in the arch? Are your pans touching the insulation or bricks. That will knock down the gph. If your running the blower on high your most likely blowing heat out the stack. If the stack temp is higher than 1200 degrees it's to hot. Whats the chimmey hight? It could be to high.
I'll jump on the Harely and ride over with Jim :wink:

[Seibold's Sugarhouse]

I never got around to putting a thermometer on the Stack this year, guess i should have made it a priority. I don't think it is too much air space under the pans, The fire bricks are almost all brand new and the whole arch is lined with arch board under the brick, split fire brick on the sides and full bricks on the bottom under the flues. I also used pan gasket on the rails and between the pans. The stack height is 15'. I'm a little shocked to hear that I might have been blowing heat out of the stack, I was told, by the guys at leader, to run it at full speed because more air = more heat????? I think I also read that somewhere on this site, However this theory seems to make sense.
Jim, I'm about 1 1/2 hours from Springfield.
Jason

[brookledge]

Jason,
How much condensate were you getting per hour? Are you sure your pre-heater is dripping all of the condensate into the drip tray? If you are having condensate get back into the flue pan then that is going to cut down on your efficiency. Also how often do you brush your flues? It doesn't take much soot to accumilate and that will cut down on you GPH. Your temp out of the pre-heater is fair but would be better around 200. If you don't have a damper on your steam hood try that. That might get your sap coming in up to 200.
Keith

[brookledge]

nmerritt,
To answer your question. Yes the barometer pressure really does change the boiling point of syrup. for the most part the temp. varies between 217 and 221. Many days the temp. can really change alot if the weather is changing. Some days it never changes.
That is why most people use a hydrometer instead of a thermometer.
Keith

[brookledge]

nmerritt,
To answer your question. Yes the barometer pressure really does change the boiling point of syrup. for the most part the temp. varies between 217 and 221. Many days the temp. can really change alot if the weather is changing. Some days it never changes.
That is why most people use a hydrometer instead of a thermometer.
Keith

[Seibold's Sugarhouse]

Keith,
You and I spoke about the preheater issue somewhere else on this site during the season. At first I had a major issue with condensate, I fixed that problem after the first boil with some rubber washers and a better angle on the drip tray. It's hard to say whether or not I got all the leaks, but I did get a ton more condensate. Also I only boil about six times per season and therefore I do a complete breakdown after the 3rd boil (clean the pans, top and bottom)?????
Jason