boiling water compared to sap

[Grade "A"]

How does boiling water compare to sap. I fired up my new 2x6 last night with a 4 gph nossel on it. I was boiling 48 gph of water, I figure it would only do about 35-40 gph. Does 48 gallons of water = 48 gallons of sap when boiling?
I am thinking that when there is syrup in the front pan there will not be as much evaporation going on, witch would be good because there is so much steam with water I can not see anything until I put a flashlight about 1 inch away from the bottom of the pan.

[brookledge]

I have never boiled water long enough to measure how much water I could boil per hour compared to sap. But anyways I would say you should get the same amount. You will also be removing 1 gal per hour of syrup from the pan.
The only other factor is the temp of the sap coming in. I would assume the water you were adding was 35-45 degrees.
Also is the 4 gal noz. the recommended size. and what is your stack temp.
If you are pushing it hard and have a high stack temp you are losing efficiency.
I guess I could say it is like a car. Put the pedal to the floor and you go fast but use more fuel. Go a little easier and still get there and use less fuel.
To gain efficiency you want to transfer as much heat as possible before it turns up the stack.
Keith

[ennismaple]

Your rate sounds about right. I've been told to expect 4 gph per square foot of pan for an oil fired evaporator.

[peacemaker]

wouldnt u think water would boil off as fast as if u had all fresh sap in your rig as the gradient was set your rate would drop some as the higher the sugar content the higher the temp it boils at in my thoughts thats more heat needed to get that sap or almost syrup to boil hense less gals per hour i wouldnt say alot though

[Grade "A"]

Well I really did not boil for a hour, I boiled 12 gal. in 15 min so I just did the math. I do have a preheater, not sure what the water temp. was but you can't keep your hand on the incoming pipe. I made the arch myself so I don't know what the recommended nossle size is, I have seen 2-5 gph on different rigs but the stack temp was 450 deg. I think thats ok temp?

[brookledge]

If your stack temp is 450 then your nozzle isn't to big.
Keith

[WESTVIRGINIAMAPLER]

Once you get the correct gradient in the pan and a much higher sugar content than water, it should boil off faster. I wouldn't base your expectations on what you did in 15 minutes. There are too many variables involved such as humidity, barometric pressure and other factors. I would guess with your current setup you will average around 40 gph and you may get as high as 48 gph, but better to plan for the lower end and anything above is a bonus.

[peacemaker]

ok so explain that for me brandon ... i may be thinking different so i like to here what your thinking is

[WESTVIRGINIAMAPLER]

What do I need to explain, not sure what you are looking for???

[peacemaker]

well u said closer to syrup boils of faster then water dont understand how that could be

[WESTVIRGINIAMAPLER]

Because syrup has a much higher sugar content than water or raw saw which has no sugar, the higher sugar content will boil harder and faster than just plain water.

[peacemaker]

but it boils at a higher temp and when u boil to me it seems the when its more sap then syrup it boils of faster then the closer it gets to syrup .

[WESTVIRGINIAMAPLER]

I may be wrong and it wouldn't be the first time. Also, I didn't think that syrup boiled at any higher temperature, it is just 7.1 degrees above boiling point of water before it is syrup which is the heat factor. It should boil at the same temp as water??

[peacemaker]

u lost me there 219.1 is higher temp then 212

[WMF]

The correct answer is: Water will have the highest evaporation rate but sap/syrup will look like it is boiling faster because it builds foam over the surface of the pan and actually insulates the surface of the sap which looks cool but retards evaporation.

[peacemaker]

thanks thats what i waslooking for