raised flue or drop flue, what is the dif and which is better?

[smitty76]

:confused: what is the dif of the pan on raised or drop flues. I was in the sap house 2day and noticed that the exit of half boiled sap from the flue pan to the syrup pan is a good 6-7 inch from the bottom. Does the sap at the bottom of the flues stay down there for the hole season? Im sure that it most rotate. Is the raw sap heavier and go to the bottom and then work its way up as the sugar percentage increases?

[KenWP]

The boiling causes enough agitation to keep it mixed. When the bubbles come from the bottom they bring sap to the top with them so it's well mixed.

[smitty76]

so if i were to biuld a new onethat is ok. Is that standard among pans, manufacturers? mine is a small brothers.

[brookledge]

Do a search and you will find alot of previous post on raised vs.drop
I have boiled on both and I'm on a raised now primarilly because the raised was cheaper than the drop.
You will find it boils down( pun inttended) to personal preference.
Without going into more detail look at past post and you will get a lot of good comments
Keith

[smitty76]

thank you brookledge

[Fred Henderson]

The colder sap entering pushes the hot out. Just like hot water has less oxygen in it so it is lighter.

[red maples]

most folks that I talked with on the subject boil on what they started with and stayed with that type. If they started with raised they usually stay with raised and vice/verse. but like brookledge said there are a bunch of threads on this subject.

[nymapleguy607]

As stated before it really comes down to personal prefrence. I like raised flue because I fell it gives me more control over the liquid level in the flue and syrup pans

[3rdgen.maple]

Im a drop flue guy. One less float box to malfunction and ruin a set off pans. Gravity feed tank does not have to be as high in the air. Less fuss bricking the arch. But like many have said it all BOILS down to what you are used to and the preferences you like.

[smitty76]

I'm not sure of the difference between the 2. 3rdgen, you said that a drop flue has one less float. how does that work? My pans both have a float so I have araised flue?:confused:

[vtsnowedin]

Although the drop flue does have one less float to malfunction I think that is balanced by the ends of the dropped flues being exposed to over zealous or exhausted firemen that push long wood in too far and bang the end of the flues. A good way to start a leak. Also when it comes to take the pan off the arch for whatever reason you need plenty of help and some forethought so you don't rest or drop the pan on the corners of the drop flues. Just my two cents from out here in the wood shed.

[3rdgen.maple]

vtsnowedin you would be correct but if you have a drop you should be well aware of where your flues are. What I did just in case was put in a nice heavy peice of angle iron right in front of my flues when I bricked it. Don't get me wrong though they both have there pluses and minuses I was just stating the pluses I prefer. Smitty a raised flue goes up into the pan a drop goes down into the arch. Since the raised flues are higher than your syrup pan you nerd the second float box to regulate the sap in the syrup pan. On a drop the flues are about a half inch higher so it maintains the level in the syrup pan with only one float.

[smitty76]

thanks 3rdgen. so drop flue only has a float box were the raw sap enter flue pan then.

[vtsnowedin]

vtsnowedin you would be correct but if you have a drop you should be well aware of where your flues are. What I did just in case was put in a nice heavy peice of angle iron right in front of my flues when I bricked it. Don't get me wrong though they both have there pluses and minuses I was just stating the pluses I prefer. Smitty a raised flue goes up into the pan a drop goes down into the arch. Since the raised flues are higher than your syrup pan you nerd the second float box to regulate the sap in the syrup pan. On a drop the flues are about a half inch higher so it maintains the level in the syrup pan with only one float.

For sure but some of your volunteer help is not aware of the danger. Not much of a problem on the 3x10 I started out on with a 3x5 flat pan but something with a 3x3 finish pan leaves those flue ends pretty close to the front and random cut small wood can reach them with a thud. Scrap wood with nails in it makes me shudder also. A 2x4 slides in easy and the ten penny in the end makes a pretty effecent spear point. The angle iron guard is a great idea.

[3rdgen.maple]

yes sir Smitty that would be correct.