building a hood and preheater

[ihuntbear]

I have a d&g evap .I want to build a hood and preheater..did alot of searching.Found some old plans for a preheater from 1978..Was wondering if the plans have changed to improved plan ..still havent found anything on a hood..Do i make it tight to the evap,how high do i make it ,do i hood the syrup pan..Ive seen ones made with everything hooded but left a space over the syrup pan.everything hooded with a door over the pan...what works best?? i only want to build it once

[ihuntbear]

32 views and nobody has any ideas??????

[mountain man maple]

If you build a hood and want to place preheater inside make it tight to flue pan only. I have a hood that overhangs syrup pan it has a 8 inch exhaust on it and with placing ceramic insulation in arch now produces so much steam that it is not all contained into hood.

[500592]

Since you have the one pan I would leave a couple sections open so you can what's going on so it should be like 3 or 4 feet long that way I will still work if you get new pans

[Bucket Head]

Take a look at my photobucket pics. I built my hood and preheater and they work great. It will at least give you an idea, and then you can plan/build from there. You'll have to figure for yourself as to how high you want it or how high you can get away with. Mine is a little on the tall side for a rig my size, but I wanted it that way. Its almost two feet high from the bottom of the drip rail to the top of it. The preheater is in the top of it leaving ample room under the drip tray for veiwing flues and sap, adding defoamer, running a flue brush through without lifting the hood, etc. It should fit tightly to the flue pan, or at least as tight as you can get it. There are many variations on syrup pan hoods and I could'nt say which style is best, but I don't care for the ones that cover the entire pan. I like to see whats going on in there! You can't prevent a problem if you can't see a problem starting. Take a peek at my pictures and feel free to ask any questions about it. -Steve

[maple flats]

I made my hood. It is aluminum and is pop riveted together. For the drain channel I used 1" U channel. The channel corners are cut mitered and I welded them with a aluminum welding rod, like a brazing rod using a map gas torch. The rear pan hood fits tight and works well, the front hood is attched to the rear one and is up about 14" to access the syrup pan.
Both are good designs. I copied the design West Virgina Mapler shows in his pictures.
I currently do not have a pre heater. I built one that heated sap well but had issues with the drain tray and removed it.

[ihuntbear]

I fired it up today with water in the evap..Boiled hard in less than 5 minutes..i think this unit is going to work great for me...Does anybody know what 4.5h on the oil fired nozzle means..does it mean 4.5 gallons per hour????

[500592]

Ya I am pretty sure its per hour so on an a good run of 500 gallons if you have the 500 taps you want it would it would be about 100 gallons if that h means hours which is what I think it means

[maple flats]

I never saw the H but the number, whole and decimal is the GPH of oil.

[The Sweet Spot]

I think the hood is kind of self explainable, pop-rivits are great, and I have seen hoods without gutters and hood with gutters. Do yourself a favor and add gutters. The hoods without are draining gallons of distilled H2O back into the pans only to evaperate it again. I have a 3X11 evaperator and the steam exhaust is 10". Most of the preheaters I've seen have an inlet that leads to what resembles a manifold for radiant heat. You could easily make it out of copper T's and a cap on the end. You will have lines about 6" shorter then your collection pan. Build another manifold for the other side. Hang the whole thing clamps from an aluminum frame, supported on four threaded rods for legs. The threaded rods are to make the sap flow uphill. You can now adjust the incline as you find necessary. Look at lots of pictures and see what looks good to you. I have seen preheaters with a coil of copper hanging over a stainless pan. What ever you come up with (HAVE FUN).
Peace Troy

[ihuntbear]

so your saying 4.5 means gph..wow that means furnace oil is 1.17 per liter and there is 4.5 liters in a gallon.which means 5.27 per gallon, times 4.5 nozzle means 23.69 per hour....wow now i know why most burn wood

[motowbrowne]

Unless I'm mistaken, there are only 3.8 liters/gallon. Not a big difference, but it lowers your hourly cost estimate a little bit. It wouldn't be too hard to change to a wood fired arch at some point, but hey, use it for a while til you're ready to get bigger then change it out for a new fancy wood fired arch with some nice pans. Glad you're happy with it for the time being, though.

[ihuntbear]

i don't know why but the canadian gallon is bigger then usa gallon,,, 4.5 liters in a gallon here @1.17 per liter...I heard on the radio today its going down 4 cents tonight

[ihuntbear]

can i change nozzles to a smaller one,,say 2.5 or 3.5..would it make that big a difference in the amount of sap that will be boiled of..this one starts to boil 2 to 5 minutes into it with about 1 inch of water in the pan..how much would the gph change

[ihuntbear]

anybody have any info on nozzles

[500592]

I wouldn't your boiling rate will drop so in the end I will even out butou will just boil longer and relax you just asked about the nozzles today

[backyard sugaring]

My evaporator is much smaller, but when I tried .65 gallon per hour and changed it to a 1.25 gallons it didn't make sense economically for the increased evaporation rate. I ended up using a 1 gallon per hour and it works perfect for my size evaporator. Trust me oil has it advantages if you have to purchase wood oil could be cheaper. The nice thing about oil is you flick a switch and 5 minutes latter you are boiling, and when you want to shut down for the night you turn the switch off and your done. Good luck. Lee

[ihuntbear]

ya its nice to see that much steam,,just thought it would work almost the same with a bit smaller nozzle..i mean this thing boils hard in just a few minutes..The stack gets red at the bottom..it got so hot it melted the flap draft control between the arch and the stack.i had to make a new one...Just thought maybe the previous owner put a bigger nozzle then it needs

[backyard sugaring]

Your nozzle is too big, my stack temperture runs at only at 200 degrees. Can you look into the evaporator and watch the flame it should be a ball of fire? The flame should not touch anything. I have a 7" stack pipe and did the calculations to close the back of evaporator so it is the same as a 7" opening. Good Luck. Lee

[ihuntbear]

i kind of thought it runs to hot..I have a peep hole going into the arch..there is a big ball of fire but i cant look to long or im going to get burned,,lots of heat..Im going to try smaller nozzle to see how it performs..How hot should the stack get???? im going to call the manufacture in quebec to see what size nozzle size it should be.on the nozzle it says 4.5 h...nobody seems to know what H means..4.5 means gph..thats seems like alot of oil to me

[ihuntbear]

ok just pulled out the nozzle it say hollow 3.5 45' H....so im thinking hollow is name brand,3.50 is gph and 45' is 45 degrees h still don't know....i need to talk to a furnace or boiler man

[backyard sugaring]

H means hollow how the flame burns after it leaves the nozzle. 45 degrees means the angle the flame burns after the nozzle. You have a 3 1/2 gallon nozzle that burns 3 1/2 gallon of #2 oil every hour, the flame is a hollow and it in a 45 degrees. Google oil gun nozzles and it will help understand how they work, also Google oil fired evaporators. Good luck. Lee

[ihuntbear]

i cleaned up the burner and noticed a sticker that says the nozzle is supposed to be 45 degree ss which i think means semi solid so i think I have the wrong nozzle in there