new lp fired evaporator

[softmaple]

has anyone used, bought, saw, or built a or the lpg maple evaporator that is sold by the maple guys? i wanted to go that route and use lpg this year so i purchaced a 3 burner 90,000btu stove from cosco and wanted to convert it but other plans got in the way and i built a wood fired one instead but i use the 3 burner and 3 pots as a preheater but my lp tank freezes up. does the lp evaporator that is sold out there freeze up too? can it be converted to natural gas?

[WF MASON]

I've seen many people use the two and three burner stoves, your problem is your using the liquid propane faster then it can evaporate, most people end up hooking up one or two 100 lb. tanks in tamdem to get the evaporation they need.
In my experience it cost $8. in propane to make a gallon of syrup. The three burner stove you can generally put a 18'' x 48'' pan on it.

[brookledge]

Definately need a bigger tank. as WF Mason said propane can't evaporate fast enough. Another thing that might help is the temp of the propane tank. Propane boils at -44 degrees so when it is real cold out it does not boil ( convert to gas) as good as if the tank was warmer. So try to keep tank warmer but best bet is to get a larger tank or hook smaller ones up parallel.

[syrupmaker]

Warmer is good but remember safety also. NEVER put a propane tank inside an enclosed building :!: I can almost bet you would not like the results of an explosion from LP. 8O

Rick

[brookledge]

True, As far as the little 20 lb tanks they are ok inside sugarhouse just have to use commonsense. Most canning units are designed to have the tank underneath them. But do not put real big tank inside.
Keith

[WESTVIRGINIAMAPLER]

One thing is for sure that the 16 x 40 propane evaporator won't boil of 20gph. It amazes me what some of the evaporator companies say about their products. Don't know where Algier got 20gph :?: 8O

[forester1]

Does the size of the propane feed line make a difference? I bought a used 2x4 small brothers finisher I think is 160,000 btu. It has 3 pipe burners. I haven't used it yet. I plan on running it off 100 lb. tanks. Is 3/8" copper line ok, or what size?

[brookledge]

Alot depends on the distance you need to run the copper tubing. If it is a long distance you will need to be bigger in diameter. Maybe someone else knows the rule of thumb on size of tubing. You could always ask your local gas co.
Keith

[gmcooper]

Forester1,
You may not get enough evaporation with a 100lb tank. The surface area is not all that large if you look at it. We use some 150,000 btu propane heaters and usually we have to have the 300lb pig tanks to have them work right. If you get in a bind you can do what some people here do. They put an electric blanket on propane tank to get better evaporation. Also if you are in a jam and the tank is not full you can "lean the tank on an angle to obtain a larger evaporation surface. Do not let the tank tip over or damage the line or connections in any way. These were tips from the gas company employees that deliver to us. Multiple tanks will do the same thing if plumbed correctly.
Mark

[DougM]

Forester, get with your gas co. and they will help you out on sizing the feed line.

Our rig was plumbed with 1" line, so that's what we ran into the building, but the line out of the tank is no more than 3/8". That goes to a high-pressure regulator. The regulator outlet is 3/4", that runs the 10' from the tank to the building, and into a low-pressure regulator. That is connected to our 1" feed. (We also feed a 3-burner "cooktop" from that for finishing)

Our burner is rated at 165,000 btu max., but we only run it at about 1/2 open. We have a 1000 gallon tank, so no freezing. :) Due to an extremely oversized flue we have been averaging about 8 gal. of LP (at $1.63/gal.) per gal of sap, but we are working on cutting that down.

If you convert a rig from wood to propane get some help on sizing your flue. Ours was set up with a standard stack base and 12" flue pipe, and we have found out it needs a 6" pipe. Quite a difference.

[WESTVIRGINIAMAPLER]

I have a 60,000 high output propane burner for reheating syrup and the 20 lb tank freezes quickly. I just lay the tank on it's side and it works great! :D

Doug,

Can you use a barometric damper in your stack as in an oil fired stack???? 8O

[DougM]

Brandon,
Thanks for the suggestion. That is an option, but I didn't want to buy one to fit our 12" stack to use for just a couple of weeks. Since we are almost at the end of the season we have just put a plate at the base of the stack with an 8" hole. (happened to have it around, never throw anything away :) )

My dad is working on an adapter for next season that will reduce that 8" outlet to 6", so we can replace the 12" pipe with 6". I spoke with a friend yesterday who has many years experience in HVAC, and he is going to help us get it set up so we have the right amount of draft. He said "wow, with that stack you're probably raising the temperature of the whole county a couple degrees every time you boil".

So we may end up with the baro. damper, too, if we need to use it to adjust the draft.

[forester1]

Doug, GM, and Brookledge, thanks for the reply. I don't have electricity so the blanket idea won't work. Also the propane truck could not get down my road to fill a pig so I haul in the 100 pounders myself. The plan now I think is just use the finisher to keep the syrup hot or reheat to 180 degrees. I got a good deal on it so I bought it. If it doesn't work out I'll just sell it. The tube from the tanks to the regulator is only 1/4 inch so I thought 3/8" would be plenty from the regulator to the stove. Only a 20 foot run maximum. I'll check with the propane company too.

[WESTVIRGINIAMAPLER]

Jerry,

I think you will be fine with the setup you have. It won't take nearly all of the 160,000 btus to make it crank anyway. I would think it :D should work fine without any problem.

[digman_41]

I used lp to fire the 2x6.6 flat pan I used to have I fired it with a 500,000 btu burner turned down of course to boil as hard as my little tin pans could take.
I had a cement block arch filled with sand up to about 3 inches of the pan.
I could get about 14 gals per hour! I used 100lb cylinders I think it cost me more for the fuel than the syrup I made was worth. Anyway it was fun and we were able to make some very nice syrup since we could turn the heat of in an instant and draw off in small batches. Have fun Mark