wardd Hatfield

what if the vent is left open to the outside through a stand pipe of 15 feet or more?

3/16" in my opinion would be ok and if i could i'd use hot rolled steel, it's more stable

coil 1/2" copper tubbing inside the barrel near the top

use  at least a 5gal can as a reservoir put the pump between the reservoir and stove so the stove coil will always be full

mount the reservoir as the highest point in the circuit and leave the reservoir vented so pressure doesn't build

use water and antifreeze

maybe not as efficient but the stove can be kept away from the gh

i'm thinking of a system like this for my house

have you thought of heating water and running the water through a radiator an old car radiator would work

heat the water pump it to the gh in insulated wrapped hose

Foxfire7893 wrote:
Hmm, this is all very interesting and you all make some great points. Thanks so much for sharing. What about running the black pipe up and down the length of the barrel or incorporate it to run the length of the exhaust pipe either on the outside up against it or plumb it on the inside of the exhaust pipe. Also having the hot side of the water on a rise will always give you a natural movement although it might be a bit slow. Interesting to hear your results.

the water should be in a counter direction to that of the flow of heat

in other words the water should enter the coolest region and exit the hottest region

if i understand you want to make a loop of the water going from hot to cool several times, that would be less efficient

tel jetson wrote:
any other ideas?  I don't have a piece of sheet metal large enough.

perhaps a roll of paper or cardboard

most anything that could be made to lie flat on a cylinder might work

tel jetson wrote:
I think that would work, but I would probably go through several of those blades getting it done.  this is .255-inch steel pipe.  I figure it would take me roughly the same amount of time as the angle grinder, and I've already got the grinding discs.

in case I do decide to go that route, though, how would I draw a good line to cut?

take a piece of sheet metal that will fit around it and draw a line

tel jetson wrote:
any tips on how to face the ends of the 16-inch pipe?  the initial cut with a torch wasn't exactly precise, and I've already spent rather more time than I would have liked with an angle grinder.

get a metal cutting blade for a circular saw, any big box store should have them

http://www.lowes.com/SearchCatalogDisplay?storeId=10151&langId=-1&catalogId=10051&N=0&newSearch=true&Ntt=abrasive+saw+blade

Erica Wisner wrote:
ice doesn't explode.  much.

steam does. dramatically.

Keeping copper pipe open, with no pinch points, helps avoid flash-steam problems.

That added surface area might replace 1 or 2 extra coils, but could cost you the entire coil (or personal injury etc) if it collapses the pipe enough to restrict flow.

Your die might let you create a consistent ellipse cross-section without collapsing the pipe.  With great care, it might even hold that shape when the coil is bent into place. 

This seems like a small performance tweak to a system that is still hobbling along like a 3-legged horse.  I'd like to see more experimentation with the safe, effective places to put the pipe within the rocket system before trying to refine the pipe's surface area. 

I think it might be possible to collect heat directly off the exhaust, by plumbing the pipe into the base of the barrel or nearby, in which case a round pipe would work just fine.

But maybe that's because I just spent $300 on copper pipe for Ernie to play with, and I sure don't want to create a kink in the middle by accident.

-Erica Wisner
http://www.ErnieAndErica.info

it's a minor point and the added efficiency may not be much but if it were to be done i would use tubing of greater diameter than the tubing going to and from so the cross section area remained the same

and filling the tubing with sand or ice helps prevent collapse

one way to help prevent steam explosion is to keep the water flowing even if you have to add a holding tank

have the inlet and exit in the holding tank and the heat coil as a separate circuit

the downside may be it takes longer to get hot water but there are a couple inexpensive  fixes for that if you're good  at fabricating

Joel Hollingsworth wrote:
More benefit for less effort/expense might be to smear a touch of thermal grease onto the copper. This might also help prevent any galvanic corrosion of the steel.

that may work if the temp isn't a factor

and the expense