Anybody got one of these

[billh]

that reminds me of a distant conversation I had with sombody about wrapping a copper coil around the flue for the same purpose. Anybody tried it?

Yes,

The flue pipe had about 20ft of 10mm copper tube wound round and then shrouded with a thin aluminium tube over the coil. The top & bottom of the coil was connected to a horizontal stainless "hot-water" tank ( actually a fizzy drink dispensing tank from a pub) , the top pipe to the top of the tank, bottom to bottom. There was a tap from the top of the tank for supplying a sink.Cold water from the main tank was pump fed to the Tee at the bottom of the coil. The heating of the hot tank was by thermo-syphon action , the tank was about 3 gallon capacity fixed at roof height and the pump forced cold water into the tank/coil circuit when the tap was used.

It was possible to boil the water in the tank from cold in about half an hour . There was a PRV on the tank in case of overpressure due to boiling.

The stove used free fuel( ie scrap wood) . The whole scheme was a complete success story in our application- on a passenger trip boat for washing- up water.

Bill

[WotEver]

How's about............................................. http://www.charnwood.com/charnwood-flue-boiler.asp

Ugly though, innit?

[Nickhlx]

Fins, The flue stays how it is but with a much bigger surface area.

 

 

That is true, but with the cooler flue, the gases would still need some persuasion for them to keep rising as they too would now be cooler / denser...

 

Nick

Edited February 18, 2010 by Nickhlx

[carlt]

I have seen similar, though far more elaborate, arrangements, used to add additional warmth to larger buildings.

 

As they seem to be used mainly in religious structures, their usefulness may be a matter of faith, rather than science...

 

[Nickhlx]

I have seen similar, though far more elaborate, arrangements, used to add additional warmth to larger buildings.

 

As they seem to be used mainly in religious structures, their usefulness may be a matter of faith, rather than science...

 

 

 

:lol: :lol:

 

 

Nick

[Guest wanted]

I have seen similar, though far more elaborate, arrangements, used to add additional warmth to larger buildings.

 

As they seem to be used mainly in religious structures, their usefulness may be a matter of faith, rather than science...

 

 

Have you ever seen one of those in the flesh? I find it hard to believe a man of your calibre would ever frequent such an establishment!

 

Yes,

The flue pipe had about 20ft of 10mm copper tube wound round and then shrouded with a thin aluminium tube over the coil. The top & bottom of the coil was connected to a horizontal stainless "hot-water" tank ( actually a fizzy drink dispensing tank from a pub) , the top pipe to the top of the tank, bottom to bottom. There was a tap from the top of the tank for supplying a sink.Cold water from the main tank was pump fed to the Tee at the bottom of the coil. The heating of the hot tank was by thermo-syphon action , the tank was about 3 gallon capacity fixed at roof height and the pump forced cold water into the tank/coil circuit when the tap was used.

It was possible to boil the water in the tank from cold in about half an hour . There was a PRV on the tank in case of overpressure due to boiling.

The stove used free fuel( ie scrap wood) . The whole scheme was a complete success story in our application- on a passenger trip boat for washing- up water.

Bill

 

any pics?

[DHutch]

I agree, but losing the majority of your heat up the flue is certainly an issue that the stove/flue manufacturers have yet to address. There's got to be a market for a finrad flue or something similar for boats.

Ive never found a problem with out setup.

- If the stoves running flat out you do get amount of heat going up to the flu, with a flue that short its going to be hard not to.

- But if its just chunking out half a kilowatt you can often not tell if its in or not from outside, while it glowing red inside.

 

 

Daniel

[blackrose]

That is true, but with the cooler flue, the gases would still need some persuasion for them to keep rising as they too would now be cooler / denser...

 

Nick

 

Flue gasses rise through a cold flue when you light the stove so I don't see a problem taking some heat away from the flue with fins. Once the fins are hot then the draw will improve.

 

Its single skilled chimneys outside in the cold which are more likely to affect the draw, but chimney lengths on boats are so short that even this effect is limited. (Short chimney/flue lengths adversely affect the draw, but that's a different issue).

[Pretty Funked Up]

I saw these ages ago and thought it was a pretty neat idea.

Pretty sure they arent supposed to be swept, simply replaced.

 

I thought about just cutting some lengths of copper pipe (say 300mm long) then strapping them all the way round the flue with something like a huge jubbly clip, the idea being to drastically increase surface area and aid convection.

 

am I crazy

[blackrose]

I saw these ages ago and thought it was a pretty neat idea.

Pretty sure they arent supposed to be swept, simply replaced.

 

I thought about just cutting some lengths of copper pipe (say 300mm long) then strapping them all the way round the flue with something like a huge jubbly clip, the idea being to drastically increase surface area and aid convection.

 

am I crazy

 

You mean straight lengths of rigid copper pipe strapped around the flue vertically?

 

I don't think it's a bad idea at all. I would have the whole circumference of the flue covered but the pipes would start about 6" above the bottom of the flue (top of the stove) and end about a foot below the top of the flue. Any heat within the pipes would then rise out of the tops.

 

What diameter copper pipes would you go for on a 4.5" flue? From an aesthetic perspective I suppose 15mm would look better.

Edited February 19, 2010 by blackrose

[Bodkin]

Pour a bean can full of paraffin down the chimney every so often, and it'll never need sweeping.

 

Excuse my naivety, being a boating newbie, but is this something you can actually do? It certainly would be less messy!

[blackrose]

Excuse my naivety, being a boating newbie, but is this something you can actually do? It certainly would be less messy!

I think it was intended as a joke. At least I hope so.

 

I was out with a friend once and when we came back to his boat the fire had gone out but it was still hot. To get it going again he chucked half a cup of paraffin on followed by a lighted match. The vapourised paraffin exploded quite violently - so it's not something I'd do on my own boat.

[Bodkin]

I was out with a friend once and when we came back to his boat the fire had gone out but it was still hot. To get it going again he chucked half a cup of paraffin on followed by a lighted match. The vapourised paraffin exploded quite violently - so it's not something I'd do on my own boat.

 

On that note I think I'll stick to sweeping!

[Keeping Up]

Used all the time in Eastern Europe

Here are a couple of rather ornate versions we saw in the Russian palaces of Pushkin and Peterhof:

 

 

 

[Pretty Funked Up]

I like those russian ones.

can you get them in red? hehe

 

re copper pipes - yes I meant solid copper, you could experiment with length and layout abit. May be a layer of lower diameter next to flue (inside ring) and then larger diameter on top (outside ring). I've been trying to persuade my friend who has a log burner to give it ago for a while now but its as yet untested. Might work, might not but in the immortal words of Dr.P... "whats the worst that could happen?"

[Smelly]

Chris you inspired me to do a bit of hunting and I came up with this which seems to be a nifty explanation. Part suction part buoyancy by the look of it.

 

The tapered chimney theory would seem to make sense at it would increase the velocity of the fumes as they rise...

 

I think my bypass idea would probably just cause turbulance and disrupt a clean flow, as do, probably, the kinks in my chimney stack.