anyone built a porcupine boiler?

[bkueber]

has anyone built a porcupine boiler? I am looking for a boiler for my steeple compound and came across some info on this boiler type. a central water drum with pipe spokes, capped on one end and threaded into the drum. sounds easy to make, and more stable steaming like a firetube boiler without the welding. I need about 40sq feet for my engine.

[gondolier88]

I havn't built one- but I have recently stripped one down to it's bare bones and if you like I could take photos and post them on here?

Greg

[bkueber]

Greg,

That would be great! and any info you would have on its steaming capabilities and characteristics.

[gondolier88]

Hi,

I'm afraid I can't comment on it's steaming capabilities as yet- it needs a new casing and funnel making.

As soon as it's stemed I will post it on here anyway.

Sorry not to be of help. I'll post some pics on Monday.

Greg

[gondolier88]

Hi,

A few pics as promised;

Greg

[gondolier88]

Couple more;

[Richard Orr]

I havn't built one- but I have recently stripped one down to it's bare bones and if you like I could take photos and post them on here?

Greg

I have often thought about porkeys..seems so simple to build. I would really like to see the insides of an old porky to see if they have deposits built up. Seems that would reveal something about their circulation.

[Brenton Baker]

What are the curved pipes running from the top to the bottom of the main drum, between the quills?
I have seen similar pipes on a few porcupine boilers on the internet, but Googling has not yielded any answers, and they are neither shown nor mentioned in SB&MSL. Are they for circulation ("downcomers")?

[87gn@tahoe]

Brenton,

I think they're just there to get in as much heating surface possible. In the central vertical drum boiler designs, the drum is effectively one big downcomer.

There is a central vertical drum design that consists of nothing but those tubes, I've forgotten the name of the design at the moment.

[DCSmith]

I believe you're thinking of the lifu boiler.

The porcupine boiler has large gaps at the outside of the quills, allowing the gasses to pass without transferring heat, these fill those gaps.