Section of cast iron pipe cut in half, using as downdraft nozzle

[ewdudley]

Title says it all.

Original nozzle was eroded. Found an old discarded section of heavy cast iron pipe about 4" diameter. Cut it lengthwise with cut-off wheel and placed the two pieces concave side up to form a slot between them. Two seasons and maybe eight full cord later it has been holding up well and performing A-OK.

 

[salecker]

Maybe add the type of stove and a picture to help others in the same situation.

 

[ewdudley]

The type of stove is a downdraft gasification boiler, I no longer recall the name used to market it, some eastern European brand IIRC, there is a picture of it in my little profile picture, maybe you can tell us what it is.

It has a rectangular nozzle in the bottom of the firebox, same as most any other rectangular slot refractory nozzle we've ever seen, which had eroded.

While excavating near an old stone foundation, amongst some buried brick fragments, broken pottery, and other detritus I turned up a section of cast iron pipe, which presumably had been a drainage/sewer pipe at one time. It was about four inches in diameter. While equipped with all appropriate PPE, I cut it to length and then in half lengthwise with a cut-off wheel installed on a right-angle grinder.

I placed the two halves side-by-side, on-either-side-of and parallel-to the eroded slot, concave sides down, convex sides up, in a tango-uniform configuration, as you might well expect, thus forming a new nozzle, same as the old nozzle. I felt it was a highly effective, economical, and otherwise worthy field-expedient and well worth sharing. If anyone finds this information helpful as-is I would be delighted.

 

[mr.fixit]

The type of stove is a downdraft gasification boiler, I no longer recall the name used to market it, some eastern European brand IIRC, there is a picture of it in my little profile picture, maybe you can tell us what it is.

It has a rectangular nozzle in the bottom of the firebox, same as most any other rectangular slot refractory nozzle we've ever seen, which had eroded.

While excavating near an old stone foundation, amongst some buried brick fragments, broken pottery, and other detritus I turned up a section of cast iron pipe, which presumably had been a drainage/sewer pipe at one time. It was about four inches in diameter. While equipped with all appropriate PPE, I cut it to length and then in half lengthwise with a cut-off wheel installed on a right-angle grinder.

I placed the two halves side-by-side, on-either-side-of and parallel-to the eroded slot, concave sides down, convex sides up, in a tango-uniform configuration, as you might well expect, thus forming a new nozzle, same as the old nozzle. I felt it was a highly effective, economical, and otherwise worthy field-expedient and well worth sharing. If anyone finds this information helpful as-is I would be delighted.

How far down into the original nozzle slot does the curvature of the cast iron extend(if at all) and what do you have to keep the 2 halves separated to keep the nozzle width open ?

 

[ewdudley]

How far down into the original nozzle slot does the curvature of the cast iron extend(if at all) and what do you have to keep the 2 halves separated to keep the nozzle width open ?

The two halves "just sit there" on the floor of the firebox, cut edge down. Since the original slot has eroded, the iron is suspended nearly the full length of the original slot, and after a couple seasons the iron has sagged, but this seems to be harmless at this point. There doesn't seem to be anything that might move them around, although throwing splits in aimlessly could conceivably be a problem. So the width of the slot is adjustable, mine seems to like a gap of about 0.75in/2.0cm, but I do not claim this is the optimal gap, YMMV.

The cast iron pieces are longer than the original slot, and so extend a few inches towards the door. There is typically flow of pyrolyzed gasses doing an end-around through the twin arches and down through the original slot below. I suspect this flow makes the narrower, higher velocity slot more workable.

Prior to the ongoing setup I had tried tossing in a couple of old coal stove shaker grates, again just sitting there. These worked quite well but kinda crumbled after less than a (full) cord.

 

[salecker]

So these are in the primary firebox then?
I was imagining them in the secondary with the flame hitting them.
I use a temporay nozzle opening on my Econoburn last year,5/8 steel with the nozzle slot cut in it.
The one i made out of 5/16 plate didn't last long before it was warping and eroding.The 5/8 was showing signs of erosion when i replaced the nozzle.

 

[ewdudley]

Cleaned ash out of the boiler today and had opportunity to take some photos.

Boiler is an Attack DP. It is a typical downdraft gasification boiler, except perhaps notably is doesn't have tubes in the rear, it simply has approx. 0.30in thick mild steel heatsink fins welded to the back of the water jacket.

Boiler2022-01-31

12 new items added to shared album

photos.app.goo.gl