Metal Nozzle Shield Report

[Tennman]

Lots of lessons learned as usual for me this season. The heating season started before we could get storage working, but this will be our last season idling. First I will never let my nozzle opening wear into a funnel shape again. Started burning before T-Day and ran continuously up to about first week of March. Our temps in the South this winter were as relatively extreme for us as those of you up North. So started with a crisp corner nozzle, and a 3/16" mild steel, plasma cut guard slightly undersized of the nozzle opening. I expected some metal erosion and wanted to guard to erode to the ceramic over the season and planned on throwing the guard away. We kept our house warmer, burned about the same or maybe less total wood this season versus last although a much more severe, btu consuming season. But the biggest sign of performance was ash disposal. For the '12-'13 season I emptied my wheelbarrow of ash about 4-5 times. For the '13-14 season one wheelbarrow load of ash. It wasn't just the loss of coals, but by keeping that coal bed longer obviously we got more energy from the wood. The 3/16" mild steel edge held up surprisingly well, but the plate warped from the heat. Next season I'll probably use some scrap 1/4" or 3/8" depending on what's left over laying around the shop. So nice sharp, original size nozzle opening makes a big difference. The type of metal for the shield seems less important than the thickness to minimize warping since I used plain old medium steel. Steel and the plasma cutter is just more available for me than cutting fire brick. Probably firebrick protector would be better, but I don't have a cutter for that. But if there was a blade for my circular saw... maybe.

Really tough winter for all of us, but it all came together for me with well seasoned wood, proper air vent/fan tuning, and a healthy nozzle. Big difference from those painful early years. Next year... To storage and beyond!

 

[woodsmaster]

Thinking I will probably replace my nozzle this fall before we get back into the serious heating season.I will also be installing some kind of protection plate over the new one. I have around 30 cord on the original. hopefully the shield will double that. The new one is made from better refractory according to Zenon.

 

[Tennman]

Huh... wonder if the one I installed is of the better refractory. I definitely will never allow my nozzle opening to get as far eroded as I did. Astonishing difference in performance this season vs last. Last season was my first with 2-year seasoned wood, the best to that point. This season 2-year seasoned wood and crisp nozzle was a huge difference.

I hadn't noticed but Coal started a nozzle protector thread on his Vedo. Based on my one season experiment if you go steel, thickness appears more important than alloy. My plate was plain jane 1018 hot rolled, about the most readily available, cheapest steel plate. Very little erosion but the 3/16" warped 3/8" to 1/2" in one place. January I removed it and beat it back with a sledge but couldn't get it truly flat again. If I had the tools to size fire brick I think that would be a great expendable shield to replace every season.

JT, if you haven't removed your upper chamber side plates start early in case you break one getting them out. I just took a chisel to the nozzle block, but had to reuse the side plates and they get glued in by gunk. Last time I asked Zenon he didn't have any side plate ceramics for the 60.

I will always be using a shield now because it took me and a helper 3-4 hrs to replace my nozzle. I'd be faster this time and I definitely have spare side plates so I wouldn't have to be so careful. But the shield is a huge time and efficiency saver.