1st tuyeres

[Szakallas1]

I wanted to do something different.  Not trying to reinvent the wheel.  Just wanted to try something different.  I've not tested it yet.  

I'd still like to figure out a way to put some refractory mortar on the front of it.  I've never used refractory mortar so I don't know how sticky it is or what happens after it gets hot.  Does it shrink, or crack?

I have no idea how long I spent on this one.  But when my little girl saw it she immediately took spoons to it and rung it like a bell.  When it started maki g different pitch sounds she said "It's mine now Papa".  I sighed. Said ok. And began making the next one that I'll put in the next post.  It's just mild steel.  This one is 316l. 

[Steve Sells]

how does that work as a tuyere?

[Szakallas1]

Well...I was going to weld it to a stainless steel water tank.  But since my daughter confiscated it I now have a different one. 

It still needs to work done to it also.  Like the 1st, I'm welding it to a water tank made of sheet metal.  Still would like to cover the front with some refractory mortar to keep it lasting longer.  Will it work?  I guess I'll have see.  I can't think of any reason why it wouldn't though.

I still need to fill in that empty space on the side.

I guess I did already.  

[Irondragon Forge ClayWorks]

I will guess that you are going to use them in a side blast forge...yes.

[Szakallas1]

Yes

[Frosty]

A couple thoughts. WAY too complicated a build! You do realize a water bosh is to conduct heat from the flame face and shed it as quickly as possible. Yes? Making anything BUT the part in contact with the fire from anything thicker than absolutely necessary is counter indicated. SS for anything but the flame face is also a poor choice there are much better conductors of heat ad you want the bosh to radiate heat.

If you're orienting the tuyere in the pic the way you intend in the bosh you're wanting cold water to flow uphill into the tuyere. sloping the top upwards is good but make the bottom nearly level with the bottom of the bosh, just enough above the bottom to catch debris and not interfere with flow. Smooth bottom so it's easy to scoop clean. 

As built the bosh will have a large reservoir of nice cool water that can't get to the tuyere. The warm water will stratify on top and circulate without mixing significantly. This is why you want the tuyere at the bottom so the coolest water is drawn in to replace the warm water convecting up and out. Make sense?

Refractory mortar is meant to stick to things but I don't know about smooth SS. Maybe if you run some chicken . . . track (PG, rules you know.) weld beads to give the flame face some tooth for it to stick to. Tacking some expanded metal would be pretty positive. 

That's darned fine looking work though.

Frosty The Lucky.

[Szakallas1]

 

9 hours ago, Frosty said:

A couple thoughts. WAY too complicated a build! You do realize a water bosh is to conduct heat from the flame face and shed it as quickly as possible. 

I know. I know.  I should've just kept it simple.  But I have this itch sometimes to go the long way around to get to somewhere, instead of taking the direct route.  That's just how I'm wired. 

I guess I just thought if opened up the bottom more to allow colder water in with less friction faster (is that even the correct terminology?),  and opened up the top to allow the heated water in the nozzle to escape faster, than the natural thing that would take happen is a cooler tuyere.  Hopefully it'll work.  

9 hours ago, Frosty said:

As built the bosh will have a large reservoir of nice cool water that can't get to the tuyere. The warm water will stratify on top and circulate without mixing significantly. 

This would be a total failure.  Why would the water do that?  Why would the tuyere not have access to the cooler water?  Heck.  I figured it would make it easier for the water to cycle.  Instead of a pipe that only juts out of the bosh,  it's now a a larger flayed square tube.  Please forgive the crude drawing. 

So if it doesn't work....well... nothing ventured nothing gained I guess.  

The stainless steel one that I made first was confiscated by my little girl.  It becoming a lawn ornament that she can play music on.  I've got to stick the air supply tube in a rock for weight. 

[Szakallas1]

Um. I think I'm gonna read "Anatomy of a simple side blast forge" today.  I just saw it. 

[Frosty]

If you look at your drawing, the cool water (blue) is flowing up hill which it wont without a strong draw.

The colder the water the denser, yes? And energy always takes the path of least resistance. So the warm water from the tuyere rises and cool water sinks making a horizontal vortex. Upward closest to the fire where everything is warmest, down on the far face of the tank and it's being drawn to the upflow in the tuyere. Now why doesn't it mix naturally with the coolest water in the bosh? Because it's cooler and densest while the water returning down the back of the bosh is warmer. The easiest path for the circulation is not to force it's way into denser water and displace it upwards. The easy path is to angle towards what's drawing water, the engine, which is the tuyere. 

If however the tuyere lays horizontally at or near the bottom of the bosh with an upwards angled top like yours the cool water at the bottom has to flow into the tuyere so the descending water flowing along the back of the bosh has to fall all the way to the bottom, across and into the engine. This also has the benefit of keeping the water flow in strong contact with the tank wall for maximum radiation.

Hmmm?

Frosty The Lucky.

[Szakallas1]

Not trying to beat a dead horse here.  Thanks for your patience.  Much appreciated. 

[Latticino]

Think of it this way.  You want the coldest water in the bosh in contact with the face of your tuyere that is closest to the fire ball.  You also want the face of the tuyere a certain set distance above the bottom of your solid fuel, at the correct angle.  Which of the three diagrams you made optimizes this?  I do like the second one down from a fluid flow perspective, though I'm sure it is more difficult to fabricate.

[Szakallas1]

I've had to read over Frosty's and your post a few times.  It's starting to make sense.  I think.

My brain was so convinced that giving the tuyere a more open access to the cold water at the bottom was good.  So if I understand you guys right, with the design opened up at the top and bottom it messes with the circulation.  The cooler water falling from the top of the water line back down to the bottom of the tank will not displace the colder water at the bottom. It would be pulled in by the tuyere "the engine" over top of it instead.  That's fascinating to me.  Hard to accept.  But kinda cool nonetheless. 

Oh well.  I planned on building a 5 tuyere forge anyway.  I'm just getting good practice I guess.  The next ones should've take as long.  So scrap the bottom "ramp", but go ahead with the top? 

[Frosty]

I think you've got it now. Sketch #2 is the better plan for maximizing flow.

The circulation in sketch #3 wouldn't flow to the bottom of the bosh, the majority of the flow would be above a layer of cooler (darker blue) water laying on the bottom. It's very similar to a weather pattern inversion layer. The circulation in a bosh is quite weak, slow, making the cool layer in the bottom stronger by comparison so intermixing is minimal, mostly from friction at the boundary layer. 

Before I discovered how hard it is getting good smithing coal here I did a lot of thinking and sketching about water cooled forge blasts. One of the things I considered desirable was easy servicing and had one design with an easily replaceable nozzle. That one finalized, before I dropped it as a futile exercise, with a water jacket ending in a through fitting threaded to receive pipe from the inside rather than outside and tapped overly deep. This allowed an over threaded pipe to be screwed in from the tank side far enough to screw a pipe cap on the fire side. The cap was drilled for the air blast.

When the fire face of the tuyere was too damaged to serve it would unscrew, if the threads were too damaged to unscrew from the cap a little tie with a hack saw left clean threads to unscrew from inside the tank. 

I won't get into different baffle plans I came up with to maximize flow patterns in the bosh. OR cooling fins on a copper backed bosh. I felt the easy way to make a nozzle was to form the last 4" or so from castable refractory and forget the rest.

Of course that was up until I discovered the only good coal available for an affordable price was go dig it yourself coal. I had an effective propane forge and oxy propane torch so I shelved the brainstorming. It was fun though.

Frosty The Lucky.

 

[Szakallas1]

This is fun.  Those are all great ideas!   I read on one of your posts that you mentioned a gas forge that had an entire cavity that was essentially a ribbon burner.  Now that sounds cool!  A challenge I hope to see you undertake.

I will probably start thinking of ways to incorporate some of the ideas you mentioned.  Not to steal them.  I had previously contemplated a replaceable tuyere myself when I decided on a side blast forge.  Being a welder I deal with consumables on a daily basis.  Hopefully you'll be one to appreciate the outcome of the efforts.   

Thanks for your help guys.  I should have something fabricated by next weekend.  

Side note: 

Is there any benefit to a stainless steel tuyere and bosh?  I know that the water in the bosh made with steel turns red from the iron.  I don't think it continues to rust from the inside out.  I don't think Fe is like that.  It doesn't oxidize the same way it does when it's water like it does when it's exposed to atmospheric conditions.  I really don't know, so if I'm wrong please correct me.  So if the water isn't really the determining factor, then the ability for the stainless to withstand higher temperature without affecting the integrity might be helpful.  Would it make it last longer?  

My real goal is to make a tuyere that will last longer and easier to change out.  It can't be that hard.