Jump to content

Real-Time Kiln Advice (Kiln Curently Firing)


Recommended Posts

  • Replies 173
  • Created
  • Last Reply
Guest JBaymore

Ohmyword, I'm confused again.  I thought that if I bought a high-pressure regulator, I'd have to switch the orifice.  But if I went low-pressure, I wouldn't.

 

You are not "connecting the dots" in the conversation.

 

You are correct in that statement.  The MRs and the pilot currently are set up with orifices for whatever pressure Marc Ward decided you are to be using.  I am ASSUMING that is the 11" WC. that the regulator he supplied to you should output. If in question... contact him.

 

You have to now weigh the potential benefits of changing to high pressure gas versus the "hassels" and costs of changing over.  You'll also have to replace the low pressure guages you now have.

 

Hummmmm............. What regulator do you have from running the B-2 burner on high pressure?

 

best,

 

.................john

Link to comment
Share on other sites

This is the regulator on my B-2 burner.  It's a Chen Fong CF103.  I've found little information about it, but one particular Web site lists it as "Inlet Pressure : Max. 250 PSI 

Outlet Pressure : 0-60 PSIG "

 

b2_regulator.jpg

 

From what we have read thus far, it seems as though we should give it a go as a low-pressure system with a new regulator.

Link to comment
Share on other sites

Guest JBaymore

I don't know that one off the top of my head either.  No time to search now. 

 

Did Marc Ward sell you that one?  If so... check the capacity (BTU / hour or CF / hour).  Just so you know if that one is an option for you should you ever decide to go to a high pressure system.

 

best,

 

...............john

Link to comment
Share on other sites

that is a high pressure regulator-heres the info

http://www.tgas.org.tw/mem13/product_e.asp?cid=2926

I have spent a lot of time goggling regulators in this thread-I hope you get this fixed

 

If you use this on your low pressure burners you will need a different office-they are really cheap -call Marc and have him mail you two of them -you can also buy a number drill set and drill out blank ones but thats may be more than you want to do.

Mark

Link to comment
Share on other sites

Guest JBaymore

No throughput BTU capacity info on that page Mark C. .  That's the missing piece of info.  If she decided to go HP.... I was wondeirng if she already HAS what she needs there.  So maybe no need to buy a new one.

 

best,

 

................john

Link to comment
Share on other sites

Have you considered the option of two supply cylinders with two regulators supplying one line  with a control valve leading to your burner?

Set the regulators to a slightly higher pressure than needed  and use the valve to throttle delivery down to your requirements.

 

Just a thought

Lockley

Link to comment
Share on other sites

Have been working with Marc.  I will be receiving next week a new regulator and necessary connectors to string together an additional two 100-lb tanks.  If the four tanks don't give me a reading of more than 5.5 on the pressure gauge, I'll switch out the regulator.  If that doesn't help, I may be switching to high pressure.

Link to comment
Share on other sites

  • 2 weeks later...

Hooked up the four tanks, kept old regulator:  Same reading on pressure gauge - about 5.2.  (Marc expected 7-8.)

 

Replaced old regulator with new:  Pressure gauge reads 6.4 with one burner running, drops to 5.8 with both running.  

 

Marc has explained that the gauges should not drop when turning on an additional burner - and that it does do this, it indicates a volume issue.  He is trying to avoid switching me to high pressure, saying I've already spent too much money, and switching to high pressure would be much more.  But currently he has no ideas for me, other than using one regulator per burner.  But he wants me to fire it this way before trying the two-regulator option.

 

I'm currently trying to track down two retired ceramics professors who apparently live within 1/2 hour of me.  Because I'm not attempting this again alone.

 

I have to say, building a little wood-fired kiln (that Manabigama is so cute!) is looking better and better every day.  (With the given that I'd actually help fire someone else's before building my own.)

Link to comment
Share on other sites

Just in case anyone is hanging on the edge of their seats:

 

I spoke with numerous potters; no one was willing/able to help me.  So I gave it a go alone again.

 

The temperature stopped rising at 2175 (an additional two tanks and new regulator gave me 200 degrees!  Woo!) - I held there for quite a bit, then shut it down.  I reached anywhere from Cone 4 to Cone 6.  Still that same flame that just goes through one shelf and out the flue.  Still only one shelf with any reduction.  I used twice the amount of soda as I had in the past (2 kg in this 19 cu ft kiln), and there's really no evidence of having added more than before.  I believe the majority of it is going up the chimney (which, at that point, is less than 1" open at the damper).

 

In any event. This system, I believe, is fried. Done.  The amount of heat radiating from the two burners - and the gauges just behind them - is absurd.  I can't fathom the inter-workings to be still functioning properly.  (The heat in the burners is almost immediate upon lighting, as that blue flame is in the throat [but not to the orifice].)

 

Currently in the Frustrated stage, scheming about building a wood kiln.

Link to comment
Share on other sites

Guest JBaymore

Kristin,

 

God I wish I was nearby.  What likely gave you the 200 degrees is the higher pressure on the downstream side of the (still) crappy (cheap) regulator.  More BTU/hr available.

 

IF that burner system is putting out about 200,000 BTU/hr when the system is fully cranked up, you should be able to FILL that chamber with the products of combustion and have the flame front burning off in the base of the chimney.

 

If you can't get that kind of situation to happen when the kiln is at about 1700 F or so (create 'backpressue' with flames licking out of every crack and crevice in the kiln)......... we are likely right back to the burner setup.

 

Still could be your adjustment.... but it is not sounding that way to me.

 

best,

 

..................john

Link to comment
Share on other sites

speaking of basics please refresh my memory on how many cubic foot your interior is (the whole space)

Our 24 cubic salt kiln  is run on 4 MR100 burners (they do not have much reserve left when firing-like none)

Its also natural gas a tad less BTUs than your propane and the presure is 1/4 #.

 

I'm thinking you are still under powered with those regulators

The 4 tanks will help you down the road so do not get bummed out.

Hey is the snow gone yet and is the outside temp above 50 degrees in daytime?Now that the days are getting shorter?

Mark

Link to comment
Share on other sites

  • 2 months later...

Howdy, guys.

 

I have just returned from a firing workshop at Watershed Center for the Ceramic Arts.  We fired two propane-fueled Venturi-burner downdraft kilns, one with salt.  Phew, did I never need that experience.  I have such a better understanding now, of so much.  Too much to mention.  But yes, I believe I had been focusing too much on turning up the burners instead of fiddling with the damper and waiting.  And now I understand what a reduction atmosphere looks like, when peering into the kiln.

 

Really, though, I don't think I have been doing that much wrong.  I really believe it's a burner issue.  Simply the heat coming off of them is enough tell me sum'n ain't raight.  I could grab hold of those burners at the workshop, even at the height of the firing.  I can't touch mine within seconds of ignition.

 

Here's what I would like to do:  Re-build my kiln so that it's a proper downdraft, sized to run on two B-2 burners, situated on either side of the chimney.  (As I already have one, and the high-pressure regulator, etc.)  It's 19 cu. ft. right now.  I'm guessing I'll need to make it about 2/3 of this size? (Unsure as of yet how to do the specific calculation; looking for a formula for BTU requirements with my 3" thick IFB walls.  Will figure it out though.) 

Having run through various scenarios (including turning the kiln on its side - which would make it front-loading - making the now-walls shorter, then building a sprung-arch top), I'm wondering if I couldn't just do this:

Leave it just how it is, but move the far wall (the one that now has burners) closer to the chimney, however many inches to get the cu. ft I need.  Does this make sense?  Just re-build that one wall, making the kiln more box-shaped than its current rectangle shape.  This would leave part of the roof and various metal parts of the kiln hanging out there are the end, but I think otherwise the concept will work?  I'd have a little 29"h x 27.5"w x Y"d flat-topped downdraft kiln.

Would love to hear comments on this, the latest of my hair-brained ideas.

Link to comment
Share on other sites

In case that wasn't clear - here, let me make it even less clear.  This is my idea:

 

26.jpg

 

The lid would still sit on the metal frame, there would just otherwise be empty space over there on the right. 

Important to note:  I understand I need to build a proper kiln; no more of this conversion craziness.  But it appears we are moving - far, far away - next summer.  I want to stick with this one until that time, when I do build a proper kiln (from someone else's plans!) at our new home.

Link to comment
Share on other sites

Guest JBaymore

Yes... those cheapie MR burners are not working correctly...... said so all along. 

 

However....... instead of changing things immediately..... maybe take the new understanding you have about firing process from your watershed experiences....... and try firing it one more time as is.

 

best,

 

..................john

Link to comment
Share on other sites

Use whatever are the most powerful burners you have

 

(I believe I had been focusing too much on turning up the burners instead of fiddling with the damper and waiting)

 

I only turn my burners up a few times and then the whole fire is with the damper adjustments after 1800 degrees -and very few of them as well.

​Having a digital pyrometer tells you that the kiln is climbing or stalled or cooling

Mark

Link to comment
Share on other sites

Guest JBaymore

We talked earlier in this thread (or one of the other related ones) about the fact that damper adjustments can be VERY fine changes....and make all the difference in the world.   Given you new knowledge base.... I'd also say go back and re-read everything that has been discussed in all of the threads on this kiln.... with a new set of eyes.

 

best,

 

.....................john

Link to comment
Share on other sites

Guest JBaymore

Not with those MRs. Not worth the effort.

 

Even with a blower... no retentionm nozzle that works.  Adding air would just cause them to fluff out..... and at low settings they'd stuill backburn.

 

You could build power burners with some black iron pipe easier and even make a more effective retention nozzle.

 

best,

 

.................john

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.