Kiln still stalling

[neilestrick]

I was thinking about the pressure today, too. It could be that those burners are meant to run on higher pressure. Was there any sort of instruction manual with it? Did the previous owner fire it with the same regulator setup? If there' s a name on the burners, you may want to call Ward Burner and see if he knows anything about them.

[Babs]

6 hours ago, Mark C. said:

Keep in mind she lives on an Island and does not have the same resources of land livers.

Sounds like the burners are starved for air-open the flaps at least some next fire.

Yes or had supply inefficient.

Only time I got backburning into burner was at the beginning when gas flow small ..

Sounds like time for a fishing diving trip to Active Passage Marc and pop in to see Linda's kiln. Water temp should be balmy about now. Freezing current temp doesn't change much. Great fishing west coast of V.I.

[Mark C.]

1 minute ago, Babs said:

Yes or had supply inefficient.

Only time I got backburning into burner was at the beginning when gas flow small ..

Sounds like time for a fishing diving trip to Active Passage Marc and pop in to see Linda's kiln. Water temp should be balmy about now. Freezing current temp doesn't change much. Great fishing west coast of V.I.

Great idea but my arms broke-so fishing and diving is out now. Xmas pots are bisquing now as I will have help glazing.Its going to take a few extra days.

[Babs]

Although you might just get out of that bookwork at end of year!

Thinking re. How far from kiln those burners are sitting.....

[Babs]

Linda can you go  watch see listen another gas firing s.where

I know every kiln is different nut it might just flick a switch in your brain

Just a thought

Cheers.

 

[Linda A]

1 hour ago, Babs said:

Linda can you go  watch see listen another gas firing s.where

I know every kiln is different nut it might just flick a switch in your brain

Just a thought

Cheers.

 

Sounds like a good idea

[Linda A]

2 hours ago, Babs said:

Yes or had supply inefficient.

Only time I got backburning into burner was at the beginning when gas flow small ..

Sounds like time for a fishing diving trip to Active Passage Marc and pop in to see Linda's kiln. Water temp should be balmy about now. Freezing current temp doesn't change much. Great fishing west coast of V.I.

Love you to come by and see my kiln.  A better time would be spring or summer.  We are getting windy rainy weather now. Too crappy for fishing. Are you serious your arms are broken.  Sorry to hear that.  How does some one break two arms.?

[Linda A]

3 hours ago, neilestrick said:

I was thinking about the pressure today, too. It could be that those burners are meant to run on higher pressure. Was there any sort of instruction manual with it? Did the previous owner fire it with the same regulator setup? If there' s a name on the burners, you may want to call Ward Burner and see if he knows anything about the burners

3 hours ago, neilestrick said:

I was thinking about the pressure today, too. It could be that those burners are meant to run on higher pressure. Was there any sort of instruction manual with it? Did the previous owner fire it with the same regulator setup? If there' s a name on the burners, you may want to call Ward Burner and see if he knows anything about them.

No I don't have a manual. Only instructions I had were the firing procedure manual which states the air discs on the burners should be nearly closed otherwise I will get burnback and damage the burners. Yes same regulator setup as previous owner had.

[Linda A]

4 hours ago, Patrick said:

Also, not sure how comfortable you are in messing with the regulators (or replacing them with adjustable high pressure regulators), but a 100 pound propane tank has anywhere between 100 and 200 psi, depending on ambient temps, so you have lots of room here to see if you can get something that works better for you.

 

4 hours ago, Mark C. said:

I like the high pressure regulator idea as well as the tank swap out that Patrick is proposing.

 

4 hours ago, Mark C. said:

I like the high pressure regulator idea as well as the tank swap out that Patrick is proposing.

Which regulator would I have to change. The one at the tank or the one just before the two burners.

The one at the tank just changes the psi from the tank to the line.  It is adjustable and set at around 5 psi.The other one further down the line changes the 5 psi to 12 inches of water column.  Even if I changed the pressure at the tank wouldn't it still be the same coming out of the regulator that measures the 12 inches of water column.

[Linda A]

4 hours ago, Patrick said:

OK. Quick check to see if it's a tank freezing issue.  Take a 20 pound propane tank - the kind you use on a gas grill (borrow one from a friend if need be).  A 100 pound tank should have the same valve as a 20 pound tank.  Fire your kiln with the 100 pound tank until it stalls.  As soon as it stalls, turn the gas valves off, swap to the 20 pound propane tank, and turn the gas back on.  (No worries about pressure differences in a 20 and 100 pound tank.  Propane makes it's own pressure by boiling at -43 degrees Fahrenheit.)  The kiln will be hot enough that it will re-ignite the propane as soon as it enters the kiln. Propane ignites between 920 and 1020 degrees Fahrenheit (Some will say "unsafe" - do what you feel safe with.) Try to finish out the firing.  You should only lose a few hundred degrees in all this swaparoo.  I've shut down the kiln, drove to the store to swap out a 20 pound tank, came back home, hooked it all back up, and only lost about 300 degrees.  If it is a freezing issue, this will let you know for sure.

 

I will have to try that another day but thanks for the idea. Raining and windy, so can't fire.

 

[Linda A]

7 hours ago, liambesaw said:

Make sure the damper is fully open so it doesn't back out of the venturi, when the flaps are open a LOT more volume of air moves through the burner and it needs to go somewhere.  Start with the damper fully open and adjust the venturi flaps and gas.  Definitely sounds like you're not getting enough air moving through to me.  Loud isn't bad, as long as it's the sound of rushing air and burning and not the sound of flames shooting out of the air ports in the venturi burner

I'll try that, thanks.  Have to wait for better weather

[neilestrick]

Did the previous owner have any trouble that you know of?

[Linda A]

5 minutes ago, neilestrick said:

Did the previous owner have any trouble that you know of?

I don't really know. I bought the kiln off a friend of his who had inherited it from him when he died.  His friend was not a potter and didn't know anything about the kiln.  The kiln looked like it hadn't been fired much, looked almost in new condition even though it was manufactured in 2000.  

[Mark C.]

12 inches of water column  is a very low pressure for propane-as I said I'm not a propane guy but 7 inches of water column is  1/4 pound PSI so the 12 inches is less that 1/2 # pressure which seem really low for propane. I use propane in a high volume stove to cook my crabs boil  huge pot of water right now -it boils water also for my salt kiln spray water-I use a high pressure regulator for that-its just a cheap one but I know its more than 1/2 # pressure

A normal house on natural gas is 1/4 pound equal to 7 inch water column. I have a water column gage that you put water in but with my arm broken you are going to have to wait for a true pressure reading on that stove burner

I'm now guessing you have to little pressure (also the burners have their air flaps cranked down to low to compasate for this )

We need a propane guy to answer the pressure issue-you could just call Mark Ward at

http://www.wardburner.com

and ask about the pressure-he will tell you what you need pressure wise in a heartbeat.

If the answer is yes than all your regulators especially the 12 inch WC ones need to be gone or upgraded.I'm wondering why you have 3 regulators as I think one will do for both burners off the tank.

I am guessing you do not have enough BTUs to get that kiln going and if thats the case it can be fixed-I would not fire again until you get the pressure straighten out.

[liambesaw]

Yeah I don't know, I use a high pressure regulator on mine (0-30psi) but I never have had it open up to 30, that would dump the tank pretty fast.  I mean she's getting up to 2000 degrees or whatnot, so 12 inches wc isn't THAT low.  Probably too low if it's backing out of the burners with the venturi open though.

[Linda A]

47 minutes ago, Mark C. said:

12 inches of water column  is a very low pressure for propane-as I said I'm not a propane guy but 7 inches of water column is  1/4 pound PSI so the 12 inches is less that 1/2 # pressure which seem really low for propane. I use propane in a high volume stove to cook my crabs boil  huge pot of water right now -it boils water also for my salt kiln spray water-I use a high pressure regulator for that-its just a cheap one but I know its more than 1/2 # pressure

A normal house on natural gas is 1/4 pound equal to 7 inch water column. I have a water column gage that you put water in but with my arm broken you are going to have to wait for a true pressure reading on that stove burner

I'm now guessing you have to little pressure (also the burners have their air flaps cranked down to low to compasate for this )

We need a propane guy to answer the pressure issue-you could just call Mark Ward at

http://www.wardburner.com

and ask about the pressure-he will tell you what you need pressure wise in a heartbeat.

If the answer is yes than all your regulators especially the 12 inch WC ones need to be gone or upgraded.I'm wondering why you have 3 regulators as I think one will do for both burners off the tank.

I am guessing you do not have enough BTUs to get that kiln going and if thats the case it can be fixed-I would not fire again until you get the pressure straighten out.

No I won't be firing again for a while.  Weather is too crappy.  I am going to call mark Ward and see what he says.

[neilestrick]

Take a look at the burners and see if there's a brand name cast into the housing. Ward will want to know that.

[Linda A]

24 minutes ago, neilestrick said:

Take a look at the burners and see if there's a brand name cast into the housing. Ward will want to know that.

Ok Thanks

[High Bridge Pottery]

The easiest way to know what pressure you need it to find out what size orifice is in the burners.

I have been dubious about the constant pressure regulator since the start but I am still confused on how you ended up with propane burners on a natural gas regulator if that is the case. If you were just using propane with a complete natural gas setup it seems that it would make the btu more not less.

[PatIsGone]

16 hours ago, Linda A said:

Which regulator would I have to change. The one at the tank or the one just before the two burners.

The one at the tank just changes the psi from the tank to the line.  It is adjustable and set at around 5 psi.The other one further down the line changes the 5 psi to 12 inches of water column.  Even if I changed the pressure at the tank wouldn't it still be the same coming out of the regulator that measures the 12 inches of water column.

If it were me, I would take the 12" WC regulator off and leave it off and replace the one at the tank with an adjustable high pressure regulator.  You're firing manual anyway, so it's not like you won't be watching it.  Talk about being able to fine tune your pressure and your air flaps... it'll be a whole different level of control.  I think you'd appreciate it. BUT (and it's a big but!) the quicker you let the fuel out, the quicker a tank will freeze up.  Ergo, on you next firing, have a 20 pound tank on hand.

If you do an Amazon search for "adjustable high pressure regulator propane", you'll get a good idea of what you're looking for. 

Also - was thinking of this today at work - regulators can freeze up also.  Does either of your regulators get icy? Not just cold with condensation, but icy?  That can also put a kink in the works.

 

EDIT: If the 5 pound is adjustable, just take the 12" WC one off and see what you can do.  No purchase necessary.

[Babs]

Well with a smaller kiln I used to go above 5psi on glaze firing. If replacing the one on the tank make sure your line can take the greater pressure.

I'd up the pressure coming from tank and place a regulator and pressure gauge near the burners.....after ma king sure the airflow into kiln is sufficient...distance of burners from kiln, air "flaps "on burners  open.

But tempting as these things are...adjust one thing at a time

The hours Linda is having to fire for is OTT IMO

[Rex Johnson]

Gee, alotta posts since I was here last. Read it all.

A few things I pickup on and can only give comparisons...

First is the freezing tank.  Anytime freezing happens pressure drops as mentioned, and it usually means it's getting low on fuel. Wondering if 100 gallons is big enough. Seems like it should be. Mine is a 250 gallon.

On the WC, I run both kilns on 9.5 successfully, in fact for the first time last weekend I fired both kilns at he same time to cone 6-7, albeit I started the big kiln, got to 1500-ish then stated the other (already candled for 2 hours) then turned down the gas and held it at 1500,  until the first kiln reached temp. Once that was done I fired the other up to temp. Started candling at 8AM, was finished by 3:30PM. 'Big" kiln interior is appx 3'wide X 3'tall x 2'deep, downdraft. Smaller kiln is your standard Olympic 2827G updraft with 4 venturi's.

"Flaps" you do have venturi burners, not forced air. Yes? Mine is forced air (2 burners both sides at the back, same side as the chimney). that is, two 2" burners with Sticktite tips with squirrel cage blowers.  There is a brick flue (9"x9" inside) running up the back the height of the kiln and a 4' steel duct lined with 1/2" fiber atop that.  The good thing about forced air burners is the flow they help  to swirl the heat across and UP (target bricks), and then hopefully sucking down towards the flue. I actually haven't ever seen two large venturi's but doesn't mean it doesn't work.  Most kilns I've seen using venturi's have either burners coming in equally form the sides or the bottom.

Seems there may be several things going on. Lack of fuel, maybe too much draft, maybe the flue size itself. I didn't see here, is it a commercial kiln or home built?

 

[amanda b]

hi linda, 

sorry I'm so late to the party. as it happens, I have a slightly larger estrin downdraft that provides me, the Oregon Potter community and everyone who knows me with no end of frustration and funny tales. 

fun facts about estrin I've discovered on this journey: they're out of business because they made bad kilns. according to the guys at geil who have been incredibly generous for literally no reason whatsoever considering I do not own one of their kilns... they've helped me to understand that estrin basically ripped off their kiln designs,poorly. 

so while at base what you have looks like it should fire like a normal kiln... it's a box with a damper and there's fire.... you're going to have to start ignoring everything everyone tells you because they have no idea how to deal with an estrin, and you're going to have to ignore all common sense. 

I've had some of the same problems you have. you are welcome to contact me off the site. amanda@ceremonyclay.com. what I will say is that it's been a great little kiln to really dig in with and there will be a part of me that is sorry to see it go someday. but it will be a very small part. 

[Bill Kielb]

I think I read most of these and to solve this we need to see the burner (s) 12” W.C. At the burner orifice may be a lot or very little. Many propane burners run in the PSI range. 2.31 feet = 1 PSI so it takes nearly 28” of water column pressure to equal 1 PSI.

first things first, show me the burner, tell me the orifice size and oerating pressure and we go from there. If you can create 1/2 million btu then we can talk. If you can only create 100,000 btu then first place might be to straighten out the burners so you can reach temperature.

just out of curiosity if you set your downstream regulator to max out at 16” W.C. What is your result. The energy entering your kiln will increase exponentially with pressure but your losses up the chimney and through radiation also increase exponentially as temperature rises.

The one flaw in the ointment, I have no idea if your burners are atmospheric or powered. Either way increasing the gas delivery will only increase the heating into the kiln if we do not go into reduction. Once we begin to starve our gas flame for oxygen thermal output decreases even though we are adding gas. Like flooding an old automobile.

Is it a supply issue or loss issue or both? Easy trial - raise your gas pressure maybe 16” to the burner, blue flame and what is the effect. Open the damper enough to keep it out of reduction. Are you gaining temperature or losing it?

In all cases we need to know the pressure at the burner. It tells us how much work the burner can or is doing.

[Bill Kielb]

On 10/23/2018 at 8:31 PM, Linda A said:

No I won't be firing again for a while.  Weather is too crappy.  I am going to call mark Ward and see what he says.

Good idea! I am guessing Mark would love a picture and any info on the burner you can give him. (Just a suggestion) We often use his orifice  tables along with others for burner approximation. One last note that I picked up on for you to explain to Mark. It was your comment about the discs. My guess is these are primary air shutters and leaving them nearly closed will make this burner very inefficient. He will definitely be able to help you quickly resolve  this.