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Kiln Calculator - Would it be useful?


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#1 bellonart

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Posted 13 October 2012 - 02:15 AM

I was wondering... I'm in the process of developing an easy to use web-based tool that will calculate the hours required to fire an electric (computerized) kiln. The calculator is useful in that it can tell you, surprisingly accurately, exactly what time your kiln reaches a desired temperature. I developed this as a tool to easily figure out when I need to close the lid of the kiln...

Can anyone see any other potential uses for this kind of calculator? Or, perhaps, why this calculator wouldn't be all that useful?

----------

The reason I ask is because I learned to fire kilns that needed their lids to be left open until they reached 800 degrees to let out the moisture and other organic materials that fire out of the clay body. This was necessary because the kilns weren't vented, and leaving the lids closed could cause carbon to attach to and damage the elements. Leaving the lid cracked open allows those materials to easily escape. By 800 degrees, the organic materials are burned off and the lid can be closed to save electricity and the life of the elements.

Feedback?

#2 Frederik-W

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Posted 13 October 2012 - 06:52 AM

I think most potters use the same programs to fire all the time, so they calculate it once and thereafter they know.
The potters who change the program usually know how to work it out.
That said, I think some will find it useful.

What I do is I put kiln schedules into spreadsheets to produce a graph, then it is easy to interpret the way the temperature rises,
also it is easy to see when a certain temperature will be reached after start time.
E.g. a graph for bisque, a graph for gloss firing etc.
This graph can be referred to all the time, as long as the program does not change.


#3 bellonart

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Posted 13 October 2012 - 07:01 AM

I think most potters use the same programs to fire all the time, so they calculate it once and thereafter they know.
The potters who change the program usually know how to work it out.
That said, I think some will find it useful.


I figure seasoned ceramicists probably don't need a tool like this, but it might be really useful for people who are super busy and need to calculate a specific time to handle a programmed kiln, or someone who's not good with math and want to make sure they are available to shut a kiln... I think this would be a good tool for a University or community studio setting.

Basically, I'm trying to get more feedback before my site goes live. It's actually up and running now, but I'm still tweaking the design and features. We're also working on a reverse calculation tool where you tell the program when you want to shut the lid, and it tells you exactly when you need to start it.

I'm hoping that other uses will arise from this tool... perhaps experimenting and testing results can be better documented or calculated. Don't know yet...

#4 neilestrick

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Posted 13 October 2012 - 08:49 AM

Personally, I think leaving the lid open is a waste of energy and completely unnecessary for venting moisture. In 20 years of firing kilns I have never once left the lid open. As long as you leave the top peep open, which you should do for the entire firing to let out fumes, there is no reason to prop the lid.
Neil Estrick
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#5 JBaymore

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Posted 13 October 2012 - 09:10 AM

Are you simply using a combination of the programmed "rates of climb" on the various segments and the "desired end point" to project this time? Or are you attempting to model actual kiln performance parameters?

I ask becasue I am working on a similar piece of software that models kiln thermal parameters as well as they can be addressed.

best,

............................john
John Baymore
Immediate Past President; Potters Council
Professor of Ceramics; New Hampshire Insitute of Art

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#6 OffCenter

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Posted 13 October 2012 - 09:11 AM

I was wondering... I'm in the process of developing an easy to use web-based tool that will calculate the hours required to fire an electric (computerized) kiln. The calculator is useful in that it can tell you, surprisingly accurately, exactly what time your kiln reaches a desired temperature. I developed this as a tool to easily figure out when I need to close the lid of the kiln...

Can anyone see any other potential uses for this kind of calculator? Or, perhaps, why this calculator wouldn't be all that useful?

----------

The reason I ask is because I learned to fire kilns that needed their lids to be left open until they reached 800 degrees to let out the moisture and other organic materials that fire out of the clay body. This was necessary because the kilns weren't vented, and leaving the lids closed could cause carbon to attach to and damage the elements. Leaving the lid cracked open allows those materials to easily escape. By 800 degrees, the organic materials are burned off and the lid can be closed to save electricity and the life of the elements.

Feedback?


Yeah, I think closing the lid during a firing might save a little electricity. Close it at room temp, not 800 degrees.

Jim
E pur si muove.

"But it does move," said Galileo under his breath.

#7 JBaymore

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Posted 13 October 2012 - 09:24 AM

I think the "prop the lid open" business is a persistent holdover from the long history of manual UNVENTED (with local pickup) kilns combined with the business we have been discussing elsewhere here of many students thinking certain things they are taught are RULES that apply to every situation. On older kilns it was hard to keep it under 212F manually, particularly with on/off bank element controls.

In an electric kiln with good local pickup ventilation, propping the lid open serves no purpose and does, as Neil mentions, waste some heat energy. If the work is damp..... simply program in a hold below about 200 F (to allow for any thermocoluple inaccuracy as well as kiln unevenness) for a while to dry it out.

If you don't have a local pickup vent... then that changes things a bit........but not hugely. As Neil said, a single open top spyport will nicely vent out into the room air (which hopefully you then have ata least a small HOOD over the kiln to capture after it exits). But for health reasons it is really not good to simply let stuff vent into the general room air.

If you want truly optimum firings cycles for both energy efficiency as well as the best firing for the quality of a given load of ware, you will have different ones for different types of loads......... damp, bone dry, clay body X, clay body Y, light density loads, high density loads, and so on.

best,

............................john
John Baymore
Immediate Past President; Potters Council
Professor of Ceramics; New Hampshire Insitute of Art

http://www.JohnBaymore.com

#8 Nelly

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Posted 13 October 2012 - 11:34 PM

I think the "prop the lid open" business is a persistent holdover from the long history of manual UNVENTED (with local pickup) kilns combined with the business we have been discussing elsewhere here of many students thinking certain things they are taught are RULES that apply to every situation. On older kilns it was hard to keep it under 212F manually, particularly with on/off bank element controls.

In an electric kiln with good local pickup ventilation, propping the lid open serves no purpose and does, as Neil mentions, waste some heat energy. If the work is damp..... simply program in a hold below about 200 F (to allow for any thermocoluple inaccuracy as well as kiln unevenness) for a while to dry it out.

If you don't have a local pickup vent... then that changes things a bit........but not hugely. As Neil said, a single open top spyport will nicely vent out into the room air (which hopefully you then have ata least a small HOOD over the kiln to capture after it exits). But for health reasons it is really not good to simply let stuff vent into the general room air.

If you want truly optimum firings cycles for both energy efficiency as well as the best firing for the quality of a given load of ware, you will have different ones for different types of loads......... damp, bone dry, clay body X, clay body Y, light density loads, high density loads, and so on.

best,

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



Dear Inventor,

I am not good at math. I have various schedules suggested to me by my cone art dealer. One for bisque, one for glazing at cone 6, one for candling and now one for glazing earthenware. I have learned that I can simply take my cone 6 schedule and substitute the final or highest number into my program to go higher in terms of the range.

While it sounds intriguing, I wonder how it will work with the various kiln or digital software. First and foremost, you will likely have to have good working knowledge of how the kiln works without the old knobs of low/high and the Dawson sitter.

With a digital kiln I have had to use language like "ramps" instead of turn-up times to figure out my schedule. To be honest, I turn the kiln on and simply watch it over the time--in and out into my garage.

One thing I can assure you is that getting a digital kiln is daunting in the beginning. Overwhelming when you are used to the older style kiln. Thus, whatever you do, make it really, really simple. You can add fancier things but ensure that it is incrementally discussed using simple language the average person can understand. For hobby potters their learning is I think if I can speak for others a learning curve. For those taught in a formal classroom, I think it is easier.

I just know after one year with my digital kiln, I am still doing basic things. I anticipate working in this manner until I want to vary something significantly and then I will search out new schedules or timing issues.

Not sure any of this helps but do remember issues of literacy in every sense (i.e., written language, education level and numerical literacy). Without it, it may be too complicated for your widest audience to access.

Some thoughts...

Nelly

#9 lcar

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Posted 15 October 2012 - 02:39 AM

At my local potter's guild, our policies regarding kilns are: they must not be on high overnight, and someone must be there at the end of the firing to make sure the kiln shuts off. Preheats, delays, changing firing temps and ramp rates find us often counting on our fingers to figure out what time the kiln will shut off. Sometimes this is at the end of a long day when the brain has gone home before the body, lol. I can see a calculator possibly being useful for these reasons. Delaying shutting the lid is no longer the norm around these parts as most kilns that I know of, have vents installed. I would be interested to try your calculator, especially if I could use it on my iphone.

Leanna
Leanna Carlsonwww.carlsonpottery.com

#10 Amy Waller

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Posted 15 October 2012 - 04:50 PM

I'm not sure I understand exactly what your calculator would do, but if you're not familiar with it, you might be interested in Orton's Cone Calculation Program. It's an older piece of software, available free from the Orton website. (It's Windows-only as far as I can tell - personally, I would love to have access to something like this that was web-based and/or could be run on more modern operating systems, including ios.)

Here's how Orton describes the software:

The Cone Calculation program was developed by Orton to provide customers with more options for using cones to quantitatively monitor and control firings. This write-up describes the program. If desired, print it for reference. Input cone number, bending angle and firing schedule to determine equivalent temperatures for Orton Pyrometric cones. This program can be used to:

· Determine Cone Equivalent Temperatures

· Find Temperature Differences Between Cones

· Evaluate the Effect of Soak Times


· Determine Appropriate Cone Series


· Calculate Heating Rate that affects cone bending


The program is based on mathematical expressions to describe the behavior of pyrometric cones. The values shown are for Self-Supporting cones. When Large cones are used, the tip should be mounted 1 ¾ inches above the mounting plaque at an 8º angle. If mounted at 2 inches, the cone will bend about 2º C lower in temperature.

You can download it from the Resources page on the Orton website (software download links are on the right side of the page, under "Software Download").


#11 bellonart

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Posted 20 November 2012 - 05:06 PM

Wow, that's a lot of good information! Sorry it took me so long to reply, this project kind of got put on the back burner... It sounds like for the most part it's not super helpful, but maybe someone will find a use for it or maybe something unexpected will surface. I know that I'll use it when I do finally get my kiln installed.

It is intended to be a free web tool, not sure when or if I'll be able to make it an app, but it was programmed to work on an iPad/iPhone in the web browser... we'll see how the webtool works out and I'll make sure to let everyone know when it's available.

Thanks!

~Marcus

#12 bellonart

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Posted 20 November 2012 - 08:57 PM

I'm not sure I understand exactly what your calculator would do, but if you're not familiar with it, you might be interested in Orton's Cone Calculation Program. It's an older piece of software, available free from the Orton website. (It's Windows-only as far as I can tell - personally, I would love to have access to something like this that was web-based and/or could be run on more modern operating systems, including ios.)

Here's how Orton describes the software:

The Cone Calculation program was developed by Orton to provide customers with more options for using cones to quantitatively monitor and control firings. This write-up describes the program. If desired, print it for reference. Input cone number, bending angle and firing schedule to determine equivalent temperatures for Orton Pyrometric cones. This program can be used to:

· Determine Cone Equivalent Temperatures................



Yeah, the calculator doesn't have anything to do with cones. It calculates the time needed to complete a firing schedule and it allows the user to figure out the approximate time the kiln reaches a desired temperature. I used this program in my college studio to determine the time to shut the lid on the kiln, but what I've found out is that most hobbyists don't manually vent their kiln. Either they just don't do it, or they have some kind of venting system installed to where leaving the lid open is not necessary.

I was taught that leaving the lid slightly propped open until 800 degrees can save the life of your elements. Just a few inches... it allows carbon and other materials burning off of your greenware or glazes to more easily escape the kiln and are thus less likely to attach to the elements. This is just what I've been taught... but maybe the added energy cost of propping the lid open negates the benefits.

I just wanted to, more or less, find out if anyone could think of additional uses for calculating the exact time a kiln reaches a certain temperature. ....... Maybe I'm over-thinking this........

#13 bellonart

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Posted 20 November 2012 - 09:07 PM

Are you simply using a combination of the programmed "rates of climb" on the various segments and the "desired end point" to project this time? Or are you attempting to model actual kiln performance parameters?

I ask becasue I am working on a similar piece of software that models kiln thermal parameters as well as they can be addressed.

best,

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


That was not the intended purpose of this program. But I suppose you could use it as such. If you calculated a program to take 16 hours to fire and it took 20, then you'd know something was up. It wouldn't be of much help identifying what the problem was... just that it was there.

Are you familiar with the term "ramps?" The calculator does display the time needed to complete each ramp, so that information could be useful in identifying an issue. Say if everything was fine, ramp 1 and 2 completed on time, but ramp 3 was either way too early or took too long... I guess I'm just not experienced enough to really know what to do with all that information.




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