Trying to make a kiln

[Lahearle]

TL;DR Summary

For kanthal wire, what is the MINIMUM weight/wattage needed to achieve 2600 degrees fahrenheit?

Trying to make a kiln and it needs to be "tiny" Plugging this into a regular american wall outlet and I can't have it pulling 10KW.
I need to heat it to 2600 F and I am using kanthal(FeChrAL) wire.

The specific heat at max temperature is supposedly 0.800jg/c
I currently have a wire wound roughly 300 times that weighs 0.05 grams.
(Again, this is a tiny kiln, I am doing things in this that may/may not be explosive and don't want a huge explosion)

So I am wondering, what is the absolute minimum wattage required to reach 2600F? Will it be able to reach 2600F if the actual mass is only 0.05 grams with 400ish watts?

Enlighten me please.

 

[Lahearle]

Also the formula Td = (Pxt)/(MxC) read that 1200 watts at 1 gram = 1350celcius, is this a reliable formula?

 

[Baluncore]

The highest temperature will be reached when the heat loss from the kiln, is equal to the heat radiated into the kiln by the hot wire element.

The power needed to raise the temperature to 1425°C, (2600°F), will be determined by the quality of the insulation you employ.

Insulation is the material you must select. You must compute the minimum thickness of insulation required.

 

[Lahearle]

0.3 W m-1 k-1
past 1000 celcius jumps to
3 W

I have probably less than one third a meter of total area so that makes it
roughly 600 degrees loss?
So I need roughly 1875c or (1200x1)/(0.8x0.800) where 1200 is wattage * 1 in seconds / Grams * specific heat?

 

[Lahearle]

Also, I'm using kaolin clay with no other insulator except maybe sand

 

[berkeman]

Welcome to PF.

So I am wondering, what is the absolute minimum wattage required to reach 2600F? Will it be able to reach 2600F if the actual mass is only 0.05 grams with 400ish watts?

What do you find when you survey the kilns of your physical size? What input power ratings do they show? If you build the insulation (including the access port) in a similar way, you should be able to achieve those input powers.

And I'm guessing that those typical kilns on the market have a "UL" symbol on the label at their AC Mains power input (assuming you are in the USA). That means that they have passed the UL safety approval process, and were designed to UL safety standards for AC Mains powered devices. What is your background in designing and building AC Mains powered devices? Can you say some of the things that you need to do to design and build this kiln to the applicable safety standards?

 

[gmax137]

Have a look at this:
https://www.engineeringtoolbox.com/overall-heat-transfer-coefficient-d_434.html

 

[berkeman]

I did a Google search on kiln specs and got lots of helpful hits. Here is one:

https://bigceramicstore.com/pages/info-ceramics-kiln_power

With rare exception every home/residence in the USA will have 120 V and 240 V single phase power available. Industrial/commercial locations (and sometimes schools) will have 120 V as well, and well as either 240 V or 208 V power, in either a 3 phase or single phase form. (Some industrial locations might even have 480 V power.)

Only very small kilns (less than 1 cu ft) can operate on 120v power (normal household voltage). There just isn't enough power available on 120V circuits to heat a larger kiln. If you want a larger kiln, you will need to identify a 240 V circuit to use, or have a new circuit installed.

<<snip>>

PLEASE NOTE:

This is intended to be a guide to selecting a kiln and understanding the power available at your location. It is not to be taken as an authoritative or definitive document. If you have any concerns or questions about the circuits in your location, please consult a qualified electrician and your local electrical codes before plugging in.

 

[Vanadium 50]

this that may/may not be explosive and don't want a huge explosion)

Poor Fawn Liebowitz.

Making a wire smaller means its surface to volume ratio goes up. Not down. ThaT means the reactivity with the air goes up, not down.

 

[berkeman]

I am doing things in this that may/may not be explosive

Wait, I missed this part. What exactly will you be heating in this kiln?