Oxydro - 17-5-2005 at 18:52
Does anyone know what temperature a stove element can reach? They're cheap, relatively durable, easy to use... I think they could be engineered
into furnaces.
I've been looking at designs for liquid-salt electrolysis, and I want to build a complete unit -- no sitting it on a hotplate, it has to have
heating built in and it has to be well insulated for economical operation.
For now, all I know is that an element *can* melt the little tab atop a pop can, which I believe is relatively pure aluminum. However, when I dusted
some table salt on it, the table salt wouldn't melt like it will in a propane flame.
BTW, I found that's a neat trick if you have trouble with a flame you can barely see - get a bit of salt on the torch and it'll make the
flame bright sodium yellow.
Magpie - 17-5-2005 at 20:32
If you want a rough idea of the temperature of your stove element compare its heated color to a chart of metal color vs temperature. I think this
chart should be available on the internet or in a chemistry & physics handbook.
12AX7 - 17-5-2005 at 20:52
I've heard of stove elements being used in heat treating kilns (up to 1800°F or so). Can't promise anything about life.
Tim
chemoleo - 18-5-2005 at 06:19
Please, let's use Celsius or even Kelvin when appropriate. 1800 deg F means very little to most here, and the scientific community
rarely if ever uses those units. Besides, you'll have to use it too if you ever do a degree ...
Here is a nice table that correlates colours to temperature, it might give you an idea. Even with a F-conversion, which is perfect for training
purposes 
sparkgap - 18-5-2005 at 08:09
Some engineers still tend to report quantities in English units (right, Magpie? 
), so deprecation isn't going to be effective anytime soon. I must agree though that most of us here are more comfortable seeing temperatures in
Celsius or Kelvin. 
BTW, for those lazy to convert, the temperature Tim gave was ~1255 °C.
On the topic, maybe the salt didn't melt because the particular stove you used doesn't heat up well?
sparky (~_~)
12AX7 - 18-5-2005 at 14:24
982.2°C actually, might as well be 1000°C. Orange to yellow hot. I'm used to doing my metalwork in farenheit so farenheit be what I post.
Conversion to C shouldn't be a problem for most people...(just a few keystrokes for me to know more accurately than a SWAG).
I don't have a hotplate, but it doesn't seem to suprise me that it was unable to reach 800°C (salmon red/almost orange) and melt the salt.
Tim
Magpie - 18-5-2005 at 14:42
All chemical literature, procedures, etc seem to be in SI units. And I would think most all of the scientific instruments and measuring
devices would use these units also. So for scientific work and discussion I agree that SI is most appropriate.
In engineering work, such as with ventilation, CFM is most common in the US for airflow. Again one tends to use the units of his measurement
equipment. But in an international forum such as this I try to present both English and SI for such engineering work.
Oxydro - 18-5-2005 at 15:24
Probably heat loss prevented the salt from melting. According to the chart Chemoleo linked to (thanks, really nice) there is no way the element
surface isn't hot enough to melt it. NaCl, melting at 800C, should require only "dull cherry red" and stove elements easily top
that... will edit in a few with my elements' color.
I think that Imperial should definitely be eliminated. But that's hypocritical - I use it myself far too often. I am trying to improve though
EDIT: I think my stove reaches at least midway between cherry and orange red... maybe full orange-red .. so 1000 and 1100 C.
Also, I tried out some more table salt (the pan beneath the element is getting interesting: food, salt, solder, aluminum... at least). I sprinkled
some salt on, watched, nothing.... wet some more into a thick paste and dabbed it on. Still nothing... I put a pot lid over it and went to read some
other posts. I didn't want to leave it too long so I went back in a minute... no salt. Oops. So it does melt. Now I have a reflective, glazed
element. Oddly enough, more salt paste that I added melted right away, even after the element was off and cooling down. I guess the molten salt
"wetted" it and helped transfer the heat.
[Edited on 18-5-2005 by Oxydro]