Estimation of 1000w heating element contact temperature

[thydzik]

Hi All

I recently purchased a 1000w heating element for coffee cups,
http://www.ebay.com.au/itm/110668421004
that I will be using on a 240v AC source.

I would like to know if a cup out of silicone will withstand direct contact with the element?

From what I am reading normal silicone can last at about 200 deg C, RTV silicone possibly 300 deg C.

I have read 240v AC will boil a cup of water in 3-4 minutes, 110v AC will boil a cup in 15 minutes. If this information helps.

 

[Naty1]

Almost certainly it will get a LOT hotter than 300 degrees...I'd bet close to a thousand degrees at the bottom of the cup...but the actual prediction depends on how fast heat is lost from the cup which depends on the heat conductivity of silicone and the cup, the surface area of cup,etc,etc and even the surrounding temperature of the room. With a cold enough room, the silicone might never get very hot.

I assume you are making coffee with an element that big, not trying to keep coffee warm. That's a lot of heat.

I have a 17 watt candle warmer next to my computer and that keeps my coffee warm while I fool around here on physicsforums! It's small power is helpful as I forget to shut it off as often as not!

 

[thydzik]

thanks for the quick response,

I am starting to think I may have bought a too high power element.
thinking it would save boiling time.
Yes, I am trying to boil water.

lets assume about 350L (12oz)

what do you think a 500W element's temperature would be?

what I was initially planning on buying is this silicone cup
http://www.byocup.co.uk/