Furnace Temperature

What is a WK coil?

It all depends on the KWs that you need to heat up and maintain (find out the losses) and also the volume of the furnace, heating rate, expected packing ratio etc.

dear friend, sorry that is KW ( kilo watt). i already blocked all air flow. the silicon blanket is 1260 degree, put 2 lair of that and 2 lair of 6 mm asbestos from all side. inner space is 10" X 10" X 15". in that place i put a crucible ( 13" L 10" outer diameter) is that for enough to blocked the loss of heat? i want to mace the heat 15 min to 20 min. my working temperature is 1450 degree. thank you subhajit

What is inside the crucible? is it not possibble to Induction heat rather than the resistant heating? Your furnace size is very small. may be Induction heating will be much better, but then is it a one time job or regular?

I will just give some formula,

Convection Heat loss Kcal/sqm/hr = 2.3* (skin temp-ambient temp) ^1.25 approx

radiation Heat Loss

= 4.88*Emissivity *((Skin temp+273)⁴ - *(Amb temp+273)⁴) *10^-4Kcal/sqm/hr

Overall you may take, assuming your skin temp is 20-30 deg above ambient to be 250Kcal/sqm/hr

This will be almst negligible considering the size of furnace and the amount of insulation you are putting on.

So use the heat required to raise the temperature.

you may have other losses through the air interaction through furnace etc.

dear friend, the inside materials is non-conductive. that is my regular process. in that chess can i use the induction process. if yes then tell me how can i make and use it. i hope it is less consumption electric power. thanks subhajit

I like this one better - waaaaay more informative than the OP.

dear sir sorry that is kw(kilo watt) thanks subhajit