concrete and gunite

[gelsi]

hi
what is conductivity ot concrete and gunite at 730°C? (or high temperature near 730)

i must estimate the thickness of insulation for a drum where conductance has to be < 22.7w/m2°C (because of PSV requirement to use a low coefficient F)
and after 90 minutes fire temperature is 978°C and it's need vessel surface temperature must be < 250°C, so average T is about 730°C

Anyone has a prompt or a comment to my approach?

 

[IRstuff]

Lots of numbers; very little description/explanation

TTFN
faq731-376

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[gelsi]

i must define insulation thikness of equipment fire-insulation:
Tmax equipment metal surface is 250°C
T-fire after 90 minutes of fire event is 978°C
conductance of insulation layer has to be < 22.7 w/m2°C

simple calculation with assumption of plan layer follows:
s > kavg@cond/22.7 [m]
kavg@cond is average conductivity at conditions
s is tickness of plan layer of insulation
condition is Tavg = (978+250)/2 = 614 °C (with cauton consider higher temperature 730°C)

i do not know k @ avg condition and i would know if that simple model is good for you

i hope it'clear now

bye

 

[willard3]

Sounds like homework to me..........

 

[dvd]

Take a look here:

http://www.bnzmaterials.com/pdf/I-D-C-GM.pdf