Chemical Engineering - Heat Transfer - Discussion
Discussion Forum : Heat Transfer - Section 1 (Q.No. 13)
13.
With increase in porosity, the thermal conductivity of a solid substance
Discussion:
11 comments Page 1 of 2.
Ashiwani Bharti said:
1 decade ago
We all know that porosity depends upon resistance. It means if will porosity increases, resistance will also increases. And other side we know that conductance is reciprocal of resistance. So in this question porosity increases then resistance increases and conductance decreases.
Amrita Battula said:
1 decade ago
Though presence of pores may increase the surface area, conduction is a solid phenomenon. Thus, the pores do not add to conductivity. Moreover, these spaces cause obstruction between adjacent solid particles and reduce thermal conductivity in an overall.
Ritik gupta said:
7 years ago
I think chemical bonding between the molecules of this material is not much strong. And increased the temperature. It could not conduct heat for a long time. So the thermal conductivity of the porous material decreases with increase in temperature.
Akash Patel said:
1 decade ago
A porous substance may contain gases such as air in the pores- which have low heat conductance and act as insulators, so porous substances conduct heat poorly hence they are used as heat insulators.
(1)
Akash said:
1 decade ago
@Rohan you are incorrect. With increase in gap contact resistance increases as conduction is made difficult. Example plastic- bad conductor because it is porous.
(3)
Arjun patat msu said:
7 years ago
Conductivity is inherent property of material. It will remain unchanged. Conduction will decrease but conductivity will be same.
Zafar said:
1 decade ago
Porous solid has gape b/w adjacent particles this decrease the substance conductivity.
Atul said:
1 decade ago
By increasing porosity conduction space will be more so increasing conductivity.
Rajiv said:
9 years ago
Yes, you are right @Akash.
The conductivity decreases with more pores material.
The conductivity decreases with more pores material.
Rohan said:
1 decade ago
As gape increases contact decrease that leads to increase in conductivity.
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