How does fouling affect the overall heat transfer coefficien

How does fouling affect the overall heat transfer coefficient and hence, the heat transfer rate in a heat exchanger? How do we account for it?

Solution

Solution:

Fouling is nothing but accumulation of unwanted materials in the surfaces on the equipment which we use where any mode of heat transfer will take place.

SO fouling materials generally have lower thermal conductivity hence they have lower overall heat transfer coefficient (in turn means more resistance to the heat flux) which effects the heat transfer from the particular equipment. If we take heat exchangers into account it will also reduce the effectiveness of the heat exchanger.

How do we account for it?

there are many things we can do but we have to take care while designing the heat exchanger especially with the complexity of heat exchange. That is, if the heat exchanger is complicated other than shell and tube fouling is prone to take.

Also if the foulign has already accoured there are many processes for removal of the materials deposited.