Abstract
The heat exchanger, especially shell & tube type, is basical appratus for heat transfer equipments in various industrial and district fields. The metal tubes, such as cupper, steel and so on, are usually employed in shell and tube heat exchanger. On the other hand, PFA tube using in this exchanger have many advantages that are stable against chemical solution, prevent to get rust, etc.. However, heat exchange efficiency is low value, since PFA has lower thermal conductivity than metals' one. If the conductivity of PFA tube is improved by mixing high conductivity powder in it for example, the effective thermal conductivity of tube may be more larger value and its means bring about large benefit on energy resources.
From this standpoint, we developed the apparatus to measure the thermal conductivity of the thin tube. The data on pure PFA tubes having different 3 sizes diameter are obtained and compared with the data taking from the same dia. tube mixed carbon powder. It is clear that the conductivity of mixed tube have grater value about 1.6 times than pure PFA tubes. Therefore, these mixed tube may be take many improvement to heat exchange coefficient.
