Please see Fig.5, that is floating head type heat exchanger. Only
one end of channel is connected with shell by flange, called
stationary end. The other end of tube sheet is not connected with
shell but slid relative to shell, called floating head end.
Therefore, thermal explosion of pipe bundle is not restrained by
shell in this kind of heat exchanger. Thermal effect doesn™t appear
because of differential expansion between shell and tube bundles.
Advantages: The tube bundle can be withdrawn in order to clean pipe
and shell pass conveniently. Temperature difference among the
medium can™t be limited. It can work under high temperature and
high pressure. Generally, temperature and pressure are separately
no more than 450„ƒ and 6.4MPa. It can be used in the situation that
the dirt is very heavy and the tube side is easy to be corrosive.
Disadvantages: The flange connecting area between floating head
cover and tube sheet is quite large, so that the diameter of shell
increase, and the annual channel with small resistance between tube
bundle and shell is formed. Part of fluid will pass here and don™t
take part in the heat exchange process. The disadvantage includes
complex structure; high metal consumption, high cost. Above
advantages and disadvantages indicate that the floating head type
heat exchanger can suit the condition of large temperature
difference between pipe and shell , high causticity of shell side
medium and scale formation easily . It can be applied widely
although it has complex structure, high metal consumption and high