Paper presented at the 9th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Malta, 16-18 July, 2012.
Fouling of heat exchangers is a prevalent operating
drawback in many industries. Efficient chemical inhibitors
have predominantly been used for many years to combat
deposit formation. Nevertheless new stringent
environmental legislations limit their utilization. In the
present experimental study, two spherical type projectiles of
different sizes and hardness have been used to clean the
inner surface of a single heated tube which was subjected to
the deposition of calcium sulphate. Projectiles were then
injected at different time intervals of injection of every 2, 5,
10, 15, and 30 minutes. The experimental results show that
i) the projectiles would expedite initial nucleation of
crystals even if they are soft and easy to propel inside the
tube and ii) fouling can only be mitigated if the projectiles
exert a shear force that its corresponding removal rate is
greater than the net rate the deposition.
