Effect of flow velocity on the surface fouling

الملخص EN

The flow velocity is one of the most important parameters affecting the fouling rate on the heat transfer surfaces.

An experimental study is carried out to investigate the effect of flow velocity on the surface fouling for the particulate fouling type.

The experiments are carried out under constant surface temperature by using the steam as a heating medium.

Water with a solid particle concentration of 1 gm / lit is used as a test fluid and the test flow velocities are ranged from 0.24 to 1.42 m / s.

The runs have been operated for a long time period (about 200 hrs) to attain the asymptotic fouling resistance.

The obtained experimental results showed that ; increasing the flow velocity decreases both the fouling resistance and the asymptotic fouling resistance.

The delay time is very small and it seems to be zero.

The saw tooth effect has been obtained in all runs.

There is a great effect of flow velocity on the fouling resistance due to velocities in the range from 0.24 to 0.35 m / s where this effect is seen to be smaller when the flow velocity increases from 21.1 to 42.1 m / s.