Paper presented to the 1st International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Kruger Park, 8-10 April 2002.
An experimental investigation is described in which an
experimental set-up and measuring technique is developed. It is
used to evaluate a permanent magnet for the decrease of scale
formation in tubes. The volumetric flow rate is used as the
indicator of scale formation, which relies on the basic principle
that the friction pressure drop increases if scaling takes place.
The test section consists of three soft drawn copper tubes in
which water with a velocity of ± 2 m/s flows. One of the tubes
is used to evaluate the Physical Water Treatment (PWT) device
and the other two tubes are used as a control. With the
experimental set-up described it is possible to detect a change
in the friction factor of 1% which represents a flow rate change
of 22 m f !min. Experiments are conducted in different phases
in which the PWT device is attached onto one of the tubes and
then removed to determine if any change in the scale formation
rate takes place. It follows from the results obtained that a very
sensitive experimental set-up was designed and built with
which very small amounts of scale can be detected. However,
contradictions in the experimental results makes the set-up
unusable for the evaluation of the efficiency of PWT devices.