Reduction in the surface tension of water due to physical water treatment for fouling control in heat exchangers

The purpose of the present study was to investigate whether or not a physical water treatment (PWT) reduced the surface tension of hard water. Two different PWT devices were used: a permanent magnet—Drexel University (PMDU) and a solenoid coil electronic device (SCED). The effects of the treatment number of the PWT on the surface tension were studied. Two separate experiments were conducted: one was the measurement of surface tension, and the other was a flow-visualization of dye behavior in water samples. As the number of treatments of the PWT increased, the surface tension of the sample water decreased, a phenomenon that was consistent with the results in the dye flow-visualization experiment.