Methods of Physical Water Treatment
1. Permanent magnet
Water flowing through a piping behaves like a moving electric conductor of particular geometric dimensions and of specific conductivity. If such a conductor moves in a constant magnetic field, ions are affected by Lorentz force which tries to set them in motion, i.e., to induce electric current. The value of this force is directly proportional to the size of a moving charge, its speed, and the magnetic field induction. If, however, charge speed changes are significant, Lorentz force also changes, which influences the probability of mutual collisions of ions of opposite charges, and consequently, the process efficiency.
2. Inserted power supply
Ions can also be set in motion by voltage connected between two electrodes inserted in water (electrochemical cell or an external power supply). Then, the current is determined by the voltage value and water conductivity. The electrode material must prevent other ions from liberation in order to avoid any violation of the electrochemical water balance and the related process efficiency reduction.
3. Alternating current induction
Another method of setting ions in desired motion is the transformation of alternating current between a coil wound around a piping and water. The coil represents an input winding, the metal piping a short-circuited output winding, and water a transformer core. Foucolt eddy currents are induced in water even if it is not in motion. Eddy currents depend on the magnetic flow magnitude and the electric resistance of water column at the winding installation point. The resistance depends on the piping cross-section, the so-called active length of water column, and water conductivity. If water speed is non-zero, ions are also affected by dynamic Lorentz forces. The maximum water treatment efficiency is preconditioned by adjusting the coil current intensity to:
It follows from the above-given descriptions that the latter method is the most advantageous in terms of maximum efficiency. Moreover, its practical application is the simplest of all the methods discussed. All the three methods require very accurate data of