Anti-scale water treatment devices EUV Antica++


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Physical Treatment of Hard Water

The dominant components of supermolecular structure of any ground-spring water are calcium (Ca2+) and hydrogen carbonate (HCO3-) ions which result from the decomposition of calcium carbonate (CaCO3) according to the following simple equation:

The hardness of water increases with the number of these ions. Based on the same, but reversed, equation, hard water can be softened by separating calcium back to the solid phase (CaCO3). This process occurs, for example, in boiling hard water. The well-known incrustation (see Figure A providing a view from an electron microscope) is formed at the phase interface and suspension is formed in the liquid phase - at a greater distance from the phase interface. Water softening requires a certain amount of power, either heat power, mechanical power, or electric power. The lowest consumption, and therefore the highest efficiency of (CaCO3) separation, is achieved by electric power, which makes it possible to reverse the course of the above-mentioned reaction. The quantity of electric power must be, however, sufficient to maintain the thermodynamic water balance!!! Consequently,

  • (CaCO3) molecules (suspension) are formed in water; in open systems, these molecules are washed away (see Figure B providing a view from an electron microscope).
  • The liberated carbon dioxide (CO2) in combination with water can dissolve old incrustations, which is accompanied by water hardening!
  • If water treated in this way is not consumed within the specific period of time (24 - 72 hours), the process of (CaCO3) molecule decomposition starts and returns everything to the original pre-treatment state. The length of the period depends on water alkalinity and concentration of released carbon dioxide. Water with lower alkalinity returns sooner to the original pre-treatment state than water with higher alkalinity. This fact must be taken into account!

Any supermolecular structure of water described by a complete chemical decomposition contains not only Ca2+ and HCO3-, but also Mg2+, Na+, Fe2+,..., cations (in lower concentrations, though) and SO42-, NO3-, Cl-,... anions. The cation-anion proportion guarantees the mutual balance of their total positive and negative charges under stable conditions - the law of electrochemical neutrality. The electric conductivity of water depends on the total concentration of cations and anions as electric current carriers. By implication, if electric current is produced in hard water of a particular anion and cation concentration, which sets these cations and anions in motion (analogically to Brown motion in water heating), in all probability it results in the highest number of mutual collisions of ions of opposite charges, and the subsequent separation of the highest number of, chiefly, CaCO3 molecules within the liquid phase. This process is determined by the reversed equation for the above-specified chemical reaction. All in all, this results in the maximum efficiency of the whole process!

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