It is a common sense that the scale from the water dispenser may lead to health problem and the magnetized water has a certain scale inhibition function.Permanent magnets are easier to install with lower cost for scale inhibition of drink water comparing it to the solenoid with electric current twined the water pipe for scale inhibition of industrial fluid.We fix a set of permanent magnets on the outer wall of cool tank to generate constant magnetic field inside the tank.The magnetic flux density distribution in the cylinder tanks by both magnets and solenoid is simulated and compared with COMSOL Multiphysics software.The experiments prove the correctness of the theory that magnetic field imposes Lorentz force on the free ions in the water(abbr.Ion Theory) and also charged particles(abbr.Particle Theory).Meanwhile

Lorentz force on charged particles is much stronger than the free ions.Constant magnetic field may slow down the production of CaCO3.Under the ambient temperature

the scale inhibition rate reaches as high as 29%.Under the condition of long-term heating up the water

the permanent magnet group has a better scale inhibition effects comparing with the blank group.Finally

we calculate the concentration of each component in the tank based on the data of pH value and calcium concentration.We use the concentration of CaCO3 to calculate the scale inhibition rate which is difficult to measure.