Efficiency evaluation of cavitation heat generator used for desalination of saline solutions

Abstract

Nowadays, the issue of efficient desalination and treatment of seawater for its further use in various domains of human activity is of much interest worldwide. There are plenty of known treatment techniques. This research paper discusses the method of hydrodynamic cavitation treatment in a heat generator in various modes and proves the performance efficiency of this method. The process of treating saline solutions of different concentrations and registration of electric conductivity of solutions are studied. The possibility of changing the concentration of salt in the solution by treating it in a vortex cavitation heat generator is undertaken. The efficiency of the cavitation process depends on the temperature of the working environment: with the temperature increase, the desalination intensity decreases. Two possible scenarios of the process are revealed, i.e., the decrease in the concentration of salt in the solution or its increase in the presence of a salt source. When working on depleted solutions with a salinity of 1÷5 ‰ at high temperatures, the reverse diffusion of previously adsorbed salts from the internal surfaces into the solution takes place. When working on solutions of elevated concentrations in the same high-temperature range, the reverse diffusion decreases and at a salinity of 67 ‰, its effect ceases, since the concentration of salts on the inner surfaces becomes comparable to the concentration of the solution. The hypothesis of centrifugal separation of salts from water is experimentally proved.