A New Technology to Prevent the Formation of Limescale in Hot Water Supply Systems

Abstract

Given that the quality of water supplied to hot water supply systems must meet drinking water requirements, it is also important that the water preparation process is of great importance. The quality of that water is also important in terms of preventing the formation of heat in hot water systems. It is known that the main cause of the formation of water is the presence of calcium and magnesium cations and bicarbonate and sulfate anions in water. The traditional methods for preventing the limescale include the combination of calcium and magnesium cations from the water and replacing them with cations that are not easy to resolve at high temperatures. The quality of water treated by these methods does not meet drinking water requirements. Taking these into account, the Cl-anionizationprocess of drinking water has been developed in high-tech anionite technology. According to this technology, the first water from the city water gridis processed through anionite and activated carbon filters, which are mechanically charged with high anionite. The treated water is then cleaned out of microbes and bacteria through the ultraviolet disinfection equipment and delivered to the operator according to the quality requirements for drinking water. In the chlorine-anionization process, most of the sulfate and bicarbonate anions in water change to chlorine anions and their solidity remains constant. Thus, the density of the limescale-forming anions in the water decreases sharply and it meets the quality indicators of drinking water. High-grade anionite in the filter (8÷12) is regenerated by NaCl solution. The filtration rate of the solution from the anionite is determined depending on the concentration of calcium cations contained in the salt given for regeneration. Regeneration mode is such that the CaCO3 combination does not crumble when the anionite layer is formed. It is known that the temperature of the heated water in the hot water supply system does not exceed (60÷70)°C. In this case, the decomposition of limescale at Hc<2 mg-eq/l (carbonate hardness) is not observed. As carbonate hardness increases to 4 mg/l, the thin layer in the system shows a collapse. The basic element of the proposed technological schemeCl-anionite filter was applied at ADA University in Baku and positive results were obtained. Early observed collapse of pipes has been prevented and the working regime of hot water heaters has improved. A high-performance anionite such as A200EMBCl, which is a major ingredient of the UK's Purelite, and then the Russian-made AB-17-8 high-anionite anions have been used on the device.