Internal Surfaces
Initial water used in power system, for various reasons a large set of corrosive properties that contribute to the formation of scale and deposits on the inner surfaces of the heating equipment (boilers, heat exchangers, pipe heating systems, etc.), contributing to the development of corrosion processes of metal. The rate of scale formation of carbonate increases depending on the hardness of raw water, and operating time of heat exchange equipment. The resulting scale deposits in pipes and boilers, reduces their heat output, increasing the coolant flow rate (fuel consumption, depending on the thickness scale: 1 mm. – 4%, 5 mm .- 15%) increase the temperature difference and, consequently, damage to pipes. Scale deposits in pipes and shell and tube heat exchangers (boilers) that are widely used in heating, leads to an increase in steam flow and as a consequence, reduce the efficiency by 30-50% due to a significant reduction in the intensity of heat transfer. Throughout the world, the urgency of this issue is extremely important and is reflected in the Fifth and Sixth Framework Programmes with the release of the European Union Up to 14% of funds from the general budget, ie 2 billion Euro per year. The mechanism of the formation of scale due to hard water of crystallization is mostly dissolved calcium carbonate in the form of calcite. The driving force crystallization process is the supersaturation, ie, excess of the actual concentration of the crystallizing substance above its equilibrium concentration in the circumstances. Crystallization consists of two stages: the formation of crystal nucleation and growth to a visible size.
