Alimentação de caldeiras industriais por água de chuva: uma análise da viabilidade técnica e econômica

Abstract

The water can be considered as a limiting factor for the industrial development. In Brazil, for example, there was the culture of we are the country in the world with more availability of potable water and we not learn how to manage our water properly. This mismanagement can compromise their quality, spending much more with treatments such as flocculation, softening, demineralization and active filtering. Rainwater can be considered a great alternative source, because their capture and storage provides good quality water for industry and also prevents flooding. One of the equipaments that consume more water in industry is the boilers, in addition, the quality of the water to the boiler’s feed requires special care and this make the rain water a good solution. The parameters that were evaluated for the water quality in this work were: Turbidity, Total Hardness, Dissolved Oxygen, Hardness Calcium, Electrical Conductivity, Hardness Magnesium, Total Dissolved Solids, Total Acidity, pH, alkalinity, chlorides and Total iron. The potentiometric methods, volumetrics of neutralization titration by complexation, and instruments were used. The economic viability was done with data collected in a big food industry, present in the state of Sergipe and was used the models of discounted cash flow, Net Present Value (NPV), Internal Rate of Return (IRR) and Payback Period Discounted. The results obtained in general, show in the rainwater an alternative source of high quality and that can reduce the costs with treatments for industrial water. They also show that the water captured by the direct method presents greater purity than that captured by the indirect method and in general both have parameters below the recommended limit for use in boilers, needing only some preliminary treatments. Economic analysis shows that it is a viable method over an estimated 20-year period. This study aims to contribute to the reduction of consumption of fluvial waters, which are of high drinking potential, and to increase the use of rainwater that has excellent quality for industry and low potential for human consumption.