Tecnologia mais limpa aplicada ao tratamento de água em sistemas de resfriamento abertos com recirculação

• Autor(a) principal: Pereira, César Augusto
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/15699
• topic: Water; cleaner technology; treatment; Água; tecnologia mais limpa; tratamento; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA

The studies for the use of cleaner technology to water treatment in open recirculating systems lead to the development of a treatment philosophy based on the search of an operation with ideal cycle of concentration. In this way, the material balance control in the cooling system, would be reached a concentration level which the circulating water exhibit naturally, and at the same time, low iron corrosion tendency and low calcium carbonate scale formation. The treatment using corrosion and deposit formation inhibitors would be only a complement, reducing the chemicals addition for the water conditioning. The present work intents to demonstrate that the treatment criteria based only on the stability index do not consider the fact that water-soluble species do not concentrate by the same way, mainly due to conversion reactions involving the carbonate ion and the calcium ion precipitation. To support this work, field tests were done in an open recirculating cooling system during its normal operation, without water chemical treatment. It was possible to observe the concentration variation of each critical species present in the water with blow-down flow rate. The obtained results and the study done showed that the traditional methodology can present deviations from the true values, which may affect the water treatment quality, leading to the use of higher concentration of chemical products for the water conditioning, in an opposite way of the original purpose for the treatment execution within the principles of a cleaner production. This work also emphasize the qualitative and quantitative species relevance, present at the make-up water, on the treatment quality, advising that the water reuse as make-up of a cooling system should be criteriously analyzed, because a low quality water can lead to an impracticable internal treatment, demanding a previous treatment many times economically unviable and causing environmental impacts