Resultados prelimares de um novo protótipo do dessalinizador térmico com recuperação de calor e aquecimento direto por gás natural

Abstract

The objectives of this article are the development and the operation parameter studies of a new thermal desalination unit, directly heated by a controlled natural gas burner. The unit was designed and built to allow steady state operation with predetermined temperature in the salty water tank and to help the study of its operation parameters. The unit has six stages, a storage tank, a heat exchanger to cool the condensation surface, burners, and a natural gas supply system with controlled pressure and temperature. Two types of burners were used: circular and pipe. The experimental measurements include temperature in the storage tank (evaporation surface), in the heat exchanger (condensation temperature), and the natural gas, salty water, and condensed (produced) masses. The parameter studied in this work was the level of water in the tank. This level is associated with the amount of heat stored in the unit, which influences the start of production after the burners are turned on as well as after they are turned off. The tank is 0,27m wide, 0,52m long, and 0,10m high. It was observed that a 3 liter mass of water in the tank presented the best results, with a production of 1,39 liters in 2 hours of direct heating and in 1 hour with the burners off. The average temperature in the tank was 92ºC and 42ºC in the condensation surface.