DEVELOPMENT OF BRACKISH WATER DISTILLER USING EVACUATED TUBE FOR SUB-SAHARAN COUNTRIES

Nowadays the Sub-Saharan countries are suffering of two crises, the crises of lack of clean energy and fresh water. To resolve these crises many researches on renewable energy and resource of fresh water had been done and still undergoing. The researchers predict promising results. In this work, an experiment is done to resolve these two problems at a time. By using solar energy, a passive water distillation is demonstrated. A solar evacuated tube with a parabolic trough reflector and stainless tube condenser is used. The solar evacuated tube absorbs and converts the solar energy to heat and vaporize the brackish water and the condenser condenses the vapour in to clean water. To increase the performance, the water is filled into the tube thus it has a direct contact with the absorber. The tube is inclined at 36 degree which is the latitude of the site (Ashikaga, Japan) where the experiment is done, to accelerate the bubble formation and vaporization. In addition to this, the inclination helps the vapour to rise up,as water vapour is less dense, and minimises the vapour loss. 0.33kg/sqm.h rate of production and 27.1 percent efficiency is obtained. With the results obtained, the solar evacuated tube distiller is effective for the Sub-Sahara countries.