Abstract
A direct solar still with multi-effect thermal diffusion was developed by Oriental Metal Manufac-turing Co., Ltd.in 1978.It has much higher efficiency than the ordinary Basin type still.
However, there has been brought about a very difficult problem due to the serious corrosion ofits evaporator consisting of piled-up metallic plates. Therefore, a test was carried out under the simulated evaporating environment with hot saline water, and 17 kinds of metallic materials resistant to corrosion were selected for this purpose.
In the test, the outside of metallic sample plates was heated by infrared ray tube, and the saline water heated to 80-90°C was made flow slowly in the wick placed on the reverse side of the sample plate.
The results of this corrosion test showed that only three samples were resistant to corrosion in the finite test duration (5,800-6,400h), and the same result was obtained in the field test of this direct solar still made in Okinawa Island.
