| 摘要 |
<p>Solar water pump comprises a transparent tank allowing solar radiation to vaporise a thin film of a light insol. volatile prod. floating on the water in the tank. The film is rendered black so that variations in pressure of the vapour between day and night expel the water under pressure during the day, while at high condensn. of the volatile prod. causes a redn. in pressure which draws the water by suction from a well to which the system is connected. The volatile prod. is pref. rendered black by colouring, by flotation of a black body of specific gravity less than that of water, or by inserting between water and film a flexible black membrane which avoids direct contact with either, and which has a porous surface for contg. the volatile prod.</p> |
