EFFECT OF GALENA POWDER OF 63 ?m MICROMETER, PARTICLE SIZE AND LESS ON THE ABSORBITIVITY OF BLACK PAINT MIXTURE

In this article, addition of Galena Powder to black paint has been investigated, as a new selective solar absorber for water heating system. The used powder was prepared from an ingot of Galena, which was found to be almost about 85wt% of lead, 9wt% of sulfur, and some of other elements. Selective surfaces; pure aluminum, black paint, black paint with different percentage of Galena powder 5wt% , 10wt%, 12.5wt%, 15wt%, 20wt% w ere experimented. The results of this research showed that the maximum value of temperature has been achieved at about 10wt% of Galena with black paint. The temperature difference was around 6.5 0 C as an average value higher than the case of plain black paint.