Freshwater is an essential ingredient for human life. Today, water crisis due to population growth and inadequate freshwater resource has become a global challenge. Therefore, finding alternative water sources for regions with water scarcity is essential. Fog and dew are two main potential source of water in these regions. Over the last decades, fog collection technology considered as an adequate water resource to alleviate water shortage. In this method, fog collector fabrics are erected perpendicular to the wind direction and capture fog droplets. These fabrics could be different in terms of fiber material and weave structure. The objective of this research is to investigate the effects of Coolmax yarn characteristics (such as yarn diameter, monofilaments cross sectional shape( as well as geometry and cover factor of fog collector on the fog capture efficiency. Therefore, the fog capture efficiency of three different Coolmax yarn consisting of fiber with circular, tetra and hexa cross sectional shape in harp and orthogonal structure were tasted. Experiments were conducted at the temperature of 20.0 ± 0.5 °C and the humidity of 75%±2. To eva‎luate fog capture efficiency, the amount of collected water was measured within 30 min. using statistical software, the effects of the cross-sectional shape of the filaments and the structure of the fog collector on the efficiency of fog capture were investigated and analyzed. Results show that the yarn diameter and cover factor and geometry of the mesh structure has the most important role on the fog collection efficiency. In both harp and orthogonal structure, the droplet capture efficiency increased with decreasing the yarn diameter and increasing the mesh cover factor improves the fog capture efficiency. The geometry used in the orthogonal structure caused this structure to have a higher fog droplet capture efficiency than the harp structure through the formation of a water bridge clogged in the holes of the mesh surface. According to the results, although the micro grooves on the monofilaments had no effect on the fog capture efficiency but it has affected the transfer of droplets captured by the collector structure. In the Harp structure, the Existence of longitudinal microgrooves and the increase in their number on the surface monofilaments surface caused the captured droplets to be transferred faster. In the orthogonal structure, the Existence of microgrooves on the surface of the monofilaments has led to the formation of a water bridge clogged on the collector surface and has increased the fog droplets captured efficiency, and also the increase in their number on the monofilaments surface has increased the fog droplets captured efficiency.

محمد قانع

محمد شيخ زاده

مهدي حجازي ، سعيد آجلي