• Bhagyanagar India Limited

Solar Absorber

Surana Solar Absorber was started in 2006 with know-how technology from National Aerospace Laboratories, under Bhagyanagar India Limited. Integrated manufacturing including all the process under one roof makes the company a low cost manufacturer for: melting copper; manufacturing of sheets and pipes; ultrasonic welding; and black chrome coating. Only the best quality oxygen free copper is used to get superlative quality. The process used for manufacturing the solar absorbers is ultrasonic welding, which ensures high thermal conductivity between fin and tube. Standard size: Fin-T 0.12XW 118XL 1900 mm, and tube –D 12.5XG 0.56XL1921 mm. The company makes other sizes as per customers’ requirements. It uses solar selective coating (Nalsun black chromium), which has high absorptance and low emittance in the thermal region.
The advantages of black chromium coating:

• High colour stability against solar radiation and higher thermal resistance than coloured aluminium
• Higher abrasion resistance than coloured zinc
• Higher thermal stability and abrasion resistance than paints
• Higher resistance against impact and breakage than enamel
• The colour and physical properties of black chromium are not affected by higher temperatures – 200ºC
• Its colour is not affected by ultraviolet light and free from colour change when exposed to sun
• The thickness of the black chromium film can be controlled in such a way that the emittance is mainly controlled by the substrate.