black chrome coating solar absorber , with ~97 absorption, ~9% thermal emission;it have a great ability to absorb solar energy

material: fins: 0.12/0.15*1840*125/140mm copper parent metal.

                surface process mode: plate selective black chrome coating

                 risers: 1886*10*0.5mm copper pipe

                 header:1060*22/25*0.6mm copper pipe

welding way:

     fins and risers welding: untrasonic welding

     risers and headers welding: copper brazing

    hearder painting and water pressure testing. and finally packing

solar absorbers with black chrome coating