solar vacuum tube

Basic Specifications of single target solar vacuum tube: Coating: Al-N-Al Type Length=1200Length=1500Length=1500Length=1800Glass Thermal Energy Parameter 3.3*10-6/ 3.3*10-6/ 3.3*10-6/ 3.3*10-6/Outer Glass Tube Diameter 47MM 47MM 58MM 58MMInner Glass Tube Diameter 37MM 37MM 47MM 47MMThickness of the Glass Tube 1.6MM 1.6MM 1.8MM 1.8MMTransmission Ratio of the Outer Glass Tube >0.80 >0.80 >0.80 >0.80Length of the Vacuum Tube 1200MM 1500MM 1500MM 1800MMSolar Selective Absorber Coating AL-N/AL AL-N/AL AL-N/AL AL-N/ALAbsorptance (AM1.5) >0.93 >0.93 >0.93 >0.93Emission Ration (80) <0.07 <0.07 <0.07 <0.07Atmospheric Pressure Intensity in Vacuum Jacket P<5*10-3P<5*10-3 P<5*10-3P<5*10-3Stagation Temperature >230 Deg. C >230 Deg. C >230 Deg. C >230 Deg.CHeat Loss Coefficient <0.75W/M2 <0.75W/M2 <0.75W/M2 <0.75W/M2Hail Resistant Ability <25MM <25MM <25MM <25MMMax. Pressure Resistant Ability 0.8MPa 0.8MPa 0.8MPa 0.8 MPa Model no.: Dia. 47 with length of 1500mm. Dia. 58 with length of 1500mm. Dia. 58 with length of 1600mm. Dia. 58 with length of 2000mm.