Evacuated Vacuum Tube

Each Evacuated Vacuum Tube consist of two glass tubes made from extremely strong borosilicate glass The outer tube is transparent allowing light rays to pass through with minimal reflection, The inner tube is coated with a special selective coating (AL-N/AL) which features excellent solar radiation absorption and minimal reflection properties, The top of the two tubes are fused together and the air contained in the space between the two layer of glass is pumped out while exposing the tube to high temperatures, This "evacuation " of the gasses form a vacuum, which is an important factor in the performance of the evacuated tubes

Evacuated tube basic specifications :
Length(nominal) : 1500mm/1800mm
Outer tube diameter : 58mm
Inner tube diameter : 47mm
Glass thickness : 1.6mm
Thermal expansion : 3.3*10-6A C
Material Borosilicate : Glass3.3
Absorptive Coating : Graded Al-N/Al
Absorptance : >92%(AM1.5)
Emittance : <8%(80A C)
Vacuum : P<5*10-3Pa
Stagnation Temperature : >200A C
Heat Loss : <0.8W/(m2A C)
Maximum Strength : 0.8MPa