solar vacuum tube

BAOGUANG manufacturing full ranges solar vacuum tubes,with absorption coating AL/AL-ALN and Cu/Ss-AL-ALN etc.
BAOGUANG VACUUM TUBES TECHNICAL DATA:

Item/Technical data
1500mm
1800mm
Outer tube diameter
47mm
58mm
Inner tube diameter
37mm
47mm
Weight
1.40kg
2.10kg
Glass thickness
1.6mm,1.8mm available
1.6mm, 1.8mm available
Material
Borosilicate Glass 3.3
Borosilicate Glass 3.3
Absorptive coating
AL/AL-ALN
Cu/Ss- AL-ALN
Vacuum degree
P<5X10 -3 Pa
P<5X10 -3 Pa
Thermal expansion
3.3X10 -6 /°C
3.3X10 -6 /°C
Insolation Temperature
>200°C
>200°C
Absorptance
α≥90%
α≥93%
Emittance
ε≤ 7.5%
ε≤6 %
Heat loss
<0.6-0.7W/(m
2
°C)
<0.4-0.6W/(m
2
°C)
Maximum strength
0.8Mpa
0.8Mpa
Resist cold
-35 °C
-35 °C
Resist hailstone
Ø 25mm
Ø 25mm
Resist wind
30m/s
30m/s
Start-up temperature
≤ 25°C
≤ 25°C