2mm thickness solar vacuum tube

1,Solar vacuum tube for solar energy water heater 2,ISO,CE 3,Available in various size 4.5days delivery 5.OEM available

1, Vacuum tube is consists of two layer of glass tubes2, ISO900:2000, CE certificate;3, 0.91 transmittance of outer tube

4, The outer tube is made of extremely strong transparent quartz sand which can resist impact from hail up to 25mm in diameter.

5, The inner tube is also made of quartz sand, but it is coated with a special selective coating with strong heat absorption and lowest heat loss.

6, The air is evacuated from the space between the two glass tubes to form a vacuum, so it  eliminates heat loss.

7, This why the tubes are able to absorb the energy from infrared rays which can pass through clouds.

8, So it also can operate in low temperature and low sunlight medium.

 

MODEL ITEMS	GB(single target)
Configuration	Double-layer concentric boronsillicate glass tubes
Glass thermal expansion coefficient	3.3*10-6/	3.3*10-6/
Diameter of outer tube	47±1mm	58±1mm
Diameter of absorber tube	37±1mm	47±1mm
Thickness	1.5mm(±0.1mm)	1.6mm(±0.1mm)
Transmittance of outer tube	0.91	0.91
Length	1500±5mm	1800±5mm
Solar selective     absorbing coating	Al-N/Al	Al-N/Al
Absorptance(AM1.5)	≥0.89	≥0.89
Emittance	≤0.0880	≤0.0880
Vacuum	P≤5*10-3Pa	P≤5*10-3Pa
Stagnation parameter	≥230/KW	≥230/KW
Average Heat loss coefficient	≤0.85W/(*)	≤0.85W/(*)
Solar irradiation under stagnation	≤3.5MJ/	≤3.5MJ/
Hailstone resistance	hailstone diameter25mm	hailstone diameter25mm
Pressure-endure ability	0.6mPa	0.6mPa

2mm thickness solar vacuum tube