Vacuum tube is an integral part of solar collector. Vacuum tube is the same as the traditional Dewar (vacuum) bottle.

Vacuum tube is an integral part of solar collector. Vacuum tube is the same as the traditional Dewar (vacuum) bottle.it  contains two borosilicate glass tubes. Outer layer of the inner tube coated with solar selective coatings. One end of inner tube connected with the outer tube, the other end sealed with the outer tube. Between Inner tube and outer tube of the annular space is vacuum mode,through the  conduction and convection to reduce the heat loss.

Features: energy transform efficiency, low heat loss the stability of advanced coatings, up to 380 centidegree. 15-year warranty perioda high degree of vacuum in a cold climate to ensure the normal operation.

Model type 47×150 58×180 weight 1.35±0.12kg 2.29±0.18kg Structure All glass coaxial double-layer tubes All glass coaxial double-layer tubes Outer tube diameter 47±0.7mm 58±0.7mm Inner tube diameter 37±0.7mm 47±0.7mm Outer Tube thickness 1.6±0.15mm 1.8±0.15mm Inner tube thickness 1.6±0.15mm 1.6±0.15mm Tubes length 1542±4mm 1812±4mm Material of coating AlN/AIN-SS/Cu AlN/AIN-SS/CU Absorptance 0.94~0.96 0.94~0.96 Emittance 0.04~0.06 0.04~0.06 Vacuum P≤5×10-3pa P≤5×10-3pa Transmittance of Outer Tube 0.91 0.91 Stagnation temperature (height) 270~300 270~300 Heat-loss coefficient ≤0.6w/m2* ≤0.6w/m2* Bearing hailstone ability hailstone diameter25 hailstone diameter25 Pressure-endure ability 1MPa 1MPa

three high tube