solar vacuum tube Three targets

Structure	All-glass double-tube co-axial structure
Glass material	High borosilicate 3.3 glass
External pipe diameter and thickness	Φ=58±0.7mm &=1.6mm
Internal pipe diameter and thickness	Φ=47±0.7mm &=1.6mm   Φ=58±0.7mm &=2.0mm
Pipe length	1800mm
Absorber Material	Aluminum，copper,stainless steel
Absorptive Coating	SS-CU-AL-N/AL
Absorption Coefficient	α≥0.92
Emittance	<8% (80℃)
Heat Loss	<0.8W/ ( m2℃)
Vacuum tightness	P≤5.0X10-4Pa
Maximum Strength	0.8MPa
Idle sunning property parameters	Y=260~300m2.℃/KW
Solar irradiation for obtaining a preset water temperature	H≤4.7MJ/m2(Φ58)	H=3.7~4.2MJ/m2
H≤3.7MJ/m2(Φ47)	H=2.9~3.2MJ/m2
Single Tube weight	2.0kg
Wind Resistance	30m/s
Freezing Tolerance	-30 ℃
Hail Resistance	¢ 30mm hail
Insolation Temperature	250 ℃
Average heat loss coefficient	ULT=0.4~0.6W/(m2.℃)
Life Time (years)	15 years

 
 Three targets solar vacuum tubes advantages
1. Greatest advantage: the use of advanced coating technology magnetron sputtering. To ensure that the absorption rate of the film higher than the lower launch.
 2. By the end of the metal layers of copper for the launch lower.  Higher thermal efficiency.
3. The absorption layer of high temperature pipe, stainless steel instead of aluminum ion, and more heat. 
4. Interference film in the temperature rises, the emission ratio changed little.
5. Sandwich vacuum higher, up to 10 (-4) level. 
6. Selective absorbing coating with high coverage, heat, insulation effect.
7. Super Anti-cold: advanced vacuum process, 450 ℃high temperature for up to 60 minutes of strict exhaust, vacuum up to 5 * 10 (-4) Pa, cut off radiation convection heat, better resistance to cold, below zero 40 ℃still work.
8. To avoid the common water heater vacuum tube attenuation of long-term performance of air drying and other issues, longer life.