Features of All-Glass Vacuum Tube / Glass Tube Fuse

Our All-glass Vacuum Tube is made of dual borosilicate glass tubes, the space between the two tubes is evacuated. The AL/N/AL selective coating on the outer wall of the inner tube absorbs sunshine and transforms it into heat which in turn heats the cold water in the inner tube. When the water in the tube is heated, its density will decrease and will go upward into the tank; Meanwhile the cold water in the tank will flow down into the tube due to its greater density. Thus, the circulation and heat-exchanging in the system is completed. The color of the inner tube is black-grey. This vacuum tube has a high heat-efficiency and low price. It is suitable in areas with winter temperature above below zero 20º C.

Standard: (1)Φ 47mm, Length 800mm/1200mm/1500mm/1600mm/1800mm/1900mm/2000mm/2100mm
(2))Φ 58mm, Length 800mm/1200mm/1500mm/1600mm/1800mm/1900mm/2000mm/2100mm
(3)))Φ 70mm, Length 800mm/1200mm/1500mm/1600mm/1800mm/1900mm/2000mm/2100mm

Technical specifications

Item name	all-glass vacuum tube
Structure	All-glass double-tube co-axial structure
Glass material	High borosilicate 3.3 glass
External pipe diameter and thickness	dia. =47± 0.7mm  & =1.6mm       dia. =58± 0.7mm  & =1.6mm dia. =70± 0.7mm  & =2.0mm
Internal pipe diameter and thickness	dia. =37± 0.7mm   & = 1.6mm       dia. =47± 0.7mm   & = 1.6mm dia. =58± 0.7mm   & = 1.6mm
Pipe length	1200mm 1500mm 1600mm 1700   1800mm 1900mm 2000mm 2100mm
Absorptive coating property	Structure	AL/AL-ALN(H)/AL-ALN(L)/ALN
	Sediment method	Single target magnertron sputtering plating
	Specific absorption	a s =0.90~0.93(AM1.5)
	Emission ratio	0.05~0.075( 80  º C ± 5  º C )
Vacuum tightness	P ≤ 5.0× 10-³ Pa
Idle sunning property parameters	Y= 220 ~ 260m²   º C /KW
Solar irradiation for obtaining a preset water temperature	H ≤ 4.7 MJ/ m² (dia. 58)	H=4.1~4.4 MJ/ m²
	H ≤ 3.7 MJ/ m² (dia. 47)	H=3.1~3.4 MJ/ m²
Average heat loss coefficient	U lt =0.6~0.7W/( m² . º C)
Service life	more than 15 years