High Efficiency Solar Water Heater Solar Vacuum Tubes

1.Vacuum tube feature:       The kind of vacuum tube assimilate the advanced 12 layers of spattering deposition of trivalent element technology, high quality borosilicate glass 3.3, gradual change of CU-SS-ALN/ALN selective absorption coating and make vacuum tubes have high performance of absorptance and low reflection ratio. Through interlayer, vacuum has a unique effect of thermal, with its temperature up to 380 degree of idle sunning, performing a strong ability. 2. Vacuum tube specification:      47-1500MM, 58-1800MM (Standard specification)      47-1800MM, 58-2000MM (optional specification)  3. Vacuum tube Loading quantity in container:        47-1500MM, 4700 PCS/20ft, 9600 PCS/40ft.       58-1800MM, 2860 PCS/20ft, 6600 PCS/40ft Specification:StructureAll-glass double-tube co-axial structureGlass materialHigh borosilicate 3.3 glassExternal pipe diameter and thicknessdia.=47±0.7mm  &=1.6mm    dia.=58±0.7mm  &=1.6mmdia.=70mm  &=2.0mm   Internal pipe diameter and thicknessdia.=37mm  &=1.6mm    dia.=47mm  &=1.6mmdia.=58mm  &=1.6mm   Pipe length 1500mm 1600mm 1700mm  1800mm1900mm 2000mm Absorptive coating propertyStructureAL/AL-ALN(H)/AL-ALN(L)/ALNSediment methodSingle target magnetron sputtering platingSpecific absorptionas=0.88~0.91(AM1.5)Emission ratio0.05~0.075(80°C±5°C)Vacuum tightnessP≤5.0×10-³PaIdle sunning property parametersY= 220 ~ 260m²°C/KWSolar irradiation for obtaining a preset water temperatureH≤4.7 MJ/ m²H=4.1~4.4 MJ/ m²H≤3.7 MJ/ m²H=3.1~3.4 MJ/ m²Average heat loss coefficientUlt=0.6~0.7W/( m².°C)    /* March 10, 2023 17:59:20 */!function(){function s(e,r){var a,o={};try{e&&e.split(",").forEach(function(e,t){e&&(a=e.match(/(.*?):(.*)$/))&&1