The all-glass vacuum heat collection tube adopts a single-ended opening design, which is sealed by ring-shaped melting of the inner and outer tubes at one end, and the other end of the inner tube is a closed hemispherical round head. The spring clamp is used to support the round head on the cover glass tube. The inner end of the inner glass tube absorbs solar radiation and the temperature rises, the glass round head forms a free end of thermal expansion, thereby buffering the thermal stress caused by the open end of the vacuum collector tube when the water heater is working;
After the vacuum tube is heated, the trace gas (mainly water vapor) that was originally adsorbed on the tube wall will be released, which affects the degree of vacuum. The getter and the getter film are used to absorb the released gas. Maintain a high vacuum in the collector tube.
