Safe combined degasser capable of absorbing nitrogen

Abstract

The present invention is a safe nitrogen-absorbing combined getter, which includes water-absorbing material, oxidant, and an openable sealed container buried in the water-absorbing material or the mixture of water-absorbing material and oxidant, and the inside of the container is placed The active material that can react with nitrogen to form a solid substance exists in the form of a thin film of ≤10 microns. After the vacuum insulation panel is exhausted and sealed, the container inside the getter can be opened by external force to work safely. Advantages: On the one hand, since the water vapor cannot contact the active material, there will be no H that greatly increases the thermal conductivity of the vacuum insulation panel. 2 produced, has taken up N 2 The active material will not react with water vapor to release ammonia gas. On the other hand, since the active material used to absorb nitrogen is small and exists in the form of an extremely thin film, when the seal of the vacuum insulation panel fails, it will completely react with the air entering the interior, and the safety hazard of the recycling and cutting operation will be reduced. to zero.

Description

technical field [0001] The present invention relates to a safe nitrogen-absorbing combined getter, a getter composition for improving and maintaining vacuum in devices that cannot be heated above 200°C, especially refrigerators, electric water heaters, Vacuum insulation panels for applications such as cold storage. Background technique [0002] Due to its good heat insulation effect, vacuum insulation panels have gradually been widely used in thermal insulation fields such as petroleum, chemical industry, construction, refrigerators, and heat preservation cookers. The thermal insulation performance of the vacuum insulation panel mainly depends on the internal vacuum degree and the thermal conductivity of the core material. [0003] The vacuum degree in the vacuum insulation panel is related to the air penetration of the external sealing material, the outgassing of the core support material, and the residual gas during sealing. According to different combinations, the gette...

AI Technical Summary

Problems solved by technology

Although these methods can absorb nitrogen, there is one biggest defect. The metal barium will form hydrogen with the water vapor in the heat shield, and the thermal conductivity of hydrogen is 8 times that of nitrogen, which not only does not reduce the thermal conductivity of the vacuum heat shield. However, the thermal conductivity of the vacuum insulation panel is improved. Even if there is not much moisture in the vacuum insulation panel at the beginning, the metal barium reacts with nitrogen and oxygen to form barium nitride and barium oxide, but with the gradual penetration and release of water vapor , barium nitride will react with water vapor to generate ammonia, and its effect on reducing the thermal conductivity of vacuum insulation panels is not obvious

[0009] And these methods also have safety issues. Since the EU WEEE directive came into effect, when using vacuum insulation panels for electrical recycling operations, electrical appliances need to be broken, and water mist needs to be sprayed for dust reduction.

Even if the excess metal barium produced by the above-mentioned method of using evaporable barium getter is exposed to the atmosphere, it is difficult to completely react with the air at once, so that the reaction of metal barium and water will release dangerous hydrogen gas

Although the method of using barium-lithium alloy announced by Chinese patent 92121883 can eliminate the influence of water vapor, the reaction speed of the barium-lithium alloy powder it uses in the air is slower on the one hand, and because its specific surface area is smaller on the other hand, it needs Excessive barium-lithium alloys are used, so the safety hazards in recycling operations are even greater