Thermal insulation storage tanks are divided into vacuum powder insulation type and atmospheric powder insulation type. Powder insulation uses low thermal conductivity powder, fiber or foam material to reduce heat input. There are two forms: one is to apply ordinary powder insulation under atmospheric pressure (stacked insulation), the insulation layer is thicker, and it is filled with dry nitrogen to maintain a positive pressure to prevent moisture from entering and condensing, and the lowest possible time is suitable for liquid nitrogen above the temperature ; Another kind of vacuum powder insulation, that is, vacuuming the space filled with powder, which reduces the heat transfer of the gas, and at the same time the powder particles also weaken the radiation heat transfer, so that the heat insulation effect is better.
The vacuum powder storage tank has a double-layer cylindrical structure, the inner cylinder and its piping are made of austenitic stainless steel, and the outer shell is made of carbon steel. The interlayer is filled with expanded perlite (also known as pearl sand) and is equipped with a specially treated adsorbent. And pumped to a high degree of vacuum (0.5 ~ 6Pa), the capacity is less than 200m3. The working pressure is relatively high (the working pressure of the two storage tanks for argon blowing at the bottom of the ladle in the fourth workshop is 2.0 Mpa), and there is a vaporizer outside the tank, which can increase the pressure in the tank and facilitate the filling of the car, but also can directly send out the pressure gas. According to the purpose, it can be divided into two types: fixed type and transport type. The fixed type is mainly used for the storage of cryogenic liquids. It is installed at the production site, use point or supply station of the cryogenic liquid; the transport type transports the cryogenic liquid from the production site or supply station to The point of use often takes the form of land transportation and water transportation. They are called tank trucks, trailers, and tankers, respectively.
The atmospheric powder storage tank has a flat-bottom double-layer structure. The inner tank is made of stainless steel. The outer shell is made of carbon steel. The inner tank contains the medium. The interlayer between the inner tank and the outer shell forms a cold storage space. The inner shell and the outer shell are all flat-bottomed structures. The ball is missing. The inner tank and the bottom of the shell are insulated with foam glass bricks, and the interlayer is insulated with pearl sand. The shell is equipped with a rotating disc ladder, and the top of the tank is equipped with an operating platform and a safety guardrail. The capacity is more than 200m3, and the largest domestic product is 2000m3, which is far behind foreign countries. The working pressure is low, about 34KPa∽40Kpa. It can be filled by liquid pump or liquid level difference. It can also be used as oxygen peak shaving supply. When the oxygen generator is temporarily stopped or the oxygen pressure is low, it will pass through the vaporizer after being pressurized by the pump. The vaporization is sent to the pipe network.
