In the manufacturing process of the glass-lined reactor, a large amount of internal stress will be generated due to bulging, stamping, welding, etc. These stresses should be relieved by heat treatment prior to glazing the base. However, some manufacturers did not eliminate or completely eliminate the stress during the heat treatment process, resulting in a large amount of residual stress in the equipment. When the glass-lined reactor is in operation, the r-angle and the weld are prone to porcelain explosion damage.
After the glass-lined reactor is perforated, if acid or acid solution is put into the jacket, or if the heat transfer medium is acidic, hydrogen gas will be generated. Some of the hydrogen atoms diffuse into the inner cavities of the metal, where they combine to form hydrogen molecules. Since hydrogen molecules cannot diffuse, they will accumulate to form a huge internal pressure, causing the surface of the steel to blister or even crack, resulting in "scale explosion". When the hydrogen atoms re-enter the metal, the lattice strain increases, thereby reducing the toughness and ductility, resulting in embrittlement of the glass-lined reactor. When there is stress, hydrogen embrittlement and even corrosion cracking can occur at the same time. Glass-lined reactors that need to be re-lined should be baked at a temperature of 100-200 ° C for a sufficient time to drive off hydrogen atoms. Otherwise, the glass-lined reactor that needs to be re-glazed may still explode.
The thickness of the porcelain layer of the glass-lined reactor is generally 0.8-2mm, and the number of enamelling should be 5-7 times. In production, many enterprises reduce the number of enamelling and increase the thickness of each glaze spray. Under the same enamel temperature and time, the enamel layer will not be burnt through and sandwiched, the corrosion resistance of the enamel layer will be reduced, the bonding between the enamel layers will not be good, and the enamel layer will easily explode. In order to make up for the defects of pinholes and porcelain explosions in the production process, many manufacturers have sprayed glaze and enamel for many times, resulting in serious deformation of the flange of the glass-lined reactor.
