Causes of thermal stress damage of enamel reactor
Enamel reaction tank is usually used in petrochemical, rubber, pesticide, dye, pharmaceutical and other industries, complete organic dyes and intermediates of sulfonation, nitration, hydrogenation, alkylation, polymerization, condensation and other processes and equipment. Low pressure reactor generally refers to 1.6 MPA below the reactor. The enamel glass is baked at 900 °C and bonded to steel plate after cooling. Let’s take a quick look.
1. Because the linear expansion coefficient and elongation of the enamel in the enamel reactor are smaller than that of the steel plate, and the deformation of the enamel after cooling is smaller than that of the steel plate, the enamel is restrained by the steel plate to produce compressive stress. In order to reduce the cost, the use of non-conforming steel, which directly leads to steel carbon and sulfur in the enamel process gasification, in the enamel layer and the matrix between the formation of a large number of bubbles, lead to the formation of enamel layer and reduce the bond strength. The enamel layer changes rapidly in hot and cold conditions and is very explosive. Therefore, the enamel pot made of low carbon steel and low sulfur steel to prevent porcelain explosion.
2. After the manufacture of the enamel reactor, the enamel has pre-stress and the steel plate has pre-stress. Because the prestress is related to the linear expansion coefficient and the elongation, and the linear expansion coefficient and the elongation are closely related to the temperature, so the working temperature has a great influence on the use of enamel reactor.
During the processing of enamel reactor, a lot of internal stress is produced because of drum, stamping and welding. These stresses should be completely eliminated before glazing. If it can not be completely eliminated, porcelain explosion will occur. This injury usually occurs in the first three months after use. Therefore, heat treatment or aging of embryos can prevent porcelain explosion.
