Factors Affecting the Repair Quality of Enamel Reactor
2021-11-12
The enamel reactor is mostly used in the chemical industry. Due to the corrosiveness of the medium and the hot and cold reaction conditions, the inner layer of the enamel is easily damaged. The cost of the reactor is high, and minor damage can be repaired, but the factors that affect the quality of the reactor repair What are there?
1. Selection and dosage of epoxy resin
There are many kinds of epoxy resins, and the difference in their molecular weights is also large, and the molecular weight has a great influence on the reaction process with silicone resin and the performance of polycondensation products. Because the greater the molecular mass of the epoxy resin, the more difficult it is to stop the polycondensation reaction; the smaller the molecular mass of the epoxy resin, the smaller the improvement in the heat resistance of the polycondensation product, and it is easily destroyed after being heated. Accordingly, we selected bisphenol E-20 epoxy resin with moderate molecular weight as the modified resin base material.
The smaller the proportion of epoxy resin E-20 in the polycondensate, the better the temperature resistance of the repair layer, but the worse the bonding strength of the repair layer. When the mass ratio of epoxy resin E-20 to silicone resin is 40:60, the room temperature shear strength of the repair layer is 15.4MPa; when the ratio is 50:50, the room temperature shear strength of the repair layer reaches 20.5MPa. In order to make the repair layer have both good temperature resistance and good bonding strength, the ratio we choose is 50:50.
2. The influence of toughening agent
The main disadvantages of epoxy resin binders are that the glue line is brittle and has poor impact and peel strength. The introduction of high molecular weight elastomers into the epoxy resin curing system has a good effect on improving the toughness of the adhesive.
Whether the choice of toughening agent is appropriate or not directly affects the bonding strength of the adhesive. For modified epoxy resin adhesives, polyvinyl butyral is selected as the toughening agent because of its high molecular weight, which can improve the cohesive strength of the adhesive layer, increase the toughness of the adhesive layer, and help improve the toughness of the adhesive layer. impact strength and peel strength; at the same time, because of the hydroxyl group in its molecular structure, it can further undergo polycondensation reaction with the hydroxyl group in the condensation polymer of silicone resin and epoxy resin to form a planar network molecular structure, which can not only improve the toughness of the adhesive layer In addition, it can also improve the temperature resistance of the adhesive layer.
3. The influence of quenching temperature
Generally, the cold shock resistance temperature of the acid-resistant reactor is ≤110°C. If a liquid lower than 110°C is sprayed on the repair layer at 180°C, porcelain explosion may occur. Therefore, we adopt the method of increasing the temperature of the quenching liquid while reducing the temperature of the repair layer, so that the acceptable cold shock temperature of the enamel surface of the reactor is lower than 110°C.
The above is the introduction of the factors that affect the repair quality of the enamel reactor. According to the introduction, the equipment can be used better, the occurrence of failures and other situations can be reduced, and its service life can be effectively extended.