ANTICORROSION PROTECTION OF THE HEAT-EXCHANGE EQUIPMENT OF FARM PROCESSING ENTERPRISES WITH REPAIR AND RECOVERY COATINGS

Analysis of repair methods of shell-and-tube heat exchangers (STHE) has shown the necessity to develop a new
approach to the repair and reconditioning organization of STHE heat transfer tubes. One of the promising ways to restore and protect STHE tubes is to treat them with polymer compounds especially with heat-dissipating plastics – polymers with greatly increased thermal conductivity. In the research, a method for corrosion protection and restoration of STHE surfaces is proposed. This method consists in using liquid reactive oligomers or monomers to form a coating in the treated circuit without using special in-tube devices. To initiate curing, a coolant with a temperature equal to or higher than the curing temperature of the coating material is introduced into the adjacent STHE circuit. Heat transfer process was modeled from the coolant to the material (compound) through the separating wall, which allowed to determine the requirements for the compound necessary to implement the discussed method. According to the established requirements, the authors have proposed a compound and its curing technology with recommendations on the use of latent hardeners based on Lewis acids in the temperature ranges of 80…100°C and 120…140°C. The proposed method of protecting and reconditioning STHE tubes allows to apply a uniform coating with a predefi ned elasticity, resistant to linear expansion of the tube metal and with a thickness suffi cient to seal through-wall defects.