Preparation Of Heat Resistant Coating And Study Of Heat-insulation Mechanism

With the national economy developed rapidly,the environment pollution and energy shortage have been accumulating prominent.Facing to the imminent energy crisis,the government hadgradually introduced several energy-saving policies,and Saving energy became a research focus.The thermal insulation coating is a kind of function material for preventing heat from transfer.The thermal insulation coating can prevent heat from lossingfor high temperature pipeline,and it can reduce the energy consumption of air conditioning for building materials.the sources of material is widely.This new material has the advantages of environmental protection and energy saving.Perlite,floating beads,vitrified microsphere,glass bead was used in the research,they are all light qualityparticles.they select water glass,silica sol,polymer binder as the coating's adhesive,aluminum silicate fibers were used as enhancements.According to the different of adhesive,we prepared three kinds of thermal insulation coating,respectively,water glass insulation coating,silica sol insulation coating,glass beads composite insulation coating.The effects of particle size and aggregate on the properties of coatings were studied,the effects of fiber,defoamer and dispersant on the properties of coatings were analyzed.The thermal insulation properties and thermal conductivity of the coatings were tested,The thermal conductivity of the coating on the surface of the tube was calculated,The thermal insulation mechanism of coating was studied,the microstructure of the coating was also analyzed,Research indicates:Water glass-based thermal insulation coating,the drift beads was used as aggregate,when the grading proportionis15mesh: 20mesh: 24 mesh =1:5:5,the thermal conductivity of the coating is 0.28 W/(m k),dry bulk density is 800kg/m3,When the experimental temperature is 350?,the surface temperature of the 6cm thick coating was 80°C,insulation temperature is 270?.Thermal insulation coating of silica sol,perlite is was used as aggregate,glass bead fillers are used to block radiative heat transfer,when the solid and liquid ratio is 4:6,the thermal conductivity of the coating is 0.16 W/(m·k),the dry bulk density is 500 kg/m3,when the experimental temperature is 350?,the surface temperature of the 6cm thick coating was 47°C,the insulation temperature is 303?.The 48 hour water absorption was 8.6%.Glass beads composite insulation coating,glass beads was used as aggregate,the particle size of the vitrified microbeads is 50-100 mesh,12% fiber was added,the thermal conductivity of the coating is 0.08 W/(m·k),the dry bulk density is 300 kg/m3,the insulation temperature is 303?.The comparison of three kind of coating's performance: The thermal insulation performance of the composite coating is the best,but the water resistance is poor.Thermal insulation properties of silica sol based coatingsisn't good,but the waterproof performance is good.The water glass-based insulation coating's thermal insulation and water resistanceisn't good.The thermal conductivity and thermal conductivity of the coatings were calculated,the thermal conductivity of the coating is the sum of the thermal conductivity of the film-forming base and the filler,The heat transfer rate of the coating is directly proportional to the heat transfer coefficient of the solid phase in the coating,the microstructure of the coating determines the thermal insulation properties of the coating.The coating is a compact filled structure formed by hollow spheres of particles of different sizes,The "vacuum wall" was formedby numerous vacuum cavity,While the presence of fiber,So that the coating to form three-dimensional network structure,So as to effectively ensure that the coating has excellent thermal insulation properties.