Perlite expansion ＆ filling technique for LNG storage tanks and relevant quality control

        As a key procedure of LNG storage tank construction at late stages, perlite expansion filling may directly determine insulation 

performances of such tanks after they are put into service. Major perlite expansion and fi lling facilities on site include silos for raw 

materials, expansion oven, cyclone separator, heat exchanger, dust catcher, conveyer system and vibrator. Main procedures for 

filling of expanded perlite include preparation, fi lling, monitoring of effects and vibrating after filling. Since the perlite expansion and filling for LNG storage tanks are operations around the clock, densimeters and particle size analyzers should be mobilized to 

monitor loose density, compacted density, granularity grading, moisture content and thermal conductivity of perlite throughout the 

operations. All relevant data obtained in such procedures should be recorded properly. These data may serve as the basis for 

adjusting the expansion process of perlite. In this way, BOG evaporation of the LNG storage tanks can be ensured to eliminate 

possibility of poor performance or failure in insulation of perlite in storage tank.