STS U 밴드 적용 연도의 기밀성 실험 및 누기량 예측

Chimney is a device that discharges harmful exhaust gases produced during combustion of fossil fuel into the atmosphere. In this study, binding force analysis and air-tightness test of existing V-band and STS spring U-band were performed. U-band uses a STS spring to exert binding force at the connection of chimney pipe parts. The binding force of V-band type is zero since it relies only on sealant which ultimately gets hardened, resulting in cracks after a long-time use. As a result of the pressure drop test for 40 minutes, the pressure of V-band descended largely, while the U-band showed relatively little pressure drop. Pressure drop was about 79% lower than that of the V-band. As a result of the calculation of the leakage amount and the leakage rate, the V-band leaked mass was 2.23 g and the leakage rate was 23.3%, while the U-band leaked mass was 0.33 g and the leakage rate was 3.5%. Leakage rates of V-band and U-band were measured to be 0.000232 and 0.000034 liter/s⋅㎡, respectively. Leakage of U-band was 85% lower than that of V-band. Both types satisfied the criteria of 0.12 liter/s⋅㎡ of SPS-KARSE B 0042-204 Test code for pre-fabricated chimney for exhausting combustion gas. This study shows that U-band is better than conventional V-band for connecting chimney parts in terms of binding force and air-tightness.