Aiming at the problem of instability in the 8 shaped shell with nozzle structure of biaxial self cleaning reactor under excessive external pressure, the finite element analysis method was used to investigate the external pressure stability of 8 shaped shell with nozzle structure of the biaxial self cleaning reactor. When the distance between the nozzle centerline and the vertical centerline of the 8 shaped shell X was 0.0a,0.4a and 0.5a,Do/δe was 30, 40, 50, 60 and 70, L/Do was 2, 3, 4, 5and 6, d/D was 0.10,0.25,0.40,0.55 and 0.70, δet/δewas 0.2,0.6,1.0,1.4 and 1.8, the relationship between various structural parameters and the critical destabilizing pressure weakening coefficient K was investigated.The results show that the external pressure bearing capacity of the 8 shaped shell of nozzle structure is significantly weakened for the smaller δet/δe, the smaller L/Do,the larger d/D, and the larger Do/δe. |