Design And Analysis Of Automatic Bottom Head Machine System In Coking Tower

In the petroleum refining industry, delay coking as a residue oil process is widely used, coke drum is the key equipment in the whole set of device. Due to the specificity of delay coking process, the working environment of the bottom machine which is in the bottom of the coke drum is very complex, and it takes the recycle heat load and pressure load. So to improve the strength of bottom cap and sealing property are primary tasks. So as to ensure safety in production and decreases the workers workload and improve work efficiency.A new type of coking drum automatic bottom cap machine is put forward in the paper.it uses the technology of hydraulic to control opening cap vertically. The system provides sealing force for sealing device by the use of pre-tightening device. The opening and shutting of bottom cap is operated separately. In the paper the design structure of the system is conducted and the sealing force value is calculated.As the structure type and dimension parameter of bottom cap, and the load is very complex. So it is very hard to get the solution just by theoretical calculation. But the accurate solution can be got by finite element method. Firstly, steady temperature field analysis and heat structural coupling field is conducted, and the paths of dangerous section are defined, and then linearization results of stress intensity can be compared with the theoretical calculation results. Secondly, the sealing property of octagon gasket is assessed by both the traditional design method and PVRC method. Thirdly, the assessment of fatigue of the structure is conducted and the solution meets the requirements of fatigue. Above all, structural integrity and fatigue property meets the requirements. Lastly, analysis of cylindrical shell wall thickness of coke drum is conducted by enumeration method and numerical simulation method. The factors affecting the opening of coke drum are determined.In conclusion, the structural strength and sealing property of the coke drum bottom is enough, and it owns good future industrialization applications.