Alternative Selections of Delayed Coke Drum Materials Based on ASME Material Property Data

2012 ◽  
Author(s):  
Milan Nikic ◽  
Zihui Xia
Keyword(s):  
Finite Element ◽  
Material Property ◽  
Base Material ◽  
Operating Conditions ◽  
Finite Element Analyses ◽  
Damage And Failure ◽  
Property Data ◽  
Operation Cycle ◽  
Heating Up ◽  
Material Property Data

Severe cyclic thermo-mechanical operating conditions during delayed coking can cause damages in the form of bulging and cracking in coke drums. As a result, the industry has to perform costly repairs and maintenance shutdowns. Therefore, it is important to understand the damage and failure mechanisms of the coke drums and to achieve more reliable coke drum design solutions. This paper explores alternative selections of clad and base material combinations for coke drum applications based on material property data provided in ASME Boiler & Pressure Vessel Code, Section II - Materials. Finite element analyses are carried out by simulating two critical loading scenarios in the coke drum operation cycle, i.e. the heating up and quenching stages. The analysis results show that the major achievement in lowering the stress level in the clad layer is due to matching of the coefficients of thermal expansion between clad and base materials. In addition, the finite element analyses indicate that the differences in Young’s modulus values play an important role in the variation of maximum stress in the coke drum shell during the quenching stage. Among eleven pairs of the clad and base material combinations studied, the combination of SA302-C as the base and nickel alloy N06625 as the cladding material is recommended.

Assessment of Coke Drum Materials Based on ASME Material Property Data

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Milan Nikic ◽  
Zihui Xia ◽  
Pierre Du Plessis
Keyword(s):  
Material Property ◽  
Material Selection ◽  
Base Material ◽  
Operating Conditions ◽  
Base Materials ◽  
Property Data ◽  
Alternative Material ◽  
Operation Cycle ◽  
Heating Up ◽  
Material Property Data

Delayed coking as a part of heavy oil upgrading is characterized with severe thermal–mechanical operating conditions. Coke drums operating under such conditions require proper design and material selection in order to sustain the high stresses caused by the thermal–mechanical loading. This paper has the objective to explore alternative material selections for coke drum applications based on material property data provided in ASME Boiler & Pressure Vessel Code, Section II—Materials. The materials were compared based on the stress levels obtained by using finite element analyses (FEA) for two critical loading scenarios in the coke drum operation cycle, i.e., the heating up and quenching stages. The results show that closer matching in the coefficients of thermal expansion (CTE) between clad and base materials reduce significantly the stress in the clad during heating up stage. Among other material properties, the results show that the variation in Young's modulus values of base materials plays an important role in the variation of maximum stress in the coke drum shell during the bending of the shell caused by quenching water. Among the considered 11 pairs of clad and base material combinations, the combination of SA302-C as the base material and nickel alloy N06625 as the cladding material is recommended for delayed coke drum application.

The European Union Mg-Engine Project - Generation of Material Property Data for Four Die Cast Mg-Alloys

2006 ◽  
Author(s):  
Per Bakke ◽  
Andreas Fischersworring-Bunk ◽  
Isabelle de Lima ◽  
Hans Lilholt ◽  
Ingemar Bertilsson ◽  
...  
Keyword(s):  
European Union ◽  
Material Property ◽  
Mg Alloys ◽  
The European Union ◽  
Property Data ◽  
Die Cast ◽  
Material Property Data

Requirements for Numerical Flange Calculations According to the German Nuclear Code

2002 ◽  
Author(s):  
Robert Kauer
Keyword(s):  
Finite Element ◽  
Operating Conditions ◽  
Metal Contact ◽  
Finite Element Analyses ◽  
Rate Dependency ◽  
New Approach ◽  
Contact Type ◽  
Numerical Finite Element ◽  
Floating Type ◽  
Code Compliance

In Europe as well as in other countries a lot of effort is invested into developing new codes and standards for bolted joints under various loading conditions. The standardization of gasket factors and the improvement of calculation methods with respect to these factors characterize the last couple of years in this area. In Germany the nuclear code (KTA) is also influenced by this development. So, the leak rate dependency of gasket factors and the results of a research program on metal-to-metal contact type flanges were introduced into the new approach of the code for Class 2 and 3 components. Herein flange calculations can be performed for various flange types, floating type and metal-to-metal contact type. Generally, the calculations to be performed can be separated into a design step and the proof of sufficient tightness and strength of flange, bolts and gasket for the various operating conditions according to the chosen bolting method. In this step the stiffness of all components (flanges, bolts and gasket) and its influence on the mechanical behavior of the entire system is considered. Besides, influences caused by thermal effects, e.g. different thermal expansion between the flanges and the bolts, or seating effects in the gasket must be regarded. In cases, where the allowable stress values are not satisfied by performing code calculations or in cases, where the applicability of the code is not given, e.g. due to geometric facts, Finite-Element analyses often replace code calculations to show code compliance. Therefore, numerical Finite-Element analyses, performed according to a special code, e.g. KTA, must also fulfill the requirements of the code with respect to considered load cases, bolting condition, allowable stresses etc., to get an adequate testimony for a certain flange joint. In this paper certain methods for numerical calculations will be presented and compared to the results of the code for various flange types and dimensions.

Tank Car Puncture Analyses for Various Impactors and Impact Conditions

2013 ◽  
Author(s):  
Steven W. Kirkpatrick ◽  
Francisco Gonzalez ◽  
Karl Alexy
Keyword(s):  
Finite Element ◽  
Research Program ◽  
Impact Testing ◽  
Impact Behavior ◽  
Finite Element Analyses ◽  
Damage And Failure ◽  
Wide Range ◽  
Significant Research ◽  
Detailed Simulation ◽  
The Impact

There has been significant research in recent years to analyze and improve the impact behavior and puncture resistance of railroad tank cars. Much of this research has been performed using detailed nonlinear finite element analyses supported by full scale impact testing. This use of detailed simulation methodologies has significantly improved our understanding of the tank impact behaviors and puncture prediction. However, the evaluations in these past studies were primarily performed for a few idealized impact scenarios. This paper describes a research program to evaluate railroad tank car puncture behaviors under more general impact conditions. The approach used in this research program was to apply a tank impact and puncture prediction capability using detailed finite element analyses (FEA). The analysis methodologies apply advanced damage and failure models that were validated by series of material tests under various loading conditions. In this study, the analyses were applied to investigate the tank puncture behaviors for a wide range of impact conditions.

Sign in / Sign up

Export Citation Format

Share Document