Study on Design Approach for Tall Pressure Vessels With Intermediate Support in Consideration of Bottom Structure Flexibility

2021 ◽  
Author(s):  
Shunsuke Sasaki ◽  
Takanori Nanjo ◽  
Toshikazu Miyashita ◽  
Shunji Kataoka ◽  
Yoshiaki Uno
Keyword(s):  
Pressure Vessels ◽  
Design Approach ◽  
Intermediate Support ◽  
Structure Flexibility

Study on Design Approach for Tall Pressure Vessels With Intermediate Support in Consideration of Bottom Structure Flexibility

2020 ◽  
Author(s):  
Shunsuke Sasaki ◽  
Takanori Nanjo ◽  
Toshikazu Miyashita ◽  
Shunji Kataoka ◽  
Yoshiaki Uno
Keyword(s):  
Pressure Vessel ◽  
Reaction Force ◽  
Steel Structure ◽  
Pressure Vessels ◽  
Design Approach ◽  
Intermediate Support ◽  
Fixed Model ◽  
Structure Flexibility ◽  
Additional Support ◽  
The Impact

Abstract The skirt and shell thicknesses of vertical tall pressure vessels are sometimes much increased in FPSO (Floating Production, Storage and Offloading) due to ship motion acceleration. In that case, intermediate support is used as an additional support from steel structure surrounding the vessels. By theoretical calculation, Nanjo et.al. introduced dimensionless parameter N that can represent stiffness of pressure vessel and acceleration load with the assumption of structure drift at intermediate support [1]. The authors proposed N-chart to investigate the necessity and effective elevation of intermediate support by using the parameter N. The flexibility of steel structure on the bottom affects the function of intermediate support (e.g. increasing reaction force at intermediate support, effect on bottom skirt calculation); however, the flexibility is not included in the parameter N. In this paper, an additional factor for the flexibility was studied and introduced by structural analysis. A model with flexibility of structure supporting the bottom skirt was used for the analysis. The variable flexibility of steel structure was applied to the bottom of the model to study the impact of bottom structure flexibility on the pressure vessel design. The analysis result was compared with the bottom fixed model without structure flexibility to study an additional factor. Finally, appropriate design approach for tall pressure vessels with intermediate supports was proposed.

scholarly journals Pressure Cycling of Steel Pressure Vessels With Gaseous Hydrogen

2012 ◽  
Author(s):  
C. San Marchi ◽  
A. Harris ◽  
M. Yip ◽  
B. P. Somerday ◽  
K. A. Nibur
Keyword(s):  
Wall Thickness ◽  
Large Scale ◽  
Pressure Vessels ◽  
Gaseous Hydrogen ◽  
Design Approach ◽  
Manufacturing Defects ◽  
Pressure Cycling ◽  
Fuel Tanks ◽  
Fuel Storage ◽  
Number Of Cycles

Steel pressure vessels are commonly used for the transport of pressurized gases, including gaseous hydrogen. In the majority of cases, these transport cylinders experience relatively few pressure cycles over their lifetime, perhaps as many as 25 per year, and generally significantly less. For fueling applications, as in fuel tanks on hydrogen-powered industrial trucks, the hydrogen fuel systems may experience thousands of cycles over their lifetime. Similarly, it can be anticipated that the use of tube trailers for large-scale distribution of gaseous hydrogen will require lifetimes of thousands of pressure cycles. This study investigates the fatigue life of steel pressure vessels that are similar to transport cylinders by subjecting full-scale vessels to pressure cycles with gaseous hydrogen between nominal pressure of 3 and 44 MPa. In addition to pressure cycling of vessels that are similar to those in service, engineered defects were machined on the inside of several pressure vessels to simulate manufacturing defects and to initiate failure after relatively low number of cycles. Failure was not observed in as-manufactured vessels with more than 55,000 pressure cycles, nor in vessels with relatively small, engineered defects subjected to more than 40,000 cycles. Large engineered defects (with depth greater than 5% of the wall thickness) resulted in failure after 8,000 to 15,000 pressure cycles. Defects machined to depths less than 5% wall thickness did not induce failures. Four pressure vessel failures were observed during the course of this project and, in all cases, failure occurred by leak before burst. The performance of the tested vessels is compared to two design approaches: fracture mechanics design approach and traditional fatigue analysis design approach. The results from this work have been used as the basis for the design rules for Type 1 fuel tanks in the standard entitled “Compressed Hydrogen-Powered Industrial Truck, On-board Fuel Storage and Handling Components (HPIT1)” from CSA America.

1250-kilovolt scanning transmission electron microscope

1984 ◽  
Vol 42 ◽  
pp. 624-625
Author(s):  
T. Imura ◽  
S. Maruse ◽  
K. Mihama ◽  
M. Iseki ◽  
M. Hibino ◽  
...  
Keyword(s):  
High Voltage ◽  
Electron Probe ◽  
Scanning Transmission Electron Microscope ◽  
Pressure Vessels ◽  
Practical Applications ◽  
Voltage Generator ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
New Applications ◽  
High Voltage Generator

Ultra high voltage STEM has many inherent technical advantages over CTEM. These advantages include better signal detectability and signal processing capability. It is hoped that it will explore some new applications which were previously not possible. Conventional STEM (including CTEM with STEM attachment), however, has been unable to provide these inherent advantages due to insufficient performance and engineering problems. Recently we have developed a new 1250 kV STEM and completed installation at Nagoya University in Japan. It has been designed to break through conventional engineering limitations and bring about theoretical advantage in practical applications.In the design of this instrument, we exercised maximum care in providing a stable electron probe. A high voltage generator and an accelerator are housed in two separate pressure vessels and they are connected with a high voltage resistor cable.(Fig. 1) This design minimized induction generated from the high voltage generator, which is a high frequency Cockcroft-Walton type, being transmitted to the electron probe.

Probabilistic evaluation of detection capability of eddy current testing to inspect pitting on a stainless steel clad using multiple signal features

2020 ◽  
Vol 64 (1-4) ◽  
pp. 47-55
Author(s):  
Takuma Tomizawa ◽  
Haicheng Song ◽  
Noritaka Yusa
Keyword(s):  
Stainless Steel ◽  
Eddy Current ◽  
Pressure Vessels ◽  
Eddy Current Testing ◽  
Probability Of Detection ◽  
Current Testing ◽  
Multiple Signal ◽  
Signal Features ◽  
Inner Surface ◽  
Drill Holes

This study proposes a probability of detection (POD) model to quantitatively evaluate the capability of eddy current testing to detect flaws on the inner surface of pressure vessels cladded by stainless steel and in the presence of high noise level. Welded plate samples with drill holes were prepared to simulate corrosion that typically appears on the inner surface of large-scale pressure vessels. The signals generated by the drill holes and the noise caused by the weld were examined using eddy current testing. A hit/miss-based POD model with multiple flaw parameters and multiple signal features was proposed to analyze the measured signals. It is shown that the proposed model is able to more reasonably characterize the detectability of eddy current signals compared to conventional models that consider a single signal feature.

Towards a Tangible Philosophy through Design

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Jelle VAN DIJK ◽  
Jonne VAN BELLE ◽  
Wouter EGGINK
Keyword(s):  
Digital Age ◽  
Promising Method ◽  
Design Approach ◽  
The World ◽  
First Results

The combined philosophy and design approach called Philosophy-through-Design (PtD) is proposed using an exemplary project about being-in-the-world in the digital age. PtD is a practical way to do philosophy through designing interventions, and involves various people in the exploration of philosophical concepts. It stems from the overlapping questions found in philosophy and design regarding human-technology interaction. By intertwining both, they benefit from describing, understanding and proposing human-technology interactions to unfold new questions and perspectives. In the exemplary project, being-in-the-world refers to a way of being that is embodied, active, open-ended and situational, based on the phenomenological and embodied theories of Tim Ingold. This concept questions what it means to be human in the digital age and how our lives with technology are built. The first results show the process of weaving together observation, creation and reflection, which presents Philosophy-through-Design as a promising method for designers to practice a tangible philosophy.

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