Session: DA-01-01 The Roger F. Reedy Memorial Symposium on Design & Analysis of Pressure Vessels and Components - 1

Paper Number: 105665

105665 - Design Considerations for Pressure Vessels Containing a Top Mounted Agitator 

Pressure vessels containing agitators supported by a nozzle on the vessel top cover are commonly used in a variety of industrial applications such as electric car battery material plants, metal refining plants, plastic recycling plants, food processing facilities, petrochemical plants and in the pharmaceutical industry.

The loads and moments induced by the agitator on both the top cover and the supporting nozzle are often cyclic in nature and it is common that these be ignored or only partially evaluated during the design of the vessel, when there may be time constraints or lack of resources. This can result in a shorter operating life for the agitator or its drive mechanism than originally expected and it may result in vibrational issues that lead to fatigue failures in the top cover or the nozzle.

A correctly designed top cover and nozzle support for an agitator should be strong enough to withstand the sustained cyclic loads and contain features so it is acceptable for the cyclic conditions to allow the safe use of the equipment for the entirety of its intended design life.

The purpose of this paper is to firstly explain some of the recommended features that should be taken into account during the design and fabrication of agitator-mounted vessels and then to investigate a simple approach to estimate the fatigue damage on the nozzle. The suggested method will then be further examined against FEA results to ascertain its validity. ASME Sec. VIII Div.2 and/or British PD 5500 fatigue design rules will be considered for the evaluation.

Presenting Author: Barry Millet Fluor

Presenting Author Biography: Barry Millet is Senior Fellow of Pressure Vessels in Fluor Houston, Texas.

Mr. Millet’s background covers design, analysis, fabrication, procurement and revamping of pressure vessels and pressure vessel systems. His pressure vessel experience covers nuclear reactors, hydrocracker and hydrotreater reactors, FCC units, CCR units, gasification reactors, coke drums, and vacuum columns.

Mr. Millet’s work experience began at Babcock and Wilcox as a manufacturing engineering in the Nuclear Equipment division. He moved on to Liquid Carbonic (CB&I) where he designed cryogenic freezing systems and developed methods analysing spiral conveying systems. Following this role, he worked for Dyna-Therm where he designed Section I pressure vessels, performed structural analysis, and developed software for performing code calculation.
With over 35 years of experience , Mr. Millet has held many positions in Fluor. He has been a pressure vessel engineer, head of the pressure vessel group, lead mechanical engineer, member of the mechanical analysis support team, head of the complex vessel group, and technical lead for the pressure vessel group. He has written software for design and analysis of pressure vessels and structures. He is knowledgeable of and competent in finite element analysis and computational fluid dynamics (CFD). Mr. Millet has done several technical presentations and co-authored several technical papers on topics ranging from coke drums to CFD.

Mr Millet has been a member of PIP for Pressure Vessels, is an active member of API 934 A, B & G and a member of American Society of Mechanical Engineers Boiler and Pressure Vessel committee.

Authors:

Kaveh Ebrahimi Fluor Limited
Barry Millet Fluor
Kenneth Kirkpatrick Fluor
Jessica Depner Fluor Limited