Addition of Molten Salt in Molten Metal. Structure
                                                and Dynamics

Understanding the freezing behavior of molten metal in flow channels is of importance for severe accident analysis of liquid metal reactors. In order to simulate its fundamental behavior, a 3D fluid dynamics code was developed using Finite Volume Particle (FVP) method, which is one of the moving particle methods. This method, which is fully Lagrangian particle method, assumes that each moving particle occupies certain volume. The governing equations that determine the phase change process are solved by discretizing its gradient and Laplacian terms with the moving particles. The motions of each particle and heat transfer between particles are calculated through interaction with its neighboring particles. A series of experiments for fundamental freezing behavior of molten metal during penetration on to a metal structure was also performed to provide data for the validation of the developed code. The comparison between simulation and experimental results indicates that the present 3D code using the FVP method can successfully reproduce the observed freezing process such as molten metal temperature profile, frozen molten metal shape and its penetration length on the metal structure.

Download Full-text

A multi-purpose pilot-scale molten metal & molten salt pyrolysis reactor

MethodsX ◽

10.1016/j.mex.2021.101606 ◽

2021 ◽

pp. 101606

Author(s):

Frank Riedewald ◽

Ian Povey ◽

Maria O'Mahoney ◽

Maria Sousa-Gallagher

Keyword(s):

Molten Salt ◽

Molten Metal ◽

Pilot Scale ◽

Pyrolysis Reactor

Download Full-text

A Novel Technique to Produce Metal Slurries for Semi-Solid Metal Processing

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.116-117.366 ◽

2006 ◽

Vol 116-117 ◽

pp. 366-369 ◽

Cited By ~ 31

Author(s):

J. Wannasin ◽

R. Andy Martinez ◽

M.C. Flemings

Keyword(s):

Molten Metal ◽

Systematic Study ◽

Necessary Conditions ◽

Metal Structure ◽

Solid Metal ◽

Metal Structures ◽

Novel Technique ◽

Metal Processing ◽

A New Technique ◽

Semi Solid

Various processing methods exist for applying agitation to a molten metal during solidification to obtain metal slurries suitable for semi-solid metal processing. . In this paper, a new technique to achieve semi-solid metal structure using agitation during solidification is reported. The technique applies a new medium and means to efficiently create semi-solid metal structures. The results of a systematic study showing the feasibility and the necessary conditions to achieve the structure are discussed.

Download Full-text

Challenges Experienced in Scaling-Up the CSIR-Ti Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1019.187 ◽

2014 ◽

Vol 1019 ◽

pp. 187-194 ◽

Cited By ~ 1

Author(s):

Salomon Johannes Oosthuizen ◽

Jaco Johannes Swanepoel ◽

Dawid Steyn van Vuuren

Keyword(s):

High Temperature ◽

Molten Salt ◽

Metal Powder ◽

Molten Metal ◽

Pilot Plant ◽

Scaling Up ◽

Small Scale ◽

Titanium Metal ◽

Feed System ◽

Compact Size

The CSIR-Ti process produces titanium metal powder through continuous stepwise metallothermic reduction of titanium tetrachloride (TiCl4) in molten salt medium, and represents a cost-effective alternative to the standard Kroll process to produce titanium metal. Subsequent to proving the CSIR-Ti process at bench scale producing batches of ±2 kg titanium powder, the design, build and test of a continuous 2 kg/h Ti pilot plant was authorised. The scale-up process highlighted limited expertise in South Africa with regards to handling molten salt and molten reducing metals. Such gaps in knowledge are addressed in this study, which discusses a number of the engineering challenges faced and solutions developed around agitation of molten salt reactors, process pipe heating and insulation, molten salt flow measurement and also feeding of a highly reactive molten reducing metal. Scaling up the CSIR-Ti process, with requirements of continuous operation, compact size, effective agitation, pumping and maintaining salt in the molten state brought an unusual set of challenges requiring development of unique and prototype equipment. Further challenges were encountered in the handling and continuous feeding of molten reducing metal at the relatively small scale of the pilot plant. Solutions developed and discussed in this study include custom-modified agitators, custom-developed flow meters for measuring molten salt and molten metal flows, and a custom-designed molten metal feed system. Specialised materials such as, ultra-high temperature heating tape and ultra-low thermal conductivity insulation had to be imported as well as a special high-temperature pump that can pump a slurry consisting of molten salt containing a high weight percentage of suspended metal powder. The experience illustrates the technological difficulty of bridging the chasm between science and technology in that many unforeseen problems are encountered when developing and scaling up a new technology.

Download Full-text

Quick Semi-Solid Slurry Making Method Using Metallic Cup

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.141-143.463 ◽

2008 ◽

Vol 141-143 ◽

pp. 463-468 ◽

Cited By ~ 3

Author(s):

Farshid Pahlevani ◽

Koichi Anzai ◽

E. Niyama

Keyword(s):

Molten Metal ◽

High Strength ◽

Metal Structure ◽

Solid Metal ◽

Processing Route ◽

Aerospace Structure ◽

A New Technique ◽

Semi Solid ◽

Spherical Growth

The needs for high-strength and light weight structural materials have increased in automotive and aerospace structure applications. The semi-solid processed light alloys inherently offer the opportunity to produce high integrity components for these requirements. Various processing methods exist for applying agitation to a molten metal during solidification to obtain metal slurries suitable for semi-solid metal processing. In this paper, a new technique (Cup-Cast method) to achieve semi-solid metal structure using agitation and direct spherical growth during solidification is reported. Cup-Cast method is the most quick and simple semi-solid processing route which semi-solid slurry would be prepared just by pouring molten metal into a metallic cup. In this study Cup-Cast method was introduced and effect of process parameters on micro-structural characterization of slurry prepared by this method was investigated.

Download Full-text

Nucleosome dynamics

Biochemical Society Symposium ◽

10.1042/bss0730109 ◽

2006 ◽

Vol 73 ◽

pp. 109-119 ◽

Cited By ~ 2

Author(s):

Chris Stockdale ◽

Michael Bruno ◽

Helder Ferreira ◽

Elisa Garcia-Wilson ◽

Nicola Wiechens ◽

...

Keyword(s):

High Resolution ◽

Chromatin Structure ◽

Current Knowledge ◽

Dynamic Properties ◽

Structure And Dynamics ◽

Nucleosome Dynamics ◽

Sharp Focus ◽

Recent Advances ◽

Insight Into ◽

Chromatin Structure And Dynamics

In the 30 years since the discovery of the nucleosome, our picture of it has come into sharp focus. The recent high-resolution structures have provided a wealth of insight into the function of the nucleosome, but they are inherently static. Our current knowledge of how nucleosomes can be reconfigured dynamically is at a much earlier stage. Here, recent advances in the understanding of chromatin structure and dynamics are highlighted. The ways in which different modes of nucleosome reconfiguration are likely to influence each other are discussed, and some of the factors likely to regulate the dynamic properties of nucleosomes are considered.

Download Full-text