Assessment of the Applicability of the Abrasive Water Jet Technique for Dismantling the Reactor of Fugen: Studies for Reducing the Usage of Abrasive and for Surveying the Cutting Situation Under the Water

2008 ◽  
Author(s):  
Yasuyuki Nakamura ◽  
Yoshitugu Morishita ◽  
Shinichiro Maruyama ◽  
Shinichi Tezuka ◽  
Daisuke Ogane ◽  
...  
Keyword(s):  
Water Jet ◽  
Cutting Condition ◽  
Visual Methods ◽  
Abrasive Water Jet ◽  
Supply Rate ◽  
Cutting Method ◽  
Conservation Of Momentum ◽  
Narrow Space ◽  
Mechanical Cutting ◽  
Awj Cutting

The reactor of FUGEN NPP consists of many number of double-tube arranging a pressure tube (P/T) and a calandria tube (C/T) coaxially. In the case of dismantling both a P/T and a C/T simultaneously, it is preferable to use the mechanical cutting method because it does not apply the heat to highly activated P/T and C/T, as a result, it would be suppressed to release activated particles into surrounding environment. The method is also required to use a smaller cutting device for permitting the remote control of it in a narrow space, and to have a relatively long standoff for cutting the double-tube simultaneously. The authors chose the abrasive water jet (AWJ) cutting method as one of the mechanical cutting method for dismantling the reactor. The authors have also developed the smaller AWJ cutting device and confirmed that the device is applicable to the cutting of the double-tube. On the other hand, it is an issue to reduce an amount of abrasive because it becomes the secondary radioactive waste after the cutting work. It is also difficult to survey the cutting condition by any visual methods like a TV camera in the water becoming cloudy by both used abrasive and cut metal grit. For solving these issues, the following two studies were conducted. (1) The recycle of used abrasive was examined. And it was also confirmed to be able to predict an optimal supply rate of abrasive by considering the conservation of momentum between the water jet and the abrasive. (2) It was possible to judge whether the material could be cut or not by detecting the change in the frequency characteristics of vibration or sound caused during the cutting process.

The Study on Abrasive Water Jet for Predicting the Cutting Performance and Monitoring the Cutting Situation in the Water

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Yasuyuki Nakamura ◽  
Kazuya Sano ◽  
Yoshitugu Morishita ◽  
Shinichiro Maruyama ◽  
Shinichi Tezuka ◽  
...  
Keyword(s):  
High Pressure ◽  
Water Jet ◽  
The Other ◽  
Cutting Condition ◽  
Visual Methods ◽  
Abrasive Water Jet ◽  
Supply Rate ◽  
Cutting Head ◽  
Conservation Of Momentum ◽  
Pressure Water

The abrasive water jet (AWJ), is to shoot the abrasive mixed with high-pressure water to the material for cutting, can cut most materials, such as metals and concretes in water with long stand-off means the length from the cutting head to the material for cutting. On the other hand, AWJ is required to reduce an amount of the abrasive because it becomes the waste. It is also difficult to monitor the cutting condition by any visual methods such as a TV camera in the water becoming cloudy by both used abrasive and cut metal grit. For solving these issues, some cutting tests were conducted and (1) it was possible to predict an optimal supply rate of abrasive by considering the conservation of momentum between the water jet and the abrasive. (2) It was also possible to judge whether the material could be cut successfully or not by detecting the change in the frequency characteristics of vibration or sound caused during the cutting process.

Applicability Examination and Evaluation of Reactor Dismantlement Technology in the FUGEN: Examination of Double Tubes Cutting by Abrasive Water Jet

2006 ◽  
Author(s):  
Yasuyuki Nakamura ◽  
Kouichi Kikuchi ◽  
Yoshitugu Morishita ◽  
Tatsuo Usui ◽  
Daisuke Ogane
Keyword(s):  
Zirconium Alloy ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Cutting Method ◽  
Mechanical Cutting

As a peculiar issue of the decommissioning of FUGEN, it is necessary to establish a dismantlement method for the reactor having a 224 double-tubes structure arranged with pressure and calandria tubes concentrically. Mechanical cutting method will be desirable considering the influence on the atmospheres because the double-tubes consist of highly activated zirconium alloy and zircalloy material. Therefore, the abrasive water jet method was tested and examined as a mechanical double-tube cutting method that needs the standoff comparatively longer. We confirmed the applicability of the abrasive water jet method to the dismantlement of FUGEN’s reactor.

Miniaturization of injection abrasive water jet machining process

2006 ◽  
Vol 220 (11) ◽  
pp. 1697-1705 ◽  
Author(s):  
H Orbanic ◽  
B Jurisevic ◽  
D Kramar ◽  
M Grah ◽  
M Junkar
Keyword(s):  
Water Jet ◽  
Heat Sinks ◽  
Machining Process ◽  
Process Efficiency ◽  
Abrasive Water Jet ◽  
Element Analysis ◽  
Abrasive Particles ◽  
Cutting Head ◽  
Simulation Based ◽  
Awj Cutting

This contribution presents the possibilities of applying abrasive water jet (AWJ) technology for multi-material micromanufacture. The working principles of injection and suspension AWJ systems are presented. Characteristics of this technology, such as the ability to machine virtually any kind of material and the absence of a relevant heat-affected zone, are given, especially those from which the production of microcomponents can benefit. A few attempts to miniaturize the AWJ machining process are described in the state-of-the-art preview. In order to develop and improve the AWJ as a microtool, a numerical simulation based on the finite element analysis is introduced to evaluate the effect of the size abrasive particles and the process efficiency of microsized AWJ. An ongoing project in which an improved mini AWJ cutting head is being developed, is presented. Finally, the possible fields of application are given, including a case study on the machining of miniaturized heat sinks.

Development of ice abrasive waterjet cutting technology

2017 ◽  
Vol 2 (81) ◽  
pp. 76-84
Author(s):  
J. Valentinčič ◽  
A. Lebar ◽  
I. Sabotin ◽  
P. Drešar ◽  
M. Jerman
Keyword(s):  
High Speed ◽  
Power Plants ◽  
Water Jet ◽  
Abrasive Waterjet ◽  
Abrasive Water Jet ◽  
Influence Of Process Parameters ◽  
Cutting Head ◽  
Ice Particles ◽  
Main Challenge ◽  
Awj Cutting

Purpose: Abrasive water jet (AWJ) cutting uses mineral abrasive to cut practically all materials. In ice abrasive water jet (IAWJ) cutting, the ice particles are used as abrasive. IAWJ is under development with the aim to bridge the gap in productivity between the abrasive water jet (AWJ) and water jet (WJ) cutting. It is clean and environmentally friendlier in comparison with AWJ, while its cutting efficiency could be better than WJ. Design/methodology/approach: The main challenge is to provide very cold and thus hard ice particles in the cutting zone, thus cooling the water under high pressure is utilized. Further on, two approaches to obtain ice particles in the water are studied, namely generation of ice particles in the cutting head and generation of ice particles outside of the cutting head and adding them to the jet similar as in AWJ technology. In this process it is essential to monitor and control the temperature occurring in the system. Findings: To have ice particles with suitable mechanical properties in the cutting process, the water have to be precooled, ice particles generated outside the cutting head and later added to the jet. The results show that, contrary to the common believe, the water temperature is not significantly changed when passing through the water nozzle. Research limitations/implications: The presence of ice particles was only indirectly identified. In the future, a special high speed camera will be used to study the influence of process parameters on ice particle distribution. Practical implications: IAWJ technology produces much less sludge (waste abrasive and removed workpiece material mixed with water) than AWJ technology which is beneficial in e.g. disintegration of nuclear power plants. IAWJ technology has also great potential in the food and medical industries for applications, where bacteria growth is not desired. Originality/value: The paper presents the latest achievements of IAWJ technology.

scholarly journals Research into the Disintegration of Abrasive Materials in the Abrasive Water Jet Machining Process

2021 ◽  
Author(s):  
Andrzej Perec
Keyword(s):  
Method Of Moments ◽  
High Speed ◽  
Water Jet ◽  
Machining Process ◽  
Abrasive Water Jet ◽  
Abrasive Particles ◽  
Cutting Head ◽  
Grain Distribution ◽  
Awj Cutting ◽  
Ward Method

The size and distribution of abrasive particles have a significant influence on the effectiveness of the cutting process by the high-speed abrasive water jet (AWJ). The paper deal with the abrasive materials disintegration intensity in AWJ cutting during the creation of the abrasive jet. An evaluation of the abrasive materials grabbed after forming in the cutting head was carried out and its grain distribution was evaluated. Used here the arithmetic, geometric and logarithmic method of moments and Folk and Ward method. The influence of abrasive concentration of abrasive materials as alluvial garnet, recycled garnet, corundum, and olivine on grain distribution was studied. A recovery analysis was also carried out and the recycling coefficient for each tested abrasive material was determined.

scholarly journals Impact of Preparation of Titanium Alloys on Their Abrasive Water Jet Machining

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7768
Author(s):  
Adam Štefek ◽  
Martin Tyč
Keyword(s):  
Titanium Alloys ◽  
Niti Alloy ◽  
Traverse Speed ◽  
Structural Features ◽  
Water Jet ◽  
Abrasive Water Jet ◽  
Abrasive Water Jet Machining ◽  
Declination Angle ◽  
The Impact ◽  
Awj Cutting

Several titanium alloys, i.e., grade 2 Ti, Ti6Al4V and NiTi alloy, prepared by selected deformation procedures were subjected to abrasive water jet (AWJ) cutting and subsequently analysed. The study describes samples’ preparations and respective material structures. The impact of deformation processing of the selected alloys on the declination angle during cutting, and the results of measurements of surface wall quality performed for the selected samples at the Department of Physics of Faculty of Electrical Engineering and Computer Science at VŠB–Technical University of Ostrava, are presented and discussed, as are also the influences of structural features of the processed titanium alloys on surface qualities of the investigated samples. The results showed that the highest resistance to AWJ machining exhibited the Ti6Al4V alloy prepared by forward extrusion. Its declination angle (recalculated to the thickness 10 mm to compare all the studied samples) was 12.33° at the traverse speed of 100 mm/min, pumping pressure of 380 MPa, and abrasive mass flow rate of 250 g/min.

Design and Fabrication of the FBR Fuel Disassembly System

2009 ◽  
Author(s):  
Toru Kitagaki ◽  
Masayuki Tasaka ◽  
Hidetoshi Higuchi ◽  
Kenji Koizumi ◽  
Hiroyasu Hirano ◽  
...  
Keyword(s):  
Technology Development ◽  
Laser System ◽  
Testing Machine ◽  
Cutting Condition ◽  
Energy Agency ◽  
Cutting Method ◽  
Fuel Pin ◽  
Cutting Operation ◽  
Mechanical Cutting ◽  
Cutting Modes

Japan Atomic Energy Agency (JAEA) has been developing a reliable disassembly system for FBR fuel reprocessing as a part of Fast Reactor Cycle Technology Development (FaCT). As FBR fuel pins are installed in a hexagonal shaped wrapper tube made of stainless steel, the fuel pins should be separated from the wrapper tube prior to the shearing process. JAEA has been developing the laser beam cutting method and the mechanical cutting method as the disassembly system. Although Fiber laser system showed a good cutting performance, it couldn’t completely avoid fuel pin damage and adhesion during the cutting operation. So we focused on the mechanical method to minimize such troubles. Two types of mechanical cutting modes have to be developed to realize the disassembly procedure, namely, the slit-cut for the wrapper tube and the crop-cut for the end plug region of the fuel pin bundle. To ensure disassembly technology of commercial reactor fuel assemblies, we designed and fabricated the testing machine of disassembly system having the cutting modes in engineering scale. We confirmed basic functions of this machine and improved its performance. We will soon demonstrate engineering operation by a series of disassembling and pin bundle handling procedure; separating fuel pins from wrapper tube, transferring them to the fuel magazine for shearing. Scattering of cutting dust cause machine troubles and transition of it to the dissolution process together with pins causes unknown problems. To resolve the problems, collection device of cutting dust will be tested and the cutting condition to make the disassembly easy to cut will be improved.

scholarly journals Influence of Steel Structure on Machinability by Abrasive Water Jet

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4424 ◽  
Author(s):  
Irena M. Hlaváčová ◽  
Marek Sadílek ◽  
Petra Váňová ◽  
Štefan Szumilo ◽  
Martin Tyč
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Mechanical Characteristics ◽  
Water Jet ◽  
Abrasive Waterjet ◽  
Abrasive Water Jet ◽  
Roughness Parameters ◽  
Steel Microstructure ◽  
Surface Roughness Parameters ◽  
Awj Cutting

Although the abrasive waterjet (AWJ) has been widely used for steel cutting for decades and there are hundreds of research papers or even books dealing with this technology, relatively little is known about the relation between the steel microstructure and the AWJ cutting efficiency. The steel microstructure can be significantly affected by heat treatment. Three different steel grades, carbon steel C45, micro-alloyed steel 37MnSi5 and low-alloy steel 30CrV9, were subjected to four different types of heat treatment: normalization annealing, soft annealing, quenching and quenching followed by tempering. Then, they were cut by an abrasive water jet, while identical cutting parameters were applied. The relations between the mechanical characteristics of heat-treated steels and the surface roughness parameters Ra, Rz and RSm were studied. A comparison of changes in the surface roughness parameters and Young modulus variation led to the conclusion that the modulus was not significantly responsible for the surface roughness. The changes of RSm did not prove any correlation to either the mechanical characteristics or the visible microstructure dimensions. The homogeneity of the steel microstructure appeared to be the most important factor for the cutting quality; the higher the difference in the hardness of the structural components in the inhomogeneous microstructure was, the higher were the roughness values. A more complex measurement and critical evaluation of the declination angle measurement compared to the surface roughness measurement are planned in future research.

Modeling and Optimization of Abrasive Water Jet Cutting of Kevlar Fiber-Reinforced Polymer Composites

2012 ◽  
pp. 262-286
Author(s):  
Tauseef Uddin Siddiqui ◽  
Mukul Shukla
Keyword(s):  
Quality Characteristics ◽  
Water Jet ◽  
Fiber Reinforced Polymer ◽  
Abrasive Water Jet ◽  
Multi Objective Optimization ◽  
Fiber Reinforced ◽  
Kevlar Fiber ◽  
Frp Composites ◽  
Reinforced Polymer ◽  
Awj Cutting

This chapter presents a detailed study of abrasive water jet (AWJ) cutting of thin and thick Kevlar fiber-reinforced polymer (FRP) composites used in transport aircraft and anti-ballistic applications. Kevlar composites are considered to be very challenging to machine using traditional techniques. Most of the research conducted in the area of AWJ cutting has been limited to single response optimization. However, in real life machining, the performance of a process/product demands multi-objective optimization (MOO). No work has been reported till now using different MOO techniques for AWJ cutting of Kevlar FRP composites. Experimental modeling of depth of cut and various design of experiments based single and multi-objective optimization studies are presented here. Statistical analysis of variance has been performed to rank the different process parameters and estimate their effects on various AWJ cut kerf quality characteristics. The studies conducted in this chapter are likely to prove beneficial to the AWJ community in performing modeling and simultaneous optimization of multiple quality characteristics.

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