Dimension Stone Cutting with AWJ Methods

2005 ◽  
Vol 498-499 ◽  
pp. 482-487 ◽  
Author(s):  
Guillermo Ruperto Martín Cortés ◽  
Wildor Theodoro Hennies ◽  
Carlos Tadeu Lauand ◽  
Francisco Rolando Valenzuela-Díaz

The application of high-pressure abrasive water jets (AWJ) has evolved quickly in some fields of engineering. At Polytechnic School, University of São Paulo, one application has particular interest that is the cutting of friable materials, as rock and ceramics. The main aspect in this field is the cut at the beneficiation process of end product in dimension stone plates. How much the cut of plates, by different kind of AWJ methods, was the research of a PhD work of one of the authors. The abrasive water jet equipment, installed in the Laboratory of Rock Mechanics of the Mining and Petroleum Engineering Department, was used. Some fundamentals considerations regarding, the employed single and multiple passes methods of AWJ to cut rocks, are discussed.

2021 ◽  
Vol 9 ◽  
Author(s):  
Xinzhe Zhang ◽  
Piotr Wiśniewski ◽  
Sławomir Dykas ◽  
Guojie Zhang

High-pressure abrasive water jet flushing (HPAWJF) is an effective method used to improve coal seam permeability. In this study, based on the theories of gas flow and coal deformation, a coupled gas-rock model is established to investigate realistic failure processes by introducing equations for the evolution of mesoscopic element damage along with coal mass deformation. Numerical simulation of the failure and pressure relief processes is carried out under different coal seam permeability and flushing length conditions. Distributions of the seepage and gas pressure fields of the realistic failure process are analyzed. The effects of flushing permeability enhancement in a soft coal seam on the gas drainage from boreholes are revealed by conducting a field experiment. Conclusions can be extracted that the gas pressure of the slotted soft coal seam is reduced and that the gas drainage volume is three times higher than that of a conventional borehole. Field tests demonstrate that the gas drainage effect of the soft coal seam is significantly improved and that tunneling speed is nearly doubled. The results obtained from this study can provide guidance to gas drainage in soft coal seams regarding the theory and practice application of the HPAWJF method.


Author(s):  
P. J. Borkowski ◽  
J. A. Borkowski

Novel method for the 3D shaping of different materials using a high-pressure abrasive water jet is presented in the paper. For the steering movement process of the jet, a principle similar to the raster image way of record and readout was used. However, respective colors of pixels of such a bitmap are connected with adequate jet feed rate that causes erosion of material with adequate depth. Thanks to that innovation, one can observe spatial imaging of the object. Theoretical basis as well as spatial model of material shaping including steering program is presented in. There are also presented experimental erosion results as well as practical examples of the object’s bas-relief made of metal.


2021 ◽  
pp. 2150031
Author(s):  
H. DENİZ ADA ◽  
MEHMET ERDEM ◽  
KADİR GOK

Today, conventional machining with chip or machining without chip machining manufacturing methods is used to bring to the desired dimensions sizes the machines and equipment used in the industry. However, non-traditional manufacturing methods are used in cases where traditional machining manufacturing methods are inadequate. Cutting with water jet which is one of the non-traditional manufacturing methods is commonly used in several fields of industry. Unlike traditional manufacturing methods such as turning and milling, not using of a physical cutting tool is among the advantages of the method. Abrasive water jet manufacturing method was started to be applied by adding abrasive particles in the water jet. Apart from the superior properties of the method, possible damages occur in the water jet nozzle due to processes such as cutting or drilling by applying high pressure. Erosion-corrosion is the leading damage among these damages. In this study, the erosion-corrosion in the nozzle caused by high-pressure water and abrasive during the abrasive water jet cutting process was simulated in the computer environment. In this paper, the erosion rate in the nozzle was calculated as 6,90E-06[Formula: see text]kg/m2[Formula: see text]s. This value was converted as 0,30[Formula: see text]mm (27,09[Formula: see text]mm for yearly) via developed software for 100[Formula: see text]h.


2016 ◽  
Vol 8 (3) ◽  
pp. 168781401663679 ◽  
Author(s):  
Can Kang ◽  
Haixia Liu ◽  
Xiuge Li ◽  
Ya Zhou ◽  
Xiaonong Cheng

2019 ◽  
Vol 2019 ◽  
pp. 1-18
Author(s):  
Xiaohui Liu ◽  
Ping Tang ◽  
Qi Geng ◽  
Xuebin Wang

It has been found that the impact performance of water jets can be changed by its properties, which include pressure, additive, and mode of jet. Thus, an abrasive water jet (AWJ) has been developed as a new method. However, there is little research on the effect of abrasive concentration on the impact performance of abrasive jets. Thus, the SPH method is used to establish an abrasive water jet crushing concrete model to study the effect of abrasive concentration on the impact force, concrete internal energy, abrasive particle distribution, crushing depth, and damage and crushing efficiencies under different concrete compressive strengths and abrasive densities. The results indicate that there is little effect of the abrasive concentration on the peak impact force under different compressive strengths and abrasive densities, while the mean impact force tends to increase linearly with the abrasive concentration. The internal energy of the concrete increases stepwise with the abrasive concentration under different compressive strengths and abrasive densities. The concentration of 10%∼20% is the rapid increasing stage. The crushing depth and damage efficiencies are all maximum at a concentration of 20% under different compressive strengths and abrasive densities. After the concrete was impacted by the water from the water jet, it is divided into rebounding particles and intrusive particles. The more the intrusive particles, the easier the concrete to be crushed and damaged.


2014 ◽  
Vol 556-562 ◽  
pp. 1126-1128
Author(s):  
Chao Kun Wei ◽  
Shan Shan Tang ◽  
Hao Yang

Currently, abrasive water jet technology is widely applied to cutting while it has been difficult in circular cutting, as travel mechanism is not easy to realize or the structure is too complex. To solve this problem, this paper presents a simple circular cutting device for high-pressure water jet technology. The cutting device completes cutting work by rotating clamping devices around the center thimble through electromotor. At the same time,the paper introduces the components of the circular cutting device and analyzes the reliability of the slider part by ANSYS.


Mechanik ◽  
2017 ◽  
Vol 90 (11) ◽  
pp. 997-999
Author(s):  
Rafał Kudelski

Quality of the technological part is one of the major problems of modern machine manufacturing. In many cases, components are manufactured from new construction materials with specific properties that are considered difficult to machining applying conventional technologies. Hence, to search for new technologies, including high-pressure abrasive water jet cutting in the context of the S355J2H steel elements manufacture, while maintaining the quality requirements of the machining, is the need. The results of tests on the accuracy of components made of S355J2H steel are presented as dependent on the water jet pressure, cutting feedrate and the amount of abrasive dozed, with constant element thickness. The accuracy of the design measure – regardless of dimensional accuracy – was the magnitude of the lateral sagging of the cut workpiece resulting from the specific mechanism of water jet removal mechanism.


2021 ◽  
Author(s):  
Naser Haghbin

Abrasive water jet technology can be used for micro-milling using recently developed miniaturized nozzles. This thesis develops methodologies to predict the shape of micro-channels milled using high pressure abrasive water jets, and presents a new high pressure abrasive slurry jet micro-machining process. Since abrasive water jet (AWJ) machining is often used with both the nozzle tip and workpiece submerged in water to reduce noise and contain debris, the performance of submerged and unsubmerged abrasive water jet micro-milling of channels in 316L stainless steel and 6061-T6 aluminum at various nozzle angles and standoff distances were compared. It was found that the centerline erosion rate decreased with channel depth due to the spreading of the jet as the effective standoff distance increased, and because of the growing effect of the stagnation zone as the channel became deeper. The erosive jet spread over a larger effective footprint in air than in water, since particles on the jet periphery were slowed much more quickly in water due to increased drag. As a result, the width of a channel machined in air was wider than that in water. It was also found that the erosive efficacy distribution changed suddenly after the initial formation of the channel. Then, a new surface evolution model was developed that predicts the size and shape of relatively deep micro-channels up to aspect ratios of 3 resulting from unsubmerged and iv submerged abrasive water jet micro-machining (AWJM) using a novel approach in which two different erosive efficacy expressions were sequentially applied. Since the channels produced by AWJM were found to be relatively wavy due to fluctuations in abrasive mass flow rate, a novel high pressure (water pump pressure up to 345 MPa) abrasive jet slurry micro-machining (HASJM) system was introduced by feeding a premixed slurry into the mixing chamber of a water jet machine with a micro-nozzle. Moreover, an existing model developed for AWJM abrasive particle velocities was modified and used to predict the particle velocity in HASJM, and then verified using a double disc apparatus (DDA). The HASJM system was then used to study the effect of entrained air in abrasive water jet micro-machining (AWJM) by performing experiments at the same particle velocity and dose for the two systems. The centerline waviness, Wa, of micro-channels made in SS316L and Al60661-T6 using HASJM were typically 3.4 times lower than those made with AWJM using the same dose of particles due to the more constant abrasive flow rate provided by the HASJM provided. The centerline roughness, Ra was approximately the same in both processes at a traverse velocity of Vt=4572 mm/min and a nozzle angle of 90°. For micro-channels of a given depth, the widths of those made with HASJM were 25.6 % narrower than those produced with AWJM, mainly due to the wider jet that resulted from the entrained air in AWJM.


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