PROCEEDINGS THIRD US. WATER JET CONFERENCE UNIVERSITY OF PITTSBURGH MAY 21 - 23 1985 EDITED BY DR. NEIL STYLER UNIVERSITY OF PITTSBURGH SPONSORED BY UNITED STATES BUREAU OF MINES UNIVERSITY OF PITTSBURGH WATER JET TECHNOLOGY ASSOCIATION ACKNOWLEDGMENTS For their help in organizing the conference, and the field trips, I would like to express my appreciation to: R. J. EVANS, CO-CHAIRMAN H. J. HANDEWITH J. N. MURPHY E. D. THIMONS F. D. WANG TEXT FOR THE OPENING COMMENTS by J. N. MURPHY Research Director Pittsburgh Research Center Bureau of Mines U.S. Department of the Interior Pittsburgh, PA THIRD U.S. WATER JET CONFERENCE, PITTSBURGH, PA MAY 21, 1985 On behalf of the Bureau of Mines, it is a pleasure to have the opportunity to participate in the Third U.S. Water Jet Conference, and may I commend the cosponsors for their interest and participation. Congratulations are in order for the Organizing Committee for assembling the excellent program. All who have contributed to the phenomenal progress made in this field in recent years can be proud of their contributions. The bottom line is, of course, the manner in which and the extent to which the technology is used in the field. And, of course, the extent to which it is used is ultimately the cost benefit of these technologies to the user. The Conference must and does consider the theoretical aspects of water jetting as well as engineering, field performance of different systems, and safety. The papers presented at the Conference will cover the use of water jets for cutting, drilling, and cleaning. The types of jets employed can be divided into three categories: jet-assisted mechanical cutting, modified jets (i.e., slurry jets, etc.), and pure (high-pressure) jets. If you consider water-jet-assisted cutting as an example, and if you were a mining operator or a tunnelling contractor, you might find any of the following attributes of significant interest: 20-to 50-pct reduction in cutting forces; 300-to 500-pct increase in bit life; significant reduction in machine vibration, dust, and noise; and improvement in the size distribution of your product (less fines). All of these attributes are potential benefits that can be realized by water-jet-assisted cutting. In fact, we have seen some commercial realizations of this technology on roadheading machines, where the Bureau has been pleased to participate in this pioneering effort. To date, there are over 20 water-jet-assisted roadheaders in use or on order. These promising results should not be interpreted to signify that all work is done relative to water-jet-assisted cutting. There is still an essential requirement for a better theoretical understanding of the mechanisms that produce these outstanding benefits which would permit more rapid optimization and, perhaps, improvement of the performance characteristics that have already been observed. Additionally, there are many engineering details required to implement this technology, including improved rotary seals and phasing systems. As we ask ourselves "What will the future he for water-jet-assisted cutting?" perhaps an analogy is helpful: A number of years ago if you wanted an automatic transmission for your automobile, it was necessary to special order this feature. Today, automatic transmissions are generally standard, and with some exceptions if one chooses not to have an automatic transmission, it is a special order. In 3 to 5 years, I believe water-jet-assisted cutting on mining equipment and tunnelling equipment will be a standard feature, and if you do not want it for your machinery, you will have to special order the machine without this feature. With so many apparent benefits for water-jet-assisted cutting, one must ask "Why should anyone consider the application of the modified jets or the high-pressure jets?" While the technological hurdles are greater for these approaches, the potential rewards are commensurate with the challenges, and we must pursue these technologies as well. While, in my opinion, it may take 5 to 10 years to see extensive utilization of modified and high-pressure jets, it is imperative that we press on. Considering the analogy used above, while I am convinced that water-jet-assisted cutting will be, like the automatic transmission, on every machine, the other water jet cutting technologies will at least initially be used on special applications; to keep with the automobile analogy, perhaps this technology is like the four-wheel drive, while not used everywhere, where it is needed you cannot do without it. For all of these areas safety must be of utmost concern; it is an essential part of the research, as well as the product engineering. This Conference provides the forum to exchange theory, engineering, field experience, and safety considerations of these technologies. May I extend to you my best wishes for a successful meeting and urge you to press on with the development and application of some of the most revolutionary mining and industrial technologies that we have seen in recent years. Please Note. This text is a scanned in version of the original. Because of some limitations in our programming the original pagination has been changed. Other than that we have tried to make the text a little more readable by increasing the spacing between paragraphs, but the text itself has been (subject to possible OCR misinterpretations) left as written. CONTENTS SESSION A: INDUSTRIAL AND CLEANING APPLICATIONS 1. Removal of Cement Lining From Oil Field Injection Lines With Waterjets. G.P. Zink, and J.E. Wolgamott ............................................... ............ ............................. 3 2. Operational and Maintenance Misconceptions of High Pressure Power Pumps. G.J. DeSantis .......................... ............... ............ ............... ............ ............................. 9 3. An Experimental Comparison of Commercially Available Steady Straight-Pattern Water Jetting Nozzles. M.J. Woodward ................... ............ ............... ............ ............... ............ ....................24 4. Ship Hull Cleaning with Self-Resonating Pulsed Water Jets. A.F. Conn, and G.L. Chahine .......................................... ............... ............ ....................34 5. Recommended Practices for the use of Manually Operated High Pressure Water Jetting Equipment. Water Jet Technology Association . ......................................... ............. ...... .........................49 SESSION B: THEORETICAL STUDIES AND ABRASIVE JETS 1. Successful Application of an Abrasive Water Jet To Cut Concrete Pavement Under Actual Field Conditions. M.J. Kirby, and S.R. Kramer ........................................ ............ ............... .......................67 2. An Abrasive Jet Device for Cutting Deep Kerfs in Hard Rock. G.A. Savanick, W.G. Krawza, and D. E. Swanson ................................................................ 79 3. Abrasive-Waterjet Deep Kerfing in Concrete for Nuclear Facility Decommissioning. M. Hashish, M. Halter, and M. McDonald ................................................... .......................97 4. Ultra High Velocity Water Jets. A.J. Watson, and C.J. Moxon ....................................... ............ ..... ......... .......................117 5. Investigation on Anatomy of Continuous Waterjet for Updating Jet Performance. C.S. Zou, L. Dang, X. Duan, and D. Cheng . ................................................ ........................ 132 SESSION C: MINING AND DRILLING I 1. Development and Basic Regularities of Waterjet Cutting Technology in China Coal Industry. B.Z. Tian, J.J. Sun, and C.L. Zou ................................................................ .......................147 2. High Pressure Water Jet Applications to Roadheaders. J. Straughan ......................... ............ ............... ............ ............... ............ ....................157 3. Test on the Application of Waterjets for Boom-Type Roadheaders in the German Hardcoal Industry. V. Mertens .......................... ............ ............................ ......... ............... .......................171 4. An assessment of Rotating High Pressure Water Jets for Drilling and Slotting of Hard Ore Bearing Rocks. M.M. Vijay, P.E., Grattan-Bellew .......................................... ...... ......... ...... ............................185 5. Cutting Trials With a Water Jet Assisted Longwall Coal Shearer. P.D. Kovscek, R.J. Evans, and C.D. Taylor ............................................ ......... ........................ 202 5. Technical and Technological Considerations in the Carving of Granite Prisms by High Pressure Water Jets. D.A. Summers, and M. Mazurkiewicz ................................ ......... ......... ...... ........................... 221 SESSION D: SPECIAL APPLICATIONS 1. Investigation of Ultra-Fine Coal-Disintegration Effect by High Pressure Water Jet. M. Mazurkiewicz ....................... ...... ............. .......... ...... ......... ................ ...... 231 2. Relationship Between Water Cannon Design, Pulsed Water Jet Anatomy and Rock Breaking Effect. D.Z. Cheng, G.L. Liang, C.X. Lu, and Y. Xu ................................................ ............................245 3. Computer Aided Engineering and Design of Cumulation Nozzles for Pulsed Liquid Jets. W.C. Cooley .................... ...... ............. ...... ............. ........ ...... ................................................ 258 4. Water Jet Cavitation Performance of