WATER JET CONFERENCE - Waterjet Technology Association

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<strong>JET</strong>-MINER SURFACE AND IN-SEAM TRIALS RUN BY BERGBAU-FORSCHUNG GMBH, GERMANY Dr. -Ing. E. H. Henkel Department And Test Side Coal Winning, Conveying, Face-End-Systems Bergbau-Forschung GmbH, Federal Republic of Germany ABSTRACT Following to a detailed discussion of the underground trials run with the experimental version of the Jet-Miner, the development of the prototype is delineated. The prototype design, the drive units for high pressure water supply and haulage, the array of the high pressure water cutting heads, the water and energy supply system as well as integrated operation with the other coal face equipment are explained. Subsequently, initial results of surface trial are discussed, the preparations rid lay out with respect to underground operation of the Jet-Miner are described. Underground trials under production conditions at Lohberg colliery are undertaken. The measured results relative to technical data, winning performance and quantity of dust, particle-size distribution and moisture content of the coal are described. INTRODUCTION The average of the worked seam thicknesses in German hard coal mining which today is 1.9 m will be reduced in the future to approximately 1.5 m. This requires the development of heavy duty coal winning machinery specially designed for use in seam thickness ranging between 1.0 m and 1.5 m. The coal ploughs used today in seams of such thickness do not meet the requirements is all respects, and consequently new developments, especially on the basis of plough technology, are pushed ahead more vigorously. The following targets are set for winning machinery to be used in hard coal and in seams of 1.0 to 1.5 m thickness: • high winning performance in hard coal • large-sized lumps (improved quality) • cutting into adjacent rock • less dust. The development of the Jet-Miner, a winning machinery using high-pressure waterjets for cutting, constitutes an important step towards the above-mentioned targets. The co-operation between M.A.N.-GHH Sterkrade, Ruhrkohle AG, and Bergbau-Forschung GmbH resulted first in an experimental unit by which the basic suitability of the techniques implied were proven (Refs. 1, 2, 3). 236
Based on knowledge gained throughout the trials a first Jet-Miner prototype was constructed by M.A.N.-GHH-Sterkrade. This prototype is supposed to meet the requirements defined to a very great extent. The following chapters will describe the development of this prototype, the surface trials run and the underground operation. UNDERGROUND TRIALS RUN WITH THE EXPERIMENTAL VERSION Trial Face Following to the good results of the surface trials run with the experimental version, an experimental coal face was established at Lohberg colliery in seam N (4). The experimental coal face was of 50 m length and of 1.6 m of seam thickness. According to its strength the coal was categorized as "difficult to plough" (Fig. 1). In comparison to the configuration run in the surface trials, the machine was slightly modified; the key data reads: Machine under tests: Operation voltage U = 1000 V Installed power for the pumps P = 300 kW Flow (max.) V = 226 l/min Water pressure p = 70 MN/mZ Total mass m = 23.000 kg Hydrostatic haulage drive Installed power p = 3 x 80 kW The measuring program covered the following parameters: • Cutting force of a cutting F s • Pulling force (chain) F k • Pressure of the hydro-motor P H • Travelling speed In addition coal samples for determination of particle-size distribution and moisture content were taken, and furthermore dust and noise measurements were carried out. Test Results From the coal-winning point of view the experimental version worked quite satisfactorily from the very beginning. The coal face was undercut smoothly by the oscillating high-pressure waterjets and subsequently broken off by the cutting heads. The coal face did not exhibit any cutting or grinding traces caused by the mechanical tools. This meant that the coal, as envisaged, was cut exclusively by the waterjets and then broken off by the cutting heads. A further proof for this phenomenon is the fact that after the tests the cutting heads exhibited no wear and in particular no wear imputable to mechanical cutting work. 237
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Proceedings of the Second U.S. WATE
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Visualization of the Central Core o
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A Status Report on the Conceptual D
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SESSION 7 - CIVIL & INDUSTRIAL Chai
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Cutting Hard Rock With Abrasive-Ent
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frictional and piping component rel
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R = a1 ⋅ A1 A2 a2 I = 2H o Q o
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attenuation of the output. The tran
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Figure 1. Branch System Modulator F
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Figure 5. Modulation Response for B
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Figure 9. Modulation response for s
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can be used for any form of input.
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with a cylindrical shape to the jet
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m/s. The range of power found from
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Figure 3. Power vs nozzle diameter
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Figure 5. Frequency vs length of th
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NAME: Gerald Zink COMPANY: StoneAge
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modulatornozzle assembly. The ordin
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DISCUSSION OF FLUID MECHANICS The i
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This process serves to protect the
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For test purposes, these concrete b
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REFERENCES CITED 1. Barker, C. R.,
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FIGURE 4. INNER CORE OF PERCUSSIVE
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FIGURE 9. EXAMPLE OF HIGH-PRESSURE
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NAME: John E. Wolgamott COMPANY: St
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THE FOCUSED SHOCK TECHNlQUE FORPROD
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The reflected wave is thus also cyl
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neglected. The introduction of a co
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DISCUSSION NAME: George Savanick CO
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H’ mean shape factor Hj theoretic
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Required streamline curvature at th
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2 x 2 ≅ ( e − 2 p + w)/k2 (2-8)
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eliminating 2 n r 2 from equations
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approximation to the actual flow si
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skin friction coefficient but are c
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where: (H) = A1H 3 + A2H 2 + A3H +
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effect (< 0.5%) on coefficients of
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TABLE 5 Rei x 10 5 β 3 4 5 6 Po Po
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TABLE 6 D(mm) d o(mm) L t(mm) L f(m
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expanding rather than contracting a
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25. Weber, H.E., 1978, Boundary lay
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Figure 5. Wall velocity distributio
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Figure 9. Effect of nozzle design o
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Figure 12. CA+T Design Philosophy.
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Figure 16. Effect of inlet b 1 cond
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Figure 20. Relaminarization at nozz
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Figure 24. Pressure decay data. 88
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VISUALIZATION OF THE CENTRAL CORE O
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DISCUSSION Although employing the i
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5. Lambert, J. H., 1760, Photometri
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Figure 6. Spectral sensitivity curv
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NAME: W.C. Cooley COMPANY: Terraspa
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INTRODUCTION Pulsed liquid jets sho
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y=X ∨ P A dy = p p A p 2 (L c y=0
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Using equation (15), the value of X
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Thus about the first 10% of the dri
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Many design cases, including those
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surface spall occurred, resulting i
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Figure 3. Chamber pressure at pisto
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Figure 7. Effect of nozzle area rat
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Figure 11. Extrusion device schemat
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Figure 15. Typical chamber pressure
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DISCUSSION NAME: W. C. Cooley COMPA
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material which are, in turn, affect
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the water jet. This method was not
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where h is the depth of penetration
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obtained during this phase of the i
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observed that the smallest depth of
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Figure 2. Idealized Relationships b
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Figure 6. Penetration as a Function
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DEVELOPMENT OF VARIABLE DELIVERY TR
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THE STRUCTURE AND FUNCTION OF THE P
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The injection pressure can be contr
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ACKNOWLEDGEMENTS The authors gratef
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Figure 4. Theoretical required powe
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Figure 9. Variation of efficiency w
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THE "SKIPJACK" SEWER CLEANING NOZZL
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HYDRO-BLASTING SAFETY C.W. Adaway,
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Remember, your Hydro-Blasting work
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horizontal, sometimes vertical, and
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Figure 2. Safety Gear Figure 3. Tub
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DEVELOPMENTS IN CLEANING COKE OVEN
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causing chain breakages and the scr
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was encountered, then the rotation
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(C) Capital Expenditure: Material i
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Figure 9. Swivel coupling Figure 10
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OPTIMIZING JET CUTTING POWER FOR TU
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PRESSURE DROP (psi) ELEMENT Cv @10
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power output. Undersized nozzles re
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Subscripts n - Nozzle p - Pump t -
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Figure 1. Cutting effect as a funct
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CONSIDERATIONS IN THE COMPARISON OF
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pressure can be lowered to perhaps
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Figure 2: Fan jet issuing from a no
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DISCUSSION NAME: John Griffiths COM
Page 192 and 193: where Q = Flow rate - gpm D = Jet O
Page 194 and 195: Again, not limited to Newtonian flu
Page 196 and 197: REFERENCES 1. Brown, R.W. and Loper
Page 198 and 199: Table 2. Jet Cleaning Speeds and ot
Page 200 and 201: ANSWER: The utilization of the stat
Page 202 and 203: complexity and short component life
Page 204 and 205: Figure 4, for ap values ranging fro
Page 206 and 207: Decontamination Methods for rapidly
Page 208 and 209: a. “PULSER” b.”ORGAN-PIPE”
Page 210 and 211: Figure 5 - Removal rate for various
Page 212 and 213: DISCUSSION NAME: David A. Summers C
Page 214 and 215: DRILLING BORE HOLES IN COAL MINES U
Page 216 and 217: pile could not be judged as represe
Page 218 and 219: DISCUSSION NAME: David Summers COMP
Page 220 and 221: HYDRAULIC MINING EXPERIMENTS IN AN
Page 222 and 223: The monitor was fed pressurized wat
Page 224 and 225: The IH rig was considered to be sup
Page 226 and 227: REFERENCES 1. Okhrimenki, V. A., A.
Page 228 and 229: Figure 2. Jet cutting sandstone at
Page 230 and 231: Figure 5. Schematic plan view of In
Page 232 and 233: Figure 7. Suction Box. 226
Page 234 and 235: USE OF HIGH PRESSURE WATER JETS FOR
Page 236 and 237: flame torch to cut this block, redu
Page 238 and 239: the order of 360 rpm. Under these c
Page 240 and 241: Figure 3. Slot cut by jet at 11 o s
Page 244 and 245: The hydraulic drive of the haulage
Page 246 and 247: The surface trials had have the obj
Page 248 and 249: Figure 2. Experimental version. Fig
Page 250 and 251: Figure. 7 Jet-Miner prototype Figur
Page 252 and 253: SOME PATTERNS OF TECHNOLOGY TRANSFE
Page 254 and 255: Development of High Pressure_Techno
Page 256 and 257: configurations, the design of an op
Page 258 and 259: and public sectors. After a haitus
Page 260 and 261: Souder, W.E. and Evans, R.J., "The
Page 262 and 263: Figure 5. Technological achievement
Page 264 and 265: Table 3. Perceived disadvantages of
Page 266 and 267: already been, or is being applied w
Page 268 and 269: Using the requirements profile and
Page 270 and 271: ant hose combination, a guiding sys
Page 272 and 273: HYDRAULIC MINING TESTS Site selecti
Page 274 and 275: SAFETY All operations were carried
Page 276 and 277: TABLE V. Categories of Jet Mining D
Page 278 and 279: Figure 2. Generalized geologic prof
Page 280 and 281: SECONDARY FRAGMENTATION WITH WATER
Page 282 and 283: do possess a maximum point (Fig. 8)
Page 284 and 285: Figure 4. Rossin-Rammler plot. Figu
Page 286 and 287: Figure 8. Non-dimensional plot for
Page 288 and 289: HYDRAULIC COAL MINING SYSTEM Typica
Page 290 and 291: Figure 4. (From ref. 1) DISCUSSION
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INTRODUCTION Developing an unique t
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The coefficients "b " in Eq. (1) ca
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By the end of 1982, a total of more
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Figure 4. Cutting ability of swing-
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Figure 10. An operating performance
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for an abrasive, the abrasive parti
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the particles, while at slower spee
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to break away the remaining segment
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Table 1. Concrete saw technology. T
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NAME: Tom Brunsing COMPANY: Foster-
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FEASIBILITY STUDY OF CUTTING SOME M
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hydraulic power required to cut thr
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pressure was varied from 103 to 310
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2.1 Heading and gutting fresh cod f
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Figure 5. The cuts surface of a blo
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Figure 17. Cuts made across the cla
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JET NOTCHING USED IN THE CONSTRUCTI
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Bottom notch diameter was determine
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σ H = in-situ stress in the horizo
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Figure 3. Final block displacement.
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Figure 8. Comparison of Slurry Pump
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THE FURTHER DEVELOPMENT OF AN UNDER
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use taps or hydrants. To achieve th
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supply line. It was determined that
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The rotating head requires major mo
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Figure 4. System field test set-up
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Figure 10. Bentonite drilled clay s
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MECHANICAL TOOLS Cutting Tool Energ
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Ψ = cos −1 ⎧ ⎪ ⎪ ⎨ ⎪
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mode also contributes to chip flush
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NAME: Simon Johnson COMPANY: Newcas
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ROLLER TOOLS COMBINED WITH HIGH-PRE
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Various designs and applications ar
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Figure 1. Full-face tunneling machi
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Figure 11. roadway profile cutting
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Figure 19. High-pressure water jet
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DESIGN AND OPERATION OF TWO LARGE-S
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The hydraulic system for the thrust
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Results of Trial Tests As part of m
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cutting rates, degree of bit wear,
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Overall approximate Weight: Basic M
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Figure 5. 3 ft. diameter laboratory
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nozzle diameter and cutting speed w
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2. Cutting Speed The influence of c
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energy it effects an increase in me
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Tip angle (degrees) 87 Off-set angl
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Figure 5. Figure 6. Figure 7 Figure
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Figure 17. Figure 18. Figure 19. Fi
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SCHEMES OF COAL MASSIF BREAKAGE BY
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out thoroughly an efficient scheme
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Research analysis has proved that t
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DEPENDENCE OF POWER INDICES OF COMB
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The experiments have shown how the
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K Ay = coefficient correcting for f
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Figure 1. Schemes of combined break
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Figure 5. Dependence of specific en
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Figure 12. Percentage of grade R -6
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Figure 1. Particle size analysis. T
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NAME: Dr. Henkel COMPANY: Bergbau-F
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presented. This study, of course, i
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identifying a general trend for the
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Effect of Abrasive Hardness, Shape
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In some situations, especially in c
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Figure 1. Abrasive waterjet nozzles
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Figure 8. Effect of standoff distan
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Figure 13. Abrasive waterjet cuts i
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CUTTING WITH ABRASIVE WATERJETS M.
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3.3 Abrasive Feed Systems For abras
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Because of the large number of infl
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due to wear. Although actual operat
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from this new technology. Table 2 l
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Table 1. materials cut by abrasive
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Figure 1. Abrasive waterjet nozzles
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a) kerfs in mild steel b) S.S. 15.5
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a) circle cutting in glass b) lamin
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DISCUSSION NAME: Andrew F. Conn COM
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CUTTING HARD ROCK WITH ABRASIVE-ENT
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slurry nozzle. Testing at water pre
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DISCUSSION OF TEST RESULTS Jet Conf
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materials. The flexibility in nozzl
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pressure can be wiped out if diffic
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9. Maurer, W.C., and Heilheckler, J
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Figure 5. Effect of abrasive feed r
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Figure 9. Accumulated depth of mult
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Figure 13. Close-up view of quartzi
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ABRASIVE INJECTION USAGE IN THE UNI
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sudden changes in the feed rate eff
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or the abrasive must be manually to
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clog; there not being sufficient ar
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CODE OF PRACTICE FOR THE USE OF ABR
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Figure 5. Water abrasive cleaning h
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Figure 15. 360 0 abrasive pipe clea
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ECONOMIC CONSIDERATIONS IN WATER JE
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Other criteria to be considered in
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3 MANUAL METHODS OF JET CLEANING &
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contractor with old, unsafe, equipm
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Figure 1. Showing the increased cos
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Figure 8. Automatic tube bundle cle
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ackground to the subsequent coopera
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The molecules of SUPER-WATER posses
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shaken just before use. SUPERWATER
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26. Bednarz, L.P., "Effects of Poly
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