Read Measurement of Vertical Pressure Generated from Shaped Charge Explosive text version

Measurement of Vertical Pressure Generated from Shaped Charge Explosive

The data discovery from this ACMLRP is key to a body of research that is being conducted to find the solution to the "orange cloud" in surface coal mining. Picture 1

Deflagration produces orange nitrogen dioxide smoke. Detonation would produce colorless carbon dioxide gas.

Simply stated, there are two dominant chemical reactions possible when ammonium nitrate/fuel oil (ANFO) based blasting agent is ignited: detonation and deflagration (Equation 1 & 2). The undesirable chemical reaction that causes the Nitrogen Dioxide (Picture 1) formation is an environmental and health concern to the State of Wyoming, which can be resolved by controlling parameters of the borehole and blasting agent.

Detonation of ANFO (4,750 oF)

3 NH4NO3 + [-CH2-]n--------- CO2 + 3 N2 + 7 H2O

Equation 1

Deflagration of ANFO (850 oF)

3 NH4NO3 + NH4NO3 ------ 2 NO2 + 3 N2 + 8 H2O

Equation 2 Industrial Alchemy Charles R Barnhart

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10/4/2004

One of the problems with controlling the parameters of the blast is that the industry does not have all the tools they need, which has lead to the creation of a shaped charge detonation system (Drawing 1).

Plastic Capsule

The design dimensions and configuration of the shaped charge detonation system for the injection molding process. Drawing 1

A plastic capsule has been engineered to take the power of a conventional 1-pound Pentolite booster and amply the energy. The magnitude of the Pentolite booster and the shaped charge detonation system were compared by a sophisticated photographic method called streak testing. MREL Explosives Products Limited performed the streak testing on five capsules and five Pentolite boosters to compare the pressure and shock attenuation properties of each. The streak test consists of flashing light through water and exploding the test charge into the water such that the water becomes opaque. The time and duration of the opacity is captured on a strip of film that is spun in a drum at 1,000,000 revolutions per minute. This produces a streak on the film (Film 1), which is then turned, into a graphical data. The flash is produced by a cardboard cylinder filled with argon gas that is light off with a 1-pound Pentolite booster (Picture 2) just 1 millisecond before the test charge is ignited with a 1-pound Pentolite booster. Industrial Alchemy Charles R Barnhart

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Streak Test of Capsule

The shadowed image below the capsule is a 1-pound Pentolite booster hanging freely in the argon filled cylinder, which will become the flash bomb. The capsule is suspended two inches deep in the water filled glass tank. The capsule is fitted with a 1-pound Pentolite booster, which will ignite the 25 pounds of emulsified blasting agent inside the capsule. The shock wave from the explosion of the capsule will case the water to become opaque, which is recorded on a film as a black streak. Picture 2

Streak Film of Capsule Test

The view as seen through the streak camera is on the left side of the film. The image inverted such that the capsule is on the bottom of the film. The 1 millimeter wide black streak that runs at a 6-degree angle across the film is the data derived from the steak test. Film 1

25# Shaped Charge Steak Test

Picture 4 Industrial Alchemy Charles R Barnhart

1# Pentolite Booster Streak Test

Picture 5

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The conclusions of the streak test for the shaped charge initiated with a one pound Pentolite booster (Picture 4) and for the 1 pound Pentolite booster alone (Picture 5) are reported in the MREL report as follows:

Average Castmax 240 220 200 180 Pressure (Kbar) 160 140 120 100 80 60 40 20 0 0 50 100 Distance (mm) 150 200 250 Average Pentex

Graph 1: COMPARISON OF SHOCK PRESSURE IN WATER AS A FUNCTION OF DISTANCE FOR THE CASTMAX AND PENTEX PRIMERS. "This investigation has evaluated the detonation pressure and shock/pressure transmission characteristics of the CastMax booster system, and compared these properties with the pressure characteristics of a commercial Pentolite primer used extensively in the mining industry. Measured detonation pressures for both the CastMax booster (filled with emulsion) and the Pentolite primer compare well with accepted literature and/or calculated detonation pressures. As expected, the detonation pressure for the Pentolite primer (220 kbar) is much larger than the detonation pressure of the emulsion (95 kbar). However, it is clear that larger pressures are transmitted to greater distances in the acceptor medium (water) for the CastMax booster than for the Pentolite primer. At a distance of 2 inches (50 mm) the pressure from the CastMax is of the order of 26 kbar vs. 20 kbar for the Pentolite primer. At distances of 4 inches (100 mm) and 6 inches (150 mm), the pressure differential increases: 17 vs. 7 kbar and 14 vs. 3 kbar respectively. The ability of the CastMax booster to transmit significant shock pressures to a much greater distance in the acceptor charge should result in an increased capacity for shock initiation of the acceptor charge. The coupling of this detonation property with the increased amount of hot detonation gases, and larger shock surface associated with the CastMax booster, provides every indication that the CastMax booster should allow for easier initiation of bulk explosives in the borehole." The streak test clearly demonstrates that pressure from the end of the shaped charge detonation system is significantly greater and longer in duration than from the end of a Pentolite booster

Industrial Alchemy Charles R Barnhart

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10/4/2004

alone (Graph 1). This data can then be extrapolated to indicate that the shaped charge can be used to bring the borehole-blasting agent to detonation more quickly than the booster alone.

Capsule in Borehole

The shaped charge detonator system is designed to span as large a diameter of the borehole as possible. The 1pound Pentolite booster in the bottom of the capsule initiates the 25 pounds of protected blasting agent that then discharges a supersonic fireball of heat and pressure to ignite the entire circumference of the borehole-blasting agent. Drawing 2 Not only does the capsule shape and enhance the booster's energy, it also guarantees that the first blasting agent initiated by the booster has been protected from wetting, crystallization, absorption and/or separation. The bottom of the borehole is an unknown environment and quite often has the very worst blasting agent in the borehole so it is important to supply some guaranteed that the booster contacts noncompromised blasting agent immediately upon initiation.

Pentolite versus Shaped Charge Detonation System in Borehole

Supersonic fireball of heat and pressure from capsule is pointed the right direction in an angled borehole and puts the energy further up the borehole than does the Pentolite booster. Drawing 3 Industrial Alchemy Charles R Barnhart

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The capsule also acts to get the booster off of the borehole wall in the angled holes (Drawing 3) so that when exploded it does not fracture the wall through to the next borehole and cause it to be compromised. Any measure of control that can be applied to the initiation of the borehole will help stop deflagration.

MicroTrap VOD Data (H1)

Velocity of Detonation in Cast Blast Borehole

The VOD starts at 6,120 feet per second for 2 milliseconds, the fireball spreads to the circumference of the borehole and the VOD climbs to 10,440 ft/sec. At 60 feet up the borehole the detonation reaction completely takes over and the VOD reaches steady-state-velocity at 20,400 ft/sec. Graph 2

150

125

20,630 ft/s

Di 100 st an ce (ft) 75

20,400 ft/s

18,650 ft/s

50

VOD = 16,690 ft/s VOD = 6120 ft/s

VOD = 10,440 ft/s

25

0 -1 0 1 2 3 4 Ti me (ms) 5 6 7 8 9

Powerful borehole initiation has been identified as one of the controllable parameters to obey in achieving maximum VOD; plus the force of powerful initiation influences other parameters like confinement. Any blasting practice that increases the VOD reduces the likelihood of deflagration and, consequently, the amount of "orange smoke" produced. It is obvious from the VOD trace in Graph 2 that there can be some degree of deflagration occurring before the borehole reaches detonation velocity, even if the blasting agent is in good condition. The data starts out at 6,000 fps, climbs to 10,000 fps and finally reaches 20,000 fps for more than 60% of the blast. To minimize this slow start, the reaction needs to instantaneously initiate the entire circumference of the borehole with as much energy as possible. The source of initiation is one of the most important, yet underrated, factors in eliminating deflagration. The booster needs to be positioned in non-compromised blasting agent that is sensitized to a minimum VOD of 18,000 fps. Control of these factors will maximize the VOD at the very onset of the chemical reaction and decrease the possibility of deflagration. Industrial Alchemy has designed the CastMaxTM shaped charge detonation system that is filled with 25 pounds of high-energy emulsion. The plastic capsule's contents are protected from every unknown element at the bottom of a borehole that can compromise the integrity of the blasting agent surrounding the booster. When the booster is initiated, it ignites the shaped charge such that the discharge from the end of the CastMax is like a cannon blast aimed up the diameter of a 10 5/8" powder column. This ACMLRP demonstrates that the shaped charge does work to increase the energy of the booster as predicted and further full-scale experimentation with the capsule is warranted. Industrial Alchemy Charles R Barnhart

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10/4/2004

Average Castm ex

300

Average Pentex

250

200

Distance (mm)

150

100

50

0

0

10

20

30

40

50 Time (usec)

60

70

80

90

100

Graph 2: COMPARISON OF SHOCK WAVE TRAVEL IN WATER FOR THE CASTMAX AND PENTEX PRIMERS.

Industrial Alchemy Charles R Barnhart

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10/4/2004

Table 1. Castmex data used in Graph 1 and Graph 2.

Castmex-1 Time (usec) 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 55 60 65 70 75 80 85 90 Distance (mm) 0 Pressure (Kbar) 0 Time (usec) Castmex-2 Distance (mm) 0 Pressure (Kbar) 0 Time (usec) 0 Castmex-3 Distance (mm) 0 Pressure (Kbar) 0 Time (usec) 0 Castmex-4 Distance (mm) 0 Pressure (Kbar) 0 Time (usec) 0 Castmex-5 Distance (mm) 0 19.9571429 26.19375 Pressure (Kbar) 0 54.701545 46.0178529 (mm) 0 Average Distance Pressure (Kbar) 95

11.7647059 31.2038111 18.0995475 25.0884385 23.0769231 21.8765149 28.0542986 19.9267259 33.4841629 18.5279218 38.0090498 17.3669766 43.438914 48.8687783 16.4005962 15.637171

11.3174684 58.6431022 16.4617722 43.7882925 24.6926582 36.2502019 30.8658228 31.6978466 37.0389873 28.3736619 42.1832911 25.9386761 49.3853165 24.0713636 55.558481 22.5228849 62.7605063 21.1889813 69.9625316 20.0582711 76.1356962 19.0758409 80.2511392 18.2044523 85.395443 17.4179368 91.5686076 16.7526749 96.7129114 16.1138041 101.857215 15.5565053 108.03038 15.0370341 113.174684 14.5589596 119.347848 14.1133666 123.463291 13.706673 128.607595 13.3243901 133.751899 12.9670225 138.896203 12.6291826 144.040506 12.3116865 148.155949 12.0125396 159.473418 11.3437404 170.790886 10.7498976 183.137215 10.2176507 194.454684 9.74584743 204.743291 9.32120542 216.060759 8.9375709 226.349367 8.58073921 237.666835 8.25716734

11.9428571 82.0039536 20.1142857 60.6214209 28.2857143 50.3294074 35.8285714 43.7805172 42.7428571 39.4549024 50.2857143 36.0245503 56.5714286 33.3283219 63.4857143 31.2477812 69.1428571 29.3964042 76.0571429 27.7723392 82.9714286 26.4240763 90.5142857 25.3131989 97.4285714 24.2457632 103.714286 23.2760194 111.257143 22.4293958 117.542857 21.6897782 123.828571 20.9771061 130.114286 20.3532202 137.028571 19.7224464 142.685714 19.1571949 148.342857 18.6645719 154 158.4 18.1795413 17.7069042

15.5915179 66.3458143

12.6541373 59.5491703 18.6581871 46.0499242 25.5622614 38.6184943 31.6388473 33.9539075 37.8273277 30.6167624 44.157237 28.0877488 50.2898746 26.1371442 56.3224398 24.5200346 62.2276054 23.1212691 68.4042636 21.9120835 74.0822055 20.9356579 79.3753237 20.0463613 85.3065889 19.2385453 91.6497568 18.5223882 97.7381649 17.8688484 103.286043 17.2828008 109.247051 16.7441646 114.794929 16.2503555 120.686836 15.7719948 125.976271 15.3445523 130.828932 14.9544035 136.26246 14.5810852 141.296117 14.2270981 146.460607 13.8975551 151.436984 13.5876446 164.180391 12.880445 176.365555 12.2570907 188.879491 11.7060034 200.241059 11.2105242 211.006044 10.7695961 222.505815 10.3540888 232.957743 9.97998138 243.734759 9.64782056

31.8066964 40.4105402 38.0433036 36.1105634 46.1508929 33.0207924 51.7638393 30.7482951 57.3767857 28.6723013 63.6133929 26.9150588 69.2263393 25.4005473 72.9683036 24.3464892 77.9575893 23.2119009 84.1941964 22.2314554 91.678125 21.3745009 97.9147321 20.5856338 104.151339 19.8501182 111.011607 19.2058371 117.248214 18.5821438 124.108482 17.9887885 130.96875 135.958036 148.43125 17.4925139 17.029107 16.1588922

53.3936652 14.9846322 58.3710407 14.4171763 64.2533937 13.8962251 68.7782805 13.4558933 74.2081448 13.0590256 79.638009 12.6863577 85.0678733 12.3465598 89.5927602 12.0348014 94.1176471 11.7566809 98.6425339 11.5070984 102.262443 11.2633777 106.78733 110.40724 11.0218274 10.7995451

114.479638 10.6129605 119.457014 10.4134135 123.076923 127.60181 10.237309 10.0642773

142.818304 16.5648165 154.667857 15.7431765 160.904464 15.3682915 175.872321 14.5295493 190.216518 13.7635844 203.313393 13.1295304 214.539286 12.5362896 225.765179 12.0013114 236.991071 11.5187653 247.593304 11.0704164 258.819196 10.6698637

164.057143 17.2980483 169.085714 16.9054701 182.914286 15.9739638 194.228571 216.857143 15.191077 13.8425 206.171429 14.4661009 227.542857 13.2680346 236.971429 12.7381184 247.028571 12.2666952 255.828571 11.8667409

138.461538 9.67452633 150.226244 9.32380371 162.895928 9.01073151 175.113122 8.71745963 185.972851 8.48783284 200 8.22190053 210.859729 8.00207477 222.624434 7.79751032

Table 2. Pentex data used in Graph 1 and Graph 2.

Pentex-1 Time (usec) 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 55 60 65 70 75 80 85 90 95 11.2104938 86.3498082 21.4018519 50.1098171 28.5358025 36.7943452 35.1601852 29.0086664 42.8037037 23.9311492 50.4472222 20.3511561 55.5429012 17.5103776 60.1290123 15.4757668 65.7342593 13.7821423 70.8299383 12.3372941 75.9256173 11.1651678 81.0212963 10.130216 86.1169753 9.27346647 90.1935185 8.49769278 94.2700617 7.81996482 98.3466049 7.24215197 101.404012 6.69595864 106.499691 6.2164655 110.066667 5.77057877 114.14321 5.35844038 117.710185 4.98243673 121.27716 4.66297155 125.353704 4.36216312 128.920679 4.07371755 132.487654 3.81065426 141.659877 3.22260036 150.832099 2.72074437 159.494753 2.28727099 168.157407 1.9198418 177.32963 1.59082334 185.992284 1.30122201 194.14537 1.04940214 202.298457 0.81725238 210.451543 0.60825794 10.8254613 91.1183306 21.1354244 54.0814671 30.4143911 39.656208 38.6623616 31.9423515 45.8793358 26.4919783 51.5498155 22.3005569 57.7357934 19.6341392 63.4062731 17.3815234 69.0767528 15.5441552 72.6852399 14.0131114 77.8402214 12.7151575 82.4797048 11.6434191 87.6346863 10.6973244 92.2741697 9.88955704 96.398155 9.14335061 101.037638 8.48557517 105.161624 7.91081127 109.801107 7.36482544 113.925092 6.8990327 118.049077 6.46595052 122.173063 6.05557382 126.297048 5.69758133 130.421033 5.35789848 134.545018 5.04336812 137.638007 4.74629487 147.94797 4.08961245 155.680443 3.55065543 164.95941 3.08070639 174.753875 2.6644663 183.517343 2.29800038 192.79631 1.97702945 201.04428 1.69736239 13.5847191 98.2640921 23.1739326 58.8645177 31.1649438 41.5183438 38.3568539 32.5685864 45.548764 26.3866078 52.7406742 22.2263281 59.1334831 19.0668198 64.727191 16.6830667 70.3208989 14.7158339 74.3164045 13.134 79.9101124 11.7737971 83.905618 10.6627585 89.4993258 9.68632353 93.4948315 8.83675303 96.691236 8.07686332 101.485843 7.41733776 105.481348 6.83423446 110.275955 6.31005802 115.070562 5.82296204 118.266966 5.38962889 123.061573 4.99444056 126.257978 4.62917364 131.052584 4.30606574 134.248989 3.9987252 138.244494 3.70903164 147.833708 3.08725794 155.824719 2.55711346 165.413933 2.10958978 171.806742 1.71847203 9.525 67.9140688 19.05 40.7338724 27.6225 30.1173279 34.76625 24.2030502 40.48125 20.282315 45.72 17.2440498 50.4825 15.1354907 56.1975 13.3892865 61.43625 11.92861 66.19875 10.7980493 70.485 9.75740917 75.2475 8.92580016 79.53375 8.18947507 84.29625 7.5694341 87.63 6.98428734 91.44 6.47983153 96.2025 100.0125 5.9875611 5.5899693 13.0628571 86.1851954 21.7714286 51.3769725 30.48 37.2903525 38.1 29.2882626 44.6314286 24.2572419 50.6185714 20.6666257 55.5171429 17.8557231 61.5042857 15.7521654 66.4028571 14.010543 71.3014286 12.5757127 75.6557143 11.3896861 81.0985714 10.3675128 84.9085714 9.4905422 89.2628571 8.71062322 94.1614286 8.02863132 97.9714286 7.43177311 101.781429 6.88730018 106.135714 6.38857082 109.401429 5.96262061 113.755714 5.54657305 117.565714 5.17890279 121.375714 4.84649854 125.73 4.51614612 128.451429 4.22362596 132.805714 3.95896745 142.058571 3.36579785 151.855714 2.86377793 160.564286 2.4262705 170.905714 2.04879901 179.614286 1.70911536 188.322857 1.41429123 196.487143 1.16367245 206.284286 0.92284446 214.992857 0.71389106 Distance (mm) Pressure (Kbar) Time (usec) Pentex-2 Distance (mm) Pressure (Kbar) Time (usec) Pentex-3 Distance (mm) Pressure (Kbar) Time (usec) Pentex-4 Distance (mm) Pressure (Kbar) Time (usec) Pentex-5 Distance (mm) Pressure (Kbar) (mm) 0 11.6417063 Average Distance Pressure (Kbar) 220 85.966299

21.3065275 51.0333294 29.6435275 37.0753155 37.0091301 29.4021834 43.8688964 24.2698584 50.2152567 20.5577433 55.6823641 17.8405101 61.1928524 15.7363618 66.5942036 13.9962569 71.0663522 12.5716335 75.9633331 11.3602435 80.7505381 10.3459413 85.5386618 9.46742633 89.9043254 8.70081203 93.8301762 8.01061948 98.0563029 7.41133391 102.006183 6.86317313 106.544994 6.37397782 110.362 5.93328022 114.178994 5.52630302 118.200107 5.15232555 121.90158 4.82022475 126.323964 4.50493814 129.807723 4.21549836 133.476424 3.9454809 142.951025 3.34934292 151.794595 2.84707456 160.852226 2.41256521 169.795498 2.03574086

103.34625 5.21120698 106.68 4.87092225 110.49 4.55027387 114.3 4.26489869 119.0625 3.98241724 122.8725 3.73805495 126.20625 3.5024563 135.255 2.98144598 144.78 2.54308159 153.82875 2.15898839 163.35375 1.82712517 171.92625 1.53547818 179.54625 1.27189872 183.8325 1.12431087

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Measurement of Vertical Pressure Generated from Shaped Charge Explosive

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