WO2017208024A1 - Explosive booster - Google Patents
Explosive booster Download PDFInfo
- Publication number
- WO2017208024A1 WO2017208024A1 PCT/GB2017/051602 GB2017051602W WO2017208024A1 WO 2017208024 A1 WO2017208024 A1 WO 2017208024A1 GB 2017051602 W GB2017051602 W GB 2017051602W WO 2017208024 A1 WO2017208024 A1 WO 2017208024A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- cord
- housing
- explosive
- booster
- explosive material
- Prior art date
Links
- 239000002360 explosive Substances 0.000 title claims abstract description 101
- 239000000463 material Substances 0.000 claims abstract description 39
- 230000000977 initiatory effect Effects 0.000 claims abstract description 25
- 230000000717 retained effect Effects 0.000 claims abstract description 4
- 239000004033 plastic Substances 0.000 claims description 25
- 229920003023 plastic Polymers 0.000 claims description 25
- 238000005474 detonation Methods 0.000 claims description 17
- 229910052751 metal Inorganic materials 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 8
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- 239000004411 aluminium Substances 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 239000010949 copper Substances 0.000 claims description 3
- 230000001681 protective effect Effects 0.000 claims description 2
- TZRXHJWUDPFEEY-UHFFFAOYSA-N Pentaerythritol Tetranitrate Chemical group [O-][N+](=O)OCC(CO[N+]([O-])=O)(CO[N+]([O-])=O)CO[N+]([O-])=O TZRXHJWUDPFEEY-UHFFFAOYSA-N 0.000 description 9
- 239000000026 Pentaerythritol tetranitrate Substances 0.000 description 9
- 229960004321 pentaerithrityl tetranitrate Drugs 0.000 description 9
- 230000035939 shock Effects 0.000 description 8
- 238000005422 blasting Methods 0.000 description 5
- 239000003999 initiator Substances 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- XTFIVUDBNACUBN-UHFFFAOYSA-N 1,3,5-trinitro-1,3,5-triazinane Chemical compound [O-][N+](=O)N1CN([N+]([O-])=O)CN([N+]([O-])=O)C1 XTFIVUDBNACUBN-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 238000003491 array Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 239000000499 gel Substances 0.000 description 2
- 238000010137 moulding (plastic) Methods 0.000 description 2
- FZIONDGWZAKCEX-UHFFFAOYSA-N nitrogen triiodide Chemical compound IN(I)I FZIONDGWZAKCEX-UHFFFAOYSA-N 0.000 description 2
- 238000009527 percussion Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 230000003292 diminished effect Effects 0.000 description 1
- 230000003467 diminishing effect Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000005670 electromagnetic radiation Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 229920002457 flexible plastic Polymers 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- -1 nitrogen triiodide Chemical class 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000005060 rubber Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 238000004078 waterproofing Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42D—BLASTING
- F42D1/00—Blasting methods or apparatus, e.g. loading or tamping
- F42D1/04—Arrangements for ignition
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42D—BLASTING
- F42D1/00—Blasting methods or apparatus, e.g. loading or tamping
- F42D1/04—Arrangements for ignition
- F42D1/043—Connectors for detonating cords and ignition tubes, e.g. Nonel tubes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
- F42B3/00—Blasting cartridges, i.e. case and explosive
- F42B3/22—Elements for controlling or guiding the detonation wave, e.g. tubes
Definitions
- An explosive booster is a sensitive explosive charge that acts as a bridge between a (relatively weak) conventional detonator and a low-sensitivity (but typically high- energy) explosive such as TNT.
- the initiating detonator would not deliver sufficient energy to set off the low-sensitivity charge. However, it detonates the primary charge (the booster), which then delivers an explosive Shockwave that is sufficient to detonate the secondary, main, high-energy charge.
- Detonating cord consists of a train of finely powdered high explosive constituting the core of a cord in which it is wrapped by such materials as a strip of paper and two or more helically wound plastics threads or strip. This assembly is usually coated with water- proofing wax or a seamless flexible layer of water and abrasion-proof flexible plastics.
- the explosive most commonly used for this purpose is pentaerythritol tetranitrate (PETN) but cyclic- trimethylenetrinitramine (RDX) is sometimes used for the
- the explosive load usually ranges from approximately l .5g a metre to 200g a metre.
- Detonating cord most commonly employed in military usage contains 10 or I 2g a metre.
- One of the main applications of detonating cords with light or medium explosive loads is the transmission of a detonation wave from the point of initiation to a multiplicity of explosive main charges either in very rapid succession or simultaneously on the scale of the overall event.
- Detonation cord will initiate most commercial high explosives (dynamite, gelignite, sensitised gels, etc.) but will not initiate less sensitive blasting agents like ANFO on its own. 25 to 50 grain/foot (5.3 to 10.6 g/m) detonation cord has approximately the same initiating power as a #8 blasting cap in every 2 to 4 inches (5 to 10 cm) along its entire length. A small charge of PETN, TNT, or other explosive booster is normally required to bridge between the cord and a charge of insensitive blasting agent like ANFO or most water gels.
- a booster charge is more sensitive to initiation than the main charge and is of such shape and size as enables it to be abutted against the end of an elongate main charge or to be inserted in a cavity provided in the end, or at another convenient point, in the secondary charge.
- a primary explosive is an explosive that is extremely sensitive to stimuli such as impact, friction, heat, static electricity, or electromagnetic radiation. Some primary explosives are also known as contact explosives. A relatively small amount of energy is required for initiation. As a very general rule, primary explosives are considered to be those compounds that are more sensitive than PETN. As a practical measure, primary explosives are sufficiently sensitive that they can be reliably initiated with a blow from a hammer; however, PETN can also usually be initiated in this manner, so this is only a very broad guideline. Additionally, several compounds, such as nitrogen triiodide, are so sensitive that they cannot even be handled without detonating. Nitrogen triiodide is so sensitive that it can be reliably detonated by exposure to alpha radiation; it is the only explosive for which this is true.
- Primary explosives are often used in detonators or to trigger larger charges of less sensitive secondary explosives.
- Primary explosives are commonly used in blasting caps and percussion caps to translate a physical shock signal. In other situations, different signals such as electrical/physical shock, or, in the case of laser detonation systems, light, are used to initiate an action, i.e., an explosion.
- a small quantity, usually milligrams, is sufficient to initiate a larger charge of explosive that is usually safer to handle.
- a secondary explosive is less sensitive than a primary explosive and requires substantially more energy to be initiated. Because they are less sensitive, they are usable in a wider variety of applications and are safer to handle and store.
- Secondary explosives are used in larger quantities in an explosive train and are usually initiated by a smaller quantity of a primary explosive. Examples of secondary explosives include TNT and RDX.
- Tertiary explosives also called blasting agents, are so insensitive to shock that they cannot be reliably detonated by practical quantities of primary explosive, and instead require an intermediate explosive booster of secondary explosive. These are often used for safety and the typically lower costs of material and handling.
- the largest consumers are large-scale mining and construction operations.
- ANFO is an example of a tertiary explosive.
- the Slip on Booster (SOB) consists of a length of extruded tubular PETN-based plastic-bonded explosive with a slightly elastic consistency which, having an internal diameter of approximately 7mm, accommodates usual sizes of electric and plain detonators as well as detonating cord used in demolition operations. It is approximately 17mm in outside diameter. It can easily be cut to a requisite length [see Fig. I A, I B, 8A and 8B].
- SOB Slip on Booster
- the Detonating Cord Booster (DCB) consists of a conventional detonator tube which has a base charge of highly consolidated PETN with a succession of layers of PETN pressed upon it at progressively diminished pressures.
- a plastic clip is provided with an integral barrel which is crimped into the metal tube. The two jaws of the clip are such as to receive and grip a length of detonating cord inserted in a direction at right angles to the metal tube.
- the end of the barrel where it is attached to the clip is provided with s thin end wall. Initiation of the detonating cord shears the end wall and projects it along the barrel and towards the surface of the PETN which it strikes at a velocity high enough to cause detonation [see Fig. 2 and Fig. 9].
- booster is constituted by a bulky knot tied in the end of a length of detonating cord. This is commonly used for the initiation of a main charge of plastic explosive which can be squeezed into the interstices of the knot and moulded around it.
- a film of stretchable plastics such as is used more commonly for the containment and protection of foodstuffs may be advantageously stretched round the assembly and held in place by plastics insulating tape. Initiation of the main charge in this case is favoured by the amount of explosive contained in the detonating cord constituting the knot as well as the occurrence of multiple Shockwave collisions occurring within the compass of the know each of which constitutes a concentration of shock waves at various points in the mass of plastic explosive.
- the Detonating Cord Loop Initiator consists of a loop formed at the terminal end of a length of detonating cord by bending this end back on itself and securing it in this position, thereby defining a loop with a profile approximately in the shape of a teardrop.
- This elongate space is filled with plastic explosive. Constraining the detonating cord in a suitably proportioned loop can be achieved either by taping the ends together for a short distance immediately before the cusp of the loop or by inserting the loop into a cavity in, for example, a plastic moulding which constrains the loop and prevents expansion [see Fig.4 and Fig. I I ].
- the first mode results from immediate initiation of the returning tail of the cord by the advancing primary detonation front then progress with approximate symmetry along each limb. As these diverge and approach each other at the middle of the loop, the two shock waves travel through the plastic explosive between them and collide along the longitudinal mid-plane of the plastic explosive. Finally the two detonation waves collide at the approximate mid-point of the loop, thereby generating an enhanced shock in the plastic explosive. This is believed to be the most favourable initiation pattern.
- the present invention provides an explosive booster comprising a generally tubular elongate housing which provides confinement in order to cause initiation, at one end of the housing a length of detonating cord is inserted so as to extend into the housing, and the housing contains secondary explosive material, the end of the cord is retained in or by the housing so as to be adjacent (e.g. immediately adjacent; touching/in physical contact with) the explosive material or inserted therein, the interface between the cord end and the material is confined by the housing so that the explosive material can be initiated directly by the cord.
- the secondary explosive material may comprise plastic explosive.
- the cord may be crimped into the end of the housing.
- the detonating cord may extend into the housing beyond the crimp i.e. the interface between the explosive material of the detonating cord and the secondary material (main charge) is "downstream" of the crimped zone.
- the tube may be formed, for example, from aluminium or copper.
- the booster may further comprise a supporting sleeve for surrounding the cord within the housing in order to constrain it concentrically.
- the booster may further comprise a protective end cap.
- the booster may comprise a blind-ended tube (similar to that of a detonator), or a detonator tube with a hole drilled in it.
- the present invention also provides an explosive booster charge comprising a rigid tube which is open at both ends, at one end of the tube detonating cord is inserted and terminates with a cord end, the tube contains detonating cord insensitive explosive material, the cord end abuts against the explosive material and is held in position so that the interface between the cord end and the explosive material is confined by the tube whereby initiation of the material can be driven by the cord.
- the present invention also provides a system for conveying detonation from a length of detonating cord to a main charge without the need of an intermediate charge of primary explosive, comprising a housing which is open at both ends, at one end of the housing detonating cord is inserted and terminates with a cord end, the housing receives detonating cord insensitive explosive material, in use the cord end abuts against the explosive material and is held in position so that the interface between the cord end and the explosive material is confined by the housing whereby initiation of the material can be driven by the cord, the housing having an external configuration such as can fit into a tubular holder designed for receiving an retaining a conventional elongate detonator.
- the present invention may also include the use of a Plain Detonator Adaptor (PDA) crimped on the end of a tube with a short length of detcord itself going into the secondary (plastic) explosive.
- PDA Plain Detonator Adaptor
- the PDA (shown in Figure 7) replicates the shape of the Detonating Cord Booster (DCB) - see Fig. 2.
- the Plain Detonator Adaptor produced by the applicant, is an ingenious solution to the old problem of connecting multiple charges into a ring main reliably.
- a knot of detcord in the charge tied onto a ring main will work fine, but when using more precise charges, such as a shaped charge, that is a good way of messing up the performance of the charge.
- the best initiator of this type of charge is a detonator, but until now there have not been good ways of connecting everything together.
- the PDA is a small, plastic moulding that can be fitted and crimped into the end of a standard plain detonator.
- the PDA has a plastic U-shaped cradle designed to accept detonating cord which can be pushed into place anywhere on a line of detcord. The position of the charge can be adjusted but once engaged it cannot be removed from the ring main.
- the detcord When the detcord is initiated it punches out a small disc of plastic which is shot down the tube of the PDA straight into the primary composition of the detonator which is reliably initiated on impact.
- the invention consists most typically of an open ended length of metal tubing 10 of similar dimensions to those of an ordinary detonator. Aluminium or copper are the preferred metals.
- a length of detonating cord 15 is crimped into one end of the tube 10.
- the detonating cord 15 extends several millimetres along the inside of the tube beyond the crimp 20, the inserted end 17 of the cord 15 being cut transversely (i.e. a straight cut at approximately 90 degrees to the length of the cord) and care being taken that little or no explosive 18 spills from the cord.
- a suitable secondary explosive fills the remaining part of the tube; that is, between the severed end 17 of the detonating cord and the open end of the tube.
- Plastic explosive 25 is tamped incrementally into the remainder of the tube. If the booster is not to be used at once, then protection of the tube contends by means of a rubber, plastics or metal end-cap 27or foil is desirable [see Fig.5 and Fig. 12].
- the plastic explosive is replaced by a factory- filled with a suitably sensitive plastic bonded explosive. Either the manufacturer or the user then needs only to insert the initiating length of detonating cord so that it abuts against the plastic charge and to crimp it in place.
- Yet another form of the invention is of similar construction except that the detonating cord is also crimped into the tube as part of the manufacturing process. If a detonation cord is employed of which the diameter is significantly less than the inside diameter of the metal tube then a supporting sleeve 1 30 may surround that part of the detonating cord which is within the metal tube in order to constrain it concentrically within the tube and thus prevent such deformation as may cause displacement of some of its explosive content and partial obturation of the explosive path by collapse of the plastic and paper wall components of the cord [see Fig. 6].
- the invention contains no primary explosive so does not need to be stored and transported with detonators and other flame and percussion-sensitive devices but may reasonably be considered as to require storage and transportation limitations proper to secondary explosives.
- a multiplicity of charges may be assembled and fired using a single detonator attached to a single length of detonating cord or to an array of interconnected lengths of detonating cord of which the configuration causes an array of main charges to be initiated simultaneously, in rapid succession or in groups.
- the array need be is sensitised for initiation only when all the charges have been placed and interconnected.
- the charges may be assembled in closed ended tubes. 5. If factory filled, the base charges of the devices may consist of compressed powdered explosive, press either in a homogeneous column or in a series of increments which are pressed to a sequentially diminishing pressure, thereby combining relatively easy and reliable initiation leading to maximum pressure output at the distal end.
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Air Bags (AREA)
- Manufacturing Of Electrical Connectors (AREA)
- Toys (AREA)
Abstract
Description
Claims
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1819000.9A GB2565697A (en) | 2016-06-03 | 2017-06-05 | Explosive booster |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1609788.3A GB2555072B (en) | 2016-06-03 | 2016-06-03 | Explosive booster |
GB1609788.3 | 2016-06-03 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2017208024A1 true WO2017208024A1 (en) | 2017-12-07 |
Family
ID=56508073
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/GB2017/051602 WO2017208024A1 (en) | 2016-06-03 | 2017-06-05 | Explosive booster |
Country Status (2)
Country | Link |
---|---|
GB (2) | GB2555072B (en) |
WO (1) | WO2017208024A1 (en) |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2388310A (en) * | 1943-09-01 | 1945-11-06 | John S Curtiss | Blasting cap fuse protector |
EP0015067A1 (en) * | 1979-01-24 | 1980-09-03 | E.I. Du Pont De Nemours And Company | Field-connected explosive booster, booster-connector assembly and detonating cord assembly comprising such booster-connector assembly |
DE3010067A1 (en) * | 1980-03-15 | 1981-10-15 | Friedrich Wilhelm Dipl.-Kfm. 4600 Dortmund Sobbe | Fuse and detonator with pressure resistant watertight joint - made by lubricated sleeve between fuse and capsule |
GB2348944A (en) * | 1999-04-16 | 2000-10-18 | Schlumberger Holdings | Booster for use with detonating cords |
US6247410B1 (en) * | 1998-12-10 | 2001-06-19 | The United States Of America As Represented By The Secretary Of The Navy | High-output insensitive munition detonating cord |
US20040216632A1 (en) * | 2003-04-10 | 2004-11-04 | Finsterwald Mark A. | Detonating cord interrupt device and method for transporting an explosive device |
US20130291711A1 (en) * | 2012-05-03 | 2013-11-07 | Halliburton Energy Services, Inc. | Explosive Device Booster Assembly and Method of Use |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6846372B1 (en) * | 2003-03-31 | 2005-01-25 | The United States Of America As Represented By The Secretary Of The Navy | Reactively induced fragmentating explosives |
CN103644787B (en) * | 2013-12-04 | 2016-02-03 | 中国船舶重工集团公司第七〇五研究所 | A kind of primacord propagation of explosion energy amplifying device |
-
2016
- 2016-06-03 GB GB1609788.3A patent/GB2555072B/en active Active
-
2017
- 2017-06-05 WO PCT/GB2017/051602 patent/WO2017208024A1/en active Application Filing
- 2017-06-05 GB GB1819000.9A patent/GB2565697A/en not_active Withdrawn
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2388310A (en) * | 1943-09-01 | 1945-11-06 | John S Curtiss | Blasting cap fuse protector |
EP0015067A1 (en) * | 1979-01-24 | 1980-09-03 | E.I. Du Pont De Nemours And Company | Field-connected explosive booster, booster-connector assembly and detonating cord assembly comprising such booster-connector assembly |
DE3010067A1 (en) * | 1980-03-15 | 1981-10-15 | Friedrich Wilhelm Dipl.-Kfm. 4600 Dortmund Sobbe | Fuse and detonator with pressure resistant watertight joint - made by lubricated sleeve between fuse and capsule |
US6247410B1 (en) * | 1998-12-10 | 2001-06-19 | The United States Of America As Represented By The Secretary Of The Navy | High-output insensitive munition detonating cord |
GB2348944A (en) * | 1999-04-16 | 2000-10-18 | Schlumberger Holdings | Booster for use with detonating cords |
US20040216632A1 (en) * | 2003-04-10 | 2004-11-04 | Finsterwald Mark A. | Detonating cord interrupt device and method for transporting an explosive device |
US20130291711A1 (en) * | 2012-05-03 | 2013-11-07 | Halliburton Energy Services, Inc. | Explosive Device Booster Assembly and Method of Use |
Also Published As
Publication number | Publication date |
---|---|
GB2565697A (en) | 2019-02-20 |
GB201609788D0 (en) | 2016-07-20 |
GB201819000D0 (en) | 2019-01-09 |
GB2555072B (en) | 2022-01-19 |
GB2555072A (en) | 2018-04-25 |
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