US2513531A - Safety sheathed blasting explosive cartridge - Google Patents

Safety sheathed blasting explosive cartridge Download PDF

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Publication number
US2513531A
US2513531A US617695A US61769545A US2513531A US 2513531 A US2513531 A US 2513531A US 617695 A US617695 A US 617695A US 61769545 A US61769545 A US 61769545A US 2513531 A US2513531 A US 2513531A
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US
United States
Prior art keywords
safety
sheathed
explosive
cartridge
explosive cartridge
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US617695A
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English (en)
Inventor
Taylor James
Phillips Alec Harold
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Imperial Chemical Industries Ltd
Original Assignee
Imperial Chemical Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Imperial Chemical Industries Ltd filed Critical Imperial Chemical Industries Ltd
Application granted granted Critical
Publication of US2513531A publication Critical patent/US2513531A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • F42B3/28—Cartridge cases characterised by the material used, e.g. coatings
    • C—CHEMISTRY; METALLURGY
    • C06—EXPLOSIVES; MATCHES
    • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
    • C06B45/00—Compositions or products which are defined by structure or arrangement of component of product
    • C06B45/12—Compositions or products which are defined by structure or arrangement of component of product having contiguous layers or zones
    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F42—AMMUNITION; BLASTING
    • F42D—BLASTING
    • F42D5/00—Safety arrangements

Definitions

  • the present invention relates to the provision of new or improved safety sheathed blasting explosive cartridges by which we mean a cartridge of a detonating explosive, made from a composition including a suitable proportion of ingredients adapted to minimise its capacity for igniting flredamp air mixtures or coal dust air mixtures when it detonates, is further provided along its cylindrical surface with an external safety sheath that also comprises flame quenching or cooling ingredients. More particularly the invention has reference to the composition of the safety sheaths in such cartridges, and has for an object to provide safety sheathed blastin cartridges that can be more advantageously manufactured or are superior in service to the hitherto known cartridges of the kind described.
  • the explosive composition customarily includes ammonium nitrate as one of its power producing ingredients, and one or more. compounds capable of vap'orisation, fusion, or thermal decomposition with absorption of heat as a flame quenching or coolin ingredient, and the safety sheath also comprises one or more compounds of the latter description.
  • the explosive cartridge proper it is also the practice for the explosive cartridge proper to be provided with aewaterproofed paper wrapper and for this portion of the sheathed cartridge to comply with the oflicial gallery tests for Permited Explosives.
  • Sheathing materials consisting essentially of various more or less insoluble metal carbonates have been tried with varying results.
  • sodium bicarbonate is the most effective and is the compound generally employed in practice in this country, notwithstanding the fact that it is slightly soluble in water and must .be carefully separated by a waterproof wrapping from the explosive cartridge, since it would otherwise react with the ammonium salt present in the explosive, to produce ammonium bicarbonate which gives rise to loss of ammonia and carbon dioxide.
  • the safety z sheath of a safety sheathed blasting explosive cartridge of the kind described comprises a mixture of one molar part of a metal carbonate not freely soluble in water and 0.33 to 2.0 molar parts of a dry hydrated form of alumina.
  • metal carbonate not freely soluble in water there may be employed for instance sodium bicarbonate. or a metal carbonate substantially insoluble in water; and in the latter case naturally occurring forms either hydrated or anhydrous, are frequently available; thus com minuted limestone, chalk, calcareous shell, dolomite, or magnesite, may be used.
  • the metal'carbonate should not .be more soluble in water than sodium bicarbonate.
  • the hydrated alumina and the metallic carbonate are advantageously both used in a fine state of division. If desired, other flame quenchin or cooling ingredients may be added to the mixture in minor proportions.
  • Figure 1 illustrates a shell having the explosive charge I enclosed by a paramned paper wrapper 2, a second paper wrapper 4 completely surrounding the wrapped charge, and the annular space 8 between the two wrappers filled with the powder mixture of the invention.
  • Figure 2 illustrates a rigid cylindrical sheath 5 formed by binding the powder mixture of .the invention with a binder such as platser of Paris, theexplosive charge I being then loaded into the cylinder.
  • Figure 3 illustrates an explosive charge I wrapped with a flexible sheet 6 made by incorporating a flexible binder with the powder mixture of hydrated alumina and metallic carbonate.
  • British Specification No. 416,586 discloses inter alia a flexible safety sheathing material for blasting explosives comprising in sheet form a uniform mixture of a fibrous bonding material and a preponderating proportion of a cooling salt or mixtures of cooling salts.
  • British Specification No. 424,784 discloses inter alia a method of forming materials suitable for use as cooling sheaths for safety blasting explosives wherein one or more cooling salts are mixed into a paste with an aqueous solution of a suitable organic binding agent such as gelatine and a hydroscopic polyhydric alcohol such as glycerine, the paste formed into any desired shape and dried.
  • a suitable organic binding agent such as gelatine
  • a hydroscopic polyhydric alcohol such as glycerine
  • Example Waxed paper covered cartridges of overall diameter 1%" containing explosive Polar Dynobel No. 2 are held centrally in a paper shell of 1 diameter closed 'in at one end.
  • a mixture containing 61 per cent of commercial trihydrate of alumina of which 99 per cent passes a 100 mesh and 90 per cent passes a 150 mesh British Standard Sieve, and 39 per cent of ground chalk, of which the whole passes a 150 mesh British Standard Sieve is poured into the annulus between the waxed paper cartridge and the outer paper shell.
  • the mixture is consolidated by tapping and the filling and tapping operations are repeated until the whole length of the cartridge is embedded in the mixture, care being taken to prevent accumulation of the mixture on the ends of the cartridge.
  • the weight of the flame quenching mixture amounts to 45 per cent of the weight of the explosive.
  • a safety sheathed blasting explosive cartridge wherein the safety sheath comprises a mixture of one molar part of a metal carbonate not freely soluble in water and 0.33 to 2.0 molar parts of a dry hydrated form of alumina.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Organic Chemistry (AREA)
  • Drilling And Exploitation, And Mining Machines And Methods (AREA)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
US617695A 1944-11-15 1945-09-20 Safety sheathed blasting explosive cartridge Expired - Lifetime US2513531A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB22537/44A GB585848A (en) 1944-11-15 1944-11-15 Improvements in or relating to safety sheathed blasting explosive cartridges and their manufacture

Publications (1)

Publication Number Publication Date
US2513531A true US2513531A (en) 1950-07-04

Family

ID=10181000

Family Applications (1)

Application Number Title Priority Date Filing Date
US617695A Expired - Lifetime US2513531A (en) 1944-11-15 1945-09-20 Safety sheathed blasting explosive cartridge

Country Status (7)

Country Link
US (1) US2513531A (is")
BE (1) BE461166A (is")
DE (1) DE840222C (is")
FR (1) FR916789A (is")
GB (1) GB585848A (is")
LU (1) LU27796A1 (is")
NL (1) NL67304C (is")

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3200743A (en) * 1963-10-24 1965-08-17 Trojan Powder Co Waterproof package for explosives
US3356546A (en) * 1963-12-30 1967-12-05 Ici Ltd Safety blasting composition with a metal formate as a fuel
US3648614A (en) * 1969-03-18 1972-03-14 Dynamit Nobel Ag Method for increasing the safety against firedamp ignitions during blasting in underground mining and blasting elements used for said purpose

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1225414A (en) * 1915-02-06 1917-05-08 Thomas John Ireland Craig Fireproofing of fabrics and other articles.
GB424784A (en) * 1933-08-30 1935-02-28 Russel Charrosin Payn Improvements in or relating to blasting cartridges
GB432850A (en) * 1933-01-24 1935-08-02 Arendonck Sa D Improvements in or relating to safety blasting cartridges
US2075969A (en) * 1933-07-24 1937-04-06 Ici Ltd Blasting explosive cartridge and borehole charge
GB543314A (en) * 1940-07-16 1942-02-19 Ian Alexander Forbes Improvements in or relating to safety sheathed blasting cartridges
US2413516A (en) * 1944-04-20 1946-12-31 Atlas Powder Co Sheathing material

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1225414A (en) * 1915-02-06 1917-05-08 Thomas John Ireland Craig Fireproofing of fabrics and other articles.
GB432850A (en) * 1933-01-24 1935-08-02 Arendonck Sa D Improvements in or relating to safety blasting cartridges
US2075969A (en) * 1933-07-24 1937-04-06 Ici Ltd Blasting explosive cartridge and borehole charge
GB424784A (en) * 1933-08-30 1935-02-28 Russel Charrosin Payn Improvements in or relating to blasting cartridges
GB543314A (en) * 1940-07-16 1942-02-19 Ian Alexander Forbes Improvements in or relating to safety sheathed blasting cartridges
US2413516A (en) * 1944-04-20 1946-12-31 Atlas Powder Co Sheathing material

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3200743A (en) * 1963-10-24 1965-08-17 Trojan Powder Co Waterproof package for explosives
US3356546A (en) * 1963-12-30 1967-12-05 Ici Ltd Safety blasting composition with a metal formate as a fuel
US3648614A (en) * 1969-03-18 1972-03-14 Dynamit Nobel Ag Method for increasing the safety against firedamp ignitions during blasting in underground mining and blasting elements used for said purpose

Also Published As

Publication number Publication date
DE840222C (de) 1952-05-29
GB585848A (en) 1947-02-26
NL67304C (is") 1950-09-15
FR916789A (fr) 1946-12-16
LU27796A1 (is")
BE461166A (is") 1946-05-07

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