US2256298A - Blasting device - Google Patents

Blasting device Download PDF

Info

Publication number
US2256298A
US2256298A US171391A US17139137A US2256298A US 2256298 A US2256298 A US 2256298A US 171391 A US171391 A US 171391A US 17139137 A US17139137 A US 17139137A US 2256298 A US2256298 A US 2256298A
Authority
US
United States
Prior art keywords
charge
pressure
tube
container
blasting
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
US171391A
Other languages
English (en)
Inventor
Taylor James
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 US2256298A publication Critical patent/US2256298A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • F42B3/04—Blasting cartridges, i.e. case and explosive for producing gas under pressure
    • F42B3/06—Blasting cartridges, i.e. case and explosive for producing gas under pressure with re-utilisable case
    • 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
    • F42B3/04—Blasting cartridges, i.e. case and explosive for producing gas under pressure

Definitions

  • This invention relates to blasting devices, par- Vticularly to those of the kind comprising a pres" sure-resistance reutilisable container, a charge of a solid material capable of undergoing a non- Vdetonatingv gas-evolving decomposition when locallyl initiated, ⁇ and'means for locally initiating the decomposition of the said charge.
  • Blasting devices of this kind have been proposed in which the container is charged at atmospheric pressure with a solid material of the kinddescribedvand is tted with avvalve or rupturable disc seal of high tensile strength material adapted to release the products of decomposition ofthe charge when the internal pressure has attained a" predetermined and considerable value sufficient to produce a blasting leffect when the device has been suitably located in a borehole.
  • Blasting devices of this latter kind rhave beenvr ⁇ .compositions is that their rates of exothermic decomposition, and hence their rates of development of gas pressure ywhen confined, do notv become great enough to produce a blasting efl fect until the decomposition is taking place under an already considerable pressure.
  • the considerable pressure mentioned above is built up by the gas evolved during the relatively slow decomposition of the charge imi mediately after its initiation at substantially norprolonged time static pressures up to the venting pressure.
  • This invention has as an object to provide a blasting device which does not require any screwed unions or detachable venting cap.
  • the support alone must be vcapable of withstanding an internal pressure of square inch.
  • the assembly can withstand pressures exceeding 30tons per square inch.
  • theicylindrical steel tube l is depicted as closed at one end. Adjacent to said closed end is a charge 2 of sodium nitrite l Embedded in said Y and ammonium chloride. charge is an electric igniter 3, the leadsv 4 of which pass downward and out through ⁇ the otherk end of said steel tube. Belowl the aforesaid charge 2 is a column of sand 5 supported by a plaster of Paris plug l retained inplace by means Aquired in each case to dislodge the assembly from the tube is given in the following table. The pressure required to dislodge the plaster of Paris plug alone was approximately-V2 ton per square inch.
  • Heght of Breakdown sand pressure column Tana per Inches square inch 1 0. 53 Z 0. 87 3 4. 07 3% 1l. 7 4 14Y 5
  • the usual'venting pressure of a 11/4" internal diameter blasting device of the kind described is 12 tons per square inch.
  • a blasting device comprises a pressure-resistant reutilisable container provided with a seal adapted to yield under an internal pressure substantially higher than atmospheric pressure, but considerably less than the pressure at which the device is intended to vent; a charge of a solid material capable of undergoing a non-detonating gas-producing exothermic decomposition after being locally initiated; means for local initiation of the charge; and a quantity of a granular or like substance having the property of packing under pressure, completely lling the free space between the charge and the seal, and in amount such that the device vents at a pressure suiicient to exert a blasting effect, but insuilicient to cause any deformation or other damage to the container.
  • Example 1 A cylindrical high-tensile steel tube, 11A; inches internal diameter, 1% inches external diameter, 20 inches long and closed at one end, is charged with 200 gm.
  • Example 2 A tube 29 inches long is charged with 300 gms. of a mixture as in Example 1.
  • the tamping consists of 12 inches of dry sand and a 2 inch Aplaster 0I Paris plug.
  • the means of initiation is a safety igniter of the type described in copending application Serial No. 758,317, led January 19, 1934, situated at the base of the tube. When initiated, the charge vents at a pressure of 16 tons per square inch.
  • a type of pressure-resistant container suitable for use according to the invention is a plain cylindrical steel tube closed at one end and if desired otherwise free from constructions, screwed fittings, or any other device likely to ,prevent free egress of the contents of the tube. Tubes open at both ends, and having the charge placed more or less evenly between two columns of granular packing material and two sealing plugs, may also be used: but the single-open-.end tube is preferred.
  • Another suitable type of container is a cylindrical steel tube hemispherically closed at both ends and provided with lateral venting apertures near one end.
  • the blast does not produce such a reaction tending to cause the tube to be moved in an axial direction as may ,happen when a simple open-ended tube is used.
  • I may use electrically-fired powder fuzes or detonators, or safety igniters.
  • Thepacking material used is preferably sand, or a similar material, the essential property being that it must pack" under the application of rapa plug of plaster of Paris, castinto place; but an oversize wooden or like plug driven into the mouth of the tube will a1so serve, although its resistance is more diicult torgauge.
  • seals cast into place I prefer to use sealing materials that expand on solidication, of which'. ⁇
  • plaster of- Paris is the most convenient.
  • the seal may be, if desired, formed afterthe device has been loaded in the borehole, for example by soaking the granular tamping at the mouth of the tube With Water and tamping the borehole next to the tube with solid carbon dioxide so that ⁇ a plug of ice is formed.
  • This invention is useful in the art as it provides new and 'effective blasting devices which are easy and economical to make.
  • Certain blasting devices constructed according to the invention are safe foruse in ery and gassy mines, and may even be vassembled, with ⁇ safety at the working face.
  • devices of the foregoing type vmay and provided with an initiating device of thev twype described in co-pending application Serial
  • an initiating device of thev twype described in co-pending application Serial
  • a non-detonating gas-generating blasting device comprising a non-destructible re-usable pressure-resistant container, a charge of nondetonating gas-producing material disposed in said container, igniting means disposed adjacent to said charge, venting means confining said charge in said container comprising a column of inert granular vmaterial and a cast plug of material having the property of expansion on solidication disposed in the end'oi said container and supporting said column of inert granular material.
  • a non-detonating gas-generating blasting device comprising a non-destructible re-usable pressure-resistant container, a charge of nondetonating gas-producing Ymaterial disposed.- in
  • venting means confining said charge in said container comprising a column of inert granular material and a plug of plasterv of Paris cast into place in the venting end of said container supporting said column of inert granular material.
  • a non-detonating gas-generating blasting device comprising a non-destructible re-usable pressure-resistant' container, a charge of nondetonating gas-producing material disposed in said container, igniting means disposed adjacent' to said charge, venting means confining said charge in said container comprising a column of sand and a plug member disposed in the end of said container suuporting said sand.
  • a non-detonating gas-generating blasting device comprising a re-usable*pressure-resistant container consisting of a cylindrical steel tube closed at one end, a charge of non-detonating gas-producing material disposed Within said tube adjacent to the closed end thereof, an igniter embodied in said charge, a column ofsandfdisposed in said tube between the locus of said charge and the opened end of said tube, keying means in the mouth of said tube, and a plug of plaster of Paris cast into place closing saidmouth and co-operating with said keying means.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Sealing Material Composition (AREA)
  • Filling Or Discharging Of Gas Storage Vessels (AREA)
  • Portable Nailing Machines And Staplers (AREA)
US171391A 1936-10-29 1937-10-27 Blasting device Expired - Lifetime US2256298A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB29474/36A GB484098A (en) 1936-10-29 1936-10-29 Improvements in or relating to blasting devices

Publications (1)

Publication Number Publication Date
US2256298A true US2256298A (en) 1941-09-16

Family

ID=10292129

Family Applications (1)

Application Number Title Priority Date Filing Date
US171391A Expired - Lifetime US2256298A (en) 1936-10-29 1937-10-27 Blasting device

Country Status (3)

Country Link
US (1) US2256298A (de)
DE (1) DE686305C (de)
GB (1) GB484098A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080047455A1 (en) * 2004-01-26 2008-02-28 Edward Walenty Tota Rock Breaking Cartridge and Use Thereof

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080047455A1 (en) * 2004-01-26 2008-02-28 Edward Walenty Tota Rock Breaking Cartridge and Use Thereof

Also Published As

Publication number Publication date
DE686305C (de) 1940-01-06
GB484098A (en) 1938-04-29

Similar Documents

Publication Publication Date Title
US3064572A (en) Method of and means for providing a charge of water sensitive explosive in a blast hole
US2759418A (en) Frozen nitrogen tetroxide-hydrocarbon explosives
US2256298A (en) Blasting device
US2704515A (en) Method of loading for liquid oxygen explosives
CN108917500B (zh) 一种铅芯式燃爆元件及由该燃爆元件组成的基础雷管
US2916995A (en) Tamping plug
US3961579A (en) Destructive devices
US2247169A (en) Blasting shell for surface blasting
NO870050L (no) Fremgangsmaate for lading av stroembart sprengstoff i oppad forloepende borehull.
US3713393A (en) Igniter mechanism for solid propellants under high fluid head
US2207191A (en) Apparatus for blasting coal
US2736261A (en) Blasting means
US2075969A (en) Blasting explosive cartridge and borehole charge
US2876700A (en) Blasting plug
JPS58218590A (ja) 多くの装薬による抗内爆発性ガスに安全な発破によりコントロ−ル不可能な坑内空間の材料を採掘する方法及び装置
CN1170868A (zh) 深孔装药爆破的轴向传爆方法及传爆筒和装药炮棍
US2732800A (en) coursen
US3013333A (en) Restoration process
US2038772A (en) Blasting charge
CA2621259C (en) Method of breaking brittle solids
US2083706A (en) Blasting apparatus
US3148580A (en) Method and apparatus for charging boreholes
US2953448A (en) Compositions for safety heating elements
US1569226A (en) Mechanical pressure device
RU2133942C1 (ru) Способ заряжания скважин