Downline wire
AssigneeDetnet South Africa (Pty) Ltd
InventorPhillip OLWAGE
Life of this patent
Estimating the term…
Abstract
A downline wire for connecting a location on surface to at least one detonator in a blast hole, the downline wire including at least two flexible electrical conductors, a respective flexible layer of an insulating material which encases each conductor, and a flexible sheath in which the insulated conductors are embedded, wherein each conductor comprises a steel core which is clad with copper, the insulating material is selected from a filled flexible polyvinylchloride (PVC) composition and a polyester elastomer, and the sheath is made from a medium or high density polyethylene compound which includes carbon black.
Claims46
A downline wire for connecting a location on surface to at least one detonator in a blast hole, the downline wire including at least two flexible electrical conductors, a respective flexible layer of an insulating material which encases each conductor, and a flexible sheath in which the insulated conductors are embedded, wherein each conductor comprises a steel core which is clad with copper, the insulating material is selected from a filled flexible polyvinylchloride (PVC) composition and a polyester elastomer, and the sheath is made from a medium or high density polyethylene compound.
A detonation system comprising:
- a detonator to provide a charge to ignite an explosive;
- and
- a downline wire to connect the detonator to a surface location, the downline wire comprising:
- two conductors;
- a flexible thermoplastic insulator encasing the two conductors;
- and
- a polyethylene sheath encasing the flexible thermoplastic insulator and the two conductors.
A method for loading a blast hole comprising:
- connecting a booster and a detonator to a downline wire, the downline wire comprising:
- two conductors with a tensile strength from 38 kg/mm2 to 58 kg/mm2, and an elongation at breakage from 18% to 30%,
- a flexible thermoplastic insulator encasing the two conductors, and
- a sheath encasing the flexible layer and the two conductors, the sheath comprising a polyethylene compound;
- placing the booster and the detonator in a blast hole;
- and
- filling the blast hole with an explosive material comprising an emulsion, a mixture, or both where the detonator experiences a dynamic force that causes the downline wire to elongate while the blast hole is being filled, and when a static force is exerted by the explosive material on the downline wire.
A method of manufacturing a downline wire for an explosive detonation system, the method comprising:
- providing two copper-clad steel cores;
- encasing each of the two copper-clad steel cores in a flexible thermoplastic insulator to form separate insulated conductors;
- and
- encasing both of the separate insulated conductors in a polyethylene sheath.
A detonation system to withstand forces from loading a blast hole, the detonation system comprising:
- a detonator to provide a charge to ignite an explosive;
- and
- a downline wire to connect the detonator to a surface location, the downline wire comprising:
- two conductors;
- two insulating covers encasing the two conductors;
- and
- a flattened-oval sheath encasing the insulating covers and the two conductors,
- wherein the distance between a center of each conductor is more than half of a cross-sectional length of the sheath.
A method of loading a blasthole, comprising:
- connecting a booster and a detonator to a downline wire;
- placing the booster, the detonator, and the downline wire in a blasthole;
- and
- controlling delivery of an explosive material comprising an emulsion, mixture, or both into the blast hole so that a force on the booster, detonator, and the downline wire is less than 350 N.
Dependencies are inferred from the claim text.