CUMULATIVE CHARGE Russian patent published in 2019 - IPC F42B1/02 F42B1/28 

FIELD: blasting operations.

SUBSTANCE: invention relates to blasting. Cumulative charge can be used for perforation of oil and gas wells, explosive drilling of holes, destruction of oversized rocks, nailing metal sheets in industry and in construction. Charge includes a body, an initiator, an initiating charge and the main charge of an explosive with a cumulative notch and metal lining. Initiating charge is made in the form of a thin disk of a high blasting and highly sensitive explosive with an initiator in the center, the diameter of which is less than the critical diameter of detonation of the explosive of the main charge. There is a gasket made of a thin inert material between the main and initiating charges. Cumulative recess is made in the form of an open cylindrical cavity with a bottom convex toward the body of the main explosive charge in the form of a spherical segment with a deflection x along the charge axis within x=(0.1÷0.2)d and the height h of the cylindrical part of the notch h=(0.5÷1.0)d, where d is the diameter of the cylindrical part of the recess, the lining is made in the form of a thin-walled glass, which repeats the shape of the cumulative recess, the thickness of the lining is selected within (0.02÷0.10)d, diameter d of the cylindrical part of the recess is chosen the way the condition (D-d)/2>δ_cr. is fulfilled, where D is the diameter of the checkers of the main explosive charge, δ_cr – critical thickness of the detonation of the explosive of the main charge. Cylindrical part of the lining and the bottom are made either as a single piece, or composite and made of the same material or different.

EFFECT: increase in charge efficiency is achieved, primarily when perforating pipes by increasing the entrance diameter of the hole created by the cumulative jet.

1 cl, 1 dwg