Pyrotechnic compositions for severing conduits

• US 4,424,086 A
• Filed: 07/06/1982
• Issued: 01/03/1984
• Est. Priority Date: 10/03/1980
• Status: Expired due to Fees

• Current Assignee: Halliburton Company
• Original Assignee: Jet Research Center Incorporated
• Inventors: Christopher, Glenn B.
• Primary Examiner(s): Miller, Edward A.
• Application Number:
  US06/395,215
• Time in Patent Office: 546 Days
• Field of Search: 149/19.3, 149/37, 149/2, 149/40, 102/364, 102/286
• US Class Current: 149/19.3
• CPC Class Codes: C06B 33/02 with an organic non-explosive or an organic non-thermic component
• CPC Class Codes: E21B 29/02 by explosives or by thermal or chemical means freeing stuck objects by explosives E21B31/002
• CPC Class Codes: F42D 3/00 Particular applications of blasting techniques explosive welding B23K20/08; explosive bolts or actuators F42B3/006; explosive valves F16K13/06; cutting devices actuated by explosion B23D15/145; pyrotechnical actuators F15B15/19; switching devices actuated by explosion H01H39/00

Abstract

A stacked load of gas-forming pyrotechnic fuel pellets comprising metal, metal oxide and PTFE in varying amounts for use in apparatus for severing conduits in high pressure environments.

Claims

1. A gas-forming pyrotechnic fuel composition load for use in apparatus for severing conduits in high pressure environments comprising a plurality of stacked fuel pellets of a mixture of (a) a metal selected from the group consisting of aluminum, magnesium, niobium, titanium and mixtures thereof, (b) a metal oxide selected from the group consisting of ferric oxide, ferrous oxide, ferrosoferric oxide, cupric oxide, chromium trioxide and mixtures thereof, and (c) a gas-forming component which vaporizes to form a gas when heated to the temperature at which said metal and said metal oxide react when ignited wherein alternate fuel pellets of said load have alternate amounts of said gas-forming component.

2. The fuel composition load of claim 1 wherein the first fuel pellet in the stacked load has less gas-forming component therein than the next adjacent fuel pellet.

3. The fuel composition load of claim 2 wherein said gas-forming component is polytetrafluoroethylene.

4. The fuel composition load of claim 3 wherein said metal is aluminum and said metal oxide is selected from the group consisting of ferric oxide, cupric oxide and mixtures thereof.

5. The fuel composition load of claim 4 wherein aluminum is present in said composition in an amount in the range of from about 8% to about 70% by weight of said composition.

6. The fuel composition load of claim 5 wherein said metal oxide is present in said composition in an amount in the range of from about 12% to about 80% by weight of said composition.

7. The composition load of claim 6 wherein said polytetrafluoroethylene is present in said composition in an amount in the range of from about 1% to about 60% by weight of said composition.

8. The fuel composition load of claim 2 wherein said first fuel pellet comprises aluminum present therein in an amount of about 25.5% by weight, a metal oxide selected from the group consisting of ferric oxide, cupric oxide and mixtures thereof present therein in an amount of about 59.5% by weight and polytetrafluoroethylene present therein in an amount of about 15% by weight.

9. The fuel composition load of claim 8 wherein said next adjacent fuel pellet comprises aluminum present therein in an amount of about 7.5% by weight, a metal oxide selected from the group consisting of ferric oxide, cupric oxide and mixtures thereof present therein in an amount of about 17.5% by weight and polytetrafluoroethylene present therein in an amount of about 75% by weight.

10. The fuel composition load of claim 9 wherein each of said fuel pellets is annular in shape and the central opening in said pellets is filled with powdered non-gas-forming pyrotechnic fuel composition.

11. The fuel composition load of claim 10 wherein said powdered non-gas-forming pyrotechnic fuel composition within the central openings of said fuel pellets comprises aluminum present in said composition in an amount of about 30% by weight and a metal oxide selected from the group consisting of ferric oxide, cupric oxide and mixtures thereof present in said composition in an amount of about 70% by weight.