WO2016011463A1

WO2016011463A1 - An initiator

Info

Publication number: WO2016011463A1
Application number: PCT/ZA2015/000047
Authority: WO
Inventors: Andrè VAN DYK
Original assignee: Van Dyk Andrè
Priority date: 2014-07-02
Filing date: 2015-07-02
Publication date: 2016-01-21

Abstract

The invention provides a stable initiator for initiating explosives. The initiator includes a pair of spaced electrodes (4, 5) or an electrically conductive material and an ionic plasma generator (2) in contact with each of the pair of electrodes.

Description

Title: An Initiator

Technical field of the invention

This invention relates to an initiator for initiating explosives.

Background to the invention The inventor is aware of the use of initiators or igniters for igniting explosive materials such as in detonators or blasting caps. Typically these detonators are electrically controlled and are known as electro-pyrotechnic initiators. These initiators use an electrically heated bridge wire. However, these initiators or devices using these initiators can be unstable and can ignite by means of static electric discharge, electromagnetic induction or intense radio waves.

It is an object of the invention to provide a more stable initiator than that of known electro-pyrotechnic initiators.

General description of the invention

According to the invention there is provided an initiator, which includes:

a pair of spaced electrodes of an electrically conductive material; and an ionic plasma generator in contact with each of the pair of electrodes.

The plasma generator may include a non-conductive base covered with a layer or film of electrically resistive material, which when heated will form a cloud of plasma. The electrically resistive material may be selected from nickel chrome alloy or ruthenium(IV)oxide and similar materials.

The distance between the electrodes and the mass of the plasma forming material is selected such that the plasma cloud makes contact with both electrodes to allow flow of current between the electrodes It will be appreciated that an electrical signal can then be formed and that initiation can be synchronised or timed. In addition, ions from the plasma cloud will deposit onto an explosive compound or pyrotechnic compound with sufficient thermal energy to ignite the compound.

The electrodes should have good conductance such as copper.

The electrodes may be arranged as parallel strips on a fiat surface of a non-conductive plate such as ceramic, plastic or other non-conductive polymeric plate. The plasma forming material may also be in the form of a strip transverse to and in contact with the electrodes.

Depending on the resistance of the plasma generator, typical voltages will range from 100 to 400 volts.

In another embodiment of the invention, the electrodes may be in the form of pins (electrodes) which extend parallel to each other away from a non- conductive substrate with the mass of plasma forming material in contact with the electrodes near the base of the electrodes. It will be appreciated that, when formed, the cloud will envelope the pins to allow flow of electric current between the pins (electrodes).

It is to be appreciated that the initiator, in accordance with the invention, will be stable with regards to heat, static discharges, electromagnetic discharges and intense radio waves.

The invention also extends to a blasting cap, which includes explosive material and an initiator as described above. An example of an explosive compound is lead styphnate.

Detailed description of the invention

The invention is now described by way of further example with reference to the accompanying drawings. In the drawings;

Figure 1 shows a simplified diagram of one configuration of a non explosive plasma igniter;

Figure 2 shows a simplified diagram of a similar configuration shown in Figure 1 of a non explosive plasma igniter; and

Figure 3 shows a simplified diagram of another configuration of a non explosive plasma igniter.

Figure 1 shows a non explosive plasma igniter configuration in the X, or horizontal, orientation mounted on a non-conductive substrate or base 3. The copper cathode is indicated by 4 and the copper anode by 5. The anode and cathode is connected, in use to conductors 1 of an electronic initiator system. The ion plasma generator of ruthenium(IV)oxide is indicated by 2. The ion plasma generator 2 can be in any position on the two conductive strips that is the cathode 4 and anode 5, at one end in this configuration, see Figure 2. in Figure 2, the ionic plasma cloud is shown by 6.

Typical Specifications:

X= 10mm

Z= 5mm

2= 0.5-3.0mm

a1= 1mm

a2= 1mm

F= 0.2 - 50 ohm

d= 1 - 3mm

Figure 3 shows a non explosive plasma igniter configuration in the Y, or vertical, orientation mounted on a non-conductive substrate or base 3. The electrodes 4 and 5 are in the form of copper pins which extend parallel to each other away from a non-conductive substrate 3 with the mass of plasma forming material 2 in contact with the electrodes near the base of the pins.

When a high electric current is flowing through the conductors (1) the ion plasma generator (2) will explode and create an ionic plasma cloud (6) that is conductive and will allow current flow through the cloud between the Anode (5) and Cathode (4). The anode (5) and cathode (4) with the ionic plasma generator (2) is mounted on a nonconductive substrate. The mounting of the Cathode (4) and Anode (5) can be in the X or Y orientation depending on the application.

Advantages:

1. The igniter will form a conductive unit that will allow electric current to flow through even after the plasma generator explodes to form a ionic plasma cloud.

2. This will allow a series connection of igniters with accurate ignition of all the igniters.

3. Fast ignition capability

4. Static electricity safe igniter

5. Non explosive igniter with superior safety

6. Non-toxic igniter materials

7. High accuracy igniters

It shall be understood that the examples are provided for illustrating the invention further and to assist a person skilled in the art with understanding the invention and are not meant to be construed as unduly limiting the reasonable scope of the invention.

Claims

CLAIMS 1- An initiator, which includes:

2. An initiator as claimed in Claim 1, wherein the plasma generator includes a non-conductive base covered with a layer or film of electrically resistive material, which when heated forms a cloud of plasma.

3. An initiator as claimed in Claim 2, wherein the electrically resistive material is selected from nickel chrome alloy and ruthenium(IV)oxide.

4. An initiator as claimed in any one of claims 1 to 3 wherein the distance between the electrodes and the mass of the plasma forming material is selected such that a formed plasma cloud makes contact with both electrodes to allow flow of current between the electrodes.

5. An initiator as claimed in any one of claims 1 to 4 wherein the electrodes are arranged as parallel strips on a flat surface of a non-conductive plate or pins extending from of a non-conductive plate, which non-conductive material is selected from ceramic and polymeric material and wherein the plasma forming material is in the form of a strip transverse to and in contact with the electrodes.

6. A blasting cap, which includes explosive material and an initiator as claimed in any one of claims 1 to 5.

7. An initiator, substantially as described herein with reference to the accompanying drawings.

8. A blasting cap, substantially as described herein with reference to the accompanying drawings.