RU110191U1 - DEVICE FOR DETERMINING THE EXPLOSIVE SUBSTANCE CHARGE DETONATION SPEED (OPTIONS) - Google Patents

Abstract

 1. A device for determining the detonation velocity of explosive charges in the shell, consisting of a detonation pulse conductor and a chronograph, characterized in that it additionally contains a connecting cable, as a chronograph - a digital single or multi-interval electronic time meter, as a detonation pulse conductor - waveguides of a non-electric explosive system of equal length introduced into the explosive charge perpendicular to its longitudinal axis at fixed distances from each other ; as sensors, electrical contact sensors operating on “closure” are used, placed inside the channels of the waveguides at their ends at a predetermined distance from each other and connected via an electric cable to a digital single or multi-interval electronic time meter, the start and stop of which is carried out by signals from the sensors, when the front of a shock wave passes through the waveguide, and the detonation velocity of the explosive charge is calculated based on the length of the base and the time interval electrocontact sensors, according to the formula:! ! where DBB is the detonation velocity of the explosive charge, m / s; ! LBB - the length of the explosive charge section (base) between the centers of the installation of waveguides, m; ! Δτ is the response time interval of two adjacent electrical contact sensors at the ends of the waveguides installed on the measuring base, s. ! 2. The device according to claim 1, characterized in that it comprises, as an electronic time meter, single-interval industrial electronic counting frequency meters. ! 3. The device according to claim 1, characterized

Description

The utility model relates to a measurement technique for determining the detonation velocity of explosives and can be used for blasting in industrial conditions and for research purposes.

The detonation velocity is one of the main characteristics of the explosive charge. Knowing its numerical value will allow you to control the energy of the explosion during rock explosions in various mining and geological conditions and to ensure high-quality crushing of the blasted rocks.

At present, devices have been developed for estimating the speed of detonation, based on the use of various types of chronographs, oscilloscopes, and photographic registers, which are used to measure short periods of time.

The registration of detonation velocities by photo-registers (optical devices) is based on a scan of light phenomena arising from their propagation. If the processes are not accompanied by their own luminescence, then the photo-register registers changes in the luminous flux from some extraneous light source caused by the process under study (1, 2).

A device is known for determining the detonation velocity of an explosive, based on the electromagnetic effect - registration of electromagnetic waves emitted during the propagation of a detonation wave along the explosive charge (3). The test charge is placed inside a hollow cylinder with one open end and is initiated using a detonator. When a detonation wave propagates along an explosive charge along the longitudinal axis of the cylinder, electromagnetic radiation is captured by two slits cut in the cylinder wall at a fixed distance from each other along the propagation of the detonation wave and treated with a dielectric. The signals induced on the walls of the slots are fed through the corresponding electric circuit to the inputs of the oscilloscope, on the screen of which these signals are displayed in the form of pulses of positive polarity; the distance between pulses at a selected sweep scale determines the time the detonation wave travels the distance between the slots in the cylinder. Knowing the distance between the slots (the value of the base) and the propagation time of the detonation wave through it, the detonation velocity is calculated. The disadvantage of this device is its complex design, the complexity of operation due to the complexity of setting the slots, based on the relationship of the electromagnetic radiation of detonation with frequency; low accuracy of measuring the propagation time of the detonation wave according to the readings of the oscilloscope.

Known devices for measuring the speed of detonation based on chronographs and oscilloscopes of various types, and also not requiring special equipment - the Dotrish method and its variants (4-6). The chronograph registers the period of time during which the detonation or explosion process passes through two or more fixed points (bases). The Dotrish method (7), adopted by the authors as a prototype, is based on comparing the determined detonation velocity with the previously known and accepted constant detonation velocity of the detonating cord, which in this case plays the role of a kind of chronograph. In this case, the detonation velocity of the explosive is calculated as the average speed over a given length of the portion of the test explosive charge. The Dotrish method is applicable only in polygon conditions on explosive charges of limited length and diameter. The disadvantage of the Dotrish method is also the low accuracy of determination due to the lack of knowledge of the exact detonation velocity of the detonating cord, the inability to measure the detonation velocity of the explosive charge in wells and at several explosive charge bases.

The technical task of the utility model was the development of a device for determining the detonation velocity of an explosive charge, which has an accuracy sufficient for practical purposes, safety, reliability and ease of use both in production conditions during blasting operations and in landfill conditions.

The indicated technical problem was solved by developing a device and its variant for determining the detonation velocity of explosive charges, consisting of a detonation pulse conductor and a chronograph, which additionally contains a connecting cable, as a chronograph - a digital one- or multi-interval electronic time meter,

- option 1 - to determine the velocity of detonation of charges in the shell during field tests -

- as a conductor of a detonation pulse contains waveguides of a non-electric blasting system of equal length introduced into the explosive charge perpendicular to its longitudinal axis at fixed distances from each other; as sensors, electrical contact sensors operating on “closure” are used, placed inside the channels of the waveguides at their ends at a predetermined distance from each other and connected via an electric cable to a digital single or multi-interval electronic time meter, the start and stop of which is carried out by signals from the sensors, closing upon contact with high-temperature products of the detonation wave front explosion, passing inside the waveguide,

- option 2 - to determine the detonation velocity of explosive charges in the well -

- as a conductor of a detonation pulse, contains detonating cords of equal length placed in insulating shells and introduced into the explosive charge parallel to its longitudinal axis, and waveguides of a non-electric explosive system of equal length connected to the detonating cord outside the explosive charge at fixed distances from each other ; as sensors, electrical contact sensors operating on “closure” are used, placed inside the channels of the waveguides at their ends at a predetermined distance from each other and connected via an electric cable to a digital one- or multi-interval electronic time meter located outside the danger zone, start and stop which is carried out by signals from sensors that close when in contact with high-temperature products of the detonation wave front explosion, passing inside the waveguide,

and the detonation velocity of the explosive charge for options 1 and 2 is calculated based on the length of the base and the time period determined by the electronic time meter when the proximity sensors are triggered on a given base, according to the formula:

,

Where:

D _BB - detonation velocity of the explosive charge, m / s;

L _BB - the length of the section of the explosive charge (base) between the centers of the installation of waveguides, m;

Δτ is the response time interval of two adjacent electrical contact sensors at the ends of the waveguides installed on the measuring base, s.

As an electronic time meter, various types of single-channel industrial electron-counting frequency meters or special programmable digital time meters with a crystal oscillator, for example ZBS-10, can be used.

The development of 2 versions of the device for determining the detonation velocity of an explosive charge is determined by the variety of its use: on explosive charges of limited dimensions in polygon conditions and in industrial conditions on quarries on well explosive charges.

The detonation velocity of an explosive by the proposed device can be determined in one or more sections (bases) located along the longitudinal axis of the charge.

Several waveguides of equal length at fixed equal distances between them can be introduced into the charge. Detonation pulse conductors must have the same length, measured to an accuracy of 1 mm.

The connecting cable between the electrical sensors and the digital electronic time meter is selected so long as to ensure the meter is placed and started outside the danger zone.

The first measuring base in the explosive charge is installed at a distance of not less than two diameters of the charge from the place of initiation of the explosive charge.

In option 2, as a conductor of the detonation pulse, a detonating cord is used together with a sample of initiating substance 6-12 g / m in an insulating shell with an open end to exclude its effect on neighboring detonating cords and an explosive with a waveguide, in order to enable the contact sensors from the detonation signal and transmitting it to an electronic time meter.

The waveguides are not placed in an insulating sheath, because they have no lateral effect of knock transmission. The detonating cords are connected to the waveguides by knitting with a “marine knot” or overlapping each other, followed by fastening them with an adhesive or insulating tape.

The essence of the utility model is illustrated in figures 1, 2.

Figure 1 - diagram of the device according to option 1:

a) a scheme for determining the detonation velocity of an explosive charge on one measuring base with two waveguides;

b) a scheme for determining the detonation velocity of an explosive charge at three measuring bases with four waveguides.

Figure 2 - diagram of the device according to option 2.

Designations:

1 - digital electronic multi-interval time meter;

2 - front panel (digital screen of an electronic time meter);

3 - explosive charge;

4 - initiating agent;

5 - waveguides;

6 - electrical contact sensors for “short circuit”, for example, two-wire copper wires in enamel insulation with a cross section with a diameter of 0.70-0.80 mm ² inserted through a puncture (hole) into the waveguide channel through which the shock wave propagates during the explosion;

7 - stranded cable;

8 - indicator LEDs showing the values of the times of the detonation process between the bases when triggered by electrical sensors;

9, 10 - functional buttons ("start", "stop");

11 - detonating cord;

12 - insulating shell of the detonating cord;

13 - the junction of the detonating cord with the waveguide;

14 - well;

15 - stemming from inert material;

16 - polymer shell explosive charge.

Features of the proposed device for determining the speed of detonation:

- the use of sensors for "circuit" installed along the waveguide at predetermined distances;

- the use of charge in the shell with installed waveguides of known length at a fixed distance between them;

- the use of a single or multi-interval electronic time meter;

- for option 2 - the use of a detonating cord as a conductor of a detonation pulse with a weight of initiating substance 6-12 g / m in an insulating sheath together with a waveguide.

The proposed device contains an explosive charge in the shell (in option 2 - in the well), at one end of which is installed initiating means 4, consisting of an intermediate detonator and / or electric detonator. It is allowed to initiate a charge with a non-electric detonator. In the test explosive charge is introduced perpendicular or parallel to the longitudinal axis of the charge waveguides 5 of the same length at the same distance from each other. The distance from the initiating means to the first waveguide is taken at least two diameters of the charge to ensure a stationary process of detonation of explosives at the measuring bases. At the free ends of the waveguides, contact sensors 6 are installed, each of which is connected via a cable 7 to a digital electronic time meter 1. Wire contact sensors are introduced into the waveguide channel so that the front of the shock wave passes through the place of their installation. Contact sensors are a pair of copper wires twisted together in enamel insulation, open at the end. When voltage is applied to the wires, current does not pass through them, because the ends of the wires are open. When a shock wave propagating through the waveguide propagating through the waveguide due to strong ionization of gases passes through the sensors, the spark gap of the sensor becomes conductive and a current arises in the circuit, which supplies a control voltage pulse for the electronic time meter to operate.

Operating procedure.

The explosive charge in the shell 3 with the means of initiation 4 (intermediate detonator) is placed on the explosive site of the test site or in the well 14 on the quarry. From the side of the means for initiating 4 explosive charge 3 at a distance of at least two diameters from it, the first waveguide 5 of known length is installed. At a fixed distance in charge, a second waveguide of the same length is installed. At the ends of the waveguides, electrical contact wire sensors are installed that are inserted into the hollow channel of the waveguide. The waveguide length and the distance between them are measured with an accuracy of 1 mm. In option 2, in a charge explosive, a detonating cord is installed in parallel with its axis in an insulating shell, fastened to a waveguide. With the aid of the initiation means, detonation of the explosive charge is excited. The detonation of the explosive charge after the acceleration section (at least 2 charge diameters) reaches a stable stationary mode with a maximum detonation speed. Detonation of the explosive charge at the meeting point with the first waveguide causes its detonation with the propagation of a shock wave along the waveguide. The detonation wave front, moving along the explosive charge, excites a shock wave in the second waveguide. Shock waves passing through the waveguide on the one hand, and along the charge and the waveguide on the other hand, alternately close the sensors installed at the ends of the waveguides. The signals from the sensors are fed to an electronic time meter - the difference in their response time (Δτ) is recorded: Δτ = τ ₂ -τ ₁ , where τ ₁ is the shock wave propagation time along the first waveguide; τ ₂ is the propagation time of the detonation wave along the portion of the explosive charge and shock wave along the second waveguide. On the panel of the digital electronic time meter, the circuit time interval between two electrical sensors (Δτ) is fixed. For waveguides of the same length L _B and the known length of the explosive charge portion L _BB between them (the base), the detonation velocity of the explosive charge is calculated from the measured response time of the electrical contact sensors using the above formula.

When using a multi-interval electronic time meter, the detonation velocity of an explosive can be determined simultaneously at several bases (sections) of charge placed along its length. In this case, waveguides of the same length are placed at fixed (identical) distances equal to the accepted value of the measuring base L _BB . Contact sensors are inserted inside the ends of the waveguides and are connected through a multicore cable to the corresponding channel of a digital electronic time meter. When triggered by electrical sensors, the meter determines the duration of the detonation process by the explosive charge at each base. With the same length of the waveguides L _B and the measuring bases L _BB , the detonation velocity is determined by the above formula.

The scheme for determining the detonation velocity of the explosive charge at three measuring bases when using the inventive device is shown in figb.

Examples of determining the detonation velocity of the explosive charge using the proposed device.

Example No. 1 (figa) - determination of the detonation velocity of the explosive charge.

When determining the detonation velocity of an explosive charge on one measuring base at a known waveguide detonation velocity, a waveguide with a detonation velocity of 1900 m / s Korshun non-electric blasting system was used. Two experimental explosions were conducted at the training ground. The waveguide lengths were used: 1) L _B = 15.58 m, and 2) L _B = 31.48 m. At the ends of each of the waveguides, one electrical contact sensor was installed per short circuit, connected by a multicore cable, respectively, to a digital electronic time meter. The length of the explosive charge section (base) between the centers of the waveguide installation was taken 1) L _BB = 0.35 m and 2) L _BB = 0.40 m, respectively, for the first and second experiments. The diameter of the test explosive charge d = 0.10 m. The charge was placed in a polyethylene shell. Granulite RP was used as an explosive. The distance from the initiating means to the installation center of the 1st waveguide is 0.25 m.

The detonation velocity of the explosive charge is calculated by the formula: .

The results of determining the detonation velocity of the explosive charge are presented in table 1.

Table 1. Experience number Indicators L _B. , M L _BB , m Δτ, s D _BB , m / s The average value of D _BB , m / s one 15,58 0.350 0,0095196 2100 2212.5 ± 12.5 2 31.48 0.400 0,0003778 2125

Example No. 2 - determination of the detonation velocity of an explosive charge in a well at a quarry at two measuring bases at a known waveguide detonation velocity.

The borehole diameter is 0.25 m, the charge length is 10 m, the stemming length is 7 m, the base is 1 m, explosive is granulite RP. The gunman was installed at the bottom of the well, at a distance of 1.5 m from the gunman, the first detonating cord 11 m long was placed along the charge axis in height; at a distance of 1 m from the installation site of the 1st detonating cord along the height along the axis of the charge, the second detonating cord was placed 11 m long, and then at a distance of 1 m from the installation site of the 2nd detonating cord along the height along the axis of the charge was placed the 3rd detonating cord 11 m long. Each of the detonating cords was connected by a “sea knot” to a waveguide 100 m long, at the ends of which electrical contact sensors were inserted, which were connected with a 100 m long multicore cable to a ZBS-10 digital electronic time meter.

The detonation velocity of the explosive charge is calculated by the formula: .

The results of determining the detonation velocity of the explosive charge are presented in table 2.

Table 2. Experience number Indicators L _B , m L _BB , m Δτ, s D _BB , m / s Average D _BB , m / s one 100.00 1,000 0,0002632 3800 3815 ± 15 100.00 1,000 0,0002611 3830

The proposed device for determining the detonation velocity of an explosive provides the claimed technical result:

- accuracy, simplicity of determining the detonation velocity of an explosive charge through the use of electrical sensors and digital electronic time meters;

- work safety through the use of a waveguide with a detonation velocity of ~ 2000 m / s, which does not have an air wave and does not have a mechanical impact on the environment. This allows you to increase the length of the measuring line and place a digital electronic time meter and to undermine the charge beyond the border of the danger zone by the action of the explosion;

- for option 2 - the accuracy, speed and safety of determining the detonation velocity of an explosive charge on a quarry, which allows you to calculate the parameters of explosive charges, plan and control the energy of the explosion during blasting.

The proposed device passed an industrial test to determine the detonation velocities of explosive charges produced at blasting sites, as well as those supplied by manufacturers of explosive materials in the mine and production quarry conditions, which makes it possible to optimize charge parameters and explosion conditions in quarries.

Information sources

1 AU USSR No. 389294

2 Dubnov L.V., Bakharevich N.S., Romanov A.I. "Industrial explosives", M., "Nedra", 1988.

3 RF Patent No. 3852994

4 USSR AS No. 297924

5 US Patent No. 3572095

6 AU USSR No. 743395

7 GOST 3250-

Claims (10)

1. A device for determining the detonation velocity of explosive charges in the shell, consisting of a detonation pulse conductor and a chronograph, characterized in that it additionally contains a connecting cable, as a chronograph - a digital single or multi-interval electronic time meter, as a detonation pulse conductor - waveguides of a non-electric blasting system of equal length introduced into the explosive charge perpendicular to its longitudinal axis at fixed distances from each other ; as sensors, electrical contact sensors operating on “closure” are used, placed inside the channels of the waveguides at their ends at a predetermined distance from each other and connected via an electric cable to a digital single or multi-interval electronic time meter, the start and stop of which is carried out by signals from the sensors, when the front of the shock wave passes through the waveguide, and the detonation velocity of the explosive charge is calculated based on the length of the base and the time period electrocontact sensors, according to the formula:

where D _BB is the detonation velocity of the explosive charge, m / s; L _BB - the length of the section of the explosive charge (base) between the centers of the installation of waveguides, m; Δτ is the response time interval of two adjacent electrical contact sensors at the ends of the waveguides installed on the measuring base, s. 2. The device according to claim 1, characterized in that it comprises, as an electronic time meter, single-interval industrial electronic counting frequency meters. 3. The device according to claim 1, characterized in that it contains as an electronic time meter a multi-interval programmable detonation velocity meter with a crystal oscillator, for example, ZBS-10. 4. The device according to claim 1, characterized in that it can determine the detonation velocity of an explosive in one or more sections (bases) located along the longitudinal axis of the charge. 5. A device for determining the detonation velocity of explosive charges in a well, consisting of a detonation pulse conductor and a chronograph, characterized in that it further comprises a connecting cable, as a chronograph, a digital one- or multi-interval electronic time meter, and as a detonation pulse conductor detonating cords of equal length, placed in the explosive charge in the insulating shell, introduced into the explosive charge parallel to its longitudinal d axis, and waveguides nonelectrical system blasting equal length, connected to a detonating cord outside the explosive charge at fixed distances from each other; as sensors, electrical contact sensors operating on “closure” are used, placed inside the channels of the waveguides at their ends at a predetermined distance from each other and connected via an electric cable to a digital one- or multi-interval electronic time meter located outside the danger zone, start and stop which is carried out by signals from sensors that close when the front of the shock wave passes through the waveguide, and the detonation velocity of the explosive charge is calculated, the outcome of base and the response time interval length electrocontact sensors according to the formula:

where D _BB is the detonation velocity of the explosive charge, m / s; L _BB - the length of the section of the explosive charge (base) between the centers of the installation of waveguides, m; Δτ is the response time interval of two adjacent electrical contact sensors at the ends of the waveguides installed on the measuring base, s. 6. The device according to claim 5, characterized in that it comprises, as an electronic time meter, one-interval industrial electronic counting frequency meters. 7. The device according to claim 5, characterized in that it contains as an electronic time meter a multi-interval programmable detonation velocity meter with a crystal oscillator, for example, ZBS-10. 8. The device according to claim 5, characterized in that it can determine the detonation velocity of an explosive in one or more sections (bases) located along the longitudinal axis of the charge. 9. The device according to claim 5, characterized in that the detonating cord is taken with a weight of initiating explosive 6-12 g / m 10. The device according to claim 5, characterized in that the connection of the detonating cord with the waveguide is made by knitting with a "marine knot" or overlapping each other, followed by fastening them using an adhesive or insulation tape.