RU2599662C2 - Method for making detonating cord and device for implementation thereof - Google Patents

Abstract

FIELD: blasting operations.

SUBSTANCE: invention relates to production of explosives, particularly of detonating cords (DC), and to equipment. DC is made by forming core from powdered explosive, by performing thread braidings and protective layer of waterproof material. Water-resistant shell is formed either continuously during forming the DC core and performing thread braidings or separately after forming the DC and performing thread braidings. Drive threads are not used. Cord core is formed during uniform filling the first braiding representing a tube ("sleeve") with constant inner diameter with explosive, first braiding is produced from several stretched longitudinal flat threads in the cord core forming device. Explosive is fed into the first braiding by means of a dispenser, performance of which is controlled depending on the explosive charge in the cord. Flat synthetic non-fibrillated threads are used as longitudinal threads of the first braiding of the cord core. Longitudinal threads from the cord core forming device cord and to the receiving station is strongly stretched along the axis to seal the core. At high charges, to avoid certain explosive layers shift inside the first braiding during sealing the cord for reinforcement of the cord core one or several longitudinal threads passed inside the first braiding are used.

EFFECT: method and device for production of detonating cord provide stability of explosive dosing, uniform filling of the DC core with explosive, possibility of rapid change of the cord charge, elimination of caving through explosive shells during fabrication, creating stretching force along the entire length along the axis of the cord for sealing the core with adjustment of force value, equality of DC rolling speed on a coil of the receiving station and speed of cord drawing, rapid change of process modes parameters using a feedback mode.

16 cl, 12 dwg

Description

The invention relates to methods for the manufacture of detonating cords and to a technique for equipping explosive devices.

Detonating cords have a multilayer structure. The detonating cord (LH) contains one or more leading threads inside the core of free-flowing explosives (BB), which is surrounded by several windings (braids) of synthetic, cotton or linen threads of various weaving, and a layer of polymer serves as the outer protective sheath (patent SU 1616059 C1 dated December 10, 1995).

An example of a method for manufacturing a detonating cord is a method for manufacturing a detonating cord according to RU 2065847 C1 of 08.27.1996, which consists in forming a core of a powder explosive with a leading thread, applying filamentous braids and protective layers of waterproof material on it.

The disadvantage of this method is that the threads used in the braiding process are often twisted, form hairpieces that overlap the backfill channel, which leads to the marriage of the cord and subsequently to the failure of the cord.

Closest to the claimed invention is patent RU 2167844 C2 dated 05/27/2001, which describes a method for manufacturing a detonating cord, which consists in forming a core from a powder explosive using a lead thread, applying filamentous braids on it and a waterproof sheath made of a polymeric material, while the formation of a waterproof shell of a polymeric material is carried out continuously with the formation of the core. A device that implements this method contains a feed funnel into which powdered explosive is poured, a DS core formation channel located below the feed funnel, spools with a lead thread passing through the feed funnel and a DS core formation channel, spools with threads of the first and second braids, moreover, the threads of the first braid pass through the channel for forming the core of the ДС, an extruder, a cooling bath, a pulling device, and a receiving device (not shown in the figure in patent RU 2167844 C2 of May 27, 2001).

This method and device for the manufacture of a detonating cord is taken as a prototype.

The disadvantages of this method and device for its implementation:

- the necessary stability of the dosing of the explosive is not ensured due to an uncontrolled change in the flow of the explosive from the feed opening of the loading funnel, while there is a large dependence of the quantity of dosing explosive on the height of the explosive in the loading funnel, as well as on the number and diameter of the leading threads;

- changing the weight of the cord within the tolerance is impossible without changing the diameter of the channel forming the core of the LH (calibrating tool), which entails a partial disassembly of the device and the refueling of all braid threads;

- due to the lack of necessary tension of the longitudinal threads of the first braid in areas from coils with longitudinal threads to the caliber of the second braid, as well as the use of fibrillated threads for the first braid, when the cord exits the channel for forming the LH core, a partial loss of continuity of the first shell occurs, which leads to shedding of explosives, which leads to a sharp decrease in the level of safety in the manufacture of the cord and to instability of the explosives in the cylinder (the number of explosives per unit length of the cord) and, accordingly, to reduce the reliability of operation ation LH. This is especially pronounced for LH with a weight of 20 g / m or more;

- when bending, for example, when pulling the LH around the bypass rollers, the base of the cord obtained by this method and on this device may lose the continuity of the shells, which leads to the shedding of explosives. This leads to a sharp decrease in the level of safety in the manufacture of the cord and to instability of the explosive hinge in the DS and, accordingly, to a decrease in the reliability of the DS operation. To avoid this, it is necessary to increase the volume of threads in the shells, or increase the number of shells, or, as suggested in this case, immediately after applying the braids, apply a polymer shell. With the simultaneous application of a polymer waterproof membrane due to the shedding of explosives described above, more intense pollution of the coolant with highly toxic explosives occurs, which requires more powerful cleaning devices;

- the friction transmission in the receiving station does not provide the necessary regulation of the speed of winding the DS on the coil of the receiving station, maintaining a stable tensile force of the DS when winding the DS on the coil, creating the necessary tensile force along the axis of the cord to seal the core. When loosening the clamps of the friction clutch of the receiving station, sufficient elongation force of the LH is not achieved, while tightening the cheeks of the clutch of the receiving station as the LR is wound onto the reel, the winding speed increases, and the underlying layers of the cord on the reel experience an increasing compression force;

- if it is necessary to change the parameters of technological modes (changing the speed of linear broaching, changing the speed of disks with coils of the second and subsequent braids, etc.), a partial disassembly of the device is necessary with the replacement of certain gears and pulleys.

The objective of the invention is to develop a method of manufacturing a detonating cord and to create a device for its implementation, which provided the necessary stability for the dosage of explosives, efficient and uniform filling of the core of the LH with bulk material, it was possible to conveniently and quickly change the weight of the cord, it was prevented from dropping through the shell of the explosive during manufacture , including when pulling through the bypass rollers, the necessary tensile force was created along the entire length of the cord and along the axis of the cord to seal the core with the possibility of regulating the magnitude of this effort, it was possible to equalize the speed of winding the DS on the coil of the receiving station with the speed of the cord, there was a convenient and quick possibility to change the parameters of the technological modes (change the speed of the linear pull, change the speed of the disks with coils of the second and subsequent braids, changes in the values of the on-delay at start-up, shutdown at shutdown, etc.) with the possibility of applying the feedback mode.

The problem is solved due to the fact that in the proposed method for the manufacture of DS, which consists in the formation of a core of powdered explosive of the blasting group: PETN, pentolite, hexogen, HMX, the execution of filaments and a protective layer of a waterproof material, a waterproof shell made of a polymer material: plastic polyvinyl chloride, composition of polyethylene, desmopan, surlyne, fluoroplastic, nylon, thermoplastic polyurethane, teflon - is formed either continuously, that is, directly but after forming a core of powdered explosive and performing filaments of braids, or separately after forming a core of powdered explosive and filaments of braids, leading threads are not used, and the core of the cord of explosive is formed when the first braid, which is a tube, is uniformly filled with explosive ("Stocking") with a constant inner diameter, created from several stretched longitudinal flat threads in a heart forming device cord in the form of a funnel of variable taper height with a die plate in the lower part, while the explosive is fed into the first braid using a dispenser, the performance of which is regulated depending on the required weight of the explosive in the cord, that is, the amount of explosive per unit length cord. As the longitudinal filaments of the first braid of the powder explosive core, flat synthetic non-fibrillated filaments are used, while the longitudinal filaments from the cord core forming apparatus to the receiving station are subjected to strong tension along the axis to seal the core. For large weights, in order to avoid shear of individual explosive layers inside the first braid, when sealing the cord, one or more longitudinal threads are used to extend (reinforce) the core of the cord, stretched inside the first braid. A device for manufacturing a detonating cord consists of reel holders for reels with first braid threads, a loading funnel with powdered explosive material, sealing gauges, rotating disks for installing reels with second and subsequent braids, a pulling device, a receiving station with replaceable coils for the finished cord or its basis. To form the core of the cord from explosive material, uniformly filling the first braid of several stretched longitudinal flat threads, which is a tube ("stocking") with a constant inner diameter, a cord core forming device is used in the form of a funnel, variable in taper height, with a die plate in the lower part, while the explosive material is continuously fed into the first braid using a dispenser, the performance of which is regulated depending on the required weight of the explosive eschestva in a string. The dispenser is made in the form of a feeding pyramid or cone-shaped vibro-hopper with a metering outlet, of a variable size, in the lower part of the vibro-hopper and a metering element made in the form of a roller, either a conveyor belt, or a vibratory feeder and located under the hopper outlet. The loading funnel, made in the form of an inverted cone, has a hole in the lower part that can be opened and closed by a valve by a signal from a level sensor installed in the metering vibratory hopper. Between the dispenser and the device for forming the core of the cord, a device is installed in the form of a vibratory funnel, or in the form of several vibratory trays, which makes it possible to average (smooth) some fluctuations in the amount of explosive material poured per unit time, inevitable when bulk material expires. The spool holders for spools with first braid yarns have adjustable brakes, which allow braking with reels of the first braid yarns at a certain moment and thereby create tensile forces along the longitudinal threads to obtain the first braid in the form of a tube (“stocking”) with a constant inner diameter. After the last sealing gauge, a digital cord diameter meter is installed, showing the current value of the diameter of the cord, recording the current values of the diameter of the cord in the device’s memory at specified intervals, determining the current value of the explosive sample in the cord and having a feedback control connection with the dispenser, allowing quick change the performance of the dispenser to support a given amount of explosive in the cord. During the continuous formation of a waterproof shell made of polymer material, a pulling device is installed in the cooling bath, and an extruder is installed between the digital cord diameter meter and the cooling bath with the pulling device for applying the waterproof shell to the cord base. When the waterproof membrane is separately formed from a polymeric material, the coating on the cord base is carried out in a separately installed extruder, after which the cord is cooled in a cooling bath, also separately installed, and the finished cord is wound on a replaceable coil. A compensator is installed between the pulling device and the receiving station, equalizing the linear speeds of the pulling device and winding onto the removable coil of the receiving station, and also, when used together with the pulling device, creates a stable and adjustable tensile force along the cord axis to seal the core, while the friction in the receiving station is missing. To perform each layer of braiding, longitudinal pulling of the cord and winding the cord onto the replaceable coil of the receiving station, individual drives with the control of each drive through a frequency converter are used, and a stepper motor with an individual control circuit is used to drive the dispenser. Management of all operating modes of the device is carried out using a software package created on the basis of a programmable controller.

The technical result of the claimed invention is to obtain a cheap, reliable, safe and easy-to-use detonating cord with stable explosive samples in the cord from 4 g / m to 150 g / m over the entire length of the cord, a detonation speed of up to 7 km / s or more, providing reliable shelter of the core of the cord by the thread-like shells, eliminating the shedding of explosives during manufacture, including pulling through the bypass rollers, providing a convenient and efficient possibility of changing the parameters of the technological their modes using the feedback mode between the parameters of the cord and the parameters of the technological mode.

A device implementing the proposed method for manufacturing a DS is depicted in FIG. 1 ... FIG. 12, where:

1 - loading funnel;

2 - dispenser;

3 - dosing element: in the form of a roller in FIG. 1 and FIG. four; in the form of a conveyor belt in FIG. 2 and FIG. 5; in the form of a vibratory feeder in FIG. 3 and FIG. 6;

4 - averaging device: in the form of a vibro-funnel in FIG. 1, FIG. 2 and FIG. 3; in the form of several vibratory traps in FIG. 4, FIG. 5 and in FIG. 6;

5 - a device for forming a core of a cord;

6 - reel holders for spools of first braid;

7 - longitudinal reinforcing thread;

8 - sealing gauges;

9 - rotating disks for installing coils with threads of the second and subsequent braids;

10 - digital meter diameter of the cord;

11 - extruder;

12 - cooling bath;

13 - pulling device;

14 - compensator;

15 - receiving station with a removable coil for winding the cord;

16 - control cabinet;

17 - drive bath cooling;

18 - giving device;

19 - winding device.

The dispenser 2 is made in the form of a supplying pyramid or cone-shaped vibratory hopper with a variable-sized dispensing outlet at the bottom of the vibratory hopper.

The dispensing element 3 is located under the outlet of the vibratory hopper of the dispenser and is made either in the form of a roller, as in FIG. 1, FIG. 4, FIG. 7 and FIG. 10, or in the form of a conveyor belt, as in FIG. 2, FIG. 5, FIG. 8 and FIG. 11, or in the form of a vibratory feeder, as in FIG. 3, FIG. 6, FIG. 9 and FIG. 12.

The loading funnel 1 is made in the form of an inverted cone, in the lower part of which there is an opening opened by the valve by a signal from a level sensor installed in the metering vibratory hopper.

Averaging device 4 allows you to average (smooth) some fluctuations in the amount of poured explosive material per unit time, inevitable when the bulk material expires. The averaging device is either in the form of a vibratory funnel, as in FIG. 1, FIG. 2, FIG. 3, FIG. 7, FIG. 8 and in FIG. 9, or in the form of several vibratory trays, as in FIG. 4, FIG. 5, FIG. 6, FIG. 10, FIG. 11 and in FIG. 12.

The device for forming the core of cord 5 is made in the form of a funnel with a die plate in the lower part and serves to form a tube (“stocking”) with a constant inner diameter from several stretched longitudinal flat threads.

The spool holders for spools with first braid yarns 6 have adjustable brakes that allow braking of spools with first braid yarns and thereby contribute to the creation of a tensile force along the axis of the cord to seal the core.

Longitudinal reinforcing yarn 7 or several yarns are used for large weights in order to avoid displacement of individual explosive layers inside the first braid when sealing the cord to strengthen (reinforce) the core of the cord. The reinforcing thread or threads are stretched inside the first braid when forming the core of the cord.

A digital cord diameter meter 10 shows the current value of the diameter of the cord, writes the current values of the cord diameter to the device memory at specified intervals, determines the current value of the explosive sample in the cord from the measurements and has a feedback control connection with the dispenser, allowing you to quickly change the performance of the dispenser to support a predetermined quantity of explosives in the cord.

The compensator 14 equalizes the linear speeds of the pulling device and winding on the removable coil of the receiving station, and also contributes to the use of the pulling device to create a tensile force along the axis of the cord to seal the core.

To carry out each braiding layer, longitudinal pulling of the cord and winding the cord onto the replaceable coil of the receiving station, individual drives with control of each drive through a frequency converter were used, and a stepper motor with an individual control circuit was used to drive the dispenser.

Management of all operating modes of the device is carried out using a software package created on the basis of a programmable controller.

A device that implements the proposed method for the manufacture of LH works as follows. When the valve is opened in the lower part of the loading funnel 1, the explosive is poured into the dispenser 2, then through the dispensing slot of the dispenser it enters the dispensing element 3, from which through the averaging device 4 it is uniformly and accurately dispensed into the “stocking” from the pre-tensioned cord 5 due to the work of the brakes of the reel seat 6 flat threads of the first braid, while there is a preliminary compaction of explosives. With large weights, one or more reinforcing threads 7 are pulled through the core of the cord 7. After that, the subsequent and final compaction of explosives is carried out by perpendicular, in the direction of movement of the cord, braiding with threads from disks 9 and pulling through gauges 8. Next, the cord passes through a digital meter for measuring the diameter of the cord 10, which shows the current value of the diameter of the cord on the display of the control cabinet 16, writes the current values of the diameter of the cord to the device memory at predetermined intervals, determines the current value of the explosive sample in the cord from the measurements and, if necessary , quickly changes the performance of the dispenser to support a given amount of explosives in the cord. Then, in the presence of an extruder 11, the cord is passed through its head with the subsequent application of the polymer sheath, in the cooling bath 12 the shape of the LH is fixed and the pulling device 13, through the compensator 14, is supplied to the removable coil of the receiving station 15. When the polymer sheath is separately applied, the cord is pulled through pulling device 13 and through the compensator 14 is issued to a replaceable coil of the receiving station 15. Then, the replaceable coil with a cord is installed in the transfer device 18, the cord is passed through the head of the extruder 11 followed by applying a polymer shell, in the cooling bath 12 the LH shape is fixed and the cooling bath drive 17 provides the finished cord to the removable coil of the winding device 19. The compensator 14, equalizing the linear speeds of the pulling device 12 and the winding to the removable coil of the receiving station 15, simultaneously creates a certain the tension force of the cord at the outlet of the towing device 12, thereby maintaining a consistently high pull force at the entrance to the towing device 12. The design of the compensator 14 allows you to change violence up cord tension at the exit from the pulling device 12 that allows adjusting the magnitude of the tensile force acting on the cord. Using a software package created on the basis of a programmable controller, the parameters of technological modes and a set of protective locks are set and quickly changed with high accuracy. The controller and the main part of the automation devices are located in the control cabinet 16.

A detonating cord with a weight of 80 g / m, manufactured according to the claimed method, was able to withstand a breaking load of at least 120 kg and showed a detonation speed of about 6.8 km / s.

Claims (16)

1. A method of manufacturing a detonating cord, which consists in forming a core of powdered explosive, making filaments and a protective layer of a waterproof material, characterized in that the waterproof shell of a polymeric material is formed continuously with the formation of a core of powdered explosive and making braiding, and separately after the formation of a core of powdered explosive and the execution of filaments, leading threads for no explosives are fed from the hopper feeder feeder, and the core of the explosive cord is obtained by uniformly filling the first braid with the explosive, which is a tube (“stocking”) with a constant inner diameter created from several stretched longitudinal flat threads in the cord core forming device in the form of a funnel, variable in height of the taper, with a die-caliber in the lower part, while the explosive is fed into the first braid using a dispenser, make nost is regulated depending on the desired linkage in the explosive cord (quantity of explosive material per unit length of the cord). 2. The method according to p. 1, characterized in that as the longitudinal threads of the first braid of the core of the powdered explosive use flat synthetic non-fibrillated threads. 3. The method according to p. 1, characterized in that the longitudinal threads from the device for forming the core of the cord and to the receiving station are subjected to strong tension along the axis to seal the core. 4. The method according to p. 1, characterized in that when large weights in order to avoid shear of individual layers of explosives inside the first braid when sealing the cord to strengthen (reinforce) the core of the cord use one or more longitudinal threads stretched inside the first braid. 5. A device for the manufacture of a detonating cord, consisting of reel holders for coils with first braid threads, a loading funnel with powdered explosive material, sealing gauges, rotating disks for installing coils with second and subsequent braids, extruder, pull device, cooling bath, receiving station with replaceable coils for the finished cord or its base, characterized in that for the formation of the core of the cord of explosive material, uniformly filling the first braid of several of tapered longitudinal flat threads, which is a tube ("stocking") with a constant inner diameter, a cord core forming device is used in the form of a funnel, variable in taper height, with a caliber die in the lower part, while the explosive material is continuously fed into the first braid with using a dispenser, the performance of which is regulated depending on the required weight of the explosive in the cord. 6. The device according to claim 5, characterized in that the dispenser is made in the form of a feeding pyramid or cone-shaped vibro-hopper with a metering outlet, of a variable size, in the lower part of the vibro-hopper and a metering element made in the form of a roller and located under the outlet of the hopper. 7. The device according to claim 5, characterized in that the dispenser is made in the form of a feeding pyramid or cone-shaped vibro-hopper with a metering outlet, of a variable size, in the lower part of the vibro-hopper and a metering element, made in the form of a conveyor belt and located under the outlet of the hopper. 8. The device according to claim 5, characterized in that the dispenser is made in the form of a feeding pyramid or cone-shaped vibro-hopper with a metering outlet, of a variable size, in the lower part of the vibro-hopper and a metering element made in the form of a vibratory feeder and located under the hopper outlet. 9. The device according to claim 5, characterized in that the loading funnel, made in the form of an inverted cone, has a hole in the lower part that can be opened and closed by the valve upon a signal from a level sensor installed in the dispenser supply vibro-hopper. 10. The device according to p. 5, characterized in that between the dispenser and the device for forming the core of the cord a device is installed in the form of a vibratory funnel, which allows one to average (smooth) some fluctuations in the amount of explosive material poured per unit time, inevitable when bulk material expires. 11. The device according to p. 5, characterized in that between the dispenser and the device for forming the core of the cord is installed averaging device in the form of several vibratory trays. 12. The device according to claim 5, characterized in that the spool holders for spools with first braid yarns have adjustable brakes that allow braking with reels of the first braid at a certain moment and thereby create tensile forces along the longitudinal threads to obtain the first braid in the form of a tube ( "Stocking") with a constant inner diameter. 13. The device according to claim 5, characterized in that after the last sealing gauge a digital cord diameter meter is installed, showing the current value of the cord diameter, recording the current values of the cord diameter in the device’s memory at predetermined time intervals, which determines the current explosive charge size from the measurements in the cord and having a feedback control connection with the dispenser, which allows you to quickly change the performance of the dispenser to support a given amount of explosive material wa in the cord. 14. The device according to claim 5, characterized in that a compensator is installed between the pulling device and the receiving station, equalizing the linear speeds of the pulling device and winding onto the removable coil of the receiving station, as well as contributing to the creation of a stable and adjustable tensile force when used with the pulling device along the axis of the cord to seal the core, with no friction in the receiving station. 15. The device according to p. 5, characterized in that for each layer of braiding, longitudinal pulling the cord and winding the cord onto a removable coil of the receiving station, individual drives with the control of each drive through a frequency converter are used, and a stepper motor with an individual circuit is used to drive the dispenser management. 16. The device according to p. 5, characterized in that the control of all modes of operation of the device is carried out using a software package created on the basis of a programmable controller.

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