RU2427711C1 - Device for undercutting slabs of rock with electric discharges - Google Patents

Abstract

FIELD: mining engineering.

SUBSTANCE: device consists of alternating high voltage and grounded core electrodes located in one plane and held with upper and lower holders. A lower holder is of a wedge shape with tapered guiding electrode channels, with slime windows between theses channels and with face supports. Bare parts of electrodes are made in form of hinged sections. The upper holder travels in guides along electrodes.

EFFECT: expanded functionality of device, reduced expenditures.

3 cl, 5 dwg

Description

The invention relates to the field of production of building materials and to the mining industry for cutting blocks of rock during their extraction in quarries and core cutting in trunks and boreholes of large diameter by an electric pulse method, i.e. with the help of high-voltage discharges, developing directly in the rock and destroying it.

A similar device is known that makes it possible to cut a rock layer with electric discharges (B. S. Blaznin, I. A. Shchegolev, L. I. Lozin, V. M. Adam, S. V. Romakin “Processing of natural stone with electric discharges”. Journal "Electronic Processing of Materials", 1983, No. 1, pp. 5-7). The main element of this device is a multi-electrode system with alternating rod high-voltage and grounded electrodes located in parallel with an equal distance between adjacent electrodes. The housing of the device is an insulator, to the bottom of which is attached a holder of a grounded electrode system, and to the top of the insulator is attached a holder of high-voltage electrodes having a "g" -shaped shape. A wire with high voltage insulation is connected to the holder of the high voltage electrodes to supply high voltage pulses to these electrodes. A tool holder is rigidly attached to the insulator to move the device.

The main disadvantage of this device is as follows. The device is intended for periodic cutting by an electric pulse method only part of the surface layer of rock blocks, and for cutting at a depth you need to go through such a lateral vertical gap along a future rock block or such an annular excavation around a large diameter core that has a width slightly larger than the length of an analog device so that you can place this device on the bottom of a slit or ring hole perpendicular to the cut block of rock or core. Thus, in order to use the known device for cutting at depth, it is necessary to carry out a large amount of work on the destruction of the rock in the side slit or ring excavation and extraction of the destroyed rock from them, and the greater the greater the length of the known device.

Closest to the proposed device by the number of common essential features is a prototype device designed to destroy the surface layer of articles made of artificial materials and natural stone by electric discharges (RF patent for utility model No. 81258, IPC E21s 37/18, publ. March 10, 2009 .), which is quite applicable for the sinking of cracks in rocks. It contains alternating high-voltage and grounded rod electrodes located in one plane and fastened by upper and lower holders, each of which is made with an insulating coating; in addition, it contains guides, and its lower holder is made with the possibility of adjustable movement along these guides along flexible and elastic electrodes, the lower ends of the insulation coatings of the electrodes provided with protective shields, the length of the bottom-hole exposed part of each electrode is not more than 0.3 distance between two adjacent bipolar electrodes, grounded or grounded and high voltage electrodes are made in the form of tubes, and the electrodes can be arranged in several rows.

The main disadvantage of the device is that when cutting blocks of rocks or large diameter cores at a depth from the bottom of the vertical side slit or from the bottom of the ring working around the core, this device must be placed horizontally on the bottom, like the analog, so that the electrodes are perpendicular to the cut block or core. But in order to position the device on the bottom, it is necessary to carry out a large amount of work on driving such a wide gap or such a wide annular mine.

The technical result of the proposed device is that it allows cutting at its vertical initial position with a slit or annular width of a slightly larger thickness of the proposed device, rather than length, as when using an analog or prototype, and since the thickness of the device is several times smaller than it length, then the volume of destructible and recoverable rock is reduced several times during the sinking of the vertical lateral slit or ring work, from which the cutting process of the proposed device is conducted.

The specified technical result is achieved by the fact that in the device for cutting rock blocks by electric discharges, comprising alternating high-voltage and grounded rod electrodes located in the same plane and fastened by upper and lower holders, one of the holders being made with the possibility of moving along the guides along the electrodes, according to the proposed solution, the lower holder is made wedge-shaped with inclined guide electrode channels, with slurry windows between these channels and c downhole supports, bare portions of the electrodes are in the form of hinged sections, and the upper holder is movable on guides along the electrodes.

It is advisable to tilt the guide electrode channels in the lower holder to perform from two opposite sides.

It is also advisable to perform bottomhole electrode sections from conductive cables.

An example of a specific implementation of the proposed device is illustrated by drawings. Figure 1 shows its front view, figure 2 and figure 3 shows a longitudinal section through a high-voltage electrode in the initial (figure 2) and working (figure 3) positions, figure 4 shows a longitudinal section (in the working position ) a device in which the inclined guide electrode channels in the lower holder are made from two opposite sides thereof; figure 5, as in figure 2, shows a longitudinal section of the device along the high-voltage electrode, but in contrast to figure 2, figure 5 bottom-hole sections of the electrodes are made of conductive cables.

The device (figure 1) consists of alternating high-voltage 1 and grounded 2 rod electrodes located in the same plane. All electrodes are fastened by the upper 3 and lower 4 holders, and the upper holder 3 is made with the possibility of free longitudinal (along the electrodes) movement along two guides 5, for which the lower ends of the guides 5 are rigidly fixed in the lower holder 4, and their upper ends are freely passed through holes in the upper holder 3. The lower holder 4 is made wedge-shaped (figure 2 ÷ 5) with inclined guide electrode channels 6 (figure 1 ÷ 5). In Fig. 1 ÷ 4, the channels 6 in the lower holder 4 are made in the form of grooves, and in Fig. 5 - in the form of holes directed towards the cutting of rocks. In Fig.4 inclined guide electrode channels 6 are made in the lower holder 4 from two opposite sides. Between each pair of inclined guide rails of the electrode channels 6 (Fig. 1), slurry windows 7 are made in the lower holder 4. To prevent sludge from accumulating in these windows, the lower holder 4 is always above the bottom in an elevated position, for which two lateral bottom holes are attached to it from below support 8 (figure 1 ÷ 5). The working parts of all the electrodes are made in the form of articulated sections 9 (Fig. 1), and the articulated sections of the electrodes are connected so that they can rotate relative to each other only in the direction of inclination of the guide electrode channels 6, which is clearly seen in Fig.3 and Fig. four. A feature of the electrodes, one of which is shown in FIG. 5, is that their bottom-hole sections are made of conductive cables 10, for which the guide electrode channels 6 are made in the form of holes directed towards the cutting of rocks, which eliminates the loss of cables from the channels . To prevent precipitation of the electrodes from the channels 6, made in the form of gutters (figure 1 ÷ 4), above them to the lower holder 4 is attached a plate limiter 11 made of an elastic material (rubber). Parts of the electrodes above their upper articulated joints of the sections are provided with insulating coatings 12 (Fig. 1). With an insulating coating 13, a jumper 14 of high-voltage electrodes 1 is made. The upper ends of the grounded electrodes 2 are fixed in the support platform 15 and are electrically connected by a bus 16. The support platform 15, the upper and lower holders 3 and 4, and also the guides 5 are made of fiberglass. Grounded and high voltage electrodes 2 and 1, as well as jumper 14 are made of stainless steel rods with a diameter of 10 mm. The diameter of the conductive cables 10 (figure 5) is also 10 mm The insulation coatings of the electrodes 12 and the coating of the jumper 13 have an outer diameter of 44 mm. The material of all insulation coatings is high pressure polyethylene. The distance between two adjacent bipolar electrodes is 80 mm, the largest width of the device (Fig. 1) is 430 mm, and its height (to the top surface of the supporting platform 15) is 600 mm. The thickness of the device is mainly determined by the thickness of the lower holder 4. The thickness of the device shown in figures 1, 2, 3 and 5 is 58 mm, and in figure 4 it is about 90 mm. In addition to the above elements of the device, all the drawings show a vertical side slit 17, and in FIGS. 3 and 4, cutting slots 18 and the resulting slurry 19 are shown.

The operation of the proposed device is as follows. The device is installed on the bottom of the vertical side slit 17, previously passed in the rock using an electric discharge cutter, similar in design to that given in the article: Vazhov V.F., Zhurkov M.Yu., Lopatin V.V., Muratov V.M. "Electric discharge cutting of rocks." The journal "Physico-technical problems of mining", 2008, No. 2, p. 71, Fig. 1, b. The gap 17 is filled with water (or dielectric fluid) to a level above the jumper 14 of the high-voltage electrodes 1. With liquid leaks in the gap 17, this level is maintained so as to prevent electrical breakdowns of the liquid between the exposed parts of the electrodes 1 and 2 and to prevent the development of discharges on the surface of the device elements. Then one of the grounded electrodes 2 (Fig. 1) is grounded, a load of dielectric material (not shown) is placed on top of the support pad 15 or a force of 10-15 kg is applied to it in another way and high voltage pulses are applied to the high-voltage electrodes 1: for granite 380 kV, for sandstone with calcareous cement 260 kV. The frequency of the pulses in the absence of a flushing system is 2-3 pulses per second. When using a flushing system (not shown), the frequency of the effective supply of pulses exceeds 10 pulses / s. When high-voltage pulses are applied between the ends of the high-voltage 1 and grounded 2 electrodes in the rock, discharges develop that tear off the rock, and the resulting slurry is discharged by 19 bits from the resulting cutting slit 18, including through slurry windows 7, to the bottom of the vertical slit 17 in the space between the supports 8. The device sequentially moves from the starting position (figure 2) to the final position (figure 3). In the process of formation of the cutting gap 18, the lower holder 4, its supports 8 and guides 5 remain stationary, and all other elements of the device under the influence of the load fall down. In this case, the articulated sections 9 of the electrodes 1 and 2, sliding along the inclined guide electrode channels 6, rotate relative to each other and occupy the position shown in figure 3, or in figure 4 (when performing the lower holder 4 with channels 6 with two of it opposite sides), or in Fig. 5: when making bottom-hole electrode sections in the form of conductive cables 10. After driving the cutting slot 18, the supply of high voltage pulses is stopped, the device is raised above the bottom of the vertical slot 17 and installed next to azovavsheysya scoring slit 18, to eventually obtain scoring slit the entire length of the face vertical side slit 17. Then the device is recovered and in a vertical side slot 17 and scoring slit 18 via gidroklina carried spall undercut rock block. In the same way, after multiple cutting of a large diameter core, it can be chipped, which ultimately will allow several times to reduce costs for the extraction of all core material. The proposed device with a thickness of 58 mm covered slits in coarse-grained granite with a depth of up to 300 mm, and in sandstone with calcareous cement up to 400 mm from a sixty-millimeter vertical gap. In order to drive such cutting gaps with the prototype device, such a gap is necessary so that a device with a height of 350-450 mm can be placed on its bottom perpendicular to the cut rock block (or core). for its installation in the initial operating position, it is necessary to pass the vertical side slit with a volume of 6-7 times more than when using the proposed device.

Claims (3)

1. Device for cutting blocks of rocks with electric discharges, containing alternating high-voltage and grounded rod electrodes located in the same plane and fastened by upper and lower holders, one of the holders being movable along the guides along the electrodes, characterized in that the lower holder is made wedge-shaped with inclined guide electrode channels, with slurry windows between these channels and with downhole supports, the exposed parts of the electrodes are made in in the form of articulated sections, and the upper holder is arranged to move along the guides along the electrodes. 2. The device according to claim 1, characterized in that the inclined guide electrode channels in the lower holder are made from two opposite sides. 3. The device according to claim 1, characterized in that the bottom-hole sections of the electrodes are made of conductive cables.

Images