RU2468205C1 - Electric pulse method of rock slabs cutting - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: electric pulse method of slabs cutting is performed by delivery of high-voltage pulses to double-electrode device with high-voltage and grounded electrodes moved along submerged slab. Before high-voltage pulses delivery to high-voltage electrode, grounded electrode is put under lower surface of elevated slab and high-voltage electrode is installed on side surface of the slab at chosen distance from grounded electrode. Then upon delivery of high-voltage pulses to high-voltage electrode as far as slab is being destroyed above grounded electrode, electrode assembly is elevated to slab height and is lowered to initial position, and operations are repeated till required cut is obtained.

EFFECT: simplifying procedure of slabs cutting and improving work efficiency.

2 dwg

Description

The invention relates to the field of processing (cutting) blocks of natural stone and non-conductive artificial materials (concrete, ceramics, etc.) by high voltage pulses and can find application in the construction industry and mining for cutting large blocks of rocks and products from artificial materials into blocks smaller sizes.

Known electric pulse method of cutting (destruction) of rocks by a moving two-rod electrode device (patent for invention RU No. 2232271, IPC 7 Е21С 37/18, ЕВВ 7/15, published on July 10, 2004, Bull. No. 19), according to which the step of moving the electrodes devices between two electrical pulses are selected from the following conditions:

moreover

where W _z is the energy stored by the source of high voltage pulses, J;

L is the interelectrode gap, mm;

W _opt - optimal fracture energy per pulse for rocks of the fortress category on the MM scale Protodyakonova, equal to 5, J;

n is the number of pulses between the high voltage and grounded electrodes.

The main disadvantages of this device are that a flushing unit is required for the removal of the destroyed rock (sludge) from the slot to be cut and that the cutting efficiency is relatively low, as when implementing the method, it is not possible to optimally take into account the specific conditions for moving the two-rod electrode device, since according to this method the device must be moved with a constantly selected step, regardless of whether the discharge is introduced into the rock or not, what is the result of exposure to the rock of electric discharges.

The second drawback is eliminated in the prototype method by which the known device for cutting rocks works (patent for invention RU No. 2393349, IPC 8 Е21С 37/18, ЕВВ 7/15, publ. 06/27/2010, Bull. No. 18). According to this method, the block to be cut is immersed in a liquid, a two-electrode device equipped with a high-voltage and grounded electrodes is installed on it, a washing liquid is supplied into the interelectrode gap with a washing unit, high voltage pulses are supplied to the high-voltage electrode, and at the same time the device is moved along the rock block into one side, to the edge of the block, and then in the opposite direction. The operation of moving the electrodes is repeated many times.

The main disadvantage of the prototype method is associated with the need for a flushing system to remove the destruction products formed between the electrodes. Moreover, the process of removing the destruction products by the prototype method is complicated by the fact that the bottom-hole ends of the electrodes substantially overlap the formed gap, preventing the pumping of the washing fluid enriched with sludge along the cut. Removing sludge from the interelectrode gap by suction (upward) further complicates the washing process and system.

The main technical result of the proposed solution is to simplify and reduce the cost of the method. It allows you to conduct the entire cutting process without the use of any flushing system, because the destruction products formed during cutting fall out of the gap down under the action of their own weight.

The specified technical result is achieved by the fact that in the electric-pulse method of cutting rock blocks by supplying high voltage pulses to a two-electrode device with a high voltage and grounded electrodes moving along a block immersed in a liquid, according to the proposed solution, before applying high voltage pulses to the high voltage electrode under the lower the surface of the raised block is supplied with a grounded electrode, and a high-voltage electrode is installed on the side surface of the block on the selected p Normal distance from the grounded electrode and then by applying high voltage pulses to the high voltage electrode, at least above the fracture rock electrode grounded electrode assembly is raised to the height of the block, is then lowered into position and the operation is repeated until a desired cut.

It is not practical to cut the blocks with this device from top to bottom by turning the device 180 ° and placing its grounded electrode on the upper surface of the block. With this option, the insulating coating of the high-voltage electrode prevents the removal of sludge from the gap to be cut due to the effect of an electric discharge on it, and even with an interelectrode gap of more than 10-15 mm, there is no guarantee that the sludge can be completely removed from the gap without supplying washing liquid to it even if there is no such obstacle.

An example of a specific implementation of the proposed method is carried out using a two-electrode device shown in figures 1 and 2. Figure 1 shows a longitudinal section of this device, vertically mounted in a tank filled with water, in which a rock block is placed, and figure 2 shows a transverse section of the device in the horizontal plane. A two-electrode device contains a high-voltage 1 and a grounded 2 electrodes, the bottom-hole ends of which are made in the form of pointed plates. The high-voltage electrode 1 is provided with an insulating (polyethylene) coating 3, to the lower end of which a dielectric holder 4 of the grounded electrode 2, having an L-shaped form, is attached. The upper end of the high-voltage electrode 1 with an insulating coating 3 is passed through the central longitudinal cuts of the lower guide 5 and the upper guide 6, through the carriage 7, moving along the upper guide 6, and also through the node of the periodic ups and downs 8 of the two-electrode device. The guides 5 and 6, as well as the dielectric holder 4 are made of fiberglass. The ends of the guides 5 and 6 are inserted into vinyl-plastic channels 9, which are mounted in a vertical position to the opposite walls of the polyethylene tank 10 opposite the intended cut. In the tank 10, a block of rock 12 is placed on the longitudinal concrete supports 11, while the supports are positioned so that the intended cut of the rock block is between these blocks. The upper end of the high voltage electrode 1 is electrically connected to a source of high voltage pulses 13, and the electrode 2 is grounded using an earth conductor 14 made of a cable braid. To ensure the development of channels of electrical discharges 15 in the rock and to prevent overlapping of the discharges along the surface of the rock block 12, the tank 10 is filled with water 16 to a level above this block.

The method is as follows. At the bottom of the tank 10, concrete supports 11 are placed, positioning them so that there is a longitudinal gap between them for the passage of the grounded electrode 2 and its dielectric holder 4. A block of rock 12 made of sandstone on lime cement is placed on these supports 11 and the tank 10 is filled with water 16 Under the lower surface of the rock block 12, a grounded electrode 2 is fed; at the same time, the high-voltage electrode 1 is installed with the bottom end on the side surface of the block 12 at a distance from the grounded electrode selected for a particular rock taking into account the parameters of the high voltage pulses. Then, high voltage pulses are supplied to the high-voltage electrode 1 from the source 13. Between the bottom-ends of the electrodes 1 and 2, electrical discharges occur directly in the rock, tearing pieces of rock (sludge) from the block 12 to a height h (Fig. 1). The height h has a variable value and if h = 0, i.e. rock detachment above the grounded electrode 2 does not occur, for example, when the energy of one electric discharge is not enough to detach the rock, the grounded electrode prevents the two-electrode device from rising upward. As the destruction of the rock above the grounded electrode 2, the node of periodic ups and downs 8 raises the two-electrode device to the height of the block 12 through the longitudinal cuts of the lower and upper guides 5 and 6. After that, the two-electrode device is lowered to the lower position using the node 8, and using the carriage 7 are moved in the direction of the slit cut in the rock block 12, and the operations are repeated until this block is cut into two parts or until a gap of a predetermined depth is formed.

Thus, the proposed method is much simpler than the existing methods, because allows cutting blocks without pumping flushing fluid, and cheaper, because does not require a flushing system. In addition, in the proposed method, the electrodes do not stand in the way of exit (removal) of sludge from the interelectrode gap, therefore, there is no energy consumption for regrinding of the sludge. So, with a distance between the high-voltage 1 and the grounded 2 electrodes of 14-16 mm, the volume of the sandstone sludge fraction more than 7 mm increased compared with the prototype method by almost 80%.

Claims (1)

An electropulse method of cutting rock blocks by supplying high voltage pulses to a two-electrode device with a high voltage and grounded electrodes moving along a block immersed in a liquid, characterized in that, before applying high voltage pulses to the high voltage electrode, a grounded electrode is brought under the lower surface of the raised block, and a high-voltage electrode is installed on the side surface of the block at a selected distance from the grounded electrode, after which, by applying pulses to high voltage to the high voltage electrode, at least above the fracture rock electrode grounded electrode assembly is raised to the height of the block, is then lowered into position and the operation is repeated until a desired cut.

Images