SU829931A1 - Rock-breaking method and apparatus - Google Patents

Description

childbirth, reduced productivity and increased energy intensity of destruction.

The closest in technical essence and the achieved result to the invention is a method of destruction of rocks by electrodynamic impact on the rock, which is carried out by the building to destroy rocks, including a frame with electrodes, which are installed with the possibility of longitudinal and transverse movement 23.

However, the effectiveness of the destruction. the rocks remain low, because there are often rocks of approximately the same electrical resistance between the electrodes and then, when a pulse of electrical energy is applied, it is released on several pairs of electrodes, which leads to its long-term release (spreading) without electrodynamic destruction of the rock. The destruction efficiency decreases sharply, the energy intensity and the cost of destruction increase.

The purpose of the invention is to increase the efficiency of destruction due to the preliminary weakening of the rock.

This goal is achieved by the fact that the rock is exposed to infrared radiation, the location and size of the cracks are determined, and electrodynamic action is carried out in the places of the greatest fracture. The device for destroying rocks is equipped with infrared heaters and acoustic sensors for controlling fatigue, with the heaters mounted on the frame, and a screen is mounted between the electrodes and heaters.

On; FIG. 1 shows the proposed device, side view; in fig. 2 the same, top view; in fig. 3 is a section A-A in FIG. 2

A device for carrying out the method of destroying rocks has a carrier frame 1 and infrared heaters 2 located thereon (see Fig. 1-3), screen 3 is placed between the last row of heaters 2 and electrodes 4, which are installed with the possibility of longitudinal and transverse displacement relative to the cancer 1. Through the bushing insulator 5, a cable is supplied to supply the electrodes 4, on which acoustic conrol sensors are installed, the whole node is connected to the dielectric slide 7 with transverse relative to ram 1 E, which in turn is disposed on dielectric guide yuishh. 8 with longitudinal cuts / fixed on supporting insulators -9. At the intersection of the device between the heaters 2 there are wheels 10 that hold frame 1 with heaters 2 at a given distance from the surface of the rock. The destroyed mountainous rock is immediately selected by a removable bucket 11, which is fixed to the frame 1.

The device works as follows.

The device is installed on the rock surface, the heaters 2 are connected to the network, they are brought to a predetermined temperature, and after two minutes of heating (on average) the rock surface begins to move it in the direction of destruction at a rate that allows irradiating new sections of the rock for at least two minutes. Electrodes 4 with acoustic sensors 6 have the possibility of longitudinal displacement relative to frame 1, which makes it possible to determine the greatest fracture of the rock on the irradiated surface. The electrodes 4 are stopped and an impulse of electric current is applied to them with a breakdown voltage sufficient to polarize mechanical defects and to break the channel at a certain depth. The pulsed electrical energy released in the channel dynamically separates the destroyed rock from the massif, which is loaded into the ladle 11. A screen 3 installed between the heaters 2 and the electrodes 4 protects the heaters from mechanical impacts of the rock destroyed by electrical impulses. The movement speed of the device is selected in accordance with the predetermined breaking capacity, and the need to heat the rock for a certain time is taken into account in order to create a certain thickness of the heated layer. Thus, the method of rock destruction includes the following operations performed in the specified sequence: 1 preliminary impact on the rock by infrared radiation, 2 - determining the location and amount of friction formed during the 1st operation, 3 - electrodynamic effect on the rock to separate it from array, and this effect is carried out in areas of greatest fracture.

In this case the following Physical essence of destruction takes place.

Claims (2)

As a result of local heating over the area and at a certain depth, depending on the thermal conductivity of the rock, compressive thermal stresses occur with a maximum around the perimeter of the heating area and tensile at the contact of the heated rock at a certain depth with the heated, and the tensile stress vector is directed perpendicularly heated rock surface. The resulting thermal stresses reach the corresponding ultimate strength of the rock, cracks of different widths appear, including rocks directed deep into and forming pinpoints, cavities are formed due to evaporation and melting of low-temperature inclusions. All these violations lead to the loss of strength of the rock, but the separation of the destroyed rock from the massif does not occur due to the friction of the occurring detachments along the boundaries of cracks. The greatest accumulation of cracks is detected with the longitudinal movement of the electrodes with sensors by the smallest value of the velocity of the continuous acoustic waves. When a pulsed electric field is applied to the electrodes and the .jHeKOTOpoft is created, the intensity of the field of cracks and other mechanical defects becomes polarized and the resulting charges accumulate during the pulsed electric discharge on these defects and create their own potential, the value of which can be 80- 90% / of the value of the superimposed gender. The breakdown of defects does not occur over the rock surface, where the crack width is greatest, but at a certain depth, which can reach up to t / 3, where t is the distance between the genera. The accumulated charges create a field sufficient for breaking a narrowed crack. Breakdown of cracks and friend defects on. depth leads to a decrease in electrical resistance or loss of electrical strength of the rock volume, which becomes less than the surface resistance. This creates a benefit. conditions for the development of a channel of breakdown at a specified depth with the use of pulsed electrical energy in it and the dynamic separation of the rock previously weakened by infrared radiation from the massif. Since the process of heating and determining the location and size of cracks is carried out over a large area continuously, and electric current pulses are applied at a frequency of up to 1 Hz, the destruction process is almost continuous, which creates objective conditions for its use in secondary technology. Claim 1. Method of rock destruction by electrodynamic impact on the rock, characterized in that, in order to increase the efficiency of destruction due to preliminary attenuation of the rock, the rock is affected by infrared radiation, the location and size of the cracks are determined, and the electrodynamic effect They are in the places of the most fractured. 2. Device for implementation. The method according to claim 1, comprising a frame with electrodes that are installed with the possibility of longitudinal and transverse movement, characterized in that it is equipped with infrared heaters and acoustic sensors controlling the fracture, the heaters are mounted on the real, and between the electrodes and heaters are mounted screen. Sources of information taken into account during the examination 1. USSR author's certificate No. 341944, cl. B 21 C 37/18, 1970. 2. Authors' certificate of the USSR E 21 C 37/18, 1973. -777g yxxxg vy.y / yx yxxA y / y // A -, // J // //.|Ги jj ji j. И. jj j. j .. ..ifji. ..u.i j i.t (l; УV / Л Sf;: And / i. 7 fwj g w