Soil crushing device

Abstract

FIELD: mining industry.SUBSTANCE: device for crushing soils includes a cylindrical working chamber with loading and unloading windows for placing soil samples in it, side disks, a central axial rod, cables made of abrasion-resistant, low-stretch materials secured to the side disks with bearing-type hinges, and a mechanical rotational energy drive. Soil samples are loaded through the top loading windows and positioned between the cables and the central axial rod. By rotating one or two side disks from the drive, the cable system is twisted and moved relative to the central axial rod, which leads to the cables gripping the soil samples, crushing and abrading them.EFFECT: increased productivity of soil crushing is ensured, and the forces required for crushing are reduced through the use of minimal tensile resistance of soils.1 cl, 6 dwg

Description

[0001] The invention relates to mining and is intended for crushing soils and can be used in the mining industry for enrichment and other preparatory processes.

[0002] Soil crushing is the process of reducing the size of pieces (grains) of minerals by breaking them up using external forces that overcome the internal cohesive forces that bind the particles of solid matter together. [Crushing, grinding and screening of minerals. 4th ed. / Perov V.A., Andreev E.E., Bilenko L.F. - Moscow: Nedra. 1990. - p. 74].

[0003] Rocks exhibit the highest resistance values ​​under compression, less under bending and minimal under tension, however, modern enrichment methods are based primarily on crushing and impact force with the addition of abrasive and bending effects [Gorlov, I. V. Analysis of the process of crushing weak rocks [Text] / I. V. Gorlov, P. E. Mitusov., A. M. Belyaev / / Coal. - Moscow. - 2022. - No. 6 (1155). - P. 44-47.].

[0004] Jaw and cone crushers are widely used in production and beneficiation. The first type of crusher operates by crushing and grinding the material between two plates (cheeks). The drive mechanism causes the movable jaw to roll relative to the stationary one, which leads to crushing and, in the case of complex rolling, abrasion of the material loaded into the crushing chamber. The second type of crushing is based on the continuous movement of the movable cone from an eccentric shaft inside the stationary one, where, as they approach and move away again, the loaded rock is destroyed by crushing and bending [Malich, N. G. Analysis and Development Prospects of Domestic Machines for Crushing Hard Materials [Text] / N. G. Malich, V. S. Blokhin, A. O. Degtyarev / / Mining Information and Analytical Bulletin. - Moscow. – 2007. – No. 21. – P. 365–380].

[0005] Due to a certain level of variability in the mechanical properties of rock during crushing using the above mechanisms, sharp fluctuations in the operating mode may occur, which causes moments of underload and overload of the crushing path and reduces productivity with an increase in energy consumption [Khopunov, E. A. Energy and power factors of selective destruction of ores [Text] / E. A. Khopunov / / News of universities. Mining journal. - Ekaterinburg - 2020. - No. 1. - P. 79-88. Khurelchuluun, I. Application of visiometric analysis of the granulometric composition of ore for automated control of the crushing process [Text] / I. Khurelchuluun [et al.] / / Ores and metals. - Moscow. - 2019. - No. 1. - P. 67-73.].

[0006] A known design of a jaw crusher [Patent RU No. 2365411, IPC B02C 1 / 04, published 08 / 27 / 2009] includes a welded frame made integral with fixed and movable jaws with a lining in the form of replaceable crushing plates, a shaft mounted in bearings with an eccentric and a connecting rod head mounted on the eccentric, V-belt drive pulleys, the linings of the fixed and movable jaws have cavities on the rear side for unloading products, and the linings of both jaws are provided with through holes for continuous removal of clay mass from the working chamber into the cavities, preventing its accumulation in the working area of ​​the crusher.

[0007] A known rotary crusher comprises a housing with a rotor placed in it with impact elements fixed to it, a grate fixed to the housing under the rotor, hingedly fixed to the housing and spring-loaded to it by spiral springs [Volkov V.T. et al. Mechanization and automation in the industry of non-metallic building materials. Moscow, State Scientific Institution, 1963, pp. 130-132, Fig. 25].

[0008] Vertical hammer crushers with an upper or lower drive arrangement are known from the prior art (for example, see patents SU 837402, IPC: B02C 13 / 16, published on 15.06.1981, RU 2021854, IPC: B02C 13 / 16, published on 30.10.1994, EP 2415526, IPC: B02C 13 / 16, 08.02.2012), containing a cylindrical body with loading and unloading pipes and a rotor with pivotally mounted hammers. The rotor shaft is secured in self-aligning rolling bearings located in the upper and lower housing covers and designed to operate with significant skew of the inner ring relative to the outer ring, caused by misalignment of the mounting seats or deflection of the shaft under load.

[0009] A cone eccentric crusher is known [US Patent No. 3315901 class 241-211 from 03 / 15 / 65], which uses a crushing method that includes setting an optimal discharge gap, metered loading of ore into the crushing cavity and crushing it.

[0010] A jaw crusher is known, comprising a housing, fixed and movable jaws, an eccentric drive transmitting motion to the movable jaw through a connecting rod and a flexible plate element, one end of which is rigidly clamped in the body of the connecting rod, characterized in that the other end of the flexible plate element is rigidly fixed in the housing of the crusher (patent RU 52739, IPC: B02C 1 / 04, published 04 / 27 / 2006).

[0011] A self-grinding mill containing a rotating drum with end bottoms, a discharge grate, hollow loading and unloading journals and lining plates with lifter elements, a drive is adopted as the closest prototype to the claimed device in terms of the presence of similar design features. Moreover, in order to increase productivity and reduce energy costs by reducing the load on the drive, it is equipped with an armor belt with cells fixed above the zone of occurrence of the segregation core, and electromagnetic exciters installed in the cells of the armor belt (a.s. SU 1514401 A1, IPC BO2C 19 / 11, published 15.10.1989).

[0012] The disadvantage of these technologies and devices is their operating principle, which relies on soil compression—the greatest strength characteristic, the compressive strength—while the tensile strength of soils is an order of magnitude lower. Soil crushing methods based on compression and impact with working tools require significant mechanical force to break them. Therefore, it is more effective to break soils by stretching them rather than compressing them.

[0013] The objective of the invention is to create a device for crushing soils by stretching them.

[0014] The technical result of the proposed invention consists in increasing the productivity of soil crushing and reducing the forces required for crushing through the use of minimal tensile resistance of soils.

[0015] The technical result is achieved by the fact that cables are stretched along the device, participating in a twisting movement towards the central axial rod of the working chamber, thereby clamping the soil and transferring a concentrated load to its surface - destruction occurs by stretching.

[0016] The device for crushing soils is illustrated by the drawings, where Fig. 1 is a general view of the device, Fig. 2 is a top view, Fig. 3 is a bottom view, Fig. 4 is a section A and B, Fig. 5 is a section of the device in the initial phase of operation, and Fig. 6 is a section of the device in the soil crushing phase.

[0017] The device includes a cylindrical working chamber 1 for placing soil samples in it, side disks 2, a central axial rod 3, cables 4, a mechanical rotational energy drive 5, loading windows 6 and unloading windows 7.

[0018] The device utilizes three cables (4) made of abrasion-resistant, low-stretch materials, such as special steel alloys or polymers. The cables (4) are secured to two side disks with bearing-type hinges, which allow the cable (4) to rotate but limit its movement within the working chamber. Soil sample fracture by tensile stress occurs due to the splitting and abrasion of the cables (4) twisting together.

[0019] An external source of mechanical energy rotates the side disks 2 of the device. Axial rotation of one disk 2 (or both in opposite directions) causes the tilt and movement of the cables 4 pivotally attached to it. Thus, the central portion of the cable 4 moves from a lateral position inside the working chamber 1 toward the center of the device and transmits force to the soil samples. The ends of the cables 4, secured to the disks 2, move only in the plane of rotation. The magnitude of the force transmitted to the samples can be determined geometrically from the equation of stable equilibrium, for example, for a load suspended on an inextensible cable. The device can be configured with cables 4 of a diameter such that, during operation, the force required to split the soil samples will not cause significant stretching and unwinding of these cables 4.

[0020] Soil samples are destroyed by clamping them with cables 4, pressing them against the central axial rod 3, and also by abrasion and grinding between themselves and the elements of the working chamber 1. The expected process of destruction is predominantly of a stretching nature due to the application of a destructive normal load pointwise or linearly, depending on the size of the soil sample and the degree of its coverage by cables 4, as well as the presence of a torque from the centrally directed movement of the middle part of cables 4.

[0021] The movement of the side disks 2 has a pendulum-like nature with a duration of one whole period (one revolution around the axis) or less, depending on the geometric characteristics of the soil samples, the required twisting force of the cables and the breaking of the samples.

[0022] It is permissible to design the device in which both side disks 2 rotate, to ensure the twisting of the cables 4, they rotate in different directions, or such a design of the device in which one of the side disks 2 is fixed motionless, and the other side disk 2 rotates, producing the twisting of the cables 4.

[0023] The drive unit 5 is a mechanism that transmits energy from the engine or manual action through the handle to the working elements for soil crushing. In the design described below, the drive performs reciprocating movements.

[0024] The device operates as follows.

[0025] At the first stage of the grinding process, the disks 2 are located at the initial zero point, the rotation angle is 0º, the cables 4 are parallel to the central axis of rotation of the disks 2, their tension is minimal.

[0026] At the second stage, soil samples are placed through the upper loading windows 6 and are located between the cables 4 and the central axial rod 3.

[0027] In the third stage, by rotating one or both side disks 2, the cable system 4 is twisted and moved relative to the central axial rod 3, increasing their tension. The torque is converted into a concentrated load applied to the soil samples, either pointwise or linearly, creating compression and subsequent splitting of the samples into two or more pieces. The samples are also abraded by the cables 4 and by each other and the central axial rod 3.

[0028] The fourth stage is the rotation of one or two side disks 2 back to the zero position, the unclamping of the split sample by cables 4 and the unloading of the resulting ground material under the action of gravity into the lower unloading windows 7.

[0029] The following parameters can be recorded to quantitatively evaluate the device’s performance:

[0030] – time spent on one grinding cycle (from loading to unloading the product);

[0031] - the amount of mechanical energy required to rotate one or two side disks, which allows us to judge the force required to destroy the soil;

[0032] - the quantity, linear dimensions and area of ​​the newly formed surface (hypotheses of P. Rittinger, Kirpichev and Bond) of the obtained soil fragments after the grinding cycle.

[0033] Test example:

[0034] Laboratory tests were conducted on soil samples from the Vendian Padunskaya Formation (V2pd), composed of medium- and coarse-grained red sandstones. Prior to the main tests, all samples were classified by mass and visual shape to minimize errors associated with the heterogeneity of the source material. With a sample size of five, the average size of the irregularly shaped samples was 80 x 60 mm.

[0035] Selected samples were placed into the working chamber 1 through the upper loading ports 6 and positioned between the central axial rod 3 and the cables 4. One of the side disks 2 was set in motion, causing the cables 4 to move and press the soil samples against the central axial rod 3. A concentrated tensile force applied to the surface of the samples resulted in their destruction. The resulting ground material was discharged through the lower discharge ports 7. The time required for one destruction cycle averaged 10-15 seconds.

[0036] Based on the results of the tests, the quantity and linear dimensions of the obtained fragments were measured - the average size was 15×20 mm, the quantity was 13 pieces, the yield of smaller samples and finely dispersed abrasion products was not taken into account.

[0037] The force applied to the handle was determined using an electronic spring balance. Thus, breaking a sandstone sample with a tensile strength of 0.25 MPa required a force of 100 N. For comparison, according to classical theory, breaking the same sample by compression would require a force 10-12 times greater than the current force (based on the compressive to tensile strength ratio for this rock of ≈12:1). This serves as indirect, yet convincing, confirmation of the potential energy efficiency advantage.

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