RU2663984C2 - Method of construction and repair of ventilation facilities in coal and shale mines - Google Patents

Abstract

FIELD: mining industry.SUBSTANCE: invention relates to the mining industry, in particular to the repair of ventilation facilities in underground workings of coal and shale mines. Method of repairing a ventilating insulating structure in coal and shale mines consists in that the materials for restoring the airtightness of the ventilating structure are applied layer by layer. In this case, each layer consists of a single material, and the materials from which the layers are made, different in composition: mineral; polyurethane foams, differ in properties: curing speed and subsequent air tightness; curing speed and subsequent water resistance.EFFECT: technical result consists in an effective sealing of the insulating bridge in coal and shale mines located in the second limiting state.1 cl, 2 dwg

Description

The present invention relates to the mining industry, to the construction and repair of ventilation structures in underground workings of coal and shale mines.

Underground mining in the coal mining industry employs high-performance mines and sinking faces. This is due to the economic task of producing the maximum amount of coal per unit time, which significantly reduces the cost of production and allows the coal enterprise to operate profitably. To ensure stable and uninterrupted operation of high-performance coal treatment faces, it is necessary to prepare mine workings in advance. This is carried out by organizing the work of high-speed sinking faces, which allow you to build workings, depending on the cross-sectional area and the roof support used, with a capacity of up to 500 lm. for 1 month. To ensure the operation of high-performance treatment faces and high-speed headings, timely construction of ventilation structures (crossings, insulating jumpers, ventilation jumpers) is required to regulate the air movement in the mine workings, isolation of the worked space. In this case, the jumpers erected in the mine can be divided into two categories according to the bearing capacity: bearing insulating jumpers; self-supporting ventilation jumpers. Bearing insulating jumpers - this is a structure with calculated strength for external impact: the effect of the blast wave - explosion-proof insulating jumpers; exposure to water pressure - waterproof insulating jumpers. Self-supporting ventilation lintels are structures used to regulate the direction of air movement in mine workings, for example: a temporary jumper is deaf, a temporary jumper with a passage for people, a jumper is blind, a jumper with a passage for people. (Order of Rostekhnadzor dated November 28, 2014 N 530 "On approval of Federal norms and rules in the field of industrial safety" Instructions for the isolation of unused mine workings and mined spaces in coal mines ").

The main requirements for the design of supporting insulating jumpers are: preservation of the strength and stability of the structure under the influence of the pressure of the enclosing rocks in the mine, where this structure was erected; restoration of tightness (air tightness or water tightness) during periodic repairs (maintaining tightness) during the entire life of the insulating jumper.

From the existing level of engineering and technology in the construction industry, various methods and materials for repairing monolithic or precast concrete structures to restore their tightness are known. In patent RU 2187652, a technology for layer-by-layer spraying of polyurethane foam foams obtained from 2 components by mixing in a “gun” sprayer is proposed. This technology allows you to build effective sealed ventilation bridges in a short period of time, to repair ventilation structures to reduce air loss (leakage) through the structure of the ventilation bridge and the rock mass adjacent to the ventilation bridge. However, the method described in patent RU 2187652 has a serious drawback. The materials used by this technology, polyurethane foam PPU: PPU-17N-1, PPU350-N, Izolan-6, Vilan-405 and others are synthetic polymeric materials in their composition and without special, additional technological operations associated with the protection of polyurethane foam by applying effective heat-insulating and fire-retardant coatings can not be applied in coal and shale mines according to fire safety requirements. According to the requirements of paragraph 474 of the Order of Rostekhnadzor No. 550 dated November 15, 2013, "Safety Rules in Coal Mines," the substances and materials used in mines must be classified as slow-burning and non-combustible in the combustibility category. Materials for the construction and repair of ventilation structures specified in patent RU 2187652, are classified as combustible according to the degree of fire hazard.

The technical problem to be solved by the claimed invention is directed is a method for producing an effective repair of a bearing ventilation structure in a second limiting state.

The problem is solved by layering on the surface of the supporting ventilation structure and adjacent surfaces of the mine workings of various in composition materials: mineral; polyurethane foams to restore the tightness of the structure.

SUMMARY OF THE INVENTION A major ventilation insulating structure is being repaired (to restore its tightness) by applying layers of various materials. At the same time, each separate layer of the material applied to the surface of the ventilation structure accentuates performs a specific task of sealing the structure, and in the complex, the resulting multilayer coating allows for better sealing of the ventilation structure with a general reduction in the cost of materials used for processing.

The technical result. When repairing an insulating jumper to restore or maintain its tightness by the method of layer-by-layer application of materials, it becomes possible to combine in one unit volume of the applied sealing coating, but in different layers of this unit volume, materials having a speed that varies many times: hardening and subsequent air tightness; hardening and subsequent waterproofing; hardening and curing. This allows you to effectively carry out the sealing of the insulating jumper, located in the second limit state. In this case, repairs are carried out when water from cracks in the body of the structure for the watertight insulating jumper enters, when the air-gas mixture flows from the waste space through cracks in the body of the structure for the explosion-proof ventilation insulating jumper.

The proposed method was used for preventive maintenance of a ventilation insulating bridge at one of the coal enterprises in Kuzbass.

толщиной 3 мм, пенополиуретан становится воздухонепроницаемым, но податливым к механическим воздействиям через 15 минут после нанесения. В результате дренаж воздуха прекратился полностью. Для защиты слоя пенополиуретана (4) на него несли слой (3) из герметизирующей композиции «Негорючая крепь».Under the influence of significant deformations of the enclosing rocks, cracks formed in the design of the lintel figure No. 1. As a result, air from the waste space began to flow into the exploited mine workings. The surface of the lintel Figure No. 2 and the adjacent surfaces of the mine workings were treated with the non-combustible lining mineral sealing compound (3) TU 5772-004-50576573-2014. Within 3 hours after application, the coating (3) hardened and became airtight and moisture resistant. After the work on the device covering the lintel for its repair with the material, the non-combustible lining sealant composition, air drainage from the exhausted space through the lintel was significantly reduced, but continued along the cracks in which the material did not have time to harden until the air-gas mixture pressure from the exhausted space was completely blew it out of the crack. To completely eliminate air drainage through the remaining cracks, a layer of polyurethane foam (4) was applied to the jumper from an autonomous two-component brand system

3 mm thick, polyurethane foam becomes airtight, but malleable to mechanical stress 15 minutes after application. As a result, air drainage stopped completely. To protect the polyurethane foam layer (4), a layer (3) of the non-combustible lining sealant composition was carried on it.

The scheme of layer-by-layer erection during the construction of the ventilation bridge and layer-by-layer application of materials during the repair of the isolation bridge is shown in Fig. No. 1; fig. No. 2.

A brief description of the drawings.

Figure 1 shows a cross section of a ventilation insulating jumper with a layered coating to maintain tightness. Figure No. 2 shows View A. The multilayer coating of the ventilation insulating bridge for its repair and restoration of tightness:

1. Concrete "body" of the jumper;

2. Fixed formwork made of slag concrete stones;

3. The sealing composition "Non-combustible lining" TU 5772-004-50576573-2014;

4. A layer of polyurethane foam with a thickness of 3 mm from an autonomous two-component system of the brand

5. Cracks in cinder-stones and concrete of the “body” of the lintel filled with the non-combustible lining sealant TU 5772-004-50576573-2014.

Literature.

1. Order of Rostekhnadzor dated November 28, 2014 N 530 "On approval of Federal norms and rules in the field of industrial safety" Instructions for the isolation of unused mine workings and mined spaces in coal mines ".

2. RU 2187652.

3. Order of Rostekhnadzor No. 550 dated November 15, 2013 “Safety Rules in Coal Mines”.

Claims (1)

A method of repairing an insulating ventilation structure in coal and shale mines, characterized in that the materials for restoring the air tightness of the ventilation structure are applied in layers, each layer consisting of one material, and the materials of which the layers are made, different in composition: mineral; polyurethane foams, differ in properties: hardening speed and subsequent air tightness; hardening speed and subsequent waterproofing.

Images