CN101864895A - Positive Circulation Drilling Dust Removal Technology for DTH Hammer in Cavern - Google Patents

Abstract

The invention relates to a cavern down-the-hole hammer double-wall pipe positive circulation drilling dust removal technology, which is specially used for the hole dust removal method of the normal down-the-hole hammer + double-wall pipe combination positive circulation drilling. The dust removal part is realized by three parts: the water supply box, the double-wall pipe, and the water spray conversion joint; compared with other cavern grouting hole drilling dust removal methods, this dust removal method has a simple and reliable structure, good dust removal effect, and does not affect the general submersible. Hole hammer impacts drilling efficiency. When the hammer head of the down-the-hole hammer starts to impact and drill, water with a certain pressure is sent into the annular gap of the double-wall pipe through the water box, and the water enters the water spray conversion joint from the annular gap, and the pressure water is arranged in the spray from the circumference. The small hole on the water conversion joint sprays out to form a water mist area, and the exhaust gas carries rock powder and mixes in the water mist area, and the multiphase flow of water, gas and rock slag formed flows along the annular gap between the double-wall pipe and the hole wall. Out of the discharge hole, it realizes normal DTH hammer positive circulation rock drilling wet dust removal.

Description

Positive Circulation Drilling Dust Removal Technology for DTH Hammer in Cavern

technical field

The invention relates to a cavern down-the-hole hammer double-wall pipe positive circulation drilling dust removal technology, which can achieve the effect of dust removal in the hole without affecting the rock drilling efficiency. It can be applied to the construction of grouting holes in caverns, geological drilling, and mining to reduce or eliminate the hazards of dust to human health and machine performance during drilling.

Background technique

The traditional method of down-the-hole hammer is positive circulation drilling. When drilling, the airflow discharged from the hole carries slag chips and is ejected from the orifice. The dust is diffuse, endangering the health of workers, polluting the construction environment, and affecting the service life of the machine. Therefore, the choice of dust removal method is particularly important.

At present, the dust removal technology methods in the drilling process of pneumatic down-the-hole hammer generally have the following types:

1. Through-type down-the-hole hammer reverse circulation drilling center slag collection and dust removal

The reverse circulation through-type pneumatic DTH hammer is drilled, and the central slag is removed by dust removal equipment (such as cyclone dust collector, dust drop box, etc.), which increases the dust removal equipment and correspondingly increases the construction cost; the through-type DTH hammer piston center The diameter of the designed through-hole is larger, and the piston wall becomes thinner, which reduces the impact energy and energy transfer efficiency of the down-the-hole hammer, and the drilling efficiency decreases significantly. In addition, the high-frequency impact can easily cause the piston to break and cause a drilling accident.

2. Positive circulation DTH hammer drilling foam dust removal

Compressed air and pressure water (including foam agent) are mixed outside the hole and introduced into the hole to drive the down-the-hole hammer. Generally, lubricants and foaming agents need to be added to the water, which increases the construction cost; the foaming agent injected with compressed air will obviously reduce the rock drilling efficiency of the down-the-hole hammer.

3. Orifice impactor rock drilling wet dust removal

At present, rock drilling rigs at home and abroad generally adopt impactor wet rock drilling technology, which uses the impactor to discharge waste gas and mix it with water, and then introduces water and waste gas into the drill bit through the drill rod (single-layer drill pipe) to achieve cooling of the drill bit, slag removal and dust removal. Purpose. When the hole depth increases, the energy transfer efficiency decreases significantly, which affects the rock drilling speed and is suitable for shallow hole drilling.

4. Dust capture and dust removal at the orifice

For downward drilling, it is also a commonly used dust removal technology to use orifice dust collectors to collect dust and dust removal equipment (such as cyclone dust collectors, dust drop boxes, etc.) to remove dust. In the construction of grouting holes in caverns, it is necessary to carry out drilling operations within the 360° range of the caverns, and it is not easy to install the dust catcher on the top of the cavern.

Contents of the invention

The present invention is made up of gyrator (top driving power head or turntable), water delivery box, double-wall pipe, water spray conversion joint, common down-the-hole hammer, drill bit. The water delivery box is connected with the gyrator by bolts, it can be under the gyrator, or it can be designed above the gyrator according to the structural characteristics of the gyrator, and the water spray conversion joint is connected with a common down-the-hole hammer and a double-wall pipe. The compressed air is sent to the down-the-hole hammer through the central channel of the double-wall pipe to drive the down-the-hole hammer to drill rock. The exhaust gas is discharged through the exhaust hole of the drill bit, flushes the bottom of the hole, cools the drill bit, and carries cuttings back along the annular gap between the hole wall and the down-the-hole hammer.

The water at a certain pressure is sent into the annular gap between the inner pipe and the outer pipe of the double-arm pipe through the water supply box, and the water is sent to the water spray conversion joint connecting the down-the-hole hammer and the double-arm pipe. Joint 6 and joint 7 are welded together, joint 6 and the double-wall pipe outer pipe are connected by taper thread, one end of joint 7 is connected by taper thread to the joint of the down-the-hole hammer, and the other end is inserted into the double-wall pipe inner pipe. Prevent compressed gas from entering the annular gap of the double-wall pipe, and prevent water of a certain pressure from entering the central channel of the double-wall pipe. A sealing ring is added to the double-wall pipe to ensure the reliability of the seal; there are many small holes for spraying water mist on the joint 6 , the small holes are circumferentially arranged on the joint 6, and the diameter is no more than 2-4mm; a cross water mist area can be formed, and the exhaust gas carries rock dust and mixes in the water mist area, forming a multiphase flow of water, gas and rock slag along the double The annular gap between the wall pipe and the hole wall discharges out of the hole. It realizes the positive cycle drilling wet dust removal of ordinary down-the-hole hammer, and the drilling efficiency is not limited by the hole depth.

Description of drawings

Fig. 1 Schematic diagram of DTH hammer double-wall pipe positive circulation drilling system

Figure 2 Structural diagram of the water spray conversion joint

Detailed ways

This design consists of the following parts:

Rotator 1, water supply box 2, double wall pipe 3, joint 6, joint 7, down-the-hole hammer 8, drill bit 9

When working, the compressed air is transmitted to the down-the-hole hammer (8) through the central channel (5) of the double-wall pipe, so that the gas drives the piston to reciprocate, and impacts the drill bit (9) for rock drilling; the exhaust gas is discharged through the exhaust hole of the drill bit (9) , flush the bottom of the hole, cool the drill bit (9), carry cuttings back along the gap between the hole wall and the down-the-hole hammer (8), and meet the annular gap between the water box (2) and the double-wall pipe (3) (4) In the water mist area sprayed by the conversion joint (6) (7), the exhaust gas carries the rock dust and mixes in the water mist area, and the multiphase flow of water, gas and rock slag formed runs along the double-walled pipe and the hole wall. The annular gap discharges out of the hole, realizing the positive circulation of ordinary down-the-hole hammer drilling wet dust removal.

Claims (2)

1. positive-circulation drilling and dedusting technique of chamber down-hole hammer and double-wall pipe, when it is characterized in that work, when gyrator 1 (top-drive or rotating disk) drove the 3 direct circulation rotary drillings of down-the-hole hammer double-wall pipe, the common down-the-hole of compressed air-driven was hammered 9 rock drilling of 8 drill hammers into shape; The waste gas cutting carring of discharging directly runs into the water smoke district along returning on the gap between hole wall and the down-the-hole hammer 8, carries out wet drilling dedusting in the hole.

2. dedusting technology according to claim 1, the water that it is characterized in that certain pressure is sent water into the interior pipe 5 of both arms pipe and the annular gap 4 between the outer tube by sending water box 2, enter in the water spray conversion joint of forming by joint 6 and joint 7 by annular gap 4, joint 6 uses taper thread to be connected with double-wall pipe 3 outer tubes, one end of joint 7 uses taper thread to be connected with down-the-hole hammer 8 back joints, pipe is pegged graft in the other end and the double-wall pipe 3, in order to prevent that Compressed Gas from entering double-wall pipe annular gap 4, prevent that simultaneously the water of certain pressure from entering the interior pipe 5 of double-wall pipe, additional encryption seal 10 on double-wall pipe guarantees the reliability that seals; The aperture 11 that many water sprays are arranged on the joint 6, aperture 11 circumferential array are on joint 6, and diameter is no more than 2-4mm; Can form the water smoke district of intersection, waste gas carries rock dust to be mixed in the water smoke district, outside the annular gap tap of the multiphase flow of the water of formation, gas and rock slag between double-wall pipe 3 and hole wall.Realize common down-the-hole hammer direct circulation rock drilling wet dust removal.

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