SU891934A1 - Blast-through device of drilling unit - Google Patents

Description

(54) DRILLING UNIT BLOWING MACHINE

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The invention relates to open pit mining, in particular, to roller cone drilling rigs for drilling large diameter wells in various rocks, mainly shallow wells in permafrost soils and rocks in the mining industry, in geological exploration, as well as wells for columnar foundations for the construction of artificial structures in the area permafrost.

A blowing device of roller cone drilling machines in open-pit mining is known, in which compressed air from a compressor goes through a purge line to a rock-breaking tool 1.

In this device, compressed air from the compressor enters through the purge line to the rock-breaking tool. The line, which includes drill rods with threaded nipple connections and a purge nozzle of roller cone bits, has a large hydraulic resistance, which necessitates the supply of relatively high pressure to compressed air from the wells. This air pressure is not less than two orders of magnitude higher than the value of the air pressure drop in the annulus of the well, necessary for the removal of drilling fines from the bottom.

Known blowing device of the drilling machine, the closest to the technical

- entities of the present invention, comprising a drill bit body, a bit of a compressor, one of which is of low pressure and high performance, and the other of high pressure and low performance, a purge line,

10 coupled to a high pressure compressor and bits, an air collector, a safety valve, and a shut-off valve. In the purge device, the high-pressure compressor machine is connected to the purge line through the valve 15, the valve with the possibility of periodic switching 2.

However, due to the fact that in this device high pressure air is supplied periodically, it cannot be used

20 to prevent drilling dust and fines from entering the bearings of the roller cone. The pressure of the low pressure air that comes to the bottom through the common line and the bit must be significantly greater, at least by one order of magnitude, in the annular space of the well required for removal from the bottom-hole fines. The presence of a distribution valve complicates the design of the device.

The above disadvantages of this blower device lead to a reduction in the resistance of the roller bit, to the associated decrease in drilling productivity, and an increase in energy costs for cleaning the well from drilling fines.

The purpose of the invention is to increase the productivity of drilling.

This goal is achieved by the fact that the blowing unit of the drilling unit is provided with an additional blowing line connected to the low-pressure compressor and to the internal cavity of the body of the drill string.

The drawing shows the blowing device of the drilling unit, General view.

The device comprises a compressor 1, an air collector 2, a safety valve 3, a high-pressure air line 4, coming to the bottom of the well through a drill bit 5 of a drill string 6, a low-pressure compressor 7, a large-section line 8 for low-pressure air. The body of the drill is part of the line 8. Compressor 1 is connected to line 4, and compressor 7 is connected to line 8. In the case of the screen there are nozzles 9 that are directly aimed at the bottom hole.

In the purge device, the drive vrashayush. One-way bits of the bits 5 dry, eats-is from the individual electric motors 10 built into the body of the projectile 10. The continuity of the lines 4 and 8, through which the air of different pressures separately enters the projectile, is ensured by the presence of a double-flow swivel 11 drilling equipment yes.

The purge device will have a similar design as applied to drilling equipment of another type, for example, a rotor, with a neura-dyush, a drilling rig, etc.

When the device operates, low pressure air from compressor 7 through line 8 enters the body of the projectile 6, flows around and cools the electric motors 10 and other mechanisms built into the projectile and goes through the nozzles 9 at high speed directly to the bottom of the well, carrying out its continuous and intensive cleaning from drill trivia.

High pressure air from compressor 1 through a separate line 4 goes to bits 5, preventing the abrasive drill bit and dust from entering the bit supports and continuously cleaning the bottom hole in the zone of contact with the cones.

The supply of low pressure purge air from the compressor through a separate line with low hydraulic resistance allows at least 2-3 times lower power and energy costs for

cleaning a large diameter borehole when drilling.

The high flow rate of purge air coming from the compressor and its high speeds in the annulus and on entering the bottom ensure effective cleaning of wells from drilling fines, eliminate its overmilling and lead to an increase in drilling speed and durability of bits. The continuous supply of high-pressure compressed air also contributes to the improvement of the durability of bits.

Claims (2)

1. Nanjing Yu. A. and others. Machines cone drilling. M., “Nedra, 1971, p. 159-163. 2. USSR author's certificate No. 631642, cl. Е 21 В 7/02, 1978 (prototype).