GB2197595A

GB2197595A - Fluid supply apparatus for drilling device

Info

Publication number: GB2197595A
Application number: GB08626737A
Authority: GB
Inventors: Eric Arthur Jackson
Original assignee: PERARD TORQUE TENSION Ltd
Current assignee: PERARD TORQUE TENSION Ltd
Priority date: 1986-11-08
Filing date: 1986-11-08
Publication date: 1988-05-25
Anticipated expiration: 2006-11-08
Also published as: ZA872336B; GB2197595B; GB8626737D0

Abstract

The apparatus comprises an air line (2) a water line (11) and a mixing head (6), which provides a mist to suppress dust. A high pressure air supply, but a low pressure water supply are provided. A piston/cylinder assembly (24) has a water dispensing chamber (26') connected to a water reservoir (7). The piston is double-acting and is connected in the air supply. Air pressure on one side of the piston (25) dispenses water from the chamber and air pressure on the opposite side of the piston draws water into the chamber. <IMAGE>

Description

FLUID SUPPLY APPARATUS In mining operations, drilled holes are frequently flushed out with either water or air, to remove accumulated debris. In some mining operation5, for example in particular those involving rocks such as gypsum where water flushing is not readily usable, dust created by the drilling can be a hazard. U.K. Patent Application No. 8529773 (published as 2168266) discloses an air/water mixing head having a nozzle for forming a fine mist of water in air in order to control such dust.

This nozzle is supplied from a pressurised water container, but such containers are undesirable because of their bulk and because frequent and inconvenient testing procedures to ensure safety are necessary, resulting in lost production time.

The present invention seeks to provide an improved apparatus for supplying air and water to such a mixing head.

From one aspect, the present invention provides fluid supply apparatus for use with a drilling device and comprising an air line having an inlet for receiving air under pressure and an outlet for supplying an air/water mixing head for producing a mist, a water line having an inlet for receiving water and an outlet for supplying the mixing head, and impulsion means in the water line for pressurising the water delivered to the water outlet, the impulsion means having pressurising means connected to the air line whereby the pressurised air imparts pressure to the water supply.

The apparatus may form part of apparatus for supplying air and water to a mixing head adapted to form a water/air mist for controlling dust created by a drilling device, the apparatus comprising a source of water, feed detection means to detect whether the drill feed of the device is operating, water supply control means to allow tne supply of water t= the mixing head when the drill is fed, rotation detection means to detect whether the drill is rotating, and air supply control means to allow tne supply of air to the mixing head when the drill is rotating.

Advantageously, the apparatus comprises retraction detector means wnich detects retraction of the drill rod, and impulsion control means which causes tne impulsion means to fill with water, under the action of the compressed air, when the drill rod is retracted.

Furthermore, it is convenient if the water supply control means is adapted to shut off the supply of water to the mixing head when the drill is retracted.

Thus, in a drilling cycle, forward movement of the drill rod is detected, whereupon water and air are supplied to the mixing head. When the drill rod is retracted from the hole being drilled, then the supply of water to the mixing head is shut off, and the impulsion means fills up with water ready for the next cycle.

In a particularly preferred emoodiment, the apparatus also comprises drill penetration speed detector means and tne water supply control means is adapted to reduce the supply of water to the mixing head when the drill penetration speed falls. Thus, when the drill is penetrating only slowly, water is saved and the problems which may otherwise occur when a large volume of water is continued to be supplied may be obviated. Suitably, the drill penetration speed detector means comprises a differential valve located in the hydraulic circuit controlling the drill rotation.

So that the invention may be more readily understood, a preferred embodiment will now be described by way of example and with reference to the accompanying drawings in which Figure 1 is a schematic view of an apparatus in accordance with the invention; Figure 2 is a side elevation of a dispenser forming part of the apparatus of Figure 1; and Figure 3 is a longitudinal section of a differentiating valve forming part of the apparatus of Figure 1.

Referring first to Figure 1, the apparatus comprises an air intake 1 for connection to a compressed air supply. The air intake 1 is connected to a line 2 which leads to a first servo valve 3. A further line 4 leads from the servo valve 3 to an air inlet 5 on a mixing head 6, which is adapted to create a fine water/air mist. The head 6 may be as described in U.K. Patent Application No.

8529773, and will not be described in detail here.

A water storage tank 7 is provided with a filler hole 8 and a breather vent 9 and supplies water via a manually operable stop valve 10 to a line 11 having two successive one way valves 12, 13 and leading to a second servo valve 14. The line leads via a further non-return valve 15, a restricter valve 16, a shut off valve 17, a filter 18 and an adjustable differential valve 19 to a water inlet 20 on the mixing head 6.

The air intake 1 is also connected to a line 21 which leads to a third, air, servo valve 22, the outlet of which leads to a first air inlet 23 of a water dispenser 24.

As is shown more clearly in Figure 2, the water dispenser 24 comprises a dual action piston 25 sliding within a cylinder 26 and defining a chamber 26'. The said first air inlet 23 is located at one end of the cylinder 26, and a second air input 27 is located at the opposite end. This second air inlet 27 is connected to the air intake 1 via a line 28, a fourth, air, servo valve 29 and a dump line restrictor 30.

The dispenser is provided with a water input/output 31 which communicates via a line 32 with line 11, joining that line at a point between the two non-return valves 12 and 13.

Parts of a drill are shown schematically in Figure 1, namely a drill feed cylinder 33, with associated drill feed control valve 34, and a drill motor 35, with associated drill rotation control valve 36. A hydraulic input line 37 serving the drill feed cylinder 33 leads also via line 38 to the respective controls of the second and fourth servo valves 14, 29. A hydraulic output line 39 serving the feed cylinder 33 communicates with the control of the third servo valve 22. A hydraulic line 40 serving the drill motor communicates with the respective controls of the first servo valve 3 and the differential valve 19.

Thus, in operation, the drill feed cylinder 33 and the drill motor 35 will be actuated to begin a drilling operation. The resulting rise in pressure in line 38 will cause the second and fourth servo valves 14, 29 to open, thus allowing air to be supplied to the left of the dispenser 24 through line 28 and dump line restrictor 30.

This inflow of air to the dispenser 24 urges the piston 25 to the right and impels water in the chamber 26' out through the outlet 31 and line 32 to line 11. Because of non-return valve 12, the water flowing into line 11 is constrained to flow through the fourth servo valve 14 (which, as explained above, is open) and hence into the mixer 6.

Simultaneously, the rise in pressure in control line 40 for the drill motor 35 will cause the first servo valve 3 to open, thus allowing pressurised air through lines 2 and 4 into the mixing head 6. During drilling, therefore, the mixing head 6 is supplied with both water and air and creates the desired mist.

If the drill speed drops, for example because of an accumulation of debris, servo valve 3 will remain open but the differential valve 19 will close, thus reducing or shutting off the supply of water to the mixing head.

The air blast from the mixing head will aid clearance of the debris, without there being an undesirable amount of water present.

When the drill rod is retracted, the pressure change in line 38 causes the second servo valve 14 to close, preventing further water being supplied to the mixing head, and the pressure change in control line 39 will open the third servo valve 22, thus allowing air to flow through line 21 to the dispenser 24. The air urges the piston to the left and thus draws water into the chamber 26' within the dispenser, via lines 11 and 32. The dispenser is thereby re-charged and ready for the next drilling cycle.

The drill may be of the rotary or rotary percussive type and the control systems are preferably hydraulic or pneumatic, although electrically or mechanically operated valves for the air and water supplies to the dispenser and mixing head could be used in certain situations.

Claims

1. Fluid supply apparatus for use with a drilling device and comprising an air line having an inlet for receiving air under pressure and an outlet for supplying an air/water mixing head for producing a mist to suppress dust from a drilling apparatus, a water line having an inlet for receiving water and an outlet for supplying the mixing head, and impulsion means in the water line for pressurising the water delivered to the water outlet, the impulsion means having pressurising means connected to the air line whereby the pressurised air imparts pressure to the water supply.

2. Fluid supply apparatus according to Claim 1, wherein the impulsion means comprises a piston and cylinder assembly defining a dispensing chamber and connected in the water line, the pressurised air being supplied alternately to one side of the piston assembly.

3. Apparatus according to Claim 2, additionally comprising retraction detector means to detect retraction of the drilling device, and dispensing control means to control tne air supply to the impulsion means to cause tne dispensing chamber to fill wit water when the device is retracted.

4. Apparatus according to claim 3 wherein the piston and cylinder comprises a dual-action piston such that air supply to the second side of the piston assembly causes the dispensing chamber to fill with water.

5. Apparatus according to Claim 3 or 4, including water supply control means to shut off the supply of water to the mixing head when the drilling device is retracted.

6. Apparatus according to any one of the preceding claims, additionally comprising drill penetration speed detector means, and water supply control means adapted to reduce the supply of water to the mixing head when the drill penetration speed falls.

7. Fluid supply apparatus substantially as herein described with reference to the accompanying drawings.

7. Apparatus for supplying air and water to a mixing head for delivering a watergair mist for controlling dust created by a drilling device, the apparatus comprising a pressurised air intake, a water intake, feed detection means to detect whether drill feed in the device is operating, water supply control means to control the supply of water to the mixer when the drill is fed, rotation detection means to detect whether the drill is rotating, and air supply control means to control the supply of air to the mixing head when the drill is rotating.

New or textually amended claims 1 to 7 have been filed as follows: CLAIMS 1. Fluid supply apparatus for use with a drilling device and comprising an air line having an inlet for receiving air under pressure and an outlet for supplying an air/water mixing head for producing a mist to suppress dust from a drilling apparatus, a water line having an inlet for receiving water and an outlet for supplying the mixing head, and impulsion means in the water line for pressurising the water delivered to the water outlet, the impulsion means having a piston and cylinder assembly defining a dispensing chamber connected in the water line, and means connected in the air line for supplying pressurised air to the piston to dispense water from the chamber.

2. Apparatus according to Claim 1 wherein the piston and cylinder assembly is double acting and air from the air line is supplied to one side of the piston in a dispensing operation and to the opposite side of the piston to cause the dispensing chamber to fill.

3. Apparatus according to Claim 1 or 2, additionally comprising retraction detector means to detect retraction of the drilling device, and dispensing control means to control the air supply to the impulsion means to cause the dispensing chamber to fill with water when the device is retracted.

4. Apparatus according to Claim 3, including water supply control means to shut off the supply of water to the mixing head when the drilling device is retracted.

5. Apparatus according to any one of the preceding claims, additionally comprising drill penetration speed detector means, and water supply control means adapted to reduce the supply of water to the mixing head when the drill penetration speed falls.

6. Apparatus according to Claim 1 including feed detection means to detect whether drill feed in the device is operating, water supply control means to control the supply of water to the mixing head when the drill is fed, rotation detection means to detect whether the drill is rotating, and air supply control means to control the supply of air to the mixing head when the drill is rotating.