Homogenizer, rock drilling rig and method of sampling

Abstract

A homogenizer for homogenizing flow, a rock drilling rig, and a method for taking samples is provided. The homogenizer is mountable to a dust collecting system of the rock drilling rig and is arranged for effecting on the flow, which contains air and drilling cuttings. The homogenizer includes a channel part through which the flow is directed and at least one air jet for directing air blows to the flow for generating disturbance in the flow and to thereby homogenize particle distribution of the drilling cuttings in the flow.

Claims

1. A rock drilling rig comprising: a movable carrier; at least one drilling boom mounted on the carrier and including a rock drilling unit provided with a rock drilling machine; a dust collecting system arranged for removing drilling cuttings from an opening of a drilled hole, wherein the dust collecting system is provided with a suction unit, dust collecting tubing, and at least one separator for separating solid particles from flow containing air and the drilling cuttings; at least one sampling point for taking samples of the flow, wherein the sampling point is located prior to the separator so that the flow is still unseparated at the sampling point; and a homogenizer in the dust collecting system preceding the sampling point, the homogenizer including a channel part through which the flow is directed; and at least one air jet arranged on an inner surface of the channel part arranged for directing air blows to the flow for generating a disturbance in the flow and to thereby homogenize particle distribution of the drilling cuttings in the flow.

2. The rock drilling rig as claimed in claim 1, wherein the channel part includes a bend and the at least one air jet is located at the bend.

3. The rock drilling rig as claimed in claim 1, wherein the channel part includes a bend with an inner curve and an outer curve, and wherein the at least one air jet is provided on the outer curve of the bend.

4. The rock drilling rig as claimed in claim 1, wherein the at least one air jet comprises several air jets in transverse cross-section of the channel part, whereby the several air jets are orientated in different radial directions relative to each other.

5. The rock drilling rig as claimed in claim 1, wherein the magnitudes of the air blows of the at least one air jet is controllable under control of a control unit.

6. The rock drilling rig as claimed in claim 1, further comprising at least one compressor arranged for generating pneumatic pressure to a pneumatic system and wherein the homogenizer is connected to the pneumatic system and is controllable by at least one control valve.

7. A method of sampling in a rock drilling rig, wherein the method comprises: drilling drill holes in a rock surface; collecting produced drilling cuttings from an opening of the drill holes during the drilling by means of a dust collecting system; taking samples of flow containing air and drilling cuttings at a sampling point of the dust collecting system during the drilling; providing the dust collecting system with a homogenizer before the sampling point; directing transverse air blows to the flow and thereby spreading drilling cutting particles in the flow to even out particle distribution of the flow; and taking the samples downstream the mentioned particle spreading.

8. The method as claimed in claim 7, comprising controlling the spreading of the solid particles in the flow by directing several air blows in different transverse directions towards the flow.

9. The method as claimed in claim 7, comprising providing the at least one air jet with continuous air flow during the selectively controlled spreading measures of the solid particles.

10. The method as claimed in claim 7, comprising directing pressure air pulses or impacts to the flow when executing the spreading of the solid particles.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a schematic side view of a rock drilling rig for surface drilling provided with a dust collecting system and sampling means.

(2) FIG. 2 is a schematic diagram showing basic elements of a dust collecting system and sampling prior executing any separation measures.

(3) FIG. 3 is a schematic diagram showing some features of a homogenizer.

(4) FIGS. 4 and 5 are schematic and cross-sectional views of channel parts of two homogenizers and respective air jet arrangements.

(5) FIGS. 6 and 7 are schematic side views of curved channel parts provided with air jets.

(6) FIG. 8 is a schematic diagram of some features of an air jet.

(7) For the sake of clarity, the figures show some embodiments of the disclosed solution in a simplified manner. In the figures, like reference numerals identify like elements.

DETAILED DESCRIPTION

(8) FIG. 1 discloses a rock drilling rig 1 including a movable carrier 2 and a drilling boom 3 mounted on the carrier 2. The drilling boom 3 is provided with a rock drilling unit 4 for drilling drill holes 5 in a rock surface. The rock drilling unit 4 includes a rock drilling machine 6, which may be arranged movably on a feed beam 7.

(9) The rock drilling machine 6 may have an impact device and a rotating device, or alternatively it may be a rotary drilling machine and may be without any impact device. A drilling tool 8 is connected to the rock drilling machine 6 and the drilling tool 8 may have one or more drill tubes and a drill bit 9 at its free end. During the drilling, rock material is broken and drilling cuttings are formed in the drill hole 5.

(10) The drilling cuttings needs to be flushed away from the drill hole 5. Typically, pressurized air is produced by means of a compressor CO and the pressurized air is directed via the drilling tool 8 to a bottom of the drill hole 5, whereby drilling cuttings are flushed away. The drilling cuttings can be collected by a means of a duct collecting system 10 having a suction unit 11 for production negative pressure so that the drilling cuttings can be sucked from a drill hole opening 12 via dust collecting tubes 13. There may be a suction basket 14 mountable on the drill hole opening 12 and being connected to the collecting tube 13.

(11) A main purpose of the dust collecting system 10 is to transfer the drilling cuttings away from the drill hole opening 12 so that visibility to the drilled target is good and no difficulties occur for the drilling process due to large amount of the material removed from the drill hole 5. However, the dust collecting system 5 may also have one or more separators for processing the collected material. There may be a first separator 15 for separating coarse particles and a second separator 16 for separating fine particles. The first separator 15 may be mounted on the drilling boom 3 and it may comprise a cyclone, for example. The second separator 16 may be mounted on the carrier 2 in connection with the suction unit 11, for example.

(12) A sampling device 17 for taking samples out of flow of drilling cuttings and air in the system is arranged before the first separator 15, whereby it is located prior to any separation phase. Further, a homogenizer 18 is arranged before the sampling device 17 for ensuring that the flow directed to the sampling device 17 is concentrated. The homogenizer 18 spreads the drilling cuttings in the flow so that proper samples can be taken from the flow. The homogenizer 18 operates by means of pressurized air wherefore pressure air is conveyed from an output port 19 of the compressor CO to a pressure feed line 20 of the homogenizer 18.

(13) The rock drilling rig 1 may have one or more control units CU for controlling the operation and actuators. The control unit CU may control the sampling device 17 and the homogenizer 18, for example. Some control situations and principles are disclosed above. The control unit may have a processor for executing an input computer program product or algorithm, and it may be provided with sensing data and input control parameters.

(14) FIG. 2 discloses a dust collecting system 10 for sucking drilling cuttings from a drill hole opening 12. The system 10 has dust collecting tubes 13 for transferring the collected flow via a homogenizer 18 to a sampling device 17 and only then to a separator 15. Thus, a sampling point SP is located between the homogenizer 18 and the separator 15. Samples SA are taken from the flow in accordance with a planned sampling schedule or procedure. The samples SA can be analyzed either online at 21 or later on in a laboratory 22.

(15) The sampling device 17 may have a tube or sampling pipe, which is partly insertable inside the flow channel, and which is provided with an opening through which material to be collected passes during the sampling. The samples taken can be stored in receptacles or bags, for example.

(16) FIG. 3 discloses that a homogenizer 18 includes a channel part 23 for conveying flow of air and drilling cuttings through it. The channel part 23 is provided with one or more air jets 24 for directing air blows 25 towards the flow and causing thereby desired disturbance 26 in the flow.

(17) FIG. 4 discloses a homogenizer 18 wherein one air jet 24 is arranged on a wall of a channel part 23. Feeding of pressurized air from a compressor CO can be controlled by means of a valve V, which may be controlled by means of control unit CU. FIG. 4 shows that solid particles P in the flow are not distributed evenly, wherefore the particle distribution needs to be improved by directing air blows in transverse direction to the flow. After this pneumatic particle separation control easier and more reliable sampling is possible.

(18) FIG. 5 discloses the same pneumatic control principle as disclosed in FIG. 4, but several air jets are utilized instead of one.

(19) FIGS. 6 and 7 both disclose that a channel part 23 of homogenizer 18 includes a bend 27 provided with an inner curve 28 and an outer curve 29. One or more air jets 24 are mounted on the outer curve 29 of the bend 27. In FIG. 6 the cross-section of the channel part 23 may have one air jet 24 or several air jets arranged in different radial angles. In FIG. 7 there are several air jets 24 arranged one after each other in longitudinal direction of the bend 27.

(20) FIG. 8 discloses that air jet 24 may have a nozzle element 30 including a frame 31 or body and mounting elements 32 for mounting it to a channel part. Further, there are one or more jet orifices 33 through which the air blows are directed. The nozzle element 30 is provided with a feed port or connection 34 for connecting it with a pneumatic channel for feeding pressure air.

(21) In one example, mounting of the nozzle element 30 includes drilling a hole in a wall of the channel part, inserting the nozzle element 30 into the drilled hole and tightening the nozzle element 30 in place with screw members. Finally, the nozzle element is connected to the pneumatic channel.

(22) Although the present embodiments have been described in relation to particular aspects thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred therefore, that the present embodiments be limited not by the specific disclosure herein, but only by the appended claims.