INLET TUBE, ROCK DRILLING RIG AND METHOD OF SAMPLING

Abstract

An inlet tube of a sampling device, a rock drilling rig, and a method for taking samples is provided. The inlet tube is mountable to a dust collecting system of a rock drilling rig and is provided with at least one actively controllable homogenizing element forming a physical element for generating disturbance in flow and to thereby homogenize particle distribution of the drilling cuttings in the flow.

Claims

1. An inlet tube of a sample taking arrangement of a rock drilling rig, the inlet tube being configured to direct a flow of drilling cuttings and air to a sampling point, the inlet tube comprising: a cross-sectional inner shape and dimensions; and a homogenizing section, wherein an inner cross-section of the inlet tube includes at least one homogenizing element forming a physical point of discontinuity, wherein shape and dimensions of the inner cross-section differ locally from sections prior and after the homogenizing section and which homogenizing element is configured to generate a disturbance in the flow and to thereby homogenize particle distribution of the drilling cuttings in the flow at the section after the homogenizing section and prior to the sampling point, wherein the homogenizing element is an active controllable element providing the homogenizing section selectively with the physical point of discontinuity.

2. The inlet tube as claimed in claim 1, wherein the inlet tube includes a bend and the homogenizing section is located at the bend.

3. The inlet tube arrangement as claimed in claim 1, wherein the homogenizing element is a selectively expandable element.

4. The inlet tube arrangement as claimed in claim 1, wherein the inlet tube is made of resilient material and includes at least one actuator at the homogenizing section for directing an external force on an outer surface side of the inlet tube for selectively causing reversible deformation of the structure of the inlet tube at the homogenizing section so that material of a wall of the inlet tube protrudes inwards providing the inlet tube with an inner bulge which serves as the homogenizing element.

5. 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 an inlet tube in accordance with claim 1, the inlet tube having an actively controllable homogenizing element in the dust collecting system preceding the sampling point.

6. A method of sampling in a rock drilling rig, the method comprising: drilling drill holes in a rock surface; collecting produced drilling cuttings from an opening of the drill holes during the drilling by 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 an inlet tube before the sampling point; and changing actively a cross-sectional inner shape and dimensions of the inlet tube locally for spreading drilling cutting particles in the flow evenly across the inner cross-section of the inlet tube, whereby the samples are taken downstream of the mentioned particle spreading.

7. The method as claimed in claim 6, further comprising pressing transversally a reversible deform to a resilient wall structure of the inlet tube at the homogenizing section for changing the cross-sectional inner shape and dimensions of the inlet tube locally by means of an inner bulge formed in response of the pressing.

8. The method as claimed in claim 6, further comprising controlling the change of the cross-sectional inner shape and dimensions of the inlet tube under control of a control unit.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0042] FIG. 1 is a schematic side view of a rock drilling rig for surface drilling, the rock drilling rig being provided with a dust collecting system and sampling means.

[0043] FIG. 2 is a schematic diagram showing basic elements of a dust collecting system and sampling prior executing any separation measures.

[0044] FIG. 3 is a schematic diagram showing some features of an inlet tube.

[0045] FIGS. 4 and 5 are schematic and cross-sectional views of inlet tubes and two different principles to homogenize particle distribution in passing flow.

[0046] FIG. 6 is a schematic side view of a curved inlet tube provided with a controllable bulge at its outer curve.

[0047] FIGS. 7 and 8 are schematic views showing deformation of an inlet tube by means of longitudinal movement of a rod.

[0048] FIGS. 9 and 10 are schematic views showing deformation of an inlet tube by means of an outer circumference of a round rod.

[0049] 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

[0050] 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 to a rock surface. The rock drilling unit 4 has a rock drilling machine 6, which may be arranged movably on a feed beam 7. The rock drilling machine 6 may include an impact device and a rotating device, or alternatively it may be a rotary drilling machine and may be without any impact device.

[0051] A drilling tool 8 is connected to the rock drilling machine 6 and the drilling tool 8 may include one or more drill tubes and a drill bit 9 at its free end. During drilling rock material is broken and drilling cuttings are formed in the drill hole 5. 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.

[0052] The drilling cuttings can be collected by a means of a dust collecting system 10 including a suction unit 11 for producing 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 arrangeable on the drill hole opening 12 and being connected to the collecting tube 13. 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 during the drilling process due to the large amount of the material removed from the drill hole 5.

[0053] 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 include a cyclone, for example. The second separator 16 may be mounted on the carrier 2 in connection with the suction unit 11, for example.

[0054] 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, an inlet tube 18 is located before the sampling device 17. The inlet tube 18 conveys the flow to a sampling point of the sampling device 17. The inlet tube 18 includes a homogenizing element for spreading the drilling cuttings in the flow so that proper samples can be taken from the flow. Operation and structure of the homogenizing element is as it is disclosed in this document.

[0055] 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 homogenizing element of the inlet tube 18, for example. Some control situations and principles are disclosed above. The control unit may include a processor for executing an input computer program product or algorithm, and it may be provided with sensing data and input control parameters.

[0056] FIG. 2 discloses a dust collecting system 10 for sucking drilling cuttings from a drill hole opening 12. The system 10 includes dust collecting tubes 13 for transferring the collected flow via an inlet tube 18 to a sampling device 17 and only then to a separator 15. Thus, a sampling point SP is located between the inlet tube 18 and the separator 15. The inlet tube 18 is provided with a homogenizer for ensuring proper particle distribution in the flow. Samples SA are taken from the flow in accordance with a planned sampling schedule or procedure. The samples SA can be analyzed A either online 21 or later on in a laboratory 22.

[0057] FIG. 3 discloses that an inlet tube 18 includes a homogenizing section 23, wherein an inner cross-section of the inlet tube 18 includes one or more homogenizing elements 24 forming a physical point of discontinuity, wherein shape and dimensions of the inner cross-section differ locally from sections prior and after the homogenizing section 23. The homogenizing section 23 may be located at a bend 25 or at a straight part 26 of the inlet tube 18. The homogenizing element 24 is dynamically controlled 27 and can generate disturbance in the flow when needed. The homogenizing element 24 may have different configurations. It may be based on deformation 28 of shape of the inlet tube 18. Alternatively, it may include an expandable element 29, or a movable element arranged on inner surface of the inlet tube 18.

[0058] FIG. 4 discloses that external force F can be directed towards structure of an inlet tube 18 and thereby cause inwardly protruding bulge 31 at a homogenizing section 23. The produced deformation 28 can serve as a homogenizing element. The external force F may be transmitted mechanically or by any other suitable means to cause the desired deformation on wall of the inlet tube 18. The bulge 31 or protruding deformation can direct solid particles towards a free flow passage area inside the inlet tube 18. The force F is controlled by means of a control unit, for example.

[0059] FIG. 5 discloses a basic principle of an expandable element 29, which is connectable to a pressure circuit, in this example, to a pneumatic circuit, wherein a compressor CO generates pressurized air and wherein a valve V and a control unit CU can control operation of the expandable element 29. Arrows indicate expansion of the expandable element 29. The expandable element 29 serves as a homogenizing element 24 and it may be either integrated as a part of the inlet tube 23, or it may be a separate element mounted on an inner surface of the inlet tube 23, for example.

[0060] It may also be possible to cause the deformation of the wall of the inlet tube 23 by means of an expandable element arranged on an outer surface of the inlet tube 18.

[0061] FIG. 6 discloses an inlet tube 18 provided with a bend 25 having an inner curve 26 and an outer curve 27. A homogenizing section 23 is located at the bend 25 and an actively controllable dynamic homogenizing element 24 is located on a side of the outer curve 27. Spreading of solid particles of flow occurs prior reaching a sampling point SP where a sampling device 17 is located. The sampling device 17 may include a tube or sampling pipe 28 which is partly insertable inside the flow channel, and which is provided with an opening 29 through which material to be collected passes during the sampling. The samples taken can be stored in receptacles or bags, for example.

[0062] FIG. 7 discloses that an inlet tube 18 may be made of resilient material and can be reversible deformed by pushing its outer surface by means of a plunger or pushing element 30 provided with a rounded end 31. Then the deformed wall structure of the inlet tube 18 forms a homogenizing element 24, i.e., a bulge inside a homogenizing section 23, as it is shown in FIG. 8. The pushing element 30 may be moved by means of an actuator A, which may be controlled by a control unit CU, for example. FIGS. 7 and 8 show that original outer surface 32 is pushed inwards and a dent 33 is formed. The disclosed arrangement may be arranged at an outer curve of a bend 25.

[0063] FIGS. 9 and 10 disclose an alternative solution, which differs from the one shown in FIGS. 7 and 8 in that different pushing element 30 is used. Further, in FIGS. 7 and 8 the pushing element 30 is moved in the longitudinal direction towards the outer surface of the inlet tube 18, whereas in FIGS. 9 and 10 an outer surface of the pushing element 30 is pressed against the inlet tube 18. Thereby, in these two alternative solutions, differently shaped deformations and homogenizing element 24 are formed. The shapes and dimensions of the formed homogenizing elements 24 can be adjusted by movement length of the pushing element 30 as well as by dimensions and shapes of the pushing elements.

[0064] 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.