EP0398405B1 - Duel jet method - Google Patents

Abstract

PCT No. PCT/EP90/00557 Sec. 371 Date May 6, 1991 Sec. 102(e) Date May 6, 1991 PCT Filed Apr. 9, 1990 PCT Pub. No. WO90/14200 PCT Pub. Date Nov. 29, 1990.In particular for cutting working of especially hard rock such as granite, an additional cooling medium is supplied to a pressure medium which is at a high pressure of especially more than 1500 bar. The pressure medium is ejected particularly in the form of discrete narrow jets from a nozzle head (5) and the directional jet (5g) of the cooling medium is directed towards at least some of the jets (5b) of the bundle of jets of the pressure medium so that together with the pressure medium a cooling effect is caused on the object to be worked, thus resulting in an improved crushing effect.

Description

The invention relates to a method and an apparatus for cutting, drilling and the like material-removing processing of rock, ores, coal seams, concrete or other hard objects by means of a pressure medium according to the types mentioned in claims 1 and 11.

Such a method and such a device are already known (DE-A-3 739 825). In the nozzle head of the aforementioned device, individual nozzles are arranged at an angle of attack with respect to the main jet direction of the nozzle head, in order to achieve a relatively wide “spread” of the bundle of the individual jets before they “fan out” so far that the edge regions of the individual jets overlap.

It is also known in other generic devices (DE-B-3 410 981 and 3 516 572) to use inserts made of hard metal for the nozzles and to anchor them in the nozzle head by means of screws or insertion.

It is already known from the use of cooling medium. In US-A-3 526 162 cryogas is passed through a nozzle onto the non-metallic material to be cut. A pressure medium jet cutting the material is then directed through a second nozzle onto the supercooled area.

Devices for drilling holes in concrete and rock are also known (MACHINE DESIGN 57/1985, pages 114-117), in which water jets mixed with abrasive particles are placed under high pressure and are used for drilling by means of a rotating nozzle head. A water pressure of up to about 100 bar is used.

Finally, it is also known (CH-A-370 717 and GB-A-718 735) to atomize liquid by air to treat surfaces; rotary nozzles are also used, with the help of which the inner wall of the bore of a workpiece is coated in order to bring it into the final fine machining state. A routing material-removing effect is therefore not achieved.

The invention has for its object to improve the processing of hard objects in particular by clearing groove or groove-shaped slots with a high clearance rate without bulky additional units; above all, the "advance" when slitting the hard material is to be increased.

The invention is characterized in claims 1 and 11 and further embodiments of the same are described in subclaims.

Surprisingly, it has been shown that the inventive Method in which at least one jet of a coolant is directed onto the clearing point of the object with at least one jet of the pressure medium, and a cooling effect is exerted on the object, by means of which a significantly higher clearing rate can be achieved than if this cooling medium is missing. The cooling medium itself does not necessarily have to be cooler than the pressure medium; it suffices if it has a strongly cooling effect at the point of impact on the object to be slit in the area of the impact of the pressure medium jet. For example, the clearance rate is improved by a factor of ³⁻⁴ compared to a lack of cooling medium even if water is used as the pressure medium and air is used as the cooling medium, provided the pressure of the water is at least 1500 bar. It is assumed that by the coincidence of the high-pressure water with the directional jet or with several directional jets of the air, so much heat is removed from the water before it hits hard granite, for example, that substantial heating of the granite can be avoided. Investigations have shown that, in the absence of the cooling medium, the granite at the base or bottom of the groove-shaped slot is heated so strongly that a glassy or ceramic-like coating layer forms there, which greatly reduces the clearing rate. The invention avoids the formation of such a coating layer, which offers high resistance to machining, above the granite. In addition, the interplay of the rays, which heat up the rock considerably when the punctiform pressure medium jets strike it, with the same rock location when the brush beam is oscillating, has a favorable effect on crack formation in the rock and on its breaking up and particle-like destruction.

The object of the invention is particularly well achieved when the pressure medium in the form of several narrow individual jets is ejected from a nozzle head under the high pressure of up to and above 2000 bar and when the individual narrow jets are not parallel but in the form of an increasing Distance from the end face of the nozzle head diverging beams are arranged. It is particularly expedient if the density (per unit area) of rays in the central area of the bundle is significantly greater than in the edge area.

In addition, it is advisable if directional jets of the cooling medium are directed onto the jets of the pressure medium in such a way that directional jets and individual jets of the pressure medium intersect. Even if the jet of the cooling medium is deflected from the original direction of the directional jet by individual jets of the pressure medium under high pressure, there are strong cooling effects since the speed of the pressure medium jets is very high and is up to over 2000 km / h. If air is used as the cooling medium, an air pressure in the order of magnitude between 1 and 10 bar is sufficient. Icing effects promote the destruction in the impact area on the rock.

At least in part, a cool liquid gas can also be used instead of air, which improves the results even more, but which also increases the process costs considerably.

In addition, abrasive particles, in particular the cooling medium and / or the pressure medium, can also be added.

The problem is particularly preferably solved by a Device in which the nozzle head for the pressure medium and a straightening head for the cooling medium are arranged side by side so that the above-mentioned effect occurs. It is particularly recommended if at least the nozzle head of the pressure medium exerts an oscillating movement in an oscillating plane which corresponds to the longitudinal direction of the groove-shaped slot to be cleared out of rock or the like. The individual jets of the pressure medium are arranged at different angles of attack in relation to this pendulum plane. It is also advisable to use nozzles that prevent the individual jets from spreading out shortly after leaving the nozzle head. Rather, the individual jets should strike the object essentially in a point-like manner - in the form of a line when commuting, unless the cooling medium exerts an "icing" effect on the pressure medium jets. The angles of attack are in particular up to 25 degrees with respect to the pendulum plane. The pressure medium supply line is expediently bendable, while the coolant supply line can be rigid.

The invention and particularly preferred embodiments thereof are explained in more detail below with reference to the drawings.

• Fig. 1 eine schematische Ansicht auf eine Vorrichtung nach der Erfindung;
• Fig. 2 einen schematsichen Schnitt II-II durch die in Fig. 1 dargestellte Vorrichtung;
• Fig. 3 eine schematische Ansicht gemäß Fig. 1 einer anderen Ausbildung der Vorrichtung;
• Fig. 4 eine teilweise Querschnittsansicht durch eine Vorrichtung gemäß der Erfindung - hier ohne Richtkopf für das Kühlmedium - und zwar mit einem Querschnitt durch den rinnenförmigen Schlitz in Granit;
• Fig. 5 eine schematische Ansicht einer anderen Ausbildung der Erfindung;
• Fig. 6 eine Ansicht der Stirnseite eines Düsenkopfes;
• Fig. 7 einen Querschnitt A-B von Fig. 6 und
• Fig. 8 einen Querschnitt A-C von Fig. 6 des Düsenkopf;
• Fig. 9 einen teilweisen Querschnitt einer Düse;
• Fig. 10 eine aufgebrochene Seitenansicht eines anderen Düsenkopfes und
• Fig. 11 eine schematische Erläuterung des Gesteinszertrümmerns.

Show:

• Figure 1 is a schematic view of a device according to the invention.
• Fig. 2 is a schematic section II-II through the device shown in Fig. 1;
• FIG. 3 shows a schematic view according to FIG. 1 of another embodiment of the device;
• Figure 4 is a partial cross-sectional view through a device according to the invention - here without a straightening head for the cooling medium - with a cross-section through the channel-shaped slot in granite;
• Fig. 5 is a schematic view of another embodiment of the invention;
• 6 shows a view of the end face of a nozzle head;
• Fig. 7 shows a cross section AB of Fig. 6 and
• 8 shows a cross section AC of FIG. 6 of the nozzle head;
• 9 is a partial cross section of a nozzle;
• Fig. 10 is a broken side view of another nozzle head and
• 11 is a schematic explanation of the rock crushing.

1, a rigid pressure medium supply line 12 is connected via connecting webs 36 to the likewise rigid supply line 31 for cooling medium. Both the pressure medium supply line 12 and the cooling medium supply line 31 are parallel arranged pipes. At the free end of the tube 12, a coupling 11 is attached, which connects the pressure medium supply line 30, which is designed as a flexible pendulum tube, to the tube 12 in such a way that the pendulum tube around the articulation point of the coupling 11 in a pendulum movement - as indicated in broken lines - by, for example, the pivoting angle α is feasible. Instead of the coupling 11, for example, according to FIG. 3, a high-pressure hose (HP hose) can also be installed between the tube 12 and the pendulum tube in such a way that the pressure medium flows through the bendable HP hose, which causes the oscillating movement of the pendulum tube, ie the pressure medium Feed line 30, not obstructed in operation.

The supply line 30, which oscillates during operation, is supported on a guide 6 which projects laterally from the cooling medium supply line 31. At the free end of the pendulum tube there is the nozzle head 3, on the front or front side 3a of which nozzles (not shown here) are arranged, through which pressure medium can be expelled onto the rock 15 in operation in the form of jets 5b in the form of jets 5b . The oscillating movement to the right and left by the pivoting angle α oscillating movement of the pendulum tube and therefore also the entrained nozzle head 3 and the jets 5b is caused in this example by a drive unit 32 which is attached to the cooling medium supply line 31 and by an energy source, for example Kinetic, electrical, electromagnetic, pneumatic or hydraulic energy can be driven, which is guided through the feed line 31 to the drive unit 32. A plunger 33 briefly pushes the pendulum tube in the direction facing away from the feed line 31. As a result, the spring 34 is tensioned, which on the one hand prevents the pendulum tube from being deflected too far and on the other hand pulls it back in the opposite direction. Due to the combination effect of the drive unit 32 and the spring 34 with the pendulum tube, the latter swings back and forth between the broken lines. The narrow rays 5b strike the rock 15 and clear a channel-shaped slot 16 there when the device is gradually guided in the direction of the arrow P along the front of the rock 15.

In the vicinity of the nozzle head 3 for the pressure medium under high pressure, the straightening head 31a is located at the free end of the feed line 31, through the straightening beams 5g of air serving as a cooling medium, both in the direction of the rock 15 and in the direction of the individual pressure medium jets 5b are directed.

This device is encased in a protective manner by the housing 40 shown schematically here, except for its open end face.

In the alternative of the device shown in FIG. 3, instead of the tappet 33, a linkage composed of several levers is used, with which the drive unit 32 brings the feed line 30 of the pressure medium into the oscillating movement. The directional jet 5g is inclined at 45 degrees to the main jet direction of the pressure medium, which is illustrated here by the jet 5b of the nozzle head 3; In this embodiment, the other rays of the pressure medium are not specified.

4 schematically illustrates the width C of the channel-shaped slot 16 to be cleared from the rock 15. Nozzles 5a are located in the nozzle head 3 for the pressure medium, which can optionally also be in the form of jet cones spreading from the nozzle head 3 with increasing direction, although narrow individual jets have proven to be considerably cheaper.

5 is the most preferred; the pressure medium emerging from the nozzle head 3 in the form of the narrow individual jets 5b under high pressure serves to automatically drive the bendable pendulum tube or the feed line 30 in the direction which is predetermined by the bow-shaped, in particular linear guide 6. Here the pendulum plane lies in the drawing plane, that is, in the same plane in which the supply line 12 for the pressure medium on the one hand and the supply line 31 for the coolant on the other hand are located. This embodiment of the invention also ensures that at least one directional jet 5g of the air serving as the cooling medium emerges from the directional head 31a in such a way that an at least fictitious interface 200b with the next adjacent jet 5b of the pressure medium results before the rock (not shown here) is reached .

6, 7 and 8, a particularly preferred embodiment of a nozzle head is demonstrated. The rectangular nozzle head 3 has on its free front or face 3a a number of nozzles 5a, of which the middle nozzle 5a1 at the interface between the plane of symmetry 25s (simultaneously forms the pendulum plane PE) and the transverse plane 25q running at right angles thereto is arranged. Further nozzles 5a are arranged in the central region 3a1 around the central nozzle 5a1, so that the density, ie the number of nozzles per unit area, in the central region 3a1 is larger than outside it. The outermost nozzles 5a2 are formed by nozzle elements, which are explained in more detail with reference to FIG. 9.

Bores with an internal thread 50 are arranged in the nozzle head 3 starting from the end face 3a in such a way that the axes of the bores are inclined at angles of incidence β and δ with respect to the axis of the central nozzle 5a1 and therefore the main jet direction. The rays 5b2 therefore extend diametrically outwards from the end face 3a of the nozzle head 3. It is recommended if the angle of attack in the pendulum plane PE is significantly larger than the angle of attack β in the transverse plane 25q running transversely thereto. In this example, the first-mentioned angle of attack δ₂ is 23 degrees, while the second-mentioned angle of attack β₂ is 6 degrees. The nozzle elements consist of the screw bolts 100 which can be screwed into the internal thread 50 from the end face 3a and the cylindrical projections 101 which expediently protrude into the collecting chamber 7 in the nozzle head 3. The collecting chamber 7 is connected by a passage provided with an internal thread 20 to the feed line 30, not shown in FIG. 7, for the pressure medium. The clear diameter of the nozzles 5a in the area of the passage opening 102a is 0.5-1 mm.

It is advisable if the screw bolt 100 made of steel in particular is provided with an annular insert 102 made of sapphire and / or hard metal in particular, the passage opening 102a of which has the smallest flow cross section of all the units involved in the passage of the pressure medium. The approach 101 of the screw bolt 100 has a flow cross section which decreases conically in the flow direction D of the pressure medium. It is at the entrance of the approach 101, a perforated disk 103 is soldered on, for example. The total cross section of all perforation holes 103a in the disk 103 is larger than the flow cross section of the passage opening 102a of the ring-shaped insert 102. One part of the attachment 101 connects to the insert 102, which has a substantially cylindrical bore 101b, to which the conical collecting chamber is attached 101a connects. The perforated disk 103, together with the conically or conically narrowing collecting chamber 101a, reduces pressure surges. This ensures better that the individual jets 5b1, 5b2 of the pressure medium remain narrow up to the point of impact on the object to be processed.

In the special embodiment of FIG. 10, the coolant supply line 31 coaxially envelops the pressure medium supply line 30; both supply lines are bendable, the pressure medium supply line 30 consisting of a high-pressure hose, since the pressure medium pressure within it is very high. While the pressure medium exits through the nozzles, here the nozzles 5a1 and 5a2, and forms pressure medium jets 5b1, 5b2, 5b3, and the nozzle head 3 swings back and forth very quickly in the pendulum plane PE, ie perpendicular to the plane of the drawing, this becomes bundles of rays formed by the individual, very narrow jets 5b1, 5b2, 5b3 and possibly further individual jets are enveloped by a kind of "curtain" of air which flows as a cooling medium through the annular directional nozzle 201. The axis of the directional nozzle 201 is directed radially inward at the angle of incidence γ of approximately 20 °, with the result that the angle of the beam 5b2 at the angle of incidence β relative to the central jet 5b1 is at least fictitiously hit or cut at the interface 200b2 by the directional jet 5b . In fact, the Directional jet 5g of the negative pressure is deflected around the jet 5b2, which flows out of the nozzle 5a2 at a very high speed of, for example, 2000 km / h.

In addition, it was found that it is not always necessary for the directional jets 5g to intersect such jets 5b even before the pressure medium jets 5b strike the object 15, although this "touching" of the cooling medium, for example the air of the directional jet 5g, with the high pressure Pressure medium leads to a strong cooling even before hitting the rock 15.

According to FIG. 11, the directional jet 5g does not directly meet the jet 5b of the pressure medium; rather, the directional jet 5g and the pressure medium jet 5b are pivoted essentially parallel to one another during the oscillating oscillating movement of the nozzle head 3 by the pivoting or pendulum angle α from one position to the other dot-dash position, in which the directional jet with the reference symbol 5g 'and the pressure medium jet are provided with the reference symbol 5b '. Due to the high energy with which the jet 5b, 5b 'of the pressure medium, for example water, with the pressure of 2000 bar in the impact area 209 at the beginning of the slot 16 on the granite rock 15 at the impact points 210 - and shortly afterwards 210' - strikes, there is a sudden heating of the granite by the high-energy pressure medium jets 5b, 5b '. A short time later, directional rays 5g 'of the air touch the same impingement area 209, for example at the impingement point 211' with a sudden, significant temperature reduction. This rapid interplay of heating and cooling within a short time of less than a second and within short ranges leads to downright explosive crack formation in the rock, so that particles flake off or burst off. The removal or clearing effect in the impact area 209 is therefore many times greater than if only the pressure medium jets 5b, 5b 'would oscillate there and back. The heating without interruption of cooling (without the use of the cooling directional jets) forms a coating that serves as a heat shield for many types of rock, especially in the area of impact, which shows the effect of the high-energy jets 5b, 5b 'in the case of longer operation compared to the beginning of clearing when the rock is not yet very strong is heated, reduced.

The invention can be used particularly advantageously when introducing straight or also arcuate or even circular slots in granite and the like hard rock. Thus, the device according to the invention can cut slots up to one meter deep in granite, so that granite blocks can be broken out much more quickly and easily than by introducing boreholes and blasting with explosives in a predetermined cuboid shape. The media used in the invention, such as water for the high pressure medium and Air for the cooling medium, cheap and the lance-shaped device offers the possibility of clearing even deep slots in the granite with a narrow design. The alternating stress between heating effects when the punctiform individual jets of the pressure medium strike the rock and the cooling effect of cool media there leads to "brittleness" of the rock in contrast to previously known methods in which, without using the cooling medium, a hard material opposing the removal of granite - plating revealed.

Claims (19)

1. A method of material-removing working such as cutting of rock, ore, coal, concrete or other hard objects with the aid of a pressure medium which in the form of narrow jets (5b) oriented at angles of incidence (β) to each other is directed at high pressure towards the object (15) such that particles thereof will be removed to form a slot (16) in said object (15),
   characterized in that the object (15) in the area of impact (209 to 211) of the jets (5b) of pressure medium is cooled by at least one directional jet (5g) of a cooling medium and that the directional jet(s) (5g) is (are) oriented relative to at least one jet (5b) of pressure medium such that the directional jet(s) (5g) will strike the area of impact (205 to 211) together with the jet (5b) of pressure medium.
2. The method as claimed in claim 1, characterized in that the density (number of jet nozzles per unit of area) of the jets (5b) is selected to be substantially greater in the central area (3a1) of the bundle of jets composed of the discrete narrow jets (5b) than outside of said central area (3a1).
3. The method as claimed in claim 1 or claim 2, characterized in that the directional jet(s) (5g) are directed towards narrow jets (5b) of pressure medium such that the points of intersection or the line of intersection (200b2) of the directional jet (5g) with at least the outermost narrow jet (5b) of pressure medium is (are) at a distance from the point of impact (210, 211) on the object (15).
4. The method as claimed in any of the preceding claims, characterized in that an annular directional jet (5g) of the cooling medium is directed towards the bundle of jets composed of said discrete jets (5b).
5. The method as claimed in any of the preceding claims, characterized in that pressure medium at a high pressure of at least 1500 bar is employed.
6. The method as claimed in any of the preceding claims, characterized in that cool water is used as said pressure medium.
7. The method as claimed in any of the preceding claims, characterized in that air is used as the cooling medium.
8. The method as claimed in any of the preceding claims, characterized in that cold liquefied gas is used as the cooling medium.
9. The method as claimed in any of the preceding claims, characterized in that abrasive particles are added to the pressure medium.
10. The method as claimed in any of the preceding claims, characterized in that the pressure medium and/or the cooling medium is pressurized in pulsating fashion.
11. An apparatus for carrying out the method as claimed in any of the claims 1 to 10, in which the pressure medium is supplied through a supply line (30) to a nozzle head (3) and is adapted to be directed in the form of narrow jets (5b) through at least two nozzles (5a) thereof towards the object (15) to be worked, characterized in that said apparatus comprises a directional head (31a) which is connected to a supply line (31) for cooling medium and includes at least a directional nozzle (201) the jet orientation of which is positioned relative to at least one jet (5b) of pressure medium so that the directional jet (5g) of cooling medium strikes the impacting area (209-211) together with the jet (5b).
12. The apparatus as claimed in claim 11, characterized in that the angle of incidence (β) of the plurality of nozzles (5) is selected to be between about 10 and 25°.
13. The apparatus as claimed in claim 11 or claim 12, characterized in that the pressure-medium supply line (30) is substantially flexible.
14. The apparatus as claimed in any of the claims 1 to 13, characterized in that the pressure-medium supply line (20) is guided by guide means (6) in the plane of oscillation (PE), said guide means being connected to the substantially rigid cooling-medium supply line (31).
15. The apparatus as claimed in any of the claims 11 to 14, characterized in that within the nozzle head (3) communicating passages are provided for communicating the nozzles (5a) on one side with a manifold chamber (7) into which the pressure medium flows via the supply line (30) and on the other side with the end face (3a) of the nozzle head (3).
16. The apparatus as claimed in claim 15, characterized in that each nozzle (5a) comprises a tubular bolt (100) adapted to be screwed into internal threads (50) of the nozzle head (3) leading to a communicating passage.
17. The apparatus as claimed in claim 16, characterized in that an annular insert (102) made from sapphire and/or cutting metal is fitted in said bolt (100), the flow port (102a) of said insert having the smallest flow cross-section of all members participating in the passage of pressure medium.
18. The apparatus as claimed in claim 16 or claim 17, characterized in that the bolt (100) is provided with an extension (101) the flow cross-section of which decreases conically in the direction (D) of flow of the pressure medium.
19. The apparatus as claimed in claim 18, characterized in that the inlet to the extension (101) is covered by a perforated disk (103) the clear overall flow cross-section of all perforations (103a) thereof being greater than the flow cross-section of the flow port (102a) of the insert (102).

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