Water-abrasive-suspension cutting system

Abstract

A water-abrasive suspension cutting facility with at least one high-pressure source (2) which provides a carrier fluid at a high pressure, with at least one exit nozzle (6), with a high-pressure conduit (4) connecting the high-pressure source (2) to the exit nozzle (6), as well as with an abrasive agent feed lock (16). The abrasive agent feed lock (16) is connected to the high-pressure conduit (4) and includes an entry side shut-off element (26) and an exit-side shut-off element (24). A lock chamber (18) is arranged between the entry side shut-off element (26) and an exit-side shut-off element (24). A suction device (30) is configured for producing a reduced pressure in the lock chamber (18) and is connected to the lock chamber (18).

Claims

1. A water-abrasive suspension cutting facility comprising: at least one high-pressure source, which high pressure source provides a carrier fluid at a high pressure; at least one exit nozzle; a high-pressure conduit connecting the at least one high-pressure source to the at least one exit nozzle; an abrasive agent feed lock, which feed lock is connected to the high-pressure conduit and which feed lock comprises an entry-side shut-off element and an exit-side shut-off element and a lock chamber arranged between the entry-side shut-off element and the exit-side shut-off element; and a suction device configured to be activated when the entry-side shut-off element is opened for producing a reduced pressure in the lock chamber, the suction device being connected to the lock chamber, wherein the lock chamber runs out via the exit-side shut-off element into a pressure container which is situated in the high-pressure conduit or a branch of the high-pressure conduit.

2. A water-abrasive suspension cutting facility according to claim 1, wherein the suction device comprises a cylinder with a piston which is movable in the cylinder, wherein one end of the cylinder is open to the lock chamber.

3. A water-abrasive suspension cutting facility according to claim 2, wherein the piston is movable via an electric, pneumatic or hydraulic drive.

4. A water-abrasive suspension cutting facility according to claim 2, wherein the piston is hydraulically movable, wherein the piston is connected to a drive piston in a drive cylinder, and the drive piston in the inside of the drive cylinder is subjected to carrier fluid from the high-pressure conduit, for moving the piston.

5. A water-abrasive suspension cutting facility according to claim 4, wherein the drive cylinder is connected at least one side of the drive piston to the high-pressure conduit via at least one valve.

6. A water-abrasive suspension cutting facility according to claim 1, wherein departing from the high-pressure source, a main branch of the high-pressure conduit is led past the pressure container, and the pressure container is situated in an auxiliary branch parallel to the main branch, wherein the main branch and the auxiliary branch unify upstream of the exit nozzle.

7. A water-abrasive suspension cutting facility according to claim 1, wherein the lock chamber is connected to the high-pressure conduit via a pressure conduit, wherein a pressure compensation valve in the form of a shut-off valve is arranged in the pressure conduit, and the lock chamber can be subjected to pressure by way of opening the pressure compensation valve.

8. A water-abrasive suspension cutting facility according to claim 1, wherein the lock chamber is connected to a drain conduit which is connected to a pressureless run-off via a second pressure-compensation valve in the form of a shut-off valve, wherein the drain conduit can be opened to the pressureless run-off by way of opening the second pressure compensation valve.

9. A water-abrasive suspension cutting facility according to claim 1, further comprising a drain conduit, an accumulator with a pressure space, wherein the lock chamber is connected to the drain conduit which ends in the pressure space of the accumulator.

10. A water-abrasive suspension cutting facility according to claim 9, wherein the accumulator comprises a cylinder accumulator, and the drain conduit ends in the pressure space comprising a first pressure space of the cylinder accumulator, in which cylinder accumulator a piston, separating the first pressure space from a second pressure space, is movably arranged, wherein the second pressure space can be subjected to pressure and relieved of pressure, via at least one valve.

11. A water-abrasive suspension cutting facility according to claim 10, wherein the second pressure space of the cylinder accumulator can be switchably brought into connection with the high-pressure conduit or with a pressureless outlet, via the at least one valve.

12. A water-abrasive suspension cutting facility according to claim 9, wherein a throttle is arranged in the drain conduit, upstream of the accumulator.

13. A water-abrasive suspension cutting facility according to claim 1, further comprising at least one pressure accumulator, wherein the high-pressure conduit is connected to the at least one pressure accumulator.

14. A water-abrasive suspension cutting facility according to claim 1, further comprising an abrasive agent reservoir with an exit and a movable closure element arranged in the exit, the abrasive agent reservoir containing an abrasive agent, wherein the lock chamber is connected via the entry side shut-off element to the exit of the abrasive agent reservoir, wherein said closure element has a hollow configuration that is open to an upper and to a lower end, wherein the closure element lower end closes the exit and with upper end extends beyond a maximal filling level for the abrasive agent.

15. A water-abrasive suspension cutting facility comprising: at least one high-pressure source, which high pressure source provides a carrier fluid at a high pressure; at least one exit nozzle; a high-pressure conduit connecting the at least one high-pressure source to the at least one exit nozzle; an abrasive agent feed lock, which feed lock is connected to the high-pressure conduit and which feed lock comprises an entry-side shut-off element and an exit-side shut-off element and a lock chamber arranged between the entry-side shut-off element and the exit-side shut-off element; a suction device connected to the lock chamber; and a drain conduit, an accumulator with a pressure space, wherein the lock chamber is connected to the drain conduit which ends in the pressure space of the accumulator.

16. A water-abrasive suspension cutting facility according to claim 15, wherein the accumulator comprises a cylinder accumulator, and the drain conduit ends in the pressure space comprising a first pressure space of the cylinder accumulator, in which cylinder accumulator a piston, separating the first pressure space from a second pressure space, is movably arranged, wherein the second pressure space can be subjected to pressure and relieved of pressure, via at least one valve.

17. A water-abrasive suspension cutting facility according to claim 16, wherein the second pressure space of the cylinder accumulator can be switchably brought into connection with the high-pressure conduit or with a pressureless outlet, via the at least one valve.

18. A water-abrasive suspension cutting facility according to claim 15, wherein a throttle is arranged in the drain conduit, upstream of the accumulator.

19. A water-abrasive suspension cutting facility comprising: at least one high-pressure source, which high pressure source provides a carrier fluid at a high pressure; at least one exit nozzle; a high-pressure conduit connecting the at least one high-pressure source to the at least one exit nozzle; an abrasive agent feed lock, which feed lock is connected to the high-pressure conduit and which feed lock comprises an entry-side shut-off element and an exit-side shut-off element and a lock chamber arranged between the entry-side shut-off element and the exit-side shut-off element; and a suction device connected to the lock chamber, wherein the lock chamber is connected to a drain conduit which is connected to a pressureless run-off via a second pressure-compensation valve in the form of a shut-off valve, wherein the drain conduit can be opened to the pressureless run-off by way of opening the second pressure compensation valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1 is a schematic view showing a water-abrasive suspension cutting facility according to a first embodiment of the invention;

(3) FIG. 2 is a schematic view showing a water-abrasive suspension cutting facility according to a second embodiment of the invention;

(4) FIG. 3 is a schematic view showing a water-abrasive suspension cutting facility according to a third embodiment of the invention;

(5) FIG. 4 is a schematic sectioned view of the hopper in FIGS. 1 to 3, in the closed condition; and

(6) FIG. 5 is a schematic view showing a view of the hopper according to FIG. 4, in the opened condition.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(7) Referring to the drawings, the water-abrasive suspension cutting facility which is shown in FIG. 1 comprises a high-pressure source in the form of a high-pressure pump 2 which is connected to an exit nozzle 6 via a high-pressure region or a high-pressure conduit 4. The high-pressure pump 2 provides the water as a carrier fluid at high pressure, wherein the pressure can amount to 2500 bar or more. The high-pressure conduit 4 divides into two parts, specifically a main branch 8 and an auxiliary branch 10. The main branch 8 runs directly from the high-pressure pump 2 to the exit nozzle 6, whereas the auxiliary branch 10 branches from this main branch 8 and forms a bypass which runs through a pressure container 12. An abrasive agent, e.g. a mineral abrasive agent such as garnet sand, corundum, olivines or river sand is located in the pressure container 12. A mixing between abrasive agent and water occurs when the pressure container 12 is subjected to through-flow, so that the water entrains or carries along the abrasive agent, which is to say flushes it out of the pressure container 12. The auxiliary flow 8 at the exit side of the pressure container 12 runs into the main flow 8 again, at a mixing point 14 which is situated upstream of the exit nozzle 6, and thus this auxiliary flow admixes the abrasive agent carried along out of the pressure container 12 to the main flow, so that the final suspension which the exits outwards out of the exit nozzle 6 is formed at the mixing point 14. A valve which is not represented here can be provided in the auxiliary branch 10, in order to disconnect the auxiliary branch 10, by which means the feed of abrasive agent to the water flow can be switched off.

(8) It is necessary to fill the pressure container 12 again in running operation, for a continuous operation of the facility, since the pressure container 12 is only capable of receiving a certain quantity of abrasive agent. According to the invention, an abrasive agent feed lock 16 is provided for this. This lock comprises a lock chamber 18 which consist of a run-in region 20 as well as an intermediate container 22. The lock chamber 18 is arranged vertically above the pressure container 12 and is separated from this pressure container by an exit-side shut-off element in the form of an exit-side ball cock 24. The lock chamber 18 at the upper end comprises an entry-side ball cock 26 which forms a entry-side shut-off element. A hopper 28 which is described in more detail by way of FIGS. 4 and 5 is arranged vertically above the entry-side ball cock 26. Moreover, a suction device 30 which here comprises a cylinder 32 with a piston 34 which is linearly movable in this connects to the inlet region 20 of the lock chamber 18. The piston 34 is fixedly connected to a drive piston 36 which is linearly movable in a drive cylinder 38 connecting axially onto the cylinder 32.

(9) Moreover, a pressure conduit 40 which branches from the high-pressure conduit 4, in this case from the auxiliary branch 10, runs out into the lock chamber 18. A first pressure compensation valve 42 is arranged in the pressure conduit 40. The lock chamber 18 is moreover connected to a drain conduit 44, in which a second pressure compensation valve 46 is arranged and which runs out into a pressureless run-off 48 downstream of the second pressure compensation valve 46.

(10) A first pressure sensor 50 is arranged on the auxiliary branch 10, and a second pressure sensor 52 on the lock chamber 18. The pressure conduit 4 moreover comprises an accumulator in the form of a pressure accumulator 54.

(11) In the example represented in FIG. 1, a hydraulic drive for the piston 34 of the suction device 30 is provided, wherein this drive is formed by the drive cylinder and the drive piston 36. For this, the drive cylinder 38 at a first side of the drive piston 36 which faces the piston 34 is connected to the high-pressure conduit 4 via a valve 56. Accordingly, the drive cylinder 38 at a second side of the drive piston 36 which is away from the piston 34 is likewise connected to the high-pressure conduit 4 via a further valve 58. A drain valve 60 is moreover arranged at the connection of the valve 56 to the drive cylinder 38. Accordingly, a drain valve 62 is arranged at the connection of the valve 58 to the drive cylinder 38. A check valve 64, 66 is moreover arranged at the exit side of the valves 56 and 58.

(12) A reduced pressure can be produced in the lock chamber 18 when the piston 34 in the cylinder 32 is moved away from the lock chamber 18, i.e. to the drive cylinder 38. This reduced pressure has the effect that with an opened, entry-side ball cock 26, abrasive agent is sucked out of the hopper 28 into the run-in region 20 in the lock chamber 18, by way of a reduced pressure, additionally to the acting gravitational force. The drain valve 62 is opened and the valve 56 simultaneously opened, in order to be able to accordingly move the piston 34 for this, so that the drive piston 36 at its side facing the piston 34 is subjected to pressure and is thus moved in a direction, in which it, together with the piston 34, moves away from the lock chamber 18. Water is sucked out of the lock chamber 18 and a reduced pressure arises in the lock chamber 18, due to the fact that the region of the cylinder 32 which faces the lock chamber 18, i.e. the run-in region 20 of this lock chamber, is connected to this run-in region 20.

(13) The valve 56 is closed, in order to be able to move the piston 34 back in the direction of the lock chamber 18. The drain channel 62 is likewise closed. Conversely, the drain valve 60 and the valve 58 are opened, so that the side of the drive piston 36 which is away from the piston 34 is subjected to pressure, and the drive piston 36 and the piston 34 are hence moved back in the opposite direction.

(14) As a whole, the filling procedure of the pressure container 12 with abrasive agent and according to the invention now takes place as follows. The interior of the lock chamber 18 is firstly relieved from existing residual pressure by way of a brief opening of the second pressure compensation valve 46, wherein fluid flows from the run-in region 20 via the drain conduit 44 into the run-off 48. The pressure compensation valve 46 is thereafter closed again. The piston 34 is moreover moved by the already described drive, into a first end-position, in which it is situated at the end of the cylinder which faces the lock chamber 18, i.e. the end which is away from the drive cylinder 38. I.e. in this condition, the volume of the cylinder 32 which faces the lock chamber 18 and is connected to this is minimal. Given a closed pressure compensation valve 46, the entry-side ball cock 26 is opened with this movement of the piston 34. Thereby, excess water is pressed out of the lock chamber 18 through the entry-side ball cock 26, as described below by way of FIGS. 4 and 4, into the hopper. As explained by way of FIGS. 4 and 5, the exit of the hopper 28 is subsequently opened, so that abrasive agent can enter from the hopper 28 into the run-in region 20 of the lock chamber 18 on account of gravity. The drive piston 36 is moved to the end of the drive cylinder 38 which is away from the cylinder 32, by way of opening the drain valve 62 and the valve 56, in order to assist or to accelerate this entry of abrasive agent. Thereby, the piston 34 is co-moved, so that the volume of the cylinder 32 which faces the run-in region 20 of the lock chamber 18 and is connected to this, enlarges. A reduced pressure is produced in the lock chamber 18 by way of this, on account of which reduced pressure the abrasive agent is additionally sucked out of the hopper 28. The movement of the drive piston 36 as well as of the piston 34 is stopped by way of closure of the valve 56 and the drain valve 62 when the lock chamber 18 has been filled with abrasive agent to a sufficient extent, and the entry-side ball cock 26 of the lock chamber 18 is closed.

(15) The drive cylinder is subsequently subjected to pressure by way of opening the valve 58, such that the drive piston 36 together with the piston 34 is moved forwards, which is to say is moved towards the lock chamber 18, so that the volume in the cylinder 32 and which faces the lock chamber 18 reduces in size. The piston 34 therefore contributes to the pressure build-up in the inside of the lock chamber 18. The first pressure compensation valve 42 is moreover opened, by which means the lock chamber 18 is subjected to the pressure in the high-pressure conduit 4 or in the high-pressure region. I.e., an essentially complete pressure compensation between the high-pressure conduit 4 and the lock chamber 18 takes place. This is monitored by the pressure sensors 50 and 52. A pressure accumulator 54 is present at the high-pressure conduit 4, in order with this pressure compensation to minimize the pressure drop in this. The exit-side ball cock 24 of the lock chamber 18 is opened when a pressure compensation, i.e. the same pressure in the auxiliary branch 10 and in the lock chamber 18 is detected by the pressure sensors, i.e. after the effected pressure compensation, by which means abrasive agent is transferred from the lock chamber 18, i.e. from the intermediate container of the lock chamber 18, into the pressure container 12 due to gravity. The pressure compensation valve 42 preferably remains open with this transfer, in order to permit a drainage of the intermediate reservoir 22 with its emptying. This means that carrier fluid or water can post-flow into the lock chamber 18 via the pressure compensation valve 42 as well as via the pressure conduit 40, whilst abrasive agent gets out of the intermediate reservoir 22 through the opened ball cock 24 into the pressure container 12. The exit-side ball cock 24 is closed again after the complete emptying of the abrasive agent out of the lock chamber 18, which can be detected via further sensors, e.g. light barriers, which are not shown here. The pressure compensation valve 42 is thereby also closed.

(16) In the next step, a pressure compensation is effected between the lock chamber 18 and the atmosphere, by way of the valve 56 being opened given a closed valve 58, by which means the drive piston 36 is moved backwards together with the piston 34, which is to say away from the lock chamber 18. The volume of the cylinder 32 which faces the lock chamber 18 enlarges, and the pressure in the lock chamber 18 is relieved. The second pressure compensation valve 46 is subsequently opened to the run-off 48, for the complete pressure compensation. The second pressure compensation valve 46 is closed after this pressure compensation has been effected, and the entry-side ball cock 26 is again opened. The drive piston 36 is subsequently subjected to pressure by way of opening the valve 58 and opening the drain valve 60, such that the piston 34 in the cylinder 32 is moved again into its end position facing the lock chamber 18 and the fluid is thereby pressed out of the cylinder 32 back into the lock chamber 18 and out of this through the opened entry-side ball cock 26 into the hopper 28, as is explained by way of FIGS. 4 and 5. In the next step, the exit of the hopper 28 is again opened, and the filling of the lock chamber 18 begins afresh. The pressure container 12 can therefore be filled again and again with abrasive agent via the lock chamber 18, with continuous operation of the cutting facility.

(17) FIG. 2 shows a second variant of a water-abrasive suspension cutting facility according to the invention, which with regard to essential parts is constructed identically to the facility according to FIG. 1. It is merely the differences which are described hereinafter. Only the valves 56 and 58 are shown in FIG. 2, as a drive for the drive piston 36. However, it is to be understood that usefully the drain valves 60 and 62 as well as the check valves 64 and 66 could also be arranged according to the design according to FIG. 1. In the example represented in FIG. 2, an accumulator in the form of a cylinder accumulator 70 is additionally connected to the drain conduit 44 via a throttle 68. Thereby, the drain conduit 44 is connected via the throttle 68 to a first pressure space 72 of the cylinder accumulator 70. The first pressure space 72 is separated from a second pressure space 76 in the inside of the cylinder accumulator 70 by a longitudinally displaceable piston 74. The second pressure space 76 is connected via a first valve 78 to the pressure conduit 4 and via a second valve 80 to a run-off 82 which is at ambient which is to say atmospheric pressure. With the example represented in FIG. 2, the pressure relief, i.e. the pressure compensation of the lock chamber 18 to the surrounding pressure can be effected in two steps. In the first step, the pressure compensation is effected via the cylinder accumulator 70, by way of the second valve 80 which forms a drain valve being opened to the run-off 82. This permits fluid to flow through the throttle 68 into the first pressure space 72, and the piston 74 to move in the direction of the second pressure space 76, so that the second pressure space 76 is reduced in size. A remaining residual pressure in the inside of the lock chamber 18 can then be reduced via the second pressure compensation valve 76 in the manner described by way of FIG. 1. The first valve 78 is opened in the closed condition of the second valve 80, in order to move the piston 74 back in the cylinder accumulator 70, so that the second pressure space 76 is subjected to fluid at high pressure, from the high-pressure conduit 4, and the piston 74 is therefore moved back to the first pressure space 72, by which means the second pressure space 72 is reduced in size. A pressure increase in the lock chamber 18 is therefore achieved given a closed ball cock 26. This pressure increase is effected after filling the lock chamber 18 and closure of the ball cock 26, before the further complete pressure compensation by way of opening the pressure compensation valve 42, as has been described above.

(18) A third embodiment of the invention is shown in FIG. 3. This embodiment essentially corresponds to the embodiment shown in FIG. 2, with the single difference that a separate pneumatic drive via pneumatic connections 84 and 86 on the drive cylinder 38 is provided for the drive of the piston 34 of the suction device 30. The pneumatic connections 84 and 86 are subjected to pressure according to the preceding description of the hydraulic variant, in order to move the drive piston 36 together with the piston 34. Accordingly, a separate pneumatic control system is connected to the pneumatic connections 84 and 86, and this system can preferably applied also when other elements of the facility, in particular valves, for example the pressure compensation valves 42 and 46, are pneumatically actuated.

(19) The function of the hopper 28 is described in more detail by way of FIGS. 4 and 5. The hopper 28 at its lower end comprises an exit 88, which as described above is arranged above the entry-side ball cock 26 of the lock chamber 18. The hopper 18 on operation is filled with water 90 and abrasive agent 92, so that the abrasive agent 92 enters into the lock chamber 18 in the wet condition, so that a transfer of air into the lock chamber 18 is prevented.

(20) The inlet of the abrasive agent into the lock chamber 18 is not solely controlled by the entry-side ball cock 26, but additionally via a closure element 94 in the hopper 28. The closure element 94 at its lower end comprises a closure plug 96 which is configured such it can come into sealed engagement with the inner side of the run-in funnel or hopper 28, in a manner surrounding the exit 88, as is shown in FIG. 4. No abrasive agent 92 can enter into the exit 88 in this condition. Additionally, the closure element 94 however comprises a tube 98 which extends through the closure plug 96 to the exit 88 and comprises a lower opening 100 at its lower end. In the opposite direction, the tube 98 extends from the closure plug 96, upwards above the water level 102, up to a pneumatic cylinder 104 arranged on the upper side of the hopper 28. The tube 58 is vertically movable via the pneumatic cylinder 104, so that, as is shown in FIG. 5, it together with the closure plug 96 can be moved into a vertical upper position, in which the closure plug 96 is remote from the inner wall of the hopper 28, so that an annular gap 106 is realized, through which gap the abrasive agent 92 can flow into the exit 88. It is to be understood that any other suitable linear drive could be applied for moving the tube 98 with the closure plug 96, i.e. for moving the closure element 94, in the vertical direction, instead of a pneumatic drive via the pneumatic cylinder 104.

(21) Apart from the lower opening 100, the tube 98 comprises an upper opening 108 which runs out at the outer periphery of the tube 98. The upper opening 108 is situated above the filling level, i.e. the maximal filling level 110 for the abrasive agent 92. This abrasive agent 92 is prevented from being able to get through the upper opening 108 into the exit 88, in the closed condition of the hopper 28 which is shown in FIG. 4. The exit 88 in this condition is closed for the abrasive agent 92 and can only be opened by way of vertically lifting the closure element 94. However, it is simultaneously open to water which flows from below out of the lock chamber 18 through the entry-side ball cock 26 on moving back the piston 34. I.e. this water which can be displaced out of the lock chamber 18 on moving back the piston 34 and, as the case may be, the piston 74, can enter into the lower opening 100 of the tube 98 and exit through the upper opening 108 above the abrasive agent 92 into the hopper 28.

(22) The tube 98 moreover has a further function, specifically for the entry-side ball cock 26 being able to be flushed before the closure of this, in order to remove abrasive agent out of the ball cock 26. For this, the abrasive agent feed is interrupted by way of lowering the closure element 94, before the end of the suction movement of the piston 34. Then however, a reduced pressure continues to exist in the lock chamber 18 on account of the further suction movement of the piston 34, so that water is sucked from the hopper via the upper opening 108, through the tube 98 out of the lower opening 100 and flows through the still opened ball cock 26. Only after this flushing procedure is the ball cock 26 then closed, as has been described for the filling procedure by way of FIGS. 1-3.

(23) Sensors for monitoring the water level 102 as well as the filling level 110 of the abrasive agent 92, and which are not shown here can be additionally arranged on the hopper 28, in order to be able to automatically refill water and abrasive agent. These e.g. can be light barriers. Further filling level sensors, for example in the form of light barriers can be arranged on the intermediate container 22 and well as the pressure container 12. One can detect when the pressure container 12 must be filled, by way of filling level sensors on this container. One can detect when the intermediate container 22 is completely emptied via filling level sensors on this container, so that the lower ball cock 24 can be closed again. One can also detect when the intermediate container 22 is adequately filled with abrasive agent, before the abrasive agent feed from the hopper 28 is interrupted. The complete filling procedure can therefore be automated via a control device.

(24) While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.