EP3600765B1 - Water abrasive suspension cutting system and method for water abrasive suspension cutting - Google Patents

Description

The present disclosure relates to a water-abrasive suspension cutting system having the features specified in the preamble of claim 1 and a method for water-abrasive suspension cutting according to the preamble of claim 10. Such a cutting system and such a method are from document EP 1 208 944 A known.

Water-abrasive suspension cutting systems are used to cut materials using a high-pressure water jet to which an abrasive is added. Water-abrasive suspension cutting systems are to be distinguished from water-abrasive injection cutting systems, in which the abrasive is first introduced into the already very strongly accelerated water in or at an outlet nozzle. In water-abrasive suspension cutting systems, the water under high pressure is first mixed with the abrasive and then the water-abrasive suspension is accelerated in the outlet nozzle. With water-abrasive injection cutting systems, there is no problem of mixing the abrasive with the water under high pressure, since the abrasive is only fed in at the outlet nozzle, but the abrasive-water ratio in water-abrasive injection cutting systems is severely limited and thus its cutting power. In addition, air inclusions in water-abrasive injection cutting systems lead to a reduction in cutting performance due to ineffective acceleration of the abrasive particles when sucked into the water jet and high air content in the cutting jet. With water-abrasive suspension cutting systems, on the other hand, the abrasive medium-water ratio can be selected higher and a higher cutting force can be achieved because the water is mixed under high pressure with the abrasive in a controlled manner upstream of the exit gland without entrapping air. For example, part of the water flow can be guided through an abrasive agent container, which is designed as a pressure container. Such a system is z. B. from the EP 1 199 136 known. A technical challenge with these systems is topping up the abrasive, since the system has to be shut down for this, the abrasive agent tank must be depressurized and only then can it be filled. In industrial applications, however, continuous cutting is often desired, in which the plant does not have to be shut down to fill the abrasive.

the EP 2 755 802 B1 and WO 2015/149867 A1 describe lock solutions to ensure continuous operation of the system. However, due to the particularly high pressures of sometimes over 2,000 bar, the cyclic pressurization and depressurization of a lock chamber is a technical challenge. In particular, it is difficult to set a desired mixing ratio between water and abrasive in the cutting jet with the known systems.

The water-abrasive suspension cutting system disclosed herein according to independent claim 1 and the water-abrasive suspension cutting method disclosed herein according to independent claim 10 has the advantage over the known solutions that a desired mixing ratio between water and abrasive in the cutting jet is targeted can be set and changed as required. Advantageous refinements of the disclosure are specified in the dependent claims, the following description and the drawings.

• einer Hochdruckquelle zum Bereitstellen von Wasser unter Hochdruck,
• einer mit der Hochdruckquelle verbundenen Hochdruckleitung, und
• einem Druckbehälter zum Bereitstellen einer unter Hochdruck stehenden Abrasivmittelsuspension, wobei

der Druckbehälter über eine regelbare Drossel mit der Hochdruckleitung fluidverbunden ist, wobei die Drossel eingangsseitig vom Druckbehälter angeordnet ist und dazu eingerichtet ist, abhängig von mindestens einer Regelgröße den Zufluss in den Druckbehälter aus der Hochdruckleitung zu regeln.According to a first aspect of the present disclosure, a water-abrasive suspension cutting system is provided with

• a high-pressure source for providing water under high pressure,
• a high pressure line connected to the high pressure source, and
• a pressure vessel for providing a high-pressure abrasive suspension, wherein

the pressure vessel is in fluid communication with the high-pressure line via a controllable throttle, the throttle being arranged on the inlet side of the pressure vessel and being set up to regulate the inflow into the pressure vessel from the high-pressure line as a function of at least one controlled variable.

With this system, a desired mixing ratio between water and abrasive in the cutting jet can be set. Clear, non-abrasive water flows through the adjustable throttle located on the inlet side of the pressure vessel, which means that it wears considerably less than if it were located on the outlet side. The controllable throttle can also be referred to as a control valve, which can preferably completely shut off the inflow if necessary.

Optionally, a shutoff valve may be positioned downstream or upstream of the restrictor to completely stop the flow of abrasive from the pressure vessel. For example, a sensor signal can be used to signal the shut-off valve to shut off the pressure vessel from the high-pressure line. If necessary, this can take place when a minimum filling level is reached, which should not be fallen below.

Optionally, the at least one controlled variable can have a sensor signal and/or an operating parameter of the high-pressure source. The controlled variable can have several parameters, combinations of parameters or have calculations from one or more parameters. In this sense, “having” means that the at least one controlled variable depends on the sensor signal or the parameter or that the sensor signal or the parameter is included in the controlled variable.

Optionally, the at least one controlled variable has an abrasive agent flow from the pressure vessel or a parameter that is characteristic of an abrasive agent flow from the pressure vessel. For example, the system can have a first level sensor for signaling at least a first level of abrasive in the pressure vessel. The at least one controlled variable can then have a change in the first fill level over time.

Optionally, the system can have a first fill level sensor for signaling at least a first fill level of abrasive in the pressure vessel and a second fill level sensor for signaling at least a second fill level of abrasive in the pressure vessel, wherein the at least one controlled variable can have a time difference between the first fill level and the second fill level . For example, the fill level sensors can be ultrasonic sensors or optical sensors that are arranged at different vertical positions on the pressure vessel and can signal a specific fill level. If the geometry of the pressure vessel is known and the vertical distance between the first and the second level sensor is known, the time difference for an abrasive removal flow is characteristic, according to which the inflow to the pressure vessel can be regulated.

Optionally, the system can have an abrasive agent flow sensor arranged on the outlet side of the pressure vessel for signaling an abrasive agent removal flow, according to which the inflow to the pressure vessel can be regulated. The abrasive medium flow sensor can, for example, run through an abrasive medium line on the outlet side Count abrasive particles or otherwise measure abrasive flow. This can take place, for example, optically, inductively using ferromagnetic markers in the abrasive or by measuring structure-borne noise.

Optionally, the control variable can have a speed and/or power or current consumption of the high-pressure source. The water flow through the high-pressure line can be inferred from the rotational speed and/or power or current consumption of the high-pressure source, which can also determine the mixing ratio in the cutting jet. Therefore, preferably these or other operating parameters of the high-pressure line can also be included in the at least one controlled variable. Alternatively or additionally, a flow sensor can measure or signal a water flow through the high-pressure line, so that this can be included in the at least one controlled variable.

• Bereitstellen von Wasser unter Hochdruck in einer Hochdruckleitung mittels einer Hochdruckquelle,
• Bereitstellen einer unter Hochdruck stehenden Abrasivmittelsuspension in einem Druckbehälter,
• Schneiden eines Materials mittels eines Hochdruckstrahls, der zumindest teilweise die Abrasivmittelsuspension enthält, unter Entnahme der Abrasivmittelsuspension aus dem Druckbehälter, und
• Regeln eines Zuflusses in den Druckbehälter aus der Hochdruckleitung mittels einer eingangsseitig mit dem Druckbehälter fluidverbundenen und regelbaren Drossel in Abhängigkeit von einer Regelgröße.

According to a second aspect of the present disclosure, there is provided a method for water-abrasive suspension cutting, comprising the steps:

• providing high-pressure water in a high-pressure line by means of a high-pressure source,
• Providing an abrasive suspension under high pressure in a pressure vessel,
• cutting a material by means of a high-pressure jet which at least partially contains the abrasive suspension, while removing the abrasive suspension from the pressure vessel, and
• Regulating an inflow into the pressure vessel from the high-pressure line by means of a throttle that is fluidly connected to the pressure vessel on the inlet side and can be regulated as a function of a controlled variable.

Optionally, the regulation is carried out depending on a sensor signal and/or an operating parameter of the high-pressure source. For example, the regulation can be performed depending on a flow of abrasive from the pressure vessel. Alternatively or additionally, the regulation can be carried out as a function of a change over time in a first fill level of abrasive in the pressure vessel, with the first fill level being signaled by a first fill level sensor.

Optionally, the regulation can take place as a function of a time difference between a first filling level of abrasive in the pressure vessel and a second filling level of abrasive in the pressure vessel, the first filling level being signaled by a first filling level sensor and the second filling level being signaled by a second filling level sensor. As an alternative or in addition, the regulation can be carried out as a function of a flow of abrasive medium, with the flow of abrasive medium being signaled by an abrasive medium flow sensor arranged on the outlet side of the pressure vessel. Alternatively or additionally, the regulation can also take place as a function of a speed or a power or current consumption of the high-pressure source.

• Fig. 1 ein schematisches Schaltbild eines ersten Ausführungsbeispiels der hierein offenbarten Wasser-Abrasiv-Suspensions-Schneidanlage;
• Fig. 2 ein schematisches Schaltbild eines zweiten Ausführungsbeispiels der hierein offenbarten Wasser-Abrasiv-Suspensions-Schneidanlage;
• Fig. 3 ein schematisches Schaltbild eines dritten Ausführungsbeispiels der hierein offenbarten Wasser-Abrasiv-Suspensions-Schneidanlage;
• Fig. 4 ein schematisches Schaltbild eines vierten Ausführungsbeispiels der hierein offenbarten Wasser-Abrasiv-Suspensions-Schneidanlage;
• Fig. 5 ein schematisches Schaltbild eines fünften Ausführungsbeispiels der hierein offenbarten Wasser-Abrasiv-Suspensions-Schneidanlage;
• Fig. 6a-c schematische Teilschaltbilder dreier unterschiedlicher Ausführungsformen einer Förderhilfe der hierein offenbarten Wasser-Abrasiv-Suspensions-Schneidanlage;
• Fig. 7a-c schematische Teilschaltbilder dreier unterschiedlicher Ausführungsformen einer Abrasivmittelstromsteuerung der hierein offenbarten Wasser-Abrasiv-Suspensions-Schneidanlage;
• Fig. 8-12 schematische Schaltbilder fünf unterschiedlicher Ausführungsformen einer Abrasivmittelnachfuhreinrichtung der hierein offenbarten Wasser-Abrasiv-Suspensions-Schneidanlage;
• Fig. 13 ein schematisches Ablaufdiagramm eines Verfahrens zum Wasser-Abrasiv-Suspensions-Schneiden;
• Fig. 14 Druck-Zeit-Diagramme in einer Schleusenkammer, in einem Druckspeicher und in einer Hochdruckleitung gemäß der hierein offenbarten Wasser-Abrasiv-Suspensions-Schneidanlage;
• Fig. 15a-b Querschnitte in einer xz-Ebene durch ein Nachfüllventil in zwei verschiedenen Offnungsstellungen gemäß der hierein offenbarten Wasser-Abrasiv-Suspensions-Schneidanlage;
• Fig. 16a-b Querschnitte in einer xz-Ebene durch ein Nachfüllventil in zwei verschiedenen Schließstellungen gemäß der hierein offenbarten Wasser-Abrasiv-Suspensions-Schneidanlage;
• Fig. 17a-b Querschnitte in einer yz-Ebene durch ein Nachfüllventil in Schließstellung gemäß zweier unterschiedlicher Wasser-Abrasiv-Suspensions-Schneidanlagen;
• Fig. 18a-b perspektivische Ansichten auf ein Nachfüllventil gemäß der hierein offenbarten Wasser-Abrasiv-Suspensions-Schneidanlage; und
• Fig. 19a-b Querschnitte durch ein Absperrventil in Form eines Nadelventils gemäß zwei verschiedener Wasser-Abrasiv-Suspensions-Schneidanlagen; in einer Öffnungsstellung.

The disclosure is explained in more detail below with reference to exemplary embodiments illustrated in the drawings. Show it:

• 1 a schematic circuit diagram of a first exemplary embodiment of the water-abrasive suspension cutting system disclosed herein;
• 2 a schematic circuit diagram of a second embodiment of the water-abrasive suspension cutting system disclosed herein;
• 3 a schematic circuit diagram of a third embodiment of the water-abrasive suspension cutting system disclosed herein;
• 4 a schematic circuit diagram of a fourth exemplary embodiment of the water-abrasive suspension cutting system disclosed herein;
• figure 5 a schematic circuit diagram of a fifth exemplary embodiment of the water-abrasive suspension cutting system disclosed herein;
• Fig. 6a-c schematic partial circuit diagrams of three different embodiments of a conveying aid of the water-abrasive suspension cutting system disclosed herein;
• Fig. 7a-c schematic partial circuit diagrams of three different embodiments of an abrasive flow control of the water-abrasive suspension cutting system disclosed herein;
• Figures 8-12 schematic circuit diagrams of five different embodiments of an abrasive agent supply device of the water-abrasive suspension cutting system disclosed herein;
• 13 a schematic flowchart of a method for water-abrasive suspension cutting;
• 14 Pressure-time diagrams in a lock chamber, in a pressure accumulator and in a high-pressure line according to the water-abrasive suspension cutting system disclosed herein;
• Fig. 15a-b Cross sections in an xz plane through a refill valve in two different opening positions according to the water-abrasive suspension cutting system disclosed herein;
• Fig. 16a-b Cross sections in an xz plane through a refill valve in two different closed positions according to the water-abrasive suspension cutting system disclosed herein;
• Fig. 17a-b Cross-sections in a yz plane through a refill valve in the closed position according to two different water-abrasive suspension cutting systems;
• Fig. 18a-b perspective views of a refill valve according to the water-abrasive suspension cutting system disclosed herein; and
• Fig. 19a-b Cross sections through a shut-off valve in the form of a needle valve according to two different water-abrasive suspension cutting systems; in an open position.

In the 1 The water-abrasive suspension cutting system 1 shown has a high-pressure source 3 that provides water in a high-pressure line 5 at a high pressure po of about 1,500 to 4,000 bar. The high-pressure line 5 is connected to an outlet nozzle 7, from which the water, which is under high pressure, emerges in a jet 9 at very high speed. So that the jet 9 can be used effectively as a cutting jet for cutting material, the high-pressure line 5 is branched in such a way that at least part of the flow through the high-pressure line 5 is guided through a pressure container 11, in which a water-abrasive suspension 13 is located . The supply of the water-abrasive suspension 13 to the outlet nozzle can be switched on and off via a shut-off valve 15 . The proportion of the water-abrasive suspension 13 in the beam 9 can be adjusted via a throttle 17 by the flow rate is throttled in the secondary branch of the high-pressure line 5 that is routed through the pressure vessel 11 . The throttle 17 can be regulated, with a signal characteristic of the abrasive agent removal flow, which can be obtained from a sensor or an available operating parameter, being used as a controlled variable for regulating the opening of the throttle 17 (see Fig. 7a-c ). The throttle 17 can preferably completely shut off the inflow into the pressure vessel 11, so that the shut-off valve 15 can be dispensed with.

During cutting, the water-abrasive suspension 13 is removed from the pressure vessel 11 and water is supplied under high pressure, so that the abrasive agent in the pressure vessel 11 is consumed. Therefore, the pressure vessel 11 must be refilled continuously or sequentially with abrasive. For this purpose, a refill valve 19 in the form of a ball valve is arranged above the pressure vessel 11 . The refill valve 19 connects a sluice chamber 21 arranged above the refill valve 19 to the pressure vessel 11. A filling valve 23 is in turn arranged above the sluice chamber 21 and connects a refill funnel 25 arranged above the sluice chamber 21 to the sluice chamber 21. The filling valve 23 can be configured essentially identically to the refill valve 19 in the form of a ball valve.

The refill funnel 25 is not under pressure, so that dry, moist or wet abrasive or a water-abrasive suspension can be filled in from above (see Fig Figures 8-12 ). This can be, at least in part, an abrasive agent that is reprocessed from the cutting jet 9 and that is transported via a conveyor device (see Figures 8-12 ) in dry, wet, frozen, pelleted or suspended form Form can be filled into the refill funnel 25 from above. When the refill valve 19 is closed, the sluice chamber 21 can be depressurized at times. For example, a pressure in the sluice chamber 21 can be released into an outlet 29 via a pressure release valve 27 in the form of a needle valve. When the lock chamber 21 is depressurized, the filling valve 23 can be open, so that abrasive material falls from the refill funnel 25 into the lock chamber 21 . This gravitational filling of the lock chamber 21 with abrasive can be supported and accelerated by a pump 31. The pump 31 can be connected to the lock chamber 21 on the suction side and to the refill funnel 25 on the pressure side. The pump 31 can thus suck abrasive into the lock chamber 21. This is especially useful when abrasive media is clogged in the tapered lower area of the refill funnel 25 or on the filling valve 23 . By sucking the abrasive down by the pump 31, a clog can be cleared or a clog can be prevented from occurring. So that the pump 31 does not have to be designed for high pressure, it is advantageous if the pump 31 can be shut off from the sluice chamber 21 by means of a pump shut-off valve 33 in the form of a needle valve. The pump shut-off valve 33 can be designed so that it can be flushed through in order to flush the valve seat and the valve body, for example in the form of a valve needle, free of abrasive (see FIG Figures 19a-b ). This ensures, on the one hand, that the pump shut-off valve 33 closes tightly and reduces material wear in the valve. The pump 31 can be largely protected from abrasives by means of an upstream filter and/or separator (both not shown).

The pump shut-off valve 33 is only opened when the lock chamber 21 is already depressurized. Therefore, for the pump shut-off valve 33, a first embodiment of the needle valve according to Figure 19a be used where a side flush inlet and an opposite lateral flushing outlet is provided. For the pressure relief valve 27, on the other hand, the second embodiment of the needle valve according to FIG Figure 19b more advantageously, in which a non-return valve is provided at the flushing inlet. Since the pressure release valve 27 is opened at high pressure, the check valve prevents pressure release towards the flushing inlet. The scavenging outlet can open into the outlet 29 so that both the pressure release and the rinsing agent outlet take place exclusively towards the outlet 29 and not towards the rinsing inlet.

As soon as the sluice chamber 21 is filled with 1 kg of abrasive, for example, the filling valve 23 can be closed. In addition, the pressure relief valve 27 and the pump shut-off valve 33 are now closed. The lock chamber 21 has a pressure input 35 in a lower area, via which the lock chamber 21 can be pressured. The Bedruckungseingang 35 is in the embodiment 1 connected via a pressure valve 37 in the form of a needle valve to a pressure accumulator 39 and via throttles 41, 42 to the high-pressure line 5 in a lockable manner. The pressure accumulator 39 has two pressure accumulator units in the form of spring accumulators, which are connected in parallel to the input of the pressure valve 37. The pressure accumulator 39 is connected to the high-pressure line 5 via the throttle 41 . The throttles 41, 42 can be static, for example in the form of pinholes, or adjustable or controllable. If the throttles 41, 42 can be adjusted to a degree at which the connection between the high-pressure line 5 and the pressurization inlet 35 can be completely shut off, the pressurization valve 37 can possibly be dispensed with. The accumulator 39 is fully pressurized before the lock chamber 21 is pressurized. As soon as the pressure valve 37 is opened, the pressure from the accumulator 39 discharges into the sluice chamber 21 and thus quickly pressurizes it to about 40% of the high pressure po that is provided in the high-pressure line 5 as the nominal high pressure from the high-pressure source 3 . Through this rapid partial printing, a pressure pulse is introduced from below into the sluice chamber 21, which loosens the abrasive. This is advantageous for the later discharge of the abrasive into the pressure vessel 11. Since the high-pressure line 5 is also connected to the sluice chamber 21 via the throttle 41 , a throttled, ie slower, pressurization through the high-pressure line 5 also takes place in parallel with the opening of the pressurization valve 37 . As soon as the pressure accumulator 39 has been depressurized, the remaining pressure required in the lock chamber 21 of about 60% of the nominal high pressure po is built up exclusively via the throttled, ie slower, pressure from the high-pressure line 5 . Thus, the amplitude of the pressure drop in the high-pressure line 5 is kept to a minimum.

in the in 1 First embodiment shown, the accumulator 39 is pressurized again immediately from the moment in which it has discharged itself. In this case, the high-pressure line 5 pressurizes both the sluice chamber 21 with the residual pressure and the pressure accumulator 39. This is particularly advantageous if the pressure loading of the pressure accumulator 39 is so time-consuming that the refilling passage rate depends on the pressure loading time of the pressure accumulator 39.

in the in 2 shown second embodiment, the pressure accumulator 39 can be shut off with a pressure accumulator valve 43 in the form of a needle valve. At the moment when the pressure accumulator 39 has been discharged, the pressure accumulator valve 43 can be shut off so that the high-pressure line 5 is not additionally burdened with the pressure loading of the pressure accumulator 39 while the lock chamber 21 is being pressurized. Such a load could cause a pressure drop in the high-pressure line 5, which could have a negative impact on the cutting performance at the outlet nozzle 7. It is therefore advantageous to open the pressure accumulator valve 43 only when the lock chamber 21 is fully pressurized and the Bedruckungsventil 37 is closed, so that the pressure accumulator 39 can be pressurized via the throttle 41 from the high-pressure line 5. This is particularly advantageous when the pressure charging of the pressure accumulator 39 is not so time-consuming that the refilling passage rate depends on the pressure charging time of the pressure accumulator 39 . The filling of the sluice chamber 21 and the refilling of the pressure vessel 11 can usually take longer than the pressure charging of the pressure accumulator 39. The throttle 41 can be set in such a way that the pressure accumulator 39 is pressurized as slowly as possible, but still fast enough so that before the next pass to pressurize the lock chamber 21 of the pressure accumulator 39 is fully pressurized.

In a third embodiment according to 3 the pressure accumulator 39 is dispensed with entirely and the lock chamber 21 is pressurized exclusively via the throttle 41 from the high-pressure line 5 . This is advantageous when the high-pressure source 3 reacts so quickly to an initial pressure drop, for example via a servo pump control, and can adapt the pump output quickly enough that a large amplitude of a pressure drop does not occur in the first place. An initial drop in pressure can be communicated to the high-pressure source 3 via pressure sensors, so that the high-pressure source 3 can quickly counteract a further drop in pressure with an increase in output or speed. The initial pressure drop can already be mitigated via the throttle 41, so that there is never a pressure drop that significantly impairs the cutting performance.

As soon as the sluice chamber 21 is fully pressurized, the refill valve 19 can be opened so that abrasive media can flow out of the sluice chamber 21 through the refill valve 19 into the pressure vessel 11 by gravity or by gravity, in order to fill the latter to refill. A conveying aid 45, for example in the form of a pump, is preferably provided, which is connected to the pressure vessel 11 on the suction side and to the lock chamber 21 on the pressure side. The conveying aid 45 supports or generates the abrasive agent flow from the lock chamber 21 downwards into the pressure vessel 11. It can prevent or solve blockages of abrasive agent and accelerate the refilling process caused by or assisted by gravity. In contrast to the pump 31 on the refill funnel 25, the conveying aid 45 on the pressure vessel 11 works with water at the nominal high pressure po. It must therefore be designed for high-pressure operation. For example, as in Figure 6b shown, only have an inductively driven impeller in high pressure, so that the number of moving parts that are under high pressure is minimized. A conveying aid shut-off valve 47 is arranged between the conveying aid 45 and the lock chamber 21, the conveying aid shut-off valve 47 in the form of a needle valve being able to shut off the pump 47 from the lock chamber 21 when the lock chamber 21 is not or not fully pressurized. Preferably, the pumping aid shut-off valve 47 is a flushable needle valve according to FIG Figure 19b with a non-return valve on the flushing inlet since it is actuated under high pressure.

Fig. 6a-c show various alternative embodiments for the conveying aid 45. The conveying aid 45 can, for example, have an impeller driven externally via a shaft (see FIG Figure 6a ) or an inductively driven impeller (see Figure 6b ). The conveying aid 45 can also support the refilling of abrasive into the pressure tank 11 via a piston stroke (see Fig Figure 6c ). The conveying aid 45 can pump or convey continuously or in a time-limited or pulsed manner. It may be sufficient if the abrasive agent flow into the pressure vessel 11 is only supported initially and then continues to run fast enough alone, with the aid of gravity. Alternatively or in addition the flow of abrasive into the pressure vessel 11 can be supported or generated continuously.

In addition to an upper valve inlet 49 and a lower valve outlet 51 , the refill valve 19 also has a lateral pressure inlet 53 . A valve chamber, in which a movable valve body is located, can be pressurized via the pressure inlet 53 . If the valve chamber is not pressurized, it is possible that when the system is started up, the very high pressures on the valve inlet 49 and the valve outlet 51 press the valve body so hard into the valve seat that the valve body can no longer be moved. Pressure can be equalized in the refill valve 19 via the lateral pressure inlet 53, so that the valve body can be moved after it has been put into operation.

in the in 4 and 5 The fourth or fifth exemplary embodiment shown is provided for flushing the refill valve 19 . For this purpose, a flushing source 55 can be connected to the pressure inlet 53 in a lockable manner (see 4 ). Preferably, three scavenging valves 57, 59, 61 are provided to be able to switch the scavenging on and off or to separate it from the high pressure. A first flushing valve 57 in the form of a needle valve is arranged between the delivery aid 45 and the pressure inlet 53 . A second scavenging valve 59, also referred to here as a scavenging outlet valve 59, is arranged in the form of a needle valve between a lateral scavenging outlet 63 and an outlet 65. A third purge valve 61 in the form of a needle valve is positioned between the purge source 55 and the pressure inlet 53 .

In order to flush the refill valve 19 with water or a mixture of water and washing-up liquid so that a valve chamber of the refill valve 19 can be freed from residues of abrasive, the refill valve 19 is preferably closed. The first purge valve 57 is also closed so that pressure can be released from the pressure inlet 53 without releasing the pressure on the conveying aid 45. The second scavenging valve 59 is opened towards the outlet 65 so that any high pressure that may be present can be released from the valve chamber. If the third flushing valve 61 is now opened, water or a mixture of water and flushing agent flows through the valve chamber to the outlet 65 and thus flushes it free of residues of abrasive. The flushing of the refill valve 19 is preferably carried out as a service procedure when the system 1 is completely depressurized, in order to be able to flush out the valve chamber completely and, if necessary, to be able to move the valve body in the process.

As an alternative to the fourth embodiment according to 4 can according to a fifth embodiment figure 5 a flushing inlet 66 separate from the pressure inlet 53 is provided (see also Fig. 15a-b and 17a-b ). The pressure inlet 53 may be coaxial with and opposed to a servomotor shaft 86 , while the purge inlet 66 and purge outlet 63 may be coaxial and disposed transversely of the servomotor shaft 86 on opposite sides of each other.

The flushing is ended again by closing the three flushing valves 57, 59, 61 in reverse order, ie the third flushing valve 61 is closed first, so that the flushing flow is stopped. The second flushing valve 59 is then closed in order to close off the valve chamber from the outlet 65 . Finally, the first flushing valve 57 can be opened so that the valve chamber is pressurized with high pressure. Printing the valve chamber is advantageous because a valve body in the refill valve 19 can be pressed so hard into a valve seat by the high pressure difference between the valve outlet 51 or valve inlet 49 and the valve chamber that it can no longer be moved. The pressurizing of the valve chamber, on the other hand, creates pressure equalization so that the valve body in the refill valve 19 remains movable.

According to the partial circuit diagrams Fig. 7a-c a preferred regulation of the abrasive removal flow is illustrated. A branch of the high-pressure line 5 is routed through the pressure vessel 11 filled with the abrasive suspension 13 in order to add abrasive to the cutting jet 9 . An extraction point 68 arranged in the lower area of the pressure vessel 11 is connected to the outlet nozzle 7 via an abrasive medium line 70, and a branch of the high-pressure line 5 is routed via a control valve or controllable throttle 17 into an upper area of the pressure vessel 11. Downstream from the pressure vessel 11, the abrasive medium line is reunited with the high-pressure line 5 in front of the outlet nozzle 7, so that the cutting jet contains, for example, a mixing ratio of 1:9 abrasive medium suspension and water. The mixing ratio can be regulated via the throttle or control valve 17 connected to the pressure vessel 11 on the inlet side. When the control valve 17 is in the maximum open position, the flow of abrasive removal is maximum and the mixing ratio is maximum. At minimum open position or closed position (see Fig. 7b or 7c ) of the control valve 17, the abrasive removal flow is minimal or zero and the mixing ratio is correspondingly low or the cutting jet 9 then contains only water.

Now, it is advantageous to measure and control the actual abrasive extraction flow for several reasons. On the one hand, a certain mixing ratio can be optimal for cutting certain materials, workpieces or workpiece sections, in which only as much abrasive is removed as is necessary to achieve the cutting performance. In the case of inhomogeneous workpieces, the cutting performance can be adjusted via the mixing ratio during cutting. On the other hand, the refilling of the pressure vessel 11 with abrasive can be controlled according to the abrasive removal flow so that there is always enough abrasive suspension 13 in the Pressure vessel 11 is present for continuous cutting. In Fig. 7a-c four different fill levels of the abrasive in the pressure vessel 11 are indicated by dashed cones. Two further level cones F ₁ and F ₂ are shown between a maximum level cone F _max and a minimum level cone F _min , with F _max >F ₁ >F ₂ >F _min . It should be pointed out once again at this point that the entire system 1 and in particular the pressure vessel 11 are completely free of air. This means that the level cones are in highly pressurized water. The maximum filling level cone F _max is defined by the fact that further refilling with abrasive into the pressure vessel 11 would result in a back pressure in the refill valve 19 . The minimum filling level cone F _min is defined by the fact that the proportion of abrasive medium in the abrasive medium suspension in the abrasive medium line 70 on the outlet side would decrease if abrasive medium were to be removed further.

As in Figures 7a and 7b shown, level sensors 72, 74, 76 can be arranged on the pressure vessel 11 in order to signal that a level cone has been reached. The level sensors 72, 74, 76 can be, for example, ultrasonic sensors, optical sensors or barriers, electromagnetic sensors or sensors of other types. Here the level sensors 72, 74, 76 are ultrasonic sensors, which can signal that a level cone has been reached via a change in structure-borne noise. An upper filling level sensor 72 can, for example, signal that the filling level cone F ₁ has been reached and can start a timer or define a point in time t ₁ . A lower filling level sensor 74 can, for example, signal that the filling level cone F ₂ has been reached and can stop a timer after Δt or define a point in time t ₂ . A mean abrasive removal flow can be determined as ΔV/Δt or ΔV/(t ₂ −t ₁ ) via the known geometry of the pressure vessel 11 and the vertical spacing of the level sensors 72, 74 . The third bottom level sensor 76 can be the minimum level cone F _min signal and immediately shut off the shut-off valve 15 to prevent the pressure vessel 11 from being sucked dry. According to Figure 7b other operating parameters such as the pump speed of the high-pressure source 3 can also be used to determine the abrasive agent removal flow and its regulation as a controlled variable for the control valve 17 . As in Figure 7c shown, the abrasive medium flow or the mixing ratio can also be determined by means of a corresponding sensor 79 on the abrasive medium line 70 or in front of the outlet nozzle 7 and used as a controlled variable for the control valve 17 .

The level sensors 72, 74 can also be used to control or clock the refill cycles. For example, a filling of the lock chamber 21 can fit above the upper level sensor 72 between the level cone F ₁ and the maximum level cone F _max . If the filling level cone drops below Fi, the upper filling level sensor 72 can trigger filling of the lock chamber 21 so that it is completely filled when the lower filling level sensor 74 signals the filling level cone F ₂ and can thus trigger refilling from the filled lock chamber 21 into the pressure vessel 11. This prevents the level cone from dropping down to the minimum level cone F _min . At least one filling of the lock chamber 21 can also fit as a buffer between the minimum level cone F _min and the level cone F ₂ . As an alternative to triggering the filling of the sluice chamber 21 at a specific fill level, the sluice chamber 21 can always be automatically refilled immediately as soon as the refilling of the pressure vessel 11 is complete. Then refilling from the sluice chamber 21 only needs to be triggered when the level cone F ₂ is reached. The vertical distance between the upper filling level sensor 72 and the lower filling level sensor 74 can be chosen to be relatively short, for example so short that a drop between F ₁ and F ₂ takes less time than a filling process of the lock chamber 21. With a shorter vertical distance, the mean abrasive removal flow ΔV/Δt or ΔV/(t ₂ -t ₁ ) can be determined more frequently and thus more accurately reflect the current abrasive removal flow dV/dt.

Figures 8 to 12 show various ways of adding abrasives in dry, wet, moist, suspended, frozen, pelleted or other form to the refill funnel 25 or directly to the filling valve 23. In 8 a pre-loading container 78 is provided, from which abrasive suspension is conveyed into the refill funnel 25 by means of a pump 80 . When loading the refill funnel 25, water that is displaced by the sinking abrasive can run off via an overflow 82 on the refill funnel.

In 9 a pre-loading container 78 is provided, from which dry powdered or moist lumpy abrasive agent is conveyed into the refill hopper 25 by means of a conveyor screw 84 and/or a conveyor belt 85 . When the refill funnel 25 is being loaded, water that is displaced by the sinking abrasive can also run off here via the overflow 82 on the refill funnel 25 . The abrasive can, for example, be recovered and processed from the waste water of the cutting jet 9 after a cutting process, so that it can be used for a further cutting process. The advantage of this system compared to known water-abrasive injection cutting systems is that such a reprocessed abrasive does not have to be dried and can be filled into the system in a wet lumpy or any form.

In 10 no overflow 82 is provided, but rather a circuit between the refill hopper 25 and the preloading container 78, with the pump 80 driving the circuit for filling the refill hopper 25 with abrasive on the output side of the refill hopper 25. The refill funnel 25 is preferably closed in this case, so that the pump 80 can suck abrasive suspension out of the preloading container 78 . The advantage here is that the pump 80 pumps relatively clean water and not a saturated abrasive suspension as in 8 . As a result, the wear in the pump 80 is reduced. In addition, sucking in the abrasive suspension is less prone to clogging than pressing. As in 11 shown, however, a screw conveyor 84 can also be arranged on the input side of the refill hopper 25 in order to convey abrasive into the refill hopper 25 . This is particularly advantageous when there is no abrasive suspension in the preloading container 78, but rather abrasive as a dry powder or in a wet lumpy form.

The refill funnel 25 can even be dispensed with completely (see 12 ) if the conveying via a screw conveyor 84 or a pump 80 takes place quickly enough and in a controlled manner directly into the filling valve 23. The water displaced by the abrasive when the lock chamber 21 is being filled can be returned from the lock chamber 21 to the refill funnel 25 via the pump shut-off valve 33 . This can also be done with a pump 31 according to FIG Figures 1 to 5 be supported in order to actively suck abrasives into the lock chamber 21 as well.

According to one exemplary embodiment, the abrasive medium is refilled in the pressure vessel 11 in portions and cyclically, while a workpiece to be machined can be cut continuously with the cutting jet 9 . 13 illustrates the process steps over time. In a first step 301 , water is made available under high pressure in the high-pressure line 5 by means of the high-pressure source 3 . This then also provides a pressurized abrasive suspension in the pressure vessel 11 303. A workpiece can then already be cut 305 by means of the high-pressure jet 9, which at least partially contains the abrasive suspension, while removing the abrasive suspension from the pressure vessel 11. Steps 307 to 311 serve to refill the pressure vessel 11 with abrasive in portions and cyclically during continuous cutting 305. First, the unpressurized sluice chamber 21 is filled 307 with abrasive or an abrasive suspension. The pump 31 is then shut off from the sluice chamber 21 308. The sluice chamber is then at least partially pressurized 309 by depressurizing the pressure accumulator 39, and finally the pressure container 11 is refilled 311 with abrasive or an abrasive suspension via the refill valve 19 from the pressurized sluice chamber 21. When refilling 311 the conveying aid 45 is in fluid communication with the pressurized lock chamber 21 via the open conveying aid shut-off valve 47 . After refilling 311, the conveyor aid shut-off valve 47 and the pressure valve 37 and the refill valve 19 are shut off in order to be able to relieve the pressure in the sluice chamber 21 via the pressure relief valve 27 into the outlet 29 for the next filling step.

During the filling 307 of the lock chamber 21 or during the refilling 311 of the pressure vessel 11, the pressure accumulator can be pressurized 313 via the throttle 41 from the high-pressure line 5. Starting at the same time as the pressurization 309 of the lock chamber 21 from the pressure accumulator 39, the lock chamber 21 can at least partially overflow the throttle 41 from the high-pressure line 5 are printed 315. This slow throttled printing 315 from the high-pressure line 5 can last longer than the fast printing 309 by the pressure discharge of the pressure accumulator 39. In other words, the printing 309 of the sluice chamber 21 can A pressure accumulator 39 is depressurized during a first time window A and the lock chamber 21 of the high-pressure line 5 is pressurized 315 during a second time window B, with the first time window A and the second time window B at least partially overlapping, preferably at the beginning.

The loading 309 of the sluice chamber 21 by depressurizing the pressure accumulator can take place so quickly that the abrasive agent in the sluice chamber 21 is loosened by a pressure surge. The sluice chamber is pressurized 309 by discharging the pressure from the pressure accumulator 39, preferably in a lower region of the sluice chamber 21, since any blockages of abrasive are more likely in a lower region than in an upper region.

Optionally, the pressure input 35 of the lock chamber 21 is shut off from the pressure accumulator 39 and/or the high-pressure line 5 during the filling 307 and the refilling 311 . The pressure loading 313 of the pressure accumulator 39 can thus take place during the filling 307 and/or the refilling 311 . In this case, energy can be stored via a spring or fluid compression in the pressure accumulator 39, which can be designed, for example, as a spring or bladder accumulator. The filling 307, the printing 309 and the refilling 311 can take place cyclically while the cutting 305 can be carried out continuously.

Optionally, after the lock chamber 21 has been pressurized 309 , the pressure accumulator 39 can first be shut off by the pressure accumulator 39 being discharged from the high-pressure line 5 by means of the pressure accumulator valve 43 . The pressure accumulator valve 43 can preferably only then be opened again for the purpose of pressurizing the pressure accumulator 39 be when the lock chamber 21 was pressurized via the throttle 41 from the high-pressure line 5.

14 illustrates an exemplary course of the pressure p over time t in the lock chamber 21 (top), in the pressure accumulator 39 (middle) and in the high-pressure line 5 (bottom). The pressure in the unpressurized lock chamber 21 is initially the ambient pressure, which is on the zero line here. In this unprinted phase, the lock chamber 21 can be filled 307 before the start of the printing 309 at the point in time to.

Printing 309, 315 begins at time t0. During the first short time window A=t ₁ -t ₀ the lock chamber 21 is then pressurized 309 to up to 40% of the nominal high pressure po from the pressure discharge of the pressure accumulator 39. The pressure accumulator 39 is then discharged to a minimum at t ₁ and is then via the pressure accumulator valve 43 according to the second embodiment in FIG 2 locked. However, the sluice chamber 21 continues to be slowly pressurized 315 within the second, longer time window B=t ₂ -t ₀ via the throttle 41 from the high-pressure line 5 until the nominal high pressure po is reached at t ₂ . The imprinting 309, 315 of the lock chamber 21 can take 5 to 10 seconds. As soon as the nominal high pressure po is reached in the lock chamber 21 at t ₂ , the refilling 311 can begin and the pressure vessel 39 can be pressurized 313 again at the same time. In the embodiment according to 3 without a pressure accumulator 39, the lock chamber 21 is completely pressurized from the high-pressure line 5 via the throttle 41 over the time window B.

The refill valve 19 is open between t ₂ and t ₃ so that abrasive medium can flow into the pressure container 11 . At time t ₃ the abrasive has flowed completely out of the lock chamber 21 into the pressure vessel 11 and the refilling step 311 is completed. For filling 307, the pressure can be released from the sluice chamber 21 relatively quickly via the pressure relief valve 27 into the outlet 29 until at t ₄ there is low pressure in the sluice chamber 21 again. A new refill cycle can then start, beginning with the filling 307 of the lock chamber 21 . The pressure accumulator 39 is preferably pressurized again as slowly as possible and throttled from t ₂ onwards from the high-pressure line 5 in order to be fully pressurized again at t o for the pressurizing 309 . The lower graph shows the pressure drop in the high-pressure line 5 when the pressure valve 37 opens at t o and the pressure accumulator valve 43 at t ₂ . The amplitude of the pressure drop is reduced in each case via the throttle 41 to a level at which the cutting performance of the cutting jet 9 is not significantly impaired.

In Figures 15a and 15b the refill valve 19 is shown in cross section in more detail in different open positions. Since the refill valve 19 has to be actuated under high pressure at the valve inlet 49 and the valve outlet 51, trouble-free actuation of the refill valve 19 is a technical challenge. The reliable opening and closing of the refill valve 19 is now ensured by four sub-aspects, each of which contributes individually or in any combination of two, three or all four sub-aspects to the refill valve 19 not becoming clogged or blocked by the abrasive.

The refill valve 19, which is preferably designed as a ball valve, has a vertical flow direction D from top to bottom and has a centrally arranged valve body 67 that can be rotated about an axis of rotation R perpendicular to the flow direction D and has spherical outer surfaces. The valve body 67 has a central opening 69 in the Figures 15a and 15b shown opening positions parallel to the flow direction D and perpendicular to the axis of rotation R. The first opening position according to Figure 15a differs from the second open position accordingly Figure 15b in that the valve body 67 is rotated through 180° with respect to the axis of rotation R. The valve body 67 sits in a valve chamber 71 between an upper valve seat 73 and a lower valve seat 75. The upper valve seat 73 forms the valve inlet 49 and the lower valve seat 75 forms the valve outlet 51. The upper valve seat 73 and the lower valve seat 75 are coaxial to one another and to the vertical flow direction D arranged. The valve chamber 71 can be flushed through via the lateral flushing inlet 66 and via the flushing outlet 63 diametrically opposite the flushing inlet 66, preferably when the refill valve 19 is completely pressureless.

According to the first sub-aspect, the refill valve 19 is capable of a first closed position ( 16a ), a first opening position ( Figure 15a ) and a second opening position ( Figure 15b ) to take, whereby in the first closed position ( 16a ) the lock chamber 21 is fluidly separated from the pressure vessel 11 and in the first and the second open position ( Fig. 15a-b ) the lock chamber 21 is fluidly connected to the pressure vessel 11 . Because of the symmetry of the valve body 67, the first open position and the second open position are essentially indistinguishable. The valve body 67 can be rotated as far as desired in one direction about the axis of rotation R, so that a reversal of the direction of rotation is not necessary in principle and the valve body 67 can only be actuated in one direction of rotation, provided the torque required for this does not exceed a certain threshold value. The first closed position off 16a is here at 90 ° between the first open position and the second open position. In this case there is also a second closed position (see Figure 16b ), which is rotated by 180° about the axis of rotation R compared to the first closed position. The opening 69 runs into the in Figures 16a and 16b shown closed positions both perpendicular to the direction of flow D and perpendicular to the axis of rotation R, so that the Valve body 67 seals the valve inlet 49 on the upper valve seat 73 and the valve outlet 51 on the lower valve seat 75. Here the optional flushing inlet 66 and flushing outlet 63 are not shown, but can be provided. Thus, there are always two options for the direction of movement for the valve body 67, to open or close the refill valve 19 either to the first open position/closed position or to the second open position/closed position if a direction of movement currently requires too high a torque. If one direction of movement is clogged or blocked, the valve body 67 can be moved in the other direction of movement and the valve 19 can be brought into the other open position/closed position. The constipation or blockage can be released as a positive side effect of the reversal, so that the previously blocked direction of movement is free again the next time it is operated. The refill valve 19 can also be shaken free by turning it back and forth several times, for example if the valve body 67 is difficult to actuate in both directions of movement.

According to the second sub-aspect, the valve chamber 71 can be pressurized when the valve body 67 is in a closed position. According to Fig. 17a-b For this purpose, the valve chamber 71 has the pressure inlet 53, via which the valve chamber 71 can be pressurized when the valve body 67 is in a closed position. The pressure inlet 53 is arranged here in the yz plane coaxially to a servomotor shaft 86 opposite this. As an alternative to this, the pressure inlet 53 can also lie in the xz plane perpendicular thereto and, if necessary, can be used as a flushing inlet 66 as required. The valve body 67 is rotated about the axis of rotation R via the servo motor shaft 86 . When the initially depressurized system 1 is started or restarted, the valve chamber 71 is initially depressurized. If the pressure vessel 11 and the sluice chamber 21 are then pressurized to about 2,000 bar, the valve body 67 can be pinched by the valve seats 73, 75 because of the high pressure on the inlet and outlet side with the simultaneous low pressure in the valve chamber 71 and only become difficult or impossible to move. By means of the pressure inlet 53, the pressure difference between the valve chamber 71 and the valve inlet 49 or the valve outlet 51 can be largely reduced during start-up, so that the valve body 67 is not pinched by the high pressure. In Figure 17b the upper valve seat 73 according to the fourth sub-aspect is shown adjustable via an adjustment device. The upper valve seat 73 can be positioned in the z-direction via an external thread by means of a rotation about the direction of flow D. The rotation can be carried out manually or motor-driven by levers 88 acting from the outside in engagement surfaces 77 .

According to the third sub-aspect, the valve space, such as in Fig. 15a-b shown flushable. The refill valve has the flushing inlet 66 and the flushing outlet 63, via which the valve chamber 71 can be flushed. The pressure inlet 53 can optionally serve as a flushing inlet 66 . This is particularly advantageous in combination with the second sub-aspect of a pressure inlet 53, since a flushing cycle can be carried out when the valve chamber 71 is pressureless or the system 1 is completely pressureless, and then when the system 1 is put into operation again, the valve chamber 71 can be pressurized again via the pressure inlet 53, so that the valve body 67 is not pinched by the high pressure.

According to the fourth sub-aspect, the refill valve has the upper valve seat 73 on the inlet side and the lower valve seat 75 on the outlet side, at least one of the valve seats 73, 75 being adjustable so that the distance between the valve seats 73, 75 can be adjusted. Thus, the refill valve 19 can be optimally adjusted in order to be tight on the one hand and not to block on the other hand. The distance between the valve seats 73, 75 to one another can be readjusted when the system is started up, in the event of temperature fluctuations, a stubborn blockage caused by abrasives and/or material wear be beneficial. In order not to have to switch off and disassemble the system for this, as in 18a A tool opening 90 can be provided as shown, through which a tool in the form of a lever 88 can reach in order to adjust the at least one adjustable valve seat 73. However, the valve seat 73 is preferably adjusted in a service procedure with the system 1 depressurized. In this example, the upper inlet-side valve seat 73 can be adjusted axially along the flow direction D via an external thread. Levers 88 can be attached from the outside to engagement surfaces 77 (see Figure 18b ) to turn the valve seat 73. The refill valve 19 therefore does not have to be separated from the system 1 or dismantled. The operator can thus immediately intervene manually in order to ensure continuous operation, or switch off and depressurize the system 1 in order to carry out the adjustment of the valve seat 73 as a service procedure. Alternatively or additionally, the readjustment can also be automatically controlled and/or regulated via a motor.

The valve body 67 is preferably rotated about the axis of rotation R in a controlled manner via a servomotor (not shown). The torque that may be measured or the power consumption of the motor can be monitored, so that if a threshold value is exceeded, the direction of rotation can be switched to the other open position or closed position. Alternatively or additionally, torque or power peaks can be recorded over a certain period of time and based on this recording, an error or maintenance case can be signaled. For example, the need for readjustment of the valve seat 73 can be indicated.

Fig. 19a-b show two embodiments of flushable needle valves, which are used for example as one or more of the shut-off valves 15, 27, 33, 37, 47 or elsewhere in the plant 1 can become. The needle valve according to Figure 19a is preferably used where the needle valve does not have to open or close under high pressure, e.g. as a pump shut-off valve 33 in the circuit to support the filling of the sluice chamber 21. The pump shut-off valve 33 has a high-pressure inlet 92 which is arranged coaxially with the high-pressure inlet 92 and is axial positionable needle 94 with respect to a low-pressure outlet 95 can be shut off. At one end facing the high-pressure inlet 92, the needle 94 has a conical closing surface 96 which can be pressed against a valve seat 98 for shutting off. As soon as the high-pressure inlet 92 is shut off, high pressure can be applied to the high-pressure inlet 92 without it escaping via the low-pressure outlet 95 . When there is no high pressure at the high pressure inlet 92 , the pump isolation valve 33 can be opened to allow low pressure flow from the high pressure inlet 92 to the low pressure outlet 95 .

The needle valve according to Fig. 19a-b also has a flushing inlet 100 through which the opened needle valve can be flushed, flushing liquid, ie water or water with cleaning additives, being able to flow out via the low-pressure outlet 95 . Through this flow of flushing liquid, in particular the valve seat 98 and the closing surface 96 can be freed from abrasive residues in order to ensure clean closing with as little material wear as possible. The needle valve can preferably be flushed shortly before the refill valve 19 closes. Figure 19b 12 shows a needle valve with a check valve 102 at the flushing inlet 100. The check valve 102 prevents backflow into the flushing inlet 100 and only allows flushing liquid to flow in the direction of the needle valve. This makes sense when the needle valve is used, for example, as one or more of the shut-off valves 15, 27, 37, 47, since the valve is opened there when high pressure is present at the high-pressure inlet 92 reigns. Without the check valve 102 , this high pressure would at least partially discharge into the scavenging inlet 100 and lead to a backflow into the scavenging inlet 100 . The check valve 102 prevents this and thus enables a clean pressure release via the low-pressure outlet 95. The low-pressure outlet 95 can also be a high-pressure outlet 95 in this case. For example, in the case of the pressure relief valve 27 , the low-pressure outlet 95 is connected to an outlet 29 . In the case of the pressurization valve 37, however, the high-pressure outlet 95 is connected to the pressurization inlet 35 of the lock chamber 21 in order to subject it to high pressure.

The needle valves are preferably operated pneumatically via a pressure plate (not shown). In order to counteract the high pressure acting on the tip of the needle in the form of the conical closing surface 96, air pressure can be applied to the much larger pressure plate so that the needle valve can be closed with a few bar of air pressure and kept tight against a high pressure of 1,500 bar and more.

The numbered designations of the components or directions of movement as "first", "second", "third", etc. are chosen herein purely arbitrarily to distinguish the components or directions of movement from one another and can be chosen arbitrarily differently. There is no rank associated with it.

Reference List

1 -

Water-abrasive suspension cutting system

3 -

high pressure source

5 -

high pressure line

7 -

outlet nozzle

9 -

cutting jet

11 -

pressure vessel

13 -

Water abrasive suspension

15 -

shut-off valve

17 -

throttle

19 -

refill valve

21 -

lock chamber

23 -

filling valve

25 -

refill funnel

27 -

pressure relief valve

29 -

process

31 -

pump

33 -

pump shut-off valve

35 -

printing input

37 -

pressure valve

39 -

accumulator

41 -

throttle

42 -

throttle

43 -

accumulator valve

45 -

funding aid

47 -

Conveyor Aid Shutoff Valve

49 -

valve inlet

51 -

valve outlet

53 -

pressure inlet

55 -

purge source

57 -

first flush valve

59 -

second purge valve or purge outlet valve

61 -

third flush valve

63 -

purge outlet

65 -

process

66 -

flush inlet

67 -

valve body

68 -

sampling point

69 -

breakthrough

70 -

abrasive line

71 -

valve space

72 -

level sensor

73 -

upstream valve seat

74 -

level sensor

75 -

downstream valve seat

76 -

level sensor

77 -

attack surfaces

78 -

pre-charge container

80 -

pump

82 -

overflow

84 -

Auger

85 -

conveyor belt

86 -

servo motor shaft

88 -

lever

90 -

tool opening

92 -

high pressure inlet

94 -

needle

95 -

Low pressure outlet/high pressure outlet

96 -

conical closing surface

98 -

valve seat

100 -

flush inlet

102 -

check valve

301 -

Providing water under high pressure in the high-pressure line

303 -

providing a pressurized abrasive suspension in the pressure vessel

305 -

Cutting a material using a high-pressure jet

307 -

Filling an unpressurized lock chamber with abrasive or a water-abrasive suspension

308 -

Shut off the pump from the lock chamber

309 -

Pressurizing the lock chamber by discharging the pressure accumulator

311 -

Refilling the pressure vessel with abrasive

313 -

Pressure loading of the pressure accumulator

315 -

Pressurizing the sluice chamber via the throttle from the high-pressure line

A -

first time window

B -

second time window

R -

axis of rotation

D -

flow direction

F1 -

level cone

F2 -

level cone

Fmax -

maximum level cone

fmin -

minimum level cone

Claims (16)

1. A water-abrasive suspension cutting facility (1), with

   - a high-pressure source (3) for providing (301) water at a high pressure,

   - a high-pressure conduit (5) which is connected to the high-pressure source (3), and

   - a pressure tank (11) for providing (303) an abrasive agent suspension (13) which is at a high pressure, characterised in that

   the pressure tank (11) is fluid-connected to the high-pressure conduit (5) via a regulatable throttle (17), wherein the throttle (17) is arranged at the entry side of the pressure tank (11) and is configured to regulate the feed flow into the pressure tank (11) from the high-pressure conduit (5) in dependence on at least one control variable.
2. A water-abrasive suspension cutting facility (1) according to claim 1, wherein a shut-off valve (15) is arranged upstream or downstream of the throttle (17).
3. A water-abrasive suspension cutting facility (1) according to claim 2, wherein the shut-off valve (15) is designed to shut off the pressure tank (11) from the high-pressure conduit (5) in dependence on at least one sensor signal.
4. A water-abrasive suspension cutting facility (1) according to one of the preceding claims, wherein the at least one control variable comprises a sensor signal and/or an operating parameter of the high-pressure source (3).
5. A water-abrasive suspension cutting facility (1) according to one of the preceding claims, wherein the at least one control variable comprises an abrasive agent flow out of the pressure tank (11) or a parameter which is characteristic of an abrasive agent flow out of the pressure tank (11).
6. A water-abrasive suspension cutting facility (1) according to one of the preceding claims, with a first filling level sensor (72) for signalising at least one first filling level (F1) of abrasive agent in the pressure tank (11), wherein the at least one control variable comprises a temporal change of the first filling level (F1).
7. A water-abrasive suspension cutting facility (1) according to one of the preceding claims, with a first filling level sensor (72) for the signalisation of at least a first filling level (F1) of abrasive agent in the pressure tank (11) and with a second filling level sensor (74) for the signalisation of at least a second filling level (F2) of abrasive agent in the pressure tank (11), wherein the at least one control variable can comprise a time difference between the first filling level (F1) and the second filling level (F2).
8. A water-abrasive suspension cutting facility (1) according to one of the preceding claims, with an abrasive agent flow sensor (79) which is arranged at the exit side of the pressure tank (11), wherein the at least one control variable comprises an abrasive agent flow which is signalised by the abrasive agent flow sensor (79).
9. A water-abrasive suspension cutting facility (1) according to one of the preceding claims, wherein the at least one control variable comprises a speed and/or a power consumption or electricity consumption of the high-pressure source (3).
10. A method for the water-abrasive suspension cutting with the steps:

    - providing (301) water at a high pressure in a high-pressure conduit (5) by way of a high-pressure source (3),

    - providing (303) an abrasive agent suspension (13) which is at a high pressure in a pressure tank (11), and

    - cutting (305) a material by way of a high-pressure jet (9) which at least partly comprises the abrasive agent suspension, amid the removal of the abrasive agent suspension (13) out of the pressure tank (11),

    characterised in that the method also comprises the step of:

    - regulating a feed flow into the pressure tank (11) out of the high-pressure conduit (5) by way a regulatable throttle (17) which is fluid-connected to the pressure tank (11) at the entry side, in dependence on at least one control variable.
11. A method according to claim 10, wherein the regulating is effected in dependence on a sensor signal and/or an operating parameter of the high-pressure source (3).
12. A method according to claim 11 or 12, wherein the regulating is effected in dependence on an abrasive agent flow out of the pressure tank (11).
13. A method according to one of the claims 10 to 12, wherein the regulating is effected in dependence on a temporal change of a first filling level (F1) of abrasive agent in the pressure tank (11), wherein the first filling level (F1) is signalised by a first filling level sensor (72).
14. A method according to one of the claims 10 to 13, wherein the regulating is effected in dependence on a time difference between a first filling level (F1) of abrasive agent in the pressure tank (11) and a second filling level (F2) of abrasive agent in the pressure tank (11), wherein the first filling level (F1) is signalised by a first filling level sensor (72) and the second filling level (F2) by a second filling level sensor (74).
15. A method according to one of the claims 10 to 14, wherein the regulating is effected in dependence on an abrasive agent flow, wherein the abrasive agent flow is signalised by an abrasive agent flow sensor (79) which is arranged at the exit side of the pressure tank (11).
16. A method according to one of the claims 10 to 15, wherein the regulating is effected in dependence on a speed or power consumption or electricity consumption of the high-pressure source (3).

Images