The invention relates to a nozzle head for the discharge of a suspension consisting of fluid and solid particles with at least one nozzle comprising at least one exit opening for the exit of the suspension.
Such nozzles heads are applied for example in facilities for water-jet cutting, for drilling by way of water jet, or in another manner for surface material removal.
With these methods, the material to be machined (processed) is machined by way of a high-pressure water jet amid the addition of abrasive agent. The advantage of this type of machining is the fact that almost all materials can be machined and that the material to be cut is thereby hardly heated.
It is known from the state of the art, to use a water-abrasive jet, to which a cutting agent, a so-called abrasive agent (e.g. garnet sand, glass, slag, olivines, corundum, or the like) is added, for increasing the cutting or drilling performance or also the machining quality, particularly in the case of hard materials. A suspension of water and abrasive agent is formed for this, in the case of water-abrasive suspension cutting, and this suspension is discharged from a nozzle at a high pressure.
A nozzle head for discharging a suspension comprising a fluid as well as an abrasive agent is known for example from EP 1 820 604 B1. The nozzle head comprises at least one nozzle arranged in a stationary manner, with an exit opening, through which opening the fluid is discharged into the atmosphere. A flow guidance element is arranged upstream of the at least one nozzle, so that this is effected in an as defined as possible manner, thus in order to achieve a desired cutting or material removal result. This flow guidance element is arranged upstream of the nozzle and its exit opening, in the flow path of the fluid led to the nozzle, so that the fluid must firstly pass the flow guidance element before it reaches the nozzle and the exit opening. The flow guidance element is designed and arranged in a manner such that it brings the fluid to be discharged into rotation about the longitudinal axis of the flow path, downstream of the nozzle.
This rotation of the fluid on the one hand leads to a widening of the jet of the fluid after the exit from the nozzle, so that the fluid exits the nozzle in a cone-like manner and a diameter of the fluid flow at a distance to the exit opening downstream of the nozzle and which is larger than the diameter of the exit opening is achieved. On the other hand, the material removal performance is improved by way of the rotating fluid flow exiting from the nozzle.
Against this background, it is an object of the present invention, to provide a nozzle head for discharging a suspension of a fluid and of an abrasive agent, by way of which nozzle head the effects described above are improved to an even greater extent.
According to the invention, thus a nozzle head for the discharge of a suspension consisting of fluid and abrasive agent and with at least one nozzle comprising at least one exit opening for the exit of the fluid or liquid is provided, wherein the nozzle head is preferably configured for movement along a feed axis. The nozzle head moreover comprises at least one first drive device, by way of which the nozzle head is rotatable about a first axis which preferably runs parallel to the feed axis. An increased material removal and the machining of a larger surface can be realized due to the fact that the nozzle head itself is brought into rotation about an axis, in particular parallel to the feed axis or in the feed axis.
Not only water, but also any other suitable fluid can be used as a fluid to be discharged. Thus, the fluid with regard to its viscosity can be adapted to the ambient pressure, in particular when using water. Suitable materials such as e.g. garnet sand, glass, slag, olivines, corundum, or the like, can be used as abrasive agent.
The first axis preferably runs parallel to the longitudinal axis of the nozzle head, wherein the longitudinal axis is that axis, in whose direction the flow through the nozzle head is effected. This longitudinal axis is preferably the middle axis of the nozzle head and further preferably corresponds to the feed axis, along which the nozzle head is fed which is to say advanced, for example when forming a bore (drill hole).
Furthermore, at least one flow guidance element can be arranged preferably upstream of the at least one nozzle, in a manner such that the fluid to be discharged is brought into rotation upstream of the nozzle. As already described, a cone-like widening of the jet can be achieved by way of this, and this jet permits a removal of material in a particularly effective manner. The abrasive agent exiting out of the nozzle in the suspension in particular moves on a circular path.
In particular, a spiral or worm-like flow path can be applied as a flow guidance element. Thereby, the screw (worm) defining the flow path in particular can also be designed in a multi-flight manner, for example with three flights. A spiral or screw structure can be designed as an insert or for example as a spiral-shaped path on the inner periphery of a flow channel or on the outer periphery of a middle wall of an annular flow channel.
According to a preferred embodiment, the first axis coincides with the longitudinal or feed axis, so that the nozzle head executes a concentric rotation about its longitudinal axis on machining the material, e.g. on cutting through a metal or on carrying out a drilling.
Alternatively, the first axis can also be arranged distanced to the longitudinal axis or feed axis. An increase of the machining cross section can be achieved by way of this. The nozzle head can thereby either execute a concentric circular movement, but also an eccentric movement. Thus, for example, the longitudinal axis of the nozzle head with the nozzle head can rotate on a circular path about the first axis. Thereby, the feed is then preferably effected along a feed axis extending in the direction of the first axis. If the first axis lies distanced to the feed axis, in particular distanced to it in a normal or parallel manner, then the nozzle head rotates about an axis which is not coincident with the feed axis, i.e. about its longitudinal axis which is offset to the feed axis.
The first axis preferably runs parallel to the longitudinal axis and/or to the feed (advance) axis of the nozzle head. The axes can however also run angled to one another, in particular for example if the nozzle head is arranged angled to the feed (advance) direction, i.e. the longitudinal axis of the nozzle head extends in a manner angled to the feed axis. In this case, the first rotation axis for example can be arranged parallel to the longitudinal axis of the nozzle head or parallel to the feed axis.
According to a further embodiment, the nozzle head comprises a second drive device, by way of which the nozzle head is additionally rotatable about a second axis distanced to the first axis. If the machining is carried out by way of a rotation about the first and the second axis, then not only can an improvement of the machining performance be achieved, but also an increase of the machining cross section. Thus, for example, the first axis can be arranged such that the nozzle head rotates about its longitudinal axis which is distanced to the feed axis in the radial direction. The second axis then for example can run along the feed axis, so that the longitudinal axis and accordingly the first axis of the nozzle head carries out a movement on a circular path about the second axis.
The nozzle head moreover at least in a section which comprises the at least one exit opening can be inclined to the feed axis by an angle α. The machining cross section about the feed axis can also be increased by way of this, wherein the machining geometry can also be simultaneously changed. The material removal performance can alternatively also be increased by way of inclining the exit opening.
According to a preferred embodiment, the nozzle head comprises a nozzle, in particular a centrally arranged nozzle.
The nozzle head however can also be provided with a multitude of exit openings, of which preferably at least some are arranged such that they release jets which are angled to one another. This configuration of the nozzle head moreover improves the machining performance and, depending on the arrangement of the exit openings, permits the realization of special cutting and machining geometries. Thus, the several exit openings can be arranged or inclined to one another, such that the jets which are produced by them, or their middle axes are directed to one another. I.e. the middle axes of the several jets preferably meet at one point which is to say a focus. Alternatively, the middle axes of the several jets can be directed to one another, without intersecting. This means that the middle axes of the jets in an incident/impinging plane of the jets define a smaller area than in the region of the exit plane. The material removal performance can be increased by way of this. Alternatively, the several exit openings can be arranged such that their jets or their middle axes diverge from one another, so that a greater machining area or surface is covered.
According to a further preferred embodiment, the first and/or the second drive device comprises a motor. With such a motor, it can be the case for example of an electrical motor, but also of a hydraulic or pneumatic motor. This design permits a drive which is independent of the suspension flow. In the case that two drive devices are provided, these can each comprise separate motors of this type, so that these can be driven independently of one another, in particular such that the rotations can be controlled independently of one another Alternatively, such a motor can also be provided for two drive devices, wherein the drive devices e.g. comprise gears which are connected to the common drive motor.
A hydraulic motor can also be driven itself by the suspension flow or a fluid flow which is branched out of the suspension.
In particular, the first and/or the second drive device for this can comprise a turbine driven by the fluid flow, or another drive driven by the fluid flow. This design has the advantage that one can make do without an additional drive, such as e.g. an electrical drive, and in particular no additional separate energy supply from the outside is necessary. Thereby, each drive device can comprise a turbine, or a turbine can be provided for the drive of both drive devices. Such a turbine for example can comprise one or more blade wheels, through which blade wheel or blade wheels the fluid flow flows and which is/are brought into rotation. The rotation can then be transmitted onto the drive for rotating the nozzle head, for example via a suitable gear. I.e. the drive in this case is connected to at least one blade wheel. Another suitable drive could be realized by way of displacement elements such as moving pistons in the form of a hydraulic motor.
In particular, it is advantageous if at least one channel is provided in the nozzle head, via which channel fluid can be branched off out of the suspension essentially without any solid particles. This is possible for example if the suspension is brought into rotation by a flow guidance element, as described above. When the suspension rotates, this leads to the particles or the abrasive agent being moved outwards on account of the arising centrifugal forces, whereas the fluid, in particular water, collects in a middle region. If the mentioned channel then leads into the middle region, then here fluid or liquid can be branched off out of the suspension flow, essentially without any abrasive agent. This can be effected in a branching chamber which is connected downstream of the flow guidance element. The channel, via which the fluid can be branched out of the suspension, is further preferably connected to the turbine described above, so that this can be driven by the suspension flow with pure fluid essentially without any abrasive agent. Thus, one prevents abrasive agent of the suspension from being able to damage the turbines. A drive which can forgo an additional separate energy feed can simultaneously be created.
The nozzle head is particularly preferably arranged on a device for water-jet cutting or water-jet drilling, in particular water-abrasive suspension cutting. Such a device for water-jet cutting or water-abrasive suspension cutting with a nozzle head, as has been described beforehand, is likewise the subject-matter of the invention. Such a device as essential constituents moreover comprises a high-pressure pump which brings a fluid, in particular water to an adequately high pressure. The fluid which is under pressure is subsequently led for example through an abrasive agent container, in which it is mixed with the abrasive agent for forming the suspension. It is then led further to the described nozzle head.
The invention is hereinafter described by way of example and by way of the attached figures. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
In the drawings:
Referring to the drawings,
The flow guidance element 12 has the effect that the fluid/suspension which, coming from the connection 4 flows through the passage 10 in the flow direction, must flow spirally through the channel defined by the screw, when it flows through the flow guidance element 12, so that additionally to its movement in the direction of the longitudinal axis X, it undergoes a rotational movement about the longitudinal axis X. The flow retains this rotatory speed component on exit of the fluid out of the flow guidance element 12 towards the nozzle 8, and apart from its axial movement in the direction of the longitudinal axis X simultaneously executes a rotational movement about this axis. The fluid then flows in this spiral movement into the run-in funnel 14 of the nozzle 8. The run-in funnel 14 narrows towards a channel 16 which extends in the inside of the nozzle 8 in the direction of the longitudinal axis X. The channel 16 defines the smallest cross section of the nozzle 8 normally to the longitudinal axis X.
In this example, the channel 16 widens further downstream into a run-out funnel 18. The run-out funnel 18 thus connects to the actual exit opening 20 at the downstream end of the channel 16. A run-out funnel 18 does not need to be provided in each case.
On entry of the fluid into the run-in funnel 14, the fluid flow is accelerated towards the channel 16 on account of the reducing cross section. The rotation effect of the flow is retained on entry of the flow into the run-in funnel 4 and into the channel 16, so that a conical fluid jet 22 widening in the flow direction along the longitudinal axis X is formed on exit of the flow out of the exit opening 20 through the run-out funnel 18.
The abrasive agent in the fluid is pressed outwards on account of the centrifugal force due to the rotation of the flow in the screw of the flow guidance element 12 and further downstream, due to the fact that the abrasive agent has a greater mass than the fluid or the carrier fluid, in which it is located. This effect is retained within the run-in swirl which forms in the run-in funnel 14 and within the channel 16 of the nozzle 8, so that the abrasive gent, after the exit out of the nozzle through the run-out funnel 18, in the liquid jet 22 forms a hollow cone 24 and the abrasive agent is displaced to the outer periphery of the conical fluid jet 22. The abrasive agent in the fluid jet 22 thus in cross section normal to the longitudinal axis X forms an annulus area. The annulus area or surface is also essentially retained on impinging an object. The rotationally energy in the fluid jet 22 still acts on impinging the object, by which means the material-removal energy of the abrasive agent is increased on material removal, so that an improved material removal performance can be achieved.
Thus different fluids are discharged from the second nozzles 9 and the first nozzles 7, specifically a suspension out of the first nozzles 7 and essentially only carrier fluid, preferably water, out of the second nozzles 9, whereas however only one suspension needs to be fed through the connection conduit 4 to the nozzle head 1. A separation into a suspension with a higher concentration of abrasive agent and only fluid for flushing is effected in the nozzle head 1 itself, by which means additional feed conduits for the feed of rinsing fluid become superfluous.
The flow guidance element 12 in the form of a screw and which here is likewise arranged in the central passage 10 and mentioned above defines the spiral-shaped flow channel 11 which has the effect that the flow is brought into rotation in the way and manner which has already been described in the context of
Concerning the previously described embodiments, it is to be understood that individual features here can be combined with one another also in another manner. Thus, all drive devices 17′, 17″ about the axes A1 and/or A2 are designed for example as electrical drives or as water drives, e.g. with turbines, wherein such water drives are preferably supplied with fluid via the connection conduits 5 described above by way of
The essential concept of the invention lies in bringing the nozzle head into rotation about an axis by way of a separate drive, wherein the suspension, as explained by way of
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.
This application is a United States National Phase Application of International Application PCT/EP2014/053259 filed Feb. 19, 2014, the entire contents of which are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2014/053259 | 2/19/2014 | WO | 00 |