EP2551450A1 - Device for creating a pressure differential for a fluid or multi-phase material system - Google Patents

Abstract

The apparatus has a rotating main portion (1) which is rotationally symmetrical with respect to rotation axis and coated with diamond-like carbon. A stationary plastic base (2) is located parallel to radially outer surface of main portion. The diffuser side of the base is sucked with main portion through the openings (3,4) formed in main portion and apertures (5,6) formed in base. The surfaces of main portion and base in which openings and apertures are formed, are arranged at predefined distance with respect to one another or in sliding solid contact.

Description

The invention relates to a device for generating a pressure difference for a fluid or a Mehrphasenstoffsystem. It is a use as a compressor or a pump possible to achieve a desired increase or decrease of a pressure. In this case, a negative pressure, up to the vacuum, in a connected container, a corresponding pressure increase in a connected container but also a promotion of a fluid or a multi-phase system can be achieved.

Fluids are liquids or gases, which may also be a mixture thereof. A multiphase system may be a suspension or emulsion in which liquid, solid or viscoelastic components, other liquids, vapors, aerosols or particles are contained in a liquid can.

Conventional devices are often subject to increased wear, which is caused by friction of touching surfaces. If pressure differences are generated with turbomachines in which no or a low friction effect occurs, their efficiency is limited or the production is complex and costly.

In general, such systems or devices are effectively operable only in one direction, so that either an increase in pressure or a pressure reduction in one direction can be achieved with a correspondingly high efficiency.

It is therefore an object of the invention to provide a device that is simple and inexpensive, subject to reduced wear and is flexible.

According to the invention, this object is achieved with a device having the features of claim 1. Advantageous embodiments and further developments of the invention can be realized with features described in the subordinate claims.

The invention may represent a tribological system in which the relative movements of rigid bodies in the region of a narrowing gap lead to a pressure change in the direction of movement before the gap (Konfusorseite) to a pressure increase and in the direction of the gap (diffuser side) by tribological Initiated flows lead to a reduction in pressure. In particular, in a rotational movement of a body, a reduction in the gap distance between the surface of the rotating body, which is to be referred to as a counter body, and the surface of a stationary body arranged by the rotational movement can be exploited. The pressure of the precursor is due to the relative movement and the thereby narrowing gap between the surfaces of the counter-body and of the / the basic body, which are turned towards each other, increased at the Konfusorseite. In the direction of movement of the counter body behind the Konfusorseite the diffuser side is arranged. There, the pressure can be reduced.

In this case, a counter body and at least one base body is a sliding system, between which an intermediate substance, as a fluid or Mehrphasenstoffsystem is present, the pressure of which is to be changed with the device.

The inventive device for generating a pressure difference for a fluid or a Mehrphasenstoffsystem has a rotating about a rotation axis counter body, which is rotationally symmetrical with respect to the axis of rotation, which can also be called rotor. Its radially outwardly facing surface is convexly curved.

In addition, at least one stationary base body is present.

The base body (s) has a surface aligned parallel to the radially outer surface of the counter body. This surface may in one alternative be a planar flat surface.

In a further alternative, it may be concavely curved on the surface facing the radially outer surface of the mating body, wherein the radius of curvature is then greater than the radius of curvature of the mating body.

At least one opening (channel), each with at least one opening, is formed on the base body by the base body.

Through the opening (s) and the one opening can be a fluid or multi-phase system at the diffuser side of the body be sucked in with rotating counter body.

A fluid or multiphase system may also be removed / delivered through the confuser-side orifice (s) and the elevated pressure port.

The surfaces of the mating body and base body are arranged in the region of openings of the aperture (s) at a defined distance from each other or they are in sliding solid contact with each other.

On a base body, only an opening may be present, which represents the mouth of an opening in the direction of the interior of the device. Everything is accommodated in a sealed housing and the opening is led to the outside. Depending on the arrangement or the direction of rotation of the main body of the opening on the diffuser or Konfusorseite then a flow through the opening in the interior of the housing or out of the housing can be generated, which leads to a corresponding pressure difference. In this case, an additional inflow or outflow for the fluid or Mehrphasenstoffsystem on the housing at least then available when an incompressible fluid or Mehrphasenstoffsystem is used. By a pipe connected to you outside of the housing line can there, depending on the increased or reduced pressure of the precursor (fluid or Mehrphasenstoffsystem) can be achieved. At an inflow or outflow, a valve may be present.

However, it is also possible to provide on a base body at least two openings, which are each associated with an opening, wherein in each case at least one opening is arranged on the diffuser side and the at least one other opening on the confuser side. In this case, the flow of a fluid or a multiphase system from one aperture through the openings to the other aperture be achieved, so that an opening can form a suction side and the other opening the pressure side of the device.

With the device according to the invention can be selectively taken influence on the achievable pressure difference and the volume flow to be delivered. By reversing the direction of rotation of the opposing body, it is possible to achieve a reversal of the flow direction and of the pressure gradient that can be generated because of the otherwise symmetrical conditions. Influence can also be taken by the speed and a change in the distance of the mutually facing surfaces of opposing and basic bodies. In this case, the gap can be adjusted so that the tribolgically influenced flow conditions affect these parameters in the desired shape. With a larger gap width, the achievable pressure difference is reduced and the volume flow to be delivered also decreases.

The pressures at the confuser and at the diffuser side as well as the achievable volume flow can be influenced by several parameters. Thus, a proportional dependence on the dynamic viscosity η [Nsm ^-2 ] of the fluid or Mehrphasenstoffsystems to be pumped, the velocity v [ms ^-1 ] of the layer thus formed in the gap between the base and counter body, which in turn is a function of the relative velocity of the sliding partner Basic and opposite body is to be considered. In addition, the pressure difference is inversely proportional to the thickness .DELTA.h of the layer of fluid or Mehrphasenstoffsystems in the gap between the base and the counter body. Pressure difference and volumetric flow are also dependent on the quotient of the active surface segment A _R [m ² ] of the counter body and the sum of the areas of the free cross sections A _D [m ² ] and A _K [m ² ] of the openings on the main body. In this case, the active surface segment A _{R of} the counter body is the product of the optimum distance AB (see Fig. 1 ) and the width of the system, which is characterized by the width of the openings in the body.

This fact is reflected in the following equation: $$\mathrm{Ap}\mathrm{=}\left(\mathrm{\eta }\mathrm{*}\mathrm{v}\mathrm{/}\mathrm{.delta.h}\right)\mathrm{*}\left({\mathrm{A}}_{\mathrm{R}}\mathrm{/}\left({\mathrm{A}}_{\mathrm{D}}\mathrm{+}{\mathrm{A}}_{\mathrm{K}}\right)\right)\mathrm{,}$$

The sliding system formed with the base body and counter body can be arranged or adjusted such that the surfaces touch or there is a gap in which there is no solid-body contact.

In the device according to the invention, a plurality of base bodies can be distributed over the circumference. As a result, the efficiency and at least the flow rate can be increased. Variations in the pressure generated and volume flow can largely be reduced as a result. Basic body can be arranged distributed to each other over the circumference of the counter body with in each case equal angular distances.

On a base body, at least one opening of an opening and at a distance from the latter in the direction of rotation at least one further opening of an opening can be arranged on the diffuser side.

In this case, a plurality of apertures, which are arranged on the diffuser side of the base bodies, and / or a plurality of apertures, which are arranged on the Konfusorseite of basic bodies, be connected to each other via a loop.

In the invention, it is possible to form a counter-body with an at least twice graduated outer surface, thereby different outer diameters are present in the individual stages. A counter-body can be integrally formed with different outer diameters or by arranging a plurality of individual counter-bodies in series with a common axis of rotation.

A mating body can also be in the form of a cone or truncated cone be educated.

In these two cases, openings of apertures in different planes perpendicular to the axis of rotation of the counter body may be arranged on one or more base bodies. As a result, openings with different distances to the rotation axis are effective. As a result, different speeds occur at the correspondingly arranged openings between the sliding partners of the base and counter body, depending on the distance, which in turn can lead to different pressure differences and volume flows.

The base body (s) may likewise be formed with surfaces arranged correspondingly to the stepped outer diameters of the counter body. In another design possibility, a plurality of base bodies may be arranged in the individual outer diameter steps of the counter body corresponding planes. In this case, basic bodies can also be designed in a form complementary to a cone.

This makes it possible to connect apertures with openings arranged in different planes, so that a cascaded pressure difference generation can be achieved. Thus, the pressure may be increased or decreased from a pressure level to a higher or lower pressure level in stages, depending on the direction in which the apparatus is operated.

In general, influence on the achievable pressure difference or the delivered volume flow can also be taken by a specific change in the distance of the radially outer surface of the counter body to the surface of the base body (s) facing the surface of the counter body, such as this has already been expressed with the possible change in the gap between the base and counter bodies is.

Pressure difference and flow are also dependent on the nature, in particular of the topography, the surface of the counter body. In accordance with the respective fluid or multiphase system to be delivered, this surface should be designed so that the near-surface layer on the counter body, the strength of which decisively influences the pressure build-up or release, is optimally designed with respect to the effectiveness of the device.

In the invention, openings may have a rectangular free cross section and / or a plurality of openings may form a series arrangement, wherein an orientation of the openings or a row arrangement should be maintained perpendicular to the rotational movement of the counter body. The rectangular shape can be chosen so that a large part of the surfaces of the base and counter-bodies in the diffuser and / or Confusorbereich can be used. Openings should therefore be guided almost completely over the entire width parallel to the axis of rotation, except for small areas in the direction of the outer end faces of the main body and in the direction of the movement vector have a limited width compared to the direction perpendicular thereto.

If openings are present in a row arrangement, they can have both a rectangular shape and another geometric shape, for example a circular shape. In this case too, however, the comments on the formation of rectangular openings should be taken into account mutatis mutandis.

In the invention, advantageously, the radially outer surface of the counter body may be provided with a coating of diamond-like carbon and then base body made of fiber reinforced, preferably carbon fiber reinforced plastic at least partially in the region facing the counter body exist.

However, such a material pairing can also be provided with radially outer surfaces of base bodies, which are provided on facing surfaces of base bodies with a coating of diamond-like carbon, and a counter body which, at least in the region facing the base bodies, consists of fiber-reinforced, preferably carbon-fiber reinforced plastic. be achieved. The use of such fiber-reinforced plastics in combination with a coating of diamond-like carbon is particularly advantageous when it comes to a solid contact on the friction pairing of the base and counter body during operation.

This pairing of materials is particularly suitable when the counter and base body are arranged to each other in the device so that it comes to solid state contact, since they achieve a very favorable Reibverschleißarmes behavior and act small frictional forces.

In a device according to the invention, the distance between the radially outer surface of the counter body and the surface of the / the base body adjusted so and the arrangement of bodies are chosen so that there is solid contact in the direction of rotation of the counter body in an alternative in front of at least one opening on the Konfusorseite , In this case, there should be no other opening (s) on the diffuser side.

The distance and the arrangement can also be selected in a further alternative, that in the direction of rotation of the counter body after at least one opening on the diffuser side solid contact, in which case no opening (s) should be present on the Konfusorseite (n).

In a third alternative, certainly the most used should be, the distance and the arrangement can be chosen so that there is solid contact between the openings on the Konfusorseite and on the diffuser side and base and counter body form a friction pairing.

In an embodiment in which solid-state contact occurs or can occur, the material pairing diamond-like carbon and carbon fiber reinforced plastic is particularly favorable.

In an advantageous embodiment, the counter body and base body can be moved relative to each other. This movement can be one-dimensional, but preferably also two-dimensional. By a relative movement in an axis which is directed radially outward starting from the axis of rotation, the distance of the mutually facing surfaces of counter and base body and thus the gap between the two can be changed, which in turn the achievable pressure difference and the flow can be influenced.

However, a one-dimensional movement can also take place perpendicular to this axial direction, which can be achieved in the simplest case by a translatory movement of a base body. In this case, not only the distance of counter and base bodies to each other can be changed. It is also possible a change in the distance between the position of the smallest gap between the mating body and the base body and at least one opening on the base body, through which a fluid or multi-phase system is sucked or conveyed with increased pressure. This also influences the achievable pressure difference and volume flow, since the pressure ratios utilized in the invention on the confuser side and the diffuser side are also influenced by this distance.

With the invention, the possibility opens up a continuous operation even in the absence or low solid state contact perform. As a result, the wear due to friction can be reduced. It can be a nearly constant pressure difference and a delivered volume flow, which are free of fluctuations can be achieved.

There are only a few mechanically moving parts available, valves or similar acting elements can be completely dispensed with. The production and installation can be done with little effort, so that the costs are correspondingly low.

The invention will be explained in more detail by way of example in the following.

• Figur 1 in schematischer Form die zwischen einem Gegenkörper und einem Grundkörper in unterschiedlichen Bereichen und Abständen erreichbaren Drücke bei konstanter Winkelgeschwindigkeit und konstantem Abstand der aufeinander zu gewandten Oberflächen eines Grund- und eines Gegenkörpers;
• Figur 2 in schematischer Form ein erstes Beispiel einer erfindungsgemäßen Vorrichtung;
• Figur 3 in schematischer Form ein weiteres Beispiel einer erfindungsgemäßen Vorrichtung und
• Figur 4 in schematischer Form ein drittes Beispiel einer erfindungsgemäßen Vorrichtung.

Showing:

• FIG. 1 in schematic form, the pressures achievable between a counter-body and a base body in different areas and distances at a constant angular velocity and constant distance of the mutually facing surfaces of a base and a counter body;
• FIG. 2 in schematic form a first example of a device according to the invention;
• FIG. 3 in schematic form, another example of a device according to the invention and
• FIG. 4 in schematic form, a third example of a device according to the invention.

With FIG. 1 The physical-technical basics for understanding the operation of the device should be clarified.

The FIG. 1 shows a base body 2, which is designed as a stator and a about an axis of rotation with the angular velocity ω rotating counter body (rotor) 1. In the area of the contact point or the smallest gap between the base and the counter body, the normal force F _N acts. This point is characterized in that the pressure curve in the fluid or Mehrphasenstoffsystem, which is located between the base and the counter body, has a Nullduchgang.

In the direction of movement before the contact point or the smallest gap between the base and the counter body is built in the fluid or Mehrphasenstoffsystem through the narrowing gap on an overpressure. The area of this pressure buildup is technically described by the term confuser.

In contrast, builds in the direction of movement after the contact point or the smallest gap between the base and the counter body in the fluid or the Mehrphasenstoffsystem a negative pressure. This diffuser region of the device is characterized by an opening gap.

In the circumferential direction, a pressure maximum (point A on the confuser side) or a pressure minimum (point B on the diffuser side) in the fluid or in the multiphase system is formed in each case at a characteristic distance from the contact point or the smallest gap between the base body 2 and the counterbody 1 out. The distance in the circumferential direction is the distance A-B between the two extreme pressures marked. In the device described here, this distance A-B designates the optimum distance between the openings on the diffuser side and the confuser side.

These physical conditions are in the FIG. 1 shown by measurement results, as well as by calculation results in the form of corresponding diagrams. These graphs show the pressure curve in the fluid or in the multiphase system as a function of the distance from the force introduction x, ie the contact point or the smallest Gap between the main body 2 and the counter body. 1

In FIG. 2 a first simple example of a device according to the invention is shown. This device is used as a pump as shown.

In this case, a counter body 1 is present, which is rotatable about an axis of rotation. The counter body 1 has the shape of a cylinder or a cylindrical disk, its radially outer surface is aligned parallel to the axis of rotation. In this example, a base body 2 in the form of a plate or a cuboid is present, whose planar planar surface, which faces the counter body 1, also aligned parallel to the axis of rotation.

Through the main body 2, two channel-shaped openings 5 and 6 are formed, which open at the surface facing the Gegenkörper1 in each case an opening 3 and 4. At the openings 5 and 6 connecting pieces 7 and 8 are connected. When rotating counter body 1, as indicated by the arrow, so a suction and pressure effect according to the arrows on the connecting pieces 7 and 8 can be achieved. Thus, via the connecting piece 8, the opening 6 and the opening 4, a suction effect and the connection piece 8 generates a negative pressure. So sucked fluid or a multi-phase system then passes by means of the force on the Konfusorseite through the opening 3, the opening 5 and the connecting piece 7 to the outside, out of the device with increased pressure.

The counter body 1 is made of hardened steel, its radially outer surface is ground and provided with a thin closed coating of diamond-like carbon. It has an outer diameter of 60 mm and can be rotated at a speed of 3000 min ^-1 . The main body 2 is made of carbon fiber reinforced epoxy resin and is pressed with a normal force F _N of 10 N to the counter body 1.

The openings 3 and 4 have a rectangular cross-section, wherein the longer edges of the rectangle are aligned parallel to the axis of rotation. They have the dimensions of 3 mm * 30 mm and are centered with respect to the width of the counter body 1 and the base body 2.

This device can also be operated with opposite direction of rotation without further notice. In this case, the conveying direction and the pressures change opposite and from the connecting piece 8, the fluid or multi-phase system is pumped out and on the side of the connecting piece 7 can then be sucked by the negative pressure acting there, a fluid or multi-phase system or pumped out of a container.

The FIG. 3 shows an example of a device with a counter body 1, which is again made in the form of a cylinder with a diameter of 120 mm and a width of 50 mm made of stainless steel and rotated about a rotation axis. About its circumference in this example, four main body 2 are arranged distributed to each other at equal angular intervals, which are also formed as plate-shaped elements. The mutually facing surfaces of the mating body 1 and 2 basic bodies have a distance of 0.4% of the outer diameter of the counter body 1, so that no solid contact can occur through the correspondingly narrow gap.

The main body 2 are formed in this example of cast thermoset polyurethane. The openings 3 and 4 have on the four basic bodies 2 each free cross-sectional areas with the dimensions of 3 mm * 40 mm. They are again aligned parallel to the axis of rotation. The openings 3 and 4 open again in openings 5 and 6, which in turn open into connecting pieces 7 and 8.

The conveying direction and the pressure conditions at the individual connecting pieces 7 and 8 can be easily with the attached arrows be recognized at the marked direction of rotation.

The openings 3 are arranged on the confuser side and the openings 4 on the diffuser side. In an opposite direction of rotation of the counter body 1, the pressure and flow conditions change opposite to the representation. The statements to the in FIG. 2 example shown apply mutatis mutandis.

In FIG. 4 a third example of a device according to the invention is shown. Here again, a counter body 1 rotating around a rotation axis is present, distributed over the circumference of which several base bodies 2 are again arranged. This example is suitable for conveying a suspension / emulsion of water with mineral oil. The main body 2 are made of epoxy resin. Your the radially outer surface of the counter body 1 facing surfaces are concavely curved and have the shape of a cylinder calotte. The radius of curvature is greater than the radius of curvature of the counter body 1 on its surface.

In addition, all openings 5 and all apertures 6 are each connected to a ring line 9 and 12. The ring line 12 has an inlet connection 11 and the ring line 9 has an outlet connection 10. Accordingly, a fluid is sucked through all the openings 4 on the diffuser side through the ring line 12 and the openings 6 and conveyed through the openings 3 in the openings 5 and the ring line 9 with increased pressure.

In this example, the device is formed with an integrated electric motor, wherein electromagnets 13 are attached directly to the counter body and the electric coils, not shown, are arranged on housing elements.

Claims (14)

Apparatus for generating a pressure difference for a fluid or a Mehrphasenstoffsystem, wherein a rotating about a rotation axis counter body (1) which is rotationally symmetrical with respect to the axis of rotation and has a convex curved surface and at least one stationary base body (2) are present; in which
the base body (2) has / have a surface aligned parallel to the radially outer surface of the counter body (1), which forms a planar planar surface or a concavely curved surface facing the radially outer surface of the counter body (1), the radius of curvature then greater than the radius of curvature of the counter body (1); and
on the base body (2) at least one opening (5, 6), each having at least one opening (3, 4) through the base body (2) is formed, wherein
through the opening (s) (3) and the opening (5) a fluid or multi-phase system is sucked on the diffuser side of the base body (2) with rotating counter body (1)
and or
a fluid or a Mehrphasenstoffsystem by on the Konfusorseite arranged (s) opening (s) (4) and the opening (6) with increased pressure is discharged and
the surfaces of counter-body (1) and base body (2) in the region of openings (3, 4) of the aperture (s) (5, 6) are arranged at a defined distance from each other or in sliding solid contact with each other. Apparatus according to claim 1, characterized in that a plurality of base body (2) are arranged distributed over the circumference. Apparatus according to claim 1 or 2, characterized in that on a base body (2) on the diffuser side at least one opening (3) of an opening (5) and at a distance to this in the direction of rotation at least one further opening (4) of an opening (6 ) are arranged. Device according to one of the preceding claims,
characterized in that a plurality of apertures (5) which are arranged on the diffuser side of base bodies (2), and / or a plurality of apertures (6) which are arranged on the Konfusorseite of basic bodies (2) via a ring line (9, 12 ) are interconnected. Device according to one of the preceding claims,
characterized in that a counter body (1) is formed with an at least twice stepped outer surface, and thereby different outer diameters are present in the individual stages, or
the counter body (1) in the form of a cone or truncated cone is formed and on one or more base body (s) (2) openings (3, 4) of openings (5, 6) in different planes perpendicular to the axis of rotation of the counter body (1) are arranged. Apparatus according to claim 5, characterized in that the / the base body (2) is also formed with according to the stepped outer diameters of the counter body (1) arranged surfaces or
Base body (2) in the individual outer diameter stages of the counter body (1) corresponding levels are arranged or
Base body (2) are formed in a complementary shape to a cone shape. Apparatus according to claim 5 or 6, characterized in that openings (5, 6) arranged in different levels openings (3, 4) are interconnected, so that a cascaded pressure difference generation can be achieved. Device according to one of the preceding claims,
characterized in that the distance of the radially outer surface of the counter body (1) to the surface of the / the base body (s) (2) facing the surface of the counter body (1) is / are variable. Device according to one of the preceding claims,
characterized in that the direction of rotation and / or the rotational speed of the counter body (1) is variable. Device according to one of the preceding claims,
characterized in that openings (3, 4) have a rectangular free cross-section and / or a plurality of openings (3, 4) form a series arrangement, wherein an orientation of the openings (3, 4) or a series arrangement is maintained parallel and perpendicular to the rotational movement of the counter body (1). Device according to one of the preceding claims, characterized in that the radially outer surface of the counter body (1) is provided with a coating of diamond-like carbon and base body (2) made of fiber-reinforced plastic or
the surfaces of base bodies (2) facing the radially outer surface of the counter body (1) are provided with a coating of diamond-like carbon and the counter body consists of fiber-reinforced plastic at least in the area facing the base bodies (2). Apparatus according to claim 11, characterized in that the base body (2) made of carbon fiber reinforced plastic or the counter body, at least in the region which faces the base bodies (2), consists of carbon fiber reinforced plastic. Device according to one of the preceding claims, characterized in that the distance between the radially outer surface of the counter body (1) and the surface of the / the base body (2) adjusted and the arrangement of the counter body (1) and base body (s) (2 ) is selected so that in the direction of rotation of the counter body (1) in an alternative - Before at least one opening (4) on the Konfusorseite or
in another alternative - After at least one opening (3) on the diffuser side or
in a third alternative - There is solid contact between at least one opening (3) and an opening (4). Device according to one of the preceding claims, characterized in that counter-body (1) and base body (2) are at least one, preferably two-dimensionally movable relative to each other.

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