DE102007045473A1 - Measuring tube for performing magnetically inductive flow measurement of e.g. liquid medium, has flow-parallel grooves provided in side that is turned towards measuring medium, where grooves are formed in trapezoidal form in cross-section - Google Patents

Abstract

The tube (1) has flow-parallel grooves (3) provided in a side that is turned towards a measuring medium e.g. liquid medium, where the tube is lined with a tubular liner (5) consisting of polymer for guiding the measuring medium. The flow-parallel grooves are formed in trapezoidal form in the cross-section, where the breadth of flow-orthogonal grooves is small in comparison to the breadth of the flow-parallel grooves and/or the depth of the flow-orthogonal grooves is small in comparison to the depth of the flow-parallel grooves. An independent claim is also included for a device for determining and/or monitoring the flow of a measuring medium by a measuring tube.

Description

The The present invention relates to a device for determining and / or monitoring the Flow of a measuring medium through a measuring tube. With the measuring medium it is a flowable medium, in particular to a liquid, a vapor or gaseous Medium.

A technically qualified person is familiar with many different types of flowmeters. These include, for example, flowmeters that measure the volume flow of the measuring medium, or those that measure the mass flow of the medium to be measured. Some flowmeters can be used to determine other parameters besides the flow, such as: B. Substance properties of the medium to be measured. The principles that underlie the most common flowmeters are in the literature, especially the Flow Handbook of Endress + Hauser Flowtec AG, 4th edition of 2003, on pages 55 to 195 described in detail.

On Some systems show the flow of a measuring medium through a measuring tube to determine or monitor will be closer in the following received, without limiting the invention to these variants shall be.

Electromagnetic Flow meters use for volumetric Flow measurement the principle of electrodynamic induction out. Perpendicular to a magnetic field moving charge carriers of Medium induce in substantially perpendicular to the flow direction of the medium and perpendicular to the direction of the magnetic field arranged measuring electrodes a measuring voltage. The measuring voltage induced in the measuring electrodes is proportional to that over the cross section of the measuring tube averaged flow velocity of the medium, ie proportional to the volume flow. Is the density of the medium known, can the mass flow in the pipeline or in the Determine measuring tube. The measuring voltage is usually over a pair of measuring electrodes tapped with respect to the coordinate along the measuring tube axis in the region of maximum magnetic field strength is arranged and therefore where to expect the maximum measuring voltage is. The measuring electrodes are usually galvanic with coupled to the medium. However, they are also magnetic-inductive flowmeters become known with capacitive coupling measuring electrodes.

The Measuring tube in the magnetic inductive flow measurement is either of an electrically insulating material or so called carrier tube is made of an electrically conductive material, such as As stainless steel, and is made with an electrically insulating Lining provided, which comes into contact with the measuring medium. This lining has become known as a liner. The measuring tube exists thus from carrier tube and liner. The liner is usually from a thermoplastic, a thermosetting or an elastomeric Plastic. However, they are also magnetic-inductive flowmeters become known with a ceramic lining.

The Reproducibility of the measurements and thus the measurement accuracy can deteriorates due to short-term fluctuations in volume flow become. Such fluctuations in the flow can on Pressure changes and a resulting vortex formation in the area of the inlet or the outlet be.

Such Flow fluctuations are z. B. by curvatures in Piping system before or after the meter or by changes in the Cross-section in size and / or shape of the tubes before or caused by the meter. Therefore, Endress + Hauser gives its customers a length of the inlet section of at least 5 · DN of the measuring tube and a length the outlet section 2 · DN of the measuring tube with magnetic inductive Flowmeters recommended. There are both In and out of pipes with the approximate same cross-section as the measuring tube. DN, English nominal diameter, stands for the nominal diameter of the pipe. If the length the inlet section so not at least five times or the length of the outlet is not at least twice the inner diameter of the tube is, so is partly significant deviations to be expected.

A Another source of disturbance is deviations of the surface quality in the piping system, especially soiling and deposits. The inlet and outlet sections should therefore also have the same surface finish as the measuring tube itself, at best from the same material how the measuring tube is made. With stubborn dirt or deposits, however, the surface properties both change the inlets and outlets, as well as the measuring tube itself. One special form of deposit makes infestation of piping system or even the measuring system by biological organisms, so-called Biofouling.

Magnetically inductive flowmeters are basically low maintenance. In addition to the contamination of the pipelines, a measurement error caused by non-conductive deposits, eg. As fats in milk production or just fouling of animals or algae, on the measuring electrodes. This increases the cleaning and maintenance costs of a such measuring system.

As with the magnetic inductive flowmeters, so are also used on gauges that are based on ultrasound working, long inlets prescribed for a uniform, To ensure approximately untwisted flow. This can lead to problems, especially when installing the Measuring instruments in already existing systems. Especially at large diameters, magnetic inductive or flow measurement On the basis of ultrasound, it can cause difficulties come to be unable to place the gauges that prescribed entry / exit route are complied with. Also when planning new plants, long infeed / outfeed routes lead at significantly increased costs. Furthermore you can Deposits and contamination in the piping system lead to an impairment of the measurement. For all flowmeters alike prevails the problem of biofouling.

Ultrasonic flowmeters are widely used in process and automation technology. They allow in a simple way, the volume flow in one Determine pipeline without contact.

The known ultrasonic flowmeters either work after the Doppler or after the transit time difference principle.

At the Runtime difference principle, the different maturities of ultrasonic pulses relative to the flow direction of Liquid evaluated. For this purpose, ultrasonic pulses both in and against the flow sent. Out the transit time difference allows the flow rate and thus with a known diameter of the pipe section of the Determine volume flow.

At the Doppler principle will be ultrasonic waves with a specific frequency coupled into the liquid and that of the liquid Evaluated reflected ultrasonic waves. From the frequency shift between the coupled and reflected waves also the flow rate of the liquid determine. Reflections in the liquid, however, occur only if there are air bubbles or impurities in this are present, so this principle mainly at contaminated liquids is used.

The Ultrasonic waves are made with the help of so-called ultrasonic transducers generated or received. For this purpose, ultrasonic transducers firmly on the pipe wall of the relevant pipe section appropriate. They are also clamp-on ultrasonic flow measurement systems available in which the ultrasonic transducer, z. B. with a clamping lock to be pressed against the pipe wall.

As Magnetic inductive flow measurement also includes ultrasound Flow meters are known, the one in a support tube having introduced liners.

at Flowmeters that work according to the Coriolis principle, are conventionally, except for very small sizes funnel-shaped reducers before and after actual measuring tube attached to the measuring tube with smaller nominal size in a piping system with a larger nominal diameter fit. So there is a change in the cross section in size and partly the shape before the actual Measuring tube instead. These cross-sectional changes lead to a pressure drop, English pressure-drop called. At the measuring tube changes the inside diameter usually does not.

Also Coriolis flowmeters are used in industrial metrology for measuring a flow of a medium, for. B. a liquid or a gas, used in a pipe section.

Coriolis Flowmeters generally have a measuring tube which extends is located in the pipe section in the measuring operation and from the medium is flowed through. The measuring tube is set in vibration. The vibration of the measuring tube is through the flowing through Fluid influences. Measuring tube and liquid together form an oscillatory system that in the Usually excited at its resonant frequency. The resulting Oscillation movement of the measuring tube is usually by two arranged on the measuring tube vibration sensors detected whose Sensor signals received and processed by a signal processing become. Based on the processed sensor signals, the flow becomes certainly. The sensor signals have a frequency equal to one Frequency of the vibration of the measuring tube is. They are, however, against each other phase. The phase shift is a measure of the Flow of the medium in the measuring tube. Coriolis flowmeters usually measure the mass flow through the measuring tube.

Inlet and outlet sections in the sense of electromagnetic flowmeters, ultrasonic or vortex flowmeters are not required for Coriolis flowmeters. Coriolis flowmeters are insensitive to, for. B. by turbulence, disturbed flows, in contrast to the other measurement principles mentioned. They can be used directly after curvatures. Therefore, as an inlet or outlet section of the Coriolis Flow meter only the respective reducer before or after the actual measuring tube plus a short section of the pipe on the measuring tube facing away from the respective reducer referred. Inlet and outlet sections of a Coriolis flowmeter are therefore not subject to the same criteria as the other measurement principles mentioned.

at many commercially available flowmeters, such as The Promass F devices from Endress + Hauser the reducers, which are not the actual measuring tube belong, part of the meter. Now the meter is supposed to be extended by a short range. The length of this Range and thus the length of the inlet and outlet sections depend on the nominal diameter of the respective measuring device from. The nominal diameter of these pipe sections is equal to the nominal size of the piping system into which the Coriolis flowmeter is used and whose length before or after the funnel-shaped Reducers should be about the size of the nominal diameter. For a measuring device with nominal diameter DN250 the length of the Measuring device on both sides by about 25 cm. Inlet and outlet sections of Coriolis flowmeters So these are the pipe sections before and after the actual Measuring tube containing a nominal diameter change.

at magnetic inductive measuring instruments, ultrasonic or vortex flowmeters does not count the inlet / outlet to the meter and is therefore used by the manufacturers of measuring instruments, if at all, sold only as an accessory.

at So Coriolis flowmeters are much less about reduction of pipeline routes before or after the measuring tube, rather than the reduction in pressure drop caused by the cross-sectional changes.

For Coriolis flowmeters, z. B. from the EP068571261 , Distributor known, which serve the division of a guided in a pipeline flow on at least two pipes, in particular measuring tubes. Especially when dividing a single stream into several measuring tubes, there is the problem of a significant pressure drop.

Out the prior art is also known, longitudinal grooves for flow optimization in the sense of reducing the use turbulent frictional resistance. There are many Patents for longitudinally grooved surfaces of wings or hulls of aircraft and for other overflowed or perfused bodies and patents describing how to obtain these grooves are.

A slide is in the WO2004060662A1 described which has parallel grooves in a certain direction. This film can be applied to various surfaces and thus optimize flow characteristics of a fluid flowing over the surface in the longitudinal direction of the grooves. An attachment of this film in a tube is, especially for small diameters, very expensive and difficult. In piping systems that transport media that may be subject to temperature and pressure fluctuations, the connection between the pipe wall and the film must have special properties. The film itself must have against the flowing medium certain characteristics, such. As chemical inactivity or chemical resistance, especially in hygiene applications. A detachment of the film, in particular caused by temperature fluctuations or pressure surges, is to be prevented. The WO2004060662A1 does not, however, provide information that suggests a solution to this problem. Furthermore, such a film is not or only partially suitable to be mounted in a, changing its cross-section pipe.

In the WO03087251A1 discloses a micro-grooved protective film, which is used in particular for the protection of a vehicle paint. Methods for producing this micro-grooved protective film are explained in detail. Such a protective film is applied with the grooved surface on the surface to be protected. Due to the special shape of this protective film adheres to uneven surfaces such. B. tubular inner walls, and prevents, for example, a detachment with temperature fluctuations. However, grooves or microgrooves on the surface of the protective film, which faces away from the surface on which the protective film is applied, are not proposed. A change of flow characteristics of a medium flowing over it are therefore not possible. Again, the problem of fixing biological organisms is not dealt with here.

The US4418578 shows a vortex flow meter with longitudinal grooves on the side facing the measuring medium side of the pipe wall to reduce turbulence and disturbances in the flowing medium. However, the longitudinal grooves are only provided in the measuring tube. As a result, caused by curvatures or cross-sectional changes Strömungsverwirbelungen or caused by cross-sectional changes pressure losses before the actual measuring tube is not significantly reduced. A significant shortening of the inlet / outlet sections is therefore not possible. The problem of biofouling is also not addressed.

Also nanostructured surfaces, keyword lotus effect, are already known to deposit remove dirt quickly and easily. An example of this is in the US6435025 shown. However, such nanostructured surfaces are neither suitable for calming the flow of the measuring medium after bends or cross-sectional changes, or for preventing or minimizing pressure losses, nor for preventing the settling of biological organisms on the surface.

Of the Invention is therefore based on the object, a device for Determination and / or monitoring of the flow of a To suggest measuring medium through a measuring tube, which leads to a reduction the inlet and outlet sections before or after a measuring tube and / or to reduce accumulations of biological organisms leads in the pipe system.

The Task is solved in that the measuring tube from a Polymer consists and flow parallel grooves in one Has measuring medium facing side or that the measuring tube with a introduced in the lumen, consisting of a polymer, tubular Liner is lined for guiding the measuring medium, which flow-parallel grooves in the measuring medium facing Side has.

According to one advantageous development of the invention Device, the measuring tube is substantially flow orthogonal Ridges in the side facing the medium to be measured or in the lumen introduced liner has substantially flow orthogonal Scored in the side facing the medium to be measured, wherein the in significant flow orthogonal grooves in cross section in assume substantial trapezoidal shape and the width of the essential flow orthogonal grooves is small in the Comparison to the width of the flow-parallel grooves and / or wherein the depth of the substantially flow orthogonal Scoring is small, compared to the depth of the flow parallel Cried.

A additional embodiment of the invention Device is that the flow orthogonal grooves and the flow parallel grooves in size, Shape and / or surface texture over the Pipe diameter and / or vary over the pipe length.

Farther the object is achieved in that a tubular Element trained measuring tube inlet and / or as a tubular Element formed measuring tube outlet flow parallel Has grooves in the side facing the medium to be measured. The inventive Device is inexpensive to manufacture, can for different applications from dedicated materials be prepared and allows in addition to a reduction of Pipe lengths and less influence on the Flow through the use of the meter, a much less effort to clean the pipes.

The essential idea of the invention is that through the longitudinal grooves the flow or the flow is optimized so far, that the inlet and / or outlet sections for flow meters, in particular for magnetic inductive flowmeters or for flowmeters based on work by ultrasound or by the vortex principle, reduced in size can be and the pressure loss in the measuring medium, by Cross-sectional changes before or after a flowmeter, especially with Coriolis flowmeters caused is, can be substantially reduced. Furthermore, by the longitudinal grooves the pollution in the pipeline and the deposits or fixings of biological organisms in the pipeline is greatly reduced.

The resulting measurement errors are reduced to a minimum and At the same time, the reliability of the measuring system is high reached. By reducing the pipe lengths and through the extension of the maintenance and cleaning intervals There are significant cost savings.

According to one further advantageous embodiment of the invention Device has the measuring tube flow-parallel grooves in the side facing the medium to be measured.

The Depth and the distances of the individual grooves depend strongly depends on the operating conditions of the device. So have next the flow velocity of the measuring medium and the longitudinal position the tire in the pipe, also the properties of the measuring medium itself, z. As its viscosity, great influence on the optimal design of the grooves.

After a further very advantageous development of the device according to the invention, the flow-parallel grooves are worked out according to their use parameters in size and shape. Their shape and the other geometric parameters result from a function of viscosity of the measured medium v and the flow velocity of the measuring medium u or the resulting Reynolds number Re and from the density ρ, the pressure p, the tube diameter D, the tube length L and the Position x of the grooves in the direction of flow in the tube, ie its longitudinal position, the acceleration a, respectively the gravitational acceleration g and the surface roughness R. The values of pressure, density, velocity, position or whose changes are averaged over the pipe length and / or the current values are assumed.

The Dimensions of the grooves are roughly in the range of a few Micrometers to several hundred micrometers. Therefore, the scores become also called microgrooves. They usually have one essentially constant shape and size over their length on.

An advantageous embodiment of the variant according to the invention consists in that the size and shape of the grooves changes over the length of the pipeline, ie that the position of the grooves in the pipeline is decisive for the shape and size of the grooves. An exact formula for calculation of the optimal depth should not be given here. The geometric size s, as in 3 shown, calculated as a function of said factors. s = f (v, u, ρ, p, D, L, x, a, R) and s = f (dv, du, dρ, dp, dD, L, x, da, R).

Next regular, lamellar microstructures as surfaces with high antifouling activity Substrates of elastic material and low surface energy from 10 to 50 mN / m. Moreover, it depends on the Roughness or on the roughness.

materials high surface energy are easily absorbed by materials low surface energy covers or wets, but not the other way around. As a rough rule can apply that materials with strong bonds, that is usually with high melting and boiling point, higher surface energies than weaker have bound materials.

numerous Scientific studies prove that biological Organisms less common on a grooved surface fix. This effect is amplified many times over when the grooves on the surface have a certain "softness" have.

Measurements useful against the settling of biological organisms are in the mid-micron range, depending on the conditions of use and the medium of measurement. The depth of a groove is up to 1 mm. The distance between the grooves to each other is at most 2 mm, in particular depths are less than 0.06 mm and distances of the grooves to each other less than 0.08 mm. The minimum depth of the grooves is 0.02 mm and the smallest distance is 0.01 mm. A depth greater than 0.03 mm and a distance of at least 0.02 mm are particularly effective. For the optimization of the flow, the grooves preferably have a depth of less than 5 mm, in particular less than 2 mm. At the same time, the grooves have spacings of up to 10 mm, in particular not more than 4 mm. The minimum depth of the grooves is 0.01 mm, preferably use at least 0.02 mm. The minimum distance is 0.01 mm, distances from 0.02 mm are particularly effective. This results in the preferred dimensions of 0.01 to 10 mm for groove pitch and depth. The distance of the grooves is measured from the middle of the respective grooves, as in 3 shown.

A particularly advantageous embodiment of the invention Device suggests that the materials used a certain elasticity or compliance, so one have certain "softness" which is a positive contribution for preventing or reducing the setting of biological Organisms supplies. These materials are sufficiently pressure resistant for the respective applications.

in the use of the device according to the invention can multiaxial stress states on the grooved surface occur. An exact description of the material behavior under These circumstances are extremely difficult and thus leaves no indication of a few, verifiable Characteristics too. Furthermore, there are a number of mechanical Hardness tests and thus many special material characteristics. Therefore, neither values for the mechanical pressure or tensile strength nor for the hardness of the material be specified. Also on the specification of material characteristics such as z. B. modulus of elasticity or Poisson number is omitted.

Advantageous Isotropic materials are used whose behavior under pressure which is similar to the polymer materials mentioned. alternative can also stainless steels, such as. B. nickel-based alloys, be used advantageously.

An advantageous embodiment of the embodiment of the solution according to the invention can be seen in that the surfaces of the grooves have a certain roughness or are themselves nanostructured. In the so-called lotus effect, elevations are up to 100 μm high and up to 200 μm apart. Preferably, elevations are used with a maximum of 20 microns in height. The minimum height is 1 μm. Preferably, elevations are used with a height greater than 5 microns. Further preferably, their distance is up to 50 microns to each other. The minimum distances of the elevations to each other are 1 micron, preferably distances from 5 microns to each other. Such a surface texture is z. B. by a layer of paint or paint with nanoparticles or by vapor deposition or spraying appropriate particles to achieve. Of course, the nanoparticles have a size which does not significantly alter the corrugated structure in its shape or negatively influence the function of the flow optimization of the corrugated structure. For this, the nanoparticles have a characteristic mitt The size of a maximum of 25% of the Riefebreite, preferably they are less than 10% of the Riefebreite, in particular they are less than 5% of the Riefenbreite.

A further advantageous embodiment of the invention can be seen therein that the measuring tube inlet designed as a tubular element is, with a diameter, the diameter over the Length of the measuring tube inlet from the inlet side to the Outlet side can vary in size and shape and / or that the measuring tube outlet as a tubular Element is designed with a diameter, wherein the diameter over the length of the measuring tube outlet from the inlet side to can vary in size and shape to the outlet side. As a result, for example, a measuring tube with a smaller nominal size to a pipeline with correspondingly larger nominal width connectable. The grooves in these conical tubular Elements contribute significantly to the reduction of the so-called pressure drops.

A further advantageous embodiment of the invention is based on the measuring tube inlet or the measuring tube outlet is designed as a distributor piece which is a single stream of the medium to at least two measuring tubes divides or one on at least two measuring tubes split flow combined into a single stream. To An inlet manifold has at least one bore on the inlet side and at least two holes on the outlet side on. An outlet manifold, however, has at least two holes on the inlet side and at least one hole on the exhaust side. Preferably, the measuring tube inlet is so designed as an inlet manifold and the measuring tube outlet is configured as an outlet manifold, with at least two Measuring tubes, in particular parallel and straight measuring tubes, in particular same width and same wall thickness, at each both ends in parallel holes in the inlet manifold or are fixed in parallel bores in Auslassverteilerstück. This is a, in particular uniform distribution, from an incoming flow to at least two measuring tubes Ensures the union of the fluid into a single stream. The Measuring tubes are thus fluidically through the manifold connected in parallel. The shape of such a manifold is very complex. The known forms of the prior art are most already optimized aerodynamically. Another Improvement is through the use of inventive Riefen to expect.

In a particularly preferred embodiment of the invention is provided that the flow parallel grooves in Cross section assume substantially trapezoidal shape. Sharp corners and to produce edges in the micrometer range, in particular with the manufacturing processes listed below, difficult or only very expensive possible. Therefore affect certain radii or curves the invention is not. In a preferred, below production methods, the grooves are by means of an embossing tool which has wires, in particular with a wire mesh, baked. As a round Wire is used is an advantageous embodiment of the Invention in the fact that the grooves in cross-section round shape accept.

A expedient embodiment of the solution the invention is that the measuring tube inlet and / or the measuring tube outlet and / or the measuring tube substantially flow orthogonal Has grooves in the side facing the medium to be measured. you are preferably at an angle of 90 ° to the flow parallel Rows arranged. However, this is only a guide for give the alignment of the wells. There are different angles, depending on application conditions, between 60 ° and 120 ° possible.

According to an advantageous embodiment of the invention, it is proposed that the substantially flow-orthogonal grooves assume a substantially trapezoidal cross-sectional shape and that the width of the substantially flow-orthogonal grooves is small compared to the width of the flow-parallel grooves and / or the depth of the grooves significant flow orthogonal grooves is small, compared to the depth of the flow parallel grooves. The flow orthogonal grooves have a positive effect on the antifouling properties of the surface and are not deeper than the flow parallel grooves, otherwise a negative effect on the flow properties of the surface can occur. At the same or less depth, the flow orthogonal grooves provide little or no contribution to improving the flow of the measuring medium. Their distance from each other is preferably equal to the distance of the flow parallel grooves or slightly larger. Otherwise, the same dependencies apply to the flow orthogonal grooves, but in different ways, in terms of size and shape as disclosed for the flow parallel grooves. This will be in 4 explained in more detail.

A further advantageous embodiment of the device according to the invention is that the measuring tube inlet and / or the measuring tube outlet and / or the measuring tube of a polymer, in particular hard rubber, polyurethane or fluorinated plastics, such. As PFA or PTFE, exist, as these materials have good chemical and mechanical properties and good processability or that the measuring tube inlet and / or the measuring tube and / or the measuring tube in ih rem lumen introduced from a polymer, in particular hard rubber, polyurethane or fluorinated plastics, such. As PFA or PTFE, existing, tubular liner for guiding the medium to be measured.

A further advantageous embodiment of the invention The solution is that the measuring tube inlet and / or the measuring tube outlet and / or the measuring tube made of a substantially metallic material consist.

A Variant of the solution according to the invention is that the pipe or the measuring tube and / or the Measuring tube inlet and / or the measuring tube outlet from a non-ferrous metal or a non-ferrous metal alloy. These materials have advantages for various applications, e.g. B. they are not magnetic and in many applications such. B. Pharmacy or food chemistry can be used.

A advantageous embodiment of the invention Solution is that the flow parallel and / or flow orthogonal grooves produced by a process that is selected from the group that shapes, loops, Removal, cutting and etching includes.

A very advantageous variant of the invention Device is to be seen in that the flow parallel and / or flow orthogonal grooves using a casting process, in particular a pressure or injection molding process are made. In particular, in a pipeline or input and / or Outlet lines or a measuring tube made of polymer or an embedded Liner made of polymer.

A further advantageous embodiment of the invention, that the flow parallel and / or flow orthogonal Scored using a film contact imaging method or a electrochemical deposition process are made.

A further advantageous embodiment of the invention Device is to be seen in that the flow parallel and / or flow orthogonal grooves using a pressing process are made.

A very advantageous variant of the invention Solution is to see that the flow parallel and / or flow orthogonal grooves using a baking process, laser cutting process or a laser burning process are made. Branding can especially with a Wire mesh done.

Of Furthermore, a combination of the mentioned methods is conceivable.

A very advantageous embodiment of the invention Device is that a film on the measuring medium facing Side of the measuring tube inlet and / or the measuring tube outlet and / or is attached to the measuring tube, which the flow parallel and / or the flow orthogonal grooves on the measuring medium already facing side of the film already contains. The foil consists preferably of elastic material and is simple and cost-effective to apply.

however is at conically extending tubular elements a Applying a foil is not possible or very difficult. Even with pipes with small diameters, this is expensive. Therefore In such embodiments, a liner with grooves is preferably drawn in.

The Invention and selected embodiments will be explained in more detail with reference to the following drawings. For simplicity, identical parts in the drawings with the the same reference numerals have been provided. It shows

1 a sectional view of a measuring tube with flow-parallel grooves,

2 a measuring tube between a measuring tube inlet and a measuring tube outlet,

3 several detailed representations of cross-sections of different groove shapes as a function of geometry parameters s,

4 perspective a surface with flow-parallel and flow orthogonal grooves,

5 a trapeze.

In the sectional view in 1 a measuring tube 1 with flow-parallel grooves 3 in the measuring medium 2 facing side of the measuring tube 1 , the measuring tube exists 1 from a carrier tube 6 with a liner incorporated therein 5 , They are only grooves parallel to the flow 3 shown. Flow orthogonal grooves 4 are not shown. At the measuring tube 1 it is a tube which is approximately in cross section in shape and size approximately over its length. The flow-parallel grooves 3 take a triangular shape in cross section. This is an extreme expression of a trapezoidal form.

2 shows a measuring tube 1 with a conical measuring tube inlet 8th and a conical measuring tube outlet 9 , Here is straight measuring tube 1 shown. The measuring tube 1 However, it can also be bent or made variable in its cross-section. The inner diameter 14 of the pipe system thus varies over the length of the pipe system. For reasons of clarity, attention was given to the representation of grooves both in the case of the measuring tube inlet 8th and at the measuring tube outlet 9 , as well as the measuring tube 1 self-dispensed. Also, a liner or an introduced film are not shown. The inlet side of the measuring tube 1 is also the outlet side 10 the measuring tube inlet and equally is the outlet side of the measuring tube 1 the inlet side 11 of measuring tube outlet.

In 3 Several detailed representations of cross-sections of various Riefenformen are shown. The grooved surfaces are shown for simplicity, an approximation of a sufficiently large pipe diameter with comparatively very small grooves. 3 will be together with the in 5 illustrated trapezoid and its determining geometry parameters explained. b indicates the width of the groove, which is advantageously between 0 and 2 mm. In relation to 5 corresponds to b of the second trapezoid base side w between the trapeze points C and D. By definition, a trapezoid consists of two parallel sides called trapezoidal base sides, here marked u and w, and two further sides, here v and z, which are at the angles α, δ and β, γ connect the trapezoid base sides into a polygon and are called trapezoidal legs. Not considered here is the pipe bend. This leads to curved sides. Furthermore, a depth t varying over the groove width b is conceivable, with which the side w is no longer parallel to u, as in FIG 3f shown. The angles α, δ, β, γ can be of different sizes. They largely determine the shape of the ridge, but are not included for the sake of simplicity 3 added.

B is advantageously dependent on the groove spacing s, b = f (s). t marks the groove depth, which is the trapezoid height h in 5 and t is also advantageously dependent on s, t = f (s). In an alternative embodiment, the scoring shape and the geometry parameters b, s, t depend on the different parameters determined by the respective conditions of use.

3a shows a rectangular cross-sectional profile of a grooved surface, wherein the width of the grooves b and their distance s, which is measured from the center of the respective groove to adjacent, are almost equal, resulting in a very thin web between the grooves. This is an extreme form of a trapezoid. Another is in 3b shown. The grooves take in cross-section triangular shape. The length of the trapezoid base side u is zero. Without the limitation that the trapezoid base sides u and w must be parallel, any side or angle in the trapezoid can become zero.

The 3c . 3d and 3e show further embodiments.

In 3f is a profile to see, where not the theoretical cross-section is shown, but the technically feasible implementation. The corners and edges are rounded, so the trapeze angle and the angles to the surrounding edges are not sharp but round. Thus, with small grooves, a round profile can also be created.

The profiles apply equally to flow-parallel and flow-orthogonal grooves. For distinction, the geometry parameters are given an index, as in 4 described.

4 shows in perspective a surface with flow-parallel and flow orthogonal grooves. It is, as previously in 3 and for the sake of clarity, the grooved surface is shown as a flat surface. The width b _o and the depth t _{o of} the flow orthogonal grooves are dependent on the distance s _o , which in turn represents a function of the above-mentioned parameters or they are dependent on the geometry parameters of the flow-parallel grooves, s _o = f (s _p ). It is shown that the width b _o and the depth t _{o of} the flow orthogonal grooves are small compared to the width b _p and the depth t _{p of} the flow-parallel grooves. The trapezoidal grooves here have a rectangular cross-section.

1

measuring tube

2

measuring medium

3

flow parallel groove

4

strömungsorthogonale groove

5

liner

6

support tube

7

radii

8th

Measuring tube inlet

9

Measuring tube outlet

10

outlet of the measuring tube inlet

11

inlet side of measuring tube outlet

12

inlet side of the measuring tube inlet

13

outlet of measuring tube outlet

14

Inner diameter of the pipe system

15

manifold

A

first Trapezeckpunkt

B

second Trapezeckpunkt

C

third Trapezeckpunkt

D

fourth Trapezeckpunkt

b

cried width

b _o

width the flow orthogonal groove

b _p

width the flow-parallel groove

H

trapeze height

s

cried distance

s _o

distance the flow orthogonal groove

s _p

distance the flow-parallel groove

t

groove depth

t _o

depth the flow orthogonal groove

t _p

depth the flow-parallel groove

u

first Trapezoid base side

v

first trapezoidal leg

w

second Trapezoid base side

z

second trapezoidal leg

α

first keystone angle

β

second Trapeze angle third Trapezwinkel fourth Trapezwinkel

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 068571261 [0024]
• - WO 2004060662 A1 [0026, 0026]
• WO 03087251 A1 [0027]
• US 4418578 [0028]
• - US 6435025 [0029]

Cited non-patent literature

• - Flow Manual of Endress + Hauser Flowtec AG, 4th edition of 2003, on pages 55 to 195 [0002]

Claims (13)

Measuring tube ( 1 ), in particular for magnetic inductive flow measurement, characterized in that the measuring tube ( 1 ) consists of a polymer and flow-parallel grooves ( 3 ) in a measuring medium ( 2 ) facing side or that the measuring tube ( 1 ) with an introduced in the lumen, consisting of a polymer, tubular liner ( 5 ) for guiding the measuring medium ( 2 ), which flow-parallel grooves ( 3 ) in the measuring medium ( 2 ) facing side. Measuring tube ( 1 ) according to claim 1, characterized in that the measuring tube ( 1 ) substantially flow orthogonal grooves ( 4 ) in the measuring medium ( 2 ) facing side or that the introduced in the lumen liner ( 5 ) substantially flow orthogonal grooves ( 4 ) in the measuring medium ( 2 ) facing side. Measuring tube ( 1 ) according to claim 2, characterized in that the flow-parallel grooves ( 3 ) assume in cross-section substantially trapezoidal shape and / or the substantially flow orthogonal grooves ( 4 ) assume in cross-section substantially trapezoidal shape, wherein the width (b _o ) of the substantially flow orthogonal grooves ( 4 ) is small compared to the width (b _p ) of the flow-parallel grooves ( 3 ) and / or wherein the depth (t _o ) of the substantially flow orthogonal grooves ( 4 ) is small compared to the depth (t _p ) of the flow-parallel grooves ( 3 ). Device for determining and / or monitoring the flow of a measuring medium ( 2 ) through a measuring tube ( 1 ), characterized in that a tubular inlet formed as a tubular element ( 8th ) and / or designed as a tubular element measuring tube outlet ( 9 ) flow-parallel grooves ( 3 ) in the measuring medium ( 2 ) facing side. Apparatus according to claim 4, characterized in that the measuring tube ( 1 ) flow-parallel grooves ( 3 ) in the measuring medium ( 2 ) facing side. Apparatus according to claim 4 or 5, characterized in that the measuring tube inlet ( 8th ) is designed as a tubular element, with a diameter, wherein the diameter over the length of the measuring tube inlet ( 8th ) from the inlet side ( 12 ) to the outlet side ( 10 ) may vary in size and shape and / or that the measuring tube outlet ( 9 ) as a tubular element with a diameter ( 14 ), wherein the diameter ( 14 ) over the length of the measuring tube outlet ( 9 ) from the inlet side ( 11 ) to the outlet side ( 13 ) may vary in size and shape. Device according to claims 4 to 6, characterized in that the measuring tube inlet ( 8th ) or the measuring tube outlet ( 9 ) as a manifold ( 15 ), which divides a single stream of the measuring medium into at least two measuring tubes or combines a flow divided into at least two measuring tubes into a single stream. Device according to claims 4 to 7, characterized in that the flow-parallel grooves ( 3 ) assume a substantially trapezoidal shape in cross-section. Device according to claims 4 to 8, characterized in that the measuring tube inlet ( 8th ) and / or the measuring tube outlet ( 9 ) and / or the measuring tube ( 1 ) substantially flow orthogonal grooves ( 4 ) in the side facing the medium to be measured. Apparatus according to claim 9, characterized in that the substantially flow orthogonal grooves ( 4 ) assume a substantially trapezoidal cross-section and that the width (b _o ) of the substantially flow orthogonal grooves ( 4 ) is small compared to the width (b _p ) of the flow-parallel grooves ( 3 ) and / or that the depth (t _o ) of the substantially flow orthogonal grooves ( 4 ) is small compared to the depth (t _p ) of the flow-parallel grooves ( 3 ). Device according to claims 4 to 10, characterized in that the measuring tube inlet ( 8th ) and / or the measuring tube outlet ( 9 ) and / or the measuring tube ( 1 ) consist of a substantially metallic material. Device according to claims 4 to 11, characterized in that the measuring tube inlet ( 8th ) and / or the measuring tube outlet ( 9 ) and / or the measuring tube ( 1 ) consist of a polymer or that the measuring tube inlet ( 8th ) and / or the measuring tube outlet ( 9 ) and / or the measuring tube ( 1 ) introduced into its lumen, consisting of a polymer, tubular liner ( 5 ) for guiding the measuring medium ( 2 ) exhibit. Device according to claims 4 to 12, characterized in that a film on the side facing the measuring medium side of the measuring tube inlet ( 8th ) and / or the measuring tube outlet ( 9 ) and / or the measuring tube ( 1 ), which the flow-parallel and / or the flow orthogonal grooves ( 3 . 4 ) on the measuring medium ( 2 ) facing side of the film already contains.