# Patent

## Title
Measuring system with a flow conditioner for flow profile stabilization

## Abstract

A measuring system is inserted into the course of a process line for a flowing medium and includes a measuring transducer with a measuring tube for conveying the medium and with a sensor arrangement for generating at least one measurement signal influenced by a measured variable of the medium. The measuring tube shows a smaller flow cross section than a supply segment of the process line, connected to the inlet end of the measuring system. The measuring system further includes a flow conditioner, arranged at the inlet end of the measuring tube and mediating between the measuring tube and the supply segment. The flow conditioner shows a lumen tapering towards the measuring tube, and includes at least two inner edges arranged upstream of its outlet end and protruding into the lumen of the flow conditioner. Between the first inner edge and the second inner edge, there extends additionally, a first guide surface of the flow conditioner. Moreover, the second inner edge bounds a second guide surface extending towards the outlet end of the flow conditioner and serving for guiding medium flowing in the flow container during operation.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application is a Continuation-in-Part of U.S. patent application Ser. No. 11/826,993 filed on Jul. 19, 2007 and U.S. patent application Ser. No. 11/826,992 filed on Jul. 19, 2007; and is a nonprovisional application which claims the benefit of U.S. Provisional Application Ser. No. 61/006,216 filed on Dec. 31, 2007.


FIELD OF THE INVENTION
The invention relates to a measuring system for measuring with a measuring transducer at least one measured variable, especially a mass flow, e.g. mass flow rate, density, viscosity, pressure, or the like, of a medium flowing in a process line, as well as to a flow conditioner mediating between the measuring transducer and the process line.
BACKGROUND OF THE INVENTION
In the field of industrial process measurements technology, especially also in connection with the automation of chemical or manufacturing processes, for registering process-describing, measured variables, and for producing measurement signals representing these, measuring systems installed near the process are used. Such measuring systems are mounted either directly on, or in, a process line, for instance a pipeline, through which medium is flowing. The variables to be measured can include, for example, mass flow, volume flow, flow velocity, density, viscosity, temperature, or the like, of a liquid, powdered, vaporous, or gaseous, process medium conveyed or held in such a process line.
Such measuring systems include, among others, those in which in-line measuring devices with magneto-inductive transducers are used, or transducers which evaluate the travel time of ultrasonic waves emitted in the flow direction, especially measuring transducers functioning according to the Doppler principle, or vibration-type transducers, especially Coriolis mass flow transducers, density transducers, or the like. Essentials of construction and functioning of magneto-inductive sensors is sufficiently described e.g. in EP-A 1 039 269, U.S. Pat. No. 6,031,740, U.S. Pat. No. 5,540,103, U.S. Pat. No. 5,351,554, U.S. Pat. No. 4,563,904; for ultrasonic sensors see e.g. U.S. Pat. No. 6,397,683, U.S. Pat. No. 6,330,831, U.S. Pat. No. 6,293,156, U.S. Pat. No. 6,189,389, U.S. Pat. No. 5,531,124, U.S. Pat. No. 5,463,905, U.S. Pat. No. 5,131,279, U.S. Pat. No. 4,787,252. Moreover, this background on these topics is adequately known to those skilled in the art, so that a detailed explanation can be omitted here. Further examples of such measuring systems known per se to those skilled in the art, especially systems made up of compact, in-line measuring devices, are explained in detail in EP-A 984 248, GB-A 21 42 725, U.S. Pat. No. 4,308,754, U.S. Pat. No. 4,420,983, U.S. Pat. No. 4,468,971, U.S. Pat. No. 4,524,610, U.S. Pat. No. 4,716,770, U.S. Pat. No. 4,768,384, U.S. Pat. No. 5,052,229, U.S. Pat. No. 5,052,230, U.S. Pat. No. 5,131,279, U.S. Pat. No. 5,231,884, U.S. Pat. No. 5,359,881, U.S. Pat. No. 5,458,005, U.S. Pat. No. 5,469,748, U.S. Pat. No. 5,687,100, U.S. Pat. No. 5,796,011, U.S. Pat. No. 5,808,209, U.S. Pat. No. 6,003,384, U.S. Pat. No. 6,053,054, U.S. Pat. No. 6,006,609, U.S. Pat. No. 6,352,000, U.S. Pat. No. 6,397,683, U.S. Pat. No. 6,513,393, U.S. Pat. No. 6,644,132, U.S. Pat. No. 6,651,513, U.S. Pat. No. 6,880,410, U.S. Pat. No. 6,910,387, US-A 2007/0163361, US-A 2005/0092101, WO-A 88/02,476, WO-A 88/02,853, WO-A 95/16,897, WO-A 00/36,379, WO-A 00/14,485, WO-A 01/02816 or WO-A 02/086 426, among others.
For registering the respective measured variables, measuring systems of the type in discussion here include a corresponding transducer, which is inserted into the course of a process line conveying a medium, in order to produce at least one measurement signal, especially an electric signal, representing the primarily measured variable as accurately as possible. To this end, the measuring transducer normally includes a measuring tube, which is inserted into the course of the pipeline and serves for conveying flowing medium, and a corresponding physical-to-electrical sensor arrangement. The sensor arrangement, in turn, includes at least one sensor element reacting primarily to the variable to be measured, or to changes of the same, in order to produce, during operation, at least one measurement signal appropriately influenced by the measured variable.
For further processing or evaluation of the at least one measurement signal, the transducer is additionally connected with a measuring electronics appropriately suited for this purpose. The measuring electronics, communicating with the measuring transducer in suitable manner, produces, during operation of the measuring system, at least at times, using the at least one measurement signal, at least one measured value instantaneously representing the measured variable, thus, for example, a measured value of mass flow, volume flow, density, viscosity, pressure, temperature, or the like.
To accommodate the measuring electronics, such measuring systems additionally include an appropriate electronics housing, which, as proposed e.g. in U.S. Pat. No. 6,397,683 or WO-A 00/36 379, can be arranged remotely from the measuring transducer and connected with it only by means of a flexible cable. Alternatively, however, as also shown e.g. in EP-A 903 651 or EP-A 1 008 836, for forming a compact in-line measuring device (for example a Coriolis mass flow/density measuring device, an ultrasonic flow-measuring device, a vortex flow-measuring device, a thermal flow-measuring device, a magneto-inductive flow-measuring device, or the like), the electronics housing can be arranged directly on the measuring transducer, or on a transducer housing separately housing the measuring transducer. In the latter case, the electronics housing, as shown, for example, in EP-A 984 248, U.S. Pat. No. 4,716,770, or U.S. Pat. No. 6,352,000, often also serves to contain some mechanical components of the measuring transducer, such as e.g. membrane-, rod-, sleeve- or tube-shaped, deformation or vibration bodies which are deformed by mechanical effects during operation; compare, in this connection, the U.S. Pat. No. 6,352,000, mentioned above.
Furthermore, measuring systems of the type described are normally connected, via a data transfer system linked to the measuring electronics, with one another and/or with appropriate process control computers, to which they transmit the measured value signals e.g. via (4 mA to 20 mA) current loop and/or a digital data bus. Serving, in such case, as data transmission systems are fieldbus systems, especially serial fieldbus systems, such as e.g. PROFIBUS-PA, FOUNDATION FIELDBUS, along with the corresponding transmission protocols. By means of the process control computers, the transmitted measured value signals can be further processed and visualized as corresponding measurement results e.g. on monitors, and/or converted into control signals for process control elements, such as e.g. magnetic valves, electric motors, etc.
As also discussed in, among others, GB-A 21 42 725, U.S. Pat. No. 5,808,209, US-A 2007/0163361, US-A 2005/0092101, U.S. Pat. No. 6,880,410, U.S. Pat. No. 6,644,132, U.S. Pat. No. 6,053,054, U.S. Pat. No. 6,644,132, U.S. Pat. No. 5,052,229 or U.S. Pat. No. 6,513,393, in-line measuring devices and, in this respect, also measuring systems of the type described, can, quite likely, have an accuracy of measurement dependent, more or less, on the type of flow. Of special interest in this connection is particularly the instantaneous character of the flow profile in the measuring tube. Considering that turbulent flows, thus flows with a Reynolds number greater than 2300, are largely similar to one another over a broad Reynolds number range, and, as a result, have a comparable effect on measurement accuracy, a high flow velocity of the medium to be measured is often desired in many measuring systems. To achieve a sufficiently high level of measuring accuracy in the case of vortex flow-measuring devices, one usually wants flows which have a Reynolds number much higher than 4000.
Thus, in the case of measuring systems of the type under discussion, it is quite usual, at least in the case of process lines of comparatively larger caliber and/or in applications with comparatively slower flowing media, to construct the measuring tube, if necessary, such that it has a smaller flow cross-section than a supply segment of the process line connected to the inlet side of the measuring system. As a result, the flowing medium experiences an acceleration in the flow direction, whereby, in turn, the Reynolds number is increased. Implementation of this principle has proven itself, especially also in the case of measuring systems which function by means of an ultrasonic measuring device, and/or a vortex flow-measuring device, and/or which are provided for the measurement of at least partially, especially predominantly or entirely, gaseous media.
Considering that, for example, the relationship between the shedding rate of vortices on a flow-opposing, bluff body and the therewith primarily to be registered, measured variable, i.e. volume flow rate or flow velocity, which relationship forms the basis upon which vortex flow-measuring devices operate, can only first be accepted as linear to an adequate degree once a Reynolds number of 20,000 has been surpassed, it may be necessary to implement a comparatively great difference between the flow cross sections of the process line and the measuring tube.
In order to create over a shortest-possible distance a transition zone which is as well-defined as possible, from the supply segment to the measuring tube with its smaller flow cross section, it is usual, as also proposed in, among others, GB-A 21 42 725, U.S. Pat. No. 5,808,209, US-A 2007/0163361, or US-A 2005/0092101, to provide in the measuring system a flow conditioner having a lumen tapering toward the measuring tube. During operation, the medium flows through such lumen. The flow conditioner is arranged on the inlet side of the measuring tube, and mediates between the measuring tube and the supply segment of the process line. An inlet-end of the flow conditioner, facing the supply segment of the process line, has, in such case, a flow cross section which is greater than the flow cross section of the measuring tube, while an outlet-end of the flow conditioner, facing the measuring tube, accordingly has a flow cross section which is smaller than that of the inlet end.
Especially in U.S. Pat. No. 5,808,209, as well as also in US-A 2005/0092101, it is further indicated in connection with the flow conditioners presented there in each case, that the transition realized between the two differently sized flow cross sections must be kept continuous and absolutely free of interruptions, such as, for example vortex-causing edges. This can be ensured to a quite satisfactory degree by relatively complex processing of the surfaces of the flow conditioner, and of the possibly present joints in the inlet region of the measuring system. However, it has been found that, despite the use of flow conditioners of the type named above, already minor disturbances of the flow in the inlet region of the measuring system, especially also in the supply segment of the connected process line located upstream of the measuring system, or in the region of the connection flange on the inlet side, which, if needed, serves to connect the supply segment and the measuring system, are associated with a significant variation of the flow conditions inside the measuring tube lumen, and, thus, with a corresponding decline in the accuracy of measurement. Superficially, a possibility for eliminating this problem is to perform a matching processing also of the inlet region of the measuring system, and thus of the supply segment of process line, or of the flange connection at the inlet. This processing, however, is practically impossible to carry out, at any rate not without further demands on the user of the measuring system. This especially is the case, because the choice of the measuring system can result from the fact that, in an existing plant, a previously-installed, and with respect to the actual flow conditions, possibly over-sized, measuring system is to be ad hoc replaced. In this respect, the actual installation conditions for the measuring system are to be considered not only unforeseeable, but also, as a practical matter, both not adaptable, and, as a result, also not controllable.
A further possibility for removing the disadvantages accompanying flow conditioners of the type being discussed is, according to US-A 2007/0163361, to be seen in forming such a flow conditioner by means of various inner cones, so that it exhibits internally, for practical purposes, a stepped contour. This inlet geometry leads to the fact that the flow near to the wall is accelerated significantly more than in the interior, whereby the flow profile finally resulting as a result thereof in the measuring tube exhibits a slight pressure dependence. Problematic in the case of this configuration of the flow profile may, however, be its dependence on flow velocity itself, as well as its, in the above sense, on occasion, too low degree of turbulence.
A further possibility for avoiding the problems connected with flow conditioners of the type being discussed is to increase the installed length of the flow conditioner, in order to achieve, already in the flow conditioner (as much as possible, in any event, already before entrance of the flow into the measuring tube), in predictable manner, a large degree of blending due to increased turbulence and/or a large degree of stabilizing of the flow. However, this can mean a considerable increase in the installed length of the total measuring system. Considering the situation named above, in which an existing, conventional measuring system is to be replaced by one with a flow conditioner connected upstream, the installed length for the measuring system is more or less predetermined, and thus an increase in the installed length of the flow conditioner is possible only within this rather limited degree.
SUMMARY OF THE INVENTION
Starting from the aforementioned disadvantages of conventional measuring systems of the type being discussed, an object of the invention, therefore, is to provide a measuring system for a flowing medium, which, in the context of shortest possible installed length, enables an increase of the Reynolds number of the flow from the process line to the measuring tube, and which, notwithstanding, has a measuring accuracy which is largely insensitive to possible disturbances in the flowing medium upstream of the measuring system, whether in the supply segment and/or in the immediate transition zone between the process line and the actual measuring system.
To achieve this object, the invention resides in a measuring system inserted into the course of a process line, especially a pipeline, for registering at least one measured variable, especially a mass flow, a volume flow, a flow velocity, a density, a viscosity, a pressure, a temperature, and/or the like, of a medium flowing in the process line, which measuring system comprises:

    
    
        A measuring transducer, including
        a measuring tube, especially a straight measuring tube, which serves for conveying medium to be measured and which has a smaller flow cross section than a supply segment of the process line connected to an inlet of the measuring system, and
        a sensor arrangement,
        having at least one sensor element reacting primarily to the variable to be registered, especially to changes of the same, and
        providing, by means of the at least one sensor element, at least one measurement signal influenced by the measured variable;
        a measuring electronics communicating with the measuring transducer and producing, at least at times, taking into consideration the at least one measurement signal, at least one measured value instantaneously representing the measured variable, especially a mass flow measured value, a volume flow measured value, a density measured value, a viscosity measured value, a pressure measured value, a temperature measured value; and
        a flow conditioner arranged at an inlet of the measuring tube, mediating between the measuring tube and the supply segment of the process line, having a lumen which tapers toward the measuring tube, and through which medium flows during operation;
        wherein an inlet end of the flow conditioner, facing the supply segment of the process line, has a flow cross section, which is greater than the flow cross section of the measuring tube, and an outlet end of the flow conditioner, facing toward the measuring tube, has a flow cross section, which is smaller than the flow cross section of the inlet end of the flow conditioner; and
        wherein the flow conditioner has, arranged upstream of its outlet end, at least a first inner edge protruding into the lumen of the flow conditioner, especially a first inner edge extending circumferentially along a directrix of the flow conditioner, and/or a circular first inner edge, as well as at least a second inner edge protruding into the lumen of the flow conditioner, especially a second inner edge extending circumferentially along a directrix of the flow conditioner, and/or a circular second inner edge, against which two inner edges medium conveyed in the flow conditioner flows during operation;
        wherein a first guide surface of the flow conditioner, especially an at least sectionally, with reference to a longitudinal axis of the flow conditioner, strongly concavely formed, first guide surface of the flow conditioner, extends between the first inner edge protruding into the lumen of the flow conditioner and the second inner edge protruding into the lumen of the flow conditioner; and
        wherein the second inner edge protruding into the lumen of the flow conditioner bounds a second guide surface of the flow conditioner, especially an essentially convex, second guide surface of the flow conditioner, serving for guiding medium flowing in the flow conditioner and extending in the direction of the outlet end of the flow conditioner.
    
    


Furthermore, the invention resides in a method for registering at least one measured variable, especially a mass flow, a volume flow, a flow velocity, a density, a viscosity, a pressure, a temperature, and/or the like, of a medium flowing in a process line, by means of a measuring system inserted into the course of the process line and having a flow conditioner connected to a supply segment of the process line, as well as a measuring transducer connected to the flow conditioner, which method includes the following steps:

    
    
        allowing the medium to be measured to flow out of the supply segment into the flow conditioner,
        accelerating the flowing medium in the direction of a longitudinal axis of the flow conditioner, and inducing at least one essentially stationary, especially also essentially locationally fixed, toroidal vortex within medium flowing in an inlet region of the flow conditioner in a manner such that a principal axis of greatest inertia of the at least one toroidal vortex essentially coincides with the longitudinal axis of the flow conditioner, and/or a longitudinal axis of a measuring tube of the measuring transducer,
        allowing the medium to be measured to flow past the at least one toroidal vortex, and allowing the medium to be measured to flow out of the flow conditioner and into the measuring tube of the measuring transducer, as well as
        producing at least one measurement signal influenced by the measured variable to be registered by application of at least one sensor element which reacts primarily to the measured variable, especially also to changes in the same,
        wherein the step of inducing the at least one, essentially stationary, toroidal vortex in the inlet region of the flow conditioner includes steps of allowing medium to flow past a first inner edge of the flow conditioner protruding into a lumen of the flow conditioner, especially a first inner edge extending circumferentially closed along a directrix of the flow conditioner, as well as allowing medium to flow past a second inner edge of the flow conditioner located downstream from the first inner edge and protruding into a lumen of the flow conditioner, especially a second inner edge extending circumferentially closed along a directrix of the flow conditioner.
    
    


In a first embodiment of the measuring system of the invention, it is provided that each of the inner edges protruding into the lumen of the flow conditioner is so constructed and arranged in the flow conditioner that it is directed essentially transversely to a longitudinal axis of the flow conditioner and/or transversely to a longitudinal axis of the measuring tube.
In a second embodiment of the measuring system of the invention, it is provided that each of the inner edges protruding into the lumen of the flow conditioner is formed circumferentially, especially circularly, and, as a result, closes on itself.
In a third embodiment of the measuring system of the invention, it is provided that the first inner edge protruding into the lumen of the flow conditioner is arranged in the vicinity, especially the immediate vicinity, of the inlet end of the flow conditioner.
In a fourth embodiment of the measuring system of the invention, it is provided that the first inner edge protruding into the lumen of the flow conditioner is arranged immediately at the inlet end of the flow conditioner.
In a fifth embodiment of the measuring system of the invention, it is provided that the first inner edge protruding into the lumen of the flow conditioner has an edge radius smaller than 2 mm, especially smaller than 0.6 mm.
In a sixth embodiment of the measuring system of the invention, it is provided that the flow conditioner is essentially circular-cylindrically shaped, at least in an inlet region.
In a seventh embodiment of the measuring system of the invention, it is provided that the measuring tube is essentially circular-cylindrically shaped, at least in an inlet region.
In an eighth embodiment of the measurement system of the invention, it is provided that the flow conditioner is essentially circular-cylindrically shaped, at least in an outlet region.
In a ninth embodiment of the measuring system of the invention, it is provided that the measuring tube, especially the circular-cylindrically shaped measuring tube, is essentially straight.
In a tenth embodiment of the measuring system of the invention, it is provided that a cross section ratio of the flow cross section of the supply segment of the process line to the flow cross section of the measuring tube is kept greater than 1.5.
In an eleventh embodiment of the measuring system of the invention, it is provided that a cross section ratio of the flow cross section of the supply segment of the process line to the flow cross section of the measuring tube is kept smaller than 10.
In a twelfth embodiment of the measuring system of the invention, it is provided that a cross section ratio of the flow cross section of the supply segment of the process line to the flow cross section of the measuring tube is kept in a range between 1.66 and 9.6.
In a thirteenth embodiment of the measuring system of the invention, it is provided that a cross section of the lumen of the flow conditioner bounded by the first inner edge protruding into the lumen of the flow conditioner is smaller than the flow cross section of the supply segment of the process line.
In a fourteenth embodiment of the measuring system of the invention, it is provided that a constriction ratio of the cross section bounded by the first inner edge to the flow cross section of the supply segment of the process line is kept smaller than 0.9.
In a fifteenth embodiment of the measuring system of the invention, it is provided that the constriction ratio of the cross section bounded by the first inner edge to the flow cross section of the supply segment of the process line is kept greater than 0.1.
In a sixteenth embodiment of the measuring system of the invention, it is provided that a constriction ratio of the cross section bounded by the first inner edge to the flow cross section of the supply segment of the process line is kept in a region between 0.25 and 0.85.
In a seventeenth embodiment of the measuring system of the invention, it is provided that a difference between the cross section ratio and the constriction ratio is kept greater than 0.5.
In an eighteenth embodiment of the measuring system of the invention, it is provided that a difference between the cross section ratio and the constriction ratio is kept smaller than 10.
In a nineteenth embodiment of the measuring system of the invention, it is provided that a difference between the cross section ratio and the constriction ration is kept greater than 0.83 and smaller than 9.5.
In a twentieth embodiment of the measuring system of the invention, it is provided that a contraction ratio of the cross section bounded by the first inner edge to the flow cross section of the measuring tube is kept greater than 1.2.
In a twenty-first embodiment of the measuring system of the invention, it is provided that a contraction ratio of the cross section bounded by the first inner edge to the flow cross section of the measuring tube is kept smaller than 5.
In a twenty-second embodiment of the measuring system of the invention, it is provided that a contraction ratio of the cross section bounded by the first inner edge to the flow cross section of the measuring tube is kept in a range between 1.3 and 3.
In a twenty-third embodiment of the measuring system of the invention, it is provided that a difference between the cross section ratio and the contraction ratio is kept greater than 0.2.
In a twenty-fourth embodiment of the measuring system of the invention, it is provided that a difference between the cross section ratio and the contraction ratio is kept smaller than 10.
In a twenty-fifth embodiment of the measuring system of the invention, it is provided that a difference between the cross section ratio and the contraction ratio is kept greater than 0.25 and smaller than 8.
In a twenty-sixth embodiment of the measuring system of the invention, it is provided that the measuring tube has a smaller caliber than a supply segment of the process line connected to an inlet of the measuring system.
In a twenty-seventh embodiment of the measuring system of the invention, it is provided that an inlet end of the flow conditioner facing the supply segment of the process line has a caliber which is greater than a caliber of the measuring tube, and an outlet end of the flow conditioner facing the measuring tube has a caliber which is smaller than the caliber of the inlet end of the flow conditioner.
In a twenty-eighth embodiment of the measuring system of the invention, it is provided that the first inner edge protruding into the lumen of the flow conditioner is formed such that an inner diameter of the inlet end of the flow conditioner is kept smaller than the caliber of the supply segment of the process line.
In a twenty-ninth embodiment of the measuring system of the invention, it is provided that a caliber ratio of the caliber of the supply segment of the process line to the caliber of the measuring tube is kept greater than 1.1.
In a thirtieth embodiment of the measuring system of the invention, it is provided that a caliber ratio of the caliber of the supply segment of the process line to the caliber of the measuring tube is kept smaller than 5.
In a thirty-first embodiment of the measuring system of the invention, it is provided that a caliber ratio of the caliber of the supply segment of the process line to the caliber of the measuring tube is kept in a range between 1.2 and 3.1.
In a thirty-second embodiment of the measuring system of the invention, it is provided that a cross section of the lumen of the flow conditioner bounded by the first inner edge protruding into the lumen of the flow conditioner has a diameter which is smaller than the caliber of the supply segment of the process line.
In a thirty-third embodiment of the measuring system of the invention, it is provided that the measuring tube has an installed length, which is greater than an installed length of the flow conditioner, so that an installed length ratio of the installed length of the flow conditioner to the installed length of the measuring tube is kept smaller than one.
In a thirty-fourth embodiment of the measuring system of the invention, it is provided that a caliber ratio of the caliber of the supply segment of the process line to the caliber of the measuring tube corresponds to at least 10% of the installed length ratio of the installed length of the flow conditioner to the installed length of the measuring tube.
In a thirty-fifth embodiment of the measuring system of the invention, it is provided that the at least one sensor element, especially a sensor element immersed in the medium during operation, is arranged, at a distance from the inlet end of the measuring tube, in and/or on, especially directly on, the measuring tube.
In a thirty-sixth embodiment of the measuring system of the invention, it is provided that the at least one sensor element is so placed, that a ratio of said distance to the caliber of the measuring tube is kept greater than one.
In a thirty-seventh embodiment of the measuring system of the invention, it is provided that the first inner edge protruding into the lumen of the flow conditioner limits an impingement surface arranged in an, especially circularly circumferentially extending, border region of the flow conditioner and serving for causing medium flowing thereon to eddy.
In a first further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the impingement surface is so arranged and oriented in the flow conditioner, that it extends, at least sectionally, essentially perpendicularly to a longitudinal axis of the flow conditioner and/or that it extends sectionally essentially perpendicularly to a longitudinal axis of the measuring tube.
In a second further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the impingement surface has, in a radial direction, a height amounting to at least 1 mm.
In a third further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the impingement surface is formed as an annular surface.
In a fourth further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the impingement surface and the inner edge are formed, at least in part, by a shoulder, especially a circular and/or self-closing shoulder, formed on the inlet of the flow conditioner.
In a fifth further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the impingement surface is formed, at least sectionally, essentially planarly.
In a sixth further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the impingement surface is so arranged and oriented in the flow conditioner that it is sectionally essentially coplanar to a cross section of the flow conditioner and/or it is sectionally essentially coplanar with a cross section of the measuring tube.
In a seventh further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the impingement surface is at least sectionally formed essentially conically.
In an eighth further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the impingement surface tapers toward the measuring tube.
In a ninth further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the impingement surface is formed widening toward the inlet end of the flow conditioner.
In a tenth further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the impingement surface and the inner edge are at least in part formed by an inner cone formed into the inlet of the flow conditioner, especially an inner cone extending to the inlet end of the flow conditioner and tapering toward the measuring tube.
In an eleventh further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the inner cone forming the impingement surface of the flow conditioner has a flank angle greater than 45°, especially greater than 60°.
In a twelfth further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the inner cone forming the impingement surface of the flow conditioner has a flank angle smaller than 90°, especially smaller than 88°.
In a thirteenth further development of the thirty-seventh embodiment of the measuring system of the invention, it is provided that the inner cone forming the impingement surface of the flow conditioner has a flank angle greater than 60° and smaller than 88°.
In a thirty-eighth embodiment of the measuring system of the invention, it is provided that the first guide surface is formed, especially predominantly or entirely, concavely with respect to a longitudinal axis.
In a thirty-ninth embodiment of the measuring system of the invention, it is provided that the second guide surface of the flow conditioner, especially a conically formed, second guide surface thereof, is formed, at least sectionally, convexly with reference to a longitudinal axis of the flow conditioner.
In a fortieth embodiment of the measuring system of the invention, it is provided that the second guide surface of the flow conditioner tapers narrower in the direction of the measuring tube.
In a forty-first embodiment of the measuring system of the invention, it is provided that the second guide surface of the flow conditioner is formed essentially conically.
In a forty-second embodiment of the measuring system of the invention, it is provided that the second guide surface and the second inner edge are formed, at least in part, by an inner cone formed at the inlet-side in the flow conditioner, especially an inner cone extending toward the outlet end of the flow conditioner.
In a first further development of the forty-second embodiment of the measuring system of the invention, it is provided that the inner cone forming the second guide surface of the flow conditioner has a flank angle greater than 2°, especially greater than 4°.
In a second further development of the forty-second embodiment of the measuring system of the invention, it is provided that the inner cone forming the second guide surface of the flow conditioner has a flank angle smaller than 45°, especially smaller than 10°.
In a third further development of the forty-second embodiment of the measuring system of the invention, it is provided that the inner cone forming the second guide surface of the flow conditioner has a flank angle greater than 4° and smaller than 10°.
In a forty-third embodiment of the measuring system of the invention, it is provided that the at least one, first inner edge protruding into the lumen of the flow conditioner limits an impingement surface of the flow conditioner arranged in a border region of the flow conditioner, especially a circularly circumferential border region, and serving to cause medium flowing thereagainst to eddy, as well as also limiting a guide surface of the flow conditioner extending toward the outlet end of the flow conditioner and serving for guiding medium flowing in the flow conditioner.
In a first further development of the forty-third embodiment of the measuring system of the invention, it is provided that the impingement surface is formed by a first inner cone formed into the inlet of the flow conditioner and extending towards its inlet end, and the guide surface is formed by a second inner cone formed into the inlet of the flow conditioner and extending toward its outlet end.
In a second further development of the forty-third embodiment of the measuring system of the invention, it is provided that the first inner cone forming the impingement surface has a flank angle greater than a flank angle of the second inner cone forming the guide surface.
In a third further development of the forty-third embodiment of the measuring system of the invention, it is provided that the first inner cone forming the impingement surface of the flow conditioner has a flank angle greater than 45°, especially greater than 60°, and smaller than 90°, especially smaller than 88°, and that the second inner cone forming the guide surface of the flow conditioner has a flank angle greater than 2°, especially greater than 4°, and smaller than 45°, especially smaller than 10°.
In a forty-fourth embodiment of the measuring system of the invention, it is provided that the at least one sensor element is formed by means of at least one piezoelectric element and/or at least one piezoresistive element.
In a forty-fifth embodiment of the measuring system of the invention, it is provided that the at least one sensor element is formed by means of at least one solenoidal coil associated with an armature.
In a forty-sixth embodiment of the measuring system of the invention, it is provided that the at least one sensor element is formed by means of at least one measuring electrode contacting medium flowing in the measuring tube and sensing electrical potentials.
In a forty-seventh embodiment of the measuring system of the invention, it is provided that the at least one sensor element is formed by means of at least one measuring capacitor reacting to changes of the measured variable.
In a forty-eighth embodiment of the measuring system of the invention, it is provided that the at least one sensor element is formed by means of at least one electrical resistance.
In a forty-ninth embodiment of the measuring system of the invention, it is provided that the at least one sensor element is subjected during operation to repeated mechanical deformation under the influence of the medium flowing in the measuring tube.
In a fiftieth embodiment of the measuring system of the invention, it is provided that the at least one sensor element is moved during operation repeatedly relative to a static rest position under the influence of the medium flowing in the measuring tube.
In a fifty-first embodiment of the measuring system of the invention, it is provided that the measuring transducer includes at least one bluff body arranged in the measuring tube.
In a fifty-second embodiment of the measuring system of the invention, it is provided that the at least one sensor element of the sensor arrangement, especially a sensor element protruding at least partially into the measuring tube, is arranged downstream of the at least one bluff body.
In a 53rd embodiment of the measuring system of the invention, it is provided that the measuring transducer is embodied as a vortex flow transducer, especially a vortex-street, flow transducer.
In a 54th embodiment of the measuring system of the invention, it is provided that the measuring transducer is embodied as a magneto-inductive, flow transducer.
In a 55th embodiment of the measuring system of the invention, it is provided that the measuring transducer is embodied as a flow transducer of vibration-type, especially a Coriolis mass flow transducer, a density transducer and/or a viscosity transducer. In a 52nd embodiment of the measuring system of the invention, it is provided that the measuring transducer is embodied as an ultrasonic flow transducer.
In a 56th embodiment of the measuring system of the invention, it is provided that a cross section of the lumen of the flow conditioner bounded by the first inner edge protruding into the lumen of the flow conditioner is greater than a cross section of the lumen of the flow conditioner bounded by the second inner edge protruding into the lumen of the flow conditioner.
In a 57th embodiment of the measuring system of the invention, it is provided that a cross section of the lumen of the flow conditioner bounded by the second inner edge protruding into the lumen of the flow conditioner is smaller than the flow cross section of the supply segment of the process line, especially smaller than the flow cross section of the inlet end of the flow conditioner.
In a 58th embodiment of the measuring system of the invention, it is provided that that a constriction ratio of the cross section bounded by the second inner edge to the flow cross section of the supply segment of the process line is kept smaller than 0.9.
In a 59th embodiment of the measuring system of the invention, it is provided that a constriction ratio of the cross section bounded by the second inner edge to the flow cross section of the supply segment of the process line is kept greater than 0.1.
In a 60th embodiment of the measuring system of the invention, it is provided that a constriction ratio of the cross section bounded by the second inner edge to the flow cross section of the supply segment of the process line is kept in a range between 0.19 and 0.78.
In a 61st embodiment of the measuring system of the invention, it is provided that a contraction ratio of the cross section bounded by the second inner edge to the flow cross section of the measuring tube is kept greater than 0.9.
In a 62nd embodiment of the measuring system of the invention, it is provided that a contraction ratio of the cross section bounded by the second inner edge to the flow cross section of the measuring tube is kept smaller than 5.
In a 63rd embodiment of the measuring system of the invention, it is provided that a contraction ratio of the cross section bounded by the second inner edge to the flow cross section of the measuring tube is kept in a range between 0.9 and 2.5.
In a first further development of the 63rd embodiment of the measuring system of the invention, it is provided that a difference between a cross section ratio of the flow cross section of the supply segment of the process line to the flow cross section of the measuring tube and the contraction ratio is kept greater than 0.2
In a second further development of the 63rd embodiment of the measuring system of the invention, it is provided that a difference between a cross section ratio of the flow cross section of the supply segment of the process line to the flow cross section of the measuring tube and the contraction ratio is kept smaller than 10.
In a third further development of the 63rd embodiment of the measuring system of the invention, it is provided that a difference between a cross section ratio of the flow cross section of the supply segment of the process line to the flow cross section of the measuring tube and the contraction ratio is kept greater than 0.4 and smaller than 8.
In a 64th embodiment of the measuring system of the invention, it is provided that the first guide surface is formed at least partially by a groove, especially a circular and/or circumferential groove, formed in the flow conditioner.
In a 65th embodiment of the measuring system of the invention, it is provided that the first guide surface is formed by an annular groove formed in the flow conditioner.
In a 66th embodiment of the measuring system of the invention, it is provided that the first guide surface is formed by an inner cone formed in the flow conditioner.
In a first embodiment of the method of the invention, such further includes a step of inducing at least one further, essentially stationary, especially essentially locationally fixed, toroidal vortex in the inlet region of the flow conditioner in such a manner that the principal axis of greatest inertia of each of the at least two toroidal vortices extends essentially parallel with the other and/or, at least when axially extended, coincides with the other.
In a second embodiment of the method of the invention, such further includes allowing medium to flow against an impingement surface of the flow conditioner opposing the flowing medium in a border region of the flow conditioner, especially a border region extending circumferentially closed along a directrix of the flow conditioner, for inducing an essentially stationary, toroidal vortex in the inlet region of the flow conditioner.
A basic idea of the invention is to improve measurement accuracy of measuring systems of the described kind not only by sufficiently accelerating the flow and so bringing such into a favorable Reynolds number range, but also by, on the one hand, largely eliminating, by means of a flow conditioner placed before the actual measuring transducer, disturbances, such as e.g. vortices introduced into the flow possibly upstream of the measuring system and entrained, such that they move with the flow, in wall-near regions, and so, on the other hand, by means of the flow conditioner, to bring about a largely disturbance insensitive flow profile for the medium flowing into the measuring transducer, namely a flow profile sufficiently well reproducible for the measuring principle. This is accomplished in the measuring system of the invention especially by producing in its inlet region at least one, essentially toroidal vortex, which, at least in steady state, is kept essentially locationally fixed. This stationary vortex acts, for the medium flowing past, practically as an additional, cross sectional constriction and, as a result, as a “virtual” nozzle, intrinsically formed within the flowing medium. A special characteristic of such a “virtual” nozzle is that it largely eliminates disturbances possibly induced in the flow upstream of the inlet region. There results downstream, practically anew, a largely undisturbed flow profile. The size and strength of the toroidal vortex even adapts to the size and strength of the incoming disturbance, so that the so-obtained, “virtual” nozzle is practically self-adapting in the sense of being an effective disturbance eliminator.
The invention is based, in such case, on the surprising discovery that a stationary, especially also essentially locationally fixed, vortex can be achieved by means of flow obstacles placed in the inlet region of the measuring system to act as defined disturbance (here two inner edges following one after the other, which are as sharp as possible and which extend circumferentially, especially circularly, as completely closed as possible, interacting with a guide surface intermediating between the inner edges, or between these and the outlet end of the flow conditioner) in a border region of the lumen through which the medium is flowing. The concave guide surface between the two inner edges (which should correspond, as much as possible, in advantageous manner, essentially to a lateral surface of a segment, especially about in the order of magnitude between a 1⁄2-segment to about a 1⁄5-segment, of a toroidal shell or a lateral surface of a similar drum body) opens for the vortex a space in which it can, protected from the remaining part of the flow, develop largely undisturbed and, thus, also in defined manner. This, in turn, promotes the locational stability of the vortex and supports, additionally, the effect that size and shape of the vortex can adapt optimally to the instantaneous flow conditions within the flow conditioner. Moreover, the second inner edge intermediating between the two guide surfaces effects a limiting of a maximum size of the vortex also in the axial direction and, consequently, provides additional stabilizing of the same.
As a result of the toroidal vortex and the flow guidance associated therewith, there is obtained, downstream of the same, a flow profile that already after a very short distance of travel in the flow conditioner, at least however upon entrance into the following measuring tube, corresponds, happily, essentially to a completely developed, turbulent, pipe-profile.
The effect of the “virtual” nozzle produced by means of the toroidal vortex can be yet further improved by bringing about, in the flow conditioner upstream of the vortex produced by means of the inner edge, a further vortex, equally as locationally fixed as possible, located possibly even immediately before the vortex produced by the inner edge. This can be achieved in the case of the flow conditioner of the invention structurally in a very simple manner by providing a clearly developed impingement surface limited by the inner edge, especially an impingement surface extending circumferentially, especially circularly, largely uniformly, around, such that it acts as an obstacle against the medium flowing thereonto, in a manner sufficient for vortex formation.
By forming two such toroidal vortices, especially ones oriented largely concentrically to one another, it is possible, on the one hand, better to trap vortices entrained in the incoming medium and so to eliminate them more effectively. On the other hand, by means of two such, sequentially arranged, concentric vortices, the contour of the so formed “virtual” nozzle effectively active for the flow has an overall convex form and accordingly for the course of the flow, especially wall-near flow portions, in the total inlet region of the measuring system, practically a concavo-convex form about approximating an S-form. This, in turn, favors, in special measure, the development of a flow profile well reproducible equally also over a wide range of application, very well suited for the following measurement. Consequently, despite possible disturbed flow in the supply segment, medium can be fed to the measuring transducer via the flow conditioner with a flow profile, which is, at least largely, similar to a calibrated situation.
Use of a flow conditioner of the present invention has, for example in the case of the above-described vortex measuring devices, among others, also the advantage that they are, despite relatively great differences between the caliber of the supply segment of the attached process line and the caliber of the measuring tube, e.g. over two nominal diameter levels, suited also for the measurement of relatively slowly flowing gases.



BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be explained in greater detail on the basis of the appended drawing, the figures of which show as follows:
FIG. 1 perspectively, in side view, a measuring system for a medium flowing in a process line;
FIGS. 2, 3 a measuring transducer working according to the vortex principle and suited for application in a measuring system of FIG. 1; and
FIGS. 4 to 6 schematically, in longitudinal sections, details of the measuring system of FIG. 1.



DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
While the invention is susceptible to various modifications and alternative forms, exemplary embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the intended claims.
FIG. 1 shows, schematically, a measuring system, which may be, to the extent required, modularly assembled. The measuring system is suited for measuring, very robustly, at least one measured variable, especially a mass flow m and/or a volume flow v and/or a flow velocity u and/or some other flow parameter of a medium, for example a liquid, a gas, a vapor, or the like, flowing in a process line (not shown) and for mapping such variable into at least one corresponding, measured value XM. The measuring system includes for such purpose at least one inline measuring device for flowing media. The measuring device is formed by means of a measuring transducer 100 suited for the intended purpose, as well as a measuring electronics electrically coupled, at least at times, therewith. Thus, the inline measuring device includes a measuring transducer 100, through which medium flows during operation, as well as an electronics housing 200, in which a measuring electronics is accommodated. The measuring electronics is electrically connected with the measuring transducer 100. The exact means of electrical connection does not need to be discussed here.
The measuring transducer 100 includes at least one measuring tube for insertion into the course of the process line. The process line can be in the form of a pipeline, for instance. The medium to be measured is allowed, during operation of the measuring system, to flow, at least at times, through the measuring tube. The inline measuring device is provided especially for producing, at least at times, at least one measurement signal influenced by at least one physical parameter, especially a flow velocity, a mass flow m, a volume flow v, a density ρ and/or a viscosity η, of the medium present in the measuring tube and, in such respect, appropriately corresponding to the measured variable. Serving, in such case, for producing the at least one measurement signal is a sensor arrangement of the inline measuring device. The sensor arrangement is arranged on the measuring tube and/or in its vicinity, and reacts, at least mediately, to changes of the at least one measured variable of the medium in a manner appropriately influencing the at least one measurement signal.
In an advantageous embodiment of the invention, the measuring electronics is further so embodied that it can, during operation of the measuring system, exchange measurement- and/or other operating-data, especially also the at least one measured value XM, with a measured value processing unit superordinated to the measuring system, especially a programmable logic controller (PLC), a personal computer and/or a workstation, via a data transmission system, for example a fieldbus system. For the aforementioned case in which the measuring system is provided for coupling to a fieldbus or other communications system, the measuring device electronics has a corresponding communications interface for data communications, e.g. for sending the measurement data to the already mentioned programmable logic controller or a superordinated, process control system. Also for this purpose, correspondingly established, standard interfaces of, for example, measurements and automation technology can be used. Moreover, also the external energy, or power, supply can be connected to the fieldbus system, and the measuring system can be supplied in the above described manner directly via the fieldbus system with energy.
In the example of an embodiment shown here, a vortex flow-measuring device serves as an inline measuring device, which, as is known, is well suited for measuring gases, and for the highly accurate registering of the physical, measured variable, especially the mass flow m, density ρ and/or viscosity η, of the medium to be measured. However, in such case, also other inline measuring devices equally established in the technology of process automation can be used, such as e.g. magneto-inductive flow meters, pressure-difference flow meters, ultrasonic flow measuring devices or the like.
The perspective, general views of FIGS. 2 and 3 of an example of an embodiment of a vortex measuring transducer operating according to the vortex principle show, on the one hand, as seen in the direction of flow (FIG. 2) and on the other hand as seen counter to the direction of flow (FIG. 3), a partially sectioned measuring transducer 1 of a vortex flow-measuring device having affixed to a wall 21 of a measuring tube 2 and protruding through a bore 22, a vortex sensor 3. This can be, for example, a dynamically compensated, vortex sensor with a capacitive sensor element, such as is described in U.S. Pat. No. 6,003,384.
Along a diameter of the measuring tube 2 in its interior is arranged a bluff body 4, which is fixedly connected with the measuring tube 2 with the formation of an illustrated, first securement location 41 and a hidden, second securement location 41*. The center of the bore 22 and the center of the securement location 41 lie on an element of the measuring tube 2.
Bluff body 4 has an impingement surface 42, against which, during operation, a medium being measured, e.g. a liquid, gas or vapor, flows. The bluff body 4 has, additionally, two lateral surfaces, of which only one (front) side 43, is visible in FIGS. 2 and 3. Two shedding edges are formed by the impingement surface 42 and the lateral surfaces. Only one, (front) shedding edge 44 can be completely seen in FIG. 2, while a (back) shedding edge 45 is indicated but not shown completely.
The bluff body 4 of FIGS. 2 and 3 has essentially the shape of a right column of triangular cross section. It is possible, however, also to use other usual shapes of bluff body for the invention.
By flow of the medium against the impingement surface 42, a Karman vortex street forms in known manner downstream of the bluff body 4, wherein, at each shedding edge, vortices are alternately shed and entrained, or carried along, by the flowing medium. The vortices produce local pressure fluctuations in the flowing medium, whose time-referenced shedding frequency, thus their so-called vortex frequency, is a measure for the flow velocity and/or the volume flow rate of the medium.
The pressure fluctuations are converted by means of the vortex sensor 3 into a vortex signal serving as an electrical measurement signal, which is fed to a measuring electronics (not shown) accommodated in the electronics housing. The measuring electronics calculates therefrom, for example, the flow velocity and/or the volume flow of the flowing medium.
Vortex sensor 3 is inserted downstream from the bluff body 4 into the bore 22 in the wall 21 of the measuring tube 2 and seals the bore 22 against escape of medium, for which purpose the vortex sensor 3 is screw-connected with the wall 21. Serving for this purpose are e.g. four screws, of which the screws 5, 6, 7 can be seen in FIGS. 2 and 3. The screws engage in corresponding bores 50, 60, 70, 80.
Vortex sensor 3 includes, as shown in FIGS. 2 and 3, a wedge-shaped sensor vane 31, which protrudes through the bore 22 of wall 21 into the interior of the measuring tube 2, and a housing cap 32. The housing cap 32 ends in an extension 322, with the interposition of a thinner-walled intermediate piece 323; compare the mentioned U.S. Pat. No. 6,003,384.
The sensor vane 31 has main surfaces, of which only the main surface 311 is visible in FIGS. 2 and 3. The main surfaces align with the mentioned generatrix, or element, of the measuring tube 2 and form a front edge 313. The sensor vane 31 can also have other suitable spatial shapes; thus, for instance, it can have e.g. two parallel main surfaces, which form two parallel front edges.
The sensor vane 31 is shorter than the diameter of the measuring tube 2; it is furthermore, flexurally stiff and has a blind hole. In order that the blind hole has a sufficient diameter, wall portions extend out of the main surfaces. One of these wall portions, wall portion 315, is indicated in FIG. 2. The blind hole reaches, to the extent possible, to the vicinity of the front edge 313 and has a floor there.
Also belonging to the vortex sensor 3 is a membrane, or diaphragm, covering the bore 22 and having a first surface facing toward the medium and a second surface 332 facing away from the medium. The sensor vane 31 is affixed to the first surface and a physical-to-electrical, sensor element is affixed to the second surface. The sensor vane 31, the membrane, its ring-shaped edge and the part of the sensor element 36 secured to the membrane can, for example, be manufactured from a single piece of material, e.g. metal, especially stainless steel. Sensor element 36 produces the above-mentioned signal, whose frequency is proportional to the volume flow rate of the flowing medium.
In the measuring system of the invention, the measuring tube, especially a straight measuring tube, serving for conveying the medium being measured, has, as shown schematically in FIGS. 4, 5 and 6, a smaller flow cross section A1 than a supply segment 400 of the process line connected to the inlet end of the measuring system. Therefore, the measuring system includes, further, a flow conditioner 300 arranged at the inlet end of the measuring tube and mediating between the measuring tube and the supply segment. Flow conditioner 300 has a lumen, through which medium flows during operation. The lumen tapers in the direction of the measuring tube 2. An inlet end of the flow conditioner facing toward the supply segment of the process line has, in such case, a flow cross section a, which is greater than the flow cross section A1 of the measuring tube, while an outlet end of the flow conditioner facing the measuring tube has a flow cross section, which is smaller than the flow cross section of the inlet end of the flow conditioner. Moreover, the flow conditioner has at least a first inner edge E1 arranged upstream from its outlet end and protruding into the lumen of the flow conditioner, especially extending circumferentially along a directrix of the flow conditioner and/or being circular, as well as at least a second inner edge E2 arranged downstream from the first inner edge E1 and likewise protruding into the lumen of the flow conditioner, especially extending circumferentially along a directrix of the flow conditioner and/or being circular. During operation, medium conveyed in the flow conditioner flows against each of these inner edges.
When medium flows during operation through the flow conditioner, there forms between the first inner edge E1 and the second inner edge E2 an essentially toroidal, first vortex w1, which is, at least in steady state, essentially locationally fixed. Each of the inner edges E1, E2 is, in an embodiment of the invention, so formed and so arranged in the flow conditioner that it lies essentially transversely to a longitudinal axis of the flow conditioner and/or transversely to a longitudinal axis of the measuring tube. Furthermore, each of the inner edges extends circumferentially, especially circularly, and, as a result, closes on itself. In the example of an embodiment shown here, the first inner edge is, moreover, arranged in the vicinity, especially the immediate vicinity, of the inlet end of the flow conditioner. Since especially good results can be achieved with comparatively sharp inner edges, each of the inner edges has in an advantageous embodiment an edge radius smaller than 2 mm, especially smaller than 0.6 mm.
In the configuration of the flow conditioner shown here, there is formed upstream from an impingement surface P situated in an end region of the flow conditioner, especially a circularly circumferential, end region, limited by the first inner edge of the flow conditioner and serving for causing medium impinging thereon to eddy, in addition to the first vortex w1, an essentially toroidal, second vortex w2, which is equally essentially locationally fixed, at least in steady state. In fact, the second vortex w2 forms in such a manner that the principal axes of greatest inertia of the two vortices w1, w2 essentially coincide with one another, at least when they are axially extended. Alternatively or in supplementation, the two vortices w1, w2 are advantageously so developed that the principle axis of greatest inertia of each of the two vortices w1, w2, in each case, essentially coincides with the longitudinal axis of the flow conditioner and/or a longitudinal axis of the measuring tube.
Impingement surface P is so arranged and oriented in the flow conditioner therefore that it extends, at least sectionally, essentially perpendicularly to a longitudinal axis of the flow conditioner and/or that it extends sectionally essentially perpendicularly to a longitudinal axis of the measuring tube. Since especially good results can be achieved with a well-developed impingement surface, such has, in an advantageous embodiment of the invention, in the radial direction a height h2 of at least 1 mm. The impingement surface P can be formed, for example, as an essentially planar, annular surface or even conically, such that it tapers toward the measuring tube and widens toward the process line.
As can be seen in each case in FIGS. 4, 5 and 6, the vortex-producing, first inner edge E1 is formed by intersection of the impingement surface P with a first guide surface GS1 (this being itself likewise limited by the first inner edge E1) extending in the direction of the outlet end of the flow conditioner and serving for supporting and stabilizing the first vortex w1. In the example of an embodiment shown here, the impingement surface P, and, as a result, also the first inner edge E1, are formed in simple manner by keeping the inner diameter of the inlet end of the flow conditioner smaller than the caliber of the supply segment of the process line. In an embodiment of the invention, the first guide surface GS1 is so formed that it, for practical purposes, corresponds to a surface of a segment—here about a 1⁄4 or a 1⁄3 segment—of a toroidal shell or a comparable barrel body. This can be implemented in simple manner by forming the guide surface GS1 at least partially by a furrow or groove, such as, for instance, an annular groove, especially a circular and/or circumferential furrow or groove, formed in the flow conditioner, or an inner cone formed in the flow conditioner. Especially, the guide surface GS1 formed between the two inner edges is, in a further embodiment of the invention, at least sectionally formed essentially strongly concavely with reference to a longitudinal axis of the flow conditioner.
In its further course, the first guide surface GS1 eventually meets, as shown, in each case, schematically in the FIGS. 4, 5 and 6, a second guide surface GS2 of the flow conditioner serving for a guiding medium flowing in the flow conditioner, and this meeting results in the formation of the second inner edge E2. The second guide surface GS2 tapering toward the measuring tube can, for instance as also shown in FIGS. 4 to 6, be essentially conically formed, especially in such a manner that it exhibits, at least sectionally, a convex contour line.
In the measuring system of the invention, the inner edges and the guide surfaces are, additionally, especially so formed and so arranged with respect to one another that an inner wall of the flow conditioner effectively exhibits, on the whole, a largely convex contour. By the, on occasion, provided, impingement surface, the extent of the aforementioned convexity of the contour of the inner wall of the flow conditioner is yet more strongly developed.
During measuring operation in the case of the method of the invention, medium is allowed to flow out of the supply segment and into the flow conditioner. Due to the lesser flow cross section in the direction of the longitudinal axis of the flow conditioner, the medium is accelerated. As the medium flows past the first inner edge E1, at least the first vortex w1 is formed within the medium in the inlet region of the flow conditioner, and, indeed, in such a manner, that a principal axis of greatest inertia of the vortex w1 essentially coincides with the longitudinal axis of the flow conditioner and/or a longitudinal axis of the measuring tube. For medium flowing past the vortex w1, such acts both to narrow cross section further as well as also mediatingly in the direction of the guide surface G and, as a result, stabilizes the flow profile.
Vortex w1 is, in such case, supported by the guide surface GS1 provided between the two inner edges E1, E2 and, by the interaction of such guide surface GS1 and the second inner edge E2, limited in its maximum axial extent and, to such extent, largely defined in shape and size. As a result of this, uncontrolled, equally undesired, divisions and/or detachments of vortex w1 are prevented.
For the case shown here, in which at least one other essentially stationary, especially essentially locationally fixed, toroidal vortex is induced in the inlet region of the flow conditioner, effectively an additional cross sectional narrowing and, as a result, also an increased acceleration of the flow takes place. As a result, a Reynolds number sufficiently high for the desired accuracy of measurement of the measuring system and, associated therewith, a sufficiently high degree of turbulence can be achieved, whereby, in turn, an earlier well estimatable and, consequently, also well reproducible, flow profile can be achieved in the measuring tube connected to the flow conditioner.
Further advantageous embodiments and special developments, especially also dimensioning found to be advantageous for the individual elements of the flow conditioner of the invention, are presented in the following Tables 1, 2 and 3, as well as also in the appended claims, wherein the following holds:

    A1—flow cross section of the measuring tube;
    A2—flow cross section of the supply segment of the process line;
    A2/A1—cross section ratio of the flow cross section A2 of the supply segment of the process line to the flow cross section A1 of the measuring tube;
    a—cross section of the lumen of the flow conditioner bounded by the first inner edge E1;
    a/A1—contraction ratio of the cross section a bounded by the first inner edge to the cross section A1 of the measuring tube;
    A2/A1−a/A1—difference between the cross section ratio A2/A1 and the contraction ratio a/A1;
    a/A2—constriction ratio of the cross section a bounded by the first inner edge E1 to the flow cross section A2 of the supply segment of the process line;
    A2/A1−a/A2—difference between the cross section ratio A2/A1 and the constriction ratio a/A2;
    c—cross section of the lumen of the flow conditioner bounded by the second inner edge E2;
    c/A1—contraction ratio of the cross section c bounded by the second inner edge E2 to the cross section A1 of the measuring tube;
    A2/A1−c/A1—difference between the cross section ratio A2/A1 and the contraction ratio c/A1;
    c/A2—constriction ratio of the cross section c bounded by the second inner edge to the flow cross section A2 of the supply segment of the process line;
    A2/A1−c/A2—difference between the cross section ratio A2/A1 and the constriction ratio c/A2;
    D1—caliber of the measuring tube;
    D2—caliber of the supply segment of the process line connected to the inlet of the measuring system;
    D2/D1—caliber ratio of the caliber D2 of the supply segment of the process line to the caliber D1 of the measuring tube;
    d—diameter of the cross section of the lumen of the flow conditioner bounded by the inner edge E;
    L1—installed length of the measuring tube;
    L2—installed length of the flow conditioner;
    Lm—separation of the sensor element from the inlet end of the measuring tube;
    α—flank angle of an inner cone forming the impingement surface of the flow conditioner (α=90°−α⊥); and
    β—flank angle of an inner cone forming the guide surface of the flow conditioner.


As regards advantageous embodiments and further developments of the flow conditioner, especially also in relation to the measuring tube, as well as suitable dimensions and uses of the measuring system as a whole, reference is additionally made to the disclosure of the non-prepublished, international patent applications PCT/EP2007/057467 and PCT/EP2007/057468, whose content is to be considered as supplementing the disclosure of the present application.

















TABLE 1





D1
D2/D1
d/D1
D2/d
A2/A1
a/A1
a/A2
(A2 − a)/A1
(a − A1)/A2
(A2 − a)/a
(a − A1)/A1







 15 min
1.75
1.58
1.10
3.06
2.51
0.26
0.55
0.16
0.22
1.51


 15 max
3.10
1.58
1.96
9.61
2.51
0.82
7.11
0.49
2.84
1.51


 25 min
1.57
1.23
1.27
2.46
1.52
0.30
0.93
0.10
0.61
0.52


 25 max
2.24
1.23
1.82
5.03
1.52
0.62
3.51
0.21
2.30
0.52


 40 min
1.29
1.18
1.09
1.67
1.40
0.30
0.27
0.08
0.20
0.40


 40 max
2.17
1.18
1.83
4.69
1.40
0.84
3.29
0.24
2.36
0.40


 50 min
1.50
1.15
1.30
2.24
1.32
0.28
0.93
0.07
0.70
0.32


 50 max
2.18
1.15
1.90
4.74
1.32
0.59
3.42
0.14
2.59
0.32


 80 min
1.32
1.18
1.11
1.73
1.39
0.30
0.34
0.08
0.24
0.39


 80 max
2.16
1.18
1.83
4.67
1.39
0.80
3.28
0.23
2.35
0.39


100 min
1.51
1.15
1.31
2.27
1.33
0.29
0.94
0.07
0.71
0.33


100 max
2.14
1.15
1.85
4.57
1.33
0.59
3.23
0.15
2.43
0.33


150 min
1.41
1.39
1.02
1.99
1.92
0.61
0.07
0.29
0.04
0.92


150 max
1.78
1.39
1.28
3.17
1.92
0.96
1.25
0.46
0.65
0.92


200 min
1.32
1.15
1.02
1.73
1.33
0.29
0.07
0.07
0.04
0.33


200 max
2.16
1.39
1.85
4.67
1.92
0.96
3.28
0.46
2.43
0.92


250 min
1.32
1.15
1.02
1.73
1.33
0.29
0.07
0.07
0.04
0.33


250 max
2.16
1.39
1.85
4.67
1.92
0.96
3.28
0.46
2.43
0.92


300 min
1.32
1.15
1.02
1.73
1.33
0.29
0.07
0.07
0.04
0.33


300 max
2.16
1.39
1.85
4.67
1.92
0.96
3.28
0.46
2.43
0.92


350 min
1.32
1.15
1.02
1.73
1.33
0.29
0.07
0.07
0.04
0.33


350 max
2.16
1.39
1.85
4.67
1.92
0.96
3.28
0.46
2.43
0.92


400 min
1.32
1.15
1.02
1.73
1.33
0.29
0.07
0.07
0.04
0.33


400 max
2.16
1.39
1.85
4.67
1.92
0.96
3.28
0.46
2.43
0.92


500 min
1.32
1.15
1.02
1.73
1.33
0.29
0.07
0.07
0.04
0.33


500 max
2.16
1.39
1.85
4.67
1.92
0.96
3.28
0.46
2.43
0.92


600 min
1.32
1.15
1.02
1.73
1.33
0.29
0.07
0.07
0.04
0.33


600 max
2.16
1.39
1.85
4.67
1.92
0.96
3.28
0.46
2.43
0.92



























TABLE 2






(A2/A1) −
(A2/A1) −




(D2/D1) −






D1
(a/A1)
(a/A2)
(D2 − d)/D1
(d − D1)/D2
(D2 − d)/d
(d − D1)//D1
(d/D2)
L1/D2
L1/D1
L2/D2
L2/D1


























 15 min
0.55
2.24
0.17
0.19
0.10
0.58
0.84
3.75
11.62
0.89
2.77


 15 max
7.11
9.35
1.52
0.33
0.96
0.58
2.59
6.64
11.62
1.59
2.77


 25 min
0.93
1.84
0.33
0.10
0.27
0.23
0.78
3.17
7.11
0.50
1.12


 25 max
3.51
4.73
1.01
0.15
0.82
0.23
1.69
4.54
7.11
0.71
1.12


 40 min
0.27
0.83
0.11
0.08
0.09
0.18
0.38
2.03
4.39
0.40
0.86


 40 max
3.29
4.39
0.98
0.14
0.83
0.18
1.62
3.40
4.39
0.67
0.86


 50 min
0.93
1.66
0.35
0.07
0.30
0.15
0.73
2.00
3.36
0.32
0.71


 50 max
3.42
4.46
1.03
0.10
0.90
0.15
1.65
2.24
4.38
0.47
0.71


 80 min
0.34
0.93
0.14
0.08
0.11
0.18
0.42
1.49
2.53
0.40
0.86


 80 max
3.28
4.37
0.98
0.14
0.83
0.18
1.62
1.93
3.21
0.65
0.86


100 min
0.94
1.69
0.35
0.07
0.31
0.15
0.74
1.10
2.36
0.34
0.74


100 max
3.23
4.28
0.98
0.10
0.85
0.15
1.60
1.56
2.36
0.49
0.74


150 min
0.07
1.03
0.03
0.22
0.02
0.39
0.43
0.15
0.22
1.03
1.83


150 max
1.25
2.56
0.39
0.27
0.28
0.39
1.00
0.45
0.76
1.30
1.83


200 min
0.07
0.93
0.03
0.07
0.02
0.15
0.42
0.15
0.22
0.34
0.74


200 max
3.28
4.37
0.98
0.27
0.85
0.39
1.62
1.93
3.21
1.30
1.83


250 min
0.07
0.93
0.03
0.07
0.02
0.15
0.42
0.15
0.22
0.34
0.74


250 max
3.28
4.37
0.98
0.27
0.85
0.39
1.62
1.93
3.21
1.30
1.83


300 min
0.07
0.93
0.03
0.07
0.02
0.15
0.42
0.15
0.22
0.34
0.74


300 max
3.28
4.37
0.98
0.27
0.85
0.39
1.62
1.93
3.21
1.30
1.83


350 min
0.07
0.93
0.03
0.07
0.02
0.15
0.42
0.15
0.22
0.34
0.74


350 max
3.28
4.37
0.98
0.27
0.85
0.39
1.62
1.93
3.21
1.30
1.83


400 min
0.07
0.93
0.03
0.07
0.02
0.15
0.42
0.15
0.22
0.34
0.74


400 max
3.28
4.37
0.98
0.27
0.85
0.39
1.62
1.93
3.21
1.30
1.83


500 min
0.07
0.93
0.03
0.07
0.02
0.15
0.42
0.15
0.22
0.34
0.74


500 max
3.28
4.37
0.98
0.27
0.85
0.39
1.62
1.93
3.21
1.30
1.83


600 min
0.07
0.93
0.03
0.07
0.02
0.15
0.42
0.15
0.22
0.34
0.74


600 max
3.28
4.37
0.98
0.27
0.85
0.39
1.62
1.93
3.21
1.30
1.83






















TABLE 3










(A2/A1) −
(A2/A1) −



D1
(c/A1)
(c/A2)
(c/A2)
(C/A2)









 15 min
1.68
0.17
2.38
0.99



 15 max
2.07
0.68
9.44
7.94



 25 min
0.98
0.19
1.99
1.31



 25 max
1.14
0.47
4.84
4.05



 40 min
0.94
0.20
0.97
0.51



 40 max
1.16
0.69
4.49
3.75



 50 min
0.89
0.19
1.81
1.27



 50 max
0.97
0.43
4.55
3.85



 80 min
0.93
0.20
1.10
0.64



 80 max
1.09
0.63
4.47
3.74



100 min
0.90
0.20
1.83
1.25



100 max
1.02
0.45
4.37
3.67



150 min
1.56
0.49
1.21
0.43



150 max
1.56
0.78
2.68
1.61



200 min
0.90
0.20
1.10
0.43



200 max
1.56
0.78
4.47
3.74



250 min
0.90
0.20
1.10
0.43



250 max
1.56
0.78
4.47
3.74



300 min
0.90
0.20
1.10
0.43



300 max
1.56
0.78
4.47
3.74



350 min
0.90
0.20
1.10
0.43



350 max
1.56
0.78
4.47
3.74



400 min
0.90
0.20
1.10
0.43



400 max
1.56
0.78
4.47
3.74



500 min
0.90
0.20
1.10
0.43



500 max
1.56
0.78
4.47
3.74



600 min
0.90
0.20
1.10
0.43



600 max
1.56
0.78
4.47
3.74










While the invention has been illustrated and described in detail in the drawings and forgoing description, such illustration and description is to be considered as exemplary not restrictive in character, it being understood that only exemplary embodiments have been shown and described and that all changes and modifications that come within the spirit and scope of the invention as described herein are desired to protected.

## Claims

1. A measuring system inserted into the course of a process line for registering at least one measured variable of a medium flowing in the process line, said measuring system comprising:
a circular-cylindrical measuring transducer, including a measuring tube which serves for conveying the medium to be measured and which shows a smaller flow cross section than a supply segment of the process line connected to an inlet of the measuring system;
a sensor arrangement which includes at least one sensor element reacting primarily to said variable to be registered and/or reacting primarily to changes of said variable to be registered, and provides, by means of the at least one sensor element, at least one measurement signal influenced by the measured variable; and
a measuring electronics communicating with the measuring transducer and producing, taking into consideration the at least one measurement signal, at least one measured value instantaneously representing the measured variable; and
a flow conditioner arranged at an inlet of said measuring tube, said flow conditioner mediating between said measuring tube and the supply segment of the process line, said flow conditioner showing a lumen which tapers toward said measuring tube, and through which medium flows during operation, an inlet end of said flow conditioner, facing the supply segment of the process line, shows a flow cross section which is greater than the flow cross section of said measuring tube, and an outlet end of said flow conditioner, facing toward said measuring tube, shows a flow cross section which is smaller than the flow cross section of the inlet end of said flow conditioner, wherein:
said flow conditioner includes, arranged upstream of its outlet end, at least a first inner edge protruding into the lumen of said flow conditioner and against which medium conveyed in said flow conditioner flows during operation;
said flow conditioner also includes, arranged downstream from the first inner edge, at least a second inner edge likewise protruding into the lumen of said flow conditioner and against which medium conveyed in said flow conditioner flows during operation, and said flow conditioner also includes a first guide surface serving to guide medium flowing in said flow conditioner and a second guide surface serving to guide medium flowing in said flow conditioner, said first guide surface extending between the first inner edge and the second inner edge, and said second guide surface extending from the second inner edge in the direction of the outlet end of said flow conditioner, and
said flow conditioner shows an installed length, which is smaller than an installed length of said measuring tube, so that an installed length ratio, defined by a ratio of the installed length of said flow conditioner to the install length of said measuring tube, is kept smaller than one.

2. The measuring system as claimed in claim 1, wherein:
each of the first and second inner edges protruding into the lumen of said flow conditioner has an edge radius smaller than 2 mm; and
a cross section ratio, defined by a ratio of the flow cross section of the supply segment of the process line to the flow cross section of said measuring tube, is kept greater than 1.5 and smaller than 10.

3. The measuring system as claimed in claim 1, wherein:
a cross section of the lumen of said flow conditioner bounded by one of the first and second inner edges is smaller than the flow cross section of the supply segment of the process line.

4. The measuring system as claimed in claim 3, wherein:
a constriction ratio, defined by a ratio of a cross section bounded by the first inner edge to the flow cross section of the supply segment of the process line, is kept smaller than 0.9 and greater than 0.1 and;
a contraction ratio, defined by a ratio of the cross section bounded by the first inner edge to the flow cross section of said measuring tube, is kept greater than 1.2 and smaller than 5.

5. The measuring system as claimed in claim 1, wherein:
a cross section ratio, defined by a ratio of the flow cross section of the supply segment of the process line to the flow cross section of said measuring tube, is kept greater than 1.5 and smaller than 10, and a constriction ratio, defined by a ratio of a cross section bounded by the first inner edge to the flow cross section of the supply segment of the process line, is kept smaller than 0.9 and greater than 0.1; and
a difference between said cross section ratio and said constriction ratio is kept greater than 0.5 and smaller than 10.

6. The measuring system as claimed in claim 1, wherein:
a cross section ratio, defined by a ratio of the flow cross section of the supply segment of the process line to the flow cross section of said measuring tube, is kept greater than 1.5 and smaller than 10 and a contraction ratio, defined by a ratio of the cross section bounded by the first inner edge to the flow cross section of said measuring tube, is kept greater than 1.2 and smaller than 5; and
a difference between said cross section ratio and said contraction ratio is kept greater than 0.2 and smaller than 10.

7. The measuring system as claimed in claim 1, wherein:
the measuring tube shows a smaller caliber than a supply segment of the process line attached to the inlet end of the measuring system, and
the inlet end of said flow conditioner facing the supply segment of the process line shows a caliber greater than a caliber of said measuring tube, and the outlet end of said flow conditioner facing said measuring tube shows a caliber smaller than the caliber of the inlet end of said flow conditioner.

8. The measuring system as claimed in claim 7, wherein:
the first inner edge protruding into the lumen of said flow conditioner is formed by keeping the inner diameter of the inlet end of said flow conditioner smaller than the caliber of the supply segment of the process line; and
a cross section of the lumen of said flow conditioner bounded by the first inner edge protruding into the lumen of said flow conditioner shows a diameter, which is smaller than the caliber of the supply segment of the process line; and
a caliber ratio, defined by a ratio of the caliber of the supply segment of the process line to the caliber of said measuring tube, is kept greater than 1.1 and smaller than 5.

9. The measuring system as claimed in claim 1, wherein:
the at least one sensor element is subjected during operation repeatedly to mechanical deformations influenced by the medium flowing in said measuring tube; and
the at least one sensor element is moved during operation repeatedly relative to a static rest position under the influence of medium flowing in said measuring tube.

10. The measuring system as claimed in claim 1, wherein:
said measuring tube shows a smaller caliber than a supply segment of the process line attached to the inlet end of the measuring system, and wherein a caliber ratio, defined by a ratio of the caliber of the supply segment of the process line to the caliber of said measuring tube, corresponds to at least 10% of said installed length ratio.

11. The measuring system as claimed in claim 1, wherein:
said measuring tube shows a smaller caliber than a supply segment of the process line attached to the inlet end of the measuring system; and
said at least one sensor element is arranged at a distance from the inlet end of said measuring tube in and/or on said measuring tube that a ratio of the distance to the caliber of said measuring measuring tube is kept greater than one.

12. The measuring system as claimed in claim 1, wherein:
the first inner edge of said flow conditioner limits an impingement surface of said flow conditioner arranged in a border region of said flow conditioner.

13. The measuring system as claimed in claim 12, wherein:
the impingement surface shows a height in the radial direction of at least 1 mm; and
the impingement surface is at least sectionally essentially planar.

14. The measuring system as claimed in claim 12, wherein:
the impingement surface is at least sectionally essentially conical; and/or
the impingement surface tapers toward said measuring tube; and/or
the impingement surface widens towards the inlet end of said flow conditioner.

15. The measuring system as claimed in claim 12, wherein:
the impingement surface and the first inner edge are formed at least partially by an inner cone formed into the inlet in said flow conditioner; and
the inner cone forming the impingement surface shows a flank angle greater than 45° and smaller than 90°.

16. The measuring system as claimed in claim 12, wherein:
the impingement surface is formed by a first inner cone formed into the inlet of said flow conditioner and extending toward its inlet end, and the second guide surface is formed by a second inner cone formed into the inlet of said flow conditioner and extending toward its outlet end.

17. The measuring system as claimed in claim 16,
wherein:
the first inner cone forming the impingement surface of said flow conditioner shows a flank angle greater than 45° and smaller than 90°; and
the second inner cone forming the second guide surface of said flow conditioner shows a flank angle greater than 2° and smaller than 45°.

18. The measuring system as claimed in claim 1,
wherein:
the second guide surface of said flow conditioner is formed convexly, at least sectionally, with reference to a longitudinal axis of said flow conditioner; and/or
the second guide surface of said flow conditioner is, at least sectionally, concavely formed; and/or
the second guide surface of said flow conditioner tapers toward said measuring tube; and/or
the second guide surface of said flow conditioner is formed essentially conically.

19. The measuring system as claimed in claim 1, wherein:
the second guide surface and the second inner edge are formed, at least in part, by an inner cone formed in the inlet of said flow conditioner.

20. The measuring system as claimed in claim 19, wherein:
the inner cone forming the second guide surface of said flow conditioner shows a flank angle greater than 2°, and smaller than 45°.

21. The measuring system as claimed in claim 1, wherein:
said at least one sensor element is selected from a group consisting of: a sensor element including at least one piezoelectric element, a sensor element including at least one piezoresistive element, a sensor element including at least one solenoidal coil corresponding with an armature, a sensor element including at least one measuring electrode contacting medium flowing in said measuring tube and sensing electric potentials, a sensor element including at least one measuring capacitor reacting to changes of the measured variable and, a sensor element including at least one electrical resistor.

22. The measuring system as claimed in claim 1, wherein:
the measuring transducer comprises at least one bluff body arranged in said measuring tube, and the at least one sensor element of the sensor arrangement is arranged downstream from the at least one bluff body.

23. The measuring system as claimed in claim 22, wherein:
said at least one sensor element of the sensor arrangement protrudes at least partially into said measuring tube.

24. The measuring system as claimed in claim 1, wherein:
the measuring transducer is selected from a transducer group consisting of: vortex flow transducer, a magneto-inductive flow transducer, a Coriolis mass flow transducer, a density transducer viscosity transducer, and an ultrasonic flow transducer.

25. The measuring system as claimed in claim 1,
wherein:
the measured variable is selected from a group consisting of: a mass flow, a volume flow, a flow velocity, a density, a viscosity, a pressure, and a temperature; and/or
the at least one measured value produced by said measuring electronics is selected from a group consisting of: a mass flow measured value, a volume flow measured value, a density measured value, a viscosity measured value, a pressure measured value, and a temperature measured value.

26. The measuring system as claimed in claim 1, wherein:
a cross section of the lumen of said flow conditioner bounded by the first inner edge protruding into the lumen of said flow conditioner is greater than a cross section of the lumen of said flow conditioner bounded by the second inner edge protruding into the lumen of said flow conditioner;
a cross section of the lumen of said flow conditioner bounded by a second inner edge protruding into the lumen of said flow conditioner is smaller than the flow cross section of the supply segment of the process line,
a constriction ratio, defined by a cross section of the lumen of said flow conditioner bounded by the second inner edge to the flow cross section of the supply segment of the process line, is kept smaller than 0.9 and greater than 0.1, and
a contraction ratio, defined by a ratio of the cross section bounded by the second inner edge to the flow cross section of said measuring tube, is kept greater than 0.9 and smaller than 5.

27. The measuring system as claimed in claim 1, wherein:
a cross section ratio, defined by a ratio of the flow cross section of the supply segment of the process line to the flow cross section of said measuring tube, is kept greater than 1.5 and smaller than 10, a contraction ratio, defined by a ratio of the cross section bounded by the second inner edge to the flow cross section of said measuring tube, is kept greater than 0.9 and smaller than 5; and
a difference between said cross section ratio and said contraction ratio is kept greater than 0.2 and smaller than 10.

28. The measuring system as claimed in claim 1,
wherein:
the first guide surface is essentially strongly concavely formed at least sectionally with respect to a longitudinal axis of said flow conditioner; and/or
the second guide surface is essentially convex.

29. The measuring system as claimed in claim 1,
wherein:
the process line is embodied as a pipeline; and/or
the first guide surface is formed, at least partially, by a furrow formed in said flow conditioner; and/or
the first guide surface is formed by an annular groove formed in said flow conditioner.

30. The use of a measuring system as claimed in claim 1 for registering at least one measured variable, especially a mass flow, a volume flow, a flow velocity, a density, a viscosity, a pressure, a temperature of a medium flowing in the process line.

31. A method for registering at least one measured variable, of a medium flowing in a process line, by means of a measuring system inserted into the course of the process line, said measuring system including a flow conditioner connected to a supply segment of the process line, as well as a measuring transducer connected to the flow conditioner, said method comprising:
allowing medium to be measured to flow out of the supply segment into the flow conditioner:
accelerating the flowing medium in the direction of a longitudinal axis of the flow conditioner;
inducing at least one essentially stationary toroidal vortex within medium flowing in an inlet region of the flow conditioner in a manner such that a principal axis of greatest inertia of the at least one toroidal vortex essentially coincides with the longitudinal axis of the flow conditioner, and/or a longitudinal axis of the measuring tube;
allowing the medium being measured to flow past the at least one toroidal vortex; and
allowing the medium being measured to flow out of the flow conditioner into a measuring tube of the connected measuring transducer, as well as producing at least one measurement signal influenced by the measured variable to be registered, by application of at least one sensor element reacting primarily to the measured variable, especially also to changes in the same,
wherein the step of inducing the at least one, essentially stationary, toroidal vortex in the inlet region of the flow conditioner includes steps of:
allowing medium to flow past a first inner edge of the flow conditioner protruding into a lumen of the flow conditioner as well as allowing medium to flow past a second inner edge of the flow conditioner located downstream from the first inner edge and protruding into a lumen of the flow conditioner.

32. The method as claimed in claim 31, further comprising:
inducing at least one further, essentially stationary, toroidal vortex in the inlet region of the flow conditioner in such a manner that a principal axis of greatest inertia of each of the at least two toroidal vortices extends essentially parallel with one another and, at least when imaginary axially extended, essentially coincides with the other.

33. The method as claimed in claim 32, further comprising:
allowing medium to flow against an impingement surface of the flow conditioner opposing flowing medium in a boundary region of the flow conditioner, for inducing essentially stationary, toroidal vortices in the inlet region of the flow conditioner.