DE202017006709U1 - Coriolis mass flowmeter - Google Patents

Abstract

Coriolis mass flowmeter comprising - a housing body (10) having a flow inlet (31) and a flow outlet (32) for a fluid medium, - two spaced apart measuring tubes (23, 24) which are fixed to the housing body (10) and the flow inlet (31) and the flow outlet (32) connect to each other, - at least one electrically controllable vibration exciter (42, 45) for each measuring tube (23, 24), wherein the vibration generator (42, 45) is adapted to the measuring tube ( 23, 24) and at least two electrically controllable vibration sensors (41, 43, 44, 46), wherein the vibration sensors (41, 43, 44, 46) are adapted to control the vibration of at least one of the two measuring tubes (23 , 24), characterized in that the vibration exciter (42, 45) and the vibration sensor (41, 43, 44, 46) fixed space between the two measuring tubes (23, 24) on the housing body (1 0).

Description

The invention relates to a Coriolis mass flowmeter having a housing body having a flow inlet and a fluid medium flow outlet, and having two spaced apart, preferably parallel, measuring tubes fixed to the housing body and interconnecting the flow inlet and the flow outlet. such that a fluid medium to be measured flows from the flow inlet through the measuring tube to the flow outlet, ie in other words, that the measuring tubes fluidly connect the flow inlet and the flow outlet. For each measuring tube at least one electrically controllable vibration exciter is provided, wherein the vibration exciter is adapted to set the measuring tube in vibration. Furthermore, the Coriolis mass flowmeter has at least two electrically controllable vibration sensors, wherein the vibration sensors are adapted to receive the vibration of at least one of the two measuring tubes. When measuring the flow of the fluid medium, the two measuring tubes oscillate against each other.

The principle of Coriolis mass flow meters is known from the prior art and is, for example, in the US 6,776,052 B2 or the EP 1 429 119 A1 described. The principle of the known Coriolis mass flow meters is described below with reference to 1 described in perspective a Coriolis mass flowmeter 100 ' according to the prior art shows. In order to allow an inside view, parts of the housing and process connections are not displayed. Connection cable and evaluation electronics are in 1 also not shown. The connection cables usually run freely between the electronic components and a device plug for connecting a device-external measuring and evaluation electronics or to a measuring and evaluation electronics arranged outside the measuring space.

Coriolis mass flowmeter 100 ' in the prior art have two measuring tubes 1' . 2 ' and a vibration exciter consisting of a permanent magnet coil pair 9 ' . 10 ' is built to vibrations on the measuring tubes 1' . 2 ' transferred to. Furthermore, two vibration sensors are provided, which each also consist of a permanent magnet coil pair 11 ' . 13 ' respectively. 12 ' . 14 ' for absorbing the vibrations of the measuring tubes 1' . 2 ' are constructed. The permanent magnet coil pair 9 ' and 10 ' . 11 ' and 13 ' . 12 ' and 14 ' are each such on the measuring tubes 1' . 2 ' arranged that the permanent magnets 9 ' . 11 ' . 12 ' on the measuring tube 1' and the coils 10 ' . 13 ' and 14 ' on the measuring tube 2 ' are determined by suitable holder. When a current pulse through the coil 10 ' of the vibration exciter on the measuring tube 2 ' flows, which is on the other measuring tube 1' fixed permanent magnet 9 ' (still polarity) in the coil 10 ' pulled in or from the coil 10 ' repelled. This will cause the two measuring tubes 1' and 2 ' vibrating against each other.

For fixing the measuring tubes 1' . 2 ' are at least two coupling elements 3 ' . 4 ' , sometimes called crossbars or gusset plates, designed to couple the measuring tubes to the vibration conditions for both tubes 1' and 2 ' comparable to keep. The inlet and outlet sides of the two measuring tubes 1' . 2 ' are in pairs, each with a flow divider 5 ' . 6 ' connected, of which the flow divider 5 ' on the inlet side, the flowing fluid to the inlets of the two measuring tubes 1' . 2 ' feeds and the flow divider 6 ' at the outlet side discharges the flowing fluid from the outlets of the two measuring tubes. The flow dividers 5 ' . 6 ' are inlet and outlet side of a (only partially illustrated, inside hollow) housing 7 ' recorded so that the measuring tubes 1' . 2 ' , the vibrational exciter 9 ' . 10 ' , the vibration sensor 11 ' . 13 ' such as 12 ' . 14 ' and the coupling elements 3 ' . 4 ' inside the case 7 are protected. The housing 7 is also constructed so that the implementation 8th' of cables from the inside of the device to the outside, ie to the measuring and evaluation electronics, is possible.

To be installed in a process line, Coriolis mass flow meters also include process connections (in 1 not shown), the inlet and outlet side depending on the housing variant either with the housing 7 ' or directly with the flow dividers 5 ' . 6 ' are connected.

In Coriolis mass flow meters according to the prior art vibration exciters are usually constructed such that they, for example, a permanent magnet 9 ' on one of the measuring tubes 2 ' as well as a coil 10 ' on the opposite measuring tube 1' to electrically impart vibrations to both of the measuring tubes by generating a force effect 1' . 2 ' transferred to. Each of the two vibration sensors usually also has one permanent magnet each 11 ' . 12 ' on one of the measuring tubes 1' as well as one coil each 13 ' . 14 ' on the opposite measuring tube 2 ' on to the vibrations of the measuring tubes 1' . 2 ' to detect by induction effect. The vibration sensors are usually mounted on the inlet and outlet side.

The US 5,349,872 describes an arrangement of excitation and measuring coils on boards, which are respectively arranged above and below the measuring tubes and fixed by means of angles to a housing shell.

Without flow, the signals of the two vibration sensors are in phase with each other. When flowing fluid (fluid medium) results from the inlet and outlet side different Coriolis forces a phase shift of the signals of the two vibration sensor, which is proportional to the instantaneous mass flow of the fluid medium. The mass flow of the fluid medium can be determined by the phase shift of the signals.

Coriolis mass flowmeters 100 ' According to the state of the art, there are many different measuring ranges. The spectrum ranges from very large devices with a mass flow of thousands of tons per hour down to very small devices with a mass flow of one kilogram per hour and less. The smaller but a Coriolis mass flowmeter 100 ' According to the state of the art, the more constructive and ultimately metrological problems crop up, because while most components of the device when zooming out of the meter 100 ' (according to the measuring range) can also be well downsized, such as the measuring tubes 1' . 2 ' , the magnets 9 ' . 11 ' . 12 ' , the coupling elements 3 ' . 4 ' etc. and even the case 7 ' so is a scaling up to small sizes for the coils 10 ' . 13 ' . 14 ' the vibration exciter and vibration sensor and, accordingly, for their fastening elements on the measuring tubes 1' . 2 ' , the so-called coil holder, not so easy. Both bring with small Coriolis mass flow meters according to the prior art various unfavorable measurement characteristics of these devices with it and leads to design difficulties.

It is therefore an object of the present invention to provide a Coriolis mass flowmeter that is structurally simpler and more scalable to small sizes (for a correspondingly small measurement range).

This object is achieved by a Coriolis mass flowmeter with the features of claim 1. For this purpose, it is provided in particular in a Coriolis mass flowmeter of the type mentioned at the outset that the vibration exciters and the vibration transducers are fixed in space to the housing body, for example to a construction of the housing body, between the two measuring tubes. In the sense of the Coriolis mass flowmeter according to the invention described below, oscillation exciters and oscillating transducers are understood as meaning the electrically controllable components of the oscillation exciters and oscillating transducers, for example electromagnetically operated coils.

By fixed to the housing body in a space-tight manner, it is meant that the vibration exciters and vibration sensors are not attached to a component vibrated relative to the housing body for carrying out the measurement, i. In particular, not on a measuring tube, are fixed and are relative to the housing body with vibrated. By this is meant that vibration exciters and vibration sensors are not fixed to a component that is vibrated according to the applied measuring principle and whose vibration is detected and evaluated for determining the mass flow of the medium. Possible due to the construction inherent vibrations of vibration exciters, vibration or Ankonstruktion, compared to the metrologically required vibration of the measuring tubes are small (eg. Less than 10% or 20%) are not referred to as oscillations in the sense of this description and are considered space considered. Such possible vibrations are undesirable, and it is also an aspect of the invention to avoid such unwanted vibrations. The concept proposed according to the invention also contributes to this, that the electrically controllable parts of the vibration exciters and oscillating transducers do not react on parts which resonate in accordance with the intended purpose, i. in particular not on the measuring tubes, are arranged.

Because the electrically controllable vibration exciters and vibration sensors are not attached to the measuring tubes and not resonate with them in the implementation of the measuring principle, the electrically controllable vibration exciters and vibration sensors do not affect the vibration of the measuring tubes, and thus the measurement itself.

Consider, for example, the outer dimensions of the coils as vibration exciters and vibration transducers which, according to the design principle known from the prior art, would have to be very small if they were to be fixed on correspondingly small measuring tubes. The diameter of the coil wire would then be so thin that it could hardly be wound and that sudden wire breaks on the connecting wires connecting the coil to the continuity lines inside the device could or would occur. Such wire breaks are always, even with very large devices, on the agenda, because in Coriolis mass flow meters according to the prior art, the connecting wires swing together with the coils, more or less uncontrolled, always with what even with meters in accordance with large dimensions leads to problems and for small measuring devices in a correspondingly small measuring range is no longer manageable.

However, the fact that coils, coil wire, and coil holders can not be arbitrarily reduced adds to the problems associated with prior art small Coriolis mass flow meters. From a certain size, coils and coil holding become very heavy as compared to the measuring tubes themselves. Due to the relatively high mass of the coils and the coil holder, the natural frequency of the measuring tubes changes gravely downwards. The devices then operate in areas of very low frequencies, e.g. near 100 hearts or even lower, which not only makes the devices less accurate, but also very sensitive to external influences such as Vibrations, shockwaves u. a. makes. Furthermore, due to the local increase of the mass through the coils and the coil holders, there are very high mass jumps in the system "measuring tube-fluid-coil-coil holder", so that during the operation, various self-dynamics modes occur which falsify the measurement result even further.

Also, small scale Coriolis mass flowmeters of the prior art are experiencing another problem due to downsizing. Dimensional deviations and tolerances in the production and assembly of the ever smaller components are beginning to become even more important than with large (large-scale) measuring instruments. The concatenation of dimensional deviations and tolerances is also particularly important with small measuring instruments. As a result, small devices are in most cases more difficult to manufacture and usually less accurate than larger devices.

These disadvantages described above are inventively avoided in that just the electrically controllable parts that can not be simply scaled arbitrarily small due to the function and also need an electrical connection to the measurement and evaluation, are no longer part of the oscillating system. This reduces the mechanical stresses (eg concerning the cable connection) and the influence on the measuring system (i.e. the oscillating measuring tubes).

The vibration exciters are preferably arranged between the measuring tubes in such a way that the vibration exciters for the one and the other measuring tubes act on the measuring tubes in opposite spatial directions during the electrical activation. This has the consequence that in the same and simultaneous electrical control of the vibration exciter, the measuring tubes are vibrated in opposite directions, so that with flowing fluid medium, by the phase shift of the signals due to the Coriolis effect, the flow of the fluid medium in the mass flow meter can be measured ,

As vibration exciter and vibrating transducer electromagnetic coils can be used according to the invention, for example, can be identical for all vibration exciters and vibration sensor. Each electromagnetic coil may cooperate with a permanent magnet attached to one of the measuring tubes for generating the oscillation or for absorbing the oscillation. In the electrical control of acting as a vibration exciter coil this is energized, generates a magnetic field and thereby moves the fixed to the measuring tube permanent magnet. By a correspondingly set admission with current so a vibration of the measuring tube can be generated. Conversely, caused by the vibration of the measuring tube movement of the permanent magnet in the coil causes a current that can be measured in the context of electrical control of the acting as a vibration coil coil, for example. By a current and / or voltage measurement. The use of substantially identical or completely identical coils has the advantage that the vibration generation and vibration absorption are easily matched. The permanent magnets on the measuring tubes can easily scale in accordance with the size and mass of the measuring arrangement, and in particular of the measuring tubes and mechanically (unlike, for example, used for controlling electrical components connecting cable) in the vibration of the measuring tubes relative to them (ie the permanent magnets ) carrying measuring tubes.

According to a preferred embodiment may be attached to the housing body a Ankonstruktion (in the sense of a holder), which carries the vibration exciter and vibrating transducer (so that the vibration exciter and vibrating transducer are fixed to the Ankonstruktion and are arranged between the measuring tubes). The Ankonstruktion can be formed by stable components, eg. According to massive and non-flexible fasteners (such as angle, columns, guides, board holder, non-flexible board) so that it intercepts the resulting in the generation of vibration of the measuring tubes opposing forces and the vibration exciters and vibration sensor fixed in space to the housing body and their (unwanted) possible inherent vibration attenuates or absorbs. The Ankonstruktion is designed so that the vibration exciter and vibrating transducer are arranged in the manner described in this invention between the two measuring tubes.

In a preferred development of the invention, the attachment can have at least one printed circuit board on which the electrically activatable vibration exciters and vibration pickups are fixed and can be controlled via printed conductors formed on the printed circuit board. Thus, the entire control of the sensor components and possibly also provided there measuring electronics can be done via the board. Thus, according to the invention, there are no wire connections or other electrical connections to the vibration exciters and vibration transducers, in particular the coils, or other electrical or electronic components of the measuring device (measuring electronics) which are mechanically stressed by the vibrations, and with the excited oscillation of the measuring tubes for example, can break. The measuring electronics on the board can also comprise other electrical and / or electronic components, such as eg processor, sensor (for example a temperature sensor and / or other sensors), evaluation electronics or the like and can be integrated in an electrical circuit, without having to do so Measuring range between the measuring tubes must be made a wiring that may affect the measurement. This arrangement also makes it possible to attach any electronically or electrically controllable components to the measuring tubes themselves and thus to influence their natural frequency in the oscillation and thereby distort measurement results or provide appropriate corrections. The permanent magnets, or possibly instead of the permanent magnets provided on measuring tubes balance weights, can be the same everywhere, so that no change in the vibration characteristics of one is generated relative to the other measuring tube. In addition, the permanent magnets can also scale with the measuring tubes so that the weight of the permanent magnets does not cause local changes in the oscillating angles, for example local higher-order vibrations.

According to a preferred embodiment, exactly two vibration transducers are arranged on at least one measuring tube, wherein at least one vibration exciter is provided on a measuring tube. Furthermore, according to a preferred simple embodiment, precisely one vibration exciter can be provided on each measuring tube, although embodiments may also be expedient in which exactly two or more vibration sensors and / or vibration exciters are assigned to a measuring tube.

In a one-sided phase measurement (ie, an oscillation on only one measuring tube), the Coriolis mass flow meter so that a total of two vibration exciters (one per measuring tube) and two oscillating transducer on one of the two measuring tubes have, where vibration sensor for the other measuring tube are mounted, if necessary are not addressed or are approachable. If only one-sided phase measurement is provided on a measuring tube, it is also possible for balancing weights to be arranged on the other measuring tube instead of the permanent magnets, preferably with the same weight as the permanent magnets and at the same positions.

In a two-sided phase measurement (i.e., a vibration pick-up on each meter tube), the Coriolis mass flow meter can use a total of two vibrators (one per meter tube) and four vibrating pickups, i. two on each of the two measuring tubes.

According to a preferred embodiment, the vibration exciter can be arranged on the (each) measuring tube in the middle between the ends of the measuring tube, wherein the term "on the measuring tube" refers to the position, but not on the type of attachment, which according to the invention yes straight takes place on the base body and not on the measuring tube. This also applies to the vibration sensor. The ends of the measuring tube are those points on both sides of the measuring tube to which the measuring tube is fixed to the housing body. By arranging the vibration exciter in the middle between these points, it is possible with the least possible force to excite a symmetrical oscillation of the measuring tube relative to the dimensions of the measuring tube.

According to the invention, a vibration sensor may be arranged on the measuring tube between one end of the measuring tube and the vibration generator and another vibration sensor may be arranged on the same measuring tube between the other end of the measuring tube and the vibration generator. Basically, the phase shift is greatest between two points that are symmetrical about the center of the measuring tube, but somewhere between the inlet and the center or outlet and center. An often preferred arrangement may be about mid-way between the vibrator and the end of the measuring tube, where about the center may include, for example, an array around the center having a range of variation about the true center of about 25%. A preferred arrangement, for example, may be between about 10% and 15% from the actual center, towards the vibration exciter. However, the arrangement is also dependent on the type and shape of the measuring tubes and can be suitably selected by the skilled person.

According to one embodiment, the measuring tubes can be arranged to run in parallel and the permanent magnets on the measuring tubes to each other be attached opposite and aligned so that attract or repel the permanent magnets.

A particularly suitable shape of the measuring tubes is bent because, due to the curved guidance of the fluid medium, the effect of the acting Coriolis force may possibly be relatively small in comparison to other embodiments, but results in a higher natural frequency of the measuring tubes. The more precise mechanical behavior of the measuring tubes also brings metrological advantages. For example, the measuring tubes may be substantially U-shaped, wherein the outgoing legs of the "u", with which the measuring tube are fixed to the base body, may be shorter or longer than in a letter custom "u". A U-shape with a shortened leg compared to a letter "u" leg is here a preferred embodiment.

A particularly preferred embodiment according to the invention provides that the housing body of the Coriolis mass flowmeter is formed as a solid block of material, preferably as a solid one-piece block of material, in each of which an opening is inserted as a flow inlet and as a flow outlet on opposite end faces, wherein in each case two flow channels each opening lead to an exit in a side surface of the housing body and wherein the outlet of one of the flow channels opens into the one measuring tube and the outlet of the other of the flow channels opens into the other measuring tube. In such an embodiment, the flow channels form flow dividers, to which the measuring tubes are connected. A solid body according to the invention has the advantage of a high mass compared to the vibrating measuring tubes, thereby minimizing unwanted natural oscillations of the measuring device or its components (not the measuring tubes).

Instead of a solid housing body according to the particularly preferred embodiment described above may be provided according to the invention as a flow inlet and flow outlet in each case - from the prior art already known - flow divider on which the measuring tubes are fixed. Even so, a comparable vibration behavior of the measuring tubes can be achieved.

In addition, independently of the provision of a flow divider, the measuring tubes (also in the case of the preferably proposed massive block of material) can be connected to one another by coupling elements, for example in the form of transverse struts or knops. This also promotes a comparable vibration behavior of the measuring tubes.

However, an advantage of the invention preferably proposed solid block of material as the housing body is also in that all of these aforementioned additional elements (separate flow divider, coupling elements) can be dispensed with, because in the continuation of this inventive concept, the ends of the measuring tube fixed directly to the solid housing body may be, and preferably such that an outlet of a flow channel and an opening at the end of a measuring tube lie on one another. The outputs of the flow channels and the openings of the measuring tubes are preferably the same size in order to achieve a uniform flow behavior of the fluid medium at the transition between the flow channel and the measuring tube. In this case, a measuring tube in each case connects the outlet of a flow channel of the flow inlet and the outlet of a flow channel of the flow outlet of the Coriolis mass flowmeter.

A structurally simple and inexpensive attachment of the measuring tubes provides that the ends of the (each) measuring tube to the housing body (or equivalent to the flow divider of the housing body, if no solid housing body is provided) are welded, wherein on the housing body (or equivalent to the flow divider of the housing body) additional material for the formation of the weld is provided, wherein the additional material is formed in particular by the material of the Grundköpers. In a normal weld, welding is done with a wire applied to the weld area from outside. This can be very complicated and technically difficult with a thin weld. According to the invention, the additional material for the formation of the weld can be made available by milling into the solid housing body (material block) a round channel (in the sense of a groove) which forms an annular collar around the flow channel in the middle. This annular collar is then the additional material that is used instead of the welding wire to form the weld between the measuring tube and the body formed by the solid block of material. Because according to the invention can be dispensed with the additional welding wire, the welding of the measuring tube is considerably simplified with the body.

In the solid housing body, a grommet may be formed between the opening of the flow inlet and the opening of the flow outlet extending from the side surface having the outputs of the flow channels to the opposite side surface. Through this cable bushing cables from the board, on which the vibration exciters and the vibration sensor electrically controlled are routed to a device port. The device connection may, for example, also be a connector received in the cable feedthrough. It is also possible, by the cable guide a wired connection to components of the measuring electronics, eg. A control processor or control computer (inside or outside of the meter) to produce.

According to a preferred embodiment, it can also be provided that components of the measuring electronics, for example a control processor, control electronics, evaluation electronics, sensors, such as, for example, temperature sensors, are arranged on the board. The measuring electronics are also referred to in the art as transducers, in the sense of measuring electronics, which controls, measures, converts and / or communicates. Integration of measuring electronics on the board results in a particularly compact design of the Coriolis mass flowmeter, in which all or part of the measuring electronics can be integrated directly into the flowmeter. By the cable bushing and / or arranged on the board itself electrical or electronic components of the measuring electronics loose cable connections are avoided in the measuring chamber of the flowmeter, which could affect the measurements or could be damaged due to the vibrations excited in the measuring space.

Further features, advantages and possible applications of the invention will become apparent from the embodiment of the invention described below with reference to the drawings. All described or illustrated features alone or in any combination form the subject matter of the present invention, also independent of their summary in the claims or their back references.

Show it:

1 in perspective, a Coriolis mass flowmeter according to the prior art;

2 in perspective, a Coriolis mass flow meter according to an embodiment of the invention;

3 a top view of the Coriolis mass flowmeter according to 2 ;

4 in perspective, the Coriolis mass flowmeter according to 2 without vibration exciter, vibration sensor and attachment;

5 in perspective, the vibration exciters, vibration and parts of the construction of the Coriolis mass flowmeter according to 2 ;

6 a side view of the Coriolis mass flowmeter according to 2 ;

6a a cross section through the Coriolis mass flow meter along section AA according to 2 ;

6b a cross section through the Coriolis mass flow meter along section BB according to 2 ;

7 a longitudinal section through the center of the Coriolis mass flowmeter according to 2 ;

8th in perspective, the Coriolis mass flowmeter according to 4 without vibration exciter, vibration sensor and attachment with a detailed representation for fixing the measuring tubes; and

9 in perspective, the Coriolis mass flowmeter according to 2 with mounted housing cover.

2 shows in perspective a Coriolis mass flowmeter 100 according to a preferred embodiment of the present invention without the (in 9 with illustrated) housing cover 30 , On a housing body 10 that has a flow inlet 31 and a flow outlet 32 for a fluid medium, are spaced apart from each other and parallel two measuring tubes 23 . 24 arranged on the housing body 10 are fixed and respectively the flow inlet 31 and the flow outlet 32 connect with each other.

For the first measuring tube 23 is as electrically controllable vibration exciter 42 an electromagnetic coil 2 , and for the second measuring tube 24 is as electrically controllable vibration exciter 45 an electromagnetic coil 5 intended. Each of the vibration exciters 42 . 45 is set up in the associated measuring tube 23 . 24 to vibrate, in front of which he is placed.

Furthermore, in the illustrated embodiment, for each measuring tube 23 . 24 two electrically controllable vibration sensor each 41 . 43 (in 3 visible, in 2 obscured), 44 . 46 provided, wherein the vibration sensor 41 . 43 . 44 . 46 are adapted to the vibration of at least one of the two measuring tubes 23 . 24 take. The vibration sensors 41 . 43 . 44 . 46 are each as electromagnetic coils 1 . 3 (in 3 visible, in 2 obscured), 4 . 6 educated.

As you can see immediately, the coils are 1 . 2 . 3 . 4 . 5 . 6 not on the measuring tubes 23 . 24 itself, but on a reconstruction 7 attached, between the two measuring tubes 23 . 24 is arranged and via fasteners 8th . 9 the construction 7 fixed to a part of the housing, ie, fixed in space with the housing body 10 , connected is. In the illustrated embodiment, the Ankonstruktion includes 7 a circuit board 33 with printed thereon electrical wires (not shown), with the coils 1 . 2 . 3 . 4 . 5 . 6 (ie in other words the vibration exciters 42 . 44 and transducers 41 . 43 . 44 . 46 ; these terms are used interchangeably with coil in the description of the embodiments) and, for example, with continuing lines (also not shown) in the interior of the measuring device 100 or external connections are connected or connectable.

In this embodiment, the coils 1 . 2 . 3 . 4 . 5 . 6 on the board 33 soldered. However, the invention also includes other embodiments in which the coils 1 . 2 . 3 . 4 . 5 . 6 screwed, glued or with other connection techniques on the board 33 or other elements of the constructions 7 are attached.

3 shows the Coriolis mass flowmeter 100 from above, so that too the vibration sensor 43 (Kitchen sink 3 ) is visible.

4 shows the same Coriolis mass flowmeter 100 without the construction 7 with the board 7 and the fasteners 8th . 9 so permanent magnets 11 . 12 . 13 . 14 . 15 . 16 and the magnet holders 17 . 18 . 19 . 20 . 21 . 22 become more visible according to the position of the coils 1 . 2 . 3 . 4 . 5 . 6 on the measuring tubes 23 . 24 are set to be magnetic with the coils 1 . 2 . 3 . 4 . 5 . 6 to interact when the coils 2 . 5 be energized (acted upon) (vibration exciter 42 . 45 ) or in the coils 1 . 3 . 4 . 6 by a movement of the permanent magnets 11 . 13 . 14 . 16 induced voltage or an induced current is measured (vibration sensor 41 . 43 . 44 . 46 ).

At the measuring tubes 23 . 24 this version is two short U-tubes (U-shaped bent tubes). Coupling elements for coupling the loops are not used in this embodiment. However, the invention also includes other embodiments as well, with measuring tubes 23 . 24 are executed in other form and / or where the measuring tubes 23 . 24 together with coupling elements (similar to the illustration in FIG 1 to the prior art) coupled or connected to each other.

5 For the sake of clarity, only the board is shown 33 the construction 7 with the fixed, not movable, ie spatially fixed, coils 1 . 2 . 3 . 4 . 5 . 6 where the coil 3 is not visible and the traces on the board 33 are not shown.

In 6 is a side view of the Coriolis mass flowmeter 100 shown in the behind of the housing body 10 extending measuring tube 24 the construction 7 with the through the fastener 9 by screwing on the housing body 10 held board 33 is visible. On the board 33 are the coils 4 . 5 . 6 each right in front of the measuring tube 24 set, in such a way that in the magnetic holders 20 . 21 . 22 on the measuring tube 24 held, in 6 invisible permanent magnet 14 . 15 . 16 straight into the windings of the coils 4 . 5 . 6 plunge.

This is also illustrated by the cross section 6a along the line AA according to 6 that's on the board 33 in front of the measuring tubes 23 respectively 24 spatially mounted coils 1 . 2 respectively 4 . 5 with the respective magnetic holders 17 . 18 respectively 20 . 21 shows. The permanent magnets 11 . 12 . 14 . 15 are each in the windings of the coils 1 . 2 . 4 . 5 immersed and not visible. The cross section after 6b along the line BB according to 6 also shows, inter alia, a section through the coils 2 . 5 and the magnets 12 . 15 the vibration exciter 42 . 45 ,

7 shows a longitudinal section through the center of the Coriolis mass flowmeter 100 , At the longitudinal section in 7 and at the intersection "AA" in 6 it can be seen that the illustrated embodiment without Coriolis mass flow meters 100 ' According to the prior art customary separate flow divider (see. 1 - 5 ' . 6 ' ) at the flow inlet 31 and flow outlet 32 gets along, because the division of the flow of the fluid medium at the flow inlet 31 on the two measuring tubes 23 . 24 and the merging of these at the flow outlet 32 takes place in the illustrated embodiment directly in the opening 25 of the flow inlet 31 and in the opening 26 the flow outlet 32 , that is, in the massively formed housing body 10 through flow channels 34 . 35 coming from a side surface of the case body 10 in the openings 25 . 26 lead (see also 6a ). However, the invention also includes other embodiments, which differ in terms of flow divider from the embodiment shown here. Also has the meter 100 in the illustrated embodiment, no preferred flow direction, ie flow inlet 31 and flow outlet 32 can also be exchanged. However, the invention also includes other embodiments as well, in which flow inlet 31 and flow outlet 32 may be different for the purpose of flow optimization, and thus the flow direction is predetermined.

Furthermore, the in 7 illustrated embodiment inlet and outlet side via threaded connections 27 . 28 to which process connections can be bolted. However, the invention also includes other embodiments as well, eg completely without process connections, ie with direct connection to the process line or with welded or otherwise (by other connection techniques) connected process connections.

7 also shows a possible design for a cable feedthrough 29 for passing cables from inside the Coriolis mass flowmeter 100 to the outside, eg to a measuring electronics, to the power supply, to the signal forwarding in cases, in which the measuring electronics are inside the device, eg on the board 33 with integrated. However, the invention also includes other embodiments in which the passage of cables takes place elsewhere and in other directions.

8th shows details of the connection of the measuring tubes 23 . 24 with the massive case body 10 , In the illustrated embodiment, the measuring tubes 23 . 24 with the housing body 10 without externally added filler welded. The additional material required to form a particularly durable welded joint, usually a welding wire, becomes part of this design 36 of the housing body 10 through a special education in this area (enlargement in 8th ) provided. Concrete is as part 36 a collar 37 provided in the massive housing body 10 (Material block) as the edge of a round channel 38 (in the sense of a groove) is milled or is. In the middle of the annular collar 38 is the flow channel 34 . 35 educated. This annular collar 38 then forms that into the main body 10 integrated filler, which is used instead of the externally applied welding wire to the weld between the measuring tube 23 . 24 and the body formed by the solid block of material 10 train. However, the invention also includes other embodiments of connection, for example by welding with additional material, by soldering, by gluing or by other joining techniques.

9 shows in perspective a Coriolis mass flowmeter 100 according to embodiment of the present invention with housing cover 30 , It can be seen that the housing in the illustrated embodiment, apart from an intermediate gasket (not shown) consists of only two parts bolted together, the housing body 10 with the components described above and the measuring range of the housing body 10 covering and protective housing cover 30 , However, the invention also includes other embodiments as well, in which, for example, the housing body 10 and the housing cover 30 welded together or otherwise connected together.

The housing body 10 is solid and has the appearance of a simple block in the embodiment shown here. However, the invention also includes other embodiments in which the external appearance is not a block, for example around the board 33 (or other construction 7 ) by a special shape of the housing body 10 directly (ie without the fasteners 8th . 9 ) on the housing body 10 to attach or other special shapes, such as the Coriolis mass flowmeter 100 to attach to a stand or to a wall mount.

While a housing consisting of only two parts (apart from an intermediate seal) has various advantages, the invention also includes other embodiments which provide a housing consisting of more than two parts.

For a Coriolis mass flowmeter 100 according to the present invention, wherein the coils 1 . 2 . 3 . 4 . 5 . 6 no longer on one of the measuring tubes 23 . 24 , but spatially fixed to the housing body 10 (eg a construction 7 or a circuit board 33 the construction 7 ) are also required for a small or very small Coriolis mass flowmeter 100 these coils are not reduced to hard-to-handle dimensions. In most cases, even commercially available coils can be used. There are thus no exotic manufacturing processes for coils and their attachment to the measuring tubes, and no other exotic vibration exciter and Schwingungsaufnehmer principles necessary. These are small and very small Coriolis mass flowmeters 100 according to the present invention more accurate, reliable and economical to manufacture than those of the prior art.

Coriolis mass flowmeters 100 However, according to the present invention are also for even a further reason more reliable than those of the prior art: Because the electrically controllable coils 1 . 2 . 3 . 4 . 5 . 6 (or general vibration exciter 42 . 45 and transducers 41 . 43 . 44 . 46 ) fixed in space relative to the housing body 10 are fixed, there are no oscillating connecting wires from the coils 1 . 2 . 3 . 4 . 5 . 6 or other electrically controllable electrical or electronic components to further lines, and if there are no oscillating connecting wires, then they do not break. Connecting wires can not be made arbitrarily thick, because even with a very low stiffness connecting wires affect the natural frequency of the respective measuring tube noticeably and lead to distortions in the measurement. The lack of such connecting wires according to the invention therefore already leads on its own to qualitatively better measuring results.

For a Coriolis mass flowmeter 100 according to the present invention carry the measuring tubes 23 . 24 only the permanent magnets 11 . 12 . 13 . 14 . 15 . 16 and their associated magnetic holder 17 . 18 . 19 . 20 . 21 . 22 , This results in small and very small mass flowmeters 100 a very light system "measuring tube fluid permanent magnet magnet holder", such as out 4 becomes immediately apparent. This system "measuring tube fluid permanent magnet magnet holder" points beyond that on the measuring tubes 23 . 24 missing coils 1 . 2 . 3 . 4 . 5 . 6 with the associated coil mounts also hardly local mass jumps on, by the comparatively heavy coil technology in the art again and again, and even with larger meters, occur. This is indicated by a Coriolis mass flowmeter according to the invention 100 a simpler, calculable momentum on. Due to the missing coils 1 . 2 . 3 . 4 . 5 . 6 and coil holders on the measuring tubes 23 . 24 The latter also experience much smaller oscillating aerodynamic forces (fan effect). Due to the absence of these disturbing effects, ie the inherently difficult momentum to control and the higher aerodynamic damping, Coriolis mass flowmeters are 100 according to the present invention in total more accurate than those of the prior art.

Because the "meter tube fluid magnet magnet holder" system is much lighter and therefore has a much higher natural frequency than the heavier prior art systems, Coriolis mass flowmeters operate 100 according to the present invention at higher frequencies, such as according to the invention in the range of 200 Hz or at even higher frequencies, than those according to the prior art. This makes Coriolis mass flowmeters 100 according to the present invention not only more accurate measurement, but also less sensitive to external influences such as vibration, shock waves u. Ä. As such according to the prior art.

Coriolis mass flowmeters 100 The present invention also has a completely new minimalist architecture for this class of gauges. They have more coils 1 . 2 . 3 . 4 . 5 . 6 and permanent magnets 11 . 12 . 13 . 14 . 15 . 16 as such according to the prior art. Dimensional deviation and tolerance critical components are reduced to a very small number. So can a (except for a seal) only two-part housing (housing body 100 and housing cover 30 ) are used with a solid base or housing body 10 which allows it to flow dividers and coupling elements for the measuring tubes 23 . 24 to renounce. The possibility of using a printed circuit board 33 rather than internal wiring found in prior art Coriolis mass flowmeters, further reduces the body 100 arranged movable or swingable components. The fewer components or components are used, the less dimensional deviations and tolerances can occur in the production of the individual parts and assembly of the devices. Also for this reason are Coriolis mass flowmeters 100 according to the present invention, especially for small and very small measuring devices 100 , more accurate and more reliable than those of the prior art.

For Coriolis mass flowmeters 100 according to the present invention are both a one-sided phase measurement, ie on only one of the two measuring tubes 23 . 24 , as well as a two-sided phase measurement, ie on each of the two measuring tubes 23 . 24 , possible. The number of used coils 1 . 2 . 3 . 4 . 5 . 6 may vary accordingly. For example, in the case of double-sided phase measurement, there are a total of six coils, ie two for the two vibration exciters 42 . 45 and two times two for the four vibration transducers 41 . 43 . 44 . 46 as in the 2 and 3 shown, necessary.

With one-sided phase measurement, however, only four coils 1 . 2 . 3 . 5 necessary, ie two coils 2 . 5 for the two vibration exciters 42 . 45 and 2 for the two vibration sensors 41 . 43 , In this case (the one-sided phase measurement) can be two coils, eg coils 1 . 3 or coils 4 . 6 either missing or existing but not connected or connected. In this case (the one-sided phase measurement), it also makes sense compared to the missing (or not switched) coils 1 . 3 or 4 . 6 lying permanent magnets, ie permanent magnets 11 . 13 or 14 . 16 by non-magnetic bodies of the same shape and mass.

For Coriolis mass flowmeters 100 According to the present invention, opposing coils can be used 1 . 4 ; 2 . 5 ; 3 . 6 electrically, depending on the desired type of vibration excitation and the phase measurement, be connected to each other in parallel or in series. Connected in series Coils can also be combined (in pairs) into one (eg longer) coil. Opposite permanent magnets 11 . 14 ; 12 . 15 ; 13 . 16 may be repulsive (ie - / - or + / +) or attractive (+/- or - / +) depending on the coil configuration and circuitry.

To the magnetic fields of opposing permanent magnets 11 . 14 ; 12 . 15 ; 13 . 16 To shield, can (according to the invention with strong permanent magnets) according to the invention also magnetically shielding films and other magnetic shielding elements are used.

LIST OF REFERENCE NUMBERS

1

 Kitchen sink

2

Kitchen sink

3

Kitchen sink

4

Kitchen sink

5

Kitchen sink

6

Kitchen sink

7

 addendum

8th

 fastener

9

 fastener

10

 housing body

11

 permanent magnet

12

permanent magnet

13

permanent magnet

14

permanent magnet

15

permanent magnet

16

permanent magnet

17

 magnetic holder

18

magnetic holder

19

magnetic holder

20

magnetic holder

21

magnetic holder

22

magnetic holder

23

 measuring tube

24

 measuring tube

25

Opening the flow inlet 31

26

Opening of the flow outlet 32

27

 threaded connection

28

 threaded connection

29

 Grommet

30

 housing cover

31

 flow inlet

32

 flow outlet

33

 circuit board

34

Flow channel to the measuring tube 23

35

Flow channel to the measuring tube 24

36

 Part of the housing forming additional material

37

 collar

38

 round channel

41

 Vibration Sensors

42

vibration exciter

43

 Vibration Sensors

44

Vibration Sensors

45

 vibration exciter

46

 Vibration Sensors

100

 Coriolis mass flowmeter

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 6776052 B2 [0002]
• EP 1429119 A1 [0002]
• US 5349872 [0007]

Claims (15)

Coriolis mass flowmeter with - a housing body ( 10 ), which has a flow inlet ( 31 ) and a flow outlet ( 32 ) for a fluid medium, - two spaced-apart measuring tubes ( 23 . 24 ) attached to the housing body ( 10 ) and the flow inlet ( 31 ) and the flow outlet ( 32 ), - at least one electrically controllable vibration exciter ( 42 . 45 ) for each measuring tube ( 23 . 24 ), the vibration exciter ( 42 . 45 ) is adapted to the measuring tube ( 23 . 24 ) and at least two electrically controllable vibration sensors ( 41 . 43 . 44 . 46 ), the vibration sensors ( 41 . 43 . 44 . 46 ) are adapted to the vibration of at least one of the two measuring tubes ( 23 . 24 ), characterized in that the vibration exciters ( 42 . 45 ) and the vibration sensors ( 41 . 43 . 44 . 46 ) spatially fixed between the two measuring tubes ( 23 . 24 ) on the housing body ( 10 ). Coriolis mass flowmeter according to claim 1, characterized in that as a vibration exciter ( 42 . 45 ) and transducers ( 41 . 43 . 44 . 46 ) electromagnetic coils ( 1 . 2 . 3 . 4 . 5 . 6 ), each coil ( 1 . 2 . 3 . 4 . 5 . 6 ) with one on one of the measuring tubes ( 23 . 24 ) permanent magnet ( 11 . 12 . 13 . 14 . 15 . 16 ) cooperates. Coriolis mass flowmeter according to claim 1 or 2, characterized in that on the housing body ( 10 ) a construction ( 7 ) at which the vibration exciters ( 42 . 45 ) and transducers ( 41 . 43 . 44 . 46 ). Coriolis mass flowmeter according to claim 3, characterized in that the Ankonstruktion ( 7 ) at least one board ( 33 ), on which the electrically controllable vibration exciters ( 42 . 45 ) and transducers ( 41 . 43 . 44 . 46 ) and on the board ( 33 ) formed conductor tracks are controlled. Coriolis mass flowmeter according to one of the preceding claims, characterized in that at least one measuring tube ( 23 . 24 ) two vibration sensors ( 41 . 43 ; 44 . 46 ) assigned. Coriolis mass flowmeter according to claim 5, characterized in that in the Coriolis mass flow meter ( 100 ) two vibration exciters ( 42 . 45 ) and two or four vibration transducers ( 41 . 43 . 44 . 46 ) are provided. Coriolis mass flowmeter according to one of the preceding claims, characterized in that the vibration exciter ( 42 . 45 ) on the measuring tube ( 23 . 24 ) in the middle between the ends of the measuring tube ( 23 . 24 ) is arranged. Coriolis mass flowmeter according to one of the preceding claims, characterized in that a vibration sensor ( 41 . 43 . 44 . 46 ) on the measuring tube ( 23 . 24 ) between the one end of the measuring tube ( 23 . 24 ) and the vibration exciter ( 42 . 45 ) is arranged and another oscillating transducer ( 41 . 43 . 44 . 46 ) on the same measuring tube ( 23 . 24 ) between the other end of the measuring tube ( 23 . 34 ) and the vibration exciter ( 42 . 45 ) is arranged. Coriolis mass flowmeter according to one of claims 2 to 8, characterized in that the measuring tubes ( 23 . 24 ) are arranged parallel to each other and the permanent magnets ( 11 . 12 . 13 ; 14 . 15 . 16 ) on the measuring tubes ( 23 . 26 ) are mounted opposite one another and oriented in such a way that the permanent magnets ( 11 . 12 . 13 ; 14 . 15 . 16 ) attract or repel. Coriolis mass flowmeter according to one of the preceding claims, characterized in that the housing body ( 10 ) of the Coriolis mass flowmeter ( 100 ) is formed as a solid block of material in the as flow inlet ( 31 ) and as a flow outlet ( 32 ) on opposite end faces in each case an opening ( 25 . 26 ), wherein in each case two flow channels ( 34 . 35 ) from every opening ( 25 . 26 ) to an exit in a side surface of the housing body ( 10 ) and wherein the output of one of the flow channels ( 34 . 35 ) into the one measuring tube ( 23 . 24 ) and the output of the other of the flow channels ( 35 . 34 ) into the other measuring tube ( 24 . 23 ) opens. Coriolis mass flowmeter according to one of the preceding claims, characterized in that the ends of the measuring tube ( 23 . 24 ) on the housing body ( 10 ). Coriolis mass flowmeter according to claim 11, characterized in that the ends of the measuring tube ( 23 . 24 ) with the housing body ( 10 ) are welded, wherein on the housing body ( 10 ) Additional material for forming the weld is provided. Coriolis mass flowmeter according to one of claims 10 to 12, characterized in that in the solid housing body ( 10 ) a cable feedthrough ( 29 ) between the opening ( 25 ) of the flow inlet ( 31 ) and the opening ( 26 ) of the flow outlet ( 32 ) formed from the side surface with the outputs of the flow channels ( 34 . 35 ) extends to the opposite side surface. Coriolis mass flowmeter according to one of claims 4 to 13, characterized in that on the board ( 33 ) Components of the measuring electronics are arranged. Coriolis mass flowmeter according to one of the preceding claims, characterized in that the two measuring tubes ( 23 . 24 ) are interconnected by means of one or more transverse struts or gusset plates.

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