DE10347879A1 - Field measurement assembly, to give a measured value of a material flow within a pipe for process control, has coverings on the material and the environment sides with compound fiber layers between them for embedded sensors - Google Patents

Abstract

The field measurement assembly (1a), to give a measured value of a material flowing (S) within an enclosed pipe (2) at a processing assembly, has a covering (4) on the side towards the material and a cover (6) on the side towards the ambient environment. The monitor is between the two coverings, to give measurements with or without contact with the material. The space between the coverings is filled with layers (19) of a compound fiber material using glass, carbon or synthetic fibers. A connector (8) gives the power supply and signal transmission connections. Three thermal sensors (56-58) are embedded within the layers, together with a signal processing unit (24). In other configurations, the sensors can register pressures, or inductive magnetic flows.

Description

The The invention relates to a measuring device for determining the value of a measured quantity of a substance within a bounded space in a process plant according to the preamble of claim 1, and a method for producing such meter according to the preamble of Claim 8.

Generic measuring devices are often referred to as "field devices", for Demarcation in particular against Laboratory instruments, since they are in the "field", in a procedural Plant can be used as part of a process measuring and control system. Their task is to record a value representing the measured value physical or chemical size, their forwarding and / or transformation and the output of the sought measured value to a higher-level process measuring and control system. To the terms used and the technical Background to the generic "field devices" see also the lexicon Measurement and Automation Technology, Edited by Elmar Schrüfer, VDI-Verlag Dusseldorf 1992, P. 364 ff and the respective entries there for special measuring device types. The prior art described there is intended to be based on the present application become.

Generic measuring devices are especially for the determination of the measured quantities pressure, temperature, level, Volume or mass flow and composition of fluids in pipelines or containers used. Independently from the respective measured variable to be detected is common to them that they have a material-side device boundary surface, this is the pipe inner wall in a pipeline and the case of a container Container inner wall, and an environment-side device boundary surface that is in each case in contact with the environment in the outer surface of the Meter. These are generic measuring devices today depending on the device type and measure very much constructed differently, especially with regard to the housing structure and the introduction of the sensor and possible signal converter in the Casing. The usual today Manufacturing process is shaped of relatively small series sizes per device variant on the one hand and a high number of device variants on the other hand, as well a largely manual and therefore complex and costly Production.

It The object of the present invention is to provide a generic measuring device which economical and built using modular manufacturing methods and on simple way configured during production for different measurands may be, as well as to provide a method for producing a generic measuring device.

The Task is solved with regard to the measuring device by the characterizing Features of claim 1, and in terms of the method for its Production by the characterizing features of claim 8.

Thus, according to the invention the space between the fabric side and the environment side Device limitation area completely or partially formed by layers of a fiber composite material. The sensor can advantageously - while leaving his if necessary, substance-contacting Parts - in the layers of fiber composite material to be embedded.

The Forming the gap between the material side and the environment side Device limitation area completely or partially by laminating a fiber composite a basic module as a device platform, in the other part systems like in particular the sensor, but Also embedded signal converter and possibly required shielding can be and the above also outwards take over the protective function of the housing can.

Inventive measuring devices can their different measurement tasks so be adapted by that each for the intended measuring task is suitable sensor, possibly together with a signal converter, in the manufacture of the meter at a suitable Place in the manufacturing process in the layers of fiber composite material is embedded. Fiber composite is suitable as a base material for the instrumentation platform especially because it has a high mechanical stability and load capacity with great chemical resistance combines.

In Advantageously, the gap between the fabric side and the environment-side device boundary surface in particular completely or partially by glass fiber reinforced or carbon fiber reinforced or Aramid fiber reinforced or PE fiber reinforced or kevlar-reinforced Be formed plastic material.

Inventive measuring devices can, for example be formed by a temperature sensor and / or as a sensor a pressure sensor and / or an inductive flow sensor and / or an ultrasonic flow sensor and / or a level sensor are embedded.

A further advantageous embodiment of the invention is characterized in that the space between the fabric side and the surrounding device limiting surface is formed in a adjacent to the fabric-side device boundary surface first subspace by a measuring tube made of metal, ceramic, glass, fiber composite material or plastic and in an adjacent to the environmental device boundary surface second subspace by layers of at least one fiber composite material. The advantage of such an embodiment is that the measuring tube can be used as a standard part of the existing production, and the other subsystems of a generic measuring device are then embedded in the layers of fiber composite material.

The inventive measuring device is characterized thus also due to a very high flexibility regarding the inclusion of existing production parts and production steps out.

A very advantageous variant of the manufacturing method for a generic measuring device is characterized characterized in that the space between the stoffsei term and the environment-side device boundary surface completely or partially by layering winding fiber composite semifinished product is formed.

Of the Sensor can then be released, if necessary material contact Parts are wrapped in the layers of fiber composite semi-finished product.

At the Winding can in an advantageous variant of the method of Space between the fabric side and the environment side Device boundary surface initially off Layers of resin impregnated Wrapped semifinished fiber and then cured. In another advantageous Variant may be the space between the fabric side and the environment-side device boundary surface too first wound from layers of dry semi-finished fiber and then under Vacuum the resin to be retracted.

range way can also different fiber composites are wound up. So can For example, electrically non-conductive fiber composites and electrically conductive Fiber composites are wound up successively.

Further advantageous embodiments and improvements of the invention and Further advantages can be found in the further subclaims.

Based of the drawings, in which 5 embodiments the invention are shown, the invention and others advantageous embodiments and improvements of the invention and others Advantages closer explained and described.

It demonstrate:

1 A first embodiment of a measuring device according to the invention as a temperature measuring device,

2 A second embodiment of a measuring device according to the invention as an ultrasonic flowmeter,

3 A third embodiment of a measuring device according to the invention as a pressure gauge,

4 A fourth embodiment of a measuring device according to the invention as an optical process analyzer, and

5 to 20 the individual steps for producing a fifth embodiment of a measuring device according to the invention as a magneto-inductive flow meter according to the invention.

1 shows a measuring device according to the invention 1 , which is a measuring tube through which the substance to be measured flows in the direction of the arrow S 2 with a fabric-side and an environmental device boundary 4 . 6 includes. Between the fabric-side device boundary surface 4 and the environment-side device boundary surface 6 is the measuring device 1 from a sequence of layers 19 formed by fiber composite material.

Partly embedded in the environment-side device limit is a connection device 8th , The connection device 8th can either serve only for contacting and even do not contain electronic components, but only connection elements with which the meter is electrically connected to its system environment (power supply and signal dissipation). But it can also already contain a variety of functional modules for signal processing, filtering, storage and transmission - either via bus cable or wirelessly using radio stations, Bluetooth or other common signal transmission protocols - and is then commonly referred to as a transmitter. In the 1 If a wireless communication interface is installed, the wireless communication is indicated by the arrow P.

The measuring tube 2 is made by a fiber composite winding technique. The surface contour of the measuring tube 2 can be designed within wide limits due to the winding technique. So shows 1 as an example a measuring tube with a thickening to the two lateral sealing surfaces 5 and towards the middle, in between there is a convex constriction. The connection device 8th is partially embedded in the measuring raw wall and glued or pressed into it.

In the sequence of layers 19 made of fiber composite material are three temperature sensors 56 . 57 . 58 and an electronic signal processing module 24 embedded. The signal processing board 24 is electric with the temperature sensors 56 . 57 . 58 and the connection device 8th and causes a sensor-near preamplification and signal conversion to a standardized sensor signal, for example, 4-20mA, which then the connection device 8th is supplied.

A first temperature sensor 56 is very close to the fabric-side device boundary surface 4 embedded, a second temperature sensor 57 is very close to the environmental device boundary surface 57 embedded, and a third temperature sensor 58 is close to the fabric-side device boundary surface 4 but in the flow direction by a distance x from the first temperature sensor 56 embedded away.

With the temperature sensors 56 and 58 lets the temperature of the pipe through 2 to measure flowing substance. From the difference of the two temperature sensors 56 . 57 determined temperature values can be calculated with knowledge of the geometry and the material properties of the fiber composite material, the thermal heat flow and from this the energy exchanged between the medium and the environment. From the difference of the two temperature sensors 56 . 58 determined temperature values can be determined with knowledge of the heat capacity and the density of the flowing substance, the flow velocity by known methods of thermal flow measurement. The meter after 1 is thus an inventive multiple measuring device for measuring temperature, flow and heat flow.

2 shows a variant of a measuring device according to the invention, in which, with the exception of the sensor, the structure and the production method are the same as in the 1 shown measuring device. At the meter after 2 was based on the same technology platform as the device 1 realized an ultrasonic flowmeter. Instead of the temperature sensors 56 . 57 . 58 out 1 here were an ultrasonic transmitter 67 and each a first, upstream ultrasonic receiver 66 and a second ultrasonic receiver located downstream of the transmitter 68 on the fabric-side device boundary surface 4 embedded in the layer sequence of fiber composite material. With the measuring device realized in this way, the flow velocity of the substance in the measuring tube can be determined according to the method of transit time difference measurement known in metrology 2 measure up. One uses the effect that the sound propagates contrary to the flow velocity S at a different speed than with the flow velocity. Now from the ultrasound transmitter 67 a signal simultaneously delivered against and in the direction of flow, as can be deduced from the time difference with which the signal at each of the two receivers 66 . 68 is registered, with the aid of known calculation methods, the flow velocity of the substance in the measuring tube 2 determine.

A third, based on the same technology platform as the gauges 1 or 2 described embodiment of a measuring device according to the invention shows 3 the example of a pressure gauge. As a sensor here are an absolute pressure sensor 76 and one of two by means of a connecting tube 79 connected pressure sensors 78 and 79 formed differential pressure sensor in the layer sequence 19 embedded in fiber composite material.

The absolute pressure sensor may be, for example, a commercially available micromechanically manufactured pressure sensor chip, as it is manufactured and supplied in large quantities and in various accuracy and reliability classes of the sensor industry and used for example in automotive technology for tire pressure measurement while driving or to measure the cylinder pressure in the engine becomes. When embedding in the sequence of layers 19 made of fiber composite material of the measuring device 3 Care must be taken that the hydraulic coupling between the pressure-sensitive part of the pressure sensor 76 and the substance inside the measuring tube 2 is not blocked.

The differential pressure sensor comprises a first part sensor 78 in hydraulic contact with the substance inside the measuring tube 2 and a second part sensor 77 in hydraulic / pneumatic contact with the environment, both connected by a connecting tube 79 , The pressure-sensitive part of the differential pressure sensor is located inside the tube 79 , so that in this way the pressure difference between the inside of the measuring tube and the environment of the meter 1c is measured.

A fourth example, which shows how relatively uncomplicated on the basis of the technology platform according to the invention a variety of measuring instruments by embedding different sensors in the same same, formed of fiber composite layer sequences between the material side and the environment side device interface let realize is in 4 an optical analyzer. Here are in the sequence 19 made of fiber composite a light emitter 86 For example, a laser diode tuned to a particular wavelength or an LED with a narrow band optical filter or even a conventional cold light lamp with a corresponding filter, and an optical receiver downstream of the transmitter 88 in the sequence of layers 19 embedded. light source 86 and light receiver 88 can also work in the non-visible part of the electromagnetic spectrum, for example in the infrared or ultraviolet. The material-side device boundary surface 4 is between the light source 86 and the light receiver mirrored. This is accomplished by sandwiching two reflective metal foils or sheets in the fiber composite layer sequence, either indirect contact with the interior of the measuring tube 2 or by a very thin, optically transparent first winding layer of the substance inside the measuring tube 2 separated and thus protected. That from the light source 86 Outgoing light is at the mirroring 4a and 4b reflected several times, so that increases the effective optical path length of the light in the medium. In this way, for example, an absorption meter is realized, the light absorption in the medium from the ratio between the at the light receiver 88 registered light intensity and that of the light source 86 emitted light intensity according to the known Lambert-Beer's law (see relevant textbooks of physics) determined and thus allows conclusions about the composition of the substance. Of course, other known from the prior art optical measuring methods, such as laser Doppler anemometry for speed measurement, can be realized in a similar manner.

The 5 to 20 show the example of a magnetic inductive flow meter, which is manufactured on the basis of the same technology platform, gradually the construction and the production of a measuring device according to the invention.

As a first step, a cylindrical core K is prepared ( 1 ). The core K may be made of metal, such as aluminum, or from a formed by overpressure in molded plastic tube.

Immediately to the core K, in a second step ( 6 ) first electrodes 23 , here for electrical coupling to the medium, together with the electrical Ableitun gene 26 applied and fixed by adhesive dots. The electrodes may consist of bendable sheet metal, metal foil or also of conductive plastic.

Now in the third step ( 7 ) a first, inner layer 19a wound. This can consist either of resin-impregnated fibers in the form of a so-called roving or semi-finished fiber products in the form of, for example, a tailor-made fabric with suitable individual fiber layers tailored to the total width of the measuring tube.

On this first layer 19a in the fourth step ( 8th ) Measuring electrodes 20 . 20a with the appropriate electrical leads 26 fixed and in the fifth step ( 9 ) of some other semi-finished fiber layers 19b wrapped.

Accordingly, in the sixth step ( 10 ) with the shield electrodes 22 . 22 ' . 22a . 22a ' and the signal leads 26 method. Subsequently, in the seventh step ( 11 ) the wall through a few more layers 19c thickened.

In the eighth step ( 12 ) becomes a signal converter assembly 24 with their supply line 26 fixed and in the ninth step ( 13 ) from another layer 19d covered.

Next are the parts of the magnet system, the ferromagnetic core 32 in step 10 ( 14 ) and the excitation coils 30 . 30a in step 11 ( 15 ), again initially fixed provisionally, and then with a few more layers 19e wrapped and finally attached (step 12 . 16 ). The excitation coils are mounted so that the magnetic field in the tube interior perpendicular to the tube center axis 3 and perpendicular to the connecting line between the measuring electrodes 20 . 20a runs.

at The magnet system has a very high positioning accuracy in particular to a low twist, if a high accuracy should be achieved. In accordance with careful winding is the achievable geometric precision very high. So you can do a twisting of the coils and the core reach less than 1 °.

Then, in step thirteen ( 17 ) a shielding layer 40 of conductive material, for example of a semi-finished fiber of electrically conductive material such as conductive carbon fibers, wound up, and these in step fourteen ( 18 ) again with some last outer protective layers 19f wrapped. The outer protective layers 19f protect against all external influences, so that the meter as a whole the appropriate protection class, for example IP 68 , enough. You can also consist of other semi-finished, for example, aramid fiber reinforced material when the measuring tube is made of GFK semifinished product.

When winding, the measuring signal lines must 26 and the leads to the coils 30 and to the transducer assembly 24 be passed between the individual winding layers.

If the fiber composite layers were built up of dry semifinished product, then now in step 15 ( 19 ) The resin drawn under vacuum and then cured.

On the finished wound measuring tube is then still in the step 16 ( 20 ) the connection device 8th attached. This can be done either by screwing or gluing, or again by wrapping with band-shaped semifinished product, so that the connection sockets and possibly the operating and display elements remain free. Finally, the core is removed.

Also in the production of other conceivable inventive measuring devices, the production order remains in principle as in the 5 to 20 described. Only the type of sensors to be embedded and other subsystems will change depending on the type of instrument to be built.

The Embodiments described above do not give finally all possible embodiments of measuring devices according to the invention again. Also all not mentioned here, but themselves by combinations of the embodiments described herein or parts thereof resulting further embodiments are therefore intended to be be included in the present application.

Claims (17)

Measuring device for determining the value of a measured variable of a substance within a bounded space in a process plant, with a material-side device boundary surface and an environmental device boundary surface and at least one attached between the fabric side and the surrounding device boundary surface, touching or non-contact, measuring sensor, characterized in that the space between the fabric side and the environment side device boundary surface is formed wholly or partly by layers of a fiber composite material. gauge according to one of the preceding claims, characterized characterized in that the sensor is released if necessary, substance-contacting Parts embedded in the layers of fiber composite material. gauge according to claim 1 or 2, characterized in that a with the Sensor of connected signal converter completely or partially in the Layers of fiber composite material is embedded. gauge according to claim 3, characterized in that the intermediate space between the fabric-side and the environment-side device boundary surface completely or partially by glass fiber reinforced or carbon fiber reinforced or aramid fiber reinforced or PE fiber reinforced or Kevlar reinforced Plastic material is formed. gauge according to one of the preceding claims, characterized characterized in that the material-side device boundary surface a closed pipe inner surface is. gauge according to one of the preceding claims, characterized in that the sensor is a temperature sensor and / or a pressure sensor and / or an inductive or Coriolis or vortex or ultrasonic flow sensor and / or a capacitive or ultrasonic or microwave level sensor and / or an optical analyzer. gauge according to one of the preceding claims, characterized characterized in that the space between the fabric side and the environment side device tebegrenzungsfläche in one adjacent to the fabric-side device boundary surface first subspace through a measuring tube made of metal, ceramic, glass, fiber composite material or plastic and in the adjacent to the environmental device boundary surface second subspace by layers of at least one fiber composite material is formed. Method for producing a measuring device for the determination the value of a measurand of a substance within a bounded space in a procedural Plant, which has a material-side device boundary surface and an environment-side device boundary surface as well at least one between the fabric side and the environment side Device boundary surface attached, touching or contactless working, comprises sensor, characterized in that the space between the fabric side and the environment side Device limitation area completely or partially formed by layers of a fiber composite material becomes. Method according to claim 8, characterized in that that the sensor, releasing its possibly material contacting Parts embedded in the layers of fiber composite material. A method according to claim 8 or 9, characterized in that a signal converter connected to the sensor is completely or partially embedded in the layers of the fiber composite material. Method according to one of claims 8 to 10, characterized that the space between the material side and the environment side Device limitation area completely or partially by glass fiber reinforced or carbon fiber reinforced or Aramid fiber reinforced or PE fiber reinforced or kevlar-reinforced Plastic material is formed. Method according to one of claims 8 to 11, characterized that the space between the material side and the environment side Device limitation area completely or partially by layering winding fiber composite semifinished product is formed. Method according to one of claims 8 to 12, characterized that the sensor, releasing its possibly material contacting Parts wrapped in the layers of fiber composite semi-finished product. Method according to one of claims 8 to 13, characterized that the space between the material side and the environment side Device boundary surface off Layers of resin impregnated Semi-finished fiber wound and then cured. Method according to one of claims 8 to 13, characterized that the space between the material side and the environment side Device boundary surface off Wrapped layers of dry semi-finished fiber and then under Vacuum the resin is retracted. Method according to one of claims 8 to 15, characterized that in some areas different fiber composite materials are wound up. Method according to claim 16, characterized in that that partially electrically non-conductive fiber composites and electrically conductive Fiber composites are wound up.