SYSTEM FOR DETERMINING AND MONITORING AT LEAST ONE PROCESS VARIABLE OF A MEDIUM

Abstract

A system for determining a process variable of a medium arranged in a container is disclosed, including an optical fiber Bragg sensor with an optical waveguide with a fiber Bragg grating, a signal generating unit designed to generate an optical input signal and couple it into the waveguide, a receiving unit designed to receive an optical output signal from the waveguide and converts it into an electrical output signal, and an evaluating unit which determines the process variable using the electrical output signal, wherein a subsection of the optical waveguide is arranged inside or in a wall of the container, the subsection designed such that the fiber Bragg grating is affected by the process variable to be determined of the medium.

Claims

1. A system for determining at least one process variable of a medium arranged in a container, comprising: an optical fiber Bragg sensor with an optical waveguide including at least one fiber Bragg grating, which is configured to be affected by the at least one process variable of the medium to be determined; a signal generating unit embodied to generate an optical input signal and to couple the input signal into the optical waveguide; a receiving unit embodied to receive an optical output signal from the optical waveguide and to convert the optical output signal into an electrical output signal; and an evaluating unit configured to determine the at least one process variable based upon the electrical output signal, wherein a subsection of the optical waveguide is disposed within the container or in or adjacent a wall of the container, and wherein the subsection of the optical waveguide includes the at least one fiber Bragg grating arranged to interact with the medium.

2. The system of claim 1, wherein the optical waveguide includes a core and a cladding surrounding the core at least partially, wherein the core is composed of a material having a higher refraction index than a material of the cladding.

3. The system of claim 1, wherein the optical waveguide includes of a fiber having a higher refraction index than the medium interacting with the at least one fiber Bragg grating.

4. The system of claim 1, wherein the optical waveguide includes Bragg grating groups at defined intervals, wherein a fiber Bragg grating group is configured such that at least two different process variables can be determined selectively.

5. The system of claim 1, wherein the optical waveguide is embodied such that at least one fiber Bragg grating or at least one fiber Bragg grating of a fiber Bragg grating group interacts with the medium via an evanescent field to enable determining the at least one process variable of the medium.

6. The system of claim 1, wherein the optical waveguide includes a surface layer in a subregion of the optical waveguide, wherein the surface layer is embodied to increase a sensitivity of the at least one fiber Bragg grating to the the at least one process variable of the medium to be determined.

7. The system of claim 1, wherein a wall of the container includes a duct configured such that at least one of two end regions of the optical waveguide extends out of the container.

8. The system of claim 1, wherein a wall of the container includes a coupling component configured such that at least one of two end regions of the at least one optical waveguide is connected or connectable to the coupling component.

9. The system of claim 1, wherein the wall of the container includes at least one coupling region embodied as a window transparent to the optical input signal and optical output signal, and wherein at least one of two end regions of the at least one optical waveguide is connected or connectable to a lens system.

10. The system of claim 1, wherein the optical waveguide is arranged at least partially on a substrate or is integrated at least partially into a substrate.

11. The system of claim 10, wherein the substrate is at least a portion of a wall of the container or is a coating on a wall of the container.

12. The system of claim 10, wherein the receiving unit is disposed on the substrate or integrated into the substrate.

13. The system of claim 1, wherein the receiving unit is a photoelectric converter.

14. The system of claim 1, wherein the signal generating unit, the receiving unit and/or the evaluating unit are diposed outside the container.

15. The system of claim 1, further comprising a control system configured to communicate with the evaluating unit, the communication being wired or wireless.

16. The system of claim 1, wherein the container is a single-use or disposable container.

17. The system of claim 1, wherein the medium is a fluid medium, including a gas, gas mixture, liquid, granulate and/or powder.

18. The system of claim 1, wherein the optical fiber Bragg sensor is embodied to determine at least one of the following physical or chemical process variables: temperature, pressure, fill-level, flow rate, mechanical stress, pH value, turbidity, concentration of a substance, an atomic or molecular gas, or a portion of at least one gaseous, liquid, or solid component.

19. The system of claim 1, wherein the optical fiber Bragg sensor is embodied to determine the color of the medium.

20. The system of claim 1, wherein the optical fiber Bragg sensor is embodied to determine at least one metabolite or the concentration of a metabolite, wherein the metabolite is an intermediate product in a biochemical metabolic process.

21. The system of claim 1, wherein the optical input signal is coupled into the optical waveguide at a power that is less than the maximum power permissible for an explosion-hazard area.

22. The system of claim 1, wherein the system is powered at a power that is less than the maximum power permissible for the explosion-hazard area.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The present disclosure is explained in greater detail with reference to the following figures. Illustrated are:

[0038] FIG. 1A shows a schematic illustration of a first embodiment of the system according to the present disclosure;

[0039] FIG. 1B shows the section A shown in FIG. 1A, in an enlarged illustration;

[0040] FIG. 2A shows a schematic illustration of an embodiment of the fiber Bragg sensor; and

[0041] FIG. 2B shows the section B shown in FIG. 2A, in an enlarged illustration.

DETAILED DESCRIPTION

[0042] FIG. 1A shows a schematic illustration of a first embodiment of the system according to the present disclosure for determining and/or monitoring at least one process variable of a medium 1 arranged in a container 2. In the case shown, the container 2 is a bag-shaped, flexible container, such as a single-use or disposable bag. It goes without saying that the present disclosure can be used in connection with all possible containers 2.

[0043] The system according to the present disclosure comprises an optical fiber Bragg sensor 3 with an optical waveguide 4, which comprises at least one fiber Bragg grating 5 serving as filter element. As can be seen in FIG. 1B, the optical waveguide consists of a core 9 and a cladding 10. The cladding 10 surrounds the core 9 at least partially. So that the electromagnetic input signals or the light propagate in the core 9 with as little a loss as possible, the material of which the core 9 consists has a higher refraction index than the material of which the cladding 10 consists.

[0044] A subsection TA of the optical waveguide 4 is arranged in the container 2. In an alternative not shown separately, the optical waveguide 4 is arranged in the wall 8 of the container 2 and is thus an integral part of the container 2. The subregion TA of the optical waveguide 4 extending in the internal space or in the interior of the container 2, or the subregion TA of the optical waveguide 4 interacting with the medium 1, is designed such that the at least one fiber Bragg grating 5 (in the case shown, a group of two fiber Bragg gratings 5 and a single fiber Bragg grating 5 are shown) is affected by the at least one process variable to be determined of the medium 1. The fiber Bragg grating groups or fiber Bragg gratings 5 arranged at defined intervals in the optical waveguide 4 are designed such that at least two different process variables can be determined selectively. Various designs of fiber Bragg sensors 3 for determining or monitoring different process variables have already previously been described and are disclosed in the cited prior art in detail.

[0045] The signal generating unit 6 preferably, a broadband light source generates at least one optical input signal and couples it into the optical waveguide 4. Furthermore, a receiving unit 7 is provided, designed such that it receives at least one optical wavelength-coded output signal from the one optical waveguide 4 and converts it into an electrical output signal. Based upon the at least one electric output signal, an evaluating unit 17 determines the at least one process variable.

[0046] In the embodiment of the system according to the present disclosure shown in FIG. 1A, the electrical/electronic components, signal generating unit 6, receiving unit 7, and evaluating unit 17 are arranged outside the container 2. The optical waveguide 4 is connected in a fixed or removable manner to the container 2 via a duct 12 or a coupling component 13. Evaluating units for determining or monitoring the process variable(s) are known from the prior art. In the case shown, the evaluating unit 17 communicates with a remotely arranged control room 18 by radio. Naturally, wired communication is also possible. Alternatively, all or at least a portion of the electric/electronic components 6, 7, 17 can be arranged remotely from the container 2 at any distance, by dimensioning the optical waveguide 4 accordingly. As already mentioned previously, it is also known to operate a plurality of optical waveguides 4 via corresponding connections by means of, for example, only one signal generating unit 6, receiving unit 7, and evaluating unit 17. The process variables of various containers 2 or batches can thus be determined and monitored simultaneously by one evaluating unit 17.

[0047] FIG. 2A shows a schematic illustration of an embodiment of the system according to the present disclosure for determining and/or monitoring at least one process variable of a medium 1 arranged in a container 2. Below, reference is made only to the system components in which the embodiment shown in FIG. 2A differs from the embodiment shown in FIG. 1A.

[0048] As can be seen in FIG. 2B, which shows the section marked B in FIG. 2A in an enlarged illustration, the subsection TA of the optical waveguide 4 arranged in the container 2 is designed such that at least one fiber Bragg grating 5 interacts with the medium 1 via an evanescent field for the purposes of determining a process variable of the medium 1. In the case shown, in the subregion TB, a surface layer 11 is mounted onto the optical waveguide 4. The surface layer 11 is optional and designed such that the at least one fiber Bragg grating 5 has an increased sensitivity to the process variable to be measured or monitored.

[0049] The subsection TA of the optical waveguide 4 arranged in the container 2 is connected with its end region EB to the coupling region 14. This coupling region 14 is designed such that it is transparent to the radiation or the light conducted in the optical waveguide 4. The optical coupling of the light between the subsection TA of the optical waveguide 4 in the container 2 and the optical waveguide 4 outside the container 2 takes place via at least one optical component 15, such as a lens. As already mentioned, the subsection TA can, depending upon the measuring or monitoring task, be arranged on or in a substrate 16.