VIBRONIC MULTISENSOR

Abstract

A method for determining and/or monitoring a concentration of maltodextrin and/or maltose in a mashing process comprises method steps as follows: providing a mash, heating the mash to at least one predeterminable temperature, determining the density of the mash determining the velocity of sound in the mash, ascertaining a concentration of maltodextrin and maltose in the mash, and ascertaining the concentration of maltodextrin and/or maltose in the mash.

Claims

1-8. (canceled)

9. A method for determining and/or monitoring a concentration of maltodextrin and/or maltose in a mashing process, comprising: providing a mash; heating the mash to at least one predeterminable temperature; determining the density of the mash; determining the velocity of sound in the mash; ascertaining a concentration of maltodextrin and maltose in the mash; and ascertaining the concentration of maltodextrin and/or maltose in the mash.

10. The method as claimed in claim 9, further comprising: determining a temperature of the mash.

11. The method as claimed in claim 10, wherein an influence of temperature is taken into consideration in determining density and/or velocity of sound.

12. The method as claimed in claim 9, wherein concentration of sum of maltodextrin and maltose in the mash is ascertained based on density.

13. The method as claimed in claim 9, wherein ratio of maltodextrin and maltose is ascertained based on velocity of sound in the mash.

14. The method as claimed in claim 13, wherein concentration of maltodextrin and/or maltose is ascertained based on the ratio of maltodextrin and maltose.

15. The method as claimed in claim 13, further comprising: comparing at least one value for the velocity of sound in the mash with at least one reference value or with a value of a characteristic line for the velocity of sound of maltodextrin and/or maltose as a function of concentration of maltodextrin and/or maltose.

16. The method as claimed in claim 9, wherein a sensor unit is excited by means of a excitation signal to execute mechanical oscillations, the mechanical oscillations are received by the sensor unit and converted into a first received signal, a transmitted signal is transmitted from the sensor unit and a second received signal received by the sensor unit, and density is ascertained based on the first received signal and velocity of sound is ascertained based on the second received signal.

Description

[0029] The invention will now be explained in greater detail based on the appended drawing, the figures of which show as follows:

[0030] FIG. 1 a schematic view of a vibronic sensor according to the state of the art,

[0031] FIG. 2 two possible embodiments known per se in the state of the art for a sensor unit suitable for performing the method of the invention, and

[0032] FIG. 3 a view of a possible embodiment of the method of the invention.

[0033] In the figures, equal elements are provided with equal reference characters.

[0034] Without intending to limit the general applicability of the invention, the following description concerns the case, in which a vibronic sensor 1 is used for performing the method of the invention.

[0035] FIG. 1 shows a vibronic sensor 1 having a sensor unit 2. The sensor has a mechanically oscillatable unit 4 in the form of an oscillatory fork, which is partially immersed in a medium M located in a container 3. The oscillatable unit 4 is excited by means of the exciter/receiving unit 5, such that the oscillatable unit 4 executes mechanical oscillations, and can be, for example, a piezoelectric stack- or bimorph drive. Other vibronic sensors use, for example, electromagnetic driving/receiving units 5. It is possible to use a single driving/receiving unit 5, which serves both for exciting the mechanical oscillations as well as also for their detection. Likewise, it is an option to implement a separate driving unit and a separate receiving unit. FIG. 1 shows, furthermore, an electronics unit 6, by means of which signal registration,—evaluation and/or—feeding occurs.

[0036] Shown in FIG. 2a, by way of example, are two different sensor units 2, which are especially suitable for performing a method of the invention. The mechanically oscillatable unit 4 includes, applied on a base 8, two oscillatory elements 9a,9b, which are also referred to as fork tines. Optionally, moreover, in each case, a paddle (not shown) can be formed at the ends of the two oscillatory elements 9a,9b. Provided in each of the two oscillatory elements 9a,9b is, in each case, an, especially pocket-like, hollow space 10a, 10b, in which, in each case, at least one piezoelectric element 11a, 11b of the driving/receiving unit 5 is arranged. Preferably, the piezoelectric elements 11a and 11b are cast within the hollow spaces 10a and 10b. The hollow spaces 10a, 10b can, in such case, be so created that the two piezoelectric elements 11a, 11b are located completely or partially in the region of the two oscillatory elements 9a, 9b. Such an arrangement as well as similar arrangements are described at length in DE102012100728A1.

[0037] Another example of a possible embodiment of a sensor unit 2 is shown in FIG. 2b. The mechanically oscillatable unit 4 in such case includes two parallel, rod shaped, oscillatory elements 9a, 9b, which are mounted on a disc shaped element 12 and which can be excited separately from one another to execute mechanical oscillations, and in the case of which the oscillations can likewise be received and evaluated separately from one another. The two oscillatory elements 9a and 9b have, in each case, a hollow space 10a and 10b, into which, in each case, at least one piezoelectric element 11a, 11b is arranged in the region facing the disc shaped element 12. Regarding the embodiment of FIG. 2b reference is made, in turn, furthermore, to German patent application No. 102017130527.0, which was unpublished as of the earliest filing date of this application.

[0038] As shown schematically in FIG. 2b, according to the invention, the sensor unit 2 is, on the one hand, supplied with an excitation signal E, in such a manner that the oscillatable unit 4 is excited such that mechanical oscillations are executed. The oscillations are produced, in such case, by means the two piezoelectric elements 11a and 11b. The two piezoelectric elements can be supplied with the same excitation signal E or the first oscillatory element 11a can be supplied with a first excitation signal E.sub.1 and the second oscillatory element 11b with a second excitation signal E.sub.2. Likewise, an option is that a first received signal R.sub.E is received based on the mechanical oscillations, or that separate received signals R.sub.E1, R.sub.E2 are received from each of the oscillatory elements 9a,9b.

[0039] Moreover, transmitted from the first piezoelectric element 11a is a transmitted signal S, which is received by the second piezoelectric element 11b in the form of a second received signal R.sub.S. Since the two piezoelectric elements 11a and 11b are arranged at least in the region of the oscillatory elements 9a and 9b, the transmitted signal S passes through the medium M when the sensor unit 2 is in contact with the medium M and is correspondingly influenced by the properties of the medium M. Preferably, the transmitted signal S is an, especially pulsed, ultrasonic signal, especially at least one ultrasonic pulse. Likewise, it is, however, also an option that the transmitted signal S from the first piezoelectric element 11a is transmitted in the region of the first oscillatory element 9a and reflected on the second oscillatory element 9b. In such case, the second received signal R.sub.S is received by the first piezoelectric element 11a. The transmitted signal S passes, in this case, twice through the medium M, this leading to a doubling of a travel time τ of the transmitted signal S and an increasing of the accuracy of measurement with reference to the determining of the velocity of sound.

[0040] The first R.sub.E and second R.sub.S received signals result from different measuring methods and can be evaluated independently of one another relative to different process variables P.sub.1 and P.sub.2, in the present case, the density ρ and the velocity of sound v.

[0041] An embodiment for the method of the invention is, finally, shown by way of example in FIG. 3.

[0042] FIG. 3a shows the density ρ and FIG. 3b the velocity of sound v of maltose and dextrin in a mash at different temperatures T, in each case, as a function of concentration C. The density ρ of the mash is a measure for the total concentration of maltose and dextrin in the mash. The density ρ is, however, independent of the degree of conversion. This does not hold, however, for the velocity of sound v. Here, there is a clear dependence on the ratio of maltose and dextrin.

[0043] Furthermore, the density ρ and the velocity of sound v are temperature dependent. An additional determining of the temperature T of the mash is accordingly advantageous.

[0044] The density ρ in the case of application of a vibronic sensor 1 shown in FIG. 2 can be determined, for example, based on the following formula:

[00001]$\rho =\frac{1}{S}.Math.\left[{\left(\frac{F_0}{F_{\mathrm{Med}}}\right)}^2-1\right]$

[0045] In such case, F.sub.Med is the oscillation frequency of the oscillatable unit 4 in the medium M, F.sub.0 is the reference frequency of the oscillatable unit 4 in vacuum, or in air, and S describes the sensitivity of the sensor unit 2. The oscillation frequency of the oscillatable unit 4 in the medium M, F.sub.Med, can be directly ascertained based on the first received signal R.sub.E.

[0046] The velocity of sound v of the medium M can, in turn, be ascertained from the separation L between the first 11a and second 11b piezoelectric elements (which serve as transmitting unit and receiving unit) and the travel time τ of the transmitted signal S from the first 11a to the second piezoelectric element 11b, according to the following formula:

[00002]$v=\frac{L}{\tau }$

[0047] For executing the embodiment of the method of the invention shown here by way of example, the total concentration of maltose and dextrin in the mash is ascertained based on the density ρ and the temperature T. Then, a value for the velocity of sound is determined and compared with the characteristic lines shown in FIG. 3c. The characteristic lines show here, by way of example, the velocity of sound v in the mash as a function of the degree of transformation U, thus, of the ratio of maltose and dextrin in the mash for a Plato-concentration of 12° P. The characteristic line, which is taken into consideration for the comparison, is, thus, selected as a function of total concentration and temperature.

LIST OF REFERENCE CHARACTERS

[0048] 1 vibronic sensor [0049] 2 sensor unit [0050] 3 container [0051] 4 oscillatable unit [0052] 5 driving/receiving unit [0053] 6 electronics unit [0054] 8 base [0055] 9a, 9b oscillatory elements [0056] 10a, 10b hollow spaces [0057] 11a, 11b piezoelectric elements [0058] 12 disc shaped element [0059] M medium [0060] P.sub.1-P.sub.2 process variables [0061] E excitation signal [0062] S transmitted signal [0063] R.sub.E first received signal [0064] R.sub.S second received signal [0065] ΔΦ predeterminable phase shift [0066] ρ density of the medium [0067] v velocity of sound [0068] τ travel time [0069] T temperature