Method for determining a setting time and / or an actual degree of hydration of an exothermically setting mass and method for providing a target degree of hydration of an exothermically setting mass and section of a production line for products comprising the setting mass

Abstract

The invention relates to a method for determining a setting time and / or an actual degree of hydration of an exothermically setting mass (4) (hereinafter: setting mass (4)), in particular a gypsum mass, - wherein the settable mass (4) is conveyed in a conveying direction (F) along a setting section (D) and - along the setting section (D) at at least a plurality of locations (i) discrete surface temperatures (T b,i ) of the setting mass (4) and at least one point (j) an ambient temperature (T amb ; T amp,j ), in particular above the setting mass (4), - using the discrete, measured surface temperatures (T b,i ) and the at least one ambient temperature (T amb , T amb ,j) discrete corrected plate temperatures (T corr,i ) and - a sigmoid function to the discrete corrected plate temperatures (T corr,i ) which shows a temporal temperature profile T corr (t) or a distance-related temperature curve T corr (d) represents, and - using characteristic parameters of the fitted sigmoid function, the setting time (t A ) and / or the degree of hydration of the settable mass (4) is determined at at least one position (P) of the setting section (D). Furthermore, the invention relates to a method for providing a desired degree of hydration of an exothermically setting mass at a predetermined position (P) of a setting section (D) of a production line using the determination method and to a section of a production line for carrying out the method.

Description

The invention relates to a method for determining a setting time and / or an ACTUAL hydration degree of an exothermically settable mass, and to a method for providing a TARGET hydration degree of an exothermically settable mass and section of a production line for products having settable masses.To determine a certain degree of hydration of an exothermically settable mass, it is known to determine the setting behavior of the exothermically settable mass by means of an AT-line measurement. In the context of such an AT-line measurement, a sample of the exothermically resistant composition is observed away from a production line in a heat-insulated container with regard to its temperature profile during the treatment. The temperature curve over the time of the exothermic setting of the sample is recorded. A hydration curve determined in this way is used to infer the corresponding degree of hydration of the settable mass on a production line. An inflection point of a characteristically arising sigmoid curve of the temperature profile represents the so-called setting time t A of the exothermically settable compound. Using the temperature-time profile determined in this way and taking into account a known conveying speed v of a conveying device of a production line, a specific degree of hydration is deduced at a specific position P along a setting section D.This method of AT-line measurement is time-consuming and cumbersome to carry out. In addition, the hydration curves obtained in a laboratory environment are not always transferable with sufficient accuracy to a real environment of a production line for products of an exothermically settable compound. Environmental influences along the production line are completely ignored.U.S. Pat. No. 10,677,698 B2 discloses an online measurement of a degree of hydration of a slurry of an exothermically settable mass. In this case, at selected points along the production line, at least at a selected point of the production line, a pressing force for a predetermined pressing depth is measured by means of a pressing body and a degree of hydration of the settable compound at the point of the pressing is deduced therefrom as a function of the penetration depth. Although this solution provides online measurement, this solution also causes unwanted impressions for the purpose of testing at the sites to be tested, which may result in undesirable visual appearance in the final product.It is therefore an object of the invention to specify a method, improved compared to the prior art, for determining a setting time and / or an ACTUAL degree of hydration of an exothermically settable compound, which operates in contactless fashion, i.e. without mechanical contact with the settable compound, and can also be realized within the scope of an IN-line measurement. In addition, varying environmental influences, in particular varying environmental temperatures along the production line, are to be taken into account with the method according to the invention, such that the ascertained degree of hydration or the ascertained course of the setting can be ascertained independently of, in particular, external temperature-environmental conditions. As a result, the method according to the invention is intended to help reduce the personal care outlay of a production line for products from a settable compound.A further object of the invention is to provide a desired degree of hydration of the exothermically settable compound within a specific tolerance band at a specific position P along a setting section D, in particular with a higher accuracy than the prior art.It is a further object of the invention to provide a section of a production line for products of exothermically settable materials, with which the processes according to the invention can be carried out.With regard to the determination of the setting time t A and / or the ACTUAL hydration degree, the object according to the invention is achieved by a method for determining a setting time t A and / or an ACTUAL hydration degree of an exothermically settable compound (hereinafter: settable compound), in particular a gypsum compound, wherein the settable compound is conveyed in a conveying direction F along a setting section D and discrete surface temperatures T b,i of the settable compound and at least one ambient temperature T amb; T amb,j, in particular above the settable compound are detected along the setting section D at at least a plurality of points i, wherein using the discrete, curable compound, the specific temperature T being calculated as a function of the specific temperature T T in particular above the settable compound, The setting time t A and / or the actual degree of hydration of the settable mass is determined on the basis of characteristic parameters of the adjusted sigmoid function.The method specified above makes it possible to provide a contactless online determination method for an ACTUAL degree of hydration and / or a setting time taking into account present current ambient conditions in a production line, in particular ambient temperatures. By means of contactless measurement, no traces on the finished product resulting from a measurement can be detected. Due to the consideration of ambient temperatures, it is possible in particular to take account of time-of-day and or season-of-year ambient influences, so that the determination of the setting time and also the determination of the degree of hydration at a specific position P can be carried out with higher accuracy.In a particular embodiment of the method, a time coordinate t W or a route coordinate d W of an inflection point W of the sigmoid function is defined as a setting time t A or as a setting route d A.This measure makes in particular the results obtained with the method according to the invention well comparable to previous measured values and empirical values from comparable AT-line methods or other measurement methods from the prior art, which use the same definition for the setting time t A.These advantages can likewise be achieved if a time coordinate t W or a route coordinate d W of a point with maximum gradient of the sigmoid function is defined as a setting time t A or as a setting route d A.Advantageously, a ratio of a temporal temperature increase ΔT(t) at a time t to a total temperature increase ΔT corr,ges or a ratio of a stretch-related temperature increase ΔT corr( d) at the position P to a total temperature increase ΔT corr,ges is defined as an ACTUAL hydration level.This measure also increases the comparison of the results obtained according to the invention with measurement results from already known measurement methods.In order to reduce the complexity of the underlying calculations for determining the influences of the ambient influences, in particular the ambient temperatures, it is expedient that at least one, preferably all, assumptions listed below are made for the purpose of calculating the corrected plate temperature T corr,i in a simplified manner:no heat transport takes place from an interior of the settable compound to an environment U on the underside or to an environment U on edge sides of the settable compound,an ideal heat transport is present within the settable mass;a temperature curve T corr( t) over time is constant between two points i;a heat transfer coefficient k between the settable mass and the environment U does not depend on an ambient air temperature or an ambient air humidity.In order to be able to achieve a meaningful and meaningful approximation of a schwanne curve, an S curve or a so-called sigmoid function, it is expedient that the surface temperature T b,i and independently thereof the ambient temperature T amb,j is measured at at least 4 points, i.e. i,j is greater than or equal to 4, particularly preferably at 9 points (i,j=9), with the proviso that j≤i.In this case, the measurement accuracy along the setting distance D becomes higher as the number i,j increases. However, as the number of points i,j increases, i.e. the measurement points, the cost of the measurement devices and the calculation effort for the evaluation of the measurement results also increase. The skilled person will be able to determine an economically and technically viable number i,j as a function of the intended purpose. It should also be taken into account here that, in a simplest case, the ambient temperature T amb,j is measured at only a single point (j=1) of the setting section D. This can be particularly expedient if, on account of the present production conditions in the corresponding production hall, almost the same ambient temperatures along the setting section D can be assumed.According to a convenient calculation formula, the corrected plate temperature T corr,i is calculated as follows:• i is a location where the surface temperature T b,i is measured,• j is a location at which the ambient temperature T amb,j is measured,• m is a running variable representing an m-th location i,• m(j) is a location j that is locally closest to an m-th location i and that is assigned to the m-th location i,• T corr,i is the corrected plate temperature at the location i,• T b,i; is the measured surface temperature T b,i: at the location i• T b,m is the measured surface temperature at the m-th location i,• h is a thickness of the settable compound,• T amb,m( j) is the ambient temperature T amb,j, measured at a point j closest to the m-th point i, which is assigned to the m-th point i• Δt m is a time period required for a certain volume of the settable mass from an (m-1)-th location i to a subsequent m-th location i along the conveying direction F,• K is an experimentally determined correction factor, and• is an optional correction factor, which for further simplicity can also be assumed to be 1, which takes into account an instantaneous band speed v and a reference band speed v 0.With alternative embodiments listed below, it is possible to adapt the method according to the invention to different environmental constellations and accuracy requirements. In this case, it can be provided, for example, that the number of points j≥1, wherein in particular the number of points j is equal to the number of points i, i.e. that the ambient temperature T amb,j is measured at all points i, or alternatively that the number of points j is less than the number of points i, i.e. that the ambient temperature T amb,j is measured at fewer points j than there are points i.In the case where the ambient temperature T ampv,j is measured at fewer points j than the surface temperature T b,i at points i, the measured surface temperature T b,m of the m-th point i is correlated with that measured value of the ambient temperature T amb,m( j) in the given formula for the corrected surface temperature T corr,i the point j of which is spatially closest to the m-th point i. That is, T amb,,m( j) corresponds to the measurement value T amb,,j, which is spatially closest to the m-th location i.In particular for an improved repeatability of the method according to the invention and for an improved reproducibility of the results obtained thereby, it may be expedient for the correction factor K for a settable mass to be determined experimentally in the context of AT-line measurements.A correction factor K determined on a specific example of use has, for example, the value K≈1.5-2.5-10 -5 m / s depending on a plate thickness of 10 mm to 18 mm.The correction factor K for a settable mass can expediently be determined experimentally according to the formulak is a heat transfer coefficient of the settable mass to the environment U,p is a density of the settable mass, andc is a heat capacity of the settable mass.It is furthermore expedient that the temperature measurement of the surface temperatures T b,i for example by means of infrared thermometers, takes place in contactless fashion.In this way, in particular a temperature measurement of the product which is non-destructive, in particular free of damage, is ensured.The process according to the invention can be advantageously applied to exothermic setting compositions, for example one or more of the following listed setting compositions:cement compositions, e.g. Portland cements, sorel cementsgypsum compounds.With regard to the object of providing a TARGET degree of hydration, the object according to the invention is achieved by a method for providing a TARGET degree of hydration of an exothermically settable mass at a predetermined position P of a setting section of a production line, wherein the method according to one of claims 1 to 12 is used to determine the ACTUAL degree of hydration at the position P and wherein, if the ACTUAL degree of hydration of the settable mass at the position P deviates from the TARGET degree of hydration at the position P by more than a degree of hydration tolerance at the position P, a mass composition of the settable mass is adapted in such a way in an application device, in particular a mixer of the production line, until the actual degree of hydration at position P is within the tolerance of the degree of hydration at position P.With this method, it is possible in particular in a simple manner, using the results of the method according to the invention for determining an actual degree of hydration, to provide an online process procedure for the production of products from an exothermically curable composition. This is especially important for determining a degree of hydration upstream of a cutting device, since during a cutting process of a settable compound, the latter must already have a certain minimum degree of sensation, so that the cutting process can be carried out qualitatively in a perfect manner.It is expedient that the composition of matter is adjusted by increasing or reducing a proportion of a setting accelerator.The device-specific objects of the invention are achieved with a section of a production line for products having settable masses, in particular a setting section D of a production line for plate-shaped gypsum products, wherein the section extends between an application device for a slurry of the settable mass and a cutting device for separating an at least partially settable settable settable settable settable mass, and the settable mass is conveyable along the setting section D by means of a conveying device along the conveying direction F, wherein at least one temperature detection device is arranged along the setting section D at at least one plurality of points i, each of which is configured and designed, at least the surface temperature T b,i of the settable mass at the point i is measured and, in particular along the setting distance D, at least at one or more points j a temperature detection device is present, which is configured and designed to measure an ambient temperature T amb; T amb,j of an environment U of the settable mass.With such a configuration of a section of a production line, the methods according to the invention can be carried out in a simple and expedient manner. Such a section of a production line according to the invention is simple in construction and robust in handling.In order to realize specific requirements with regard to accuracy and or economy, it can be expedient for the number of digits i to be at least 4, in particular 9, and for the number of digits j to be at least 1, wherein in particular the number of digits i is equal to the number of digits j.In order to form a production line for producing gypsum board-shaped products, it is expedient for the application device to be a mixer of a production line for gypsum products and for the cutting device to be a cutting device for gypsum board-shaped products.In order to reduce the space requirement and to reduce the complexity of the construction of a production line according to the invention, it is expedient for the temperature detection devices to be designed and configured to measure both the surface temperature T b,i of the at least partially bound settable compound and the ambient temperature T amb,j at each point i.In order to increase or reduce the observation accuracy and or the course accuracy of certain segments of the connecting section, the temperature detection devices are expediently arranged uniformly distributed along the setting section D or they are arranged more closely spaced apart from one another or further away from one another along a segment of the setting section D in the conveying direction F in comparison with the remaining setting section D.For carrying out the methods according to the invention, it is particularly expedient that means are present for detecting a conveying speed v of the at least set settable compound.The invention is explained in more detail below by way of example with reference to the drawings. The following are shown: FIG. 1 : shows an overview of a production line according to the invention for plate-shaped gypsum products; FIG. 2 : schematically, a side view of a binding section D of a section of the production line according to the invention; FIG. 3 a : shows a diagram with surface temperature profiles along a setting section D without taking into account ambient temperature influences; FIG. 3 b : shows a diagram with surface temperature profiles along a setting section D taking into account ambient temperature influences; FIG. 4 : a flow chart which illustrates the method according to the invention for determining a setting time and / or an ACTUAL hydration degree; FIG. 5 : shows a flow chart which illustrates the method according to the invention for providing a TARGET degree of hydration at a position P of the setting section D. FIG. 6 : shows an exemplary profile of a sigmoid function which was obtained from 9 temperature measurement values T, by way of example.FIG. 1 shows, by way of example, a production line 1 for producing a product from an exothermically resistant compound 4 using the example of a production line 1 for gypsum board panels 2, which are board-shaped gypsum products 2. An application device 3 provides a composition of the settable compound 4 and applies it to a first cardboard layer 5. Immediately after the application device 3, which is designed, for example, as a mixer, the settable mass 4 is present as a slurry with a very low degree of hydration, for example less than 4%. A distance between the mixer / application device 3 and the cutting device 6 downstream of the application device 3 in a conveying direction F is defined as the setting distance D in the example shown. Downstream of the cutting device 6 in the conveying direction F, a turning station 7 and a dryer 8 are provided. At the end of the production line 1 a packaging station, for example a palletizer 9, is provided. A conveying device 11 (compare FIG. 2 ) is provided, with which at least the settable mass 4 is conveyed by the application device 3 along the setting distance D in the conveying direction F.Along the binding path D, a plurality, in particular i=4 or more than 4, further in particular i=9, of temperature detection devices 10 is provided. The temperature detection devices 10 are configured and designed in such a way that they can detect, without contact, a surface temperature T b,i of the settable mass 4 itself or of a product / intermediate product having the settable mass 4 produced along the settable distance D. The surface temperature T b,i is detected at at least 4 points i, in particular at more than 4 points i, further in particular at 9 points i. Infrared thermometers can be used, for example, as suitable temperature detection devices 10.At least one of the temperature detection devices 10 is configured and designed in such a way that it is also capable of detecting an ambient temperature T amb, T amp,j in an environment U around the settable mass 4, in particular in an environment U above the settable mass. Alternatively, a separate temperature detection device can of course also be provided for measuring the ambient temperature T amb, T amb,i. The ambient temperature T amb, T amb,j is recorded at at least one point j, in particular at all points j=i. An area vertically above the settable compound 4 is defined as environment U.With the surface temperatures T b,i detected at the points i, a corrected plate temperature T corr,i at the points i is calculated together with associated ambient temperatures T amb, T amb,m( j) according to the following formula:i is a point at which the surface temperature T b,i is measured,j is a point at which the ambient temperature T amb,j is measured,m is a running variable representing an m-th location i,m(j) is a location j which is locally closest to an m-th location i and which is assigned to the m-th location i,T corr,i is the corrected plate temperature at the point i,T b,i is the measured surface temperature at the point i,T b,m is the measured surface temperature at the m-th point i,h is a thickness of the settable compound 4,T amb,m( j) the ambient temperature T amb,j, measured at a point j closest to the m-th point i, in particular measured above the settable mass 4 which is assigned to the m-th point i,Δt m a time period required for a certain volume of the settable mass 4 from the (m-1)-th location i to the subsequent m-th location i along the conveying direction (FK is an experimentally determined correction factor; andan optional correction factor which, for further simplification, can also be assumed to be 1, takes into account an instantaneous band velocity v and a reference band velocity v 0.A sigmoid function is approximated to the corrected discrete plate temperatures T corr,i, which are calculated according to the above formula and are based on the surface temperatures T b,i or times t measured along the binding section D after a certain period of time after application of the slurry of the settable mass 4, using an approximation algorithm. This approximation is carried out using conventional methods, for example the least squares method. With this sigmoid function, a continuous, no longer discrete temperature curve T corr( t) is produced from the application of the slurry of the settable compound 4 or a continuous, no longer discrete, stretch-related temperature curve T corr( d) is produced from the beginning of the setting stretch D.FIG. 2 shows a section 20 according to the invention of a production line 1, wherein the section 20 extends between the application device 3, for example the mixer and the cutting device 6. By means of the front device 11, the settable mass 4 can be conveyed in the conveying direction F at a belt speed v. Due to the belt speed v, a relative movement of the surface of the settable mass 4 with respect to the ambient air is generated with the same magnitude, which ensures a changed heat transfer between the settable mass and the environment depending on the magnitude of the belt speed v. This produces a cooling effect.According to the invention, therefore, the cooling effect of the heat transfer between the surface of the settable mass 4 and the environment U is taken into account. The measured temperatures T b,i are corrected according to the invention in such a way that the heat transfer at the top side of the settable mass 4 to the environment U is input into the calculation of the corrected temperature values. Such a heat transfer between the upper side of the settable mass 4 and the environment U is expediently determined for a strip reference speed v 0. If, in a specific application, the strip speed v is increased or reduced compared to the strip reference speed v 0 then the correspondingly increased or reduced heat transfer can be adequately taken into account by a factor (v / v 0)0,8. For only minor deviations of the tape speed v from the tape reference speed v 0 this factor can also be assumed approximately with the value 1.In the schematic illustration of an embodiment of the section 20 according to the invention, the nine pieces of temperature detection devices 10 are uniformly spaced along the binding section D. Of course, it is also possible to increase the number of temperature detection devices 10 along the binding path D in order to increase the detection accuracy or to reduce it in the case of, for example, less stringent requirements for the detection accuracy. Alternatively, the distance between two successive temperature detection devices 10 along the setting distance D can also be non-uniform, as an example shown. For example, in a certain range in which a higher detection accuracy is required, a higher number of temperature detection devices 10 per subsection of the binding section D can be used.FIG. 3 ashows a diagram in which temperature profiles of the measured surface temperatures T b,i of a specific settable mass 4 in different runs at different times (15 December 2022, afternoon and 16 December 2022, beforenoon) are shown without consideration of an ambient temperature T amb, T amb,i and without correction plate temperature T corr,i resulting therefrom. A temperature profile (16 December 2022, 9:30) deviates considerably from the remaining 3 temperature profiles and would thus provide a false statement about the ACTUAL degree of hydration. In the legend to FIG. 3A, meter data are respectively placed in brackets in the description of the measuring point symbols at the end, these meter data being 244 m, 259 m, 208 m and 246 m in the examples. These distance information items are distances from the application device in meters, which is the distance of the inflection point W from the mixer 3 determined from the parallel / simultaneously performed measurements by means of the AT-LINE TRS measurement, i.e. the determined distance of the inflection point W from the application device.FIG. 3 b shows, for 2 different settable masses 4 (FHB and Habito), in each case a measured temperature profile T b,i and a stretch-related temperature profile T corr( d) corrected according to the invention as a function of the corrected plate temperatures T corr,i. The corrected temperature profiles T corr( d) run throughout above the corresponding uncorrected temperature profiles T b,i. A time period t A is determined on the basis of the position of an inflection point W at which the maximum slope of the approximated sigmoid function, which is approximated to the discrete points of the corrected plate temperatures T corr,i with the distance from the application device and a known conveying speed in the conveying direction F. The time t required for traveling the distance from a point of application of the settable compound 4 to the inflection point W is defined as the setting time t A.In the following, it is explained in more detail by way of example with reference to FIG. 6 how an ACTUAL degree of hydration can be determined at a specific point P.Knowing the approximated sigmoid curve T corr( t), a total temperature rise ΔT corr,ges is determined. It is assumed that after reaching the total temperature rise ΔT corr,ges a degree of hydration of 100% of the mass 4 is reached. In order to now determine the ACTUAL degree of hydration there at any desired, but determined position P, the corrected temperature ΔT corr( P) corresponding to the position P is determined on the basis of the sigmoid curve. A temperature rise over time ΔT corr( t) results from the difference between the corrected temperature ΔT corr( P) corresponding to the position P and a corrected initial temperature T corr, Start, which is advantageously determined, for example, at the point i=1 or is taken, for example read, from the sigmoid curve at a point before the point i=1.A ratio of the temperature rise ΔT corr( t) to the position P over time to the total temperature rise ΔT corr,ges is defined as the ACTUAL hydration degree at the position P. If an actual degree of hydration too far away from a desired degree of DESIRED hydration is now present at position P, then by influencing the composition of mass 4, for example by adding or reducing a hydration accelerator, the ACTUAL degree of hydration at point P can be approximated to the desired degree of DESIRED hydration there.An application that is suitable for this purpose is, for example, to set an actual degree of hydration sufficient for the cutting operation there at a point P C, at which the cutting device 6 is located.Thus, the invention makes it possible to provide information continuously online at which position P which degree of hydration is currently present. An AT-LINE measurement to be carried out in parallel with this is no longer required.The method according to the invention for determining an actual degree of hydration at a position P and or the setting time t A according to the invention is described below by way of example with reference to steps S 101 to S 105.In step S 101, care is first taken to ensure that a settable mass 4 is conveyed in a conveying direction F of a setting section D. This takes place, for example, with a tape speed v, which can be greater than, equal to or less than a tape reference speed v 0.In step S 102, a plurality of discrete surface temperatures T b,i of the settable compound 4 along the setting distance D and at least one ambient temperature T amb; T amb,j are measured. This is preferably carried out in contactless fashion, for example using infrared thermometers.Discrete, corrected plate temperatures T corr,i are calculated from the discrete, measured surface temperatures T b,i and the at least one ambient temperature T amb; T amb,j wherein these corrected plate temperatures T corr,i take into account, in particular, a heat transfer between an upper side of the settable mass 4 and an upper side environment U above the settable mass 4 (step S 103).With the discrete, calculated, corrected plate temperatures T corr,i it is possible to adapt a sigmoid function which represents a temporal temperature profile T corr( t) or a route-related temperature profile T con( d) (step S 104).In a step S 105, the setting time t A and / or the ACTUAL degree of hydration at at least one position P is determined on the basis of characteristic parameters of the adapted sigmoid function. For determining the setting time, a characteristic parameter of the sigmoid function is suitable, for example, in the form of an inflection point W. The time belonging to the inflection point W from the application of the settable compound 4 until the inflection point W is reached is expediently defined as setting time t A. An ACTUAL degree of hydration can be defined, for example, such that a temperature change ΔT corr( d) up to a specific position P at a distance from the application region of the settable mass 4 of the sigmoid function or a temperature change ΔT corr( t) up to a specific time t since the application of the settable mass 4 of the adapted sigmoid function is related to a total temperature change ΔT corr,ges of the settable mass 4 over the entire distance to be found D. The percentage value obtained therefrom is defined as the ACTUAL degree of hydration in percent.In the following, the method according to the invention for providing a TARGET degree of hydration of an exothermically curable mass 4 at a predetermined position P of a curing section D is explained by way of example with reference to FIG. 5.First, in a step S 201, a determination of the ACTUAL degree of hydration at a position P is determined using the method according to the invention for determining an ACTUAL degree of hydration explained above.Subsequently, in a step S 202, a check is made as to whether the ACTUAL degree of hydration of the settable mass 4 at the position P deviates from the TARGET degree of hydration at the position P by more than a predetermined degree of hydration tolerance at the position P. If this is the case, an adjustment of a composition of the settable compound 4 is carried out in a step S 203. This is done by increasing or reducing an addition of a setting accelerator into the slurry of the settable composition 4.If the actual degree of hydration of the settable mass 4 at position P is within the tolerance of the degree of hydration at this position P, no adjustment of the mass composition has to be made by changing the addition of setting accelerator.The above-described procedure can then be carried out again after a predetermined time window, which can be in the minute range or in the hour range, or continuously in order to ensure continuous monitoring of the ACTUAL degree of hydration at the position P. The position P is in particular a position at or just before the cutting device 6, since special compliance with a minimum ACTUAL degree of hydration is necessary at this point. Cutting of, for example, gypsum board boards usually requires a minimum ACTUAL degree of hydration of greater than or equal to 50% at the cutting device 6.List of reference characters1 Production line 2 plate-shaped gypsum products, gypsum board 3 application device, mixer 4 settable compound 5 first board layer 6 cutting device 7 turning station 8 dryer 9 palletizer 10 temperature detection device 11 conveying device 20 section F conveying direction D setting section T corr( t) temporal temperature profile T corr( d) section-related temperature profile t A setting time d A setting section T b,i measured surface temperature at the point i P position T amb; T amb,j ambient temperature t W time coordinate of the inflection point d W route coordinate of the inflection point W inflection point ΔT corr( d), route-related temperature rise ΔT corr( t) temporal temperature rise ΔT corr,ges total temperature rise i, location at which the surface temperature T b,i is measured j location at which the ambient temperature T amb,j is measured m running variable representing an m-th location i m(j) location j, the plate temperature at the location i h thickness K correction factor v band velocity v 0 reference band velocity ρ density of the settable mass c heat capacity of the settable masses Δt m time period, which is locally closest to an mth location i and is assigned to the mth location i k heat transfer coefficient of the settable mass to the environment UT corr,i, which requires a certain volume of the settable mass from an (m-1)th location i to a subsequent mth location i along the conveying direction F. U environment t time point P C position of the cutting device 6 S 101 step S 102 step S 103 step S 104 step S 105 step S 201 step S 202 step S 203 stepReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedU.S. Pat. No. 10,677,698 B2

[0004]

Claims

Method for determining a setting time and / or an ACTUAL degree of hydration of an exothermically settable mass (4) (in the following: settable mass (4)), in particular a gypsum mass, - wherein the settable mass (4) is conveyed in a conveying direction (F) along a setting section (D) and - discrete surface temperatures (T b,i) of the settable mass (4) are detected along the setting section (D) at at least a plurality of points (i) and an ambient temperature (T amb; T amb,j), in particular above the settable mass (4) is detected at at at least one point (j), - wherein using the discrete, curable mass (4), Surface temperatures (T b,i) and the at least one ambient temperature (T amb, T amb,j) discrete corrected plate temperatures (T corr,i) are calculated and - a sigmoid function is adapted to the discrete corrected plate temperatures (T corr,i) which represents a time-based temperature profile T corr( t) or a stretch-related temperature profile T corr( d), and - the setting time (t A) and / or the degree of hydration of the settable compound (4) is determined at at least one position (P) of the setting stretch (D) on the basis of characteristic parameters of the adapted sigmoid function.Method according to Claim 1, characterized in that a time coordinate (t W) or a route coordinate (d W) of an inflection point (W) of the sigmoid function is defined as a setting time (t A) or as a setting route (d A).Method according to Claim 1, characterized in that a time coordinate (t W) or a route coordinate (d W) of a point with maximum gradient of the sigmoid function is defined as a setting time (t A) or as a setting route (d A).Method according to claim 1, characterized in that a ratio of a temporal temperature rise (ΔT corr( t)) at a time (t) to a total temperature rise (ΔT ges) or a ratio of a stretch-related temperature rise (ΔT corr( d)) at the position (P) to a total temperature rise (ΔT corr,ges) is defined as an ACTUAL hydration degree.Method according to one of Claims 1 to 4, characterized in that, for the purpose of calculating the corrected plate temperature (T corr,i) at least one, preferably all, assumptions listed below are made in a simplified manner: - there is no heat transport from an interior of the settable mass (4) to an environment (U) on the underside or to an environment (U) on edge sides of the settable mass (4), - there is an ideal heat transport within the settable mass (4); - a temporal temperature profile T corr( t) is constant between two points (i); - a heat transfer coefficient k between the settable mass (4) and the environment (U) does not depend on an ambient air temperature or an ambient air humidity.Method according to one of the preceding claims, characterized in that the surface temperature (T b,i) particularly preferably at 9 points (i, j), the surface temperature (T b,i) and the ambient temperature (T amb,j) are measured at at least 4 points (i).Method according to any of the preceding claims, characterized in that the corrected plate temperature (T corr,i) is calculated as indicated below: wherein - i is a location where the surface temperature T b,i is measured, - j is a location where the ambient temperature T amb,j is measured, - m is a running variable representing an m-th location (i), - m(j) is a location (j) that is locally closest to an m-th location (i) and that is associated with the m-th location (i), - T corr,i is the corrected plate temperature at the location (i), - T b,i is the measured surface temperature at the location (i), T b,m is the measured surface temperature at the m-th location (i), - h is a thickness of the settable mass (4), - T amb,m( j) is the ambient temperature T amb,j, measured at a location (j) closest to the m-th location (i), in particular measured above the settable mass (4) which is assigned to the m-th location (i), - Δt m is a time period, which requires a specific volume of the settable mass (4) from the (m-1)th location (i) to the subsequent mth location (i) along the conveying direction (F)-K is an experimentally determined correction factor and-(v v 0) 0.8 is an optional correction factor which, for further simplification, can also be assumed with the value 1, takes into account a current belt speed v and a reference belt speed v 0.Method according to claim 7, characterised in that the number of points j≥1, wherein in particular the number of points (j) is equal to the number of points (i), i.e. the ambient temperature (T amb,j) is measured at all points (i), or alternatively the number of points (j) is smaller than the number of points (i), i.e. the ambient temperature (T amb,j) is measured at fewer points (j) than there are points (i), and the corrected surface temperature (T corr,i) the measured surface temperature (T b,m) of the m-th location (i) correlates with that measurement value of the ambient temperature (T amb,m( j)) whose location (j) is spatially closest to the m-th location (i).Method according to one of the preceding claims, characterized in that the correction factor (K) for a settable mass (4) is determined experimentally in the context of AT-line measurements.Method according to one of the preceding claims, characterized in that the correction factor K for a settable mass (4) is determined experimentally according to the formula K = k ρ * c wherein k is a heat transfer coefficient of the settable mass (4) to the environment (U), in particular to the environment U above the settable mass (4), ρ is a density of the settable mass (4) and c is a heat capacity of the settable mass (4).Method according to one of the preceding claims, characterized in that the temperature measurement of the surface temperatures (T b,i) is carried out in a contactless manner.Method according to one of the preceding claims, characterized in that the method is applied to exothermically settable compositions (4), e.g. one or more of the settable compositions (4) listed below: - cement compositions, e.g. Portland cements, Sorel cements - gypsum compositions.Method for providing a TARGET degree of hydration of an exothermically settable mass (4) at a predetermined position (P) of a setting section (D) ich of a production line (1), wherein the ACTUAL degree of hydration at the position (P) is determined by means of the method according to one of claims 1 to 12 and wherein, if the ACTUAL degree of hydration of the settable mass (4) at the position (P) deviates from the TARGET degree of hydration at the position (P) by more than a degree of hydration tolerance at the position (P), a mass composition of the settable mass (4) is adjusted in such a way in an application device (3), in particular a mixer (3) of the production line (1), until the actual degree of hydration at position (P) is within the tolerance of the degree of hydration at position (P).Method according to claim 13, characterised in that the composition of the composition is adjusted by increasing or reducing a proportion of a setting accelerator.Section of a production line for products, having settable masses (4), in particular a setting section (D) of a production line (1) for plate-shaped gypsum products, for carrying out the method according to one of Claims 1 to 12 and for carrying out the method according to one of Claims 13 and 14, wherein the section extends between an application device (3) for a melt of the settable mass (4) and a cutting device (6) for separating an at least partially settable settable settable settable settable settable mass (4) and the settable mass (4) can be conveyed along the setting section (D) by means of a conveying device (11) along the conveying direction (F), characterized in that at least one temperature detection device (10) each is arranged along the setting section (D) at at least one plurality of points (i), which are configured and designed, at least the surface temperature (T b,i) of the settable mass (4) at the point (i) and, in particular along the setting distance D, at least at one or more points (j), a temperature detection device (10) is present, which is configured and designed to measure an ambient temperature (T amb; T amb,j) of an environment (U), in particular above the settable mass (4).Section of a production line according to Claim 15, characterized in that the number of points (i) is at least 4, in particular is 9, and the number of points (j) is at least 1, the number of points (i) in particular being equal to the number of points (j).Section of a production line according to claim 15 or 16, characterised in that the application device (3) is a mixer (3) of a production line (1) for gypsum products and the cutting device (6) is a cutting device (6) for plate-shaped gypsum products (2).Section of a production line according to one of Claims 15 to 17, characterized in that the temperature detection devices (10) are designed and configured to measure both the surface temperature (T b,i) of the at least partially bound settable compound (4) and the ambient temperature (T amb,j) at each point (i).Section of a production line according to one of Claims 15 to 18, characterized in that the temperature detection devices (10) are arranged uniformly distributed along the setting section (D) or are arranged more closely spaced apart from one another or further away from one another along a subsection of the setting section (D) in the conveying direction (F) in comparison with the remaining setting section (D).Section of a production line according to one of Claims 15 to 19, characterized in that means are provided for detecting a conveying speed (v) of the at least bound settable mass (4).

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