INSTALLATION FOR CEMENT PRODUCTION, DEVICE FOR MEASURING ACOUSTIC TEMPERATURE AND ITS METHOD OF OPERATION

Abstract

INSTALLATION FOR CEMENT PRODUCTION, DEVICE FOR MEASURING ACOUSTIC TEMPERATURE AND ITS METHOD OF OPERATION. The present invention relates to a device (1) for at least one acoustic temperature measurement in a gaseous medium (M) passing through a medium channel (110) by means of time-operation measurement of an acoustic pulse (AP) flowing through the gaseous medium (M) from at least one first transmitter arrangement (TA1) to at least one first receiver arrangement (RA1), the first transmitter arrangement (TA1) comprising a sound pulse generator (2) to generate the acoustic pulse (AP), which is connected by a first acoustic channel (3) to a transmitter (4) that transmits the acoustic pulse (AP) into the medium (M), the first acoustic channel (3) being of acoustically dispersive design, and,the first receiver arrangement (RA1) comprising a receiver (5) for receiving the acoustic pulse (AP) after it has passed through the medium (M) and for transmitting it through a second acoustic channel (6) to a first microphone (7), preferably a piezoelectric microphone (7), for detecting the acoustic pulse (AP), the first acoustic channel (3) being curved towards the sound pulse generator (2) in such a way that the radiant heat from the medium (M) on the sound pulse generator (2) is at least greatly reduced, wherein at least the transmitter (4) comprises, in the first acoustic channel (3) on its side (41) facing the medium (M) to be measured, an interference element (42) that retroreflects a part (RI) of the acoustic pulse (AP) into the first acoustic channel (3) of the first transmitter arrangement (TA1), wherein a second microphone (8), preferably arranged on the side (43) of the transmitter (4) facing the sound pulse generator (2),is arranged for detection of the retroreflected part (RI) of the acoustic pulse (AP), the device (1) further comprising a pulse discriminator (9) designed to determine the arrival times (AT) of the recorded acoustic pulses (AP) in a suitable manner and to transmit them to an evaluation unit (10) designed to determine the temperature of the medium (M) from the operating time of the acoustic pulse (AP) from the transmitter (4) to the receiver (5), taking into account the arrival times (AT) determined by the pulse discriminator and the acoustic pulses (RI, AI) detected by the first and second microphones (7, 8).

Description

1 / 26 DESCRIPTIVE REPORT “CEMENT PRODUCTION PLANT, DEVICE FOR MEASURING ACOUSTIC TEMPERATURE AND ITS METHOD OF OPERATION” FIELD OF TECHNIQUE

[001] The invention relates to a device for acoustic temperature measurements, to an installation for cement production or other production using or containing hot gases comprising such a device, and to a method for operating such a device. BACKGROUND OF THE TECHNIQUE

[002] Cement is the most important aggregate for the production of concrete, by far the most common building material today. Cement production is based on several chemical reactions at very high temperatures. Various measurement techniques are used today for process optimization and for monitoring the operating conditions and emission behavior of plants. Chemical analysis of the process gas for its composition at individual stages of the manufacturing process provides very important information about the combustion process and fuel use, among other things, in order to optimize energy use, to improve or maintain the required product quality, to extend the service life and availability of plants, and to reduce maintenance costs. In addition to these aspects, environmental protection plays a central role in cement production.In concrete terms, this means that the cement industry and developers and manufacturers of process analytics for the cement industry must address the problems of (a) reducing CO2 emissions, (b) reducing energy consumption in the operation of rotary kilns, and (c) stabilizing process control and regulation, among other things, during the use of primary or secondary fuels. This requires high measurement reliability, accuracy, and repeatability of process parameters during the cement manufacturing process. One of the most important process parameters is the gas temperature in cement kilns and related equipment, as such temperatures can rise to... Petition 870220048584, dated 02 / 06 / 2022, pp. 103 / 145 2 / 26 Temperatures of up to 1,800°C, depending on the location within the cement kiln, place very high demands on the temperature stability and accuracy of the measuring equipment, particularly since, for cement kilns, this measurement must be reliably achieved in environments typically laden with dust and dirt. Until now, temperature measurement has generally been performed using thermocouples driven into the gas flow of the medium to be measured. In order to perform the measurement, the thermocouples must be brought into thermal equilibrium with the gas flow. This is only possible if the gas flow is not too turbulent and there are no heat sources or heat sinks in the vicinity that would distort the measurement result due to thermal radiation. Due to the high exposure to abrasive dust, thermocouples must be used in thick steel tubes or shielded with ceramics.As a result, the reaction time of these temperature measurement points drops considerably, ranging from a few minutes to a quarter of an hour. Since a significant gas temperature does not need to be measured near the wall, but deeper within the medium, these shielded tubes need to be driven far into the continuous gas flow. Thus, they wear out quickly and must be replaced within weeks. Furthermore, temperature measurement using thermocouples is a point measurement, whereas, in most cases of the large machinery used in cement production, the average temperature along a path or volume is required.

[003] Acoustic sound pyrometry has been used for a long time in the power plant sector, according to which an artificially generated noise signal, generated by compressed air, is used to determine the propagation time, which is measured at the transmitter and receiver to determine the propagation time between the transmitter and receiver by cross-correlation of these signals. Reliable calculation requires relatively long measurement cycles. Since the compressed air consumption of sound transmitters is very high, the method has never been used in the cement industry due to the high costs involved. Moreover, compressed air injected into large Petition 870220048584, dated 02 / 06 / 2022, pp. 104 / 145 3 / 26 quantities in the cement process disrupt the process as false air, whereas in power plants this accounts for a comparatively small proportion of the combustion air and is easy to tolerate. A sufficiently fast, accurate and reliable measurement of gas temperature in the cement sector is not available. Furthermore, there is no measuring system that can measure not only the temperature but also the enthalpy of the gas.

[004] It would therefore be desirable to have a robust and durable device available at least for temperature measurement, whereby a temperature measurement of up to 2,000°C can be carried out reliably, robustly, very quickly and largely independently of interfering influences, such as dust and dirt, in the production process in operation. SUMMARY

[005] It is an object of the invention to provide a robust and durable device at least for temperature measurement, whereby a temperature measurement of up to 2,000°C can be performed very quickly in the production process in operation in a reliable, robust and largely independent manner from interfering influences such as dust and dirt.

[006] The objective is solved by a device for at least one acoustic temperature measurement in a gaseous medium passing through a medium channel by means of time-operation measurement of an acoustic pulse flowing through the gaseous medium from at least one first transmitter arrangement to at least one first receiver arrangement, the first transmitter arrangement comprising a sound pulse generator to generate the acoustic pulse, which is connected by a first acoustic channel to a transmitter that transmits the acoustic pulse into the medium, the first acoustic channel being of acoustically dispersive design, and the first receiver arrangement comprising a receiver to receive the acoustic pulse after it has passed through the medium and to transmit it by means of a second acoustic channel to a first microphone, preferably a piezoelectric microphone, for detection of the acoustic pulse, the first acoustic channel being curved Petition 870220048584, dated 02 / 06 / 2022, pp. 105 / 145 4 / 26 in the direction of the sound pulse generator in such a way that the radiant heat of the medium in the sound pulse generator is at least greatly reduced, wherein at least the transmitter comprises, on its side facing the medium to be measured, an interference element that retroreflects a portion of the acoustic pulse to the first acoustic channel of the first transmitter arrangement, wherein a second microphone, preferably arranged on the side of the transmitter facing the sound pulse generator, is arranged for detecting the retroreflected portion of the acoustic pulse, the device further comprising a pulse discriminator designed to determine the arrival times of the recorded acoustic pulses in a suitable manner and to transmit them to an evaluation unit designed to determine the temperature of the medium from the time of operation of the acoustic pulse from the transmitter to the receiver,taking into account the arrival times determined by the pulse discriminator and the acoustic pulses detected by the first and second microphones.

[007] Gas temperature measurement is based on the fact that the speed of sound in gases over wide limits is only a function of temperature, but not of pressure. The temperature of a gas can therefore be determined by measuring the speed of sound. For a given gas composition, the specific gas constant and the isentropic exponent are fixed. The speed of sound, therefore, depends only on the temperature. Thus, by measuring the speed of sound in a gas, information about the gas temperature is obtained, according to which, the measurement is independent of the gas pressure and the gas density.

[008] Process gases in the cement industry are mainly air or combustion exhaust gases and have high temperatures but low heat capacity. In order to measure the temperature of a gas with a shielded thermocouple, it is necessary to wait until the sensor is in thermal equilibrium with the medium; this usually takes several reaction times. Since the air in the intended applications is additionally contaminated with abrasive dust, thermocouples in the cement industry are even more heavily shielded, which extends Petition 870220048584, dated 02 / 06 / 2022, pp. 106 / 145 5 / 26 Additionally, the reaction time. Experience has shown that temperature sensors in the cement industry have reaction times ranging from a few minutes to 15 minutes. Cement clinker dust is very abrasive, and consumers specify a service life of between two and eight weeks for steel-metallized thermocouples used in the heat exchanger tower and clinker cooler. Due to the acoustic measurement technology used, the device according to the present invention is located outside the zone of flowing gases and is therefore unaffected by the gas flow, enabling service life cycles of at least the inspection interval (approximately one year).

[009] Conversely, the device according to the invention will not extend beyond the refractory insulation material into the gas flow and will be additionally purged with air, so that the entire device is mechanically and thermally much less stressed. The measurement zone corresponds to the entire path traversed by the acoustic pulse. The average temperature value along the path length is obtained. For control systems that work with gas flow energies / enthalpies, a measurement like this is a much more reliable signal.

[010] The medium can be any gas with any composition. The medium channel denotes any channel, volume, or installation through which the medium passes. As an example, the medium channel can be a pipe, a preheating unit, a gas inlet, a furnace, a chimney, or anything else through which the gaseous medium can flow. An acoustic channel is a hollow connection between the sound pulse generator and the transmitter output, and between the receiver input and the microphone, through which acoustic waves pass. Acoustic channels can have any shape and cross-sectional geometry suitable for measurement.

[011] The first curved acoustic channel prevents heat radiation from the medium being measured from falling onto the sound pulse generator, thus protecting it from the high temperatures of the medium, for example, in cement kilns up to 2,000°C, since the acoustic connection through the transmitter represents an open channel for the Petition 870220048584, dated 02 / 06 / 2022, pp. 107 / 145 6 / 26 half.

[012] The temperature at the transmitter and receiver is unknown due to their direct contact with the hot medium to be measured, nor is the temperature distribution from the transmitter output to the medium along the acoustic channel in the direction of the sound pulse generator. This results in an unknown disturbance that can considerably distort the measurement result. This interference element makes it possible to measure the temperature at the transmitter section and correct the operating time signal in this way. Such an arrangement can also be made at the receiver side. For simplicity, however, it can also be assumed that the interference at the receiver is of the same magnitude and that the correction signal from the transmitter side can also be used at the receiver side during temperature calculation.

[013] Piezoelectric microphones are not very sensitive to temperature and are therefore suitable as primary and secondary microphones. They are therefore more robust and economical. Possible deficits in the sensitivity and speed of these microphones can be compensated for with appropriately designed input amplifiers.

[014] Therefore, the device according to the present invention is a robust and durable device that enables temperature measurements up to 2,000°C, which can be performed very quickly in the production process in operation in a reliable, robust and largely independent manner from interfering influences such as dust and dirt. For example, in gases at 1,450°C, a measurement accuracy as low as 1K can be achieved corresponding to an operating time measurement accuracy of less than 2 ps. The distance between the transmitter and receiver can be 1 to 10 meters.

[015] In one embodiment, at least the first acoustic channel, preferably also the second acoustic channel, is cooled from the outside by means of a cooling device. This prevents the gas in the supply line from heating up, which reduces the operating time of the acoustic pulse in the medium to be Petition 870220048584, dated 02 / 06 / 2022, pages 108 / 145 7 / 26 measured. This also protects the sound generator from heat radiation and damage. The same applies to the components on the receiver side, especially the first microphone.

[016] In another embodiment, the transmitter and receiver are designed as funnels that open linearly, exponentially, or by any appropriate function in the direction of the medium. This ensures good coupling of the sound pulse generator in the measurement section between the transmitter and the receiver.

[017] In another embodiment, the sound pulse generator comprises a correspondingly controlled conductor and elastic metal diaphragm for generating the acoustic pulse or is designed as a pressure chamber loudspeaker or other device for producing short, high-pressure pulses. A metal diaphragm is particularly robust against high temperatures, which do not have the measuring temperature in the medium at the diaphragm location, but are nevertheless considerable. To generate a strong acoustic pulse, a conductive elastic membrane such as the metal diaphragm is stretched in front of a low-impedance coil. If a short current pulse is sent through the coil, eddy currents are induced in the membrane by induction, leading to a pulse-type repulsion of the membrane. If the membrane is allowed to work in a pressure chamber, a strong, precisely defined acoustic pulse results.In order to achieve the best possible acoustic coupling of the sound pulse generator in the measurement section, a funnel with a linear, exponential, or any other appropriate opening function is usually used.

[018] In another embodiment, the first microphone comprises a microphone amplifier and a pulse discriminator. This allows the arrival time of the acoustic pulse to be measured with high precision. A fast microcontroller (ARM) can be used as a pulse discriminator. This makes it possible to adapt the response threshold to the pulse shape and achieve high time resolution in the submillisecond range.

[019] In another embodiment, in the second acoustic channel, a temperature protection diaphragm is arranged in front of the first microphone in the direction of Petition 870220048584, dated 02 / 06 / 2022, pp. 109 / 145 8 / 26 a direction of the acoustic pulse current. This allows temperature-sensitive microphones to be shielded from the hot medium, which is what makes the use of particularly temperature-sensitive microphones possible in the first place.

[020] In another embodiment, the second microphone is arranged outside the transmitter and is connected to a wall of the transmitter by means of an acoustic supply line for detection of the retroreflected part of the acoustic pulse. Due to the arrangement of the second microphone outside the transmitter, the transmitter does not disturb the transmission of the acoustic pulse by shadowing effects and is, moreover, protected by the narrow supply line from an excessively high temperature effect of the medium in the transmitter.

[021] In another embodiment, the pulse discriminator is adapted to use a zero crossing of the acoustic pulse as a trigger time for the arrival time of the acoustic pulse. The acoustic pulse has a waveform in which the signal initially lies below an average amplitude, then rises sharply and falls below the average amplitude again at the falling edge of the pulse. If the average amplitude is set as the zero line, the waveform of the acoustic pulse has two zero crossings, before and after the maximum of the acoustic pulse. These zero crossings can also be used as a trigger.

[022] In another embodiment, the interference element is configured as a ring or a suitable shape around the transmitter output. In this way, the backreflected signal becomes stronger than in the case of a single interference element that is only locally present. Furthermore, the influence of the interference ring on the acoustic pulse is symmetrical.

[023] In another embodiment, the first transmitter array and the first receiver array are arranged on opposite sides of a path of interest through the medium channel or the medium channel. This provides the shortest distance which provides the shortest possible operating time between the transmitter and the receiver, increasing the measurement accuracy for the determined temperature.

[024] In another embodiment, the device comprises at least one Petition 870220048584, dated 02 / 06 / 2022, pp. 110 / 145 9 / 26 second transmitter arrangement comprising the same components as the first transmitter arrangement, wherein the first and second transmitter arrangements are arranged on the same side of the medium channel at different heights relative to a flow direction of the gaseous medium, wherein one of the first and second transmitter arrangements is arranged above the first receiver arrangement and the other is arranged below the first receiver arrangement relative to the flow direction of the gaseous medium, wherein both transmitter arrangements are adapted to transmit their acoustic pulses in the direction of the receiver at different times in order to provide acoustic pulses with operating times in one direction partially against and in the other direction partially along the flow direction of the gaseous medium.Since the transmitter arrays are arranged at different heights relative to the receiver array, for one of the transmitter arrays, the measured operating time of the acoustic pulse includes a deceleration contribution, as the pulse runs partially against the flow of the gas medium, while for the other transmitter array, the operating time of the acoustic pulse includes an acceleration contribution, as the pulse runs partially with the flow of the gas medium. From the difference between the two detected operating times, the average flow velocity of the gas medium through the channel can be calculated. Using the known cross-sectional area of ​​the channel, the volume flow rate can be calculated.

[025] In another embodiment, the device comprises at least one second receiver arrangement comprising the same components as the first receiver arrangement, wherein the first and second receiver arrangements are arranged on the same side of the medium channel at different heights relative to the flow direction of the gaseous medium, wherein one of the first and second receiver arrangements is arranged above the first transmitter arrangement and the other is arranged below the first receiver arrangement relative to the flow direction of the gaseous medium, wherein both receiver arrangements are adapted to receive the acoustic pulse from the transmitter at different times, wherein the transmitter is adapted to transmit the acoustic pulses to the first and / or second receiver arrangements in order to provide pulses Petition 870220048584, dated 02 / 06 / 2022, pp. 111 / 145 10 / 26 acoustics with operating times in one direction partially against and in the other direction partially along the flow direction of the gaseous medium, where the transmitter is adapted to transmit the acoustic pulses either to the first or to the second receiver arrangement.

[026] In another alternative embodiment, the first transmitter arrangement is adapted to be operated on demand as a second receiver arrangement comprising the same components as the first receiver arrangement required to also receive the acoustic pulse and wherein the first receiver arrangement is adapted to be operated on demand as a second transmitter arrangement comprising the same components as the first transmitter arrangement required to also transmit the acoustic pulse, wherein the first transmitter and receiver arrangements are arranged at different heights relative to the flow direction of the gas medium, wherein the first transmitter arrangement is adapted to transmit acoustic pulses at different times from the second transmitter arrangements in order to provide acoustic pulses with operating times in one direction partially against and in the other direction partially along the flow direction of the gas medium.Here, a part of the components on the transmitter side can also be used to receive acoustic pulses from the receiver side, also acting as a transmitter side that enables providing a device that enables the determination of gas volume flow with less effort and components, as in the modalities described previously.

[027] The modalities, in which the transmitter and receiver are arranged at different heights ((a) two transmitters and one receiver, (b) one transmitter and two receivers, or (c) two transmitter / receiver arrangements, all installed at different heights relative to each other and in the direction of gas flow), enable the measurement of gas volume flow and enthalpy of the medium. From the precise measurement of temperature and flow velocity simultaneously measured, the volume flow per unit time in the measuring section is determined for a known cross-section of the measuring section and, finally, the enthalpy of the gas. Petition 870220048584, dated 02 / 06 / 2022, pp. 112 / 145 The 11 / 26 flow rate is calculated by the device according to the present invention.

[028] The invention further relates to a cement production plant comprising at least one device according to the present invention. Due to their size, cement kilns in cement production plants need to operate 24 hours a day. They are usually only deactivated for annual inspections or in the event of serious malfunctions. The start-up and deactivation procedures usually take several days and are therefore avoided as much as possible.

[029] The temperature and enthalpy measuring device according to the present invention should be used as a reference variable. It should therefore achieve at least the same service life as the furnace, which is satisfied by the device according to the present invention.

[030] The invention further relates to a method for operating a device according to the present invention at least for an acoustic temperature measurement in a gaseous medium passing through a medium channel by means of time-operation measurement of an acoustic pulse flowing through the gaseous medium from at least one first transmitter arrangement arranged on one side of a medium channel to at least one first receiver arrangement arranged on the other side of the medium channel, comprising steps of: - Generate the acoustic pulse using a sound pulse generator; - transmitting the acoustic pulse by means of a first acoustic channel connected to a transmitter, which transmits the acoustic pulse into the interior of the medium, wherein the first acoustic channel is of acoustically dispersive design and is curved in the direction of the sound pulse generator in such a way that the radiant heat of the medium in the sound pulse generator is at least enormously reduced; - detecting a retroreflected portion of the acoustic pulse by a second microphone arranged in the first transmitter array, preferably arranged on the side of the transmitter facing the sound pulse generator, wherein at least the transmitter comprises, on its side facing the medium to be measured, an element Petition 870220048584, dated 02 / 06 / 2022, pages 113 / 145 12 / 26 interference to retroreflect part of the acoustic pulse to the first acoustic channel; - to receive the acoustic pulse after it has passed through the medium via a receiver; - transmit the acoustic pulse through a second acoustic channel to a first microphone, preferably a piezoelectric microphone, to detect the acoustic pulse; - To determine an appropriate arrival time for acoustic pulses recorded by a pulse discriminator and transmit them to an evaluation unit; - Determine the temperature of the medium based on the operating time of the acoustic pulse from the transmitter to the receiver by the evaluation unit, taking into account the arrival times determined by the pulse discriminator and the acoustic pulses detected by the first and second microphones; - Determine the operating time inside the transmitter and receiver by measuring the operating time of the retroreflected portion of the pulse by the interference elements at the transmitter output.

[031] In one embodiment of the method, the device comprises - at least one second transmitter arrangement comprising the same components as the first transmitter arrangement, wherein the first and second transmitter arrangements are arranged on the same side of the medium channel at different heights relative to a flow direction of the gaseous medium, wherein one of the first and second transmitter arrangements is arranged above the first receiver arrangement and the other is arranged below the first receiver arrangement relative to the flow direction of the gaseous medium, comprising the step of generating and transmitting acoustic pulses in the direction of the receiver at different times by both transmitter arrangements; and / or - at least one second receiver array comprising the same components as the first receiver array, wherein the first and second receiver arrays are arranged on the same side of the medium channel at different heights in Petition 870220048584, dated 02 / 06 / 2022, pages 114 / 145 13 / 26 with respect to the flow direction of the gaseous medium, wherein one of the first and second receiver arrangements is arranged above the first transmitter arrangement and the other is arranged below the first receiver arrangement with respect to the flow direction of the gaseous medium comprising the steps of generating and transmitting the acoustic pulses by the transmitter either to the first or to the second receiver arrangement and receiving the acoustic pulse from the transmitter at different times by both receiver arrangements; and / or - the first transmitter arrangement is adapted to be operated on demand as a second receiver arrangement comprising the same components as the first receiver arrangement required to also receive the acoustic pulse, and wherein the first receiver arrangement is adapted to be operated on demand as a second transmitter arrangement comprising the same components as the first transmitter arrangement required to also transmit the acoustic pulse, wherein the first transmitter and receiver arrangements are arranged at different heights relative to the flow direction of the gaseous medium, comprising the step of generating and transmitting acoustic pulses from both transmitters to both receivers at different times; and - Calculate the volume flow rate of the gaseous medium through the medium channel from the difference between the two detected operating times, one partially against and one partially along the flow direction of the gaseous medium by the evaluation unit; - preferably followed by the calculation of the gas enthalpy from the temperature and volume flow rate through the evaluation unit.

[032] The above-described embodiments may be used individually or in any combination with each other, even in deviation from the preceding references of the dependent claims in relation to each other stated in the claims. Petition 870220048584, dated 02 / 06 / 2022, pp. 115 / 145 14 / 26 BRIEF DESCRIPTION OF THE DRAWINGS

[033] These and other aspects of the invention are illustrated in detail in the following drawings.

[034] Figure 1 is a schematic side view of an embodiment of an acoustic temperature measuring device according to the present invention installed in a cement production facility; Figure 2 is a schematic side view of another embodiment of an acoustic temperature measuring device according to the present invention installed in a cement production facility; Figure 3 is a schematic side view of another embodiment of a device for measuring acoustic temperature and gas flow according to the present invention installed in a cement production plant using two transmitter arrays and one receiver array; Figure 4 is a schematic side view of another embodiment of a device for measuring acoustic temperature and gas flow according to the present invention installed in a cement production plant using a transmitter arrangement and two receiver arrangements; Figure 5 is a schematic side view of another embodiment of a device for measuring acoustic temperature and gas flow according to the present invention installed in a cement production plant using an integrated transmitter and receiver arrangement on both sides of the medium channel; Figure 6 is a schematic view of a cement production plant according to the present invention comprising a device for measuring acoustic temperature and / or gas flow according to the present invention; Figure 7 is a diagram of an acoustic pulse as a function of operating time for three different acoustic pulses; Figure 8 is an embodiment of a method for measuring acoustic temperature and gas flow according to the present invention. Petition 870220048584, dated 02 / 06 / 2022, pages 116 / 145 15 / 26 DETAILED DESCRIPTION OF THE INVENTION

[035] Figure a shows a schematic side view of an embodiment of a device 1 for acoustic temperature measurement according to the present invention in a gaseous medium M passing through a medium channel 110 of an installation 100 (see Figure 6) for cement production by means of time-operation measurement of an acoustic pulse AP current through the gaseous medium M from a first transmitter arrangement TA1 to a first receiver arrangement RA1, wherein the time-operation is an average value over the distance between the first transmitter arrangement TA1 and the first receiver arrangement RA1 of, for example, one or more meters. The response time is below 1 second, the measurement accuracy about 1% or less of the total time-operation.The first transmitter arrangement TA1 of device 1 comprises a sound pulse generator 2 for generating the acoustic pulse AP, which is connected by a first acoustic channel 3 to a transmitter 4 that transmits the acoustic pulse AP into the interior of medium M, the first acoustic channel 3 being of acoustically dispersive design. The sound pulse generator 2 comprises a correspondingly controlled conductor and elastic metal diaphragm 21 for generating the acoustic pulse AP or is designed as a pressure chamber loudspeaker or other device capable of producing short, high-pressure pulses. The first receiver arrangement RA1 of device 1 comprises a receiver 5 for receiving the acoustic pulse AP after it has passed through medium M and for transmitting it via a second acoustic channel 6 to a first microphone 7, preferably a piezoelectric microphone 7, for detecting the acoustic pulse AP.The first transmitter array TA1 and the first receiver array RA1 are arranged on opposite sides of the medium channel 110, achieving a minimum distance between both components in order to decrease the operating time, resulting in better relative measurement accuracy for the operating time. Here, the transmitter 4 and the receiver 5 are designed as funnels that open linearly, exponentially, or according to any appropriate function in the direction of the medium M. The first acoustic channel 3 is curved in the direction of the sound pulse generator 2. Petition 870220048584, dated 02 / 06 / 2022, pp. 117 / 145 16 / 26 in such a way that the radiant heat of the medium M in the sound pulse generator 2 is at least enormously reduced. In order to further reduce thermal effects, the first acoustic channel 3 and also the second acoustic channel 6 are cooled from the outside by means of a cooling device 11. The cooling device may be a fan providing cooled air or it may be a cooling reservoir arranged around the acoustic channels 3, 6 comprising a cooling fluid. The second acoustic channel 6 further comprises a temperature protection diaphragm 61 arranged in front of the first microphone 7 in the direction of the current LR of the acoustic pulse AP. The temperature protection diaphragm 61 is adapted to transmit the acoustic pulse AP but to make it difficult for heat radiation to penetrate the diaphragm 61.Transmitter 4 comprises, on its side 41 facing the medium M to be measured, an interference element 42 (see figure 2) that retroreflects a portion RI of the acoustic pulse AP to the first acoustic channel 3 of the first transmitter array TA1, wherein a second microphone 8, preferably arranged on the side 43 of transmitter 4 facing the sound pulse generator 2, is arranged for detection of the retroreflected portion RI of the acoustic pulse AP (not shown in figure 1, for details see figure 2).Device 1 further comprises a pulse discriminator 9 designed to determine the arrival times AT of the recorded acoustic pulses AP in a suitable manner and to transmit them to an evaluation unit 10 designed to determine the temperature of the medium M from the operating time of the acoustic pulse AP from the transmitter 4 to the receiver 5, taking into account the arrival times AT determined by the pulse discriminator and the acoustic pulses RI, AI detected by the first and second microphones 7, 8.

[036] Figure 2 shows a schematic side view of the acoustic temperature measuring device according to the present invention installed in a cement production plant 100, as shown in Figure 1, with the interference element 42 in more detail. The transmitter 4 comprises, on its side 41 facing the medium M to be measured, an interference element 42 which Petition 870220048584, dated 02 / 06 / 2022, pages 118 / 145 17 / 26 retroreflects a portion RI of the acoustic pulse AP to the first acoustic channel 3 of the first transmitter array TA1, wherein a second microphone 8 is arranged on the side 43 of the transmitter 4 facing the sound pulse generator 2 for detection of the retroreflected portion RI of the acoustic pulse AP. The second microphone 8 is arranged on the exterior of the transmitter 4 and is connected to a wall 44 of the transmitter 4 via an acoustic supply line 81 for detection of the retroreflected portion RI of the acoustic pulse AP. The acoustic supply line serves as temperature protection for the second microphone 8. Here, the interference element 42 is configured as a ring around the output 41 of the transmitter 4.

[037] Figure 3 shows a schematic side view of another embodiment of a device 1 for acoustic temperature and gas flow measurements according to the present invention installed in a cement production plant 100 using two transmitter arrays and one receiver array.Device 1 comprises, in addition to the first transmitter arrangement TA1, a second transmitter arrangement TA2 comprising the same components as the first transmitter arrangement TA1, wherein the first and second transmitter arrangements TA1, TA2 are arranged on the same side of the medium channel 110 at different heights H1, H2 relative to a flow direction DF of the gaseous medium M, wherein one of the first and second transmitter arrangements TA1, TA2 is arranged above the first receiver arrangement RA1 and the other is arranged below the first receiver arrangement RA1 relative to the flow direction DF of the gaseous medium M, wherein both transmitter arrangements TA1, TA2 are adapted to transmit their acoustic pulses AP in the direction of the receiver 5 at different times in order to provide acoustic pulses AP with operating times in one direction partially against and in the other direction partially along the flow direction DF of the gaseous medium M.Again, the first and second transmitter arrays TA1, TA2 and the first receiver array RA1 are arranged on opposite sides of the middle channel 110. The transmitter arrays TA1, TA2 can be adjusted to emit the acoustic pulse AP directly in the direction of the receiver array RA1 by slightly tilting the transmitter arrays TA1, TA2 by a certain amount. Petition 870220048584, dated 02 / 06 / 2022, pp. 119 / 145 18 / 26 angle adapted to the difference between the first and second heights H1, H2.

[038] Figure 4 shows a schematic side view of another embodiment of a device for measuring acoustic temperature and gas flow according to the present invention installed in a cement production plant using a transmitter arrangement and two receiver arrangements. Device 1 comprises at least one second receiver arrangement RA2 comprising the same components as the first receiver arrangement RA1, wherein the first and second receiver arrangements RA1, RA2 are arranged on the same side of the medium channel 110 at different heights H1, H2 relative to the flow direction DF of the gaseous medium M, wherein one of the first and second receiver arrangements RA1, RA2 is arranged above the first transmitter arrangement TA1 and the other is arranged below the first receiver arrangement RA1 relative to the flow direction DF of the gaseous medium M, in which both receiver arrangements RA1, RA2 are adapted to receive acoustic pulse AP from transmitter 4 at different times,wherein transmitter 4 is adapted to transmit AP acoustic pulses to the first and / or second receiver arrays RA1, RA2 in order to provide AP acoustic pulses with operating times in one direction partially against and in the other direction partially along the flow direction DF of the gaseous medium M. Again, the first transmitter array TA1 and the first and second receiver arrays RA1, RA2 are arranged on opposite sides of the medium channel 110. The receiver arrays RA1, RA2 can be adjusted to receive the AP acoustic pulse directly from the transmitter array TA1 by slightly tilting the receiver arrays RA1, RA2 at a certain angle adapted to the difference between the first and second heights H1, H2.

[039] Figure 5 shows a schematic side view of another embodiment of a device for measuring acoustic temperature and gas flow according to the present invention installed in a cement production plant using an integrated transmitter and receiver arrangement on both sides of the medium channel. The first transmitter arrangement TA1 is adapted to be operated on demand as a second receiver arrangement RA2 comprising the same components as Petition 870220048584, dated 02 / 06 / 2022, pages 120 / 145 19 / 26 first receiver arrangement RA1 required to also receive the acoustic pulse AP and wherein the first receiver arrangement RA1 is adapted to be operated on demand as a second transmitter arrangement TA2 comprising the same components as the first transmitter arrangement TA1 required to also transmit the acoustic pulse AP, wherein the first transmitter and receiver arrangement is arranged at different heights relative to the flow direction DF of the gaseous medium M, wherein the first transmitter arrangement TA1 is adapted to transmit acoustic pulses AP at different times from the second transmitter arrangements TA2 in order to provide acoustic pulses AP with operating times in one direction partially against and in the other direction partially along the flow direction DF of the gaseous medium M.Again, the first transmitter array TA1 and the first receiver array RA1, as well as the second transmitter array TA2 and the second receiver array RA2, are arranged on opposite sides of the middle channel 110. The transmitter-receiver array TA1, RA2 can be adjusted to emit or receive the acoustic pulse AP directly towards or from the transmitter-receiver array RA1, TA2 by slightly tilting the transmitter-receiver arrays TA1, RA2 and RA1, TA2 at a certain angle adapted to the difference between the first and second heights H1, H2.

[040] Figure 6 shows a schematic view of a cement production plant 100 according to the present invention comprising a device 1 for acoustic temperature and / or gas flow measurements according to the present invention. During cement production, the use of continuous measurement by measuring and analysis equipment, such as device 1 according to the present invention, is necessary at many points. With the help of measurements, the function and efficiency of the plant operation must be ensured with the aim of saving energy and monitoring quality. An additional aspect is the safety of people and plants by monitoring for explosion or fire hazards, for example, in the electrostatic precipitator and coal silo. In order to meet legal requirements regarding environmental protection and compliance with permissible limit values, plants used for gas cleaning Petition 870220048584, dated 02 / 06 / 2022, pp. 121 / 145 20 / 26 residual levels are checked and residual pollutant concentrations in the waste gas are monitored. The extremely harsh environmental conditions in the rotary kiln place the highest demands on extraction techniques today. Gas temperatures up to 1,500°C, dust concentrations up to 2,000 g / m3, and high alkaline, sulfate, and chloride contents are typical for the rotary kiln environment. Inside the rotary kiln, it is very difficult to measure the gas temperature using state-of-the-art industrial standard methods. If the secondary and primary air temperatures are known very imprecisely, the combustion capacity of the two burners tends to be set too high to achieve the required process temperatures. In Germany and Europe, the typical production capacity of rotary cement kilns is approximately 3,000 tons per day. The thermal energy requirement is given as approximately 3.200 kJ / kg of clinker, corresponding to a net thermal output of 111 MW, which must be applied through the primary burner and calciner. Due to losses, fluctuations in raw material quality and moisture, and the fact that the temperatures of the gas streams involved are not exactly known, the thermal output of the primary burner and calciner needs to be 111 MW; the actual combustion capacity is up to 150 MW. With the device for measuring temperature and enthalpy according to the present invention, it is possible to reduce the specific energy requirement in clinker production and achieve this by specifically adjusting the gas temperatures. At air temperatures of about 1,000°C, for example, an energy change of 100 kJ per m3 corresponds to a temperature change of approximately 80 K. In order to be able to regulate the temperature precisely, the device for temperature measurement according to the invention is therefore required.This precise temperature measurement can also be used, without limitation, in the clinker cooler inlet area, in the tertiary air duct, possibly also in the exhaust air duct, in the downpipes and in the calciner. Due to the low thermal capacity of the gases and the high flow rates, reaction times in the range of minutes or less, this is only possible by the present method. Petition 870220048584, dated 02 / 06 / 2022, pages 122 / 145 21 / 26 invention. In addition to improving energy efficiency, rapid and accurate temperature measurement plays a key role in reducing nitrogen oxides in the heat exchanger tower. The SNCR (selective non-catalytic reduction) process, which is widely used, requires a temperature window of 850 to 900°C to optimize the process during the injection of the reducing agent.

[041] Figure 7 shows an intensity diagram I of an acoustic pulse AP as a function of operating time t for three different acoustic pulses AP after analysis by pulse discriminator 9 with a sampling rate of 200 kHz corresponding to 5 ps between two neighboring sample points. Pulse discriminator 9 (see Figures 1, 3, -5) is adapted to use a zero crossing of the acoustic pulse AP as a trigger time TP for the arrival time AT of the acoustic pulse AP. The trigger time TR (trigger point) can be obtained by interpolation between sample points around the trigger time TR. As the acoustic pulse AP traverses the measurement distance, it is attenuated in an unpredictable manner when dust load fluctuates and when gas seeps occur. The arrival AT of a pulse is determined at the moment when it exceeds a specified limit.If the AP pulse has not been normalized, an unattenuated AP pulse will exceed the measurement limit by an earlier arrival time AT than an attenuated pulse, thus falsifying the arrival time AT. By detecting the trigger time TR instead of evaluating a measurement limit, the derived arrival time AT becomes independent of the intensity I of the AP acoustic pulse and therefore independent of the dust load of the medium, which greatly increases the measurement accuracy. For example, in gases at 1450°C, a measurement accuracy of 1K is achieved corresponding to an operating time measurement accuracy of less than 2 ps.

[042] Figure 8 shows an embodiment of a method 100 for acoustic temperature and gas flow measurements according to the present invention for operating a device 1 according to the present invention at least for an acoustic temperature measurement in a gaseous medium passing through a channel of Petition 870220048584, dated 02 / 06 / 2022, pp. 123 / 145 22 / 26 medium 110 by means of the time-operation measurement of an acoustic pulse AP current through the gaseous medium M from at least one first transmitter arrangement TA1 arranged on one side of a medium channel 110 to at least one first receiver arrangement RA1 arranged on the other side of the medium channel 110, comprising the steps of generating 210 the acoustic pulse AP by a sound pulse generator 2; transmitting 220 the acoustic pulse AP by means of a first acoustic channel connected 3 to a transmitter 4, which transmits the acoustic pulse AP into the interior of the medium M, wherein the first acoustic channel 3 is of acoustically dispersive design and is curved in the direction of the sound pulse generator 2 in such a way that the radiant heat of the medium M on the sound pulse generator 2 is at least greatly reduced;detect 230 a retroreflected portion RI of the acoustic pulse AP by a second microphone arranged in the first transmitter arrangement TA1, preferably arranged on the side 43 of the transmitter 4 facing the sound pulse generator 2, in parallel to the acoustic pulse AP transmitted to the receiver 5, wherein at least the transmitter 4 comprises, on its side 41 facing the medium M to be measured, an interference element 42 to retroreflect the portion RI of the acoustic pulse AP to the first acoustic channel 3; receive 240 the acoustic pulse AP after it has passed through the medium M via a receiver 5; transmit 250 the acoustic pulse AP via a second acoustic channel 6 to a first microphone 7, preferably a piezoelectric microphone 7, to detect the acoustic pulse AP; determine 260 an arrival time AT of the recorded acoustic pulses AP by a pulse discriminator 9 in a suitable manner and transmit the same to an evaluation unit 10;and determine 270 the temperature of medium M from the operating time of the acoustic pulse AP from transmitter 4 to receiver 5 by evaluation unit 10 taking into account the arrival times AT determined by pulse discriminator 9 and the acoustic pulses RI, AI detected by the first and second microphones 7, 8.;

[043] In the case where device 1 comprises at least one second transmitter arrangement TA2 comprising the same components as the first transmitter arrangement TA1, wherein the first and second transmitter arrangements TA1, TA2 are Petition 870220048584, dated 02 / 06 / 2022, pages 124 / 145 23 / 26 arranged on the same side of the medium channel 110 at different heights H1, H2 relative to a flow direction DF of the gaseous medium M, wherein one of the first and second transmitter arrays TA1, TA2 is arranged above the first receiver array RA1 and the other is arranged below the first receiver array RA1 relative to the flow direction DF of the gaseous medium M, the method 100 comprising the step of generating and transmitting 280 acoustic pulses AP in the direction of the receiver 5 at different times by both transmitter arrays TA1, TA2.

[044] In the case of device 1 comprising at least one second receiver arrangement RA2 comprising the same components as the first receiver arrangement RA1, wherein the first and second receiver arrangements RA1, RA2 are arranged on the same side of the medium channel 110 at different heights H1, H2 relative to the flow direction DF of the gaseous medium M, wherein one of the first and second receiver arrangements RA1, RA2 is arranged above the first transmitter arrangement TA1 and the other is arranged below the first receiver arrangement RA1 relative to the flow direction DF of the gaseous medium M, the method 100 comprises the steps of generating and transmitting the acoustic pulses AP by transmitter 4 to either the first or second receiver arrangement RA1, RA2 and receiving the acoustic pulse AP from transmitter 4 at different times by both receiver arrangements RA1, RA2.

[045] In the case where the first transmitter arrangement TA1 is adapted to be operated on demand as a second receiver arrangement RA2 comprising the same components as the first receiver arrangement RA1 required to also receive the acoustic pulse AP and wherein the first receiver arrangement RA1 is adapted to be operated on demand as a second transmitter arrangement TA2 comprising the same components as the first transmitter arrangement TA1 required to also transmit the acoustic pulse AP, wherein the first transmitter and receiver arrangement is arranged at different heights relative to the flow direction DF of the gaseous medium M, method 100 comprises step 300 of generating and transmitting acoustic pulses from both transmitters TA1, TA2 to both receivers RA1, RA2 at different times. Petition 870220048584, dated 02 / 06 / 2022, pages 125 / 145 24 / 26

[046] In all three previous cases, method 100 comprises the additional steps of calculating 310 a volume flow of the gaseous medium M through the medium channel 110 from a difference of both detected operating times, one partially against and one partially along the flow direction DF of the gaseous medium M, by the evaluation unit 10, followed by calculating 320 an enthalpy of the gas from the temperature and volume flow by the evaluation unit 10.

[047] The embodiments shown here are merely examples of the present invention and should not, therefore, be understood as restrictive. Alternative embodiments considered by those skilled in the art are equally covered by the scope of protection of the present invention. LIST OF REFERENCE NUMBERS device invented for acoustic temperature measurement sound pulse generator metal diaphragm first acoustic channel which is acoustically dispersive transmitter transmitter side facing the medium interference element in the transmitter transmitter side facing the sound pulse generator transmitter wall receiver second acoustic channel temperature protection diaphragm first microphone microphone amplifier second microphone acoustic supply line to second microphone pulse discriminator evaluation unit Petition 870220048584, dated 02 / 06 / 2022, pages 126 / 145 25 / 26 cooling device at least for the first acoustic channel 100 installation for cement production 110 middle channel 200 A method for operating a device according to the present invention 210 Acoustic pulse generation by a sound pulse generator 220 transmission of the acoustic pulse through a first acoustic channel connected to a transmitter 230 detection of a retroreflected portion of the acoustic pulse by a second microphone 240 reception of the acoustic pulse after passing through the medium via a receiver 250 transmission of the acoustic pulse through a second acoustic channel to a first microphone 260 Determining the arrival time of acoustic pulses recorded by a pulse discriminator 270 Determination of the temperature of the medium 280 transmission of acoustic pulses towards the receiver at different times by both transmitter arrays (first and second) 290 transmission of acoustic pulses by the transmitter to either the first or second receiver arrangement and reception of the acoustic pulse from the transmitter at different times by both receiver arrangements 300 transmission of acoustic pulses from both transmitters to both receivers at different times. 310 Calculation of a volume flow rate of the gaseous medium through the medium channel from a difference between the two detected operating times. 320 Calculation of gas enthalpy from temperature and volume flow through the evaluation unit. AP acoustic pulse Petition 870220048584, dated 02 / 06 / 2022, pages 127 / 145 26 / 26 DF direction of gas flow H1 height of the installation of the first transmitter or receiver array in the middle channel. H2 height of the second transmitter or receiver array installation in the medium channel. LR direction of displacement of the acoustic pulse M is a gaseous medium, whose temperature must be determined. RA1 first receiver array RA2 second receiver arrangement RI is the portion of the acoustic pulse that is backreflected by the interference element. RT is the arrival time of the acoustic pulse. TA1 first transmitter arrangement TA2 first transmitter arrangement TR trigger time Petition 870220048584, dated 02 / 06 / 2022, pages 128 / 145

Claims

1 / 7 CLAIMS 1. Device (1) at least for an acoustic temperature measurement in a gaseous medium (M) passing through a medium channel (110) by means of time-operation measurement of an acoustic pulse (AP) flowing through the gaseous medium (M) from at least one first transmitter arrangement (TA1) to at least one first receiver arrangement (RA1), characterized in that the first transmitter arrangement (TA1) comprises a sound pulse generator (2) for generating the acoustic pulse (AP), which is connected by a first acoustic channel (3) to a transmitter (4) that transmits the acoustic pulse (AP) into the medium (M), the first acoustic channel (3) being of acoustically dispersive design, and the first receiver arrangement (RA1) comprises a receiver (5) for receiving the acoustic pulse (AP) after it has passed through the medium (M) and for transmitting it by means of a second acoustic channel (6) to a first microphone (7) for detection of the acoustic pulse (AP),the first acoustic channel (3) being curved towards the sound pulse generator (2) in such a way that the radiant heat of the medium (M) on the sound pulse generator (2) is at least greatly reduced, wherein at least the transmitter (4) comprises, on its side (41) facing the medium (M) to be measured, an interference element (42) which is configured as a ring or a suitable shape around the output of the transmitter (4) and retroreflects a portion (RI) of the acoustic pulse (AP) to the first acoustic channel (3) of the first transmitter arrangement (TA1), wherein a second microphone (8) is arranged for detection of the retroreflected portion (RI) of the acoustic pulse (AP),the device (1) further comprising a pulse discriminator (9) designed to determine the arrival times (AT) of the recorded acoustic pulses (AP) in a suitable manner and to transmit them to an evaluation unit (10) designed to determine the temperature of the medium (M) from the operating time of the acoustic pulse (AP) from the transmitter (4) to the receiver (5), taking into account the arrival times (AT) determined by the pulse discriminator and the acoustic pulses (RI, AI) detected by the first and second microphones (7, 8). Petition 870260036120, dated 17 / 04 / 2026, page 27 / 33 2 / 7, 2. Device (1) according to claim 1, characterized in that at least the first acoustic channel (3) and also the second acoustic channel (6) are cooled from the outside by means of a cooling device (11).

3. Device (1) according to claim 1 or 2, characterized in that the transmitters (4) and receivers (5) are designed as funnels that open linearly, exponentially or according to any appropriate function in the direction of the medium (M).

4. Device (1) according to any of the preceding claims, characterized in that the sound pulse generator (2) comprises a correspondingly controlled conductor and elastic metal diaphragm (21) for generating the acoustic pulse (AP) or being designed as a pressure chamber loudspeaker or other device for producing short high-pressure pulses.

5. Device (1) according to any of the preceding claims, characterized in that in the second acoustic channel (6), a temperature protection diaphragm (61) is arranged in front of the first microphone (7) in the direction of the current (LR) of the acoustic pulse (AP).

6. Device (1) according to any of the preceding claims, characterized in that the second microphone (8) is arranged outside the transmitter (4) and is connected to a wall (44) of the transmitter (4) by means of an acoustic supply line (81) for detection of the retroreflected (RI) part of the acoustic pulse. Petition 870260036120, 17 / 04 / 2026, p. 28 / 33 3 / 7 (AP).

7. Device (1) according to any of the preceding claims, characterized in that the pulse discriminator (9) is adapted to use a zero crossing of the acoustic pulse (AP) as a trigger time (TP) for the arrival time (AT) of the acoustic pulse (AP).

8. Device (1) according to any of the preceding claims, characterized in that the first transmitter arrangement (TA1) and the first receiver arrangement (RA1) are arranged on opposite sides of a path of interest through the medium channel or the medium channel (110).

9. Device (1) according to any of the preceding claims, characterized in that the device (1) comprises at least one second transmitter arrangement (TA2) comprising the same components as the first transmitter arrangement (TA1), wherein the first and second transmitter arrangements (TA1, TA2) are arranged on the same side of the medium channel (110) at different heights (H1, H2) relative to a flow direction (DF) of the gaseous medium (M), wherein one of the first and second transmitter arrangements (TA1, TA2) is arranged above the first receiver arrangement (RA1) and the other is arranged below the first receiver arrangement (RA1) relative to the flow direction (DF) of the gaseous medium (M), wherein both transmitter arrangements (TA1,TA2) are adapted to transmit their acoustic pulses (AP) towards the receiver (5) at different times in order to provide acoustic pulses (AP) with operating times in one direction partially against and in the other direction partially along the flow direction (DF) of the gaseous medium (M).

10. Device (1) according to any of the preceding claims Petition 870260036120, dated 04 / 17 / 2026, p. 29 / 33 4 / 7, characterized in that the device (1) comprises at least one second receiver arrangement (RA2) comprising the same components as the first receiver arrangement (RA1), wherein the first and second receiver arrangements (RA1, RA2) are arranged on the same side of the medium channel (110) at different heights (H1, H2) relative to the flow direction (DF) of the gaseous medium (M), wherein one of the first and second receiver arrangements (RA1, RA2) is arranged above the first transmitter arrangement (TA1) and the other is arranged below the first receiver arrangement (RA1) relative to the flow direction (DF) of the gaseous medium (M), wherein both receiver arrangements (RA1, RA2) are adapted to receive acoustic pulse (AP) from the transmitter (4) at different times,wherein the transmitter (4) is adapted to transmit acoustic pulses (AP) to the first and / or second receiver arrays (RA1, RA2) in order to provide acoustic pulses (AP) with operating times in one direction partially against and in the other direction partially along the flow direction (DF) of the gaseous medium (M).

11. Device (1) according to any one of claims 1 to 8, characterized in that the first transmitter arrangement (TA1) is adapted to be operated on demand as a second receiver arrangement (RA2) comprising the same components as the first receiver arrangement (RA1) required to also receive the acoustic pulse (AP) and in that the first receiver arrangement (RA1) is adapted to be operated on demand as a second transmitter arrangement (TA2) comprising the same components as the first transmitter arrangement (TA1) required to also transmit the acoustic pulse (AP), in that the first transmitter and receiver arrangements are arranged at different heights relative to the flow direction (DF) of the gaseous medium (M), in that the first transmitter arrangement (TA1) is adapted to transmit acoustic pulses (AP) at different times from the second transmitter arrangements (TA2) in order to provide acoustic pulses (AP) with operating times in one direction. Petition 870260036120, dated 17 / 04 / 2026, p.30 / 33 5 / 7 partially against and in the other direction partially along the flow direction (DF) of the gaseous medium (M).

12. Installation (100) for cement production, characterized by comprising at least one device (1) as defined in any of claims 1 to 11.

13. Method (200) for operating a device (1) as defined in any one of claims 1 to 11 at least for an acoustic temperature measurement in a gaseous medium passing through a medium channel (110) by means of time-operation measurement of an acoustic pulse (AP) flowing through the gaseous medium (M) from at least one first transmitter arrangement (TA1) arranged on one side of a medium channel (110) to at least one first receiver arrangement (RA1) arranged on the other side of the medium channel (110), characterized by comprising steps of: - generating (210) the acoustic pulse (AP) by a sound pulse generator (2);- transmit (220) the acoustic pulse (AP) by means of a first acoustic channel connected (3) to a transmitter (4), which transmits the acoustic pulse (AP) into the interior of the medium (M), wherein the first acoustic channel (3) is of acoustically dispersive design and is curved in the direction of the sound pulse generator (2) in such a way that the radiant heat of the medium (M) on the sound pulse generator (2) is at least enormously reduced; - detect (230) a retroreflected part (RI) of the acoustic pulse (AP) by a second microphone arranged in the first transmitter arrangement (TA1), wherein at least the transmitter (4) comprises, on its side (41) facing the medium (M) to be measured, an interference element (42), which is configured as a ring or a suitable shape around the output of the transmitter (4), to retroreflect the part (RI) of the acoustic pulse (AP) to the first acoustic channel (3); - receive (240) the acoustic pulse (AP) after it has passed through the medium (M) via a receiver (5);- transmit (250) the acoustic pulse (AP) through a second acoustic channel (6) to a first microphone (7) to detect the acoustic pulse (AP); Petition 870260036120, dated 17 / 04 / 2026, page 31 / 33 6 / 7 - determine (260) an arrival time (AT) of the recorded acoustic pulses (AP) by a pulse discriminator (9) in a suitable manner and transmit them to an evaluation unit (10); - determine (270) the temperature of the medium (M) from the operating time of the acoustic pulse (AP) from the transmitter (4) to the receiver (5) by the evaluation unit (10) taking into account the arrival times (AT) determined by the pulse discriminator (9) and the acoustic pulses (RI, AI) detected by the first and second microphones (7, 8); - determine the operating time inside the transmitter (4) and receiver (5) by measuring the operating time (230) of the retroreflected part (PI) of the pulse by the interference elements (42) at the output of the transmitter (4).; 14. Method according to claim 13, characterized in that the device (1) comprises at least one second transmitter arrangement (TA2) comprising the same components as the first transmitter arrangement (TA1), wherein the first and second transmitter arrangements (TA1, TA2) are arranged on the same side of the medium channel (110) at different heights (H1, H2) relative to a flow direction (DF) of the gaseous medium (M), wherein one of the first and second transmitter arrangements (TA1, TA2) is arranged above the first receiver arrangement (RA1) and the other is arranged below the first receiver arrangement (RA1) relative to the flow direction (DF) of the gaseous medium (M), comprising the step of generating and transmitting (280) acoustic pulses (AP) towards the receiver (5) at different times by the transmitter arrangements (TA1, TA2), and / or at least one second receiver arrangement (RA2) comprising the same components as the first receiver arrangement (RA1), wherein the first and second receiver arrangements (RA1,RA2) are arranged on the same side of the medium channel (110) at different heights (H1, H2) relative to the flow direction (DF) of the gaseous medium (M), wherein one of the first and second receiver arrangements (RA1, RA2) is arranged above the first transmitter arrangement (TA1) and the other is arranged below the first receiver arrangement (RA1) relative to the flow direction (DF) of the gaseous medium (M) comprising the steps of generating and transmitting (290) the acoustic pulses (AP) by the transmitter (4) either to the first or to the second receiver arrangement (RA1, RA2) and receiving the acoustic pulse (AP) from the transmitter (4) at different times by both receiver arrangements (RA1,RA2); and / or the first transmitter arrangement (TA1) is adapted to be operated on demand as a second receiver arrangement (RA2) comprising the same components as the first receiver arrangement (RA1) required to also receive the acoustic pulse (AP) and wherein the first receiver arrangement (RA1) is adapted to be operated on demand as a second transmitter arrangement (TA2) comprising the same components as the first transmitter arrangement (TA1) required to also transmit the acoustic pulse (AP), wherein the first transmitter and receiver arrangement are arranged at different heights relative to the flow direction (DF) of the gaseous medium (M), comprising the step (300) of generating and transmitting acoustic pulses from both transmitters (TA1, TA2) to both receivers (RA1, RA2) at different times; and calculating (310) a volume flow of the gaseous medium (M) through the medium channel (110) from a difference of both detected operating times,one partially against and one partially along the flow direction (DF) of the gaseous medium (M) by the evaluation unit (10)., 15. Method according to claim 14, characterized in that the steps of the method are followed by the calculation (320) of a gas enthalpy from the temperature and volume flow by the evaluation unit (10). Petition 870260036120, dated 17 / 04 / 2026, p. 33 / 33

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