Method and apparatus for measuring sound velocity in fluid product contained in pipe

Abstract

A method (200) for measuring the velocity of sound in a fluid product contained within a pipe (2), the method (200) comprising a main cycle comprising, in turn, at least the following steps cyclically performed at least once:-emitting a plurality of ultrasonic signals (201) towards the fluid product through a plurality of emission points (21) arranged along the pipe (2); -receiving a plurality of ultrasonic signals (202) through a plurality of receiving points (22) arranged along the pipeline (2); -measuring the time of flight (207) of the selected set of ultrasonic signals received at the receiving point (22) and calculating a sound velocity value (208); -at the end of the main cycle, calculating an average sound velocity (209).

Description

Technical Field

[0001] This invention relates to a method and apparatus for measuring the velocity of sound in a fluid product contained within a pipeline.

[0002] The invention presented herein has applications in the food industry, particularly in the dairy sector, or in the chemical, pharmaceutical, or cosmetic industries. This invention can also be applied to manufacturing processes that incorporate homogenization as a production step.

[0003] For example, the production of carbon-based nanostructured materials, such as graphene and carbon nanotubes, or the disruption of yeast, algae, or microbial cells could be considered for the production of intracellular substances. Background Technology

[0004] As is well known, homogenization equipment includes a high-pressure pump and a homogenization valve. The homogenization valve acts on the fluid product to:

[0005] - Break up the fluid particles to make the particle size uniform, reduce the average particle size and distribution variance, so as to stabilize the product and increase the product shelf life in emulsion scenarios;

[0006] - To break down cell membranes in order to facilitate the extraction of active ingredients in pharmaceutical applications;

[0007] – To alter the structure of particles in chemical applications and in scenarios involving cellulose or single-celled organisms.

[0008] For most products, the main parameters that define the level of homogenization are the average particle size and standard deviation.

[0009] In the known schemes, the pressure of the homogenization equipment is adjusted as described below.

[0010] First, the optimal average particle size and standard deviation for a given fluid product are determined experimentally. Then, the pressure required to obtain the calculated parameters for the particles is applied. The pressure is maintained using any of the following methods:

[0011] – The pressure value is adjusted periodically through manual intervention;

[0012] – Use a feedback system to take the pressure level detected in the received fluid product as input and drive the output to follow the setpoint.

[0013] Both methods act directly on the homogenization pressure.

[0014] However, homogenization pressure cannot serve as a reliable real-time indicator of the actual level of homogenization. In reality, even when the pressure and fluid product are equal, different levels of homogenization can still be achieved, for example, due to changes caused by new products supplied to the equipment and / or by wear and tear on components.

[0015] Known methods cannot track differences in the fluid products supplied to homogenization equipment.

[0016] Furthermore, known methods do not take into account the changes in fluid products caused by non-ideal components.

[0017] These situations are typically addressed by designing a homogenization device that ensures the homogenization level is above a predetermined threshold corresponding to the most unfavorable conditions.

[0018] Having an oversized homogenizer increases the risk of certain components being subjected to mechanical stress, which may reduce their lifespan.

[0019] In addition, applying pressure values ​​higher than required will increase energy consumption.

[0020] Finally, applying pressure higher than required cannot guarantee the desired level of homogenization, as it leads to increased temperature, which can damage the fluid product. Some products may even be discarded due to heat damage.

[0021] Document EP1121973A1 discloses a system for monitoring dispersions generated in a dispersion unit, particularly for monitoring the degree of homogenization of the dispersions, which proposes to couple a measurement sensor to the dispersion unit to achieve online measurement of the degree of homogenization of the dispersions.

[0022] The sensors used in this document may be ultrasonic sensors that are immersed in or in contact with fluid products. Therefore, these sensors are susceptible to contamination and are unreliable. Furthermore, they are easily damaged by the high temperature or pressure of the fluid product, or by corrosive chemicals used in in-situ cleaning (CIP) and steam in-situ (SIP) processes.

[0023] Depending on the application, known methods and devices for measuring the properties of fluid products are based on different types of sensors.

[0024] Document US5,473,934 discloses a known method and apparatus for continuously monitoring the composition of a fluid mixture flowing through a conduit. The relative component concentration of a liquid / liquid or solid / liquid fluid mixture is monitored using a non-invasive ultrasonic device. The relative component concentration of the fluid mixture is determined by measuring ultrasonic propagation parameters and temperature, and comparing these measurements with calibration data from sample analysis of the process fluid mixture.

[0025] Alexander L. Bowler, Serafim Bakalis, and Nicholas J. Watson's article, "Monitoring Mixing Processes Using Ultrasonic Sensors and Machine Learning," published in *Sensors*, 2020, Vol. 20, No. 7, p. 1813, is available at [link missing]. A system based on fluid acoustic impedance measurement is disclosed in scientific literature.

[0026] Bernd Henning and Jens Rautenberg reviewed ultrasonic methods for monitoring liquid mixture processes in their scientific paper, "Process monitoring using ultrasonic sensor systems," published in Ultrasonics, December 22, 2006, Volume 44, Supplement, pp. e1395-e1399.

[0027] It is still believed that it is necessary to increase the accuracy, reliability, real-time data processing, and adaptability to changes in operating conditions of fluid products in both static and dynamic states. Summary of the Invention

[0028] Against this backdrop, the object of the present invention is to provide a method and apparatus for measuring the velocity of sound in a fluid product contained in a pipeline, which overcomes the problems of the prior art described above.

[0029] In particular, the present invention aims to provide a method and apparatus for measuring the velocity of sound in a fluid product contained in a pipeline, which achieves higher measurement reliability than known solutions and can perform high-precision real-time operation on any type of fluid product.

[0030] Another object of the present invention is to provide a method and apparatus for measuring the velocity of sound in a fluid product contained in a pipeline, wherein the method and apparatus do not affect the fluid product.

[0031] Another object of the present invention is to provide a device for measuring the velocity of sound in a fluid product contained in a pipe, the device being robust in structure, resistant to wear over time, and easy to clean.

[0032] Another object of the present invention is to provide a device for measuring the velocity of sound in a fluid product contained in a pipeline, which can more efficiently formulate preventive maintenance operations.

[0033] The aforementioned technical tasks and specified objectives are substantially achieved through a method for measuring the velocity of sound in a fluid product contained within a pipeline, the method comprising a main loop, the main loop sequentially including the following steps performed at least once:

[0034] - Multiple ultrasonic signals are emitted toward the fluid product, allowing the ultrasonic signals to pass through the fluid product. The ultrasonic signals are emitted from multiple emission points set along the pipeline.

[0035] - After multiple ultrasonic signals pass through the fluid product, multiple ultrasonic signals are received. The ultrasonic signals are received by multiple receiving points set along the pipeline. The number of receiving points is the same as the number of transmitting points.

[0036] – Select the group of ultrasonic signals received at the receiving point;

[0037] – For each selected ultrasonic signal in a group of ultrasonic signals, measure the flight time from the corresponding transmitter point to the corresponding receiver point;

[0038] – For each selected ultrasonic signal in the group of ultrasonic signals, calculate the speed of sound, which is the ratio between the propagation distance of the ultrasonic signal from the corresponding transmission point to the corresponding reception point and the measured flight time.

[0039] At the end of the main loop, the method proceeds to the step of calculating the average sound speed, which is the average of at least a portion of the sound speed values ​​calculated in the main loop.

[0040] In one application of the invention, the pipeline is arranged downstream of the high-pressure homogenizer, such that the method is performed on the fluid product from the high-pressure homogenizer.

[0041] According to one aspect of the invention, the average sound speed is the arithmetic mean of some or all sound speed values ​​calculated in the main cycle.

[0042] Preferably, the ultrasonic signal is emitted synchronously from multiple emission points.

[0043] In one embodiment of the invention, the main loop further includes the step of amplifying the ultrasonic signal after receiving the ultrasonic signal at the receiving point.

[0044] Specifically, the step of amplifying the ultrasonic signal involves increasing the gain of the ultrasonic signal over time.

[0045] For example, the method includes the step of measuring the amplitude of each ultrasonic signal after it is emitted from the corresponding emission point, and performing an amplification step in response to the measured amplitude being lower than a minimum value.

[0046] According to one aspect of the invention, the step of selecting a group of ultrasonic signals includes detecting any faults in the ultrasonic signals received at the receiving point, and selecting the appropriate ultrasonic signal in response to the absence of any faults detected.

[0047] Specifically, the steps for selecting a group of ultrasound signals include:

[0048] – Measure the amplitude of each ultrasonic signal received at the corresponding receiving point;

[0049] -In response to the measured amplitude being within the predetermined acceptable range, the appropriate ultrasonic signal is selected;

[0050] - In response to the measured amplitude exceeding the predetermined acceptable range, the corresponding ultrasonic signal is rejected.

[0051] According to one embodiment of the so-called transmission configuration of the invention, the transmitting points are distributed along one side of the pipe, and the receiving points are distributed along the opposite side of the pipe relative to the fluid product. A transmitter is arranged at each transmitting point, consisting of an ultrasonic sensor configured to transmit ultrasonic signals; similarly, a receiver is arranged at each receiving point, consisting of an ultrasonic sensor configured to receive ultrasonic signals.

[0052] In this embodiment, the propagation distance of each ultrasonic signal from its corresponding transmitting point to its corresponding receiving point is the distance between the transmitter that transmits the ultrasonic signal and the corresponding receiver that receives the ultrasonic signal.

[0053] According to another embodiment of a so-called pulse-echo configuration, each transmitting point coincides with one of a plurality of receiving points to create a transceiver point. The transceiver points are distributed along the same side of the pipe. An ultrasonic transducer is arranged at each transceiver point, configured to transmit and receive ultrasonic signals. The ultrasonic signals emitted by the ultrasonic transducers are reflected back by reflective devices arranged on the opposite side of the pipe relative to the fluid product.

[0054] In this embodiment, the propagation distance of each ultrasonic signal from the corresponding transmitting point to the corresponding receiving point is twice the distance between the ultrasonic transducer and the reflecting device.

[0055] According to one aspect of the invention, the method further includes a dimensional measurement program, which is executed before the main loop of the method is started.

[0056] The dimensional measurement procedure includes calculating the thickness of the pipe and the propagation distance of the ultrasonic signal from the corresponding transmitting point to the corresponding receiving point.

[0057] Specifically, in one embodiment (pulse-echo configuration), calculating the thickness of the pipe includes at least the following steps:

[0058] – Measure the velocity of sound at different temperatures in a predetermined sample made of the same material as the pipe;

[0059] – Measure the flight time inside the pipe in an empty state, which means there is no fluid inside the pipe;

[0060] - Detect the temperature of the pipeline;

[0061] – The thickness of the pipe is calculated by multiplying the speed of sound measured at the detection temperature by the time of flight measured inside the pipe.

[0062] In a pulse-echo configuration, calculating the propagation distance of the ultrasonic signal from the corresponding transmitter to the corresponding receiver includes an initial loop, which sequentially includes the following steps executed at least once:

[0063] - Multiple ultrasonic signals are emitted toward a selected fluid product in the pipeline, such that the ultrasonic signals pass through the selected fluid product, and the ultrasonic signals are emitted from multiple emission points;

[0064] - Receives multiple ultrasonic signals after the fluid product passes through it, and the ultrasonic signals are received by multiple receiving points;

[0065] – Detect any faults in the ultrasonic signal received at the receiving point;

[0066] - For each of the multiple ultrasonic signals, in response to the absence of any fault detected, measure the flight time from the corresponding transmitter point to the corresponding receiver point;

[0067] For each of the multiple ultrasonic signals, in response to the absence of any fault detected, calculate the propagation distance of the ultrasonic signal from the corresponding emission point to the corresponding receiving point. The propagation distance is the sum of the pipe thickness and the pipe inner diameter.

[0068] At the end of the initial cycle, the dimensional measurement procedure further includes a step of calculating an average distance, which is the average of at least a portion of the propagation distance calculated in the initial cycle.

[0069] Calculating the propagation distance of an ultrasonic signal from the corresponding emission point to the corresponding receiving point further includes the step of measuring the velocity of sound of a selected fluid product at different temperatures, which is performed before the initial cycle.

[0070] Specifically, the average distance is the arithmetic mean of some or all of the distances calculated in the initial loop.

[0071] The aforementioned technical tasks and specified objectives are substantially achieved by a device for measuring the velocity of sound in a fluid product contained within a pipeline, the device comprising:

[0072] – A pipe having an internal cavity for the passage of fluid products, the internal cavity having a variable diameter across the length of the pipe;

[0073] - Multiple ultrasonic transmitters are mounted on a plate in the pipe and configured to emit ultrasonic signals;

[0074] - Multiple ultrasonic receivers are mounted on a plate on the pipe and located outside the internal cavity. The ultrasonic receivers are distributed along the length of the pipe and configured to detect ultrasonic signals. The number of ultrasonic receivers is the same as the number of ultrasonic transmitters.

[0075] The device further includes a control unit configured as follows:

[0076] - Command the ultrasonic transmitter to emit multiple ultrasonic signals toward the fluid product, so that the ultrasonic signals pass through the fluid product;

[0077] - Command the ultrasonic receiver to receive multiple ultrasonic signals emitted by the ultrasonic transmitter after multiple ultrasonic signals have passed through the fluid product;

[0078] - Select the group of ultrasonic signals received by the ultrasonic receiver;

[0079] - For each selected ultrasonic signal in a group of ultrasonic signals, measure the flight time from the corresponding ultrasonic transmitter to the corresponding ultrasonic receiver.

[0080] - For each selected ultrasonic signal in the group of ultrasonic signals, calculate the speed of sound, which is the ratio between the propagation distance of the ultrasonic signal from the corresponding ultrasonic transmitter to the corresponding ultrasonic receiver and the measured time of flight.

[0081] - Calculate the average sound speed, which is the average of at least a portion of the calculated sound speed values.

[0082] Preferably, the control unit is further configured to amplify the ultrasonic signal after the ultrasonic receiver receives the ultrasonic signal.

[0083] According to one embodiment of the present invention, the pipeline includes:

[0084] –Outer tube;

[0085] -Inner tube, coaxially arranged inside the outer tube, the inner tube has an inner surface that defines the internal cavity;

[0086] Multiple housings are located on the outer surface of the inner tube, with each ultrasonic receiver arranged in one of the housings. Attached Figure Description

[0087] As illustrated in the accompanying drawings, additional features and advantages of the invention will become clearer from a non-limiting description of a preferred, but not exclusive, embodiment of a method and apparatus for measuring the velocity of sound in a fluid product within a pipe, wherein: Figure 1 and Figure 2 Partial cross-sectional views of an apparatus for measuring the velocity of sound in a fluid product within a pipeline, according to two different embodiments of the present invention, are shown.

[0088] – Figure 3 The use of a device according to the invention for online measurement of the velocity of sound in a fluid product from a dispersion unit is illustrated;

[0089] – Figure 4 This is a schematic diagram of the device according to the present invention;

[0090] – Figure 5a and Figure 5b A flowchart of a method for measuring the velocity of sound in a fluid product within a pipeline, according to the present invention, is shown.

[0091] – Figure 6a and Figure 6b A flowchart of the dimensional measurement procedure according to the method of the present invention is shown;

[0092] – Figure 7a and Figure 7b Two different curves showing gain amplification over time are presented, exhibiting linear and logarithmic development, respectively.

[0093] – Figure 8 The trend curve for the reference fluid product is shown. Detailed Implementation

[0094] Reference numeral 1 in the attached figure indicates an apparatus for measuring the velocity of sound in a fluid product. In particular, apparatus 1 can measure the velocity of sound in a fluid product under static or dynamic conditions.

[0095] In one application, device 1 is used to measure the velocity of sound in a fluid product from dispersion unit 100 online.

[0096] In a preferred embodiment, the dispersion unit 100 is a high-pressure homogenizer, which includes a positive displacement piston pump and a homogenizing valve arranged downstream of the positive displacement piston pump.

[0097] In particular, the high-pressure homogenizer 100 operates at pressures up to 4000 bar.

[0098] The dispersion unit 100 has an inlet 100a for the fluid to be homogenized and an outlet 101b for the homogenized fluid product.

[0099] Equipment 1 includes pipe 2, which has an inlet 2a and an outlet 2b for fluid products. Pipe 2 has a longitudinal axis, denoted as AA.

[0100] exist Figure 3 In this embodiment, the pipe 2 is arranged downstream of the dispersion unit 100. Specifically, the inlet 2a of the pipe 2 is in fluid communication with the outlet 100b of the dispersion unit 100 in order to receive homogenized fluid products from the dispersion unit 100.

[0101] The pipe 2 has an internal cavity 3 for receiving fluid products from the dispersion unit 100.

[0102] The internal cavity 3 extends from the inlet 2a of the pipe 2 to the outlet 2b.

[0103] The diameter of the internal cavity 3 at the inlet 2° and the outlet 2b of the pipe 2 is basically the same.

[0104] Initially, the internal cavity 3 has a variable diameter spanning the length of the pipe 2.

[0105] Specifically, the internal cavity 3 has at least one first section 31 that extends in a conical shape from the inlet 2a of the pipe 2 toward the outlet 2b.

[0106] In other words, the first section 31 has a converging shape from the inlet 2a of the pipe 2 toward the outlet 2b.

[0107] In particular, the tapered development of the first section 31 is discrete, which means that the diameter of the first section 31 decreases in discrete steps from the inlet 2a of the pipe 2 toward the outlet 2b.

[0108] Preferably, the first section 31 of the internal cavity 3 is formed by a plurality of generally cylindrical portions 310, which are connected by truncated conical portions 311.

[0109] The cylindrical portion 310 has a corresponding diameter that decreases from the inlet 2a of the pipe 2 toward the outlet 2b.

[0110] exist Figure 1 and Figure 2 In the illustrated embodiment, the first segment 31 includes five cylindrical portions 310 connected by four truncated conical portions 311.

[0111] The internal cavity 3 preferably has a second section 32 that starts from the first section 31 and ends at the outlet 2b of the pipe 2.

[0112] The second section 32 has a tapered development from the outlet 2b of the pipe 2 toward the first section 31.

[0113] In other words, the second section 32 has a converging shape from the outlet 2b of the pipe 2 toward the first section 31.

[0114] Specifically, the second section 32 is composed of a truncated conical portion 321, which connects the first section 31 to the outlet 2b of the pipe 2.

[0115] Specifically, the last cylindrical portion 310 of the first section 31 is connected to the truncated conical portion 321 of the second section 32.

[0116] The device 1 further includes a plurality of ultrasonic transducers 4 configured to detect at least ultrasonic signals.

[0117] As will be explained later, in one embodiment of the method proposed in this invention (referred to as "transmission type"), the electronic transducer 4 is configured only to detect (i.e. receive) ultrasonic signals.

[0118] In another embodiment of the method proposed in this invention (referred to as "pulse-echo type"), the electronic transducer 4 is configured to transmit and receive ultrasonic signals.

[0119] In this article, ultrasonic signal and ultrasonic wave are synonyms.

[0120] The ultrasonic transducer 4 is mounted on the plate of pipe 2.

[0121] Specifically, the ultrasonic transducers 4 are distributed along the length of the pipe 2.

[0122] Preferably, the ultrasonic transducers 4 are evenly spaced along the length of the pipe 2.

[0123] According to one embodiment of the invention, the distance between two consecutive ultrasonic transducers 4 along the pipe 2 is between 30 mm and 60 mm. In particular, the distance between the two consecutive ultrasonic transducers 4 is selected to avoid interference problems.

[0124] Preferably, each ultrasonic transducer 4 is configured to receive ultrasonic waves with frequencies ranging from 0.5 MHz to 20 MHz.

[0125] More preferably, each ultrasonic transducer 4 is configured to receive ultrasonic waves with frequencies ranging from 2 MHz to 10 MHz.

[0126] Specifically, the choice of the operating frequency range depends on the acoustic impedance of the fluid product. In fact, the operating frequency of the ultrasonic transducer 4 is selected in order to detect ultrasonic waves passing through a specific fluid product with a specific acoustic impedance.

[0127] In a preferred embodiment, the ultrasonic transducer 4 is a piezoelectric ceramic sensor.

[0128] In a preferred embodiment, all ultrasonic transducers 4 are identical.

[0129] In an alternative embodiment, the ultrasonic transducer 4 may vary in size and / or signal frequency and / or signal amplitude.

[0130] According to the illustrated embodiment, pipe 2 includes an inner pipe 5 and an outer pipe 6.

[0131] The inner tube 5 and the outer tube 6 are coaxial and are arranged inside the outer tube 6.

[0132] The inner tube 5 defines the internal cavity 3. Specifically, the internal cavity 3 is defined by the inner surface 5a of the inner tube 5.

[0133] Specifically, the inner surface 5a of the inner tube 5 has an initial portion that tapers from the inlet 2a of the pipe 2 toward the outlet 2b, so as to define the corresponding taper development of the first section 31 of the inner cavity 3.

[0134] In particular, the tapered development of the initial portion of the inner surface 5a is discrete, which means that the inner diameter of the inner tube 5 in the initial portion decreases discretely from the inlet 2a toward the outlet 2b.

[0135] The last part of the inner surface 5a of the inner tube 5 has an anti-conical development relative to the first part, so as to define the corresponding second section 32 of the inner cavity 3.

[0136] Preferably, the inner tube 5 is made of plastic material. Therefore, ultrasonic signals can pass through the inner tube 5.

[0137] More preferably, the inner tube 5 is made of PEEK.

[0138] Alternatively, the inner tube 5 is made of PTFE.

[0139] exist Figure 1 and Figure 2 In the illustrated embodiment, the ultrasonic transducer 4 is arranged between the inner tube 5 and the outer tube 6.

[0140] Specifically, the inner tube 5 has multiple housings 7 for receiving ultrasonic transducers 4.

[0141] Preferably, the housing 7 is formed as an inward groove on the outer surface 5b of the inner tube 5.

[0142] Specifically, each housing 7 is associated with one of the cylindrical portions 310 of the first segment 31.

[0143] The ultrasonic transducer 4 is positioned on the inner tube 5, but not facing the inner cavity 3, to avoid direct contact with the fluid product flowing within the inner cavity 3. This arrangement also introduces a delay in the received ultrasonic signal, which is generated by the material of the inner tube 5.

[0144] Speaking of signals, tube 5 represents the delay line.

[0145] According to one aspect of the invention, the ultrasonic transducer 4 is glued to the inner tube 5. In particular, the ultrasonic transducer 4 is disposed inside the housing 7 and glued to the outer surface 5b of the inner tube 5.

[0146] According to another embodiment (not shown), the ultrasonic transducer 4 is mounted on the outer surface of the pipe 2.

[0147] For example, the ultrasonic transducer 4 is threaded to the outside of the pipe 2.

[0148] Specifically, the ultrasonic transducer 4 is mounted to the outside of the outer tube 6. For example, the ultrasonic sensor 4 is threaded to the outside of the outer tube 6 so as to be close to the inner tube 5.

[0149] Preferably, in this embodiment, an ultrasonic gel is provided between the ultrasonic transducer 4 and the inner tube 5 to ensure the transmission of ultrasonic signals.

[0150] Reference numeral 200 indicates a method for measuring the velocity of sound in a fluid product within a pipe, such as the pipe 2 of the device 1 described above.

[0151] Preferably, method 200 is implemented using the device 1 proposed in this invention.

[0152] Alternatively, method 200 may be implemented using other devices different from the device 1 proposed in this invention.

[0153] Method 200 includes executing the main loop step once or multiple times.

[0154] Preferably, the main cycle of method 200 is initiated by emitting multiple ultrasonic signals toward the fluid product within pipe 2, such that the ultrasonic signals pass through the fluid product. This emission step is indicated by reference numeral 201.

[0155] Specifically, ultrasonic signals are emitted by multiple emission points 21 arranged along the pipe 2.

[0156] Preferably, the ultrasonic signal is emitted synchronously from multiple emission points 21.

[0157] After the ultrasonic signal passes through the fluid product, it is received by a plurality of receiving points 22 arranged along the pipe 2. This receiving step is indicated by reference numeral 202.

[0158] Specifically, the number of receiving points 22 is the same as the number of transmitting points 21. Preferably, each of the plurality of transmitting points 21 is coupled to a corresponding receiving point 22 of the plurality of receiving points 22.

[0159] According to an embodiment called "pulse echo", each transmitting point 21 coincides with one of a plurality of receiving points 22 in order to generate a transceiver point.

[0160] In other words, in a pulse-echo configuration, each transceiver point acts as both a transmitter and a receiver.

[0161] The receiving and dispatching points are distributed along one side of pipe 2. In particular, the receiving and dispatching points are distributed along the same side of pipe 2 relative to the fluid product.

[0162] A transceiver is placed at each transceiver point. The transceiver consists of an ultrasonic transducer configured to transmit and receive ultrasonic signals.

[0163] The ultrasonic signal is emitted by an ultrasonic transducer located on one side of the pipe 2. The ultrasonic signal emitted by the ultrasonic transducer is reflected back by a reflector arranged on the opposite side of the pipe 2 relative to the fluid product.

[0164] Referring to the device 1 proposed in this invention, the ultrasonic transducer 4 is configured as a transceiver in a pulse-echo configuration. In particular, the ultrasonic transducer 4 of device 1 is configured to transmit and receive ultrasonic signals.

[0165] like Figure 1 The illustrated embodiment.

[0166] Preferably, each cylindrical portion 310 of the first section 31 of the internal cavity 3 is coupled to one of the ultrasonic transducers 4. Each ultrasonic transducer 4 is arranged in one of the housings 7 obtained in the inner tube 5.

[0167] The sound waves generated by the ultrasonic transducer 4 pass through the fluid product in the internal cavity 3 and are reflected back by the inner surface 5a of the inner tube 5. Preferably, the inner surface 5a is made of metal.

[0168] In this case, the inner surface 5a of the inner tube 5 constitutes a reflective device.

[0169] Alternatively, the reflecting device includes a plurality of reflecting elements mounted on the opposite side of the housing 7 relative to the internal cavity 3.

[0170] According to another embodiment, referred to as "transmissive",

[0171] The emission point 21 is distributed along one side of the pipe 2, and the receiving point 22 is distributed along the opposite side of the pipe 2 relative to the fluid product.

[0172] Each of the 21 transmitters is equipped with an ultrasonic sensor configured to transmit ultrasonic signals.

[0173] Each receiving point has 22 receivers, each consisting of an ultrasonic sensor configured to receive ultrasonic signals.

[0174] Referring to the device 1 proposed in this invention, in a transmissive configuration, the ultrasonic transducer 4 is configured to function solely as an ultrasonic receiver for ultrasonic signals.

[0175] Therefore, the ultrasonic transducer 4 is also called an "ultrasonic receiver" for transmission configuration.

[0176] like Figure 2 The illustrated embodiment.

[0177] In this embodiment, device 1 further includes a group of ultrasonic transmitters 14 configured to serve as transmitters of ultrasonic signals.

[0178] Preferably, each cylindrical portion 310 of the first section 31 of the internal cavity 3 is coupled to one of the ultrasonic receivers 4 and to one of the ultrasonic transmitters 14.

[0179] Preferably, each ultrasonic receiver 4 is arranged inside one of the housings 7 obtained in the inner tube 5.

[0180] Preferably, the ultrasonic transmitter 14 is arranged between the inner tube 5 and the outer tube 6, and is located within a plurality of additional housings 17 obtained in the inner tube 5.

[0181] The additional housing 17 for the ultrasonic transmitter 14 has an inwardly recessed outer surface 5b of the inner tube 5 and is positioned opposite the housing 7 for the ultrasonic receiver 4 relative to the inner cavity 3.

[0182] The sound waves generated by the ultrasonic transmitter 14 pass through the fluid product in the internal cavity 3 and are detected by the ultrasonic receiver 4.

[0183] After receiving step 202, the main loop of method 200 executes the step of selecting the group of ultrasonic signals received at receiving point 22. This step is indicated by reference numeral 203.

[0184] In one embodiment, any fault included in the ultrasonic signal received at receiving point 22 is selected, and in response to the absence of any fault, the corresponding ultrasonic signal is selected.

[0185] Preferably, the fault is related to the amplitude of the ultrasonic signal exceeding the predetermined acceptable range.

[0186] Specifically, selection step 203 includes measuring the amplitude of each ultrasonic signal received at the corresponding receiving point 22. This step is indicated by reference numeral 204.

[0187] For example, the amplitude is measured by the peak detector of device 1.

[0188] A measured amplitude within the predetermined acceptable range means that no fault has been detected. Therefore, in response to the measured amplitude being within the predetermined acceptable range, an appropriate ultrasonic signal is selected. This step is indicated by reference numeral 205 in the attached figure.

[0189] Conversely, if the measured amplitude exceeds the predetermined acceptable range, it means a fault has been detected. Therefore, in response to the measured amplitude exceeding the predetermined acceptable range, the corresponding ultrasonic signal is rejected, which means no selection is made. This step is indicated by reference numeral 206 in the attached figure.

[0190] For alternative or additional ground fault detection, step 203 can be performed using known gating techniques.

[0191] For each selected ultrasonic signal in the group of ultrasonic signals, the main loop performs the step of measuring the flight time of the ultrasonic signal from the corresponding transmission point 21 to the corresponding reception point 22. This step is indicated by reference numeral 207.

[0192] In practice, the flight time is measured for all selected ultrasonic signals received at the corresponding receiving point 22.

[0193] In this paper, time of flight is also referred to as propagation time, and is denoted by the symbol t. F express.

[0194] The time of flight of a signal is the time required for the signal to travel from the transmitter to the receiver.

[0195] The flight time t of the selected ultrasonic signal was measured. F Then, the speed of sound is calculated; the speed of sound is the ratio of the propagation distance of the ultrasonic signal to the measured flight time t. F The ratio. This step is indicated by reference numeral 208 in the attached figure.

[0196] Specifically, the propagation distance of the ultrasonic signal is the distance from the corresponding transmitting point 21 to the corresponding receiving point 22, denoted by the symbol d.

[0197] In practice, the sound velocity value is calculated for all selected ultrasonic signals.

[0198] The speed of sound is represented by the symbol v. S express.

[0199] For each selected ultrasonic signal, the sound velocity value is calculated using the following formula:

[0200] (1)

[0201] In the pulse-echo configuration, the propagation distance of each ultrasonic signal from the corresponding transmitting point 21 to the corresponding receiving point 22 is twice the distance between the ultrasonic transducer 4 and the reflecting device, specifically the inner surface 5a of the inner tube 5. This is because the ultrasonic transducer 4 is configured to transmit and receive ultrasonic signals reflected back from the inner surface 5a.

[0202] In a transmissive configuration, the propagation distance of each ultrasonic signal from the corresponding transmitting point 21 to the corresponding receiving point 22 is the distance between the ultrasonic transmitter 14 that transmits the ultrasonic signal and the corresponding ultrasonic receiver 4 that receives the ultrasonic signal.

[0203] As mentioned above, the main loop steps can be repeated a predetermined number of times, which can be adjusted according to needs.

[0204] In pulse-echo configurations, multiple sound velocity values ​​are typically calculated for each transmit and receive point.

[0205] In a transmissive configuration, multiple sound velocity values ​​are typically calculated for each pair of transmitting points 21 and receiving points 22.

[0206] For example, when no fault is detected in the ultrasonic signal received at a given receiving point 22, the number of calculated sound velocity values ​​is consistent with the predetermined number of times the main loop step is executed.

[0207] When one or more faults are detected in the ultrasonic signals received at a given receiving point 22, the number of calculated sound velocity values ​​is less than the predetermined number of times the main loop steps are executed.

[0208] When the main loop ends, method 200 further includes the step of calculating the average speed of sound. This step is indicated by reference numeral 209.

[0209] Specifically, step 209 of calculating the average sound speed includes calculating the average of at least a portion of the sound speed values ​​calculated in the main loop.

[0210] In this paper, the average sound speed is the arithmetic mean of some or all sound speed values ​​calculated in the main loop.

[0211] In one embodiment of the invention, the average speed of sound is calculated using all the speed of sound values ​​calculated in the main loop.

[0212] In the illustrated embodiment, there are four transmitting points 21 and four receiving points 22.

[0213] Assuming the main loop steps are repeated at least 32 times, the calculated speed of sound is 128 if no fault is detected, or less than 128 if a fault is detected.

[0214] The average value is calculated based on a sound speed value of 128 (or less).

[0215] For example, only the last 20 calculated sound speed values ​​are used for averaging.

[0216] In the device 1 proposed in this invention, each of the calculated sound velocity values ​​refers to one of the cylindrical portions 310 of the first segment 31. Since the cylindrical portions 310 have different diameters, the fluid product has a different velocity in each portion.

[0217] The velocity of fluid products affects the measurement of flight time, thus introducing errors.

[0218] Measuring time of flight at sections with different diameters (i.e., different cross-sections) introduces errors of varying magnitudes. The relationship between time-of-flight error and fluid velocity is non-linear and depends particularly on the characteristics of the fluid product.

[0219] Calculating the average sound velocity for cylindrical sections 310 with different diameters can increase accuracy because the average value is not affected by the specific dimensions of the internal cavity 3.

[0220] With variable flow rates, measurement accuracy can be further increased.

[0221] According to one aspect of the invention, the main loop further includes the step of amplifying the ultrasonic signal after receiving the ultrasonic signal at the receiving point 22. This step is indicated by reference numeral 250.

[0222] Specifically, amplification is performed by increasing the gain of the ultrasonic signal over time.

[0223] For example, amplification is based on a lookup table or a curve showing how the gain coefficient changes over time. Specifically, the gain coefficient increases over time. Figure 7a The curve showing the gain coefficient has a linear development over time is shown, therefore Figure 7b Curves showing logarithmic growth over time are shown. These are just examples; other gain magnitude curves may also be used.

[0224] Preferably, amplification is performed only on ultrasonic signals that are attenuated too much and cannot be detected at the receiving point 22.

[0225] Specifically, before step 250 of amplifying the ultrasonic signal, a step of measuring the amplitude of each ultrasonic signal is performed.

[0226] In response to the measured amplitude being lower than a predetermined minimum value, the corresponding ultrasonic signal is amplified.

[0227] Amplification is particularly advantageous in pulse-echo configurations because the reflected ultrasonic signal is significantly attenuated due to passing through the fluid product twice.

[0228] Amplification allows for an increase in the gain of the ultrasonic signal over time after reflection, avoiding the gain increase as the signal passes through the delay line. In fact, the material of the inner tube 5 (e.g., PEEK) does not attenuate the ultrasonic signal, or at least produces negligible attenuation; therefore, ultrasonic signals passing through PEEK do not require amplification. Amplification would pose a risk of signal saturation.

[0229] Amplification allows for an increase in the intensity of ultrasonic signals, which can sometimes be significantly weakened when passing through fluid products with high attenuation. Without amplification, the received ultrasonic signals would be too weak.

[0230] Preferably, the main cycle further includes the step of adjusting the ultrasonic signal after receiving the ultrasonic signal at the receiving point 22. This step is indicated by reference numeral 255.

[0231] The adjustment is preferably performed after amplifying the ultrasonic signal at step 250.

[0232] In one embodiment, the conditioning includes filtering noise.

[0233] In one embodiment, device 1 includes one or more of the following components for performing amplification and filtering: a bandwidth-adjustable low-noise amplifier, an ultra-low-noise preamplifier, and an amplifier with a wide gain range and a programmable postamplifier (e.g., a VGA). These components are consistent and will not be described further herein.

[0234] In one embodiment, the analog gain for receiving is adjustable in 0.5 dB steps within the range of -31 dB to 65 dB.

[0235] To ensure high accuracy in calculating the velocity of sound in a fluid product using formula (1), the flight time must be precisely measured at each receiving point 22, and the exact propagation distance d of the ultrasonic signal from the corresponding transmitting point 21 to the corresponding receiving point 22 must be known.

[0236] Preferably, method 200 includes a dimension measurement procedure 210 executed before the main loop starts.

[0237] Since the receiving point 22 is located along the pipe 2 but does not come into contact with the fluid product, the time-of-flight measurement of the ultrasonic signal from the transmitting point 21 to the receiving point 22 will be affected by the delay introduced by the thickness of the pipe 2.

[0238] In a preferred embodiment, the receiving point 22 is located inside the housing 7 of the inner tube 5 of the pipe 2.

[0239] Therefore, the contribution of the material of the inner tube 5 (e.g., PEEK) to the total flight time should be identified and isolated.

[0240] The dimensional measurement procedure 210 includes calculating the thickness of the inner tube 5 and calculating the propagation distance d of the ultrasonic signal from the corresponding transmitting point 21 to the corresponding receiving point 22.

[0241] The dimensional measurement procedure 210 for pulse-echo configurations is detailed below. A similar procedure is used for transmissive configurations.

[0242] The step of calculating the thickness of the inner tube 5 to measure the sound velocity of a predetermined sample made of the same material as the inner tube 5 at different temperatures is initiated. This step is indicated by reference numeral 211 in the attached drawing.

[0243] Specifically, the intended sample is a PEEK planar parallel plate with known dimensions.

[0244] Step 211, which measures the velocity of sound in a predetermined sample, is performed using known methods and systems.

[0245] At the end of step 211, the velocity of sound (in v) is obtained for the material of the inner tube 5. S-delay (This represents a function curve that varies with temperature T).

[0246] Subsequently, the flight time within the inner tube 5 is measured in an empty state, meaning there is no fluid in the inner cavity 3. This step is indicated by reference numeral 212 in the attached drawing.

[0247] It should be noted that the ultrasonic waves emitted from the emission point 21 pass through the thickness of the inner tube 5 and are reflected back by the inner surface 5a due to the impedance difference between the medium in the inner tube 5 and the medium in the empty tube.

[0248] The temperature of the inner tube 5 is also detected, for example, by a temperature sensor applied to the inner tube 5. This step is indicated by reference numeral 213 in the attached drawing.

[0249] The thickness of the inner tube 5 (denoted by th) is then calculated using the inverse formula of formula (1), which in this case is:

[0250] (2)

[0251] In the formula, v S-delay The velocity of sound inside the inner tube 5 is obtained from the curve corresponding to a specific detection temperature, and v S-delay The measured flight time within the inner tube 5. Specifically, the flight time v. S-delay The measurement takes into account the reflection of the ultrasonic wave by the first inner surface 5a of the inner tube 5 upon encountering the sound wave. The steps for calculating the thickness of the inner tube are indicated by reference numeral 214 in the attached drawing.

[0252] After calculating the thickness th of the inner tube 5, the dimensional measurement program 210 continues to calculate the propagation distance d of the ultrasonic signal from the corresponding transmitting point 21 to the corresponding receiving point 22.

[0253] The step of calculating the distance d to measure the speed of sound of a selected (i.e., known) fluid product at different temperatures is initiated. This measurement is performed at different temperatures using known methods and systems, and is indicated by reference numeral 215 in the accompanying figure.

[0254] At the end of step 215, the velocity of sound (in v) is obtained for the selected fluid product. S-delay (This represents a function curve showing how temperature T changes.)

[0255] Subsequently, the initial loop steps are executed one or more times before the main loop of method 200.

[0256] Preferably, the initial cycle is initiated by emitting multiple ultrasonic signals toward a selected fluid product within pipe 2, such that the ultrasonic signals pass through the selected fluid product. This step is indicated by reference numeral 216.

[0257] The ultrasonic signal is emitted by multiple emission points 21 set along the pipe 2.

[0258] Preferably, the ultrasonic signal is emitted synchronously from multiple emission points 21.

[0259] After the ultrasonic signal passes through the selected fluid product, the ultrasonic signal is received by a plurality of receiving points 22 arranged along the pipe 2 (this is step 217).

[0260] Subsequently, the flight time of each ultrasonic signal from the corresponding transmitting point 21 to the corresponding receiving point 22 is measured. This step is indicated by reference numeral 219 in the attached figure.

[0261] As mentioned above, the flight time of the ultrasonic signal is affected by the delay in pipe 2.

[0262] In this paper, the flight time measured at step 219 is called the "total flight time" and is denoted as t. F .

[0263] Total flight time t F For the selected fluid product, the flight time (in t) F-fluid (Indicates) the flight time t within the inner tube 5 F-delay The sum of these. Therefore, the total flight time is:

[0264] (3)

[0265] Similarly, the distance d is the sum of the inner diameter ø of the inner tube 5 and the thickness th of the inner tube 5.

[0266] Therefore, the distance d can be calculated using the inverse formula of formula (1), which in this case is:

[0267] (4)

[0268] The steps for calculating distance d are indicated by reference numeral 220 in the attached figure.

[0269] The calculated distance d is used in the main loop to calculate the speed of sound at step 208.

[0270] In practice, the distance value is calculated for all ultrasonic signals for which no fault is detected at the corresponding receiving point 22.

[0271] As described above, in the pulse-echo configuration, the propagation distance d of each ultrasonic signal from the corresponding transmitting point 21 to the corresponding receiving point 22 is twice the distance between the ultrasonic transducer 4 and the reflecting device, particularly the inner surface 5a of the inner tube 5.

[0272] A similar procedure can be used in a transmissive configuration, where the propagation distance d of each ultrasonic signal from the corresponding transmitting point 21 to the corresponding receiving point 22 is the distance between the ultrasonic transmitter 14 that transmits the ultrasonic signal and the corresponding ultrasonic receiver 4 that receives the ultrasonic signal.

[0273] Preferably, the initial loop also includes detecting any faults in the ultrasonic signal received at the receiving point 22, a step indicated by reference numeral 218.

[0274] The fault detection step 218 is similar to the fault detection in the selection step 203 executed in the main loop of method 200.

[0275] Specifically, the fault detection step 218 includes the measurement amplitude step 204 of the ultrasonic signal, and in response to the measured amplitude being within or outside a predetermined acceptable range, confirming that no fault has been detected or that a fault has been detected (steps 205 and 206, respectively).

[0276] In response to the absence of a fault detected at receiving point 22, step 219 of measuring flight time is performed.

[0277] In other words, the flight time is measured for all ultrasonic signals for which no fault was detected at the corresponding receiving point 22.

[0278] As described above, the initial loop steps can be repeated a predetermined number of times, which can be adjusted as needed.

[0279] When no fault is detected in the ultrasonic signal received at receiving point 22, the number of calculated distance values ​​is consistent with the predetermined number of times the initial loop step is executed.

[0280] When one or more faults are detected in the ultrasonic signals received at receiving point 22, the number of calculated distance values ​​is less than the predetermined number of times the initial loop steps are executed.

[0281] When the initial loop ends, method 200 performs the step of calculating the average distance. This step is indicated by reference numeral 221 in the attached figure.

[0282] Specifically, the step 221 of calculating the average distance includes calculating the average of at least a portion of the distance values ​​calculated in the initial loop.

[0283] In this paper, the average distance is the arithmetic mean of some or all of the distance values ​​calculated in the initial loop.

[0284] After the initial loop finishes, the main loop of method 200 can start.

[0285] The device 1 further includes a temperature sensor 8, which is configured to detect the temperature of the pipe 2, particularly the inner pipe 5.

[0286] In addition, device 1 includes acquisition unit 9, which is configured to acquire ultrasonic signals received by ultrasonic receiver (for pulse echo or transmission type).

[0287] The acquisition unit 9 is connected to the control unit 10, which is configured to measure the velocity of sound in the fluid product within the pipe 2.

[0288] Specifically, the control unit 10 is configured to at least:

[0289] – Command the ultrasonic transmitter to emit multiple ultrasonic signals toward the fluid product in pipe 2, so that the ultrasonic signals pass through the fluid product;

[0290] – Command the ultrasonic receiver to receive multiple ultrasonic signals emitted by the ultrasonic transmitter and passing through the fluid product;

[0291] – Select the group of ultrasonic signals received by the ultrasonic receiver;

[0292] – For each selected ultrasonic signal in the group of ultrasonic signals, measure the flight time from the corresponding ultrasonic transmitter to the corresponding ultrasonic receiver.

[0293] - Calculate the sound velocity value for each selected ultrasonic signal in the group of ultrasonic signals;

[0294] - Calculate the average sound speed, which is the average of at least a portion of the calculated sound speed values.

[0295] In addition, the control unit 10 is configured to amplify the ultrasonic signal after the ultrasonic receiver receives the ultrasonic signal.

[0296] In addition, the control unit 10 is configured to calculate the thickness and distance d of the pipe 2 according to the dimensional measurement program 210.

[0297] The device 1 proposed in this invention can be used to evaluate the homogenization level of a given fluid product at the outlet 100b of the dispersion unit 100, such as... Figure 3 As shown. This assessment is a relative measurement, which will be explained later.

[0298] First, the given fluid product that has been homogenized (referred to as the “reference fluid product” in this paper) has characteristics within a temperature range.

[0299] Specifically, method 200 is used to measure the velocity of sound of a reference fluid product at different temperatures in order to obtain a function curve of the velocity of sound as a function of temperature.

[0300] Figure 8 An example of this curve (also known as a "trend curve") is shown in the figure.

[0301] Once the trend curve of a reference fluid product is obtained, method 200 can be used to determine whether the same type of fluid product has actually undergone proper homogenization.

[0302] Specifically, device 1 is placed downstream of homogenization device 100. Device 1 is used to measure the velocity of sound of the fluid product flowing out of homogenization device 100 in real time and compare it with a trend curve.

[0303] When the velocity of sound measured at the measurement temperature exceeds the predetermined acceptable range of the velocity of sound obtained from the trend curve of the temperature, it means that the fluid product needs further homogenization.

[0304] Device 1 can generate an alarm signal to notify of non-compliance.

[0305] When the velocity of sound measured at the measurement temperature is within the predetermined acceptable range of the velocity of sound obtained from the trend curve of the temperature, it means that the fluid product has been properly homogenized.

[0306] refer to Figure 8 The blue curve represents the trend curve of a homogenized reference fluid product (especially based on a coffee cream formula).

[0307] The orange curve represents the velocity of sound of the unhomogenized fluid product (coffee cream) at different temperatures.

[0308] The comparison between the orange and blue curves shows that the coffee cream still needs to be homogenized.

[0309] Using the same device 1, relative measurements of homogenization levels can be performed for different fluid products (previous characteristics), thereby enabling real-time monitoring of the homogenized fluid products flowing out of the homogenization device 100.

[0310] In another application, device 1 includes a pipe 2 filled with a fluid product under static conditions, and device 1 is used to measure the velocity of sound of the fluid product in batches.

[0311] The features and advantages of the method and apparatus for measuring the velocity of sound in a fluid product within a pipeline according to the present invention are apparent from the above description.

[0312] The presence of multiple ultrasonic signal transmission and reception points allows for multiple measurements of sound velocity along the pipe. Multiple measurements are more reliable than single-point measurements.

[0313] Furthermore, the redundancy of ultrasonic transducers is advantageous in the event of damage or failure of one or more transducers. In fact, the failure of one transducer does not jeopardize the overall measurement, which is actually based on the average of the sound velocity values ​​obtained along the pipe.

[0314] Furthermore, placing the ultrasonic transducer on the outer surface of the inner tube avoids direct contact with the fluid flowing within the internal cavity. This facilitates hygienic piping design. Additionally, the ultrasonic transducer is less prone to wear because it does not come into contact with the fluid.

[0315] The method proposed in this invention offers high accuracy in measuring the time of flight in various fluid products, despite the attenuation and / or transparency of the ultrasonic signal in these products. A specific function has been developed to enhance the gain of the received signal, thereby enabling signal detection.

[0316] There is no need to use different types of sensors for specific fluids. The same set of ultrasonic transducers can be used to acquire characteristic signals of various fluid products.

[0317] As is well known, each fluid product has specific characteristics and different quality standards. The solution proposed in this invention allows any fluid product to be characterized by sound velocity using the same equipment.

[0318] Characterization is also the starting point for real-time monitoring of homogenization levels.

[0319] Furthermore, the present invention allows for high-precision measurement of the distance between the transmitter and the receiver / reflector by using an ultrasonic transducer installed in a pipe in which fluid is contained or flowing, to measure ultrasonic dimensions.

[0320] Ultrasonic dimensional measurement is more accurate, faster, and cheaper than mechanical or optical measurement.

[0321] Furthermore, no specialized measuring equipment is required to perform high-precision measurements of pipe dimensions.

Claims

1. A method (200) for measuring the velocity of sound in a fluid product contained within a pipe (2), the method (200) comprising a main cycle, the main cycle sequentially comprising at least one of the following steps performed at least once: - A plurality of ultrasonic signals (201) are emitted toward the fluid product, such that the ultrasonic signals pass through the fluid product, the ultrasonic signals being emitted by a plurality of emission points (21) arranged along the pipe (2); – After the plurality of ultrasonic signals (202) pass through the fluid product, the plurality of ultrasonic signals (202) are received by a plurality of receiving points (22) arranged along the pipe (2), the number of receiving points (22) being the same as the number of transmitting points (21); – Select the group of ultrasonic signals (203) received at the receiving point (22); – For each selected ultrasonic signal in the group of ultrasonic signals, the flight time (207) from the corresponding transmitting point (21) to the corresponding receiving point (22) is measured. – For each selected ultrasonic signal in the group of ultrasonic signals, calculate the speed of sound (208), which is the ratio between the propagation distance of the ultrasonic signal from the corresponding transmission point (21) to the corresponding reception point (22) and the measured flight time. At the end of the main loop, the method (200) further includes the step of calculating an average sound speed (209), the average sound speed (209) being the average of at least a portion of the sound speed values ​​calculated in the main loop.

2. The method (200) according to claim 1, wherein the average sound speed is the arithmetic mean of some or all of the sound speed values ​​calculated in the main loop.

3. The method (200) according to claim 1 or 2, wherein the ultrasonic signal is synchronously emitted by the plurality of emission points (21).

4. The method (200) according to any one of the preceding claims, wherein the conduit (2) is arranged downstream of the high-pressure homogenizer (100) such that the method (200) is performed on the fluid product from the high-pressure homogenizer (100).

5. The method (200) according to any one of the preceding claims, wherein the main loop further includes the step (250) of amplifying the ultrasonic signal after receiving the ultrasonic signal at the receiving point (22).

6. The method (200) of claim 5, wherein the step (250) of amplifying the ultrasonic signal includes increasing the gain of the ultrasonic signal over time.

7. The method (200) according to claim 6, further comprising the step of measuring the amplitude of each ultrasonic signal after each ultrasonic signal is emitted from the corresponding emission point (21), and performing an amplification step (250) in response to the measured amplitude being lower than a minimum value.

8. The method (200) according to any one of the preceding claims, wherein the step of selecting the group of ultrasonic signals (203) includes detecting any fault in the ultrasonic signals received at the receiving point (22), and selecting the corresponding ultrasonic signal in response to the absence of any fault detected.

9. The method (200) according to any one of the preceding claims, wherein the step of selecting the group of ultrasonic signals (203) comprises: – Measure the amplitude (204) of each ultrasonic signal received at the corresponding receiving point (22). -In response to the measured amplitude being within the predetermined acceptable range, the corresponding ultrasonic signal (205) is selected. – In response to the measured amplitude exceeding the predetermined acceptable range, the corresponding ultrasonic signal is rejected (206).

10. The method (200) according to any one of the preceding claims, wherein the emission points (21) are distributed along one side of the pipe (2) and the receiving points (22) are distributed along the opposite side of the pipe (2) relative to the fluid product, wherein a transmitter is arranged at each emission point (21) and the transmitter consists of an ultrasonic sensor (4) configured to emit ultrasonic signals, and a receiver is arranged at each receiving point (22) and the receiver consists of an ultrasonic sensor (14) configured to receive ultrasonic signals.

11. The method (200) according to claim 10, wherein the propagation distance of each ultrasonic signal from the corresponding transmitting point (21) to the corresponding receiving point (22) is the distance between the transmitter that transmits the ultrasonic signal and the corresponding receiver that receives the ultrasonic signal.

12. The method (200) according to any one of claims 1 to 9, wherein each transmitting point (21) coincides with one of the plurality of receiving points (22) to generate a transceiver point, the transceiver points being distributed along the same side of the pipe (2), and at each transceiver point being arranged an ultrasonic transducer (4) configured to transmit and receive ultrasonic signals, the ultrasonic signals transmitted by the ultrasonic transducer (4) being reflected back by a reflecting device (5a) arranged on the opposite side of the pipe (2) relative to the fluid product.

13. The method (200) according to claim 12, wherein the propagation distance of each ultrasonic signal from the corresponding transmitting point (21) to the corresponding receiving point (22) is twice the distance between the ultrasonic transducer (4) and the reflecting device (5a).

14. The method (200) according to claim 12 or 13, further comprising a dimensional measurement procedure (210) executed before the start of the main cycle of the method (200), the dimensional measurement procedure (210) comprising calculating the thickness of the pipe (2) and calculating the propagation distance of the ultrasonic signal from the corresponding transmitting point (21) to the corresponding receiving point (22).

15. The method (200) according to claim 14, wherein calculating the thickness of the pipe (2) comprises at least the following steps: – Measure the velocity of sound at different temperatures in a predetermined sample (211) made of the same material as the pipe (2); – The flight time (212) within the pipe (2) is measured in an empty state, which indicates that there is no fluid within the pipe (2); – Detect the temperature of the pipe (2) (213); – The thickness (214) of the pipe (2) is calculated by multiplying the speed of sound measured at the detected temperature with the time of flight measured inside the pipe (2).

16. The method (200) according to claim 14 or 15, wherein calculating the propagation distance of the ultrasonic signal from the corresponding transmitting point (21) to the corresponding receiving point (22) includes an initial loop, the initial loop sequentially including the following steps performed at least once: – A plurality of ultrasonic signals (216) are emitted toward a selected fluid product contained within the pipe (2), such that the ultrasonic signals pass through the selected fluid product, the ultrasonic signals being emitted from the plurality of emission points (21). – After the plurality of ultrasonic signals (217) pass through the selected fluid product, the plurality of ultrasonic signals (217) are received by the plurality of receiving points (22); – Detect any fault (218) in the ultrasonic signal received at the receiving point (22); For each of the plurality of ultrasonic signals, in response to the absence of any fault detected, the flight time (219) from the corresponding transmitting point (21) to the corresponding receiving point (22) is measured. – For each of the plurality of ultrasonic signals, in response to the absence of any fault detected, the propagation distance (220) of the ultrasonic signal from the corresponding transmitting point (21) to the corresponding receiving point (22) is calculated, the propagation distance (220) being the sum of the thickness of the pipe (2) and the inner diameter of the pipe (2); At the end of the initial cycle, the size measurement procedure (210) further includes a step (221) of calculating an average distance, which is the average of at least a portion of the distances calculated in the initial cycle.

17. The method (200) according to any one of claims 14 to 16, wherein calculating the propagation distance of the ultrasonic signal from the corresponding transmitting point (21) to the corresponding receiving point (22) further comprises the step (215) of measuring the sound velocity of the selected fluid product at different temperatures, the step (215) being performed before the initial cycle.

18. The method (200) according to claim 16 or 17, wherein the average distance is the arithmetic mean of some or all distances calculated in the initial cycle.

19. An apparatus (1) for measuring the velocity of sound in a fluid product according to the method (200) of any one of the preceding claims, said apparatus (1) comprising: – Pipe (2), having an internal cavity (3) for the passage of the fluid product, the internal cavity (3) having a variable diameter spanning the length of the pipe (2); - Multiple ultrasonic transmitters (14) are mounted on the plate of the pipe (2) and configured to emit ultrasonic signals. - Multiple ultrasonic receivers (4) are mounted on the plate of the pipe (2) and located outside the internal cavity (3). The ultrasonic receivers (4) are distributed along the length of the pipe (2) and configured to detect the ultrasonic signal. The number of ultrasonic receivers (4) is the same as the number of ultrasonic transmitters (14). –Control unit (10), configured as follows: The ultrasonic transmitter (14) is commanded to emit multiple ultrasonic signals toward the fluid product, such that the ultrasonic signals pass through the fluid product; The ultrasonic receiver (4) is instructed to receive the multiple ultrasonic signals emitted by the ultrasonic transmitter (14) after the multiple ultrasonic signals have passed through the fluid product; Select the group of ultrasonic signals received by the ultrasonic receiver (4); For each selected ultrasonic signal in the group of ultrasonic signals, the flight time from the corresponding ultrasonic transmitter (14) to the corresponding ultrasonic receiver (4) is measured. For each selected ultrasonic signal in the group of ultrasonic signals, a sound velocity value is calculated, the sound velocity value being the ratio between the propagation distance of the ultrasonic signal from the corresponding ultrasonic transmitter (14) to the corresponding ultrasonic receiver (4) and the measured flight time. Calculate the average sound speed, which is the average of at least a portion of the calculated sound speed values.

20. The device (1) according to claim 19, wherein the control unit (10) is further configured to amplify the ultrasonic signal after the ultrasonic receiver (4) receives the ultrasonic signal.

21. The device (1) according to claim 19 or 20, wherein the conduit (2) comprises: –Outer tube (6); – Inner tube (5), coaxially arranged inside the outer tube (6), the inner tube (5) having an inner surface (5a) defining the inner cavity (3); - Multiple housings (7) are located in the outer surface (5b) of the inner tube (5), and each ultrasonic receiver in the ultrasonic receiver (4) is arranged in one of the housings (7).

Images