阅读说明：本技术 在流体产品的均质装置中使用的双隔膜泵以及用于检测所述泵中的泄漏的方法 (Double diaphragm pump for use in a device for homogenizing a fluid product and method for detecting a leak in said pump ) 是由 A·托内利 L·马基 M·贝纳西 M·福莱扎尼 于 2020-02-06 设计创作，主要内容包括：用于检测容纳在两个隔膜(6、16)内的作业流体(P3)泄漏的方法,这两个隔膜将包含液压流体(P2)的液压部段与包含要在双隔膜泵(1)中均质化的流体产品(P1)的工作部段分开,该方法包括以下步骤：检测代表隔膜(6、16)内所包含的流体特性的物理量(S)；以及确定检测到的物理量(S)是否与指示作业流体(P3)与所述流体产品(P1)混合的第一条件相关联,或者其是否与指示作业流体(P3)与液压流体(P2)混合的第二条件相关联,或者其是否与指示作业流体(P3)与流体产品(P1)和液压流体(P2)两者混合的第三条件相关联。(Method for detecting a leakage of a working fluid (P3) contained within two diaphragms (6, 16) separating a hydraulic section containing a hydraulic fluid (P2) from a working section containing a fluid product (P1) to be homogenized in a double diaphragm pump (1), comprising the steps of: detecting a physical quantity (S) representative of a property of the fluid contained in the diaphragm (6, 16); and determining whether the detected physical quantity (S) is associated with a first condition indicating that the working fluid (P3) is mixed with said fluid product (P1), or whether it is associated with a second condition indicating that the working fluid (P3) is mixed with the hydraulic fluid (P2), or whether it is associated with a third condition indicating that the working fluid (P3) is mixed with both the fluid product (P1) and the hydraulic fluid (P2).)

1. A double diaphragm pump (1) for use in a device for homogenizing a fluid product (P1), comprising:

-a pump body (2);

-a first chamber (3) containing the fluid product (P1) to be homogenized, the first chamber (3) being obtained in the pump body (2);

-a second chamber (4) containing hydraulic fluid (P2), said second chamber (4) being obtained in said pump body (2);

-a first diaphragm (6) and a second diaphragm (16), spaced apart from each other, so as to define an intermediate chamber (5) containing a working fluid (P3), said intermediate chamber (5) being obtained in said pump body (2), said first diaphragm (6) being interposed between said first chamber (3) and said intermediate chamber (5) to separate them, said second diaphragm (16) being interposed between said intermediate chamber (5) and said second chamber (4) to separate them;

-a piston (7) partially housed in the second chamber (4) and slidably mounted therein;

-a device (10) for detecting a leak through at least one of said membranes (6, 16),

characterized in that said device (10) for detecting leaks comprises:

-at least one first sensor (11) configured to detect a physical quantity (S) representative of a characteristic of a fluid present in the intermediate chamber (5);

-a control module (12) configured to determine whether the physical quantity (S) detected by the first sensor (11) is associated with a first condition indicative of the mixing of the working fluid (P3) with the fluid product (P1), or whether the physical quantity (S) detected is associated with a second condition indicative of the mixing of the working fluid (P3) with the hydraulic fluid (P2), or whether the physical quantity (S) detected is associated with a third condition indicative of the mixing of the working fluid (P3) with both the fluid product (P1) and the hydraulic fluid (P2).

2. A double membrane pump (1) according to claim 1, characterized in that the device (10) for detecting a leak further comprises a memory (13), the memory being configured to store a first interval of values (I1) of the physical quantity (S) associated with the first condition, a second interval of values (I2) of the physical quantity (S) associated with the second condition, a third interval of values (I3) of the physical quantity (S) associated with the third condition, the first value interval (I1), the second value interval (I2) and the third value interval (I3) are different and non-overlapping, the control module (12) is configured to determine whether the physical quantity (S) detected by the first sensor (11) falls within the first interval of values (I1) or within the second interval of values (I2) or within the third interval of values (I3).

3. A double membrane pump (1) according to claim 1, characterized in that the apparatus (10) for detecting a leak further comprises a memory (13) configured to store a first threshold value (Th1) of the physical quantity (S) associated with the first condition, a second threshold value (Th2) of the physical quantity (S) associated with the second condition, a third threshold value (Th3) of the physical quantity (S) associated with the third condition, the first threshold value (Th1), the second threshold value (Th2) and the third threshold value (Th3) being different, the control module (12) being configured to determine whether the physical quantity (S) detected by the first sensor (11) is lower than only one, two or all of the threshold values (Th1, Th2, Th 3).

4. According to any one of the preceding claimsThe double diaphragm pump (1) of, wherein the control module (12) is further configured to correlate the physical quantity (S) detected by the first sensor (11) with a reference value (S3) indicative of the process fluid (P3) in a pure state_rif) Making a comparison and the control module being responsive to the reference value (S)_rif) Is configured to generate a warning signal and/or a current signal.

5. A double membrane pump (1) according to claim 4, characterized in that the warning signal is of the acoustic or luminous type.

6. A double membrane pump (1) according to any of the preceding claims, further comprising a measurement chamber (14) located outside the pump body (2), the measurement chamber (14) being in fluid communication with the intermediate chamber (5).

7. A double membrane pump (1) according to claim 6, wherein the first sensor (11) is arranged on a first wall (14a) delimiting the measurement chamber (14).

8. A double membrane pump (1) according to claim 7, wherein the apparatus (10) for detecting a leak further comprises a reflector (17) arranged on a second wall (14b) delimiting the measurement chamber (14) and opposite to the first wall (14a), the at least one sensor (11) being an ultrasonic sensor configured to generate sound waves having a frequency between 20kHz and 100MHz and to receive the sound waves reflected back by the reflector (17), the physical quantity (S) being a characteristic physical quantity of sound waves.

9. Double membrane pump (1) according to claim 6, wherein the first sensor (11) is at least partially immersed in a fluid contained in the measurement chamber (14).

10. A double membrane pump (1) according to claim 9, wherein the apparatus (10) for detecting a leak further comprises a reflector (17) arranged on a wall (14b) delimiting the measurement chamber (14), the at least one sensor (11) being an ultrasonic sensor configured to generate sound waves having a frequency between 20kHz and 100MHz and to receive sound waves reflected back by the reflector (17), the physical quantity (S) being a characteristic physical quantity of sound waves.

11. Double diaphragm pump (1) according to claim 8 or 10, wherein the physical quantity (S) is selected from: a speed of acoustic waves in a fluid contained in the measurement chamber (14), an acoustic impedance of a fluid contained in the measurement chamber (14), a propagation time of an acoustic wave, an attenuation of an acoustic wave in a fluid contained in the measurement chamber (14), a frequency spectrum of a reflected acoustic wave, an amplitude of a reflected wave.

12. Double diaphragm pump (1) according to claim 7, wherein the apparatus (10) for detecting a leak further comprises a second sensor (21) arranged on a second wall (14b) delimiting the measurement chamber (14) and opposite to the first wall (14a), the second sensor (21) being an ultrasonic sensor configured to generate sound waves having a frequency between 20kHz and 100MHz, and the at least one first sensor (11) being an ultrasonic sensor configured to generate sound waves having a frequency between 20kHz and 100MHz, the physical quantity (S) being a characteristic physical quantity of sound waves.

13. A double membrane pump (1) according to claim 9, wherein the apparatus (10) for detecting a leak further comprises a second sensor (21) at least partially immersed in the fluid contained in the measurement chamber (14), the second sensor (21) being an ultrasonic sensor configured to generate sound waves having a frequency between 20kHz and 100MHz, and the at least one first sensor (11) being an ultrasonic sensor configured to generate sound waves having a frequency between 20kHz and 100MHz, the physical quantity (S) being a characteristic physical quantity of sound waves.

14. Double diaphragm pump (1) according to claim 12 or 13, wherein the physical quantity (S) is selected from: a speed of acoustic waves in a fluid contained in the measurement chamber (14), an acoustic impedance of a fluid contained in the measurement chamber (14), a propagation time of an acoustic wave, an attenuation of an acoustic wave in a fluid contained in the measurement chamber (14), a resonance frequency.

15. A double membrane pump (1) according to any of the preceding claims, characterized in that the device (10) for detecting a leak comprises a temperature sensor.

16. Method for detecting a leakage of a working fluid (P3) contained within two diaphragms (6, 16) separating a hydraulic section containing a hydraulic fluid (P2) from a working section containing a fluid product (P1) to be homogenized in a double diaphragm pump (1), said method comprising the steps of:

-detecting a physical quantity (S) representative of a property of a fluid contained within said diaphragm (6, 16);

-determining whether the detected physical quantity (S) is associated with a first condition indicating that the working fluid (P3) is mixed with the fluid product (P1), or whether the detected physical quantity (S) is associated with a second condition indicating that the working fluid (P3) is mixed with the hydraulic fluid (P2), or whether the detected physical quantity (S) is associated with a third condition indicating that the working fluid (P3) is mixed with both the fluid product (P1) and the hydraulic fluid (P2).

17. Method according to claim 16, characterized in that the step of determining whether a detected physical quantity (S) is associated with the first condition or the second condition or the third condition comprises: verifying whether the physical quantity (S) falls within a first interval of values (I1) associated with the first condition, or within a second interval of values (I2) associated with the second condition, or within a third interval of values (I3) associated with the third condition, the first interval of values (I1), the second interval of values (I2) and the third interval of values (I3) being different and non-overlapping.

18. The method according to claim 16 or 17, further comprising the steps of: comparing the detected physical quantity (S) with a reference value (S) indicative of the working fluid (P3) in a clean state_rif) A comparison is made and comprises the steps of: in response to the reference value (S)_rif) Is above a predetermined tolerance (delta) to generate a warning signal and/or a current signal.

19. The method according to any one of claims 16 to 18, further comprising the step of:

-generating a first acoustic wave having a frequency between 20kHz and 100MHz and transmitting said first acoustic wave to said working fluid (P3);

-receiving the first sound wave after it has passed through the process fluid (P3), the physical quantity (S) being a characteristic physical quantity of the first sound wave, so that the step of detecting the physical quantity (S) is performed by measuring the physical quantity (S) in the received first sound wave after it has passed through the process fluid (P3).

20. The method according to claim 19, characterized in that the generation of the first sound wave and the reception of the first sound wave after it has passed through the working fluid (P3) are performed by two different ultrasonic sensors (11, 21).

21. Method according to claim 20, characterized in that said physical quantity (S) is selected from: acoustic wave velocity in the working fluid (P3), acoustic impedance of the working fluid (P3), propagation time of the acoustic wave, attenuation of the acoustic wave in the working fluid (P3), resonant frequency.

22. The method of claim 19, wherein the first acoustic wave is generated by a first ultrasonic sensor (11), reflected back by a reflector (17), and received by the first ultrasonic sensor (11).

23. The method according to claim 22, characterized in that said physical quantity (S) is selected from: acoustic wave velocity in the working fluid (P3), acoustic impedance of the working fluid (P3), propagation time of the acoustic wave, attenuation of the acoustic wave in the working fluid (P3), frequency spectrum of the reflected acoustic wave, amplitude of the reflected signal.

24. The method according to any one of claims 16 to 18, further comprising the step of:

-generating and sending first optical radiation in the infrared or near infrared spectrum to the working fluid (P3);

-receiving the first optical radiation after it has passed through the working fluid (P3), the physical quantity (S) being characteristic physical quantities of the first optical radiation, the step of detecting the physical quantity (S) being performed for these characteristic physical quantities by measuring the physical quantity (S) in the received first optical radiation after it has passed through the working fluid (P3).

Technical Field

The present invention relates to a double diaphragm pump for use in a device for homogenizing a fluid product and to a method for detecting a leak in such a pump.

Background

The invention presented herein is used in the food industry, in particular in the field of dairy products. The invention can also be used in the chemical, pharmaceutical or cosmetic industry.

Even in different currently known embodiments, the homogenizing device comprises a high-pressure pump and a homogenizing valve which act on the fluid product containing the particles in order to:

-crushing the particles to make them uniform in size, reducing the average size and distribution differences, in order to stabilize the product and increase its shelf life in the case of emulsions;

in the case of pharmaceutical applications, breaking the cell membrane to facilitate extraction of the active ingredient;

-modifying the structure of the particles in the case of chemical applications and cellulose;

in this context, attention is focused on pumping systems.

It is known to use diaphragm (or membrane) pumps which employ a flexible member (precisely referred to as "diaphragm" or "membrane") to transmit a pulsating force to the fluid to be homogenized, thus ensuring separation of the fluid itself with respect to the (contaminated) external environment.

For example, document US 2012/0011998 shows a diaphragm pump in which a flexible member acts as a spacer element between a containing chamber of the fluid to be homogenized and a hydraulic chamber containing oil and in which a piston is housed.

The flexible member of US 2012/0011998 is preferably formed by two diaphragms arranged to define an intermediate chamber. The diaphragms are associated with a system for detecting leaks caused by rupture or damage of one of the two diaphragms, the system including a pressure sensor capable of detecting pressure changes associated with the leaks.

The above-described method for detecting leaks does not allow identification of a diaphragm that is actually damaged. As the membrane in contact with the oil is damaged, the system for detecting leaks sends a signal that triggers the machine to stop. In this case, machine stops can be avoided, since the "product side" membrane is still intact and ensures separation from the contaminated area.

Disclosure of Invention

Against this background, the technical task on which the present invention is based consists in providing a double diaphragm pump for use in a device for homogenizing a fluid product and a method for detecting leaks in such a pump, which eliminate the drawbacks of the prior art described above.

In particular, the object of the present invention is to propose a double diaphragm pump for use in a device for homogenizing a fluid product, in which it is possible to detect the damage of one or the other diaphragm and to stop the homogenizing device only when it is really necessary.

Another object of the present invention is to propose a method for detecting leaks in a double diaphragm pump which accurately locates the leak without disassembling the pump.

The technical task mentioned and the aims specified are substantially achieved by a double diaphragm pump for use in an apparatus for the homogenization of a fluid product, comprising:

-a pump body;

-a first containing chamber containing the fluid product to be homogenized, the first chamber being obtained in the pump body;

-a second containing chamber containing a hydraulic fluid, said second containing chamber being obtained in said pump body;

-a first diaphragm and a second diaphragm, spaced apart from each other, so as to define an intermediate chamber containing a working fluid, said intermediate chamber being obtained in the pump body, said first diaphragm being interposed between the first chamber and the intermediate chamber to separate them, said second diaphragm being interposed between the intermediate chamber and the second chamber to separate them;

-a piston partially housed in the second chamber and slidably mounted in the second chamber;

-means for detecting a leak through at least one of said membranes,

characterized in that said device for detecting leaks comprises:

-at least one first sensor configured to detect a physical quantity representative of a property of the fluid present in the intermediate chamber;

-a control module configured to determine whether the physical quantity detected by the first sensor is associated with a first condition indicative of the working fluid being mixed with the fluid product, or whether the detected physical quantity is associated with a second condition indicative of the working fluid being mixed with the hydraulic fluid, or whether the detected physical quantity is associated with a third condition indicative of the working fluid being mixed with both the fluid product and the hydraulic fluid.

According to one embodiment, the apparatus for detecting a leak further comprises a memory configured to store:

-a first interval of values of a physical quantity associated with said first condition;

-a second interval of values of the physical quantity associated with said second condition;

-a third interval of values of the physical quantity (S) associated with said third condition.

The first, second and third value intervals are different and non-overlapping.

In this embodiment, the control module is configured to determine whether the physical quantity detected by the first sensor falls within the first interval of values or within the second interval of values or within the third interval of values.

According to another embodiment, an apparatus for detecting a leak includes a memory configured to store:

-a first threshold value of a physical quantity, said first threshold value being associated with said first condition;

-a second threshold value of said physical quantity, said second threshold value being associated with said second condition;

-a third threshold value of said physical quantity, said third threshold value being associated with said third condition.

The first threshold, the second threshold, and the third threshold are different.

In this embodiment, the control module is configured to determine whether the physical quantity detected by the first sensor is below only one, two or all three of the thresholds.

Preferably, the control module is further configured to compare the physical quantity detected by the first sensor with a reference value indicative of the working fluid in a pure state, and the control module is configured to generate a warning signal and/or a current signal in response to a difference above a predetermined tolerance from the reference value.

For example, the warning signal is of the acoustic and/or luminous type.

Preferably, the double diaphragm pump further comprises a measurement chamber located outside the pump body. The measurement chamber is in fluid communication with the intermediate chamber.

According to one embodiment, the first sensor is arranged on a first wall delimiting the measurement chamber or is at least partially immersed in a fluid contained in the measurement chamber.

In a configuration known as "pulse echo", the device for detecting leaks also comprises a reflector arranged on a second wall (opposite to the first wall) delimiting the measurement chamber.

The first sensor is an ultrasonic sensor configured to generate sound waves having a frequency between 20kHz and 100MHz and to receive sound waves reflected back by the reflector.

Thus, the physical quantity is a characteristic physical quantity of the acoustic wave, for example, selected from the following: a velocity of an acoustic wave in a fluid contained in the measurement chamber, an acoustic impedance of a fluid contained in the measurement chamber, a propagation time of an acoustic wave, an attenuation of an acoustic wave in a fluid contained in the measurement chamber, a frequency spectrum of a reflected acoustic wave, an amplitude of a reflected wave.

In a configuration known as "through-transmission", the device for detecting leaks comprises a second sensor (instead of a reflector) arranged on a second wall (opposite to the first wall) delimiting the measurement chamber or at least partially immersed in the fluid contained in the measurement chamber.

The second sensor is an ultrasonic sensor configured to generate acoustic waves having a frequency comprised between 20kHz and 100 MHz. Thus, the first sensor is an ultrasonic sensor configured to receive these acoustic waves.

Here, too, the physical quantity is a characteristic physical quantity of the acoustic wave, for example, selected from the following: the velocity of the acoustic wave in the fluid contained in the measurement chamber, the acoustic impedance of the fluid contained in the measurement chamber, the propagation time of the acoustic wave, the attenuation of the acoustic wave in the fluid contained in the measurement chamber, the resonance frequency.

Preferably, in all proposed embodiments, the device for detecting a leak comprises a temperature sensor.

The technical task mentioned and the aims specified are substantially achieved by a method for detecting a leakage of a working fluid contained in two diaphragms that separate a hydraulic section containing the hydraulic fluid from a working section containing a fluid product to be homogenized in a double-diaphragm pump, comprising the steps of:

-detecting a physical quantity representative of a property of the fluid contained within the membrane;

-determining whether the detected physical quantity is associated with a first condition indicative of the working fluid being mixed with the fluid product, or whether it is associated with a second condition indicative of the working fluid being mixed with the hydraulic fluid, or whether it is associated with a third condition indicative of the working fluid being mixed with both the fluid product and the hydraulic fluid.

According to one embodiment, the step of determining whether the detected physical quantity is associated with the first condition or the second condition or the third condition comprises: verifying whether the physical quantity falls within a first interval of values associated with the first condition or a second interval of values associated with the second condition or a third interval of values associated with the third condition.

The first, second and third value intervals are different and non-overlapping.

Preferably, the method further comprises the steps of: comparing the detected physical quantity with a reference value indicative of the process fluid in a pure state, and the steps of: generating a warning signal and/or a current signal in response to a difference above a predetermined tolerance from the reference value.

Preferably, the method further comprises the steps of:

-generating a first acoustic wave having a frequency between 20kHz and 100MHz and transmitting the first acoustic wave to the process fluid;

-receiving the first sound wave after the first sound wave has passed through the process fluid, the physical quantity being a physical quantity characteristic of the first sound wave, so that the step of detecting the physical quantity is performed by measuring the physical quantity in the received first sound wave after the first sound wave has passed through the process fluid.

According to one embodiment, the generation of the first sound wave and the reception of the first sound wave after it has passed through the process fluid is performed by two different ultrasonic sensors.

For example, the physical quantities are selected from: acoustic wave velocity in the working fluid, acoustic impedance of the working fluid, propagation time of the acoustic wave, attenuation of the acoustic wave in the working fluid, resonant frequency.

According to another embodiment, the first acoustic wave is generated by a first ultrasonic sensor, reflected back by a reflector, and received by the first ultrasonic sensor.

In this case, the physical quantity is selected from: acoustic wave velocity in the working fluid, acoustic impedance of the working fluid, propagation time of the acoustic wave, attenuation of the acoustic wave in the working fluid, frequency spectrum of the reflected acoustic wave, amplitude of the reflected signal.

According to a further embodiment, the method further comprises the steps of:

-generating first optical radiation in the infrared or near-infrared spectrum and transmitting the first optical radiation to the working fluid;

-receiving the first optical radiation after it has passed through the working fluid.

In this embodiment, the physical quantity is a characteristic physical quantity of the first optical radiation for which the step of detecting the physical quantity is performed by measuring the physical quantity in the received first optical radiation after the first optical radiation has passed through the working fluid.

Drawings

Further features and advantages of the invention will become more apparent from the schematic and therefore non-limiting description of a preferred but non-exclusive embodiment of a device for homogenizing a fluid product and a method for detecting a leak in a pump, as illustrated in the accompanying drawings, in which fig. 1 and 2 schematically show a first and a second embodiment, respectively, of a double diaphragm pump for use in a device for homogenizing a fluid product according to the invention.

Detailed Description

With reference to the figures, numeral 1 indicates a double diaphragm pump, in particular for use in a device for homogenizing a fluid product P1.

The double membrane pump comprises a pump body 2, in which pump body 2 three different chambers are obtained:

a first chamber 3 containing a fluid product P1 to be homogenized;

a second chamber 4 containing hydraulic fluid P2;

an intermediate chamber 5 containing a working fluid P3.

The intermediate chamber 5 is interposed between the first chamber 3 and the second chamber 4 and is separated from the first chamber 3 and from the second chamber 4 by two diaphragms 6, 16. The two diaphragms 6, 16 are spaced apart from each other to define an intermediate chamber 5.

In particular, the first diaphragm 6 separates the intermediate chamber 5 from the first chamber 3, and the second diaphragm 16 separates the intermediate chamber 5 from the second chamber 4.

The piston 7 is partially accommodated in the second chamber 4. The double membrane pump 1 comprises movement means (not shown) operatively acting on the piston 7 to make it slide linearly inside the second chamber 4. In particular, the piston 7 is slidably mounted with respect to the inner wall delimiting the second chamber 4.

The double diaphragm pump 1 further comprises a device 10 for detecting a leak through at least one of the two diaphragms 6, 16. In particular, if one of the two diaphragms 6, 16 is damaged, the working fluid P3 is contaminated by one or both of the fluids present in the adjacent chambers (first chamber 3 and/or second chamber 4).

Advantageously, the device 10 for detecting leaks comprises:

at least one first sensor 11 configured to detect a physical quantity S representative of the characteristics of the fluid present in the intermediate chamber 5;

a control module 12 configured to determine whether the physical quantity S detected by the first sensor 11 is associated with a first condition indicating the mixing of the operative fluid P3 with the fluid product P1, or with a second condition indicating the mixing of the operative fluid P3 with the hydraulic fluid P2, or with a third condition indicating the mixing of the operative fluid P3 with both the fluid product P1 and the hydraulic fluid P2.

The apparatus 10 for detecting leaks further comprises a memory 13 configured to store:

-a first interval of values I1 of the physical quantity S associated with a first condition;

-a second interval of values I2 of the physical quantity S associated with a second condition;

a third interval of values I3 of the physical quantity S associated with a third condition.

The first value interval I1, the second value interval I2 and the third value interval I3 are different and do not overlap.

The control module 12 is configured to determine whether the physical quantity S detected by the first sensor 11 falls within a first value interval I1 or within a second value interval I2 or within a third value interval I3.

Alternatively, the memory 13 is configured to store:

a first threshold Th1 of a physical quantity S associated with a first condition;

a second threshold Th2 of the physical quantity S associated with a second condition;

a third threshold Th3 of the physical quantity S associated with a third condition.

The first threshold Th1, the second threshold Th2, and the third threshold Th3 are different.

In this case, the control module 12 is configured to determine whether the physical quantity S detected by the first sensor 11 is lower than only a single threshold, two thresholds, or three.

Preferably, the apparatus 10 for detecting leaks also comprises a temperature sensor (not shown). For example, the temperature sensor is arranged to detect the temperature of the fluid present in the measurement chamber 14.

Advantageously, the double membrane pump 1 further comprises a measurement chamber 14 external to the pump body 2.

The measurement chamber 14 is in fluid communication with the intermediate chamber 5 for receiving the working fluid P3. For example, the measurement chamber 14 is in fluid communication with the intermediate chamber 5 through a duct 15 obtained in the pump body 2.

Under optimal conditions (intact diaphragm 6, 16, i.e. not damaged), the measurement chamber 14 is filled with a working fluid P3.

Preferably, the first sensor 11 is arranged on a first wall 14a delimiting the measurement chamber 14, as shown in fig. 1 and 2.

The position and inclination of the first sensor 11 on the first wall 14a are selected according to the type of the working fluid P3 and the physical quantity S to be detected.

According to the first embodiment shown in fig. 1, the apparatus 10 for detecting leaks also comprises a reflector 17, which reflector 17 is arranged on a second wall 14b delimiting the measurement chamber 14 and opposite the first wall 14 a.

In this case, the first sensor 11 is an ultrasonic sensor configured to generate an acoustic wave having a frequency between 20kHz and 100MHz and to receive the acoustic wave reflected back by the reflector 17.

In other words, the reflector 17 is located on the opposite side of the first sensor 11 with respect to the fluid filling the measurement chamber 14.

In an alternative embodiment, not shown, the first sensor 11 is at least partially immersed in the fluid contained in the measurement chamber 14. In this case, the first sensor 11 is introduced into the measurement chamber 14 through a through slot or opening obtained in the wall delimiting the measurement chamber 14.

In this context, the term "reflector" refers to any object having reflective properties. For example, a steel plate is to be understood as a reflector.

For example, the second wall 14b may be made of steel, constituting the reflector 17 itself.

Thus, in the first embodiment, the first sensor 11 performs the functions of a transmitter and a receiver of signals (here, acoustic waves) by means of the simple reflector 17. This configuration is known in the art as "pulse echo".

Therefore, the physical quantity S detected by the first sensor 11 is a characteristic physical quantity of the acoustic wave.

For example, in a first embodiment, the physical quantity S is selected from: acoustic wave velocity in the fluid, acoustic impedance of the fluid, propagation time of the acoustic wave, attenuation of the acoustic wave in the fluid, frequency spectrum of the reflected acoustic wave, amplitude of the reflected signal.

The physical quantity S is chosen in relation to the fluids considered, namely the fluid product P1 to be homogenized, the working fluid P3 and the hydraulic fluid P2.

In a variant of the "pulse-echo" configuration, not shown, it is provided to use a plurality of first sensors 11 mounted on the first wall 14a or partially immersed in the fluid contained in the measurement chamber 14, each sensor being configured to detect a different characteristic physical quantity S of the acoustic waves.

Each first sensor 11 may be coupled with a corresponding reflector 17. Alternatively, by making the second wall 14b of steel, the second wall 14b acts as a single reflector 17 for all the first sensors 11.

According to a second embodiment, shown in fig. 2, two sensors are provided: one for transmitting sound waves and the other for receiving sound waves.

Thus, this configuration, known in the art as "through-transmission", provides at least one pair of sensors (emitter-receiver) between which the process fluid P3 is interposed.

The first sensor 11 is an ultrasonic sensor configured to receive acoustic waves having a frequency comprised between 20kHz and 100 MHz. Hereinafter, the first sensor 11 is referred to as a "receiver".

The second ultrasonic sensor 21, hereinafter referred to as "emitter", is alternatively configured to generate acoustic waves having a frequency comprised between 20kHz and 100 MHz.

In fig. 2, the first sensor 11 is arranged on a first wall 14a of the measurement chamber 14, while the second sensor 21 is arranged on a second wall 14b opposite to the first wall 14 a.

In an alternative embodiment, not shown, both the first sensor 11 and the second sensor 12 are at least partially immersed in the fluid contained in the measurement chamber 14. In this case, the first sensor 11 and the second sensor 21 are introduced into the measurement chamber 14 through slots or openings obtained in the wall delimiting the measurement chamber 14.

For example, in a second embodiment, the physical quantity S is selected from: acoustic wave velocity in the fluid, acoustic impedance of the fluid, propagation time of the acoustic wave, attenuation of the acoustic wave in the fluid, resonant frequency.

The distance between the transmitter and the receiver, their position and their mutual inclination are selected according to the characteristics of the operating fluid P3 and the physical quantity S to be detected.

The physical quantity S is chosen in relation to the fluids considered, namely the fluid product P1 to be homogenized, the working fluid P3 and the hydraulic fluid P2.

In a variant of the "through transmission" configuration, not shown, it is provided to use a plurality of first sensors 11 and second sensors 21, respectively mounted on the first wall 14a and on the second wall 14b (or partially immersed in the fluid present in the measurement chamber 14), each sensor being configured to detect/emit a different characteristic physical quantity S of the acoustic wave.

In all of the embodiments described, the control module 12 is configured to set various parameters of the sound waves, such as: emission window, amplification or attenuation of the acoustic wave, time window within which a characteristic physical quantity of the acoustic wave is detected.

Preferably, in both the first and second embodiments, the control module 12 is also configured to compare the physical quantity S detected by the first sensor 11 with a reference value S indicative of the working fluid P3 in a clean state, i.e. not mixed with the fluid product P1 to be homogenized and/or with the hydraulic fluid P2_rifA comparison is made. In response to a reference value S_rifA difference above a predetermined tolerance Δ (by comparison), the control module 12 generates a warning signal of the acoustic and/or luminous type.

Alternatively or additionally, the control module 12 generates a 4-20 mA current signal that can be viewed on a screen (e.g., on a PLC).

Preferably, the control module 12 comprises an electronic module suitably programmed to perform the above-mentioned functions, which may correspond to different hardware and/or conventional software entities belonging to the programmed module.

As an alternative to the ultrasound techniques described above with reference to the various embodiments, optical techniques, such as optical microscopy or NIR techniques (acronym for "Near infrared (Near) Red") may also be used.

In the case of optical microscopy, the first sensor 11 is an optical sensor and the physical quantity detected is an optical signal emitted by a light source. An image of the fluid present in the intermediate chamber 5 is acquired, the analysis of which provides information about the contamination of the working fluid P3 by the product fluid P1 (hence the "first condition"), or by the hydraulic fluid P2 (hence the "second condition"), or by both a portion of the product fluid P1 and a portion of the hydraulic fluid P2 (hence the "third condition").

In the case of NIR techniques, spectrophotometric analysis of the process fluid P3 is performed instead.

NIR spectrophotometers include a light source (e.g., a tungsten-halogen lamp), a monochromator, a sampler, or an interface for presenting a sample, and detectors for measuring reflectance and transmittance (e.g., lead sulfate, silicon, and indium arsenide and gallium arsenide).

The characteristics of the double diaphragm pump used in the device for homogenizing a fluid product according to the invention, as well as the method for detecting a leak in said pump, and the advantages thereof, are clear from the above description.

In particular, the device for detecting leaks in the intermediate chamber allows to distinguish such leaks as being associated with damages/breakages of the "product side" diaphragm or the "piston side" membrane or both.

In fact, by detecting the characteristic characteristics of the working fluid contained between the diaphragms contaminated or by the hydraulic fluid in which the fluid product to be homogenized or the piston, respectively, is immersed, the control module is able to determine whether such damage/breakage involves the first diaphragm (product side) or the second diaphragm (piston side) or both.

In fact, in the first case, the fluid product to be homogenized is mixed with the process fluid, thus contaminating the process fluid and causing a "first condition" detectable by measuring a selected physical quantity.

The homogenizing device can then be stopped, since damage means "product side" contamination.

In the second case, however, the working fluid is contaminated by hydraulic fluid ("second condition"), it may not be necessary to stop the homogenizing device as long as the "product side" is protected from contamination.

In a third situation, contamination of the process fluid occurs both on the "product side" and on the "piston side", so that the homogenizing device is subsequently stopped.

Selecting different and non-overlapping value intervals (or thresholds) of the physical quantities, it is possible to distinguish which membrane is damaged/broken, and it is possible to perform certain action(s) on a homogeneous device employing a double membrane pump.

The proposed solution allows to determine in advance which diaphragm is damaged/broken, avoiding to stop the system and remove parts if not necessary.

Furthermore, the ability to detect different physical quantities allows the proposed method to be used for a variety of fluid products being treated.