Bubble-proof ultrasonic liquid densimeter

Abstract

The application discloses an anti-bubble ultrasonic liquid density meter and relates to the technical field of liquid density detection. The anti-bubble ultrasonic liquid density meter is used to solve the problems of the existing ultrasonic density meter, such as bubble interference in the measurement of a bubble-containing liquid and a complex anti-bubble structure requiring additional power. The anti-bubble ultrasonic liquid density meter comprises a columnar density meter body, a measuring chamber coaxially arranged in the density meter body, a transmitting transducer assembly and a receiving transducer assembly symmetrically arranged on both sides of the lower part of the measuring chamber, and an ultrasonic beam passing through the lower part of the measuring chamber in a radial direction. An upper exchange channel is arranged on the top of the measuring chamber and connected with the outside, and a lower exchange channel is arranged on the bottom edge of the measuring chamber and connected with the outside. The lower end of the lower exchange channel connected with the outside is higher than the upper end of the lower exchange channel connected with the measuring chamber, so that a step barrier is formed. The upper and lower exchange channels constitute a labyrinth convection structure, gas-liquid separation and bubble blocking are realized, the sound beam propagation area is ensured to be pure liquid, the density detection precision is improved, no additional power is required, and the structure is compact and reliable.

Description

Technical Field

[0001] This invention relates to the field of liquid density detection technology, and in particular to an anti-bubble ultrasonic liquid density meter. Background Technology

[0002] Ultrasonic liquid density meters calculate density by measuring the propagation speed of ultrasonic waves in the test medium. The specific working principle is as follows: an ultrasonic transducer emits ultrasonic waves, which are received by a receiving transducer after passing through a fixed length of the test medium. The sound velocity is calculated based on the known propagation length and the measured propagation time, and then the medium density is obtained using a pre-calibrated sound velocity-density characteristic curve. This type of density meter has the advantages of small size and high measurement accuracy; the sound beam diameter can be as low as Φ4mm, and the sound propagation path can be shortened to 10mm. With a dedicated time measurement chip with an accuracy of 50ps, the measurement accuracy of water sound velocity can reach 0.00075%. Furthermore, the effect of temperature on sound velocity is regular and can be compensated for through temperature measurement, further improving the detection accuracy.

[0003] However, in actual industrial scenarios, the liquid being tested often contains air bubbles. The presence of air bubbles significantly alters the propagation speed of ultrasound, causing the measured sound velocity value to deviate from the true value of the pure liquid. This directly leads to a large deviation in the density measurement results, becoming the core bottleneck limiting the measurement accuracy of ultrasonic density meters.

[0004] In existing technologies, most ultrasonic density meters lack reliable bubble isolation structures, and the ultrasonic wave propagation path is directly exposed to a liquid environment containing bubbles, making it impossible to guarantee that the sound beam propagation area is a pure liquid state. Furthermore, some solutions with bubble-proof functions have the following drawbacks: First, incomplete gas-liquid separation allows tiny bubbles to still enter the sound beam propagation area, making it difficult to completely eliminate the interference of bubbles on sound velocity measurement. Second, the anti-bubble structure is complex, often requiring additional power components or precision filter elements, increasing equipment size, manufacturing costs, and failure risks, and failing to achieve the design goals of passive, compact, and maintenance-free operation. Third, the medium exchange response is slow; when the external liquid bubble content changes, the gas-liquid distribution inside the measurement chamber cannot quickly adapt and adjust, easily leading to measurement lag or failure. Fourth, it has poor adaptability to media with different acoustic impedances and low acoustic coupling efficiency, limiting the scope of applicable liquid scenarios.

[0005] The aforementioned problems make it difficult for existing bubble-proof ultrasonic densitometers to achieve stable and high-precision liquid density detection while maintaining a compact size. Therefore, there is an urgent need to develop a new ultrasonic liquid densitometer to effectively eliminate the interference of air bubbles on sound velocity measurement and improve the accuracy and stability of density detection in bubble-containing liquid environments. Summary of the Invention

[0006] The purpose of this invention is to provide an anti-bubble ultrasonic liquid density meter that can achieve gas-liquid separation and physical blocking of bubbles, ensuring that the sound beam propagation area is a pure liquid state, thereby effectively eliminating the interference of bubbles on sound velocity measurement, improving the density detection accuracy and stability in bubble-containing liquid environments, and at the same time, the overall structure is columnar, compact and simple, requires no additional power, and is reliable in operation.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is: an anti-bubble ultrasonic liquid density meter, including a density meter body in the shape of a column, a measuring chamber coaxially provided in the density meter body, a transmitting transducer component and a receiving transducer component symmetrically installed on the density meter body on both sides of the lower part of the measuring chamber, and the ultrasonic beam propagation path between the transmitting transducer component and the receiving transducer component passes through the lower region of the measuring chamber radially. The top of the measuring chamber is provided with an upper exchange channel along its radial direction for connecting the measuring chamber with the outside of the densitometer body, and the bottom edge of the measuring chamber is provided with a lower exchange channel for connecting the measuring chamber with the outside of the densitometer body, and the lower edge of the end of the lower exchange channel that connects with the outside of the densitometer body is higher than the upper edge of the end of the lower exchange channel that connects with the measuring chamber.

[0008] As a further improvement of the present invention, the outer wall of the densitometer body is provided with a mounting groove for mounting a transmitting transducer component and a receiving transducer component, and both the transmitting transducer component and the receiving transducer component include a piezoelectric sheet attached to the bottom surface of the mounting groove.

[0009] As a further improvement of the present invention, the groove opening of the mounting groove is provided with a sealing cover, and a sealing ring is provided between the sealing cover and the side wall of the mounting groove.

[0010] As a further improvement of the present invention, the upper sealing cover of the densitometer body is provided with an upper cover with an opening facing downward, and an adapter plate is provided inside the upper cover. The adapter plate is electrically connected to the piezoelectric sheet through a wire passage and lead wire provided inside the densitometer body. The upper cover is also provided with a cable that is electrically connected to the adapter plate.

[0011] As a further improvement of the present invention, the bottom surface of the mounting groove is provided with a port for connecting to the measuring chamber, and a sound guide plate is provided on the sealing cover of the port, and the piezoelectric plate is attached to the side of the sound guide plate away from the measuring chamber.

[0012] As a further improvement of the present invention, the lower exchange channel is disposed on the side wall of the measurement chamber between the transmitting transducer assembly and the receiving transducer assembly.

[0013] As a further improvement of the present invention, there are two lower exchange channels, and the two lower exchange channels are arranged opposite each other on both sides of the measuring chamber.

[0014] As a further improvement of the present invention, one end of the lower exchange channel that communicates with the measuring chamber is connected to a groove provided at the bottom edge of the measuring chamber.

[0015] As a further improvement of the present invention, the upper exchange channel is a long and narrow flow channel that runs radially through the entire densitometer body along the measuring chamber.

[0016] As a further improvement of the present invention, the cross-sectional area of ​​the upper switching channel is smaller than that of the lower switching channel.

[0017] Beneficial effects Compared with the prior art, the advantages of the anti-bubble ultrasonic liquid density meter of the present invention are as follows: 1. The narrow flow channel design of the upper exchange channel reduces the medium flow rate, allowing the bubbles to rise and separate naturally. At the same time, the lower exchange channel adopts a staggered step structure to form a physical barrier, preventing bubbles from entering the measurement chamber from the bottom. This double protection ensures that the sound beam propagation area is always in a pure liquid state, completely eliminating the interference of bubbles on the sound velocity measurement. Combined with conventional temperature compensation, extremely high liquid density detection accuracy can be achieved. 2. It relies entirely on measuring the density difference between indoor and outdoor environments to drive medium convection and exchange, requiring no additional power components. The overall structure is column-shaped, simple and compact, with stable operation and no wear, making it suitable for confined installation scenarios and with low maintenance costs. 3. When the content of external liquid bubbles changes, the gas-liquid distribution inside the measuring chamber can be automatically adjusted according to the static pressure balance. When the bubble content increases, an upper gas zone and a lower pure liquid measuring zone are automatically formed. When the bubble content decreases, the gas is automatically discharged to restore the full liquid state. The response is timely and avoids measurement lag. 4. By adding subordinate structures such as sound guide plates, the acoustic coupling efficiency of media with different acoustic impedances can be effectively improved, the sound energy reflection loss can be reduced, and the applicable range of liquid scenarios can be broadened.

[0018] The invention will become clearer from the following description, taken in conjunction with the accompanying drawings, which are used to explain embodiments of the invention. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the internal structure of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the internal structure of Embodiment 2 of the present invention; Figure 3 This is a schematic diagram showing the coordination of the upper exchange channel, the measuring chamber, and the lower exchange channel of the present invention.

[0021] The components are: 1-top cover; 2-cable; 3-interchange plate; 4-lead wire; 5-upper exchange channel; 6-sealing cover; 7-piezoelectric element; 8-lower exchange channel; 9-sealing ring; 10-densitometer body; 11-sound guide plate; 12-measuring chamber. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; of course, they can also refer to a mechanical connection or an electrical connection; furthermore, they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] Embodiments of the present invention will now be described with reference to the accompanying drawings.

[0025] Example 1 Specific embodiments of the present invention are as follows: Figure 1 , Figure 3 As shown, an anti-bubble ultrasonic liquid density meter includes a columnar density meter body 10. The density meter body 10 is made of corrosion-resistant insulating material. A measuring chamber 12 is coaxially arranged inside the density meter body 10. The measuring chamber 12 is a cavity extending along the axial direction of the density meter body 10 and is used to contain the liquid to be measured. A transmitting transducer assembly and a receiving transducer assembly are symmetrically mounted on the density meter body 10 on both sides of the lower part of the measuring chamber 12. The ultrasonic beam propagation path between the transmitting transducer assembly and the receiving transducer assembly passes radially through the lower region of the measuring chamber 12.

[0026] Specifically, the outer wall of the densitometer body 10 is provided with mounting slots for installing the transmitting transducer assembly and the receiving transducer assembly. These mounting slots are symmetrically located on the outer walls of the densitometer body 10 on both sides of the lower part of the measuring chamber 12. Both the transmitting and receiving transducers include piezoelectric plates 7 attached to the bottom surface of the mounting slot. The piezoelectric plate 7 located on one side of the measuring chamber 12 serves as the transmitting transducer, and the piezoelectric plate 7 located on the opposite side serves as the receiving transducer. The center line connecting the two piezoelectric plates 7 traverses the lower region of the measuring chamber 12 radially, forming an ultrasonic wave propagation path. The piezoelectric plates 7 are fixed to the bottom surface of the mounting slot by adhesive bonding. The bottom surface of the mounting slot serves as the medium interface for sound wave transmission. The ultrasonic waves generated by the excitation of the piezoelectric plates 7 enter the liquid to be measured in the measuring chamber 12 through the bottom surface of the mounting slot, and after passing through the liquid, are transmitted to the receiving piezoelectric plate 7 from the bottom surface of the opposite mounting slot.

[0027] Furthermore, the mounting groove opening is covered with a sealing cap 6, and a sealing ring 9 is provided between the sealing cap 6 and the side wall of the mounting groove. The sealing cap 6 is fastened to the densitometer body 10 by threads, and the sealing ring 9 is squeezed between the sealing cap 6 and the side wall of the mounting groove to achieve a static seal and prevent external liquid from seeping into the mounting groove and damaging the piezoelectric device.

[0028] The upper end of the densitometer body 10 has a sealing cover 1 with an opening facing downwards. Similarly, a sealing ring 9 is provided between the densitometer body 10 and the upper cover 1. The upper cover 1 is fastened to the top of the densitometer body 10, and an adapter plate 3 is provided inside the upper cover 1. The adapter plate 3 is electrically connected to the piezoelectric element 7 through a wire passage and lead wire 4 provided inside the densitometer body 10. Specifically, a lead wire through hole is opened inside the densitometer body 10 as a wire passage, and the lead wire 4 of the piezoelectric element 7 passes through the wire passage and is soldered upwards to the adapter plate 3. The upper cover 1 is also provided with a cable 2 electrically connected to the adapter plate 3. The cable 2 is used to connect to an external conversion circuit board to realize the transmission and processing of ultrasonic signals. The upper cover 1 completely covers the adapter plate 3 and the lead wire 4 structure to achieve top protection.

[0029] like Figure 1 and Figure 3 As shown, the top of the measuring chamber 12 has an upper exchange channel 5 arranged radially to connect the measuring chamber 12 with the outside of the densitometer body 10. The upper exchange channel 5 is a narrow flow channel that runs radially through the entire densitometer body 10 along the measuring chamber 12. Its flow cross-sectional area is small, which can significantly reduce the flow velocity of the medium. The bottom edge of the measuring chamber 12 has a lower exchange channel 8 arranged to connect the measuring chamber 12 with the outside of the densitometer body 10. The lower edge of the end of the lower exchange channel 8 that connects with the outside of the densitometer body 10 is higher than the upper edge of the end of the lower exchange channel 8 that connects with the measuring chamber 12, that is, the lower exchange channel 8 forms a staggered step structure. The flow cross-sectional area of ​​the upper exchange channel 5 is smaller than the flow cross-sectional area of ​​the lower exchange channel 8.

[0030] Furthermore, the lower exchange channel 8 is disposed on the side wall of the measurement chamber 12 between the transmitting transducer and the receiving transducer. That is, the lower exchange channel 8 is located below the vertical section of the ultrasonic wave propagation path and does not overlap with the ultrasonic wave propagation path in the horizontal projection, thus avoiding disturbance to the sound beam propagation area caused by the opening structure of the lower exchange channel 8. In this embodiment, there are two lower exchange channels 8, which are disposed opposite each other on both sides of the measurement chamber 12. One end of the lower exchange channel 8 that connects to the measurement chamber 12 communicates with a groove located at the bottom edge of the measurement chamber 12. The groove forms a transition space, facilitating smooth flow of the medium between the lower exchange channel 8 and the measurement chamber 12.

[0031] It should be noted that in this embodiment, the bottom surface of the mounting groove is the outer surface of the side wall of the measuring chamber 12, and the piezoelectric sheet 7 is directly attached to this outer surface of the side wall. This structure is suitable for situations where the material of the densitometer body 10 matches the acoustic impedance of the medium to be measured. In this case, acoustic energy can be efficiently transmitted from the piezoelectric sheet 7 through the densitometer body 10 to the liquid to be measured without the need for additional acoustic impedance transition elements.

[0032] The media exchange process when there are no air bubbles in the test medium is as follows: like Figure 3 As shown, when there is a density difference between the liquid inside the measuring chamber 12 and the liquid outside the hydrometer body 10, a static pressure difference is generated between the inner and outer interfaces of the lower exchange channel 8. Let the density of the external liquid be ρ1, the density of the liquid inside the measuring chamber 12 be ρ2, the liquid level outside the hydrometer body 10 and the liquid level inside the measuring chamber 12 be at the same height, and the height of the liquid column measured from the horizontal plane where the lower exchange channel 8 is located be h. Then the difference between the external static pressure and the internal static pressure at the lower exchange channel 8 is (ρ1-ρ2)×g×h, where g is the acceleration due to gravity.

[0033] When ρ1 > ρ2, the external liquid density is higher, and the external static pressure is higher than the internal static pressure. The external liquid flows into the measuring chamber 12 from the lower exchange channel 8, while the liquid inside the measuring chamber 12 flows out from the upper exchange channel 5. When ρ2 > ρ1, the liquid density inside the measuring chamber 12 is higher, and the internal static pressure is higher than the external static pressure. The internal liquid flows out from the lower exchange channel 8, while the external liquid flows in from the upper exchange channel 5. Through this convective exchange, the densities of the media inside and outside the measuring chamber 12 gradually become equal until the convection stops. This exchange process is entirely driven by the density difference, requiring no additional power components, thus achieving passive media renewal.

[0034] The specific procedures for preventing air bubbles in the test medium are as follows: When the external liquid contains air bubbles, the overall density ρ1 of the external gas-liquid mixture is less than the density ρ2 of the pure liquid in the measuring chamber 12, thereby triggering convection—the pure liquid in the measuring chamber 12 flows out from the lower exchange channel 8, and the external liquid containing air bubbles flows into the measuring chamber 12 from the upper exchange channel 5.

[0035] Because the upper exchange channel 5 is a narrow flow channel with a smaller cross-sectional area than the lower exchange channel 8, the flow velocity of the liquid decreases significantly and the residence time is prolonged when it flows through the upper exchange channel 5. During the slow flow process, the air bubbles entrained in the external liquid, due to their significantly lower density than the liquid, naturally rise under the action of buoyancy and separate from the liquid. After entering the measuring chamber 12, the air bubbles continue to rise and accumulate in the upper part of the measuring chamber 12, while the pure liquid sinks to the lower part of the measuring chamber 12. As a result, an upper gas-rich area and a lower pure liquid area are formed inside the measuring chamber 12. The ultrasonic wave propagation path is located in the lower region of the measuring chamber 12, completely within the pure liquid area. The sound velocity measurement is not affected by the air bubbles, and the calculated density value is the true density of the pure liquid.

[0036] Meanwhile, the staggered step structure of the lower exchange channel 8 forms a physical barrier—the lower edge of the end of the lower exchange channel 8 that connects to the outside of the densitometer body 10 is higher than the upper edge of the end of the lower exchange channel 8 that connects to the measuring chamber 12. Bubbles in the external liquid tend to move upwards, but if a bubble wants to enter the measuring chamber 12 through the lower exchange channel 8, it must descend over this step structure. This contradicts the natural upward trend of bubbles, thus preventing bubbles from entering the measuring chamber 12 from the lower channel, eliminating the possibility of bubbles intruding through the lower exchange channel 8 at the source.

[0037] The gas-liquid separation function of the upper exchange channel 5 and the physical blocking function of the lower exchange channel 8 work together to form a double anti-bubble structure, ensuring that the ultrasonic wave propagation area is always in a pure liquid state, effectively eliminating the interference of bubbles on sound velocity measurement.

[0038] The dynamic adaptive adjustment process of this device is detailed below: When the content of external liquid bubbles increases, the density ρ1 of the external mixed medium decreases, convection intensifies, and the bubble-containing liquid continuously enters the measuring chamber 12 from the upper exchange channel 5. Bubbles continuously accumulate in the upper part of the measuring chamber 12, expanding the upper gas zone and correspondingly contracting the lower pure liquid zone. When dynamic equilibrium is reached, the internal and external static pressures at the lower exchange channel 8 are equal, satisfying the following relationship: ρ1×g×h=ρ2×g×h1; Where h is the total liquid column height, h1 is the height of the pure liquid region, and g is the acceleration due to gravity. Since g is the same on both sides of the equation, it can be cancelled out. Therefore, the equilibrium condition simplifies to: ρ1h = ρ2h1; As can be seen from this relationship, as the content of external bubbles increases and ρ1 decreases, the height h1 of the pure liquid region automatically decreases accordingly, but the pure liquid region always maintains a certain height to cover the ultrasonic wave propagation path, ensuring effective measurement.

[0039] As the content of external liquid bubbles gradually decreases, the density ρ1 of the external mixed medium rises, and the external static pressure becomes greater than the static pressure inside the measuring chamber 12. External pure liquid flows into the measuring chamber 12 from the lower exchange channel 8, while the gas in the upper part of the measuring chamber 12 is gradually discharged from the upper exchange channel 5. The height h1 of the pure liquid zone gradually increases, eventually restoring the full liquid measurement state. The entire adjustment process is completed automatically, with a timely response, requiring no manual intervention and avoiding measurement lag.

[0040] In this device, a sealing ring 9 and a sealing cover 6 are sequentially arranged on the outer side of the piezoelectric element 7. The sealing cover 6 forms a static seal by tightening the sealing ring 9 with threads, effectively preventing external liquid from entering the mounting groove and ensuring the long-term stable operation of the piezoelectric device. The lead wire 4 of the piezoelectric element 7 is connected to the adapter plate 3 through the wire passage inside the densitometer body 10. The adapter plate 3 converts the lead wire 4 into a large-section conductor and leads it out through the cable 2, avoiding the problems of easy breakage and signal attenuation caused by direct external connection of the lead wire 4, and improving the reliability of signal transmission. The top cover 1 is fastened to the top of the densitometer body 10, covering the adapter plate 3 and the lead wire 4 structure, realizing top sealing protection, and giving the overall structure good environmental adaptability.

[0041] Example 2 like Figure 2 As shown, this embodiment adds a sound guide plate 11 to the basic embodiment 1. When the acoustic impedance of the densitometer body 10 material is mismatched with that of the medium to be measured, if the piezoelectric element 7 is directly pasted on the bottom surface of the mounting groove, the sound wave will generate a large reflection loss at the interface between the densitometer body 10 and the liquid to be measured, reducing the acoustic coupling efficiency and affecting the measurement sensitivity. Therefore, a port for connecting to the measuring chamber 12 is provided on the bottom surface of the mounting groove, and a sound guide plate 11 is provided on the sealing cover of the port. The piezoelectric element 7 is pasted on the side of the sound guide plate 11 facing away from the measuring chamber 12. In this embodiment, a sealing ring 9 is also provided between the sound guide plate 11 and the port.

[0042] Specifically, the acoustic guide plate 11 is made of a material that matches the acoustic impedance of the medium under test. Its inner surface is in direct contact with the liquid inside the measuring chamber 12, while its outer surface is used for attaching and fixing the piezoelectric element 7. The ultrasonic waves generated by the excitation of the piezoelectric element 7 are directly transmitted to the liquid under test through the acoustic guide plate 11. The acoustic guide plate 11 acts as an acoustic impedance transition, enabling sound energy to couple more efficiently from the piezoelectric element 7 into the liquid medium, reducing sound wave reflection loss at the interface, and improving acoustic coupling efficiency and measurement sensitivity. The acoustic guide plate 11 is sealed on the opening to ensure the airtightness of the measuring chamber 12 and prevent liquid from leaking into the mounting groove through the opening.

[0043] The remaining structure of this embodiment is the same as that of Embodiment 1, and will not be repeated here. Its working process and anti-bubble principle are also the same as those of Embodiment 1: the narrow flow channel of the upper exchange channel 5 realizes gas-liquid separation, and the staggered step structure of the lower exchange channel 8 realizes physical blocking of bubbles. The double protection ensures that the ultrasonic wave propagation path is in the pure liquid area at the bottom of the measuring chamber 12; the medium exchange relies on the density difference passive drive; when the external bubble content changes, the gas-liquid distribution in the measuring chamber 12 is automatically adjusted according to the static pressure balance.

[0044] It should be noted that the addition of the sound guide plate 11 only improves the acoustic coupling process and does not change the working principle of the medium exchange and anti-bubble functions. Regardless of whether the sound guide plate 11 is installed, the medium exchange path, bubble separation mechanism, and dynamic adaptive adjustment process within the measuring chamber 12 remain the same. The only difference is that Example 1 is suitable for cases where the acoustic impedance of the densitometer body 10 material matches that of the measured medium, in which case no additional acoustic impedance transition element is needed, resulting in a more streamlined structure; Example 2 is suitable for cases where the acoustic impedance of the densitometer body 10 material does not match that of the measured medium, improving the acoustic coupling efficiency by adding the sound guide plate 11 and broadening the applicability of the densitometer to different measured liquids.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An anti-bubble ultrasonic liquid density meter, characterized in that, It includes a column-shaped densitometer body (10), and a measuring chamber (12) is coaxially arranged inside the densitometer body (10). A transmitting transducer and a receiving transducer are symmetrically installed on the densitometer body (10) on both sides of the lower part of the measuring chamber (12). The ultrasonic beam propagation path between the transmitting transducer and the receiving transducer passes through the lower region of the measuring chamber (12) radially. The top of the measuring chamber (12) is provided with an upper exchange channel (5) for connecting the measuring chamber (12) and the outside of the densitometer body (10) along its radial direction. The bottom edge of the measuring chamber (12) is provided with a lower exchange channel (8) for connecting the measuring chamber (12) and the outside of the densitometer body (10). The lower edge of the lower exchange channel (8) connecting to the outside of the densitometer body (10) is higher than the upper edge of the lower exchange channel (8) connecting to the measuring chamber (12).

2. The bubble-proof ultrasonic liquid density meter according to claim 1, characterized in that, The outer wall of the densitometer body (10) is provided with a mounting groove for installing the transmitting transducer component and the receiving transducer component. Both the transmitting transducer component and the receiving transducer component include a piezoelectric sheet (7) attached to the bottom surface of the mounting groove.

3. The anti-bubble ultrasonic liquid density meter according to claim 2, characterized in that, The groove opening of the mounting groove is covered with a sealing cap (6), and a sealing ring (9) is provided between the sealing cap (6) and the side wall of the mounting groove.

4. The anti-bubble ultrasonic liquid density meter according to claim 3, characterized in that, The upper sealing cover of the densitometer body (10) is provided with an upper cover (1) with the opening facing downward, and an adapter plate (3) is provided inside the upper cover (1). The adapter plate (3) is electrically connected to the piezoelectric sheet (7) through a wire passage and lead wire (4) provided inside the densitometer body (10). The upper cover (1) is also provided with a cable (2) electrically connected to the adapter plate (3).

5. The bubble-proof ultrasonic liquid density meter according to any one of claims 2-4, characterized in that, The bottom surface of the mounting groove is provided with an opening for connecting to the measuring chamber (12), and a sound guide plate (11) is provided on the sealing cover of the opening. The piezoelectric plate (7) is attached to the side of the sound guide plate (11) away from the measuring chamber (12).

6. The anti-bubble ultrasonic liquid density meter according to claim 1, characterized in that, The lower exchange channel (8) is located on the side wall of the measurement chamber (12) between the transmitting transducer and the receiving transducer.

7. The bubble-proof ultrasonic liquid density meter according to claim 1 or 6, characterized in that, There are two lower exchange channels (8), and the two lower exchange channels (8) are arranged opposite each other on both sides of the measuring chamber (12).

8. The anti-bubble ultrasonic liquid density meter according to claim 1, characterized in that, One end of the lower exchange channel (8) that is connected to the measuring chamber (12) is connected to a groove located at the bottom edge of the measuring chamber (12).

9. The anti-bubble ultrasonic liquid density meter according to claim 1, characterized in that, The upper exchange channel (5) is a narrow flow channel that runs radially through the entire densitometer body (10) along the measuring chamber (12).

10. The bubble-proof ultrasonic liquid density meter according to claim 1 or 9, characterized in that, The cross-sectional area of ​​the upper exchange channel (5) is smaller than that of the lower exchange channel (8).

Images