Concentric atomizer

Abstract

The concentric atomizer comprises a gas sleeve and a liquid introduction pipe which are coaxially arranged, the gas sleeve comprises a gas channel used for gas circulation, and a sleeve cavity is formed in the gas sleeve; a liquid introduction pipe for circulating a liquid sample is arranged in the sleeve cavity; wherein the gas circulation direction of the gas sleeve is the same as the liquid sample circulation direction of the liquid introduction pipe, and the gas channel surrounds the liquid introduction pipe; the liquid introduction pipe comprises a stable section, the tail section of the liquid introduction pipe forms the stable section, the stable section comprises a first inner cavity used for circulating a liquid sample, and the radial size of the first inner cavity is gradually increased in the circulating direction of the liquid sample, so that the flow speed of the liquid sample is gradually reduced when the liquid sample flows through the stable section, and the liquid sample is shaped and is conveniently and uniformly sheared by gas; and as the radial size of the first inner cavity is gradually increased, the risk of blockage at the tail end outlet which is easy to block is reduced, and wide adaptability is achieved.

Description

Technical Field

[0001] This application relates to the technical field of sample introduction devices for analytical instruments, specifically to a concentric nebulizer. Background Technology

[0002] Pneumatic concentric nebulizers are key components in atomic spectroscopy and mass spectrometry, converting liquid samples into aerosols. Traditional concentric nebulizers (such as the Meinhard type) use a tapered capillary with a sharp tip, utilizing the Venturi effect generated by a high-speed airflow at the nozzle to draw in and break up the liquid, achieving a sample intake efficiency of approximately 1 mL / min. The analysis of trace samples is crucial for applications with limited sample control, such as clinical, biological, and forensic medicine. Furthermore, minimizing waste is essential when analyzing toxic and radioactive samples. Therefore, the extremely small inner diameter of the capillary tip in traditional concentric nebulizers and direct injection nebulizers easily leads to physical blockage of samples containing biological cells, nanoparticle clusters, or high-salt precipitates. For biological cells with a diameter of approximately 10-20 μm, they are easily broken and lost when passing through the narrow tip and undergoing severe shearing, resulting in low technical efficiency in single-cell analysis and causing low and unstable transfer efficiency. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. Therefore, this application proposes a concentric atomizer that is not only less prone to pipe blockage but also stabilizes the flow pattern, forming small and stable aerosols.

[0004] A concentric nebulizer according to an embodiment of this application includes: a gas sleeve including a gas channel for gas flow; a sleeve cavity formed within the gas sleeve; and a liquid inlet tube for flow of a liquid sample, the liquid inlet tube being disposed within the sleeve cavity and coaxially arranged with the gas sleeve; wherein the direction of gas flow in the gas sleeve is the same as the direction of liquid sample flow in the liquid inlet tube, and the gas channel surrounds the liquid inlet tube; the liquid inlet tube includes a stabilizing section, the end of which is formed as the stabilizing section, the stabilizing section including a first inner cavity for flow of a liquid sample, the radial dimension of the first inner cavity gradually increasing along the flow direction of the liquid sample, and gas flowing out from the end of the gas sleeve to perform circumferential shearing on the liquid sample flowing out from the end of the stabilizing section.

[0005] According to an embodiment of this application, a gap is formed between the liquid inlet pipe and the gas sleeve, and the gap forms the gas channel.

[0006] According to an embodiment of this application, the cross-sectional shape of the inner wall of the stable section in the direction of liquid sample flow is one of three: a straight line, a stepped broken line, and a parabola.

[0007] According to an embodiment of this application, the liquid inlet tube includes an inlet section, the inlet section includes a second inner cavity for introducing a liquid sample, the radial dimensions of the second inner cavity are all consistent, the end of the inlet section is connected to the beginning of the stabilizing section, and the radial dimension of the second inner cavity is the same as the radial dimension of the beginning of the first inner cavity.

[0008] According to an embodiment of this application, the radial dimension D1 of the beginning of the first inner cavity is smaller than the radial dimension D2 of the end of the first inner cavity, and the axial length L of the stable segment satisfies L≥5. (D2-D1).

[0009] According to an embodiment of this application, the radial dimension D1 of the beginning of the first inner cavity is between 30 μm and 70 μm, the radial dimension D2 of the end of the first inner cavity is between 60 μm and 150 μm, and the ratio of D2 / D1 between D1 and D2 is between 1.5 and 3.0.

[0010] According to an embodiment of this application, the gas channel has an acceleration section at its end, the acceleration section gradually contracts along the gas flow direction, and the dimension of the end of the acceleration section in the radial direction of the gas sleeve is between 10 μm and 50 μm.

[0011] According to an embodiment of this application, the gas sleeve has a guide member formed at the end of the gas channel. The guide member is inclined toward the direction of the liquid inlet pipe, and the guide member can encapsulate and shear the liquid sample flowing out of the end of the liquid inlet pipe.

[0012] According to an embodiment of this application, the liquid inlet tube and the gas sleeve are integrally formed by precision micromachining or assembled and fixed by a high concentricity fixture; the coaxiality error between the liquid inlet tube and the gas sleeve is less than 5 μm.

[0013] According to embodiments of this application, the liquid inlet tube is made of fused silica, sapphire, or a chemically inert polymer.

[0014] The concentric nebulizer according to the embodiments of this application has at least the following beneficial effects: the stabilization section has an expanding flow channel structure, which allows the liquid sample to gradually decrease in flow velocity and be shaped when flowing through the stabilization section, making it easier to be uniformly sheared by the gas to form a small and stable aerosol, thereby improving the signal-to-noise ratio and reproducibility of the analytical signal; at the same time, it also reduces the risk of clogging and has wide adaptability, suitable for complex matrix analysis that is difficult to be stably handled by traditional nebulizers, such as single particle / single cell ICP-MS, high-salt environment samples, nanoparticle suspensions, and proteomics pretreatment solutions.

[0015] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0016] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0017] Figure 1 This is a schematic diagram of the structure of the concentric atomizer according to an embodiment of this application; Figure 2 for Figure 1 A schematic diagram of the two sections of the liquid inlet tube in the concentric atomizer. Figure 3 for Figure 1 Enlarged schematic diagram of the end section of the concentric atomizer; Figure 4 For liquid samples in Figure 3 A schematic diagram of the shaping process in the stable segment; Figure 5 This is a schematic diagram of another structure for the end section of a concentric atomizer; Figure 6 This is a schematic diagram of another structure at the end of a concentric atomizer.

[0018] Figure label: 100. Gas casing; 110. Gas passage; 111. Acceleration section; 120. Casing cavity; 130. Flow guide; 140. Gas inlet; 200. Liquid inlet pipe; 210. Stabilization section; 211. First inner cavity; 220. Inlet section; 221. Second inner cavity; 300, liquid column. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0020] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0022] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0023] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0024] Pneumatic concentric nebulizers are key components in atomic spectroscopy and mass spectrometry, converting liquid samples into aerosols. Traditional concentric nebulizers (such as the Meinhard type) use a tapered capillary with a sharp tip, utilizing the Venturi effect generated by a high-speed airflow at the nozzle to draw in and break up the liquid, achieving a sample intake efficiency of approximately 1 ml / min. The analysis of trace samples is crucial for applications with limited sample control, such as clinical, biological, and forensic medicine. Furthermore, minimizing waste is essential when analyzing toxic and radioactive samples.

[0025] Therefore, the miniaturization of liquid samples has spurred the development of microflow nebulizers, including existing standard microflow concentric nebulizers, V-groove nebulizers, ultrasonic nebulizers, and direct injection nebulizers.

[0026] Among them, the micro-flow concentric atomizer uses a fused silica tube with a thin inner diameter (usually 70-150μm) and a sharp conical end, wrapped with a concentric gas sleeve, and works by relying on the Venturi effect; the V-groove atomizer has the liquid flowing along an open groove or plate, and high-pressure gas is ejected from a small hole below to shear the liquid surface; the ultrasonic atomizer uses piezoelectric ceramics to generate high-frequency vibrations, forcing the liquid to pass through a microporous mesh to form microdroplets; the direct injection atomizer has a capillary inserted directly into the center of the plasma, without a mist chamber, and a transmission efficiency of nearly 100%.

[0027] However, the capillary tubes of traditional concentric nebulizers and direct injection nebulizers are prone to physical clogging due to their extremely small inner diameter at the tip. For samples containing biological cells, nanoparticle clusters, or high-salt precipitates, the capillaries are particularly susceptible to clogging. Biological cells with a diameter of approximately 10-20 μm are easily broken and lost when passing through the narrow tip and undergoing severe shearing, resulting in low technical efficiency and unstable transmission in single-cell analysis. The microporous mesh of ultrasonic nebulizers is also prone to clogging. While V-groove nebulizers prevent clogging by increasing the pore size, this often comes at the cost of sacrificing nebulization efficiency and aerosol uniformity.

[0028] In view of this, this application proposes a concentric atomizer that is not only less prone to pipe blockage, but also has a stable flow pattern, forming a small and stable aerosol.

[0029] Please see Figure 1 and Figure 2 The concentric atomizer disclosed in this application includes a gas sleeve 100 and a liquid inlet tube 200. A sleeve cavity 120 is formed inside the gas sleeve 100, and the liquid inlet tube 200 is coaxially disposed in the sleeve cavity 120 inside the gas sleeve 100. The gas sleeve 100 includes a gas channel 110 for gas flow, and the liquid inlet tube 200 is made of fused silica, sapphire, or a chemically inert polymer and is used to introduce the liquid sample to be atomized.

[0030] like Figure 1 As shown, the arrows inside the gas channel 110 and the liquid inlet pipe 200 indicate the directions of gas flow and liquid sample flow, respectively. The direction in which the liquid inlet pipe 200 guides the liquid flow is consistent with the direction in which the gas channel 110 guides the gas flow. Both the liquid inlet pipe 200 and the gas channel 110 guide the fluid from bottom to top. It is understood that this bottom-to-top direction is unrelated to spatial orientation and is only used for description. Figure 1 The relative positions of the components of the concentric nebulizer are as follows: the liquid sample flows from the beginning to the end of the liquid inlet tube 200, and the gas flows from the beginning to the end of the gas channel 110.

[0031] Please see Figure 1 The gas channel 110 surrounds the liquid inlet tube 200, meaning that the gas flowing out from the end of the gas channel 110 surrounds the liquid sample flowing out from the end of the liquid inlet tube 200. It can be understood that the flowing gas forms a Venturi negative pressure zone around the end of the liquid inlet tube 200, simultaneously performing circumferential shearing on the liquid sample flowing out from the liquid inlet tube 200, thereby generating a fine aerosol.

[0032] Specifically, such as Figure 3As shown, the liquid inlet tube 200 of this application includes a stabilizing section 210 at the end. The stabilizing section 210 includes a first inner cavity 211 for flowing liquid samples. The inner diameter of the first inner cavity 211 gradually increases along the flow direction of the liquid sample, that is, the radial dimension D1 at the beginning of the first inner cavity 211 is smaller than the radial dimension D2 at the end of the first inner cavity 211. In other words, the stabilizing section 210 has an expanding flow channel structure, and the radial dimension of its first inner cavity 211 smoothly transitions from D1 to D2, as shown. Figure 4 As shown, the expansion channel structure causes the liquid sample to gradually decrease in velocity and be shaped as it flows through the stable section 210. As a result, the liquid sample forms stable, non-dispersible liquid columns 300, which are easily sheared by the gas to form small and stable aerosols, thus improving the signal-to-noise ratio and reproducibility of the analysis signal.

[0033] Furthermore, since the minimum inner diameter of the first inner cavity 211 is located at the beginning of the stable section 210, this port is not the most likely physical outlet to become clogged. Particulate matter in the liquid sample can pass smoothly through the subsequent expansion-type flow channel of the first inner cavity 211 as long as it passes through this minimum inner diameter D1, reducing the risk of clogging. This design is suitable for samples containing biological cells, nanoparticle clusters, high viscosity, suspended solids, or high salt content. Simultaneously, the expansion-type flow channel of the first inner cavity 211 reduces the liquid linear velocity and shear force, facilitating the intact transport of fragile biological particles such as cells and exosomes. Therefore, the concentric nebulizer of this application has broad application adaptability, particularly suitable for complex matrix analyses that are difficult for traditional nebulizers to stably handle, such as single-particle / single-cell ICP-MS, high-salt environment samples, nanoparticle suspensions, and proteomics pretreatment solutions.

[0034] Furthermore, the axial length L of the stable segment 210 satisfies L≥5 (D2-D1), that is, the axial length of the stabilizing section 210 needs to be at least five times the radial increment of its first inner cavity 211, to provide sufficient length for the shaping of the liquid sample, so as to ensure that the liquid sample can fully develop into an axisymmetric and stable laminar flow state at the end of the stabilizing section 210, forming stable and non-dispersible liquid columns 300, which are easy to be uniformly sheared by the gas to form small and stable aerosols.

[0035] Furthermore, the radial dimension D1 at the beginning of the first inner cavity 211 is between 30 μm and 70 μm, and the radial dimension D2 at the end of the first inner cavity 211 is between 60 μm and 150 μm, with the ratio D2 / D1 satisfying a value between 1.5 and 3.0; the axial length L of the stabilizing section 210 is between 0.5 mm and 3 mm. In other words, by adjusting D2 / D1, the concentric atomizer achieves a balance between a wide flow range of the circulating liquid sample and anti-clogging performance.

[0036] In some embodiments, such as Figure 3 As shown, the cross-sectional shape of the inner wall of the stabilizing section 210 in the direction of liquid sample flow is a straight line, that is, the first inner cavity 211 expands linearly into a conical shape from the beginning to the end. At this time, the stabilizing section 210 is a linear conical expansion structure. This structure is easy to process, and the liquid flow in the flow channel is continuous, which is conducive to the stable output of the liquid flow.

[0037] In some embodiments, such as Figure 5 As shown, the cross-sectional shape of the inner wall of the stable section 210 in the direction of liquid sample flow is parabolic, that is, the first inner cavity 211 expands in a parabolic shape from the beginning to the end. This structure can more gently reduce the velocity gradient of the liquid sample flow.

[0038] In some embodiments, such as Figure 6 As shown, the cross-sectional shape of the inner wall of the stable section 210 in the direction of liquid sample flow is a stepped broken line, that is, the first inner cavity 211 expands in a stepped manner from the beginning to the end. At this time, the first inner cavity 211 is composed of multiple continuous equal diameter sections, and the inner diameter of each equal diameter section increases sequentially to form a flow channel structure that expands step by step.

[0039] In some embodiments, such as Figure 3 As shown, the liquid inlet tube 200 and the gas sleeve 100 are coaxially arranged with a gap between them, which forms the gas channel 110. In some embodiments, the gas sleeve 100 has two cavities, one of which is formed as a circular cross-section to accommodate the liquid inlet tube 200, and the other is formed as an annular cavity to serve as the gas channel 110. The annular cavity has a circular cross-section and is coaxially arranged with the circular cavity. Gas flows out from the annular cavity and uniformly covers the outer periphery of the end of the liquid inlet tube 200, thereby generating a stable and symmetrical circumferential shear force on the liquid sample.

[0040] In some embodiments, such as Figure 2 As shown, the liquid inlet tube 200 also includes an inlet section 220 located at the beginning of the liquid inlet tube 200. The inlet section 220 includes a second inner cavity 221 for introducing a liquid sample. The radial dimensions of the second inner cavity 221 are all consistent. The beginning of the inlet section 220 is connected to an external liquid sample source, and the end of the inlet section 220 is connected to the beginning of the stabilization section 210. The radial dimension of the second inner cavity 221 is the same as the radial dimension of the beginning of the first inner cavity 211. That is, the concentric nebulizer introduces the liquid sample into the stabilization section 210 through the inlet section 220.

[0041] Please see Figure 3 , Figure 5 and Figure 6The gas sleeve 100 forms a cavity, and the liquid inlet pipe 200 is coaxially disposed within this cavity. An annular gas channel 110 is formed between the inner wall of the gas sleeve 100 and the outer wall of the liquid inlet pipe 200. Gas flows through this channel to the end and uniformly coats the outer periphery of the liquid column. The outer wall of the stabilizing section 210 located at the end of the liquid inlet pipe 200 gradually approaches the inner wall of the gas sleeve 100, causing the annular gap to form a radially contracting structure at the outlet end. This structure forms an acceleration section 111 at the end of the gas channel 110. The gas velocity increases significantly when flowing through the acceleration section 111. When high-pressure gas flows through, a high-speed airflow is generated. This high-speed airflow forms a Venturi negative pressure zone around the end face of the stabilizing section 210, and simultaneously performs circumferential shearing on the columnar liquid flow exiting the stabilizing section 210, thereby generating a fine aerosol. The radial dimension of the end of the acceleration section 111 in the gas sleeve 100 is between 10 μm and 50 μm.

[0042] In some embodiments, such as Figure 3 , Figure 5 and Figure 6 As shown, a flow guide 130 is formed at the end of the gas channel 110 in the gas sleeve 100. The flow guide 130 is constructed as a flow guide structure that surrounds the annular area between the inner wall of the gas sleeve 100 and the outer wall of the liquid inlet pipe 200. Its surface is micro-conical and inclined towards the liquid inlet pipe 200 to guide the gas flow field to converge uniformly and further enhance the axial symmetry and shear stability of the airflow.

[0043] In some embodiments, the liquid inlet tube 200 and the gas sleeve 100 are integrally formed by precision micromachining or assembled and fixed by a high concentricity fixture; the coaxiality error between the liquid inlet tube 200 and the gas sleeve 100 is less than 5 μm. The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of this application. Furthermore, the embodiments and features described in the embodiments of this application can be combined with each other unless otherwise specified.

Claims

1. A concentric atomizer, characterized in that, include: A gas sleeve includes a gas channel for gas flow; a sleeve cavity is formed inside the gas sleeve. A liquid inlet tube is used to flow liquid samples. The liquid inlet tube is disposed inside the sleeve cavity and is coaxially arranged with the gas sleeve. Wherein, the direction of gas flow in the gas sleeve is the same as the direction of liquid sample flow in the liquid inlet tube, and the gas channel surrounds the liquid inlet tube; the liquid inlet tube includes a stable section, the end of which is formed as the stable section, the stable section includes a first inner cavity for flowing liquid sample, the radial dimension of the first inner cavity gradually increases along the flow direction of the liquid sample, and gas flows out from the end of the gas sleeve to perform circumferential shearing on the liquid sample flowing out from the end of the stable section.

2. The concentric atomizer according to claim 1, characterized in that, A gap is formed between the liquid inlet pipe and the gas sleeve, and the gap forms the gas channel.

3. The concentric atomizer according to claim 1, characterized in that, The inner wall of the stable section has a cross-sectional shape in the direction of liquid sample flow that is one of three: a straight line, a stepped broken line, or a parabola.

4. The concentric atomizer according to claim 1, characterized in that, The liquid inlet tube includes an inlet section, which includes a second inner cavity for introducing a liquid sample. The radial dimensions of the second inner cavity are all consistent. The end of the inlet section is connected to the beginning of the stabilizing section. The radial dimension of the second inner cavity is the same as the radial dimension of the beginning of the first inner cavity.

5. The concentric atomizer according to claim 1, characterized in that, The radial dimension D1 at the beginning of the first inner cavity is smaller than the radial dimension D2 at the end of the first inner cavity, and the axial length L of the stable segment satisfies L≥5. (D2-D1).

6. The concentric atomizer according to claim 1, characterized in that, The radial dimension D1 at the beginning of the first inner cavity is between 30 μm and 70 μm, and the radial dimension D2 at the end of the first inner cavity is between 60 μm and 150 μm, and the ratio of D2 / D1 between D1 and D2 is between 1.5 and 3.

0.

7. The concentric atomizer according to claim 1, characterized in that, An acceleration section is formed at the end of the gas channel. The acceleration section gradually contracts along the gas flow direction, and the dimension of the end of the acceleration section in the radial direction of the gas sleeve is between 10 μm and 50 μm.

8. The concentric atomizer according to claim 1, characterized in that, The gas sleeve has a flow guide at the end of the gas channel. The flow guide is inclined toward the liquid inlet pipe and can encapsulate and shear the liquid sample flowing out of the end of the liquid inlet pipe.

9. The concentric atomizer according to claim 1, characterized in that, The liquid inlet tube and the gas sleeve are integrally formed by precision micromachining or assembled and fixed by a high concentricity fixture; the coaxiality error between the liquid inlet tube and the gas sleeve is less than 5μm.

10. The concentric atomizer according to claim 1, characterized in that, The liquid inlet tube is made of fused silica, sapphire, or a chemically inert polymer.

Images