Liquid atomizing apparatus and analytical apparatus using the same

Abstract

A liquid atomizing device that continuously atomizes liquid samples of a plurality of types which are continuously supplied thereto, wherein different liquid samples are prevented from mixing with one another. This liquid atomizing device comprises: a liquid supply part that has a liquid passage; and an ultrasonic wave vibration unit that is positioned so as to be in contact with the liquid supply part, wherein the liquid supply part has a fine hole communicating the interior and the exterior of the liquid passage, the ultrasonic wave vibration unit is configured so as to apply vibrations to a liquid flowing through the liquid passage, and the liquid is discharged as fine droplets from the fine hole.

Description

Technical Field

[0001] The present disclosure relates to a liquid atomization device and an analyzer using the same.

Background Art

[0002] In an apparatus for analyzing components in a liquid sample having various sample components, a method is used in which the liquid sample is sprayed to form fine droplets, the solvent component is vaporized and removed to atomize the solute component of the sample, and the sample is introduced into an analysis unit or the like. As a typical example of an apparatus for performing analysis by such a method, there is a liquid chromatography mass spectrometer.

[0003] In a liquid chromatography mass spectrometer, a liquid sample having various components separated by a liquid chromatograph is atomized into fine droplets, and ions of the solute component are generated by charging and heating vaporization in an ion source. Then, the ionized solute component is introduced into a mass spectrometer and separated by mass-to-charge ratio to identify the components. Usually, a gas spray method is used for atomizing the liquid sample in such an analyzer. Here, the gas spray method refers to a method in which a liquid is torn apart by applying a high-speed gas jet to the liquid to form fine droplets and spray them.

[0004] In an ion source, since it is necessary to make the liquid sample into very small droplets having a diameter of about several μm, a gas spray using an ultra-high-speed gas flow with a jet velocity reaching several hundred m / s is used.

[0005] Examples of atomization devices using ultrasonic oscillators are as follows.

[0006] Patent Document 1 discloses a configuration in which an eluent of liquid chromatography is sprayed and adhered to the surface of an ultrasonic oscillator using a high-pressure gas nebulizer, and extremely fine mist is generated by the action of the ultrasonic oscillator and introduced into a mass spectrometer.

[0007] Patent Document 2 discloses a mass spectrometry system in which a solution containing a sample is placed in a sample bottle, the sample bottle is fixed on a fixture so as to be in contact with the liquid in the container, and the solution in the sample bottle is atomized by applying a voltage to an ultrasonic transducer.

[0008] Patent Document 3 discloses a spraying device comprising a single-horn type vibrator, a mesh member having countless micropores arranged on the atomizing surface of the vibrator, and a liquid supply device that supplies liquid to the atomizing surface of the vibrator, wherein the mesh member is pressed by a coil spring to contact the atomizing surface of the vibrator, and the chemical solution is atomized by the mesh member through the synergistic action of the vibrator and the mesh member. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 11-051902 [Patent Document 2] Japanese Patent Publication No. 2015-031650 [Patent Document 3] Japanese Patent Publication No. 2001-149473 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] In a liquid chromatograph-mass spectrometer, multiple types of liquid samples to be analyzed are continuously supplied from the liquid chromatograph through a small tube with a diameter of several hundred micrometers or less. The amount of each liquid sample supplied is extremely small, several hundred microliters or less. The droplet generation device used in the mass spectrometer is required to continuously form these liquid samples into minute droplets without mixing with each other, and then supply them to the analysis unit.

[0011] The droplets formed by the ultrafast gas flow of the gas spray used in the ion source are sprayed at ultrafast speeds, requiring a large amount of energy for processes such as charging and heating / vaporization, and shortening the time available for these processes. Therefore, there are challenges in stabilizing these processes.

[0012] Furthermore, because the liquid sample is atomized into tiny droplets within a high-speed, high-volume gas flow, only a small fraction of the supplied liquid sample can be introduced into the mass spectrometer, resulting in the majority of the sample being discharged unused.

[0013] In the configuration described in Patent Document 1, a large amount of gas is used because high-pressure gas is used in the nebulizer.

[0014] The apparatus described in Patent Document 2 requires the steps of placing the solution containing the sample into a sample bottle and fixing the sample bottle onto a fixture. When dealing with different types of solutions, it is thought that the number of processes required for automating the analysis will increase.

[0015] In the spraying device described in Patent Document 3, if different types of liquids are to be used, it is considered necessary to clean any remaining liquid adhering to the mesh member and the coiled spring.

[0016] The purpose of this disclosure is to prevent different liquid samples from mixing with each other in a liquid atomizing apparatus that continuously atomizes multiple types of liquid samples that are supplied continuously. [Means for solving the problem]

[0017] The liquid atomizing apparatus of this disclosure comprises a liquid supply unit having a liquid channel and an ultrasonic vibration unit positioned in contact with the liquid supply unit, wherein the liquid supply unit has micropores communicating the inside and outside of the liquid channel, and the ultrasonic vibration unit is configured to impart vibration to the liquid flowing through the liquid channel, and the liquid is released from the micropores as tiny droplets. [Effects of the Invention]

[0018] According to the present disclosure, in a liquid atomization device that continuously atomizes a plurality of types of continuously supplied liquid samples, it is possible to prevent different liquid samples from mixing with each other.

Brief Description of the Drawings

[0019] [Figure 1A] It is a cross-sectional view of the main part showing the liquid atomization device of Example 1. [Figure 1B] It is a top view of the main part showing the through-hole cross-section 3 and the ultrasonic vibration unit 6 of FIG. 1A. [Figure 1C] It is a top view of the main part showing the through-hole cross-section 3 and the ultrasonic vibration horn 7 of FIG. 1B. [Figure 2A] It is a top view showing the components of the flow path plate used in the liquid atomization device of Example 2. [Figure 2B] It is a top view showing the components of the flow path plate used in the liquid atomization device of Example 2. [Figure 2C] It is a top view showing the components of the flow path plate used in the liquid atomization device of Example 2. [Figure 2D] It is a top view showing the thin plate-shaped flow path plate of Example 2. [Figure 2E] It is a cross-sectional view showing the flow path of the flow path plate 27 of FIG. 2D. [Figure 2F] It is a partially enlarged cross-sectional view of FIG. 2E. [Figure 3A] It is a longitudinal cross-sectional view showing the liquid atomization device of Example 2. [Figure 3B] It is a longitudinal cross-sectional view of the liquid atomization device of FIG. 3A seen from above. [Figure 4A] It is a top view showing the thin plate-shaped flow path plate of Example 3. [Figure 4B] It is a cross-sectional view showing a modified example of the thin plate-shaped flow path plate of Example 3. [Figure 5A] It is a cross-sectional view of the main part showing the liquid atomization device of Example 4. [Figure 5B] It is a cross-sectional view of the main part showing a modified example of the liquid atomization device of Example 4. [Figure 6]This is a block diagram of the analytical apparatus for Example 5. [Modes for carrying out the invention]

[0020] The embodiments relating to this disclosure will be described below with reference to the drawings. [Examples]

[0021] Figure 1A is a cross-sectional view of the main part of the liquid atomizing apparatus of Example 1.

[0022] The liquid atomizing apparatus shown in this figure comprises a liquid pipe 1 (liquid supply section) for supplying a liquid sample 2, a liquid pipe support section 5 (liquid supply section support block) for supporting the liquid pipe 1, an ultrasonic vibration unit 6, an ultrasonic vibration unit support block 16 for supporting the ultrasonic vibration unit 6, and a transport gas supply pipe 10 for supplying a transport gas 11 for transporting atomized liquid droplets.

[0023] The liquid piping support section 5 has a through hole 51 for installing the ultrasonic vibration unit 6. The liquid piping 1 is positioned to cross the through hole 51. Therefore, a portion of the liquid piping 1 is not in contact with the liquid piping support section 5. In other words, a portion of the liquid piping 1 is floating inside the through hole 51. Thus, the portion of the liquid piping 1 located inside the through hole 51 constitutes a through hole crossing section 3. In this case, the through hole crossing section 3 can be said to be a liquid supply section having a liquid flow path.

[0024] Micropores are formed in the central part of the through-hole transverse portion 3.

[0025] The ultrasonic vibration unit 6 is a bolt-fastened Langevin transducer (BLT), and has a configuration in which four piezoelectric elements 8 are bolted together with electrodes in between. An ultrasonic vibration horn 7, which has a diameter narrower than the piezoelectric elements 8, is provided at the tip of the ultrasonic vibration unit 6. The vibration of the piezoelectric elements 8 is transmitted to the ultrasonic vibration horn 7, resonantly amplified, and the ultrasonic vibration horn 7 vibrates by expanding and contracting in the longitudinal direction (vertical direction in the figure).

[0026] The ultrasonic vibration unit 6 is supported on the ultrasonic vibration unit support block 16 via an ultrasonic vibration unit support member 9. The ultrasonic vibration unit support member 9 is preferably an elastic rubber ring or the like. This suppresses the transmission of vibrations from the ultrasonic vibration unit 6 to the ultrasonic vibration unit support block 16.

[0027] The ultrasonic vibration unit support block 16 is subjected to an upward force in the figure by a compression spring 17 (pressure applying part). This configures the tip of the ultrasonic vibration horn 7 to be in close contact with the back side of the micro-pore forming part of the through-hole crossing section 3. By ultrasonically vibrating the ultrasonic vibration unit 6 in this state, the vibration of the tip of the ultrasonic vibration horn 7 can be transmitted to the through-hole crossing section 3, causing the liquid sample in the through-hole crossing section 3 to be ejected as tiny droplets 15 from the micro-pores of the micro-pore forming section.

[0028] The part that applies the pressing force may be composed of an elastic body other than a spring, or it may utilize hydraulics or the like. Furthermore, it may be screwed in so that the pressing pressure can be adjusted.

[0029] A rectifier plate 12 is installed inside the ultrasonic vibration unit support block 16, and the ultrasonic vibration unit 6 is installed above it. A transport gas supply pipe 10 is connected to the lower surface of the ultrasonic vibration unit support block 16, and transport gas 11 is supplied from there.

[0030] The conveying gas 11 supplied from the conveying gas supply pipe 10 into the ultrasonic vibration unit support block 16 becomes a nearly uniform flow due to the flow straightening plate 12, flows around the ultrasonic vibration unit 6, and is then ejected from the conveying gas ejection hole 13 into the through hole 51. By flowing the conveying gas 11 around the ultrasonic vibration unit 6, a cooling effect on the ultrasonic vibration unit 6 is also obtained.

[0031] The minute droplets 15 ejected from the micropore forming section 18 are transported surrounded by the transport gas 14 ejected from the transport gas ejection holes 13. By flowing the transport gas 14 in conjunction with the spraying, the minute droplets 15 are made to flow in a constant direction, thereby suppressing the influence of surrounding airflow.

[0032] Figure 1B is a top view of the main parts showing the through-hole cross section 3 and the ultrasonic vibration unit 6 in Figure 1A.

[0033] Figure 1B shows the configuration of the ultrasonic vibration unit 6 inserted into the through-hole 51 shown in Figure 1A, and the through-hole crossing section 3, viewed from above. In other words, it shows the configuration viewed in the opposite direction to the direction of travel of the droplets sprayed from the liquid atomizing device shown in Figure 1A.

[0034] An ultrasonic vibration horn 7 is in contact with the lower side of the through-hole crossing section 3. A micro-pore forming section 18 is provided on the upper side of the through-hole crossing section 3 (part of the side surface of the liquid pipe 1 in Figure 1A). Multiple transport gas ejection holes 13 are provided around the ultrasonic vibration unit 6. Specifically, when viewed from above, 12 transport gas ejection holes 13 are arranged so as to surround the micro-pore forming section 18 of the through-hole crossing section 3.

[0035] Figure 1C is a top view of the main parts showing the through-hole cross section 3 and ultrasonic vibration horn 7 in Figure 1B.

[0036] As shown in Figure 1C, a micro-pore forming section 18 is provided on the upper side of the through-hole crossing section 3. The micro-pore forming section 18 has numerous micro-pores 19. An ultrasonic vibration horn 7 is in contact with the opposite side of the micro-pore forming section 18 (the lower side of the through-hole crossing section 3).

[0037] By applying ultrasonic vibrations generated by the ultrasonic vibration horn 7 to the through-hole crossing section 3, the liquid sample 2 (Figure 1A) supplied into the liquid pipe 1 is ejected and atomized from the micropores 19 of the micropore forming section 18. The remaining liquid 4 that is not atomized is discharged to the downstream side of the liquid pipe 1.

[0038] The diameter of the droplets ejected from the micropores 19 depends on the vibration frequency of the ultrasonic vibration unit and the narrowest diameter of the micropores 19. For example, to form minute droplets with a diameter of several micrometers, it is necessary to set the vibration frequency to around 100 kHz (tens to hundreds of kHz) and the narrowest diameter of the micropores 19 to 10 μm or less. In this example, it was confirmed that minute droplets with an average particle size (diameter) of 10 μm or less could be sprayed by setting the vibration frequency to 155 kHz and the narrowest diameter of the micropores 19 to 4 μm.

[0039] The droplets ejected by ultrasonic atomization have a slower ejection speed compared to the air spray method. In particular, tiny droplets with a small diameter are susceptible to the influence of surrounding gas convection. Therefore, in the liquid atomization device of this embodiment, as described above, the transport gas 14 is flowed in accordance with the spraying of the tiny droplets 15, so that the tiny droplets 15 flow in a constant direction and are less susceptible to the influence of surrounding airflow.

[0040] Furthermore, by using an inert gas such as nitrogen gas as the transport gas, it is possible to prevent ignition of droplets when spraying highly flammable liquids. [Examples]

[0041] The main difference between this embodiment and Embodiment 1 is the configuration of the member with the micropore-forming section. In Embodiment 1, the micropore-forming section is provided in a liquid pipe with a circular cross-section. On the other hand, in Embodiment 2, the liquid flow path is formed by stacking disc-shaped members. Considering the configuration for flowing mist-like minute droplets in one direction (for example, upward in Figure 1A) and ensuring close contact with the ultrasonic vibration horn, it is desirable to use a plate-shaped member to construct the flow path. This is because it is easier to ensure close contact with the ultrasonic vibration horn using a plate-shaped member. Furthermore, a plate-shaped member is desirable because it is easy to reduce the thickness of the plate in contact with the liquid, in other words, it is easier to transmit vibrations to the liquid.

[0042] Figure 2A is a top view showing the components of the flow path plate used in the liquid atomization apparatus of this embodiment.

[0043] This figure shows the micro-porous thin plate 20 (mesh-forming thin plate) that constitutes the upper part of the flow channel plate. The micro-porous thin plate 20 is provided with a micro-porous forming section 118, a through-hole 26 for conveying gas, and a fixing through-hole 23.

[0044] Figure 2B is a top view showing the components of the flow path plate used in the liquid atomization apparatus of this embodiment.

[0045] This figure shows the channel-forming thin plate 21 that constitutes the intermediate part of the channel plate. The channel-forming thin plate 21 is provided with channel slits 24, through holes 26 for conveying gas, and fixing through holes 23.

[0046] Figure 2C is a top view showing the components of the flow path plate used in the liquid atomization apparatus of this embodiment.

[0047] This figure shows the supply and discharge hole forming thin plate 22 that constitutes the lower part of the flow channel plate. The supply and discharge hole forming thin plate 22 is provided with a liquid supply hole 25a (supply port), a liquid discharge hole 25b (discharge port), a through hole 26 for transporting gas, and a fixing through hole 23.

[0048] As described above, the thin plate-like members shown in Figures 2A to 2C have through holes and the like that are formed by processing.

[0049] In this embodiment, a single thin plate-shaped flow channel plate with an internal liquid channel was fabricated by laminating and joining these three thin plate-shaped members. These three thin plate-shaped members have the same external dimensions. These three thin plate-shaped members are provided with six large fixing through holes 23 in the periphery and four small conveying gas through holes 26 in the center. The fixing through holes 23 and the conveying gas through holes 26 are provided at positions that coincide when the three thin plate-shaped members are stacked. The fixing through holes 23 and the conveying gas through holes 26 become through holes when they are joined together as a single unit.

[0050] The fixing through-holes 23 are used to fix and support the flow channel plate, which is made by laminating and joining the components. On the other hand, the conveying gas through-holes 26 are used to supply conveying gas around the atomized micro-droplets.

[0051] Figure 2D is a top view showing a thin, plate-like flow channel plate formed by laminating and joining the three plate materials shown in Figures 2A, 2B, and 2C.

[0052] Figure 2E shows a cross-section of the flow channel plate 27 in Figure 2D, including the flow channel.

[0053] As shown in Figure 2E, the channel plate 27 has a configuration in which a channel-forming plate 21 is sandwiched between a micro-porous plate 20 and a supply / discharge hole-forming plate 22. The channel slits 24 constitute the liquid channel. The channel slits 24 communicate with the liquid supply hole 25a and the liquid discharge hole 25b at both ends. The channel slits 24 also communicate with the micro-pores of the micro-porous section 118. In other words, the channel plate 27 has a mesh structure on the micro-porous plate 20 that constitutes one side of the wall. This allows liquid to be supplied to the liquid channel from the liquid supply hole 25a, a portion of the liquid passing through the liquid channel to be atomized as tiny droplets from the micro-pores, and the remaining liquid that is not atomized can be discharged from the liquid discharge hole 25b.

[0054] In other words, a thin, elongated liquid channel is formed inside the channel plate 27 formed by joining. The width of the liquid channel is equal to the width of the channel slit 24, and the height of the channel is equal to the thickness of the channel-forming thin plate 21. In this embodiment, 50 μm thick stainless steel plates are used as the micro-porous thin plate 20, the channel-forming thin plate 21, and the supply / discharge hole forming thin plate 22. The width of the channel slit 24 formed in the channel-forming thin plate 21 is 1 mm. Therefore, the cross-sectional area of ​​the channel is 0.05 mm². 2 This is approximately the same cross-sectional area of ​​a 1 / 16-inch tube with an inner diameter of 0.25 mm. Note that the channel height shown in Figure 2E is 50 μm, the same as the thickness of the channel-forming thin plate 21, but the thickness direction is shown enlarged compared to the width direction to clarify the channel configuration, etc.

[0055] Figure 2F is a partially enlarged cross-sectional view of Figure 2E.

[0056] Figure 2F shows a cross-section of the micropores 119 provided in the central part of the micropore-forming thin plate 20 side of the flow channel plate 27.

[0057] As shown in this figure, numerous micropores 119 are arranged on the micropore-forming thin plate 20 (the upper wall surface in the figure). In this embodiment, the micropores 119 have a narrowest diameter of 4 μm, and 388 holes are provided in a staggered arrangement at 75 μm intervals in a 1 mm wide x 2 mm long area in the center of the liquid flow path.

[0058] Various micro-hole processing methods, such as laser processing and electroforming, can be used to process the micro-holes 119. In this example, micro-hole processing was performed on a thin stainless steel plate using a YAG laser. When processing micro-holes with a YAG laser, the diameter becomes larger on the laser irradiation side.

[0059] To stably spray small droplets, it is necessary to position the narrowest part of the micropore 119 (4 μm in diameter) on the outer surface. Therefore, in this embodiment, the arrangement is as shown in Figure 2F.

[0060] As a method for creating micro-holes, electroforming allows for more precise micro-hole processing than YAG laser processing. However, electroforming is inferior to YAG laser processing in terms of productivity and cost. Furthermore, micro-hole processing in stainless steel is difficult, and in many cases, nickel-based materials are selected. Thus, when selecting a micro-hole processing method to be used in the production of micro-hole-forming thin sheets 20, it is necessary to consider the liquid sample used and the material being processed, and select a processing method that suits the purpose.

[0061] The micropore-forming thin plate 20, the channel-forming thin plate 21, and the supply / discharge hole-forming thin plate 22 are integrated by diffusion bonding. Since diffusion bonding does not use adhesives, there is no concern that impurities such as adhesives will dissolve into the liquid even if a liquid such as a solvent is flowed through the channel. However, because diffusion bonding is performed at high temperatures, there are limitations on the materials that can be used, and there is also the problem that warping is likely to occur if the types of materials being joined are different.

[0062] In this embodiment, the thickness of the micro-pore forming plate 20, the channel forming plate 21, and the supply / discharge hole forming plate 22 are all set to 50 μm. However, the thickness of the three plates does not necessarily have to be the same; they should be selected considering factors such as the height of the liquid channel cross-section and the ease of vibration when ultrasonically excited. The joining method and plate thickness should also be selected considering the liquid sample used and the material being processed, and it goes without saying that this embodiment is merely one example.

[0063] Figure 3A is a longitudinal cross-sectional view showing the liquid atomization apparatus of this embodiment.

[0064] The liquid atomizing device shown in this figure comprises an ultrasonic vibration unit 6, a thin flow channel plate 27 (liquid supply section), a flow channel plate support block 28 (liquid supply section support block) that supports the flow channel plate 27, and an ultrasonic vibration unit support block 16 that supports the ultrasonic vibration unit 6.

[0065] The flow channel plate 27 is provided with a liquid supply hole 25a and a liquid discharge hole 25b.

[0066] The flow path plate support block 28 has a donut shape (short cylindrical shape) with a through hole 151 in the center. The flow path plate support block 28 includes a lower block 28a, an upper block 28b, and a screw 28c. The flow path plate 27 is sandwiched between the lower block 28a and the upper block 28b and fixed in place by tightening the screw 28c.

[0067] The lower block 28a is connected to a liquid supply pipe 1a and a residual liquid discharge pipe 1b, allowing liquid to flow through the flow path plate 27.

[0068] In this embodiment as well, the minute droplets 15 flow in a constant direction with the transport gas 14, similar to Example 1, thus suppressing the influence of surrounding airflow.

[0069] Figure 3B is a longitudinal cross-sectional view of the liquid atomizing apparatus shown in Figure 3A, viewed from above.

[0070] As shown in Figure 3B, a flow channel plate 27 is sandwiched between the lower block 28a (Figure 3A) and the upper block 28b and secured by tightening screws 28c. The flow channel plate 27 is fixed so that its micro-porous portion 118 (mesh portion) and the conveying gas through-holes 26 provided around it for supplying the conveying gas are positioned in the through-holes of the flow channel plate support block 28.

[0071] As shown in Figure 3A, an ultrasonic vibration unit support block 16, which supports the ultrasonic vibration unit 6, is inserted into the through hole 151 of the lower block 28a. The ultrasonic vibration unit support block 16 is subjected to an upward force in the figure by a compression spring 17 or the like. This is configured so that the tip of the ultrasonic vibration horn 7 of the ultrasonic vibration unit 6 is in close contact with the center of the flow path plate 27 with a constant pressing force.

[0072] In this embodiment, the pressing force of the compression spring 17 was set to approximately 5 kN, but an appropriate pressing force can be selected considering the material and elasticity of the flow path plate 27, the contact stability of the tip of the ultrasonic vibration horn 7, and other factors.

[0073] The transport gas 11 flows around the ultrasonic vibration unit 6, passes through the transport gas ejection hole 13 (Figure 1A) similar to that in Example 1, and is ejected as transport gas 14 from four transport gas through-holes 26 provided in the flow path plate 27.

[0074] Thus, in Example 2, compared to Example 1, the conveyed gas 11 passes through the conveyed gas outlet 13 and the conveyed gas through-hole 26, so it is configured to be straightened in two stages. For this reason, in Example 2, as shown in Figure 3A, no straightening plate is provided. Of course, a straightening plate like in Example 1 may be provided.

[0075] Note that in the description of Example 2, the same configuration as in Example 1 is omitted from the explanation.

[0076] By flowing the transport gas 11 around the ultrasonic vibration unit 6, a cooling effect on the ultrasonic vibration unit 6 can also be obtained.

[0077] From the micropores of the flow channel plate 27, the liquid flowing through the liquid channel of the flow channel slit 24 is ejected by the vibration of the ultrasonic vibration horn 7. The tiny droplets of ejected liquid are surrounded by the transport gas ejected from the transport gas through-hole 26 and are transported stably.

[0078] This configuration suppresses the influence of surrounding airflow on the ejected minute droplets. Furthermore, by using an inert gas such as nitrogen gas as the transport gas, it is possible to prevent ignition of droplets when spraying highly flammable liquids. These effects are the same as in Example 1.

[0079] In this embodiment, the flow channel plate 27 is flat, making it easier to process micro-holes than the liquid piping 1 (Figure 1A) in Embodiment 1. Furthermore, in this embodiment, the contact area between the flow channel plate 27 and the tip of the ultrasonic vibration horn 7 is larger than in Embodiment 1, resulting in more stable contact. This makes it possible to stably atomize small amounts of liquid. Moreover, in this embodiment, since atomization is performed from the wall surface of the liquid flow channel (the upper surface of the flow channel plate 27), any remaining liquid that could not be atomized in the micro-hole forming section 118 can be discharged through the liquid discharge hole 25b and the remaining liquid discharge pipe 1b on the discharge pipeline side. This enables stable atomization of the continuously supplied liquid sample 2.

[0080] Furthermore, in this embodiment, since the liquid discharge hole 25b is provided near the micropore forming section 118, a configuration that reduces pressure loss in the liquid flow path can be easily realized compared to Embodiment 1. [Examples]

[0081] In this embodiment, only the differences from Embodiment 2 will be described.

[0082] Figure 4A is a top view showing the thin flow channel plate of Example 3.

[0083] In this figure, unlike the flow channel plate of Example 2 (Figure 2D), the width of the liquid flow channel of the flow channel plate 27 is varied on the upstream and downstream sides of the micro-porous section 118. Specifically, the width of the downstream flow channel 24b is made larger than the width of the upstream flow channel 24a. In other words, the width of the flow channel slits in the flow channel forming thin plate is varied on the upstream and downstream sides of the micro-porous section 118. Furthermore, the diameter of the liquid discharge hole 25b is made larger than the diameter of the liquid supply hole 25a.

[0084] This configuration makes it possible to reduce the flow resistance in the liquid flow path of the flow path plate 27, even when the liquid viscosity is high. As a result, any liquid that remains unatomized can be quickly discharged, and leakage of liquid from the micropores can be prevented.

[0085] Figure 4B is a cross-sectional view showing a modified example of the thin flow channel plate of this embodiment.

[0086] Unlike Figure 4A, this figure shows that the height of the liquid flow path in the flow channel plate 27 is different on the upstream and downstream sides of the micropore forming section 118. Specifically, the height of the downstream flow path 24b is higher than the height of the upstream flow path 24a.

[0087] To achieve this structure, the number of stacked thin plates is increased in this figure. Specifically, a flow channel plate is formed by stacking four thin plates. That is, a flow channel forming plate 21a (upper plate) and a flow channel forming plate 21b (lower plate) are stacked between the micro-porous thin plate 20 and the supply / discharge hole forming plate 22. The flow channel slits of the flow channel forming plate 21a are provided throughout the entire upstream and downstream sides of the micro-porous forming section 118. On the other hand, the flow channel slits of the flow channel forming plate 21b are provided only on the downstream side of the micro-porous forming section 118 in order to enlarge the downstream flow channel. In addition, the diameter of the liquid discharge hole 25b is larger than the diameter of the liquid supply hole 25a.

[0088] Furthermore, since the downstream side of the micropore forming section 118 is for discharging any unatomized liquid, increasing the cross-sectional area of ​​the liquid flow path has almost no effect on the atomization function. By increasing the cross-sectional area of ​​the liquid flow path downstream of the micropore forming section 118, the pressure loss within the liquid flow path can be reduced, and thus, as in the case of Figure 4A, the pressure rise in the flow path of the adjacent micropore forming section 118 can be suppressed.

[0089] In this embodiment (including modified versions), even if there is an increase in pressure during liquid delivery due to the influence of physical properties such as the viscosity of the liquid sample or an increase in the flow rate of the liquid sample, it is possible to prevent the liquid sample from leaking out of the micropores and hindering atomization by ultrasonic vibration. As a result, the continuously supplied sample liquid can be stably atomized. [Examples]

[0090] Figure 5A is a cross-sectional view of the main part of the liquid atomizing apparatus of Example 4.

[0091] In this figure, a liquid discharge hole 25b is provided downstream of the micropore forming section 118 of the thin-plate-shaped flow channel plate 27, near the ultrasonic vibration horn 7. The remaining liquid 4 that could not be atomized is discharged near the ultrasonic vibration horn 7. The ultrasonic vibration unit support member 9 is made of a rubber elastic ring to act as a liquid seal. The discharge port for the remaining liquid 4 is located on the left side in the figure.

[0092] This configuration makes it possible to reduce the pressure loss in the liquid flow path within the thin plate-shaped flow path plate 27.

[0093] In addition, residual liquid 4 may adhere to the tip of the ultrasonic vibration horn 7 or the underside of the flow path plate 27. In such cases, the residual liquid 4 may be removed by running cleaning solution through the device when it is not in use.

[0094] Figure 5B is a cross-sectional view of a modified part of the liquid atomizing apparatus of this embodiment.

[0095] In this figure, a liquid discharge hole is provided on the back side of the micropore forming section 118 in the flow channel plate 27, that is, directly above the ultrasonic vibration horn 7. In this structure, the tip of the ultrasonic vibration horn 7 and the atomized liquid sample are in direct contact. In this case, the region between the micropore forming section 118 and the ultrasonic vibration horn 7 is also included inside the liquid flow channel in the flow channel plate 27. That is, this region is the liquid flow channel 24c.

[0096] This increases atomization efficiency, meaning that the power supplied to the ultrasonic transducer can be reduced. Furthermore, since the liquid discharge hole 25b is located at the position of the micropore forming section 118, it is unlikely that the liquid pressure in the micropore forming section 118 will increase. [Examples]

[0097] Figure 6 is a block diagram showing the analytical apparatus of Example 5.

[0098] The analytical apparatus 1000 shown in this figure comprises an analytical section 100, a heating section 200, and a liquid atomizing section 300. The liquid atomizing section 300 can be a liquid atomizing device as shown in Figure 1A, etc.

[0099] The minute droplets of the liquid sample generated in the liquid atomization unit 300 are sent to the heating unit 200 and heated to generate fine particles of the solute components contained in the liquid sample, which are then analyzed in the analysis unit 100. In this case, it is desirable to ionize the minute droplets or fine particles.

[0100] The effects of the structure of this disclosure are summarized below.

[0101] The liquid atomizing apparatus of this disclosure is configured to ultrasonically atomize a liquid sample that has been delivered through a mesh hole (micropore) provided in the middle of a single liquid flow path. Therefore, even when different liquid samples are continuously delivered through a single liquid pipe, the liquids will hardly mix, and minute droplets can be continuously generated.

[0102] Furthermore, even if the type of liquid sample being delivered changes significantly, causing alterations in the atomization state and amount, stable, continuous atomization is still possible, as only the amount of unatomized liquid remains.

[0103] Since the gap between the micropores used for ultrasonic atomization and the vibrating surface is determined by the dimensions of the liquid flow path itself, there is no need to consider fluctuations in the liquid level, and stable atomization can be achieved.

[0104] Furthermore, because a portion of the liquid flow path is equipped with micropores, any unatomized residual liquid is discharged downstream of the liquid flow path, so changes in the liquid flow rate do not affect atomization.

[0105] Furthermore, since the microdroplets generated from the micropores are transported in a specific direction by the carrier gas, it is possible to prevent different types of microdroplets from mixing before being introduced into the analytical instrument.

[0106] As described above, this disclosure makes it possible to provide a novel atomization method that can form minute droplets flying at low speed from a liquid sample, and can continuously atomize small amounts of each liquid sample that are supplied continuously without mixing.

[0107] Because it is possible to form microdroplets that fly at low speed from a liquid sample, the gas flow rate used to handle the formed microdroplets can be slowed down, and the amount of gas required can also be reduced. As a result, even when applied to a mass spectrometer, the number of droplets per unit gas volume, i.e., the amount of sample components analyzed, can be increased. Furthermore, if the amount of gas introduced into the mass spectrometer remains the same, it becomes possible to analyze more sample components, thereby improving analytical sensitivity.

[0108] The liquid atomization apparatus of this disclosure can suppress the velocity of minute droplets generated from a liquid sample compared to methods such as gas spraying.

[0109] Furthermore, by configuring the system to surround slow-moving microdroplets, which are difficult to handle, with a transport gas flow during spraying, low-flight microdroplets can be handled relatively easily.

[0110] By supporting a portion of the liquid piping in a suspended state and providing fine mesh holes on the walls of the liquid piping, it is possible to stably atomize liquid samples supplied continuously at low flow rates. Because atomization is performed continuously in a single liquid piping, even if different liquid samples are continuously supplied to the same piping, they can be atomized continuously without mixing.

[0111] Furthermore, because the liquid channel is separated from the ultrasonic vibration unit, if the liquid channel becomes contaminated due to the flow of various liquids through it, only the contaminated liquid supply unit needs to be replaced, making replacement work easy.

[0112] The liquid atomizing device described herein is expected to be effective in various fields and applications where it has not been used before.

[0113] One example of a device where significant effects can be expected is the ion source for a liquid chromatograph-mass spectrometer. In a liquid chromatograph-mass spectrometer, various liquid samples containing small amounts of sample components are sent from the liquid chromatograph to the ion source of the mass spectrometer. In the ion source, these sample liquids are reduced to tiny droplets of a few micrometers in size, charged, and the solvent is heated and vaporized to generate ions of the contained sample components. These generated ions are then introduced into the mass spectrometer for component analysis.

[0114] Current ion sources utilize the air spray method to break down small amounts of sample liquid delivered from liquid chromatographs into tiny droplets with a diameter of several micrometers. Due to the small target droplet size of several micrometers for ionization efficiency and other factors, the gas velocity used in the air spray method is extremely high, exceeding several hundred m / s. Naturally, this necessitates a large gas flow rate. Furthermore, the flight speed of the formed droplets also exceeds several hundred m / s. Because charge transfer and solvent vaporization are performed on droplets flying at such high speeds, this not only requires a great deal of energy but also contributes to the instability of the ionization process itself.

[0115] By applying the liquid atomizer of this disclosure to the ion source of this liquid chromatograph-mass spectrometer, the continuously supplied sample liquid can be atomized into fine droplets at a low speed, thereby reducing gas consumption and the energy required for solvent vaporization. Furthermore, improved ionization stability can also be expected.

[0116] The liquid atomizing device described herein can be expected to produce new effects when applied to the coating of paints and the like.

[0117] The liquid atomizing apparatus disclosed herein can also be applied to inkjet printers and the like. In other words, because the continuously supplied liquid sample can be continuously atomized without mixing, it becomes possible to coat multiple colors with a single atomizing head. Conventional color coating uses three primary colors—yellow, magenta, and cyan—or four colors including black to express a variety of colors. However, to express a wider range of colors, it is effective to use various inks rather than just three primary colors or four colors including black. This is why current printing equipment uses six-color inks, for example. However, with the coating methods used in current printing, a separate coating head is required for each color used, so there is a limit to the number of colors that can be used.

[0118] In the liquid atomizing apparatus of this disclosure, liquid samples are continuously supplied and atomized into droplets with minimal mixing, making it possible to apply inks of various colors using a single liquid piping system and a single coating device. When applied to a printing apparatus, it has the potential to realize a printing apparatus capable of applying inks of various colors with a single print head.

[0119] As described above, the liquid atomizing apparatus of this disclosure can form minute droplets that fly at low speed from a liquid sample, and can provide a novel atomizing method that can continuously atomize small amounts of each liquid sample without mixing. Furthermore, by using the liquid atomizing apparatus of this disclosure, it is expected to be utilized and effective in various fields such as analytical instruments and printing coatings.

[0120] The following describes preferred embodiments of this disclosure.

[0121] In a liquid atomizing device, the ultrasonic vibration unit and the micropores are arranged so as to sandwich the liquid flow path.

[0122] The liquid channel is designed to continuously supply two or more different liquids, which are then sequentially released as tiny droplets through micropores.

[0123] The cross-sectional area of ​​the liquid channel remains constant from the upstream side of the liquid channel up to the point where micropores are provided.

[0124] The cross-sectional area of ​​a liquid channel is larger downstream of the channel where micropores are installed than upstream.

[0125] The liquid atomizing device further includes a pressing force application unit, which applies a predetermined pressing force between the liquid supply unit and the ultrasonic vibration unit.

[0126] The liquid atomizing device further includes a conveying gas supply pipe, and the minute droplets are transported in a predetermined direction by the conveying gas.

[0127] The ultrasonic vibration unit is positioned between the liquid supply unit and the transport gas supply pipe, and is configured to be cooled by the transport gas.

[0128] The liquid supply unit has a liquid supply port and a liquid discharge port.

[0129] The liquid supply unit is a pipe with a circular cross-section for the liquid flow path.

[0130] The liquid supply section is flat and has a liquid channel inside.

[0131] The liquid supply unit includes a microporous thin plate having micropores, a flow channel forming thin plate having flow channel slits, and a supply / discharge port forming thin plate having a liquid supply port and a liquid discharge port. The flow channel forming thin plate is sandwiched between the microporous thin plate and the supply / discharge port forming thin plate, and the flow channel slits constitute the liquid flow channel.

[0132] The liquid supply section has through-holes for transporting the gas, which are formed to surround the micropores.

[0133] The liquid atomizing device further includes a control unit, which adjusts at least one of the following according to the type of liquid: the vibration output, frequency, and pressure of the ultrasonic vibration unit, the liquid flow rate, etc. This makes it possible to stabilize the amount of atomization depending on the type of liquid sample supplied to the liquid flow path.

[0134] In liquid atomization systems, stable and continuous atomization is generally possible even when the type of liquid sample being delivered changes. Therefore, adjustments to the process control in response to changes in the type of liquid sample should be made as needed.

[0135] The liquid atomizing device further comprises a liquid supply unit support block that supports the liquid supply unit, the liquid supply unit support block having a through hole, the liquid supply unit being installed inside the through hole, and the ultrasonic vibration unit being inserted into the through hole.

[0136] The ultrasonic vibration unit is positioned to contact the center of the liquid supply section.

[0137] The liquid atomizing device further includes a conveying gas supply pipe for supplying the conveying gas, which is configured to pass around the ultrasonic vibration unit and be released from through holes accompanied by minute droplets.

[0138] The liquid supply unit has an outlet inside the through-hole.

[0139] The analytical device comprises a liquid atomizer and an analytical unit for analyzing the components of minute droplets.

[0140] The analytical device further includes a heating section that heats minute droplets, vaporizes the solvent components, and generates fine particles of the solute components.

[0141] The analytical device further includes an ion generation unit that ionizes fine particles. [Explanation of Symbols]

[0142] 1: Liquid piping, 1a: Liquid supply piping, 1b: Residual liquid discharge piping, 2: Liquid sample, 3: Through-hole crossing section, 4: Residual liquid, 5: Liquid piping support section, 6: Ultrasonic vibration unit, 7: Ultrasonic vibration horn, 8: Piezoelectric element, 9: Ultrasonic vibration unit support member, 10: Conveyor gas supply pipe, 11, 14: Conveyor gas, 12: Rectifier plate, 13: Conveyor gas ejection hole, 15: Microdroplet, 16: Ultrasonic vibration unit support block, 17: Compression spring, 18, 118: Micropore forming section, 19, 119: Micropore, 20: Micropore forming thin Plate, 21, 21a, 21b: Flow channel forming thin plate, 22: Supply / discharge hole forming thin plate, 23: Fixing through hole, 24: Flow channel slit, 24a: Upstream flow channel, 24b: Downstream flow channel, 24c: Liquid flow channel, 25a: Liquid supply hole, 25b: Liquid discharge hole, 26: Through hole for conveying gas, 27: Flow channel plate, 28: Flow channel plate support block, 28a: Lower block, 28b: Upper block, 28c: Screw, 51, 151: Through hole, 100: Analysis section, 200: Heating section, 300: Liquid atomization section, 1000: Analysis device.

Claims

1. A liquid supply unit having a liquid flow path, The system comprises an ultrasonic vibration unit positioned to contact the liquid supply unit, The liquid supply unit has fine holes that connect the inside and outside of the liquid flow path, The ultrasonic vibration unit is configured to impart vibration to the liquid flowing through the liquid channel, The liquid is released from the micropores as tiny droplets. It is further equipped with a conveying gas supply pipe for supplying conveying gas, The aforementioned minute droplets are conveyed in a predetermined direction by the transport gas. A liquid atomizing device wherein the ultrasonic vibration unit is positioned between the liquid supply unit and the transport gas supply pipe and is configured to be cooled by the transport gas.

2. The liquid atomizing apparatus according to claim 1, wherein the ultrasonic vibration unit and the micropore are arranged to sandwich the liquid flow path.

3. The liquid channel is capable of continuously supplying two or more different types of liquid. The liquid atomizing apparatus according to claim 1, wherein these liquids are sequentially released from the micropores as microdroplets.

4. The liquid atomizing apparatus according to claim 1, wherein the cross-sectional area of ​​the liquid flow path is constant from the upstream side of the liquid flow path to at least the position where the micropores are provided.

5. The liquid atomizing apparatus according to claim 1, wherein the cross-sectional area of ​​the liquid flow path is larger downstream of the liquid flow path than upstream of the location where the micropores are provided.

6. It is further equipped with a pressing force application section, The liquid atomizing apparatus according to claim 1, wherein the pressing force applying unit applies a predetermined pressing force between the liquid supply unit and the ultrasonic vibration unit.

7. The liquid atomizing apparatus according to claim 1, wherein the liquid supply unit has a liquid supply port and a liquid discharge port.

8. The liquid atomizing apparatus according to claim 1, wherein the liquid supply unit is a pipe whose flow path cross-section is circular.

9. The liquid atomizing apparatus according to claim 1, wherein the liquid supply unit is flat and has the liquid flow path inside it.

10. The liquid supply unit includes a thin plate having micropores, a thin plate having flow channel slits, and a thin plate having a liquid supply port and a liquid discharge port. The configuration includes a thin plate that forms micropores and a thin plate that forms supply and discharge holes, in which the thin plate that forms the flow channel is sandwiched between them. The liquid atomizing apparatus according to claim 9, wherein the flow channel slit constitutes the liquid flow channel.

11. The liquid atomizing apparatus according to claim 10, wherein the liquid supply section has through-holes for transporting gas formed so as to surround the micropores.

12. Further equipped with a control unit, The liquid atomizing apparatus according to claim 6, wherein the control unit adjusts at least one of the following according to the type of liquid: the vibration output, frequency, and pressing force of the ultrasonic vibration unit, and the flow rate of the liquid.

13. The liquid supply unit further comprises a liquid supply unit support block that supports the liquid supply unit, The liquid supply unit support block has a through hole, The liquid supply unit is installed inside the through hole, The liquid atomizing apparatus according to claim 2, wherein the ultrasonic vibration unit is inserted into the through hole.

14. The liquid atomizing apparatus according to claim 13, wherein the ultrasonic vibration unit is arranged to contact the central part of the liquid supply section.

15. The liquid atomizing apparatus according to claim 13, wherein the transport gas is configured to pass around the ultrasonic vibration unit and be discharged from the through-hole accompanied by the minute droplets.

16. The liquid atomizing apparatus according to claim 13, wherein the liquid supply unit has a discharge port inside the through hole.

17. A liquid atomizing apparatus according to any one of claims 1 to 16, An analytical apparatus comprising an analytical unit for analyzing the components of the aforementioned minute droplets.

18. The analytical apparatus according to claim 17, further comprising a heating unit that heats the aforementioned minute droplets to vaporize the solvent components and generate fine particles of the solute components.

19. The analytical apparatus according to claim 18, further comprising an ion generating unit for ionizing the aforementioned fine particles.

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