A flame atomizer and trace sodium online monitoring system

Abstract

The present invention discloses a flame atomizer and an online monitoring system for trace sodium, which belong to the technical field of online analytical instruments. The flame atomizer includes an atomizer chamber, a first chamber, a second chamber and a third chamber which are connected in sequence; the atomizer chamber is provided with a sampling capillary, an oil-free compressed air inlet and an atomizer chamber outlet, and the atomizer chamber outlet connects the atomizer chamber and the first chamber; the first chamber is provided with a fuel gas inlet and an impact ball, and the impact ball is arranged opposite to the atomizer chamber outlet; the second chamber is provided with a high-temperature gas inlet, and the second chamber is filled with phase-change heat storage balls; a burner is provided above the third chamber, and the burner is provided with a purified air inlet, and the annular center porous burner head of the burner is connected to the third chamber. This technical solution can effectively solve the technical problems of low atomization rate, low flame temperature, unstable flame combustion, etc. existing in the existing flame atomizer.

Description

Technical Field

[0001] The invention relates to the technical field of online analytical instruments, and in particular to a flame atomizer and a trace sodium online monitoring system. Background Art

[0002] The flame atomizer is an important component of the spectrometer. It is a device that uses flame to convert ions in the test solution into atomic vapor. It has a significant impact on the sensitivity and repeatability of spectral (atomic absorption, atomic fluorescence spectroscopy and flame atomic emission spectroscopy) measurements. The traditional flame atomizer consists of three parts: an atomizer, a premixing chamber and a burner. In the flame atomization process, the liquid sample is atomized and brought into the flame for atomization by mixing the combustion-supporting gas (air or oxygen) and the fuel gas (gas fuel). The introduction of the test solution into the flame and its atomization undergoes a series of complex physical and chemical processes, which include the desolvation, evaporation, and dissociation of the mist particles. During the dissociation process, most of the ions dissociate into gaseous atoms.

[0003] At present, the second-order differential flame emission spectrometer has adopted the traditional flame atomizer. The burner uses air at room temperature (ambient temperature) to assist combustion. The flame temperature is low and unstable, resulting in unstable flame combustion and low atomization efficiency. At the same time, the traditional atomizer usually adopts a pneumatic concentric atomizer for sample injection. This atomizer uses compressed air with a certain pressure as a combustion aid to enter the atomizer. The water sample is ejected at high speed from around the injection capillary, and the combustion-supporting gas introduced is scattered into droplets (aerosol). The more water samples are atomized, the finer the droplets are, the easier they are to dry, melt, and vaporize, and the more free atoms are generated, and the higher the sensitivity of the spectrometer. However, the atomization efficiency of this traditional atomizer can only reach about 10% at most. Since less than 10% of the test solution is atomized, the sensitivity of the second-order differential flame emission spectrometer is low. In order to improve the sensitivity of the second-order differential flame emission spectrometer, the invention patent: 2011.1.0279428.0 uses oxygen-enriched acetylene flame, and the utility model: ZL 201620667866.2 uses hydrogen-oxygen flame to increase the flame temperature. However, the above measures are prone to flashback explosion accidents due to the high combustion speed of oxygen-enriched acetylene flame and hydrogen-oxygen flame, threatening the safety of users and instruments. Summary of the invention

[0004] The main purpose of the present invention is to propose a flame atomizer and an online monitoring system for trace sodium, which aims to solve the technical problems of the existing flame atomizer, such as low atomization efficiency, low flame temperature, unstable flame combustion, etc.

[0005] To achieve the above-mentioned purpose, the present invention provides a flame atomizer, which includes an atomizer chamber, a first chamber, a second chamber and a third chamber which are connected in sequence; the atomizer chamber is provided with an injection capillary, an oil-free compressed air inlet and an atomizer chamber outlet, and the atomizer chamber outlet is connected with the atomizer chamber and the first chamber; the first chamber is provided with a gas inlet and an impact ball, and the impact ball is arranged opposite to the atomizer chamber outlet; the second chamber is provided with a high-temperature air inlet, and the second chamber is filled with phase change heat storage balls; a burner is provided above the third chamber, the burner is provided with a purified air inlet, and the annular central porous burner head of the burner is connected with the third chamber.

[0006] Optionally, a separation flange is provided between the first chamber and the second chamber, and between the second chamber and the third chamber, and the separation flange is provided with a through hole to respectively connect the first chamber and the second chamber, and the second chamber and the third chamber.

[0007] Optionally, the flame atomizer further comprises an electrolytic high-purity water hydrogen generator, and the outlet of the electrolytic high-purity water hydrogen generator is connected to the fuel gas inlet.

[0008] Optionally, the flame atomizer also includes an oil-free air compressor, a precision air heater, a membrane dryer and an air filter purifier. A pressure regulating valve is provided at the outlet of the oil-free air compressor, the outlet of the pressure regulating valve is connected to the inlet of the membrane dryer, the outlet of the membrane dryer is connected to the oil-free compressed air inlet via a first isolation valve, the outlet of the membrane dryer is connected to the inlet of the precision air heater via a second isolation valve, the outlet of the precision air heater is connected to the high-temperature gas inlet, and the outlet of the membrane dryer is connected to the purified air inlet via the air filter purifier.

[0009] Optionally, the first chamber is also provided with a waste liquid discharge outlet, and one side of the third chamber is also provided with an explosion-proof membrane.

[0010] Optionally, a vacuum annular cavity is provided in the side wall of the second chamber to achieve heat preservation treatment of the second chamber.

[0011] Optionally, the phase-change heat storage ball includes a stainless steel spherical shell with a cavity, and the stainless steel spherical shell is provided with a feeding sealing port to fill the cavity of the stainless steel spherical shell with phase-change heat storage material.

[0012] Optionally, the phase change temperature of the phase change thermal storage material is 400°C.

[0013] In addition, to achieve the above-mentioned purpose, the present invention also provides an online monitoring system for trace sodium, which includes a sampling-calibration component, a second-order differential flame emission spectrometer and the above-mentioned flame atomizer, wherein the sampling-calibration component is used to, under the control of the second-order differential flame emission spectrometer, successively and stably transport the calibration high-purity water, the standard water sample and the water sample to be measured to the atomizer chamber of the flame atomizer through the sampling capillary; the flame atomizer is used to, under the control of the second-order differential flame emission spectrometer, successively atomize and flame atomize the calibration high-purity water, the standard water sample and the water sample to be measured transported by the sampling-calibration component to form a flame radiating a 589.0nm sodium spectrum; the second-order differential flame emission spectrometer is used to control the operation of the sampling-calibration component and the flame atomizer in real time, and perform data analysis and processing on the flame formed by the flame atomizer in real time to obtain corresponding test results.

[0014] Optionally, the injection-calibration component includes a high-position high-purity water cup for calibration, a high-position standard water sample cup for calibration, a calibration switching solenoid valve, a water inlet pipe for the water sample to be measured, a water sample inlet regulating solenoid valve, an injection three-way valve, a water sample inlet pipe and a constant liquid level overflow water sample cup. The water inlet pipe for the water sample to be measured is connected to the first inlet of the injection three-way valve via the water sample inlet regulating solenoid valve, the outlet of the high-position high-purity water cup for calibration and the outlet of the high-position standard water sample cup for calibration are respectively connected to the second inlet of the injection three-way valve via the calibration switching solenoid valve, one end of the water sample inlet pipe is connected to the outlet of the injection three-way valve, the other end of the water sample inlet pipe is inserted into the constant liquid level overflow water sample cup, the outer end of the injection capillary is inserted into the constant liquid level overflow water sample cup, and the outlet of the water sample inlet pipe is lower than the inlet of the injection capillary.

[0015] Optionally, the sampling-calibration assembly further includes a fixed groove and an overflow water collecting cup, and the constant liquid level overflow water sample cup is installed in the overflow water collecting cup through the fixed groove.

[0016] Optionally, the second-order differential flame emission spectrometer includes: a photoelectric sensor component, which is used to quickly scan the characteristic spectrum line of sodium and automatically deduct the background interference of the flame to generate a second-order differential modulated sodium spectrum, so as to be received and excited by the photomultiplier tube to generate a second-order differential frequency modulated current, and the second-order differential frequency modulated current is demodulated and amplified by a phase-locked amplifier and then output to a data acquisition component; a data acquisition component, which is used to collect analog signals of the second-order differential frequency modulated current, and convert them into digital signals and output them to an embedded industrial computer component for real-time monitoring and control; an embedded industrial computer component, which is used to control the operation of the sampling-calibration component, the flame atomizer, the photoelectric sensor component and the data acquisition component in real time, and perform statistical analysis and processing on the data collected by the data acquisition component in real time to obtain test results.

[0017] The flame atomizer and trace sodium online monitoring system provided by the present invention, wherein the flame atomizer comprises an atomizer chamber, a first chamber, a second chamber and a third chamber which are sequentially connected and arranged. The atomizer chamber is provided with a sampling capillary, an oil-free compressed air inlet and an atomizer chamber outlet. When in use, the outer end of the sampling capillary can be inserted into the constant liquid level overflow water sample cup. At this time, the oil-free compressed air connected through the oil-free compressed air inlet forms a "negative pressure field" in the atomizer chamber, and the water sample to be measured (or high-level high-purity water for calibration, or high-level standard water sample for calibration) in the constant liquid level overflow water sample cup can be sucked into the atomizer chamber through the sampling capillary, so as to complete the atomization and preliminary mixing process of the water sample in the atomizer chamber and then spray it out through the atomizer chamber outlet. The first chamber is provided with a gas inlet and an impact ball, and the impact ball is arranged directly opposite to the atomizer chamber outlet. The impact ball can smash the droplets sprayed from the atomizer chamber outlet, so that the aerosol mist particles are finer and more uniform. At the same time, the fuel gas connected through the gas inlet can be mixed with the aerosol sprayed from the outlet of the atomizer chamber in the first chamber and then enter the second chamber. The second chamber is provided with a high-temperature gas inlet, and the second chamber is filled with phase-change heat storage balls. The high-temperature gas enters through the high-temperature gas inlet and heats the phase-change heat storage balls. In this way, the "fog particles" of the aerosol sprayed from the atomizer chamber and crushed by the impact ball are fully in contact with the high-temperature phase-change heat storage balls, and the "fog particles" are heated and completely vaporized, and the atomization efficiency can reach 100%. A burner is arranged above the third chamber, and the burner is provided with a purified air inlet, and the annular center porous burner head of the burner is connected to the third chamber. The purified air (combustion-supporting gas) with stable pressure can be connected through the purified air inlet, so that the completely atomized temperature-stable high-temperature mixed gas coming out of the second chamber enters the third chamber, and can be ignited above the annular center porous burner head of the burner to form a flame, radiating a sodium characteristic spectrum of 589.0nm with stable spectral line intensity. It can be seen that the present technical solution can effectively solve the technical problems existing in the existing flame atomizers, such as low atomization rate, low flame temperature, unstable flame combustion, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 This is an overall structural diagram of the phase-change heat storage constant temperature flame atomizer provided in Example 1 of the present invention.

[0020] Figure 2 for Figure 1 Schematic diagram of the structure of the phase change heat storage ball of the flame atomizer shown.

[0021] Figure 3 This is a structural block diagram of the trace sodium online monitoring system provided in Example 2 of the present invention.

[0022] Figure 4 for Figure 3 Schematic diagram of the structure of the sampling-calibration component of the trace sodium online monitoring system shown.

[0023] Figure 5 for Figure 3 The structural block diagram of the embedded industrial computer of the second-order differential flame emission spectrometer of the trace sodium online monitoring system is shown.

[0024] Figure 6 for Figure 5 The flowchart of the specific calibration process of the calibration module of the embedded industrial computer shown in FIG.

[0025] Figure 7 This is the Roman gold relationship curve based on the principle of atomic emission spectroscopy. DETAILED DESCRIPTION

[0026] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0027] Embodiment 1

[0028] like Figure 1As shown, the first embodiment of the present invention provides a flame atomizer II, which includes an atomizer chamber 110, a first chamber 120, a second chamber 130 and a third chamber 140 which are connected in sequence. The atomizer chamber 110 is provided with a sampling capillary 111, an oil-free compressed air inlet 112 and an atomizer chamber outlet 113, and the atomizer chamber outlet 113 connects the atomizer chamber 110 with the first chamber 120. The first chamber 120 is provided with a gas inlet 121 and an impact ball 122, and the impact ball 122 is arranged opposite to the atomizer chamber outlet 113. The second chamber 130 is provided with a high-temperature gas inlet 131, and the second chamber 130 is filled with a phase-change heat storage ball 132. A burner 141 is provided above the third chamber 140, and the burner 141 is provided with a purified air inlet 142, and the annular center porous burner head of the burner 141 is connected to the third chamber 140.

[0029] In this embodiment, Figure 1 As shown, a separation flange 10 is provided between the first chamber 120 and the second chamber 130, and between the second chamber 130 and the third chamber 140, and the separation flange 10 is provided with a through hole 11 to respectively connect the first chamber 120 and the second chamber 130, and the second chamber 130 and the third chamber 140. In this way, through the separation flange 10 with the through hole 11, the first chamber 120, the second chamber 130, and the third chamber 140 can be separated and formed, and the three can be partially connected in sequence.

[0030] like Figure 2 As shown, the phase-change heat storage ball 132 includes a stainless steel spherical shell 1321 with a cavity, and a charging seal 1322 is provided on the stainless steel spherical shell 1321 to fill the cavity of the stainless steel spherical shell 1321 with a phase-change heat storage material 1323. Specifically, the stainless steel spherical shell 1321 is a stainless steel hollow ball with a diameter of 8mm-16mm, and the charging seal 1322 is sealed by a stainless steel plug coated with high-temperature resistant glue to fill the outer hole, and the volume of the phase-change heat storage material 1323 is 2 / 3-3 / 4 of the volume of the stainless steel spherical shell. The phase-change heat storage material 1323 is a solid-solid composite phase-change material, and the phase change temperature of this solid-solid composite phase-change heat storage material is designed to be 400°C. The second chamber 130 is a "phase change heat storage atomization bed" filled with phase change heat storage balls 132. The aerosol mist particles sprayed out from the atomizer chamber 110 and crushed by the impact ball 122 are fully in contact with the high-temperature phase change heat storage balls 132 and are completely atomized, and the atomization efficiency can reach 100%.

[0031] like Figure 1As shown, the flame atomizer II in this embodiment also includes an electrolytic high-purity water hydrogen generator 150, an oil-free air compressor 160, a precision air heater 170, a membrane dryer 180 and an air filter purifier 190. Among them, the outlet of the electrolytic high-purity water hydrogen generator 150 is connected to the gas inlet 121, and the gas inlet 121 is connected to high-purity hydrogen as fuel gas, which can further ensure the combustion stability of its burner. A pressure regulating valve 12 is set at the outlet of the oil-free air compressor 160, and the outlet of the pressure regulating valve 12 is connected to the inlet of the membrane dryer 180. The outlet of the membrane dryer 180 is connected to the oil-free compressed air inlet 112 through the first isolation valve 13, and the outlet of the membrane dryer 180 is connected to the inlet of the precision air heater 170 through the second isolation valve 14. The outlet of the precision air heater 170 is connected to the high-temperature gas inlet 131, and the outlet of the membrane dryer 180 is connected to the purified air inlet 142 through the air filter purifier 190. That is, the "purified air" connected to the purified air inlet 142 in this embodiment is the clean air obtained after the dry air output from the outlet of the membrane dryer 180 passes through the air filter purifier 190 (specifically a 0.1μ precision filter) to further remove the solid and liquid particles in the air. This "purified air" enters the annular channel of the annular central porous burner head from the purified air inlet 142 at the bottom of the burner 141. Since the pressure of the "purified air" is higher than the pressure of the combustion mixed gas in the third chamber 140, a slightly positive pressure annular protective cover will be formed around the flame torch that radiates the sodium element emission spectrum formed above the burner 141. This annular protective cover has the function of automatically diffusing to the periphery of the flame, and can effectively prevent various trace interference components (salt mist and dust particles) in the surrounding space environment from entering the atomized flame center, and can achieve the purpose of performing trace analysis under normal measurement environment conditions and obtaining stable measurement results.

[0032] In addition, if Figure 1 As shown, the first chamber 120 is also provided with a waste liquid outlet 123 to discharge waste liquid. An explosion-proof membrane 143 is also provided on one side of the third chamber 140 to ensure the safety performance of the third chamber 140 when the burner 142 is working. A vacuum annular cavity 133 is provided in the side wall of the second chamber 130 to achieve heat preservation treatment of the second chamber 130.

[0033] During operation, the oil-free air compressor 160 outputs stable oil-free compressed air after pressure regulation by the pressure regulating valve 12 and enters the atomizer chamber 110 through the oil-free compressed air inlet 112, forming a "negative pressure field" in the atomizer chamber 110 to inhale the water sample to be measured (or high-purity water for calibration, or high-standard water sample for calibration) through the sampling capillary 111, and completes the atomization and preliminary mixing process of the water sample in the atomizer chamber 110, and then sprays out from the atomizer chamber outlet 113. At this time, the impact ball 122 in the first chamber 120 can smash the droplets sprayed from the atomizer chamber outlet 113, making the aerosol particles finer and more uniform. At the same time, the high-purity hydrogen output by the electrolytic high-purity water hydrogen generator 150 enters the first chamber 120 from the gas inlet 121, mixes with the aerosol sprayed from the atomizer chamber 110, and enters the second chamber 130. Since the second chamber 130 is a "phase change thermal storage atomization bed" filled with phase change thermal storage balls 132, the "fog particles" of the aerosol ejected from the atomizer chamber 110 and crushed by the impact ball 122 are fully in contact with the high-temperature phase change thermal storage ball 130, and the "fog particles" are heated and completely vaporized, and the atomization efficiency can reach 100%. Finally, the completely atomized temperature-stable high-temperature mixed gas coming out of the second chamber 130 enters the third chamber 140, and ignites above the annular center porous burner head of the burner 141 to form a flame, radiating a sodium characteristic spectrum of 589.0nm with stable spectral line intensity.

[0034] In addition, when using the above-mentioned flame atomizer II, the following operations can also be performed: (1) Start the oil-free air compressor 160, adjust the pressure regulating valve 12 so that the outlet pressure of the oil-free air compressor 160 is 0.25MP, close the first isolation valve 13 and open the second isolation valve 14 to heat the compressed air through the precision air heater 170, and control the outlet temperature of the precision air heater 170 to 400±5℃; (2) The high-temperature air enters the phase change heat storage atomizing bed (i.e., the second chamber 130) through the high-temperature gas inlet 131, and the high-temperature air contacts the phase change heat storage ball 132 and heats the phase change heat storage ball 132; until the hot air temperature at the burner 141 outlet Stabilize at the phase change temperature + 5 ° C (3) close the second isolation valve 14 and open the first isolation valve 13 to allow the combustion-supporting gas to enter the nebulizer chamber 110 through the combustion-supporting gas inlet (i.e., the oil-free compressed air inlet 112) to form a "negative pressure field" in the nebulizer chamber 110 to allow the water sample to be measured to enter the nebulizer chamber 110 through the sampling capillary 111 to be atomized into fine droplets and enter the phase change heat storage atomization bed (i.e., the second chamber 130) to contact and atomize with the constant temperature phase change heat storage ball 132. The hot constant temperature high-temperature mixed gas ignites above the outlet of the burner 141 to form a temperature-stable high-temperature flame and radiate the characteristic emission spectrum of the Na element at 589.0nm.

[0035] Compared with the prior art, the advantages of the embodiments of the present invention are: (1) The atomization efficiency is as high as 100%, while the atomization efficiency of the traditional flame atomic absorption atomizer is generally less than 10%. Therefore, the sensitivity of the trace sodium analysis of the embodiments of the present invention is improved by one order of magnitude compared with the second-order differential flame emission spectrometer using the traditional concentric atomizer. (2) The use of the phase-change thermal storage atomization bed realizes the high-temperature preheating of the combustion-supporting gas, increases the atomization temperature, and improves the sensitivity and detection limit of the analysis. (3) The use of the phase-change thermal storage atomization bed realizes the constant temperature and high temperature of the premixed gas, so that the temperature of the atomization flame is stable and the repeatability of the measurement results is improved. (4) The detection limit of trace sodium in high-purity water measured by the second-order differential flame emission spectrometry has reached an advanced level of less than 0.1 μg / L. (5) Compared with the graphite furnace atomic absorption spectrometer and the inductively coupled plasma emission spectrometer (ICP), it has the obvious advantages of simple equipment, simple operation and low analysis cost.

[0036] Embodiment 2

[0037] like Figure 3 As shown, the second embodiment of the present invention provides an online monitoring system for trace sodium, which includes a sampling-calibration component I, a flame atomizer II, and a second-order differential flame emission spectrometer III. Among them, the sampling-calibration component I is mainly used to continuously and stably transport the calibration high-purity water, standard water sample and water sample to be measured to the atomizer chamber 110 of the flame atomizer II through the sampling capillary 111 under the control of the second-order differential flame emission spectrometer III. The flame atomizer II is mainly used to atomize and flame atomize the calibration high-purity water, standard water sample and water sample to be measured transported by the sampling-calibration component I in turn under the control of the second-order differential flame emission spectrometer III, forming a flame that radiates a 589.0nm sodium spectrum. The second-order differential flame emission spectrometer III is mainly used to control the operation of the sampling-calibration component I and the flame atomizer II in real time, and to perform data analysis and processing on the flame formed by the flame atomizer II in real time to obtain corresponding test results.

[0038] In this embodiment, if Figure 4As shown, the sampling-calibration component I includes a high-level high-purity water cup 201 for calibration, a high-level standard water sample cup 202 for calibration, a calibration switching solenoid valve 203, a water sample inlet pipe 204 to be measured, a water sample inlet regulating solenoid valve 205, a sampling three-way valve 206, a water sample inlet pipe 207 and a constant liquid level overflow water sample cup 208. The water sample inlet pipe 204 to be measured is connected to the first inlet of the sampling three-way valve 206 via the water sample inlet regulating solenoid valve 205. The high-level high-purity water cup for calibration The outlet of 201 and the outlet of the calibration high-level standard water sample cup 202 are respectively connected to the second inlet of the injection three-way valve 206 through the calibration switching solenoid valve 203, one end of the water sample inlet pipe 207 is connected to the outlet of the injection three-way valve 206, the other end of the water sample inlet pipe 207 is inserted into the constant liquid level overflow water sample cup 208, the outer end of the injection capillary 111 is inserted into the constant liquid level overflow water sample cup 208, and the outlet of the water sample inlet pipe 207 is lower than the inlet of the injection capillary 111. During operation, the calibration high-level high-purity water cup 201 is filled with calibration high-level high-purity water, the calibration high-level standard water sample cup 202 is filled with standard water sample (i.e., 10μg / L sodium standard water sample), and the water sample inlet pipe 204 to be measured is connected to the water sample to be measured. By switching the calibration switching solenoid valve 203, the water sample inlet regulating solenoid valve 205 and the injection three-way valve 206 respectively, the high-purity water for calibration, the standard water sample and the water sample to be measured can be continuously and stably transported to the nebulizer chamber 110 of the flame atomizer II via the water sample inlet pipe 207, the constant liquid level overflow water sample cup 208 and the injection capillary 111.

[0039] Specifically, Figure 4As shown, the sampling-calibration component I also includes a fixed groove 209 and an overflow water collection cup 210, and the constant liquid level overflow water sample cup 208 is installed in the overflow water collection cup 210 through the fixed groove 209. The calibration switching solenoid valve 203 is a two-position three-way solenoid valve, and the three channels are respectively connected to the calibration high-level high-purity water cup 201, the calibration high-level standard water sample cup 202 and the sampling three-way valve 206. The other two channels of the sampling three-way valve 206 connected to the calibration switching solenoid valve 203 are respectively connected to the water sample inlet regulating solenoid valve 205 and the water sample inlet pipe 207. Among them, the calibration high-level high-purity water cup 201 and the calibration high-level standard water sample cup 202 can be an open bottom-opening polyethylene (PE) container with a capacity of 1000mL, the bottom of the container is a conical funnel structure, and the height difference between the bottom of the container and the inlet of the sampling capillary 111 is a second preset height difference (preferably about 1000mm). High-purity water for calibration refers to high-purity water used to prepare standard water samples for calibration. The outlet of the water sample inlet pipe 207 is lower than the inlet of the sampling capillary 111 by a first preset height difference (preferably about 10 mm), and the sampling capillary 111 is connected to the atomizer chamber 110 of the flame atomizer from the bottom of the constant liquid level overflow water sample cup 208. The constant liquid level overflow water sample cup 208 is preferably a 125mL standard PE narrow-mouth sampling bottle placed in a cylindrical fixed groove 209 in the center of the open overflow water collection cup 210. The size of the cylindrical fixed groove 209 is: Ф52×50 (H), and the water sample flow rate flowing through the constant liquid level overflow water sample cup 208 is designed to be 40mL / min-60mL / min. The overflow port of the constant liquid level overflow water sample cup 208 is the bottle mouth of a 125mL standard PE narrow-mouth sampling bottle. The overflow of the constant liquid level overflow water sample cup 208 serves to keep the liquid column height of the water sample at the entrance of the injection capillary 111 stable during the measurement process. This stable water sample height can stabilize the static pressure at the entrance of the injection capillary 111. Maintaining the stable static pressure at the entrance of the injection capillary 111 can ensure the stability of the water sample lifting amount entering the atomizer under the condition of stable carrier gas (hydrogen and oxygen mixed gas) pressure. The stability of the water sample lifting amount can ensure the stability of the flame combustion temperature during the measurement process, thereby ensuring the stability and repeatability of the measurement results. At the same time, the water sample overflows from the top of the constant liquid level overflow water sample cup 208 to ensure the real-time measurement of the water sample in the constant liquid level overflow water sample cup 208. The design ensures that the outlet of the water sample inlet pipe 207 is lower than the inlet of the injection capillary 111 by a first preset height difference (about 10 mm), which can ensure the real-time nature of the water sample entering the injection capillary 111, thereby ensuring the real-time representativeness of the measurement data.

[0040] The second-order differential flame emission spectrometer (III) specifically includes a photoelectric sensor component, a data acquisition component, and an embedded industrial computer component. Among them, the photoelectric sensor component is mainly used to quickly scan the characteristic spectrum of sodium and automatically remove the background interference of the flame to generate a second-order differential modulated sodium spectrum, which is received and excited by the photomultiplier tube to generate a second-order differential frequency modulated current. The second-order differential frequency modulated current is demodulated and amplified by the phase-locked amplifier and then output to the data acquisition component. The data acquisition component is mainly used to collect the analog signal of the second-order differential frequency modulated current, and convert it into a digital signal and output it to the embedded industrial computer component for real-time monitoring and control. The embedded industrial computer component is mainly used to control the operation of the sampling-calibration component I, the flame atomizer II, the photoelectric sensor component and the data acquisition component in real time, and perform statistical analysis and processing on the data collected by the data acquisition component in real time to obtain the test results.

[0041] The embedded industrial computer components specifically include an embedded industrial computer (host) and a resistive touch screen (display). The embedded industrial computer is responsible for processing and displaying the digital signals transmitted by the slave computer. The host and the slave communicate via USB. In this way, users can write various functional programs on the host computer to effectively query and analyze the data in the file, which is conducive to the long-term normal operation and inspection of the analysis and measurement process. Figure 5 As shown, the embedded industrial computer includes a system setting module 301 , an ignition module 302 , a calibration module 303 , a measurement module 304 and a data processing module 305 .

[0042] System setting module 301: used to set the characteristic spectral line wavelength of the automatic scanning second-order differential precision grating monochromator to 589.0nm; also used to set the ripple coefficient of the high-voltage DC voltage output by the negative high-voltage module of the photomultiplier tube to be less than 0.005%, the maximum drift to be less than ±0.03% / h, and the negative high-voltage DC voltage value. From the operational level, after the user turns on the host power supply, the monochromator power supply, the silicon nitride ignition power supply and the computer power supply, the USB connection cable is used to connect the industrial computer with the lower computer (host), and the computer with the monochromator. Start the icon of the trace sodium online monitoring software, and complete the system setting steps in the software human-machine interface dialog box. The system setting parameters include but are not limited to system time setting, characteristic spectral line wavelength setting 589.0nm, photomultiplier tube negative high voltage setting, and user name setting. After completing the setup, the computer performs a system test. The test parameters include but are not limited to: output pressure of the electrolytic high-purity water hydrogen generator, flame sensor status signal, silicon nitride automatic ignition power switch status, oil-free air compressor output pressure signal, calibration status signal, calibration switching solenoid valve status signal, injection three-way valve status signal, water sample inlet adjustment solenoid valve status signal, etc.

[0043] Ignition module 302: used to start the electrolytic high-purity water hydrogen generator 150, and start the ignition solenoid valve after detecting that the output pressure of the electrolytic high-purity water hydrogen generator 150 reaches a preset ignition threshold and the automatic ignition power supply is normal.

[0044] Calibration module 303: After detecting that the flame sensor status signal is normal, control the sampling-calibration component I to continuously and stably deliver the calibration high-purity water and calibration standard water sample to the flame atomizer II, and send a data acquisition instruction to the data acquisition component to obtain the measurement data of the calibration water sample collected by the data acquisition component. Specifically,

[0045] It should be noted that before the calibration module 303 starts the calibration process, the calibration high-level high-purity water cup 201 and the calibration high-level standard water sample cup 202 need to be filled with high-purity water and (10 μg / L) sodium standard water sample respectively. Figure 6 As shown, the specific calibration process of the calibration module 303 includes:

[0046] S110, close the water sample inlet regulating solenoid valve 205.

[0047] S120, open the calibration switching solenoid valve 203 and tangentially calibrate the high-position high-purity water cup 201.

[0048] S130 , open the three-way injection valve 206 to allow high-purity water to flow into the constant liquid level overflow water sample cup 208 .

[0049] Specifically, after opening the sampling three-way valve 206, high-purity water flows into the constant liquid level overflow water sample cup 208 through the sampling water inlet pipe 207, and the high-purity water from the calibration high-position high-purity water cup 201 is automatically sucked into the nebulizer chamber 110 through the sampling capillary 111 to complete the process of atomization, mixing, and droplet separation, and then ignites above the outlet of the annular central porous burner head of the burner 141 to form a flame radiating 589.0nm sodium spectrum.

[0050] S140: Send a data acquisition instruction to the data acquisition component, and obtain the measurement result of the high-purity water collected by the data acquisition component.

[0051] Specifically, the embedded industrial computer sends a collection instruction to the single-chip microcomputer of the data acquisition component. The single-chip microcomputer collects the DC analog signal from the low-pass filter of the micro-current phase-locked amplifier, and converts it into a digital signal through an A / D converter and sends it to the embedded industrial computer for storage and further processing.

[0052] S150, open the calibration switching solenoid valve 203 to tangentially calibrate the high-level standard water sample cup 202, and after flushing for a preset time, obtain the measurement result of the standard water sample collected by the data acquisition component.

[0053] Specifically, after the high-purity water sampling reading is completed, the calibration switching solenoid valve 203 is tangentially calibrated to the high-level standard water sample cup 202, and the 10μg / L sodium standard water sample flows into the constant liquid level overflow water sample cup 208. After flushing for 3 minutes, data collection begins to complete the data collection of the 10μg / L sodium standard water sample.

[0054] S160, close the calibration switching solenoid valve 203, and open the water sample inlet regulating solenoid valve 205.

[0055] S170. Obtain the calibration regression line and the sodium background concentration of high-purity blank water.

[0056] Specifically, the sodium ions in the water sample are atomized in the high-temperature flame and excited to radiate the "characteristic spectrum line" of the sodium atoms. Under the condition of extremely low (trace) sodium ion concentration, the intensity of the spectrum line is proportional to the concentration of sodium ions in the sample. The Roman gold formula (such as Figure 7 shown).

[0057] The physical meaning of the Roman gold formula is that the calibration curve of the atomic emission spectrum must be a straight line passing through the origin (when and only when the sodium ion concentration in the water sample is zero, the measured value of the spectral line intensity can be zero), which provides a theoretical basis for the measurement and calibration of the atomic emission spectrum without the need to prepare "sodium-free water". In fact, under the existing technical conditions, real "sodium-free water" does not exist in the laboratory. Recognizing and using "sodium-free water" is a prerequisite for atomic absorption and liquid chromatography to measure trace sodium.

[0058] Right now:

[0059] y=f b x (1)

[0060] x=y / f b (2)

[0061] Where: x is the actual concentration of sodium in the water sample (μg / L);

[0062] y is the spectral line intensity value (the instrument spectral line intensity meter reading μA)

[0063] f b is the slope of the regression line.

[0064] set up:

[0065] 0# water sample is high-purity blank water:

[0066] Assume that the sodium background concentration of high-purity blank water is x0 = C0 (μg / L);

[0067] The spectral line intensity value y0 of high-purity blank water is measured;

[0068] Then: y0=f bx0 (3)

[0069] Assume that water sample 1 is a high-purity blank water sample with sodium content x added S Standard solution:

[0070] Assume that the sodium concentration of water sample #1 is x1 (μg / L), and the spectral line intensity value y1 is measured;

[0071] Then: y1=f b x1 (4)

[0072] x1=x0+x S (The actual sodium concentration of water sample #1) (5)

[0073] Substituting equation (5) into equation (4), we can obtain:

[0074] f b =y1 / (x0+x s ) (6)

[0075] Substituting equation (6) into equation (3) yields the sodium background concentration of high-purity blank water:

[0076] x0(C0)=y0x s / (y1-y0) (7)

[0077] Substituting equation (7) into equation (6) yields the slope:

[0078] f b =(y1-y0) / x s (8)

[0079] Substitute (8) into the Lomakin-Scherbe formula (1):

[0080] The calculation formula for the true sodium concentration in the water sample is:

[0081] x=y / f b =x s y / (y1-y0) (9)

[0082] This embodiment automatically calculates the calibration results and automatically gives the sodium background concentration C0 [μg / L] value of the high-purity blank water and the regression line diagram of the calibration results (i.e., the Roman gold relationship curve). From the above derivation process, it can be seen that when using the "two-point calibration method" provided by this instrument to measure trace sodium, it is not required to have the "prerequisite" of "sodium-free water". As long as water with the same sodium content as the sample is used as "blank" water, the real trace sodium content in the water sample can be accurately measured.

[0083] The measuring module 304 is used to detect that the connection between the injection three-way valve 206 and the calibration switching solenoid valve 203 is in a closed state, the water sample inlet regulating solenoid valve 205 is in an open state, and the injection three-way valve 206 is connected to the injection water inlet pipe 207, and then control the injection-calibration component I to continuously and stably transport the water sample to be measured to the flame atomizer II, and obtain the measurement data of the water sample to be measured collected by the data acquisition component. Specifically, the measuring module 304 closes the water sample inlet regulating solenoid valve 205 according to the preset frequency, and opens the water sample inlet regulating solenoid valve 205 after collecting the measurement data. When the calibration module 303 completes the calibration process, it automatically enters the measurement process of the measuring module 304, that is, it starts to measure the real-time actual sodium concentration of the online water sample according to the instructions of the measurement program. At this time, the connection between the injection three-way valve 206 and the calibration switching solenoid valve 203 is in a closed state, the water sample inlet regulating solenoid valve 205 is in an open state, and the injection three-way valve 206 is connected to the injection water inlet pipe 207. The water sample from the water sample inlet regulating solenoid valve 205 of the boiler water and steam sampling rack flows continuously through the constant liquid level overflow water sample cup 208. The measurement frequency is preferably once / 10 minutes (a reading operation is performed every 10 minutes to complete a real-time water sample measurement). When the measurement data acquisition is triggered, the industrial computer instructs the single-chip microcomputer to close the water sample inlet regulating solenoid valve 205. After the data acquisition is completed, the water sample inlet regulating solenoid valve 205 is automatically opened immediately. In this way, the programmatic analysis operation of continuous sampling and intermittent static measurement is adopted. During the measurement process, the computer program closes the water sample inlet regulating solenoid valve 205 to realize the static measurement of the constant liquid level overflow water sample cup 208, ensuring the real-time representativeness of the measurement results, the stability of the measurement conditions, and the repeatability of the measurement results.

[0084] Data processing module 305: used to perform statistical analysis on the measurement data of the calibration water sample and the measurement data of the water sample to be measured in real time to obtain the trace sodium test results. Specifically, each measurement data output is the arithmetic mean of the statistical values ​​of 6 parallel measurement data at an interval of 1 second, and automatically gives statistical data such as the standard deviation of the measurement result, the relative standard deviation and the "uncertainty" of the measurement result. It can intelligently perform calibration and directly display the measurement results on the on-site LCD screen by determining the real-time actual sodium concentration of the water sample through the working curve of the coordinate origin. The calibrated measurement result is the true content value of sodium in the water sample.

[0085] The flame atomizer and trace sodium online monitoring system provided by the embodiment of the present invention, wherein the flame atomizer comprises an atomizer chamber, a first chamber, a second chamber and a third chamber which are connected in sequence. The atomizer chamber is provided with a sampling capillary, an oil-free compressed air inlet and an atomizer chamber outlet. When in use, the outer end of the sampling capillary can be inserted into the constant liquid level overflow water sample cup. At this time, the oil-free compressed air connected through the oil-free compressed air inlet forms a "negative pressure field" in the atomizer chamber, and the water sample to be measured in the constant liquid level overflow water sample cup (or high-level high-purity water for calibration, or high-level standard water sample for calibration) can be sucked into the atomizer chamber through the sampling capillary, so as to complete the atomization and preliminary mixing process of the water sample in the atomizer chamber and then sprayed out through the atomizer chamber outlet. The first chamber is provided with a gas inlet and an impact ball, and the impact ball is arranged opposite to the atomizer chamber outlet. The impact ball can smash the droplets sprayed from the atomizer chamber outlet, so that the aerosol mist particles are finer and more uniform. At the same time, the fuel gas connected through the gas inlet can be mixed with the aerosol sprayed from the outlet of the atomizer chamber in the first chamber and then enter the second chamber. The second chamber is provided with a high-temperature gas inlet, and the second chamber is filled with phase-change heat storage balls. The high-temperature gas enters through the high-temperature gas inlet and heats the phase-change heat storage balls. In this way, the "fog particles" of the aerosol sprayed from the atomizer chamber and crushed by the impact ball are fully in contact with the high-temperature phase-change heat storage balls, and the "fog particles" are heated and completely vaporized, and the atomization efficiency can reach 100%. A burner is arranged above the third chamber, and the burner is provided with a purified air inlet, and the annular center porous burner head of the burner is connected to the third chamber. The purified air (combustion-supporting gas) with stable pressure can be connected through the purified air inlet, so that the completely atomized temperature-stable high-temperature mixed gas coming out of the second chamber enters the third chamber, and can be ignited above the annular center porous burner head of the burner to form a flame, radiating a sodium characteristic spectrum of 589.0nm with stable spectral line intensity. It can be seen that the present technical solution can effectively solve the technical problems existing in the existing flame atomizers, such as low atomization rate, low flame temperature, unstable flame combustion, etc.

[0086] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. A flame atomizer, characterized in that: The flame atomizer includes an atomizer chamber, a first chamber, a second chamber and a third chamber which are connected in sequence; the atomizer chamber is provided with an injection capillary, an oil-free compressed air inlet and an atomizer chamber outlet, and the atomizer chamber outlet is connected with the atomizer chamber and the first chamber; the first chamber is provided with a fuel gas inlet and an impact ball, and the impact ball is arranged opposite to the atomizer chamber outlet; the second chamber is provided with a high-temperature gas inlet, and the second chamber is filled with phase change heat storage balls; a burner is provided above the third chamber, the burner is provided with a purified air inlet, and the annular central porous burner head of the burner is connected with the third chamber.

2. The flame atomizer according to claim 1, characterized in that A separation flange is provided between the first chamber and the second chamber, and between the second chamber and the third chamber, and the separation flange is provided with a through hole to respectively connect the first chamber and the second chamber, and the second chamber and the third chamber.

3. The flame atomizer according to claim 1, characterized in that The flame atomizer also includes an electrolytic high-purity water hydrogen generator, and the outlet of the electrolytic high-purity water hydrogen generator is connected to the fuel gas inlet.

4. The flame atomizer according to claim 1, characterized in that The flame atomizer also includes an oil-free air compressor, a precision air heater, a membrane dryer and an air filter purifier. A pressure regulating valve is arranged at the outlet of the oil-free air compressor. The outlet of the pressure regulating valve is connected to the inlet of the membrane dryer. The outlet of the membrane dryer is connected to the oil-free compressed air inlet via a first isolation valve. The outlet of the membrane dryer is connected to the inlet of the precision air heater via a second isolation valve. The outlet of the precision air heater is connected to the high-temperature gas inlet. The outlet of the membrane dryer is connected to the purified air inlet via the air filter purifier.

5. The flame atomizer according to claim 1, characterized in that The first chamber is also provided with a waste liquid discharge outlet, and one side of the third chamber is also provided with an explosion-proof membrane.

6. The flame atomizer according to claim 1, characterized in that A vacuum annular cavity is arranged inside the side wall of the second chamber to realize heat preservation treatment of the second chamber.

7. The flame atomizer according to any one of claims 1 to 6, characterized in that The phase-change heat storage ball includes a stainless steel spherical shell with a cavity, and a feeding sealing port is provided on the stainless steel spherical shell to fill the cavity of the stainless steel spherical shell with phase-change heat storage material.

8. The flame atomizer according to claim 7, characterized in that , the phase change temperature of the phase change thermal storage material is 400°C.

9. A trace sodium online monitoring system, characterized in that: The trace sodium online monitoring system comprises a sampling-calibration component, a second-order differential flame emission spectrometer and a flame atomizer as claimed in any one of claims 1 to 8, wherein: The sampling-calibration component is used to continuously and stably transport the calibration high-purity water, the standard water sample and the water sample to be measured to the atomizer chamber of the flame atomizer in sequence through the sampling capillary under the control of the second-order differential flame emission spectrometer; The flame atomizer is used to, under the control of the second-order differential flame emission spectrometer, sequentially atomize and flame atomize the calibration high-purity water, the standard water sample and the water sample to be measured delivered by the sampling-calibration component to form a flame radiating a 589.0nm sodium spectrum; The second-order differential flame emission spectrometer is used to control the operation of the sample injection-calibration component and the flame atomizer in real time, and to perform data analysis and processing on the flame formed by the flame atomizer in real time to obtain corresponding test results.

10. The trace sodium online monitoring system according to claim 9, characterized in that The injection-calibration component includes a high-position high-purity water cup for calibration, a high-position standard water sample cup for calibration, a calibration switching solenoid valve, a water inlet pipe for the water sample to be measured, a water sample inlet regulating solenoid valve, an injection three-way valve, a water sample inlet pipe and a constant liquid level overflow water sample cup. The water inlet pipe for the water sample to be measured is connected to the first inlet of the injection three-way valve via the water sample inlet regulating solenoid valve, the outlet of the high-position high-purity water cup for calibration and the outlet of the high-position standard water sample cup for calibration are respectively connected to the second inlet of the injection three-way valve via the calibration switching solenoid valve, one end of the water sample inlet pipe is connected to the outlet of the injection three-way valve, the other end of the water sample inlet pipe is inserted into the constant liquid level overflow water sample cup, the outer end of the injection capillary is inserted into the constant liquid level overflow water sample cup, and the outlet of the water sample inlet pipe is lower than the inlet of the injection capillary.

11. The trace sodium online monitoring system according to claim 10, characterized in that The sampling-calibration assembly also includes a fixed groove and an overflow water collecting cup, and the constant liquid level overflow water sample cup is installed in the overflow water collecting cup through the fixed groove.

12. The trace sodium online monitoring system according to claim 9, characterized in that , the second-order differential flame emission spectrometer comprises: The photoelectric sensor assembly is used to quickly scan the characteristic spectrum line of sodium and automatically deduct the background interference of the flame to generate a second-order differential modulated sodium spectrum, which is received and excited by the photomultiplier tube to generate a second-order differential frequency modulated current, and the second-order differential frequency modulated current is demodulated and amplified by the phase-locked amplifier and then output to the data acquisition assembly; A data acquisition component is used to collect the analog signal of the second-order differential frequency modulated current and convert it into a digital signal and output it to the embedded industrial computer component for real-time monitoring and control; The embedded industrial computer component is used to control the operation of the sampling-calibration component, the flame atomizer, the photoelectric sensor component and the data acquisition component in real time, and to perform statistical analysis and processing on the data collected by the data acquisition component in real time to obtain test results.

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