CN212255082U - Flame atomizer and trace sodium on-line monitoring system - Google Patents

Abstract

The utility model discloses a flame atomizer and trace sodium on-line monitoring system, belonging to the technical field of on-line analysis instruments, wherein the flame atomizer comprises an atomizer chamber, a first chamber, a second chamber and a third chamber which are sequentially communicated; the atomizer chamber is provided with a sample injection capillary tube, an oilless compressed air inlet and an atomizer chamber outlet, and the atomizer chamber outlet is communicated with the atomizer chamber and the first cavity; the first chamber is provided with a gas inlet and an impact ball, and the impact ball is arranged right opposite to the outlet of the atomizer chamber; the second chamber is provided with a high-temperature gas inlet and is filled with the phase-change heat storage balls; a burner is arranged above the third chamber, a purified air inlet is formed in the burner, and an annular central porous combustion head of the burner is communicated with the third chamber. The technical scheme can effectively solve the technical problems of low atomization rate, low flame temperature, unstable flame combustion and the like of the conventional flame atomizer.

Description

A flame atomizer and on-line monitoring system for trace sodium

technical field

The invention relates to the technical field of on-line analytical instruments, in particular to a flame atomizer and an on-line monitoring system for trace sodium.

Background technique

The flame atomizer is an important part of the spectrometer. It is a device that uses a flame to turn the ions in the test solution into atomic vapor. have a significant impact. The traditional flame atomizer consists of an atomizer, a premixing chamber and a burner. In the process of flame atomization, the liquid sample is atomized and brought into the flame for atomization by mixing oxidizing gas (air or oxygen) and gas (gas fuel), and the test liquid is introduced into the flame and atomized It has undergone a series of complex physical and chemical processes, including desolvation, evaporation, and dissociation of mist particles. During the dissociation process, most of the ions are dissociated into gaseous atoms.

At present, the second-order differential flame emission spectrometer follows the traditional flame atomizer. The burner uses normal temperature (ambient temperature) air to support 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 nebulizer. This nebulizer uses compressed air with a certain pressure as a combustor to enter the nebulizer. The incoming auxiliary gas scatters into mist droplets (aerosol). The more water samples are atomized, the finer the droplets are, the easier it is to dry, melt, and vaporize, and the more free atoms are generated, the higher the sensitivity of the spectrometer. However, the atomization efficiency of this traditional atomizer can only reach about 10% at the highest. 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 an oxygen-rich-acetylene flame, and the utility model: ZL 201620667866.2 uses a hydrogen-oxygen flame to increase the flame temperature. However, due to the high combustion speed of the oxygen-enriched-acetylene flame and the hydrogen-oxygen flame during the use of the above measures, it is easy to cause a flashback and explosion accident, which threatens the safety of the user and the use of the instrument.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to propose a flame atomizer and a trace sodium online monitoring system, which aims to solve the problems of the existing flame atomizers such as low atomization efficiency, low flame temperature, and unstable flame combustion. question.

In order to achieve the above object, the present invention provides a flame atomizer, the flame atomizer comprises an atomizer chamber, a first chamber, a second chamber and a third chamber which are connected in sequence; The nebulizer chamber is provided with a sampling capillary, an oil-free compressed air inlet and an outlet of the nebulizer chamber, and the outlet of the nebulizer chamber communicates with the nebulizer chamber and the first chamber; the first chamber is provided with There are a gas inlet and an impact ball, and the impact ball is arranged facing the outlet of the atomizer chamber; 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 arranged above the third chamber, the burner is provided with a clean air inlet, and the annular central porous combustion head of the burner communicates with the third chamber.

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 is used to communicate with the first chamber and the second chamber, and the second chamber and the third chamber respectively.

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 gas inlet.

Optionally, the flame atomizer also includes an oil-free air compressor, a precision air heater, a membrane dryer and an air filter purifier, and a pressure regulating valve is provided at the outlet of the oil-free air compressor, and the 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 through the first isolation valve, and the outlet of the membrane dryer is isolated through the second The valve is connected to the inlet of the precision air heater, the outlet of the precision air heater communicates with the high temperature gas inlet, and the outlet of the membrane dryer communicates with the purified air inlet through the air filter purifier.

Optionally, the first chamber is further provided with a waste liquid discharge port, and one side of the third chamber is further provided with an explosion-proof membrane.

Optionally, a vacuum annular cavity is arranged in the side wall of the second chamber, so as to realize the heat preservation treatment of the second chamber.

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 phase change heat storage in the cavity of the stainless steel spherical shell. Material.

Optionally, the phase change temperature of the phase change heat storage material is 400°C.

In addition, in order to achieve the above object, the present invention also provides a trace sodium online monitoring system, the trace sodium online monitoring system comprises a sample injection-calibration assembly, a second-order differential flame emission spectrometer and the above-mentioned flame atomizer, Wherein, the sample injection-calibration assembly is used to continuously and stably transport the high-purity water for calibration, the standard water sample and the water sample to be measured through the sample injection capillary to the The atomizer chamber of the flame atomizer; the flame atomizer is used to sequentially carry out the sample injection-calibration assembly under the control of the second-order differential flame emission spectrometer. High-purity water for calibration, the standard water sample and the water sample to be measured are atomized and flame atomized to form a flame that radiates 589.0 nm sodium spectrum; the second-order differential flame emission spectrometer is used to control the process in real time. The sample-calibration component and the operation of the flame atomizer are analyzed and processed in real time on the flame formed by the flame atomizer to obtain corresponding test results.

Optionally, the sample injection-calibration assembly includes a high-level high-purity water cup for calibration, a high-level standard water sample cup for calibration, a calibration switching solenoid valve, a water sample inlet pipe to be measured, a water sample inlet adjustment solenoid valve, and a sample injection three-way valve. , a water sample inlet pipe and a constant liquid level overflow water sample cup. The water sample inlet pipe to be measured is connected to the first inlet of the sample injection three-way valve through the water sample inlet adjustment solenoid valve. The outlet of the high-purity water cup and the outlet of the high-level standard water sample cup for calibration are respectively connected to the second inlet of the sampling three-way valve through the calibration switching solenoid valve, and one end of the water sample inlet pipe is connected to the The outlet of the sample 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 sample injection capillary is inserted into the constant liquid level overflow water sample cup, and The outlet of the water sample inlet tube is lower than the inlet of the sample inlet capillary.

Optionally, the sample injection-calibration assembly further includes a fixed groove and an overflow water collection cup, and the constant liquid level overflow water sample cup is installed in the overflow water collection cup through the fixed groove.

Optionally, the second-order differential flame emission spectrometer includes: a photoelectric sensor assembly for rapidly scanning the characteristic spectral lines of sodium and automatically deducting and removing the background interference of the flame to generate a second-order differentially modulated sodium spectrum to be multiplied by photoelectricity. The second-order differential FM current is received and excited by the tube, and the second-order differential FM current is demodulated and amplified by the lock-in amplifier and then output to the data acquisition component; the data acquisition component is used to collect the analog signal of the second-order differential FM 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 sample injection-calibration component, the flame atomizer, the photoelectric sensor component and the The data collection component operates, and the data collected by the data collection component is statistically analyzed and processed in real time to obtain a test result.

In the flame atomizer and the trace sodium online monitoring system provided by the present invention, the flame atomizer comprises an atomizer chamber, a first chamber, a second chamber and a third chamber which are connected in sequence. The nebulizer chamber is provided with a sampling capillary, an oil-free compressed air inlet and an outlet of the nebulizer chamber. When in use, the outer end of the sampling capillary can be inserted into the constant liquid level overflow water sample cup. The oil-free compressed air connected to the air inlet forms a "negative pressure field" in the nebulizer chamber, which can make 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) It is sucked into the nebulizer chamber through the sample injection capillary, and sprayed through the outlet of the nebulizer chamber after the atomization and preliminary mixing process of the water sample is completed in the nebulizer chamber. The first chamber is provided with a gas inlet and an impact ball, and the impact ball is arranged directly at the outlet of the atomizer chamber. The impact ball can smash the droplets ejected from the outlet of the atomizer chamber, so that the aerosol mist particles are finer. , more uniform. At the same time, the fuel gas connected through the gas inlet can enter the second chamber after mixing with the aerosol sprayed from the outlet of the atomizer chamber in the first chamber. The second chamber is provided with a high-temperature gas inlet, and the second chamber is filled with phase-change heat storage balls, and the high-temperature gas enters through the high-temperature gas inlet and heats the phase-change heat storage balls. The "fog particles" of the aerosol crushed by the impact ball fully contact with the high-temperature phase change heat storage ball, 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 central porous combustion head of the burner is connected to the third chamber, through which the purified air with stable pressure (assistant gas) can be connected , so that the completely atomized temperature-stable high-temperature mixed gas from the second chamber enters the third chamber, and can be ignited above the annular center porous combustion head of the burner to form a flame, radiating a stable spectral line intensity of 589.0nm. characteristic spectrum of sodium. It can be seen that this technical solution can effectively solve the technical problems of the existing flame atomizer, such as low atomization rate, low flame temperature, and unstable flame combustion.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

FIG. 1 is an overall structural diagram of a phase-change regenerative constant temperature flame atomizer provided in Embodiment 1 of the present invention.

FIG. 2 is a schematic structural diagram of the phase-change heat storage ball of the flame atomizer shown in FIG. 1 .

Fig. 3 is the structural block diagram of the trace sodium online monitoring system provided in the second embodiment of the present invention.

FIG. 4 is a schematic structural diagram of the sample injection-calibration component of the trace sodium online monitoring system shown in FIG. 3 .

FIG. 5 is a structural block diagram of the embedded industrial computer of the second-order differential flame emission spectrometer of the trace sodium online monitoring system shown in FIG. 3 .

Fig. 6 is a flow chart of the specific calibration process of the calibration module of the embedded industrial computer shown in Fig. 5

Fig. 7 is the Roman gold relation curve of the principle of atomic emission spectroscopy.

Detailed ways

The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted here that the descriptions of these embodiments are used to help the understanding of the present invention, but do 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.

Example 1

As shown in FIG. 1 , the first embodiment of the present invention provides a flame atomizer II. The flame atomizer II includes an atomizer chamber 110 , a first chamber 120 , a second chamber 130 and an atomizer chamber 110 , a first chamber 120 , a second chamber 130 and The third chamber 140 . The nebulizer chamber 110 is provided with a sampling capillary 111 , an oil-free compressed air inlet 112 and an outlet 113 of the nebulizer chamber. The outlet 113 of the nebulizer chamber communicates with the nebulizer chamber 110 and 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 disposed facing the outlet 113 of the atomizer chamber. The second chamber 130 is provided with a high temperature gas inlet 131 , and the second chamber 130 is filled with phase change heat storage balls 132 . A burner 141 is provided above the third chamber 140 , the burner 141 is provided with a clean air inlet 142 , and the annular central porous combustion head of the burner 141 communicates with the third chamber 140 .

In this embodiment, as shown in FIG. 1 , 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 method The flange 10 is provided with a through hole 11 to communicate with the first chamber 120 and the second chamber 130 and the second chamber 130 and the third chamber 140 respectively. In this way, the first chamber 120 , the second chamber 130 , and the third chamber 140 can be separated to form the first chamber 120 , the second chamber 130 , and the third chamber 140 through the partition flange 10 with the through hole 11 , and the three chambers can be partially communicated in turn.

As shown in FIG. 2 , the phase change heat storage ball 132 includes a stainless steel spherical shell 1321 with a cavity. The stainless steel spherical shell 1321 is provided with a feeding sealing port 1322, so that the cavity of the stainless steel spherical shell 1321 is filled with the phase change accumulator. Thermal material 1323. Specifically, the stainless steel spherical shell 1321 is a stainless steel hollow ball with a diameter of 8mm-16mm, the feeding sealing port 1322 is filled with a stainless steel plug coated with high temperature resistant glue to seal the outer hole, and the volume of the phase change heat storage material 1323 is the volume of the stainless steel spherical shell 2/3-3/4, the phase change thermal storage material 1323 is a solid-solid composite phase change material, and the phase transition temperature of this solid-solid composite phase change thermal storage material is designed to be 400°C. The second chamber 130 is a “phase-change heat-storage atomizing bed” filled with phase-change heat-storage balls 132 , and the aerosol mist and high-temperature phase are ejected from the atomizer chamber 110 and smashed by the impact balls 122 . The variable heat storage ball 132 is fully contacted and atomized completely, and the atomization efficiency can reach 100%.

As shown in FIG. 1 , the flame atomizer II in this embodiment further 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 . The outlet of the electrolytic high-purity water hydrogen generator 150 is connected to the gas inlet 121, and high-purity hydrogen is connected to the gas inlet 121 as fuel gas, which can further ensure the combustion stability of the burner. A pressure regulating valve 12 is provided at the outlet of the oil-free air compressor 160 , the outlet of the pressure regulating valve 12 is connected to the inlet of the membrane dryer 180 , and the outlet of the membrane dryer 180 is connected to the oil-free compressed air inlet through the first isolation valve 13 112, 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 air filter purifier 190 communicates with the clean air inlet 142 . That is, the “purified air” connected to the purified air inlet 142 in this embodiment is the dry air output from the outlet of the membrane dryer 180 to be further removed by the air filter purifier 190 (specifically, a 0.1 μ precision filter). Clean air obtained after solid and liquid particles in the air. This "purified air" enters the annular channel of the annular center porous combustion 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 mixture in the third chamber 140, it will A slightly positive pressure annular protective cover is formed around the flame torch that radiates the sodium emission spectrum formed above the burner 141. This annular protective cover has the function of automatically diffusing to the periphery of the flame, which can effectively prevent various Trace interfering components (salt mist and dust particles) enter the center of the atomized flame, enabling trace analysis and stable measurement results under normal measurement ambient conditions.

In addition, as shown in FIG. 1 , the first chamber 120 is further provided with a waste liquid discharge port 123 to discharge waste liquid. One side of the third chamber 140 is also provided with an explosion-proof membrane 143 to ensure the safety performance of the third chamber 140 when the burner 142 is working. A vacuum annular cavity 133 is disposed in the side wall of the second chamber 130 to realize the heat preservation treatment of the second chamber 130 .

During operation, the oil-free compressed air with stable pressure output by the oil-free air compressor 160 after being adjusted by the pressure regulating valve 12 enters the atomizer chamber 110 through the oil-free compressed air inlet 112, and forms a """ in the atomizer chamber 110. Negative pressure field” to inhale the water sample to be measured (or high-level high-purity water for calibration, or high-level standard water sample for calibration) through the sampling capillary 111, and complete the atomization and preliminary mixing process of the water sample in the atomizer chamber 110 , and then ejected from the outlet 113 of the atomizer chamber. At this time, the impact ball 122 in the first chamber 120 can smash the droplets ejected from the outlet 113 of the atomizer chamber, so that the aerosol mist particles are finer. , more uniform. At the same time, the high-purity hydrogen output from the electrolytic high-purity water hydrogen generator 150 enters the first chamber 120 from the gas inlet 121 to mix with the aerosol sprayed from the atomizer chamber 110 and enter the second chamber 130 . Since the second chamber 130 is a "phase-change heat-storage atomizing bed" filled with the phase-change heat-storage balls 132, the "mist particles" of the aerosol sprayed from the atomizer chamber 110 and struck and crushed by the impact balls 122 In full contact with the high temperature phase change heat storage ball 130, the "fog particles" are heated and completely vaporized, and the atomization efficiency can reach 100%. Finally, the fully atomized and stable high-temperature mixed gas from the second chamber 130 enters the third chamber 140, and is ignited above the annular central porous combustion head of the burner 141 to form a flame, radiating a stable spectral line intensity. Sodium characteristic spectrum at 589.0 nm.

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 to make the outlet pressure of the oil-free air compressor 160 be 0.25MP, close the first The first isolation valve 13 opens the second isolation valve 14 to heat the compressed air through the precision air heater 170, and controls the outlet temperature of the precision air heater 170 to be 400±5°C; (2) The high temperature air enters the phase change accumulator through the high temperature gas inlet 131 In the thermal atomizing bed (ie the second chamber 130), the high temperature air contacts the phase change heat storage ball 132 and heats the phase change heat storage ball 132; until the temperature of the hot air at the outlet of the burner 141 is stabilized at the phase change temperature +5°C (3 ) Close the second isolation valve 14 and open the first isolation valve 13 to enter the oxidant gas into the atomizer chamber 110 through the oxidant gas inlet (ie, the oil-free compressed air inlet 112 ) to form a “negative pressure field” in the atomizer chamber 110 The water sample to be measured enters the nebulizer chamber 110 through the sampling capillary 111 and is atomized into fine droplets and enters into the phase-change thermal storage atomizing bed (ie, the second chamber 130 ) to contact with the constant-temperature phase-change thermal storage ball 132 The atomized, hot constant temperature and high temperature mixed gas is ignited above the outlet of the burner 141 to form a high temperature flame with stable temperature and radiate the characteristic emission spectrum of Na element at 589.0 nm.

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%. The sensitivity of trace sodium analysis is improved by an order of magnitude over second-order differential flame emission spectrometers using conventional concentric nebulizers. (2) The use of the phase change regenerative atomizing bed realizes the high temperature preheating of the auxiliary gas, increases the atomization temperature, and improves the sensitivity and detection limit of the analysis. (3) The use of the phase change regenerative atomizing bed realizes the constant temperature and high temperature of the premixed gas, which makes the temperature of the atomization flame stable and improves the repeatability of the measurement results. (4) The detection limit of trace sodium in high-purity water by second-order differential flame emission spectrometry has reached an advanced level of less than 0.1 μg/L. (5) Compared with graphite furnace atomic absorption spectrometer and inductively coupled plasma emission spectrometer (ICP), it has obvious advantages of simple equipment, simple operation and low analysis cost.

Embodiment 2

As shown in FIG. 3 , the second embodiment of the present invention provides an online monitoring system for trace sodium, which includes a sample injection-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 high-purity water for calibration, the standard water sample and the water sample to be measured through the sampling capillary 111 to the flame atomization under the control of the second-order differential flame emission spectrometer III. The atomizer chamber 110 of the device II. The flame atomizer II is mainly used to atomize and flame atomize the high-purity water for calibration, the standard water sample and the water sample to be measured from the sample injection-calibration component I in turn under the control of the second-order differential flame emission spectrometer III. chemical treatment, forming a flame emitting a sodium spectrum of 589.0 nm. The second-order differential flame emission spectrometer III is mainly used to control the operation of the sample injection-calibration component I and the flame atomizer II in real time, and to analyze and process the flame formed by the flame atomizer II in real time, and obtain the corresponding test results.

In this embodiment, as shown in FIG. 4 , the sample injection-calibration assembly 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 The sample inlet adjustment solenoid valve 205, the sample injection three-way valve 206, the water sample inlet pipe 207 and the constant liquid level overflow water sample cup 208, the water sample inlet pipe 204 to be measured is connected to the sample injection tee through the water sample inlet adjustment solenoid valve 205 The first inlet of the valve 206, the outlet of the high-level high-purity water cup 201 for calibration and the outlet of the high-level standard water sample cup 202 for calibration are respectively connected to the second inlet of the sampling three-way valve 206 through the calibration switching solenoid valve 203, and the water sample water inlet pipe One end of the 207 is connected to the outlet of the sampling 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, and the outer end of the sampling 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 sample inlet capillary 111 . During work, the high-level high-purity water cup 201 for calibration is filled with high-level high-purity water for calibration, and the high-level standard water sample cup 202 for calibration is filled with standard water samples (ie, 10 μg/L sodium standard water sample), and the water sample inlet pipe 204 to be measured is connected to Water sample to be measured. By switching the calibration switching solenoid valve 203 , the water sample inlet regulating solenoid valve 205 and the sampling three-way valve 206 respectively, the high-purity water for calibration, the standard water sample and the water sample to be measured can be sequentially passed through the water sample inlet pipe 207 and the constant liquid level. The overflow water sample cup 208 and the sample injection capillary 111 are continuously and stably transported into the atomizer chamber 110 of the flame atomizer II.

Specifically, as shown in FIG. 4 , the sample injection-calibration assembly I further 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 a high-level high-purity water cup 201 for calibration, a high-level standard water sample cup 202 for calibration, and a three-way injection valve 206 . The other two paths of the sampling three-way valve 206 communicated with the calibration switching solenoid valve 203 are respectively communicated with the water sample inlet regulating solenoid valve 205 and the water sample inlet pipe 207 . Among them, the high-level high-purity water cup 201 for calibration and the high-level standard water sample cup 202 for calibration can be an open-bottom polyethylene (PE) container with a capacity of 1000mL, the bottom of the container is a conical funnel structure, and the bottom of the container is connected to the sample injection The height difference of the inlet of the capillary 111 is the second preset height difference (preferably about 1000 mm). The high-purity water for calibration refers to the high-purity water used to prepare the standard water sample for the current calibration. The outlet of the water sample water inlet pipe 207 is lower than the inlet of the sample injection capillary 111 by a first preset height difference (preferably about 10 mm), and the sample injection capillary 111 is connected to the flame atomizer from the bottom of the constant liquid level overflow water sample cup 208 inside the nebulizer chamber 110. The constant liquid level overflow water sample cup 208 is preferably a 125mL standard PE narrow-mouth sampling bottle placed in the 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), the flow rate of the water sample 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 port of the 125mL standard PE narrow-mouth sampling bottle. The function of the overflow of the constant liquid level overflow water sample cup 208 is to keep the water at the inlet of the sampling capillary 111 during the measurement process. The liquid column height of the sample is stable. This stable water sample height can stabilize the static pressure at the inlet of the sampling capillary 111. Keeping the static pressure at the inlet of the sampling capillary 111 stable, the pressure of the carrier gas (hydrogen-oxygen mixture) can be stable. Under the conditions, the lifting amount of the water sample entering the nebulizer is guaranteed to be stable. The stability of the lifting amount of the water sample 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 sampling capillary 111 by the first preset height difference (about 10 mm), which can ensure the real-time performance of the water sample entering the sampling capillary 111, thereby ensuring the real-time representation of the measurement data. sex.

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 spectral lines of sodium and automatically deduct the background interference of the flame to generate a second-order differential modulation sodium spectrum, which is received and excited by the photomultiplier tube to generate a second-order differential frequency modulation current. The second-order differential FM current is demodulated and amplified by the lock-in 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 modulation 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 sample injection-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. Test Results.

The embedded industrial computer components specifically include an embedded industrial computer (host) and a resistive touch screen (display). The embedded industrial computer can be responsible for processing and displaying the digital signals transmitted from the lower computer. USB is used between the host and the slave. to communicate. In this way, the user can write various functional programs on the host computer to effectively query and analyze the data in the file, which is beneficial to the long-term normal operation and inspection of the analysis and measurement process. As shown in FIG. 5 , 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 .

System setting module 301: used to set the characteristic spectral line wavelength of the automatic scanning second-order differential precision grating monochromator to 589.0 nm; 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 is less than ±0.03%/h and the negative high voltage DC voltage value. In terms of operation, after the user turns on the power of the host, the power of the monochromator, the power of the silicon nitride ignition and the power of the computer, use the USB connection cable to connect the industrial computer and the lower computer (host), the computer and the monochromator. Start the icon of the trace sodium online monitoring software, and complete the system setting steps in the software man-machine interface dialog box. The parameters of the system setting include but are not limited to the system time setting, the characteristic spectral line wavelength setting 589.0nm, the negative value of the photomultiplier tube. High pressure setting, user name setting. After completing the setting, the computer will perform system testing, and the testing parameters include but are not limited to: output pressure of 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, the status signal of the calibration switching solenoid valve, the status signal of the injection three-way valve, the status signal of the water sample inlet adjustment solenoid valve, etc.

Ignition module 302: used to turn on the electrolytic high-purity water hydrogen generator 150, and activate 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.

Calibration module 303: After detecting that the status signal of the flame sensor is normal, control the sample injection-calibration component I to continuously and stably transport the high-purity water for calibration and the standard water sample for calibration to the flame atomizer II, and send it to the data acquisition component. The data acquisition command obtains the measurement data of the calibration water sample collected by the data acquisition component. specifically,

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

S110, close the water sample inlet adjustment solenoid valve 205.

S120 , open the calibration switching solenoid valve 203 and tangentially calibrate the high-level high-purity water cup 201 .

S130 , open the sample injection three-way valve 206 , so that the high-purity water flows into the constant liquid level overflow water sample cup 208 .

Specifically, after opening the sampling three-way valve 206, the high-purity water flows into the constant-level overflow water sample cup 208 through the sampling water inlet pipe 207, and the high-purity water from the high-level high-purity water cup 201 for calibration is automatically sucked into the nebulizer chamber 110 through the sampling capillary 111. The process of atomization, mixing, and droplet separation is completed in the middle, and then a flame that radiates 589.0 nm sodium spectrum is ignited above the outlet of the annular center porous combustion head of the burner 141 .

S140. Send a data collection instruction to the data collection component, and obtain the measurement result of the high-purity water collected by the data collection component.

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

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

Specifically, after the high-purity water injection reading is completed, the calibration switching solenoid valve 203 is tangentially calibrated with the high-level standard water sample cup 202, and the 10 μg/L sodium standard water sample flows into the constant liquid level overflow water sample cup 208, and starts after rinsing for 3 minutes. Collect data, complete the data collection of 10 μg/L sodium standard water sample.

S160, close the calibration switching solenoid valve 203, and open the water sample inlet adjusting solenoid valve 205.

S170, obtaining the calibration regression line and the sodium background concentration of the high-purity blank water.

Specifically, the sodium ions in the water sample are atomized in a high-temperature flame and excited to emit a "characteristic spectral line" of sodium atoms. Under the condition of extremely low sodium ion concentration (trace amount), the intensity of its spectral line is different from that of the test. The concentration of sodium ions in the sample is proportional to the Roman gold formula (as shown in Figure 7).

Among them, the physical meaning of the Roman gold formula is: the calibration curve of the atomic emission spectrum must be a straight line passing through the origin (if and only when the sodium ion concentration in the water sample is zero, the measured value of the spectral line intensity can be zero), This provides a theoretical basis for the measurement and calibration of atomic emission spectroscopy without the need to prepare "sodium-free water". In fact, under the existing technical conditions, the real "sodium-free water" does not exist in the laboratory. The recognition and use of "sodium-free water" is a prerequisite for the measurement of trace amounts of sodium by atomic absorption and liquid chromatography.

which is:

y=f _b x (1)

x=y/f _b (2)

In the formula: x is the true concentration of sodium in the water sample (μg/L);

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

f _b is the slope of the regression line.

Assume:

0# water sample is high-purity blank water:

Let the sodium background concentration of high-purity blank water x ₀ =C ₀ (μg/L);

Measure the spectral line intensity value y ₀ of high-purity blank water;

Then: y ₀ =f _b x ₀ (3)

Let the 1# water sample be the standard solution with sodium content x _S added to the high-purity blank water sample:

Let the sodium concentration of the 1# water sample be x ₁ (μg/L), and measure the spectral line intensity value y ₁ ;

Then: y ₁ =f _b x ₁ (4)

x ₁ = x ₀ +x _S (true sodium concentration of water sample #1) (5)

Substitute equation (5) into equation (4) to solve:

f _b =y ₁ /(x ₀ +x _s ) (6)

Substitute equation (6) into equation (3) to obtain the sodium background concentration of high-purity blank water:

x ₀ (C ₀ )=y ₀ x _s /(y ₁ -y ₀ ) (7)

Substitute equation (7) into equation (6) to get the slope:

f _b =(y ₁ -y ₀ )/x _s (8)

Substitute equation (8) into Lomakin-Scherbe equation (1)

Obtain the formula for calculating the true sodium concentration in the water sample:

x=y/f _b =x _s y/(y ₁ -y ₀ ) (9)

This embodiment automatically calculates the calibration results, and automatically provides the regression line graph (ie, the Roman gold relationship curve) between the sodium background concentration C ₀ [μg/L] value of high-purity blank water and the calibration results. It can be seen from the above derivation process: when using the "two-point calibration method" provided by this instrument to measure trace sodium, it is not required to have the "premise" of "sodium-free water", as long as the water with the same level of sodium content as the sample is used as the "premise""Blank" water can accurately determine the true trace sodium content in the water sample.

Measurement module 304: used to detect that the connection between the sampling three-way valve 206 and the calibration switching solenoid valve 203 has been closed, the water sample inlet regulating solenoid valve 205 has been opened, and the sampling three-way valve 206 has been connected to the sampling After the water inlet pipe 207, the sample injection-calibration component I is controlled to continuously and stably transport the water sample to be measured to the flame atomizer II, and the measurement data of the water sample to be measured collected by the data acquisition component is acquired. Specifically, the measurement 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 transfers to the measurement process of the measurement module 304, that is, starts to measure the real-time actual sodium concentration of the online water sample according to the instruction of the measurement program. At this time, the connection between the sampling three-way valve 206 and the calibration switching solenoid valve 203 has been closed, the water sample inlet regulating solenoid valve 205 has been opened, and the sampling three-way valve 206 has been connected to the sampling water inlet pipe 207 . The water sample from the water sample inlet regulating solenoid valve 205 of the boiler water and steam sampling rack continuously flows through the constant liquid level overflow water sample cup 208 . The measurement frequency is preferably 1 time/10min, (a reading operation is performed every 10 minutes to complete a real-time water sample measurement) when triggering measurement data acquisition, the industrial computer instructs the single-chip microcomputer to close the water sample inlet adjustment solenoid valve 205. Immediately after completing the data collection, the water sample inlet regulating solenoid valve 205 is automatically opened. In this way, continuous sample injection, the programmed analysis operation of intermittent static measurement is adopted, and the computer program in the measurement process closes the water sample inlet and adjusts the solenoid valve 205 to realize the static measurement of the overflow water sample cup 208 with constant liquid level, so as to ensure the real-time representativeness of the measurement results and ensure the The stability of the measurement conditions ensures the repeatability of the measurement results.

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, and obtain the trace sodium test result. Specifically, each output measurement data is the arithmetic mean of the statistical values of 6 parallel measurement data with an interval of 1 second, and automatically gives the standard deviation, relative standard deviation and "uncertainty" of the measurement results. and other statistics. It can intelligently calibrate and directly display the measurement result on the 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 of sodium in the water sample.

In the flame atomizer and the trace sodium online monitoring system provided by the embodiment of the present invention, the flame atomizer includes an atomizer chamber, a first chamber, a second chamber and a third chamber which are connected in sequence. The nebulizer chamber is provided with a sampling capillary, an oil-free compressed air inlet and an outlet of the nebulizer chamber. When in use, the outer end of the sampling capillary can be inserted into the constant liquid level overflow water sample cup. The oil-free compressed air connected to the air inlet forms a "negative pressure field" in the nebulizer chamber, which can make 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) It is sucked into the nebulizer chamber through the sample injection capillary, and sprayed through the outlet of the nebulizer chamber after the atomization and preliminary mixing process of the water sample is completed in the nebulizer chamber. The first chamber is provided with a gas inlet and an impact ball, and the impact ball is arranged directly at the outlet of the atomizer chamber. The impact ball can smash the droplets ejected from the outlet of the atomizer chamber, so that the aerosol mist particles are finer. , more uniform. At the same time, the fuel gas connected through the gas inlet can enter the second chamber after mixing with the aerosol sprayed from the outlet of the atomizer chamber in the first chamber. The second chamber is provided with a high-temperature gas inlet, and the second chamber is filled with phase-change heat storage balls, and the high-temperature gas enters through the high-temperature gas inlet and heats the phase-change heat storage balls. The "fog particles" of the aerosol crushed by the impact ball fully contact with the high-temperature phase change heat storage ball, 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 central porous combustion head of the burner is connected to the third chamber, through which the purified air with stable pressure (assistant gas) can be connected , so that the completely atomized temperature-stable high-temperature mixed gas from the second chamber enters the third chamber, and can be ignited above the annular center porous combustion head of the burner to form a flame, radiating a stable spectral line intensity of 589.0nm. characteristic spectrum of sodium. It can be seen that this technical solution can effectively solve the technical problems of the existing flame atomizer, such as low atomization rate, low flame temperature, and unstable flame combustion.

The embodiments of the present invention have been 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, without departing from the principle and spirit of the present invention, various changes, modifications, substitutions and alterations to these embodiments still fall within the protection scope of the present invention.

Claims (12)

1. The flame atomizer is characterized by comprising an atomizer chamber, a first chamber, a second chamber and a third chamber which are sequentially communicated; the atomizer chamber is provided with a sample injection capillary tube, an oil-free compressed air inlet and an atomizer chamber outlet, and the atomizer chamber outlet is communicated with the atomizer chamber and the first cavity; the first chamber is provided with a gas inlet and an impact ball, and the impact ball is arranged right opposite to the atomizer chamber outlet; the second chamber is provided with a high-temperature gas inlet and is filled with phase-change heat storage balls; the top of third chamber is provided with the combustor, the combustor is provided with the air-purifying entry, just the porous burning head intercommunication in annular center of combustor the third chamber.

2. The flame atomizer according to claim 1, wherein 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 communicate the first chamber with the second chamber, and the second chamber with the third chamber, respectively.

3. The flame atomizer according to claim 1, further comprising an electrolytic high purity water hydrogen generator, an outlet of said electrolytic high purity water hydrogen generator being in communication with said fuel gas inlet.

4. The flame atomizer according to claim 1, further comprising an oil-free air compressor, a precision air heater, a membrane dryer, and an air filtration purifier, wherein a pressure regulating valve is disposed at an outlet of the oil-free air compressor, an outlet of the pressure regulating valve is connected to an inlet of the membrane dryer, an outlet of the membrane dryer is communicated with the oil-free compressed air inlet via a first isolation valve, an outlet of the membrane dryer is connected to an inlet of the precision air heater via a second isolation valve, an outlet of the precision air heater is communicated with the high-temperature gas inlet, and an outlet of the membrane dryer is communicated with the purified air inlet via the air filtration purifier.

5. The flame atomizer according to claim 1, wherein said first chamber is further provided with a waste liquid discharge port, and one side of said third chamber is further provided with an explosion-proof membrane.

6. The flame atomizer according to claim 1, wherein a vacuum annular cavity is provided in the sidewall of said second chamber to effect a heat-insulating treatment of said second chamber.

7. A flame atomizer according to any one of claims 1-6, characterized in that said phase change heat storage ball comprises a stainless steel ball shell with a cavity, and a charging seal is arranged on said stainless steel ball shell to fill the cavity of said stainless steel ball shell with phase change heat storage material.

8. The flame atomizer according to claim 7, characterized in that the phase change temperature of said phase change heat storage material is 400 ℃.

9. An online trace sodium monitoring system, which comprises a sample introduction-calibration component, a second order differential flame emission spectrometer and a flame atomizer according to any one of claims 1 to 8,

the sample introduction-calibration assembly is used for sequentially and continuously and stably conveying high-purity water for calibration, a standard water sample and a water sample to be measured to the atomizer chamber of the flame atomizer through the sample introduction capillary under the control of the second-order differential flame emission spectrometer;

the flame atomizer is used for sequentially atomizing and flame-atomizing the high-purity calibration water, the standard water sample and the water sample to be measured which are conveyed by the sample introduction-calibration assembly under the control of the second-order differential flame emission spectrometer to form flame with 589.0nm sodium spectrum radiation;

the second-order differential flame emission spectrometer is used for controlling the operation of the sample introduction-calibration assembly and the flame atomizer in real time, and analyzing and processing data of flame formed by the flame atomizer in real time to obtain a corresponding test result.

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

11. The online trace sodium monitoring system according to claim 10, wherein the sample injection-calibration assembly further comprises a fixing groove and an overflow water collecting cup, and the constant liquid level overflow water sample cup is mounted in the overflow water collecting cup through the fixing groove.

12. The online trace sodium monitoring system according to claim 9, wherein the second order differential flame emission spectrometer comprises:

the photoelectric sensor assembly is used for rapidly scanning the characteristic spectral line of sodium and automatically deducting background interference of flame to generate a second-order differential modulation sodium spectrum so as to be received and excited by a photomultiplier to generate second-order differential frequency modulation current, and the second-order differential frequency modulation current is demodulated and amplified by a phase-locked amplifier and then is output to the data acquisition assembly;

the data acquisition assembly is used for acquiring an analog signal of the second-order differential frequency modulation current, converting the analog signal into a digital signal and outputting the digital signal to the embedded industrial personal computer assembly for real-time monitoring and control;

and the embedded industrial personal computer component is used for controlling the operation of the sample introduction-calibration component, the flame atomizer, the photoelectric sensor component and the data acquisition component in real time, and carrying out statistical analysis and processing on data acquired by the data acquisition component in real time to obtain a test result.

Images