Self-adding sodium ammonia ion analyzer

Abstract

This self-addition sodium ion analyzer belongs to the technical field of trace sodium ion detection. The analyzer includes a sample alkalization cup, an alkalization system, a measuring flow cell, a sodium ion electrode, a pH triple-electrode, and an instrument display and control unit. The sample alkalization cup employs a variable flow path structure, utilizing the Venturi effect to raise the pH of the water sample to above 11 without the need for an external power source such as a pump. An additional sample buffer cell controls the sample flow rate, reduces electrode response time, and eliminates interference from small air bubbles. The sensor sequence is adjusted, with the sodium electrode preceding the pH electrode. A pH triple-electrode is added to measure the pH and temperature of the alkalized water sample and serves as a reference electrode for the sodium electrode. A sample evacuation function is also included to prevent cross-contamination between different samples. The analyzer features dynamic measurement capabilities, exhibiting excellent repeatability and high accuracy when measuring low sodium levels. It also possesses precise pH measurement capabilities, ensuring measurement reliability.

Description

Technical Field

[0001] This invention relates to a self-addition sodium ion analyzer, belonging to the technical field of trace sodium ion detection. Background Technology

[0002] In the analysis of sodium ions, especially trace sodium ions, pH ≥ pNa+3 is usually required. In practice, it is often adjusted to 10~10.5 or higher. The core purpose is to eliminate the interference of hydrogen ions (H⁺) on the pNa glass electrode. This is because in the detection of trace sodium ions, the signal of Na⁺ itself is very weak, and the interference signal of H⁺ will be amplified, directly leading to detection failure.

[0003] Currently, static measurement is mainly used to increase the pH of samples: either by manual addition of diisopropylamine by laboratory technicians or by using an air pump as the power source for the alkalization system. Manual addition of diisopropylamine is inconsistent among technicians, making it difficult to accurately guarantee the amount added. If problems arise, technicians often use pH test strips, but these have low accuracy. Furthermore, the influence of pH on sodium ion concentration leads to inaccurate measurement results. Using an air pump for bubbling results in diisopropylamine being carried into the air by the bubbles, which has a strong odor. Diisopropylamine is toxic, more so than methylamine and ethylamine. Its liquid and vapor irritate the eyes, skin, and respiratory tract, causing visual disturbances, skin burns, headaches, nausea, and vomiting. Repeated skin contact can cause allergic dermatitis, and inhalation of vapor can cause pulmonary edema. Diisopropylamine is flammable and poses a combustion hazard when exposed to open flames, high temperatures, or strong oxidizers. Its vapor can form explosive mixtures with air; being heavier than air, the vapor can spread considerably and flashback ignite upon contact with an ignition source, causing a fire. Diisopropylamine is also corrosive and can severely corrode aluminum, copper, and their alloys. Therefore, both manual and mechanical addition via bubbling will result in the leakage of diisopropylamine.

[0004] Meanwhile, the static method for determining sodium content is susceptible to contamination from the container, environment, and eluent from the reference electrode, and even from the dissolution of Na from the pNa glass electrode itself. + Therefore, it is difficult to detect trace amounts of Na. + In many important industrial sectors, such as power plant boiler water supply, steam turbine condensate, and high-purity water used in the semiconductor industry, very low levels of sodium (Na) have been detected. + It is difficult to meet the testing requirements using static measurements. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a self-adding sodium ion analyzer. By utilizing the Venturi effect of the variable-diameter channel structure, it adds ammonia during the sample falling process and alkalizes the sample to a pH value above 11. Simultaneously, it displays the corresponding pH value and sodium ion concentration, ensuring the accuracy of the sodium ion concentration.

[0006] The technical solution adopted in this invention is: a self-adding sodium ion analyzer, which includes a sample alkalization cup, an alkalization system, a measuring flow cell, a sodium ion electrode, a pH triple composite electrode, and an instrument display and control unit;

[0007] The sample alkalization cup is equipped with an ammonia gas inner tube, a sample inner tube, a mixing inner tube, and a sample chamber. A flow path reducer is located below the sample alkalization cup. The sample chamber inside the sample alkalization cup is connected to the sample inner tube below. One end of the ammonia gas inner tube is connected to the ammonia gas pipe, and the other end is connected to the sample inner tube. After the sample inner tube is connected to the ammonia gas inner tube, it becomes the mixing inner tube. The mixing inner tube is connected to the water-gas mixing pipe and then to the measurement flow cell.

[0008] The flow cell contains a sample buffer cell, a sodium ion detection cell, and a pH detection cell arranged sequentially. A sodium ion electrode is inserted in the sodium ion detection cell, and a pH triple-electrode electrode is inserted in the composite electrode cell. An inlet is located on the side of the sample buffer cell, and a connecting pipe is located at the bottom of the sample buffer cell, connecting the inlet, the sample buffer cell, and the sodium ion detection cell. The bottoms of the sodium ion detection cell and the pH detection cell are connected via an electrode cell connecting pipe. A drain pipe is located on the side of the pH detection cell.

[0009] In the alkalization system, the ammonia cylinder is connected to the sample alkalization cup via an ammonia gas pipe, and an ammonia valve is installed on the ammonia gas pipe; the bottom of the sample alkalization cup is connected to the sample buffer cell via a water-gas mixing pipe, and the sample buffer cell is then connected back to the ammonia cylinder via an ammonia recovery pipe, and an ammonia recovery valve is installed on the ammonia recovery pipe.

[0010] The instrument display control unit includes an instrument controller and a display screen. The instrument controller is electrically connected to the sodium ion electrode and the pH triple composite electrode.

[0011] Furthermore, the diameter of the sample chamber is larger than the diameter of the inner sample tube, and the diameter of the inner sample tube is smaller than the diameter of the water-air mixing tube, resulting in a Venturi effect at the inner sample tube.

[0012] Furthermore, the diameter of the sample inner tube is 0.1mm-5mm, and the length of the sample inner tube is 1-5cm; the part of the ammonia inner tube that contacts the sample inner tube is an inclined tube, and the angle between the ammonia inner tube and the sample inner tube is 45±15°.

[0013] Furthermore, the sample alkalization cup is also provided with an overflow port, and an overflow detector is installed on the pipeline connected to the overflow port. The overflow detector is electrically connected to the instrument controller.

[0014] Furthermore, the sample alkalization cup is also equipped with a sample inlet, which is directly connected to the on-site sampling tube for real-time monitoring of the sample in the sampling tube.

[0015] Furthermore, a drain pipe is provided on the side of the pH detection tank, and the drain pipe is flush with the bottom edge of the pH detection tank; a drain pump is provided at the drain pipe, and the drain pump is electrically connected to the instrument controller.

[0016] Furthermore, the centerline of the drain pipe and the buffer pool connecting pipe are at the same height, and the diameter of the drain pipe is larger than the diameter of the buffer pool connecting pipe.

[0017] Furthermore, the volume of the sample buffer cell is 1 / 10 to 1 / 5 of the capacity of the sample alkalization cup; the ammonia recovery pipe is installed on the top and side of the sample buffer cell.

[0018] Furthermore, the height difference between the water-air mixing tube at one end of the sample alkalization cup and the other end of the sample buffer cell is at least 20 cm.

[0019] The principle of this invention is to raise the pH of a water sample from approximately 7 to above 11 without the need for an external power source such as a pump. This is mainly achieved by utilizing the Venturi principle. Specifically, this involves developing a special Venturi tube (achieved through the coordinated use of multiple components, including variable diameter water sample tubing, gas flow path angle, water-gas mixing tube height, and ammonia closed-loop recovery). Other improvements include optimizing the flow cell structure, adding a sample buffer to control sample flow rate, reduce electrode response time, and eliminate small air bubble interference; adjusting the sensor sequence to place the sodium electrode before the pH electrode; adding a pH triple-electrode to measure the pH and temperature of the alkalized water sample, and serving as a reference electrode for the sodium electrode; and adding a sample evacuation function to prevent cross-contamination between different samples. During operation, the lab technician simply pours the water sample into the alkalization cup, and the water flows automatically through the flow cell under gravity to achieve alkalization and measurement, eliminating the need for a power source such as a pump. This also solves the industry problem of toxic gas volatilization, as only about 20 mL of sample is required.

[0020] The beneficial effects of this invention are as follows: The self-adding sodium ion analyzer of this invention achieves the following functions: First, the laboratory technician only needs to pour the water sample into the sample alkalization cup, and the instrument automatically alkalizes and measures the sodium ion. Second, it can automatically add diisopropylamine (without the need for a power source such as an air pump), and there is no volatilization of diisopropylamine during use, which can effectively protect the health of laboratory personnel. Third, it has a dynamic measurement function, with excellent repeatability and high accuracy when measuring low sodium levels. Fourth, it has a precise pH measurement function, ensuring the reliability of the measurement. Currently, there are more than 3,000 power plants of various sizes in China, with more than 10,000 related laboratory personnel. This invention can protect the health of these laboratory personnel. The self-adding sodium ion analyzer can more accurately measure the sodium ion content in boiler water and steam, playing an important role in the safe operation of power plant boilers. In addition, due to its high measurement accuracy, it can completely replace expensive imported sodium meters. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a self-adding sodium ammonia ion analyzer.

[0022] Figure 2 This is a schematic diagram of a self-adding sodium ammonia ion analyzer (with overflow port).

[0023] Figure 3 This is a schematic diagram of a self-adding sodium ammonia ion analyzer (with sample inlet).

[0024] Figure 4 This is a structural diagram of a sample alkalization cup (side-opening).

[0025] Figure 5 This is a structural diagram of a sample alkalization cup (top opening).

[0026] Figure 6 This is a structural diagram of a flow cell.

[0027] Figure 7 This is a graph showing the test results.

[0028] In the diagram: 1. Sample alkalization cup; 1a. Ammonia inner tube; 1b. Sample inner tube; 1c. Mixing inner tube; 1d. Overflow port; 1e. Sample chamber; 2. Measuring flow cell; 2a. Sample buffer cell; 2b. Sodium ion detection cell; 2c. Composite electrode detection cell; 2d. Drain pipe; 2e. Liquid inlet; 2f. Buffer cell connecting pipe; 2g. Electrode cell connecting pipe; 2h. Drain pipe; 3. Ammonia bottle; 4. pH triple composite electrode; 5. Sodium ion electrode; 6. Ammonia recovery pipe; 7. Water-gas mixing pipe; 8. Flow path variable diameter structure; 9. Ammonia pipe; 10. Overflow detector; 11. Instrument controller; 11a. Display screen; 12. Ammonia valve; 12a. Ammonia recovery valve; 13. Drain pump; 14. Sampling cup; 15. Sample inlet. Detailed Implementation

[0029] The present invention will be specifically described below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention, but are not limited thereto, unless otherwise stated.

[0030] The specific embodiments of the present invention are described in detail below with reference to the technical solutions:

[0031] Example 1

[0032] like Figure 1 As shown, the self-addition sodium ion analyzer mainly includes a sample alkalization cup 1, an alkalization system, a measuring flow cell 2, a sodium ion electrode 5, a pH triple composite electrode 4 (which includes a pH measuring electrode, a reference electrode, and a temperature sensor), and an instrument display and control unit. The instrument display and control unit includes an instrument controller 11 and a display screen 11a.

[0033] like Figure 4 or Figure 5 As shown, the sample alkalization cup 1 is equipped with an ammonia gas inner tube 1a, a sample inner tube 1b, a mixing inner tube 1c, and a sample chamber 1e.

[0034] A flow path variable diameter structure 8 is provided below the sample alkalization cup 1. The sample chamber 1e inside the sample alkalization cup 1 is connected to the sample inner tube 1b below. One end of the ammonia inner tube 1a is connected to the ammonia tube 9, and the other end of the ammonia inner tube 1a is connected to the sample inner tube 1b. After the sample inner tube 1b is connected to the ammonia inner tube 1a, it is set as the mixing inner tube 1c. The mixing inner tube 1c is connected to the measuring flow cell 2 through the water-gas mixing tube 7.

[0035] The diameter of sample chamber 1e is larger than the diameter of sample inner tube 1b, and the diameter of sample inner tube 1b is smaller than the diameter of water-gas mixing tube 7, forming a Venturi effect. The flow velocity at sample inner tube 1b increases, which facilitates the absorption of ammonia gas from ammonia gas in ammonia gas inner tube 1a connected to sample inner tube 1b.

[0036] In some specific embodiments, the diameter of the sample inner tube 1b is 0.1mm-5mm, and can be 2mm, 3mm, etc.; the length of the sample inner tube 1b is 1-5cm, and can be 2cm, 4cm, etc.; the diameter of the water-air mixing tube 7 is 4-8mm, and can be 4mm, 6mm or 8mm, but the diameter of the water-air mixing tube 7 must be greater than the diameter of the sample inner tube 1b.

[0037] In some specific embodiments, the portion of the ammonia inner tube 1a that contacts the sample inner tube 1b is an inclined tube, while the remaining portion can be either an inclined tube or a straight tube, and can be connected to the ammonia tube 9 (e.g. Figure 4 , Figure 5 (As shown). The angle between the ammonia inner tube 1a and the sample inner tube 1b is approximately 45 degrees.

[0038] In some specific implementations, such as Figure 2 As shown, the sample alkalization cup 1 is also equipped with an overflow port 1d, and an overflow detector 10 is installed on the pipeline connected to the overflow port 1d. The overflow detector 10 is electrically connected to the instrument controller 11. After the overflow detector 10 detects a signal, it triggers the switch signal in the instrument controller 11, and the automatic pneumatic instrument controller 11 performs measurement, so that the equipment realizes automatic detection of the sample.

[0039] In some specific implementations, such as Figure 3 As shown, the sample alkalization cup 1 is also equipped with a sample inlet 15. Sampling is not required without sampling cup 14. The sample inlet 15 can be connected to the on-site sampling tube, which can monitor the sample in the sampling tube in real time.

[0040] like Figure 6As shown, the flow cell 2 contains a sample buffer cell 2a, a sodium ion detection cell 2b, and a pH detection cell 2c arranged sequentially. A sodium ion electrode 5 is inserted in the sodium ion detection cell 2b. A pH triple composite electrode 4 is inserted in the composite electrode cell 2c, which is an electrode composed of a pH measuring electrode, a reference electrode, and a temperature sensor. An inlet 2e is located on the side of the sample buffer cell 2a, and a buffer cell connecting pipe 2f is located at the bottom of the sample buffer cell 2a, connecting the inlet 2e, the sample buffer cell 2a, and the sodium ion detection cell 2b. The bottoms of the sodium ion detection cell 2b and the pH detection cell 2c are connected by an electrode cell connecting pipe 2g. A drain pipe 2d is located on the side of the pH detection cell 2c.

[0041] In some specific embodiments, a drain pipe 2h is also provided on the side of the pH detection cell 2c, flush with the bottom edge of the pH detection cell 2c; a drain pump 13 is installed at the drain pipe 2h, and the drain pump 13 is electrically connected to the instrument controller 11. After the test is completed, before replacing the test sample, the drain pump 13 is started to remove the sample remaining in the buffer cell flow pipe 2f, the sodium ion detection cell 2b, and the bottom of the pH triple composite electrode 4, to avoid mixing with the replaced sample and affecting the test results. However, it should be noted that due to the special requirements of the electrode, if the test is not to be performed for a long time, such as several hours or a day later, after the last set of samples is tested, it is not necessary to remove the residual sample immediately. Instead, the electrode should be soaked in the sample solution to avoid damage to the electrode; only the sample remaining in the measuring flow cell 2 needs to be removed before the next use.

[0042] In some specific embodiments, the centerline of the drain pipe 2d and the buffer tank connecting pipe 2f are at the same height, and the diameter of the drain pipe 2d is larger than the diameter of the buffer tank connecting pipe 2f, so that the liquid can flow from the inlet 2e through the sample buffer tank 2a, the sodium ion detection tank 2b and the pH detection tank 2c in sequence, and finally be discharged to the waste tank through the waste pipe via the drain pipe 2d.

[0043] In some specific embodiments, the volume of the sample buffer cell 2a is approximately 1 / 10 to 1 / 5 of the capacity of the sample alkalization cup 1, such as 1 / 10, 1 / 8, or 1 / 5; this avoids negative pressure from bringing the water sample into the ammonia cylinder. The ammonia recovery pipe 6 can be installed at the top and side of the sample buffer cell 2a. When installed at the top, it provides more space for ammonia evaporation and further prevents the water sample from being brought into the ammonia cylinder, making it a better solution.

[0044] In some specific embodiments, the sodium ion electrode 5 and the pH triple composite electrode 4 are electrically connected to the instrument controller 11. The sodium ion electrode 5 and the pH triple composite electrode 4 transmit the detected sample data signals to the instrument controller 11, which are then displayed on the display screen 11a. The display screen 11a will display at least the data such as sodium ion concentration, pH value and temperature.

[0045] In the alkalization system, one end of the ammonia bottle 3 is connected to the sample alkalization cup 1 via an ammonia gas pipe 9, and an ammonia valve 12 is installed on the ammonia gas pipe 9. The bottom of the sample alkalization cup 1 is connected to the sample buffer cell 2a of the measuring flow cell 2 via a water-gas mixing pipe 7. The sample buffer cell 2a is then connected back to the ammonia bottle 3 via an ammonia recovery pipe 6, and an ammonia recovery valve 12a is installed on the ammonia recovery pipe 6. Both valves are open when in use and closed at other times to prevent ammonia from evaporating.

[0046] Ammonia bottle 3 → Sample alkalization cup 1 → Sample buffer cell 2a in the measurement flow cell 2 → Ammonia bottle 3, forming a circulation loop for ammonia gas flow; after the ammonia gas in ammonia bottle 3 evaporates, it flows along this loop, and some ammonia gas is absorbed by the sample and used to alkalize the sample. Ammonia gas is automatically replenished by evaporating in ammonia bottle 3 to ensure the pressure balance in the overall circulation loop.

[0047] In some specific embodiments, when the sample in the sample alkalization cup 1 flows completely into the measuring flow cell 2, the sample is partially sealed in the buffer cell connecting pipe 2f due to the forces of surface tension, capillary action, etc., so that the ammonia gas stops circulating in the entire ammonia gas circulation loop, which plays the role of automatic switching; thus, the ammonia gas valve 12 and ammonia gas recovery valve 12a do not need to be turned off when changing samples, which can achieve the effect of avoiding the volatilization of ammonia gas in the ammonia cylinder 3.

[0048] In some specific embodiments, in order to allow sufficient mixing time for the sample and ammonia, there are requirements for the length and / or height difference of the water-gas mixing tube 7. The height difference of the water-gas mixing tube 7 from one end of the bottom of the sample alkalization cup 1 to the other end of the sample buffer pool 2a is at least 20cm, which can ensure that the pH of the alkalized sample reaches above 11. If the height difference is less than 20cm, it can be achieved by extending the length of the water-gas mixing tube 7.

[0049] In a preferred embodiment, the diameter of the sample inner tube 1b is 2 mm, the length of the sample inner tube 1b is 2 cm, the height difference between the water-gas mixing tube 7 and the other end of the sample alkalization cup 1 is 20 cm, the angle between the ammonia inner tube 1a and the sample inner tube 1b is 45 degrees, and the volume of the sample buffer pool 2a is 1 / 8 of the capacity of the sample alkalization cup 1.

[0050] When operating using the preferred embodiments described above, the following steps are included:

[0051] S1. When measurement is required, open the ammonia valve 12 and the ammonia recovery valve 12a, and pour the sample to be tested from the sampling cup 14 into the sample alkalization cup 1.

[0052] S2. A 2cm long, 2mm diameter inner tube is located at the bottom of sample alkalization cup 1. The upper end connects to the water sample, and the lower end connects to ammonia gas. Utilizing the Venturi effect, the water sample and ammonia gas are thoroughly mixed here. Mixing continues through a water-gas mixing tube 7 at a certain height (20cm). After thorough mixing, the water sample and ammonia gas flow into sample buffer tank 2a. An ammonia gas recovery tube 6 connects sample buffer tank 2a to an ammonia cylinder, forming a closed-loop ammonia gas circuit. This ensures ammonia gas recovery, conserves ammonia usage, and prevents ammonia gas volatilization, protecting the health of laboratory personnel. Sample buffer tank 2a must have sufficient volume, approximately 1 / 3 the capacity of sample alkalization cup 1, to prevent negative pressure from drawing the water sample into the ammonia cylinder. After a series of alkalization processes, the pH value of the tested water sample increases from around 7 to above 11, and even from around 3 (as in a power plant cation exchange device) to above 11, thereby discharging H₂. + Impact, ensuring Na + The accuracy of the measurement.

[0053] Another function of the sample buffer cell is to eliminate the influence of small air bubbles on the sodium ion electrode. Because the mixture of water and ammonia produces small air bubbles, if these bubbles adhere to the sodium ion electrode bulb, they can affect measurement accuracy. In the sample buffer cell, these bubbles naturally rise and evaporate, and are then recovered through the ammonia recovery tube.

[0054] S3. The alkalized sample enters the measuring flow cell 2. A sodium ion electrode 5 and a pH triple composite electrode 4 are sequentially placed inside the measuring flow cell 2. The pH electrode 4 and the sodium ion electrode 5 are electrically connected to the instrument controller 11. After processing the electrode signals, the instrument controller 11 displays the Na+ signal on the display screen 11a. + Values ​​such as content, pH value, and temperature.

[0055] After alkalization, the test sample passes sequentially through sample buffer cell 2a, sodium ion detection cell 2b, and pH detection cell 2c in the measurement flow cell 2. The drain pipe 2d connects to the waste liquid tank via a waste liquid pipe. In the measurement flow cell 2, the alkalized water sample first passes through sodium ion detection cell 2b and then through pH detection cell 2c. This order cannot be changed because the efflorescence from the reference electrode will interfere with the measurement—Xie Shengluo, "Ion Selective Electrode Analysis Techniques".

[0056] The pH composite electrode 4 in this device consists of a pH measuring electrode, a reference electrode, and a temperature electrode. The reference electrode is Na. + The measuring electrode and the pH measuring electrode are shared; because the Na content is measured... + For accuracy, the pH value of the water sample after alkalization must be known. This invention's self-adding sodium ammonia ion analyzer simultaneously measures Na+. + It includes pH value measurement, so the accuracy of the measurement is guaranteed.

[0057] After alkalization, the test sample flows in from above the sodium electrode measuring bulb and out from below. Since the liquid level of the water sample in the sample buffer cell is relatively constant, the water flow rate is also relatively constant, which is conducive to sodium ion detection. After the water sample flows out, it enters the pH detection cell. The sodium ion detection cell and the pH detection cell form a connected cell, which together constitute two sets of galvanic cell measurement systems.

[0058] S4. At the end of the measuring flow cell 2 are the drain pipe 2h and the drain pump 13. The drain pipe 2h is located below the measuring flow cell and is connected to the sodium ion detection cell 2b and the composite electrode cell 2c. When the drain pump 13 is working, it can drain the water sample in the measuring flow cell completely. The laboratory technician only needs to press the self-reset switch, which is very convenient to use. This design is also very important, as it can drain the water sample from the previous measurement and wait for the next measurement, ensuring the accuracy of the measurement.

[0059] After the last measurement each day, do not press the reset switch. Ensure that there is alkalized water sample in the measurement flow cell to soak the sodium ion electrode and pH triple composite electrode, which will improve the response time of the next measurement.

[0060] Figure 7 Yes + The relationship between sodium ion concentration and different pH values ​​of water samples is shown in the figure. The synchronous changes in sodium ion concentration and alkalization pH value are evident: during the period marked in red (16:53-17:14), the alkalization pH value was only 10.2-10.3, which did not meet the strongly alkaline conditions required for sodium ion measurement. The measured sodium ion concentration at this time (0.62-0.67 μg / L) was significantly high. As the alkalization pH value increased to 11.3-11.5 (during the period marked in green, 17:19-17:27), the sodium ion reading returned to the normal level of 0.18-0.20 μg / L, indicating that the previous high sodium reading was due to measurement interference caused by insufficient alkalization of the water sample. The analyzer in this invention can simultaneously display pH value and sodium ion concentration, providing an accurate pH reference for the accurate measurement and analysis of sodium ions. The self-adding sodium ion analyzer of the present invention only requires the laboratory technician to pour the water sample into the sample alkalization cup, and the water can automatically alkalize and measure by relying on gravity to flow through the measuring flow cell. It does not require a power source such as an air pump, and can be compatible with measuring the pH value of cation bed water of about 3 and the pH value of boiler steam condensate of about 9.

[0061] The sodium ion analyzer features a sample alkalization cup for pouring in the water sample. At the bottom of the alkalization cup, two flow channels merge into one: one for the water sample and the other for the alkalizing gas. Utilizing the Venturi effect, by adjusting the diameter and tilt angle of the water sample and alkalizing gas channels, as well as the diameter and height of the water-gas mixing channel, the water sample and alkalizing gas are thoroughly mixed, raising the pH of the water sample from approximately 3 to above 11.

[0062] The valve is open when the sodium ion analyzer is working and is normally closed to prevent the evaporation of alkaline gases. Its angle can also be adjusted to accommodate water samples with different pH values. The flow cell structure is optimized, with the water sample flowing from top to bottom through the sodium electrode bulb and then from bottom to top through the pH electrode bulb. Based on the principle of communicating vessels, both the sodium and pH electrode bulbs are immersed in the water sample as it passes through, ensuring the electrodes are in the alkaline water sample after measurement. During the experimental measurement, many issues related to Na... + The exact relationship between Na content and the pH value of the alkalized water sample, i.e., how to accurately measure Na + To determine the content, the water sample to be measured must be alkalized to a pH value above 11.2. This invention's self-adding sodium ion analyzer is suitable for trace amounts of Na. + The research is of great help, especially for monitoring steam quality in large thermal power plants.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-adding sodium ammonia ion analyzer, characterized in that: The analyzer includes a sample alkalization cup (1), an alkalization system, a measurement flow cell (2), a sodium ion electrode (5), a pH triple composite electrode (4), and an instrument display and control unit; The sample alkalization cup (1) is equipped with an ammonia gas inner tube (1a), a sample inner tube (1b), a mixing inner tube (1c), and a sample chamber (1e). A flow path variable diameter structure (8) is set below the sample alkalization cup (1). The sample chamber (1e) inside the sample alkalization cup (1) is connected to the sample inner tube (1b) below. One end of the ammonia gas inner tube (1a) is connected to the ammonia gas tube (9), and the other end of the ammonia gas inner tube (1a) is connected to the sample inner tube (1b). After the sample inner tube (1b) is connected to the ammonia gas inner tube (1a), it is set as the mixing inner tube (1c). The mixing inner tube (1c) is connected to the water-gas mixing tube (7) and connected to the measuring flow cell (2). The flow cell (2) is equipped with a sample buffer cell (2a), a sodium ion detection cell (2b), and a pH detection cell (2c) in sequence. A sodium ion electrode (5) is inserted in the sodium ion detection cell (2b), and a pH triple composite electrode (4) is inserted in the composite electrode cell (2c). An inlet (2e) is provided on the side of the sample buffer cell (2a), and a buffer cell connecting pipe (2f) is provided at the bottom of the sample buffer cell (2a). The buffer cell connecting pipe (2f) connects the inlet (2e), the sample buffer cell (2a), and the sodium ion detection cell (2b). The bottoms of the sodium ion detection cell (2b) and the pH detection cell (2c) are connected by an electrode cell connecting pipe (2g). A drain pipe (2d) is provided on the side of the pH detection cell (2c). In the alkalization system, the ammonia bottle (3) is connected to the sample alkalization cup (1) through the ammonia pipe (9), and the ammonia pipe (9) is equipped with an ammonia valve (12); the bottom of the sample alkalization cup (1) is connected to the sample buffer pool (2a) through the water-gas mixing pipe (7), and the sample buffer pool (2a) is then connected back to the ammonia bottle (3) through the ammonia recovery pipe (6), and the ammonia recovery pipe (6) is equipped with an ammonia recovery valve (12a); The instrument display control unit includes an instrument controller (11) and a display screen (11a). The instrument controller (11) is electrically connected to the sodium ion electrode (5) and the pH triple composite electrode (4).

2. The self-ammoniating sodium ion analyzer of claim 1, wherein: The diameter of the sample chamber (1e) is larger than the diameter of the inner sample tube (1b), and the diameter of the inner sample tube (1b) is smaller than the diameter of the water-air mixing tube (7). The sample forms a Venturi effect at the inner sample tube (1b).

3. The self-ammoniating sodium ion analyzer of claim 1, wherein: The diameter of the sample inner tube (1b) is 0.1mm-5mm, and the length of the sample inner tube (1b) is 1-5cm; the part of the ammonia inner tube (1a) that contacts the sample inner tube (1b) is an inclined tube, and the included angle between the ammonia inner tube (1a) and the sample inner tube (1b) is 45±15°.

4. The self-ammoniating sodium ion analyzer of claim 1, wherein: An overflow port (1d) is also provided on the sample alkalization cup (1), and an overflow detector (10) is provided on the pipeline connected to the overflow port (1d). The overflow detector (10) is electrically connected to the instrument controller (11).

5. The self-addition sodium ammonia ion analyzer according to claim 1, characterized in that: The sample alkalization cup (1) is also provided with an inlet (15), which is directly connected to the on-site sampling tube for real-time monitoring of the sample in the sampling tube.

6. The self-addition sodium ammonia ion analyzer according to claim 1, characterized in that: A drain pipe (2h) is also provided on the side of the pH detection pool (2c), and the drain pipe (2h) is flush with the bottom edge of the pH detection pool (2c); a drain pump (13) is provided at the drain pipe (2h), and the drain pump (13) is electrically connected to the instrument controller (11).

7. The self-addition sodium ammonia ion analyzer according to claim 1, characterized in that: The centerline of the drain pipe (2d) and the buffer pool connecting pipe (2f) are at the same height, and the diameter of the drain pipe (2d) is larger than the diameter of the buffer pool connecting pipe (2f).

8. The self-ammoniating sodium ion analyzer of claim 1, wherein: The volume of the sample buffer pool (2a) is 1 / 10 to 1 / 5 of the capacity of the sample alkalization cup (1); the ammonia recovery pipe (6) is set on the top and side of the sample buffer pool (2a).

9. The self-ammoniating sodium ion analyzer of claim 1, wherein: The height difference between the water-air mixing tube (7) from one end of the bottom of the sample alkalization cup (1) to the other end of the sample buffer cell (2a) is at least 20 cm.

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